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Sample records for postirradiation tensile behavior

  1. The postirradiation tensile properties and microstructure of several vanadium alloys

    International Nuclear Information System (INIS)

    Braski, D.N.

    1988-01-01

    Tensile specimens of V-15Cr-5Ti, Vanstar-7, V-3Ti-1si, and V-20Ti were irradiated at 420/degrees/C in FFTF-MOTA to a damage level of 82 dpa. Helium was preimplanted to levels up to 480 appm in selected specimens using a modified tritium trick. Irradiation hardening was the dominant effect influencing the postirradiation tensile properties, and it markedly increased the yield strength and reduced the total elogation. The V-15Cr-5Ti alloy was very sensitive to helium embrittlement, but Vanstar-7 and V-3Ti-1Si were only slightly affected. Without helium, negligible swelling (<1%) were measured in V-3Ti-1Si and V-20Ti. Preimplanted helium increased swelling in V-3Ti-1Si by increasing cavity nucleation. 11 refs., 11 figs., 3 tabs

  2. Postirradiation tensile properties of Mo and Mo alloys irradiated with 600 MeV protons

    International Nuclear Information System (INIS)

    Mueller, G.V.; Gavillet, D.; Victoria, M.; Martin, J.L.

    1994-01-01

    Tensile specimens of pure Mo and Mo-5 Re, Mo-41 Re and TZM alloys have been irradiated with 600 MeV protons in the PIREX facility at 300 and 660 K to 0.5 dpa. Results of the postirradiation tensile testing show a strong radiation hardening and a severe loss of ductility for all the materials tested at room temperature. ((orig.))

  3. Measurement of the yield and tensile strengths of neutron-irradiated and post-irradiation recovered vessel steels with notched specimens

    International Nuclear Information System (INIS)

    Valiente, A.

    1996-01-01

    Tensile circumferentially notched bars are examined as test specimens for measuring the yield and tensile strengths of nuclear pressure vessel steels under several conditions of irradiation and temperature that a vessel can experience during its service life, including recovery post-irradiation treatment. For all the vessel steels, notch geometries and conditions explored, it has been found that notched specimens fail by plastic collapse, and simple formulae have been derived that allow the yield and tensile strengths to be determined from the yielding and plastic collapse load of a notched specimen. Values measured in this way show good agreement with those measured by the standard tensile test method. (orig.)

  4. Postirradiation deformation behavior in ferritic Fe-Cr alloys

    International Nuclear Information System (INIS)

    Hamilton, M.L.; Gelles, D.S.; Gardner, P.L.

    1992-06-01

    It has been demonstrated that fast-neutron irradiation produces significant hardening in simple Fe-(3-18)Cr binary alloys irradiated to about 35 dpa in the temperature range 365 to 420 degrees C, whereas irradiation at 574 degrees C produces hardening only for 15% or more chromium. The irradiation-induced changes in tensile properties are discussed in terms of changes in the power law work-hardening exponent. The work-hardening exponent of the lower chromium alloys decreased significantly after low-temperature irradiation (≤ 420 degrees C) but increased after irradiation at 574 degrees C. The higher chromium alloys failed either in cleavage or in a mixed ductile/brittle fashion. Deformation microstructures are presented to support the tensile behavior

  5. Tensile and fracture behavior of polymer foams

    International Nuclear Information System (INIS)

    Kabir, Md. E.; Saha, M.C.; Jeelani, S.

    2006-01-01

    Tensile and mode-I fracture behavior of cross-linked polyvinyl chloride (PVC) and rigid polyurethane (PUR) foams are examined. Tension tests are performed using prismatic bar specimens and mode-I fracture tests are performed using single edge notched bend (SENB) specimens under three-point bending. Test specimens are prepared from PVC foams with three densities and two different levels of cross-linking, and PUR foam with one density. Tension and quasi-static fracture tests are performed using a Zwick/Rowell test machine. Dynamic fracture tests are performed using a DYNATUP model 8210 instrumented drop-tower test set up at three different impact energy levels. Various parameters such as specimen size, loading rate, foam density, cross-linking, crack length, cell orientation (flow and rise-direction) and solid polymer material are studied. It is found that foam density and solid polymer material have a significant effect on tensile strength, modulus, and fracture toughness of polymer foams. Level of polymer cross-linking is also found to have a significant effect on fracture toughness. The presence of cracks in the rise- and flow direction as well as loading rate has minimal effect. Dynamic fracture behavior is found to be different as compared to quasi-static fracture behavior. Dynamic fracture toughness (K d ) increases with impact energy. Examination of fracture surfaces reveals that the fracture occurs in fairly brittle manner for all foam materials

  6. Tensile behavior and tension stiffening of reinforced concrete

    International Nuclear Information System (INIS)

    Choun, Young Sun; Seo, Jeong Moon

    2001-03-01

    For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building

  7. Effects of post-irradiation annealing on the transformation behavior of Ti-Ni alloys

    International Nuclear Information System (INIS)

    Kimura, A.; Tsuruga, H.; Morimura, T.; Misawa, T.; Miyazaki, S.

    1993-01-01

    Recovery processes of martensitic transformation of neutron irradiated Ti-50.0, 50.5 and 51.0 at.%Ni alloys during post-irradiation annealing were investigated by means of differential scanning calorimetry (DSC), tensile tests and transmission electron microscope (TEM) observations. Neutron irradiation up to a fluence of 1.2x10 24 n/cm 2 at 333 K suppressed the martensitic transformation as well as the stress-induced martensitic transformation of these alloys above 150 K. The TEM observations revealed that the disordered zones containing small defect clusters in high density were formed in the neutron irradiated Ti-Ni alloys. The DSC measurements also showed that the post-irradiation annealing caused recovery of the transformation of which the progress depended on the annealing temperature and period. A significant retardation of the recovery was recognized in the Ti-51.0 at.%Ni alloy in comparison with the Ti-50.0 at.%Ni alloy. From the shifts in the transformation temperature upon isothermal annealing at various annealing temperatures, the activation energies of the recovery process of the transformation in the neutron irradiated Ti-50.0 and 51.0 at.%Ni alloys were evaluated by a cross-cut method to be 1.2 eV and 1.5 eV, respectively. The recovery of the transformation was ascribed to the re-ordering resulting from decomposition of vacancy clusters, and those obtained values of the activation energy were considered to be the sum of the migration energy of vacancy and the binding energy of vacancy-vacancy cluster. The retardation of the recovery in the Ti-51.0 at%Ni alloy was interpreted in terms of large binding energy in this alloy due to the off-stoichiometry. (author)

  8. Tensile behavior of borated stainless steels

    International Nuclear Information System (INIS)

    Stephens, J.J. Jr.; Sorenson, K.B.

    1991-01-01

    Borated stainless steel tensile testing is being conducted at Sandia National Laboratories (SNL). The goal of the test program is to provide data to support a code case inquiry to the ASME Boiler and Pressure Vessel Code, Section III. The adoption by ASME facilitates a material's qualification for structural use in transport cask applications. For transport cask basket applications, the potential advantage to using borated stainless steel arises from the fact that the structural and criticality control functions can be combined into one material. This can result in a decrease in net section thickness of the basket web (increased payload capacity) and eliminates the fabrication process and cost of attaching a discrete boron poison material to the basket web. In addition, adding borate stainless steel to the inventory of acceptable structural material provides the Department of Energy (DOE) and its cask contractors an alternative to current proposed materials which have not been qualified for structural service. The test program at SNL involves procuring material, machining test specimens, and conducting the tensile tests. From test measurements obtained so far, general trends indicate that tensile properties (yield strength and ultimate strength) increase with boron content and are in all cases superior to the minimum required properties established in A-240, Type 304, a typical grade of austenitic stainless steel. Therefore, in a designed basket, web thicknesses using borated stainless steel would be comparable to or thinner tan an equivalent basket manufactured from a typical stainless steel without boron additions. General trends from test results indicate that ductilities decrease with increasing boron content

  9. Fracture behavior of nuclear graphites under tensile impact loading

    International Nuclear Information System (INIS)

    Ugachi, Hirokazu; Ishiyama, Shintaro; Eto, Motokuni

    1994-01-01

    Impact tensile strength test was performed with two kinds of HTTR graphites, fine grained isotropic graphite, IG-11 and coarse grained near isotropic graphite, PGX and deformation and fracture behavior under the strain rate of over 100s -1 was measured and the following results were derived: (1) Tensile strength for IG-11 graphite does not depend on the strain rate less than 1 s -1 , but over 1 s -1 , tensile strength for IG-11 graphite increase larger than that measured under 1 s -1 . At the strain rate more than 100 s -1 , remarkable decrease of tensile strength for IG-11 graphite was found. Tensile strength of PGX graphite does not depend on the strain rate less than 1 s -1 , but beyond this value, the sharp tensile strength decrease occurs. (2) Under 100 s -1 , fracture strain for both graphites increase with increase of strain rate and over 100 s -1 , drastic increase of fracture strain for IG-11 graphite was found. (3) At the part of gage length, volume of specimen increase with increase of tensile loading level and strain rate. (4) Poisson's ratio for both graphites decrease with increase of tensile loading level and strain rate. (5) Remarkable change of stress-strain curve for both graphites under 100 s -1 was not found, but over 100 s -1 , the slope of these curve for IG-11 graphite decrease drastically. (author)

  10. Statistical behavior of the tensile property of heated cotton fiber

    Science.gov (United States)

    The temperature dependence of the tensile property of single cotton fiber was studied in the range of 160-300°C using Favimat test, and its statistical behavior was interpreted in terms of structural changes. The tenacity of control cotton fiber was well described by the single Weibull distribution,...

  11. Data characterizing tensile behavior of cenosphere/HDPE syntactic foam.

    Science.gov (United States)

    Kumar, B R Bharath; Doddamani, Mrityunjay; Zeltmann, Steven E; Gupta, Nikhil; Ramakrishna, Seeram

    2016-03-01

    The data set presented is related to the tensile behavior of cenosphere reinforced high density polyethylene syntactic foam composites "Processing of cenosphere/HDPE syntactic foams using an industrial scale polymer injection molding machine" (Bharath et al., 2016) [1]. The focus of the work is on determining the feasibility of using an industrial scale polymer injection molding (PIM) machine for fabricating syntactic foams. The fabricated syntactic foams are investigated for microstructure and tensile properties. The data presented in this article is related to optimization of the PIM process for syntactic foam manufacture, equations and procedures to develop theoretical estimates for properties of cenospheres, and microstructure of syntactic foams before and after failure. Included dataset contains values obtained from the theoretical model.

  12. Predicting the in-reactor mechanical behavior of Zr-2.5Nb pressure tubes from postirradiation microstructural examination data

    International Nuclear Information System (INIS)

    Griffiths, M.; Davies, P.H.; Davies, W.G.; Sagat, S.

    2002-01-01

    Postirradiation microstructure examinations of Zr-2.5Nb pressure tubes removed from service in CANDU reactors have shown clear trends in the dislocation structure and the state of the β-phase, as a function of operating temperature, neutron flux, and time. These microstructural parameters correlate well with changes in the mechanical properties. For example, the rapid increase in dislocation loop density in the early stages of irradiation corresponds with a rapid increase in tensile strength and DHC velocity, and a corresponding decrease in fracture toughness. There is also a strong negative correlation between the degree of β-phase decomposition and DHC velocity. In addition to the effects of microstructure evolution on the mechanical properties, changes in the a-type and c-component dislocation loop densities also affect irradiation deformation (creep and growth). Statistical analyses of the irradiation microstructure data have been used to derive empirical relationships between dislocation densities and β-phase structure with temperature, flux, and time. The relationships thus derived are useful in predicting where the mechanical properties are most affected by the in-reactor operating conditions. The predictions are compared with mechanical test data for samples from various axial and circumferential locations of 42 pressure tubes removed from operating CANDU reactors. The results are discussed in terms of the mechanisms controlling tensile strength, fracture, delayed-hydride-cracking, and in-reactor deformation. (author)

  13. Tensile creep behavior in an advanced silicon nitride

    International Nuclear Information System (INIS)

    Lofaj, F.

    2000-01-01

    Tensile creep behavior and changes in the microstructure of the advanced silicon nitride, SN 88M, were studied at temperatures from 1250 to 1400 C to reveal the creep resistance and lifetime-controlling processes. Assuming power law dependence of the minimum strain rate on stress, stress exponents from 6 to 8 and an apparent activation energy of 780 kJ/mol were obtained. Extensive electron microscopy observations revealed significant changes in the crystalline secondary phases and creep damage development. Creep damage was classified in two groups: 'inter-granular' defects in the amorphous boundary phases, and 'intra-granular' defects in silicon nitride grains. The inter-granular defects involved multigrain junction cavities, two-grain junction cavities, microcracks and cracks. The intra-granular defects included broken large grains, small symmetrical and asymmetrical cavities, and crack-like intragranular cavities. Cavities are generated continuously during the whole deformation starting from the threshold strain of ∝0.1%, and they contribute linearly to the tensile strain. Cavities produce more than 90% of the total tensile strain, and it is concluded that cavitation is the main creep mechanism in silicon nitride ceramics. The multigrain junction cavities are considered to be the most important for generating new volume and producing tensile strain. The Luecke and Wiederhorn (L and W) creep model, based on cavitation at multigrain junctions according to an exponential law, was proven to correspond to the stress dependence of the minimum strain rate. A qualitative model based on the L and W model was suggested and expanded to include intragranular cavitation. The basic mechanisms involve a repeating of the sequence grain boundary sliding (GBS) => cavitation at multigrain junctions => viscous flow and dissolution-precipitation. (orig.)

  14. The tensile behavior of GH3535 superalloy at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Han, F.F.; Zhou, B.M.; Huang, H.F.; Leng, B.; Lu, Y.L. [Thorium Molten Salts Reactor Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences (China); Dong, J.S. [Superalloy Division, Institute of Metal Research, Chinese Academy of Sciences (China); Li, Z.J., E-mail: lizhijun@sinap.ac.cn [Thorium Molten Salts Reactor Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences (China); Zhou, X.T. [Thorium Molten Salts Reactor Center, Shanghai Institute of Applied Physics, Chinese Academy of Sciences (China)

    2016-10-01

    The tensile behavior of GH3535 alloy has been investigated at strain rates of 8.33 × 10{sup −5}/s{sup −1}–8.33 × 10{sup −3}/s{sup −1}, in the temperature range of 25–800 °C. The results showed that the ultimate tensile strength was decreased with increasing temperature and increased with rising strain rate, whereas the yield strength kept almost a constant value at the temperature range from 550 to 800 °C in all strain rates test. The formation of M{sub 12}C carbides at the grain boundary during the tension process played an important role in increasing the yield strength of the alloy at elevated temperatures. But inhomogeneous deformation at 650 °C resulted in the minimum ductility of the alloy. Additionally, various types of serrations were noticed on the stress-strain curves for the alloy tested in the temperature range of 500–800 °C. Normal Portevin-Le Chatelier (PLC) effect and positive strain rate sensitivity were observed in this alloy. Type A and A + B serrations were presented to stress-strain curves at temperatures below 650 °C, whereas type C serration was noticed when the temperature rose above 650 °C. The analysis suggested that the interactions between substitutional solutes migration and mobile dislocations were the main reason for the serrated flow behavior in this alloy. - Highlights: • The tensile behavior of GH3535 alloy at elevated temperature was studied. • The yield strength anomaly was observed in the temperature range from 550 to 800 °C. • The formation of M{sub 12}C improves the grain boundary strength to a certain extent. • Inhomogeneous deformation at 650 °C results in the ductility loss of the alloy. • The interaction between solute atoms and dislocations results in the PLC effect.

  15. Tensile Fracture Behavior of Progressively-Drawn Pearlitic Steels

    Directory of Open Access Journals (Sweden)

    Jesús Toribio

    2016-05-01

    Full Text Available In this paper a study is presented of the tensile fracture behavior of progressively-drawn pearlitic steels obtained from five different cold-drawing chains, including each drawing step from the initial hot-rolled bar (not cold-drawn at all to the final commercial product (pre-stressing steel wire. To this end, samples of the different wires were tested up to fracture by means of standard tension tests, and later, all of the fracture surfaces were analyzed by scanning electron microscopy (SEM. Micro-fracture maps (MFMs were assembled to characterize the different fractographic modes and to study their evolution with the level of cumulative plastic strain during cold drawing.

  16. Importance of Tensile Strength on the Shear Behavior of Discontinuities

    Science.gov (United States)

    Ghazvinian, A. H.; Azinfar, M. J.; Geranmayeh Vaneghi, R.

    2012-05-01

    In this study, the shear behavior of discontinuities possessing two different rock wall types with distinct separate compressive strengths was investigated. The designed profiles consisted of regular artificial joints molded by five types of plaster mortars, each representing a distinct uniaxial compressive strength. The compressive strengths of plaster specimens ranged from 5.9 to 19.5 MPa. These specimens were molded considering a regular triangular asperity profile and were designed so as to achieve joint walls with different strength material combinations. The results showed that the shear behavior of discontinuities possessing different joint wall compressive strengths (DDJCS) tested under constant normal load (CNL) conditions is the same as those possessing identical joint wall strengths, but the shear strength of DDJCS is governed by minor joint wall compressive strength. In addition, it was measured that the predicted values obtained by Barton's empirical criterion are greater than the experimental results. The finding indicates that there is a correlation between the joint roughness coefficient (JRC), normal stress, and mechanical strength. It was observed that the mode of failure of asperities is either pure tensile, pure shear, or a combination of both. Therefore, Barton's strength criterion, which considers the compressive strength of joint walls, was modified by substituting the compressive strength with the tensile strength. The validity of the modified criterion was examined by the comparison of the predicted shear values with the laboratory shear test results reported by Grasselli (Ph.D. thesis n.2404, Civil Engineering Department, EPFL, Lausanne, Switzerland, 2001). These comparisons infer that the modified criterion can predict the shear strength of joints more precisely.

  17. Direct assessment of tensile stress-crack opening behavior of Strain Hardening Cementitious Composites (SHCC)

    DEFF Research Database (Denmark)

    Pereira, Eduardo B.; Fischer, Gregor; Barros, Joaquim A.O.

    2012-01-01

    -deformation behavior of these materials is therefore of great importance and is frequently carried out by characterizing the material tensile stress–strain behavior. In this paper an alternative approach to evaluate the tensile performance of SHCC is investigated. The behavior of the material in tension is studied...

  18. Analysis on dynamic tensile extrusion behavior of UFG OFHC Cu

    Science.gov (United States)

    Park, Kyung-Tae; Park, Leeju; Kim, Hak Jun; Kim, Seok Bong; Lee, Chong Soo

    2014-08-01

    Dynamic tensile extrusion (DTE) tests with the strain rate order of ~105 s-1 were conducted on coarse grained (CG) Cu and ultrafine grained (UFG) Cu. ECAP of 16 passes with route Bc was employed to fabricate UFG Cu. DTE tests were carried out by launching the sphere samples to the conical extrusion die at a speed of ~475 m/sec in a vacuumed gas gun system. UFG Cu was fragmented into 3 pieces and showed a DTE elongation of ~340%. CG Cu exhibited a larger DTE elongation of ~490% with fragmentation of 4 pieces. During DTE tests, dynamic recrystallization occurred in UFG Cu, but not in CG Cu. In order to examine the DTE behavior of CG Cu and UFG Cu under very high strain rates, a numerical analysis was undertaken by using a commercial finite element code (LS-DYNA 2D axis-symmetric model) with the Johnson - Cook model. The numerical analysis correctly predicted fragmentation and DTE elongation of CG Cu. But, the experimental DTE elongation of UFG Cu was much smaller than that predicted by the numerical analysis. This difference is discussed in terms of microstructural evolution of UFG Cu during DTE tests.

  19. Numerical Study on the Tensile Behavior of 3D Four Directional Cylindrical Braided Composite Shafts

    Science.gov (United States)

    Zhao, Guoqi; Wang, Jiayi; Hao, Wenfeng; Liu, Yinghua; Luo, Ying

    2017-10-01

    The tensile behavior of 3D four directional cylindrical braided composite shafts was analyzed with the numerical method. The unit cell models for the 3D four directional cylindrical braided composite shafts with various braiding angles were constructed with ABAQUS. Hashin's failure criterion was used to analyze the tensile strength and the damage evolution of the unit cells. The influence of the braiding angle on the tensile behavior of the 3D four directional cylindrical braided composite shafts was analyzed. The numerical results showed that the tensile strength along the braiding direction increased as the braiding angle decreased. These results should play an integral role in the design of braiding composites shafts.

  20. Molecular Dynamics Simulations of Tensile Behavior of Copper

    OpenAIRE

    Sainath, G.; Srinivasan, V. S.; Choudhary, B. K.; Mathew, M. D.; Jayakumar, T.

    2014-01-01

    Molecular dynamics simulations on tensile deformation of initially defect free single crystal copper nanowire oriented in {100} has been carried out at 10 K under adiabatic and isothermal loading conditions. The tensile behaviour was characterized by sharp rise in stress in elastic regime followed by sudden drop at the point of dislocation nucleation. The important finding is that the variation in dislocation density is correlated with the observed stress-strain response. Several interesting ...

  1. Effect of Thermal Cycling on the Tensile Behavior of CF/AL Fiber Metal Laminates

    Directory of Open Access Journals (Sweden)

    Muhammad Farhan Noor

    2017-09-01

    Full Text Available The objective of this research work was to estimate the effect of thermal cycling on the tensile behavior of CARALL composites. Fiber metal laminates (FMLs, based on 2D woven carbon fabric and 2024-T3 Alclad aluminum alloy sheet, was manufactured by pressure molding technique followed by hand layup method. Before fabrication, aluminum sheets were anodized with phosphoric acid to produce micro porous alumina layer on surface. This micro-porous layer is beneficial to produce strong bonding between metal and fiber surfaces in FMLs. The effect of thermal cycling (-65 to +70ºC on the tensile behavior of Cf/Al based FML was studied. Tensile strength was increased after 10 thermal cycles, but it was slightly decreased to some extent after 30, and 50 thermal cycles. Tensile modulus also shown the similar behavior as that of tensile strength.

  2. Tensile and high cycle fatigue behaviors of high-Mn steels at 298 and 110 K

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Wongyu; Jeong, Daeho; Sung, Hyokyung; Kim, Sangshik, E-mail: sang@gnu.ac.kr

    2017-02-15

    Tensile and high cycle fatigue behaviors of high-Mn austenitic steels, including 25Mn, 25Mn0.2Al, 25Mn0.5Cu, 24Mn4Cr, 22Mn3Cr and 16Mn2Al specimens, were investigated at 298 and 110 K. Depending on the alloying elements, tensile ductility of high-Mn steels either increased or decreased with decreasing temperature from 298 to 110 K. Reasonable correlation between the tendency for martensitic tranformation, the critical twinning stress and the percent change in tensile elongation suggested that tensile deformation of high-Mn steels was strongly influenced by SFE determining TRIP and TWIP effects. Tensile strength was the most important parameter in determining the resistance to high cycle fatigue of high-Mn steels with an exceptional work hardening capability at room and cryogenic temperatures. The fatigue crack nucleation mechanism in high-Mn steels did not vary with decreasing tempertature, except Cr-added specimens with grain boundary cracking at 298 K and slip band cracking at 110 K. The EBSD (electron backscatter diffraction) analyses suggested that the deformation mechanism under fatigue loading was significantly different from tensile deformation which could be affected by TRIP and TWIP effects. - Highlights: •The resistances to HCF of various high-Mn steels were measured. •The variables affecting tensile and HCF behaviors of high-Mn steels were assessed. •The relationship between tensile and the HCF behaviors of high-Mn steels was established.

  3. Tensile behavior of EUROFER ODS steel after neutron irradiation up to 16.3 dpa between 250 and 450 °C

    International Nuclear Information System (INIS)

    Materna-Morris, Edeltraud; Lindau, Rainer; Schneider, Hans-Christian; Möslang, Anton

    2015-01-01

    Highlights: • The first 9%CrWVTa steel (0.5% Y_2O_3), EUROFER ODS HIP, have been neutron irradiated up to 16.3 dpa, between 250 and 450 °C, in the High Flux Reactor (HFR). • After post-irradiation tensile tests, there was not any increase of the upper yield strength or strain localization after irradiation which is typical of RAFM steels. • Initially higher yield strength, R_p_0_._2, and distinctive tensile strength, R_m, of EUROFER ODS HIP compared to EUROFER97 steel. • These values increased due to the neutron irradiation at lower irradiation temperatures. - Abstract: During the development of structural material for future fusion reactors, a 50 kg heat of reduced-activation ferritic-martensitic 9%CrWVTa steel with nanoscaled Y_2O_3-particles, EUROFER97 ODS HIP, was produced using powder metallurgy fabrication technology. This first batch of EUROFER97 ODS HIP and, for comparison, the steel EUROFER97 were prepared for a post-irradiation tensile test program. During neutron irradiation in the HFR (High Flux Reactor, The Netherlands), an accumulated dose of up to 16.3 dpa was reached for 771 days at full power, with the irradiation temperature ranging between 250 and 450 °C. During the post-examinations, all specimens showed the highest tensile strength at lower irradiation temperatures between 250 and 350 °C. However, ODS-alloy and steel were found to clearly differ in the mechanical behavior, which could be documented by fully instrumented tensile tests. In the un-irradiated state, tensile strength of the ODS-alloy already was increased considerably by about 60% compared to the steel. Strengthening was further increased by another 20% after neutron irradiation, but with a much better ductility than observed in the steel. The typical irradiation-induced strain localization of EUROFER97 or RAFM steels could not be observed in the EUROFER97 ODS HIP alloy.

  4. Irradiation Behavior and Post-Irradiation Examinations of an Acoustic Sensor Using a Piezoelectric Transducer

    International Nuclear Information System (INIS)

    Lambert, T.; Zacharie-Aubrun, I.; Hanifi, K.; Valot, Ch.; Fayette, L.; Rosenkantz, E.; Ferrandis, J.Y.; Tiratay, X.

    2013-06-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. In the framework of high burn-up fuel experiments under transient operating conditions, an innovative sensor based on acoustic method was developed by CEA and IES (Southern Electronic Institute).This sensor is used to determine the on-line composition of the gases located in fuel rodlet free volume and thus, allows calculating the molar fractions of fission gases and helium. The main principle of the composition determination by acoustic method consists in measuring the time of flight of an acoustic signal emitted and reflected in a specific cavity. A piezoelectric transducer, driven by a pulse generator, generates the acoustic wave in the cavity. The piezoelectric transducer is a PZT ceramic disk, mainly consisting of lead, zirconium and titanium. This acoustic method was tested with success during a first experiment called REMORA 3, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. However, during the irradiation test, acoustic signal degradation was observed, mainly due to irradiation effect but also due to the increasing of the gas temperature. Despite this acoustic signal degradation, the time of flight measurements were carried out with good accuracy throughout the test, thanks to the development of a more efficient signal processing. After experiment, neutronic calculations were performed in order to determine neutron fluence at the level of the piezoelectric transducer. In order to have a better understanding of the acoustic sensor behavior under irradiation, Post Irradiation Examination program was done on piezoelectric transducer and on acoustic coupling material too. These examinations were also realized on a non-irradiated acoustic sensor built in the same conditions and with the same materials and the same

  5. Tensile behavior of irradiated manganese-stabilized stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Tensile tests were conducted on seven experimental, high-manganese austenitic stainless steels after irradiation up to 44 dpa in the FFTF. An Fe-20Mn-12Cr-0.25C base composition was used, to which various combinations of Ti, W, V, B, and P were added to improve strength. Nominal amounts added were 0.1% Ti, 1% W, 0.1% V, 0.005% B, and 0.03% P. Irradiation was carried out at 420, 520, and 600{degrees}C on the steels in the solution-annealed and 20% cold-worked conditions. Tensile tests were conducted at the irradiation temperature. Results were compared with type 316 SS. Neutron irradiation hardened all of the solution-annealed steels at 420, 520, and 600{degrees}C, as measured by the increase in yield stress and ultimate tensile strength. The steel to which all five elements were added to the base composition showed the least amount of hardening. It also showed a smaller loss of ductility (uniform and total elongation) than the other steels. The total and uniform elongations of this steel after irradiation at 420{degrees}C was over four times that of the other manganese-stabilized steels and 316 SS. There was much less difference in strength and ductility at the two higher irradiation temperatures, where there was considerably less hardening, and thus, less loss of ductility. In the cold-worked condition, hardening occured only after irradiation at 420{degrees}C, and there was much less difference in the properties of the steels after irradiation. At the 420{degrees}C irradiation temperature, most of the manganese-stabilized steels maintained more ductility than the 316 SS. After irradiation at 420{degrees}C, the temperature of maximum hardening, the steel to which all five of the elements were added had the best uniform elongation.

  6. The characteristics of ultra-high performance concrete and cracking behavior of reinforced concrete tensile specimens

    Directory of Open Access Journals (Sweden)

    H.A. Rahdar

    2016-09-01

    Full Text Available The tensile behavior of concrete depends on some factors such as member dimensions, reinforcement ratio, diameter of rebar, strength and elasticity modulus of material. In this research the experimental method is used to examine the characteristics and the behavior of ultra-high performance concrete on the tensile behavior of concrete members reinforced by steel rebar. The results show that increasing the rebar cover on diameter rebar ratio (C/d increases the initial stiffening before the cracking stage in concrete. Also, by increasing of reinforcement ratio the cracking space decreased.

  7. The tensile deformation behavior of nuclear-grade isotropic graphite posterior to hydrostatic loading

    International Nuclear Information System (INIS)

    Yoda, S.; Eto, M.

    1983-01-01

    The effects of prehydrostatic loading on microstructural changes and tensile deformation behavior of nuclear-grade isotropic graphite have been examined. Scanning electron micrographs show that formation of microcracks associated with delamination between basal planes occurs under hydrostatic loading. Hydrostatic loading on specimens results in the decrease in tensile strength and increase in residual strain generated by the applied tensile stress at various levels, indicating that the graphite material is weakened by hydrostatic loading. A relationship between residual strain and applied tensile stress for graphite hydrostatically-loaded at several pressure levels can be approximately expressed as element of= (AP + B) sigmasup(n) over a wide range hydrostatic pressure, where element of, P and sigma denote residual strain, hydrostatic pressure and applied tensile stress, respectively; A, B and n are constant. The effects of prehydrostatic loading on the tensile stress-strain behavior of the graphite were examined in more detail. The ratio of stress after hydrostatic loading to that before hydrostatic loading on the stress-strain relationship remains almost unchanged irrespective of strain. (orig.)

  8. Influence of sodium evnironment on the uniaxial tensile behavior of titanium modified type 316 stainless steel

    International Nuclear Information System (INIS)

    Natesan, K.; Chopra, O.K.; Kassner, T.F.

    1978-01-01

    True stress-true strain tensile data have been obtained for titanium modified type 316 stainless steel in the solution annealed condition and after exposure to a flowing sodium environment at temperature of 700, 650, 600 and 550 0 C. The specimens were exposed to sodium for times between 120 and 5012 h to produce carbon penetration depths in the range 0.05-0.30 mm. The Voce equation was used to describe tensile flow curves for plastic strains above 0.005. The results showed that, when compared with solution annealed specimens, the tensile flow behavior of the sodium exposed specimens is characterized by a higher strain hardening rate, which decreases rapidly as the flow stress increases. The loss in tensile ductility of the material due to carburization in sodium environment was found to be minimal. (Auth.)

  9. High-rate tensile behavior of steel fiber-reinforced concrete for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Jin; Park, Gi-Joon [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Kim, Dong Joo, E-mail: djkim75@sejong.ac.kr [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Moon, Jae Heum; Lee, Jang Hwa [Korea Institute of Construction Technology, 2311 Daewha-Dong, Ilsan-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea, Republic of)

    2014-01-15

    Highlights: • The final goal is to develop a fiber reinforced concrete for containment buildings. • High rate tensile behavior of FRC was investigated. • Strain energy frame impact machine was used for tensile impact tests. • Different rate sensitivity of FRC was found according to the type fiber. • Adding more fibers by increasing S/a is positive for higher impact resistance of FRC. -- Abstract: The direct tensile behavior of fiber-reinforced concrete (FRC) at high strain rates were investigated for their potential to enhance the resistance of the containment building of nuclear power plants (NPPs) against aircraft impact. Two types of deformed steel, hooked (H) and twisted (T) fibers were employed. To improve the tensile resistance of FRCs even at higher rates by adding more fibers, the mixture of concrete was modified by either increasing the sand-to-coarse aggregate ratio or decreasing the maximum size of coarse aggregate. All FRC specimens produced two to six times greater tensile strength and one to five times higher toughness at high strain rates (4–53 s{sup −1}) than those at a static rate (0.000167 s{sup −1}). T-fiber generally produced higher tensile strength and toughness than H-fiber at both static and high rates. Although both fibers showed favorable rate sensitivity, T-fiber produced much greater enhancement, at higher strain rates, in tensile strength and slightly lower enhancement in toughness than H-fiber. As the maximum size of coarse aggregate decreased from 19 to 5 mm, the tensile strength and toughness of FRCs with T-fibers noticeably increased at both static and high strain rates.

  10. Tensile testing

    CERN Document Server

    2004-01-01

    A complete guide to the uniaxial tensile test, the cornerstone test for determining the mechanical properties of materials: Learn ways to predict material behavior through tensile testing. Learn how to test metals, alloys, composites, ceramics, and plastics to determine strength, ductility and elastic/plastic deformation. A must for laboratory managers, technicians, materials and design engineers, and students involved with uniaxial tensile testing. Tensile Testing , Second Edition begins with an introduction and overview of the test, with clear explanations of how materials properties are determined from test results. Subsequent sections illustrate how knowledge gained through tensile tests, such as tension properties to predict the behavior (including strength, ductility, elastic or plastic deformation, tensile and yield strengths) have resulted in improvements in materals applications. The Second Edition is completely revised and updated. It includes expanded coverage throughout the volume on a variety of ...

  11. Tensile behavior of laser treated Fe-Si-B metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Sameehan S.; Samimi, Peyman; Ghamarian, Iman; Katakam, Shravana; Collins, Peter C.; Dahotre, Narendra B., E-mail: narendra.dahotre@unt.edu [Department of Materials Science and Engineering, University of North Texas, 1150 Union Circle 305310, Denton, Texas 76203-5017 (United States)

    2015-10-28

    Fe-Si-B metallic glass foils were treated with a linear laser track using a continuous wave Nd-YAG laser and its effect on the overall tensile behavior was investigated. Microstructure and phase evolutions were evaluated using X-ray diffraction, resistivity measurements, and transmission electron microscopy. Crystallization fraction was estimated via the differential scanning calorimetry technique. Metallic glass foils treated with the lower laser fluences (<0.49 J/mm{sup 2}) experienced structural relaxation, whereas higher laser fluences led to crystallization within the laser treated region. The overall tensile behavior was least impacted by structural relaxation, whereas crystallization severely reduced the ultimate tensile strength of the laser treated metallic glass foils.

  12. Dynamic tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix composites

    International Nuclear Information System (INIS)

    Chen Xuan; Li Yulong

    2011-01-01

    Graphical abstract: The dynamic tensile behavior of 2D C/SiC composites was experimentally investigated by means of SHTB. Both the fracture surface and bundle fracture surfaces of composites were observed. The strain rate sensitivity of in-bundle interface was concluded as the dominant contributor to the strain rate sensitivity of the tensile strength. Highlights: → The tensile strength increases with strain rate. → The tensile failure strain remains independent of strain rate. → Macro-structural morphology reveals rough fracture surface under dynamic loading. → SEM morphology reveals integrated bundle pull-out under dynamic loading. → Strain rate sensitivity of in-bundle interface leads to that of the tensile strength. - Abstract: An investigation has been undertaken to determine the dynamic and quasi-static tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix (2D-C/SiC) composites by means of the split Hopkinson tension bar and an electronic universal test machine respectively. The results indicate that the tensile strength of 2D C/SiC composites is increased at high strain rate. Furthermore, coated specimens show not only a 15% improvement in tensile strength but heightened strain rate sensitivity compared with uncoated ones. It is also shown that the tensile failure strain is strain rate insensitive and remains around 0.4%. Optical macrograph of failed specimens under dynamic loading revealed jagged fracture surfaces characterized by delamination and crack deviation, together with obvious fiber pull-out/splitting, in contrast with the smooth fracture surfaces under quasi-static loading. Scanning electron microscopy micrograph of fracture surface under dynamic loading clearly displayed integrated bundle pull-out which implies suppressed in-bundle debonding and enhanced in-bundle interfacial strengthening, in contrast with extensive in-bundle debonding under quasi-static loading. Thus we conclude that, with 2D C

  13. Tensile and compressive behavior of Borsic/aluminum

    Science.gov (United States)

    Herakovich, C. T.; Davis, J. G., Jr.; Viswanathan, C. N.

    1977-01-01

    The results of an experimental investigation of the mechanical behavior of Borsic/aluminum are presented. Composite laminates were tested in tension and compression for monotonically increasing load and also for variable loading cycles in which the maximum load was increased in each successive cycle. It is shown that significant strain-hardening, and corresponding increase in yield stress, is exhibited by the metal matrix laminates. For matrix dominated laminates, the current yield stress is essentially identical to the previous maximum stress, and unloading is essentially linear with large permanent strains after unloading. For laminates with fiber dominated behavior, the yield stress increases with increase in the previous maximum stress, but the increase in yield stress does not keep pace with the previous maximum stress. These fiber dominated laminates exhibit smaller nonlinear strains, reversed nonlinear behavior during unloading, and smaller permanent strains after unloading. Compression results from sandwich beams and flat coupons are shown to differ considerably. Results from beam specimens tend to exhibit higher values for modulus, yield stress, and strength.

  14. A modified Johnson–Cook model of dynamic tensile behaviors for 7075-T6 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ding-Ni, E-mail: siping4840@126.com [The College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234 (China); Shangguan, Qian-Qian [The College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234 (China); Xie, Can-Jun [Commercial Aircraft Corporation of China, Ltd., Shanghai 200120 (China); Liu, Fu [Shanghai Aircraft Design and Research Institute of COMAC, Shanghai 201210 (China)

    2015-01-15

    Highlights: • The dynamic mechanical behaviors at various strain rates were measured. • The strain rate hardening effect of 7075-T6 aluminum alloy is significant. • A new Johnson–Cook constitutive model of 7075-T6 aluminum alloy was obtained. • Numerical simulations of tensile tests at different rates were conducted. • Accuracy of the modified Johnson–Cook constitutive equation was proved. - Abstract: The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson tensile bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.

  15. Effect of cryogenic treatment on tensile behavior of case carburized steel-815M17

    International Nuclear Information System (INIS)

    Bensely, A.; Senthilkumar, D.; Mohan Lal, D.; Nagarajan, G.; Rajadurai, A.

    2007-01-01

    The crown wheel and pinion represent the most highly stressed parts of a heavy vehicle; these are typically made of 815M17 steel. The reasons for the frequent failure of these components are due to tooth bending impact, wear and fatigue. The modern processes employed to produce these as high, durable components include cryogenic treatment as well as conventional heat treatment. It helps to convert retained austenite into martensite as well as promote carbide precipitation. This paper deals with the influence of cryogenic treatment on the tensile behavior of case carburized steel 815M17. The impetus for studying the tensile properties of gear steels is to ensure that steels used in gears have sufficient tensile strength to prevent failure when gears are subjected to tensile or fatigue loads, and to provide basic design information on the strength of 815M17 steel. A comparative study on the effects of deep cryogenic treatment (DCT), shallow cryogenic treatment (SCT) and conventional heat treatment (CHT) was made by means of tension testing. This test was conducted as per ASTM standard designation E 8M. The present results confirm that the tensile behavior is marginally reduced after cryogenic treatment (i.e. both shallow and deep cryogenic treatment) for 815M17 when compared with conventional heat treatment. Scanning electron microscopic (SEM) analysis of the fracture surface indicates the presence of dimples and flat fracture regions are more common in SCT specimens than for CHT and DCT-processed material

  16. A modified Johnson–Cook model of dynamic tensile behaviors for 7075-T6 aluminum alloy

    International Nuclear Information System (INIS)

    Zhang, Ding-Ni; Shangguan, Qian-Qian; Xie, Can-Jun; Liu, Fu

    2015-01-01

    Highlights: • The dynamic mechanical behaviors at various strain rates were measured. • The strain rate hardening effect of 7075-T6 aluminum alloy is significant. • A new Johnson–Cook constitutive model of 7075-T6 aluminum alloy was obtained. • Numerical simulations of tensile tests at different rates were conducted. • Accuracy of the modified Johnson–Cook constitutive equation was proved. - Abstract: The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson tensile bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved

  17. Tensile Behavior Analysis on Different Structures of 3D Glass Woven Perform for Fibre Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Mazhar Hussain Peerzada

    2013-01-01

    Full Text Available Three common 3D (Three Dimensional Glass woven structures were studied to analyze the tensile behavior. Each type of strand (Warp, weft and binder of 3D woven structure was studied in detail. Crimp percentage of those strands was measured by crimp meter. Standard size samples of each 3D woven structure were cut in warp and weft direction and were stretched by Instron Tensile testing computerized machine. Results reveal that hybrid possesses lowest crimp in core strands and higher strength in warp as well as weft direction. Layer to layer woven structure appeared with lower strength and higher strain value due to highest crimp percentage in core strands.

  18. Effects of annealing on tensile property and corrosion behavior of Ti-Al-Zr alloy

    International Nuclear Information System (INIS)

    Kim, Tae-Kyu; Choi, Byung-Seon; Jeong, Yong-Hwan; Lee, Doo-Jeong; Chang, Moon-Hee

    2002-01-01

    The effects of annealing on the tensile property and corrosion behavior of Ti-Al-Zr alloy were evaluated. The annealing in the temperature range from 500 to 800 deg. C for 1 h induced the growth of the grain and the precipitate sizes. The results of tensile tests at room temperature showed that the strengths and the ductility were almost independent of the annealing temperature. However, the results of corrosion test in an ammonia aqueous solution of pH 9.98 at 360 deg. C showed that the corrosion resistance depended on the annealing temperature, and the corrosion rate was accelerated with increasing annealing temperature. Hydrogen contents absorbed during the corrosion test of 220 days also increased with the annealing temperature. It could be attributed to the growth of Fe-rich precipitates by annealing. It is thus suggested that the lower annealing temperatures provide the better corrosion properties without degrading the tensile properties

  19. Defects annihilation behavior of neutron-irradiated SiC ceramics densified by liquid-phase-assisted method after post-irradiation annealing

    Directory of Open Access Journals (Sweden)

    Mohd Idzat Idris

    2016-12-01

    Full Text Available Numerous studies on the recovery behavior of neutron-irradiated high-purity SiC have shown that most of the defects present in it are annihilated by post-irradiation annealing, if the neutron fluence is less than 1×1026 n/m2 (>0.1MeV and the irradiation is performed at temperatures lower than 973K. However, the recovery behavior of SiC fabricated by the nanoinfiltrated and transient eutectic phase (NITE process is not well understood. In this study, the effects of secondary phases on the irradiation-related swelling and recovery behavior of monolithic NITE-SiC after post-irradiation annealing were studied. The NITE-SiC specimens were irradiated in the BR2 reactor at fluences of up to 2.0–2.5×1024 n/m2 (E>0.1MeV at 333–363K. This resulted in the specimens swelling up ∼1.3%, which is 0.1% higher than the increase seen in concurrently irradiated high-purity SiC. The recovery behaviors of the specimens after post-irradiation thermal annealing were examined using a precision dilatometer; the specimens were heated at temperatures of up to 1673K using a step-heating method. The recovery curves were analyzed using a first-order model, and the rate constants for each annealing step were obtained to determine the activation energy for volume recovery. The NITE-A specimen (containing 12 wt% sintering additives recovered completely after annealing at ∼1573K; however, it shrank because of the volatilization of the oxide phases at 1673K. The NITE-B specimen (containing 18wt% sintering additives did not recover fully, since the secondary phase (YAG was crystallized during the annealing process. The recovery mechanism of NITE-A SiC was based on the recombination of the C and Si Frenkel pairs, which were very closely sited or only slightly separated at temperatures lower than 1223K, as well as the recombination of the slightly separated C Frenkel pairs and the migration of C and Si interstitials at temperatures of 1223–1573K. That is to say, the

  20. A Study on Mechanical behavior of Tensile Specimen Fabricated by Laser Cutting

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Y. G.; Kim, G. S.; Baik, S. J.; Baek, S. Y. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The mechanical testing data are required for the assessment of dry storage of the spent nuclear fuel. Laser cutting system could be useful tools for material processing such as cutting in radioactive environment due to non-contact nature, ease in handling and the laser cutting process is most advantageous, offering the narrow kerf width and heat affected zone by using small beam spot diameter. The feasibility of the laser cutting system was demonstrated for the fabrication of various types of the unirradiated cladding with and without oxide layer on the specimens. In the present study, the dimensional measurement and tensile test were conducted to investigate the mechanical behavior of the axial tensile test specimens depending on the material processing methods in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. Laser cutting system was used to fabricate the tensile test specimens, and the mechanical behavior was investigated using the dimensional measurement and tensile test. It was shown that the laser beam machining could be a useful tool to fabricate the specimens and this technique will be developed for the fabrication of various types of irradiated specimens in a hotcell.

  1. Mechanical Behavior of Red Sandstone under Incremental Uniaxial Cyclical Compressive and Tensile Loading

    Directory of Open Access Journals (Sweden)

    Baoyun Zhao

    2017-01-01

    Full Text Available Uniaxial experiments were carried out on red sandstone specimens to investigate their short-term and creep mechanical behavior under incremental cyclic compressive and tensile loading. First, based on the results of short-term uniaxial incremental cyclic compressive and tensile loading experiments, deformation characteristics and energy dissipation were analyzed. The results show that the stress-strain curve of red sandstone has an obvious memory effect in the compressive and tensile loading stages. The strains at peak stresses and residual strains increase with the cycle number. Energy dissipation, defined as the area of the hysteresis loop in the stress-strain curves, increases nearly in a power function with the cycle number. Creep test of the red sandstone was also conducted. Results show that the creep curve under each compressive or tensile stress level can be divided into decay and steady stages, which cannot be described by the conventional Burgers model. Therefore, an improved Burgers creep model of rock material is constructed through viscoplastic mechanics, which agrees very well with the experimental results and can describe the creep behavior of red sandstone better than the Burgers creep model.

  2. A Study on Mechanical behavior of Tensile Specimen Fabricated by Laser Cutting

    International Nuclear Information System (INIS)

    Jin, Y. G.; Kim, G. S.; Baik, S. J.; Baek, S. Y.

    2016-01-01

    The mechanical testing data are required for the assessment of dry storage of the spent nuclear fuel. Laser cutting system could be useful tools for material processing such as cutting in radioactive environment due to non-contact nature, ease in handling and the laser cutting process is most advantageous, offering the narrow kerf width and heat affected zone by using small beam spot diameter. The feasibility of the laser cutting system was demonstrated for the fabrication of various types of the unirradiated cladding with and without oxide layer on the specimens. In the present study, the dimensional measurement and tensile test were conducted to investigate the mechanical behavior of the axial tensile test specimens depending on the material processing methods in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. Laser cutting system was used to fabricate the tensile test specimens, and the mechanical behavior was investigated using the dimensional measurement and tensile test. It was shown that the laser beam machining could be a useful tool to fabricate the specimens and this technique will be developed for the fabrication of various types of irradiated specimens in a hotcell

  3. Acute postirradiation nephropathy

    International Nuclear Information System (INIS)

    Trojanowski, Z.

    1982-01-01

    The pathogenesis, morphological and clinical signs of acute postirradiation nephropathy are described with particular attention paid to the relationship between the clinical signs of renal involvement and the dose of radiation. (author)

  4. Squeeze casting of aluminum alloy A380: Microstructure and tensile behavior

    Directory of Open Access Journals (Sweden)

    Li Fang

    2015-09-01

    Full Text Available A380 alloy with a relatively thick cross-section of 25 mm was squeeze cast using a hydraulic press with an applied pressure of 90 MPa. Microstructure and tensile properties of the squeeze cast A380 were characterized and evaluated in comparison with the die cast counterpart. Results show that the squeeze cast A380 possesses a porosity level much lower than the die cast alloy, which is disclosed by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength (UTS: 215.9 MPa and elongation (Ef: 5.4%, for the squeeze cast samples over those of the conventional high-pressure die cast part (UTS: 173.7 MPa, Ef: 1.0%. The analysis of tensile behavior shows that the squeeze cast A380 exhibits a high tensile toughness (8.5 MJ·m-3 and resilience (179.3 kJ·m-3 compared with the die cast alloy (toughness: 1.4 MJ·m-3, resilience: 140.6 kJ·m-3, despite that, during the onset of plastic deformation, the strain-hardening rate of the die cast specimen is higher than that of the squeeze cast specimens. The microstructure analyzed by the scanning electron microscopy (SEM shows that both the squeeze and die cast specimens contain the primary α-Al, Al2Cu, Al5FeSi phase and the eutectic Si phase. But, the Al2Cu phase present in the squeeze cast alloy is relatively large in size and quantity. The SEM fractography evidently reveals the ductile fracture features of the squeeze cast A380 alloy.

  5. Characterization of Tensile Mechanical Behavior of MSCs/PLCL Hybrid Layered Sheet

    Directory of Open Access Journals (Sweden)

    Azizah Intan Pangesty

    2016-06-01

    Full Text Available A layered construct was developed by combining a porous polymer sheet and a cell sheet as a tissue engineered vascular patch. The primary objective of this study is to investigate the influence of mesenchymal stem cells (MSCs sheet on the tensile mechanical properties of porous poly-(l-lactide-co-ε-caprolactone (PLCL sheet. The porous PLCL sheet was fabricated by the solid-liquid phase separation method and the following freeze-drying method. The MSCs sheet, prepared by the temperature-responsive dish, was then layered on the top of the PLCL sheet and cultured for 2 weeks. During the in vitro study, cellular properties such as cell infiltration, spreading and proliferation were evaluated. Tensile test of the layered construct was performed periodically to characterize the tensile mechanical behavior. The tensile properties were then correlated with the cellular properties to understand the effect of MSCs sheet on the variation of the mechanical behavior during the in vitro study. It was found that MSCs from the cell sheet were able to migrate into the PLCL sheet and actively proliferated into the porous structure then formed a new layer of MSCs on the opposite surface of the PLCL sheet. Mechanical evaluation revealed that the PLCL sheet with MSCs showed enhancement of tensile strength and strain energy density at the first week of culture which is characterized as the effect of MSCs proliferation and its infiltration into the porous structure of the PLCL sheet. New technique was presented to develop tissue engineered patch by combining MSCs sheet and porous PLCL sheet, and it is expected that the layered patch may prolong biomechanical stability when implanted in vivo.

  6. Influence of dynamic strain aging on tensile deformation behavior of alloy 617

    Energy Technology Data Exchange (ETDEWEB)

    Ekaputra, I. M. W. [Pukyong National University, Busan (Korea, Republic of); Kim, Woo Gon; Park, Jae Young; Kim, Seon Jin; Kim, Eung Seon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    To investigate the dynamic strain aging (DSA) behavior of Alloy 617, high-temperature tensile tests were carried out with strain rates variations of 10{sup -}3{sup /}s, 10{sup -4}/s, and 10{sup -5}/s from 24°C to 950°C. Five flow relationships, Hollomon, Ludwik, Swift, Ludwigson, and Voce, were applied to describe the tensile true stress–strain curves, and the DSA region was defined. In describing the tensile curves, Ludwigson's equation was superior to the other equations, and the DSA region was adequately defined by this equation as plateaus at intermediate temperatures from 200°C to 700°C. It was identified that Alloy 617 is dominated by three types of serrations, known as Types D, A+B, and C. The activation energy values for each serration type were obtained by the Arrhenius equation. By using the obtained activation energy values, the serrated yielding map and the DSA mechanism were drawn and manifested. In addition, the relationship between the tensile strength and strain rate at higher temperatures above 700°C was found to be closely related to the amounts of slip lines. In the scanning electron microscope (SEM) fractographs, there was a significant difference at the low, intermediate, and high temperatures, but almost the same to the three strain rates.

  7. Tensile fracture behaviors of T-ZnOw/polyamide 6 composites

    International Nuclear Information System (INIS)

    Shi Jing; Wang Yong; Liu Li; Bai Hongwei; Wu Jun; Jiang Chongxi; Zhou, Zuowan

    2009-01-01

    As a part of serial work about the application of tetra-needle-shaped zinc oxide whisker (T-ZnOw) in polymer composites, this work is focused on the crystallization and tensile fracture behaviors of T-ZnOw/polyamide 6 (T-ZnOw/PA6) composites. Our results show that the addition of T-ZnOw improves the composites tensile strength greatly. For virgin PA6, the stress-strain curve exhibits double-yielding phenomenon. Surface modified T-ZnOw reinforced PA6 composites exhibit higher yield stress and smaller strain-to-fracture compared with virgin PA6. The morphologies of tensile-fractured surfaces show that, addition of T-ZnOw changes the fracture mode from crazing-tearing/brittle fracture mode of virgin PA6 into fibrillation/brittle fracture mode of PA6 composites. Especially, the fracture process of T-ZnOw in composites during the tensile test has been characterized by scanning electronic microscope (SEM) and the corresponding reinforcement mechanism has been discussed.

  8. Influence of dynamic strain aging on tensile deformation behavior of alloy 617

    International Nuclear Information System (INIS)

    Ekaputra, I. M. W.; Kim, Woo Gon; Park, Jae Young; Kim, Seon Jin; Kim, Eung Seon

    2016-01-01

    To investigate the dynamic strain aging (DSA) behavior of Alloy 617, high-temperature tensile tests were carried out with strain rates variations of 10"-3"/s, 10"-"4/s, and 10"-"5/s from 24°C to 950°C. Five flow relationships, Hollomon, Ludwik, Swift, Ludwigson, and Voce, were applied to describe the tensile true stress–strain curves, and the DSA region was defined. In describing the tensile curves, Ludwigson's equation was superior to the other equations, and the DSA region was adequately defined by this equation as plateaus at intermediate temperatures from 200°C to 700°C. It was identified that Alloy 617 is dominated by three types of serrations, known as Types D, A+B, and C. The activation energy values for each serration type were obtained by the Arrhenius equation. By using the obtained activation energy values, the serrated yielding map and the DSA mechanism were drawn and manifested. In addition, the relationship between the tensile strength and strain rate at higher temperatures above 700°C was found to be closely related to the amounts of slip lines. In the scanning electron microscope (SEM) fractographs, there was a significant difference at the low, intermediate, and high temperatures, but almost the same to the three strain rates

  9. Analysis of Deformation and Failure Behaviors of TIG Welded Dissimilar Metal Joints Using Miniature Tensile Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ji-Hwan; Jahanzeb, Nabeel; Kim, Min-Seong; Hwang, Ji-Hyun; Choi, Shi-Hoon [Sunchon National University, Suncheon (Korea, Republic of)

    2017-02-15

    The deformation and failure behaviors of dissimilar metal joints between SS400 steel and STS316L steel were investigated. The dissimilar metal joints were fabricated using the tungsten inert gas (TIG) welding process with STS309 steel as a filler metal. The microstructures of the dissimilar metal joints were investigated using an optical microscope and EBSD technique. The mechanical properties of the base metal (BM), heat affected zone (HAZ) and weld metal (WM) were measured using a micro-hardness and micro-tension tester combined with the digital image correlation (DIC) technique. The HAZ of the STS316L steel exhibited the highest micro-hardness value, and yield/tensile strengths, while the BM of the SS440 steel exhibited the lowest micro-hardness value and yield /tensile strengths. The grain size refinement in the HAZ of SS400 steel induced an enhancement of micro-hardness value and yield/tensile strengths compared to the BM of the SS400 steel. The WM, which consists of primary δ-ferrite and a matrix of austenite phase, exhibited relatively a high micro-hardness value, yield /tensile strengths and elongation compared to the BM and HAZ of the SS400 steel.

  10. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.M.A., E-mail: madel@uqac.ca [Center for Advanced Materials, Qatar University, Doha (Qatar); Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez Canal University, Box 43721, Suez (Egypt); Samuel, F.H. [Université du Québec à Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Al Kahtani, Saleh [Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Salman bin Abdulaziz University, Al Kharj (Saudi Arabia)

    2013-08-10

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si){sub 3}(Zr, Ti), Al{sub 3}CuNi and Al{sub 9}NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied.

  11. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    International Nuclear Information System (INIS)

    Mohamed, A.M.A.; Samuel, F.H.; Al Kahtani, Saleh

    2013-01-01

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si) 3 (Zr, Ti), Al 3 CuNi and Al 9 NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied

  12. Tensile Flow Behavior of Tungsten Heavy Alloys Produced by CIPing and Gelcasting Routes

    Science.gov (United States)

    Panchal, Ashutosh; Ravi Kiran, U.; Nandy, T. K.; Singh, A. K.

    2018-06-01

    Present work describes the flow behavior of tungsten heavy alloys with nominal compositions 90W-7Ni-3Fe, 93W-4.9Ni-2.1Fe, and 95W-3.5Ni-1.5Fe (wt pct) produced by CIPing and gelcasting routes. The overall microstructural features of gelcasting are finer than those of CIPing alloys. Both the grain size of W and corresponding contiguity values increase with increase in W content in the present alloys. The volume fraction of matrix phase decreases with increase in W content in both the alloys. The lattice parameter values of the matrix phase also increase with increase in W content. The yield strength ( σ YS) continuously increases with increase in W content in both the alloys. The σ YS values of CIPing alloys are marginally higher than those of gelcasting at constant W. The ultimate tensile strength ( σ UTS) and elongation values are maximum at intermediate W content. Present alloys exhibit two slopes in true stress-true plastic strain curves in low and high strain regimes and follow a characteristic Ludwigson relation. The two slopes are associated with two deformation mechanisms that are occurring during tensile deformation. The overall nature of differential curves of all the alloys is different and these curves contain three distinctive stages of work hardening (I, II, and III). This suggests varying deformation mechanisms during tensile testing due to different volume fractions of constituent phases. The slip is the predominant deformation mechanism of the present alloys during tensile testing.

  13. Tensile properties and flow behavior analysis of modified 9Cr–1Mo steel clad tube material

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Kanwarjeet, E-mail: kanwar722@yahoo.com; Latha, S.; Nandagopal, M.; Mathew, M.D.; Laha, K.; Jayakumar, T.

    2014-11-15

    The tensile properties and flow behavior of modified 9Cr–1Mo steel clad tube have been investigated in the framework of various constitutive equations for a wide range of temperatures (300–923 K) and strain rates (3 × 10{sup −3} s{sup −1}, 3 × 10{sup −4} s{sup −1} and 3 × 10{sup −5} s{sup −1}). The tensile flow behavior of modified 9Cr–1Mo steel clad tube was most accurately described by Voce equation. The variation of instantaneous work hardening rate (θ = dσ/dε) and σθ with stress (σ) indicated two stage behavior characterized by rapid decrease at low stresses (transient stage) followed by a gradual decrease in high stresses (Stage III). The variation of work hardening parameters and work hardening rate in terms of θ vs. σ and σθ vs. σ with temperature exhibited three distinct regimes. Rapid decrease in flow stress and work hardening parameters and rapid shift of θ vs. σ and σθ vs. σ towards low stresses with increase in temperature indicated dynamic recovery at high temperatures. Tensile properties of the material have been best predicted from Voce equation.

  14. Tensile properties and flow behavior analysis of modified 9Cr-1Mo steel clad tube material

    Science.gov (United States)

    Singh, Kanwarjeet; Latha, S.; Nandagopal, M.; Mathew, M. D.; Laha, K.; Jayakumar, T.

    2014-11-01

    The tensile properties and flow behavior of modified 9Cr-1Mo steel clad tube have been investigated in the framework of various constitutive equations for a wide range of temperatures (300-923 K) and strain rates (3 × 10-3 s-1, 3 × 10-4 s-1 and 3 × 10-5 s-1). The tensile flow behavior of modified 9Cr-1Mo steel clad tube was most accurately described by Voce equation. The variation of instantaneous work hardening rate (θ = dσ/dε) and σθ with stress (σ) indicated two stage behavior characterized by rapid decrease at low stresses (transient stage) followed by a gradual decrease in high stresses (Stage III). The variation of work hardening parameters and work hardening rate in terms of θ vs. σ and σθ vs. σ with temperature exhibited three distinct regimes. Rapid decrease in flow stress and work hardening parameters and rapid shift of θ vs. σ and σθ vs. σ towards low stresses with increase in temperature indicated dynamic recovery at high temperatures. Tensile properties of the material have been best predicted from Voce equation.

  15. Tensile properties and flow behavior analysis of modified 9Cr–1Mo steel clad tube material

    International Nuclear Information System (INIS)

    Singh, Kanwarjeet; Latha, S.; Nandagopal, M.; Mathew, M.D.; Laha, K.; Jayakumar, T.

    2014-01-01

    The tensile properties and flow behavior of modified 9Cr–1Mo steel clad tube have been investigated in the framework of various constitutive equations for a wide range of temperatures (300–923 K) and strain rates (3 × 10 −3 s −1 , 3 × 10 −4 s −1 and 3 × 10 −5 s −1 ). The tensile flow behavior of modified 9Cr–1Mo steel clad tube was most accurately described by Voce equation. The variation of instantaneous work hardening rate (θ = dσ/dε) and σθ with stress (σ) indicated two stage behavior characterized by rapid decrease at low stresses (transient stage) followed by a gradual decrease in high stresses (Stage III). The variation of work hardening parameters and work hardening rate in terms of θ vs. σ and σθ vs. σ with temperature exhibited three distinct regimes. Rapid decrease in flow stress and work hardening parameters and rapid shift of θ vs. σ and σθ vs. σ towards low stresses with increase in temperature indicated dynamic recovery at high temperatures. Tensile properties of the material have been best predicted from Voce equation

  16. Microstructure and Tensile Behavior of Laser Arc Hybrid Welded Dissimilar Al and Ti Alloys

    Directory of Open Access Journals (Sweden)

    Ming Gao

    2014-02-01

    Full Text Available Fiber laser-cold metal transfer arc hybrid welding was developed to welding-braze dissimilar Al and Ti alloys in butt configuration. Microstructure, interface properties, tensile behavior, and their relationships were investigated in detail. The results show the cross-weld tensile strength of the joints is up to 213 MPa, 95.5% of same Al weld. The optimal range of heat input for accepted joints was obtained as 83–98 J·mm−1. Within this range, the joint is stronger than 200 MPa and fractures in weld metal, or else, it becomes weaker and fractures at the intermetallic compounds (IMCs layer. The IMCs layer of an accepted joint is usually thin and continuous, which is about 1μm-thick and only consists of TiAl2 due to fast solidification rate. However, the IMCs layer at the top corner of fusion zone/Ti substrate is easily thickened with increasing heat input. This thickened IMCs layer consists of a wide TiAl3 layer close to FZ and a thin TiAl2 layer close to Ti substrate. Furthermore, both bead shape formation and interface growth were discussed by laser-arc interaction and melt flow. Tensile behavior was summarized by interface properties.

  17. A Study of Tensile Flow and Work-Hardening Behavior of Alloy 617

    Science.gov (United States)

    Singh, Aditya Narayan; Moitra, A.; Bhaskar, Pragna; Dasgupta, Arup; Sasikala, G.; Bhaduri, A. K.

    2018-04-01

    The simple power relationship σ = Κɛ p n satisfactorily expresses the tensile flow behavior of many metals and alloys in their uniform plastic strain regime. However, many FCC materials with low stacking fault energy have opposed such power law relationship. Alloy 617, an age-hardenable Ni-based superalloy is also observed not to obey the simple power law relationship neither in its solution-treated nor in its aged conditions. Various flow relationships were used to obtain the best fit for the tensile data, and different relationships were identified for the different aged conditions. The work-hardening rate (θ) demonstrates three distinct regions for all aged conditions, and there is an obvious change in the trend of θ versus σ. In the initial portion, θ decreases rapidly followed by a gradual increase in the second stage and again a decrease in its third stage is perceived in the Alloy 617. These three-stage characteristics are attributed to a commonly known precipitate, γ': Ni3(Ti, Al) which evolves during aging treatment and well recognized under transmission electron microscopy (TEM) observation. TEM results also reveal a slight degree of coarsening in γ' over aging. The tensile flow and the work-hardening behavior are well correlated with other microstructural evolution during the aging treatments.

  18. The High Temperature Tensile and Creep Behaviors of High Entropy Superalloy.

    Science.gov (United States)

    Tsao, Te-Kang; Yeh, An-Chou; Kuo, Chen-Ming; Kakehi, Koji; Murakami, Hideyuki; Yeh, Jien-Wei; Jian, Sheng-Rui

    2017-10-04

    This article presents the high temperature tensile and creep behaviors of a novel high entropy alloy (HEA). The microstructure of this HEA resembles that of advanced superalloys with a high entropy FCC matrix and L1 2 ordered precipitates, so it is also named as "high entropy superalloy (HESA)". The tensile yield strengths of HESA surpass those of the reported HEAs from room temperature to elevated temperatures; furthermore, its creep resistance at 982 °C can be compared to those of some Ni-based superalloys. Analysis on experimental results indicate that HESA could be strengthened by the low stacking-fault energy of the matrix, high anti-phase boundary energy of the strengthening precipitate, and thermally stable microstructure. Positive misfit between FCC matrix and precipitate has yielded parallel raft microstructure during creep at 982 °C, and the creep curves of HESA were dominated by tertiary creep behavior. To the best of authors' knowledge, this article is the first to present the elevated temperature tensile creep study on full scale specimens of a high entropy alloy, and the potential of HESA for high temperature structural application is discussed.

  19. Characterization and modeling of tensile behavior of ceramic woven fabric composites

    Science.gov (United States)

    Kuo, Wen-Shyong; Chen, Wennei Y.; Parvizi-Majidi, Azar; Chou, Tsu-Wei

    1991-01-01

    This paper examines the tensile behavior of SiC/SiC fabric composites. In the characterization effort, the stress-strain relation and damage evolution are studied with a series of loading and unloading tensile test experiments. The stress-strain relation is linear in response to the initial loading and becomes nonlinear when loading exceeds the proportional limit. Transverse cracking has been observed to be a dominant damage mode governing the nonlinear deformation. The damage is initiated at the inter-tow pores where fiber yarns cross over each other. In the modeling work, the analysis is based upon a fiber bundle model, in which fiber undulation in the warp and fill directions and gaps among fiber yarns have been taken into account. Two limiting cases of fabric stacking arrangements are studied. Closed form solutions are obtained for the composite stiffness and Poisson's ratio. Transverse cracking in the composite is discussed by applying a constant failure strain criterion.

  20. Effect of ageing on tensile behavior of ultrafine grained Al 6061 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Rao, P. Nageswara [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India); Singh, Dharmendra [Department of Mechanical Engineering, Government Engineering College, Bikaner 304001 (India); Brokmeier, Heinz-Günter [Helmholtz Zentrum Geesthacht, Max Planck Straße 1, Geb 33, D-21502 Geesthacht (Germany); Jayaganthan, R., E-mail: rjayafmt@iitr.ernet.in [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India)

    2015-08-12

    In the present investigation, the ageing behavior of ultrafine grained (UFG) Al 6061 alloy, processed through multi-directional forging (MDF) at cryogenic temperature was investigated. The evolution of microstructure was investigated through transmission electron microscopy and electron back scattered diffraction technique. The results indicate that homogeneous microstructure with an ultrafine grain morphology (average size 250 nm) was achieved through cryogenic forging of the alloy subjected to prior solutionising treatment. Tensile testing at room temperature revealed that MDFed material after ageing led to significant improvement in work hardening and its tensile ductility. Strengthening of the matrix through various mechanisms has been quantified with the existing models to estimate the yield strength of the as forged and peak aged material. The precipitation hardening response in UFG material is found to be 35% lower than that of the coarse grained material as observed in the present work.

  1. Tensile behavior of nickel-base single-crystal superalloy DD6

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Xinhong, E-mail: xiongxh@whut.edu.cn [School of Logistics Engineering, Wuhan University of Technology, Wuhan 430063 (China); Quan, Dunmiao; Dai, Pengdan; Wang, Zhiping [School of Logistics Engineering, Wuhan University of Technology, Wuhan 430063 (China); Zhang, Qiaoxin [School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070 (China); Yue, Zhufeng [School of Mechanics Civil Engineering and Architecture, Northwestern Polytechnical University, Xi' an 710072 (China)

    2015-06-11

    Tensile behavior of the nickel-base single-crystal superalloy DD6 was studied from room temperature to 1020 °C. The plate specimens were along [001] orientation parallel to the loading axis in tension. The microstructures on the surface and fracture morphology were investigated after tensile test to rupture by scanning electron microscopy (SEM). The results of the present investigation indicate that the yield strength at 650 °C is superior to that at room temperature, 850 °C and 1020 °C. Low ductility and serrated flow in stress–strain curves were also observed at 650 °C. The microstructures on the surface of the plate specimens and fracture morphology observation indicated that localized slip which resulted in glide plane decohesion caused the low ductility of DD6 alloy.

  2. Effects of temperature and strain rate on the tensile behaviors of SIMP steel in static lead bismuth eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian, E-mail: jliu12b@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Yan, Wei [Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Sha, Wei [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, Belfast, BT9 5AG (United Kingdom); Wang, Wei; Shan, Yiyin [Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 (China)

    2016-05-15

    In order to assess the susceptibility of candidate structural materials to liquid metal embrittlement, this work investigated the tensile behaviors of ferritic-martensitic steel in static lead bismuth eutectic (LBE). The tensile tests were carried out in static lead bismuth eutectic under different temperatures and strain rates. Pronounced liquid metal embrittlement phenomenon is observed between 200 °C and 450 °C. Total elongation is reduced greatly due to the liquid metal embrittlement in LBE environment. The range of ductility trough is larger under slow strain rate tensile (SSRT) test. - Highlights: • The tensile behaviors of SIMP steel in LBE are investigated for the first time. • The SIMP is susceptible to LME at different strain rates and temperatures. • The total elongation is reduced greatly. • The ductility trough is wider under SSRT. • The tensile specimens rupture in brittle manner without obvious necking.

  3. Effects of temperature and strain rate on the tensile behaviors of SIMP steel in static lead bismuth eutectic

    International Nuclear Information System (INIS)

    Liu, Jian; Yan, Wei; Sha, Wei; Wang, Wei; Shan, Yiyin; Yang, Ke

    2016-01-01

    In order to assess the susceptibility of candidate structural materials to liquid metal embrittlement, this work investigated the tensile behaviors of ferritic-martensitic steel in static lead bismuth eutectic (LBE). The tensile tests were carried out in static lead bismuth eutectic under different temperatures and strain rates. Pronounced liquid metal embrittlement phenomenon is observed between 200 °C and 450 °C. Total elongation is reduced greatly due to the liquid metal embrittlement in LBE environment. The range of ductility trough is larger under slow strain rate tensile (SSRT) test. - Highlights: • The tensile behaviors of SIMP steel in LBE are investigated for the first time. • The SIMP is susceptible to LME at different strain rates and temperatures. • The total elongation is reduced greatly. • The ductility trough is wider under SSRT. • The tensile specimens rupture in brittle manner without obvious necking.

  4. Tensile behavior change depending on the microstructure of a Fe-Cu alloy produced from rapidly solidified powder

    International Nuclear Information System (INIS)

    Kakisawa, Hideki; Minagawa, Kazumi; Halada, Kohmei

    2003-01-01

    The relationship between consolidating temperature and the tensile behavior of iron alloy produced from Fe-Cu rapidly solidified powder is investigated. Fe-Cu powder fabricated by high-pressure water atomization was consolidated by heavy rolling at 873-1273 K. Microstructural changes were observed and tensile behavior was examined. Tensile behavior varies as the consolidating temperature changes, and these temperature-dependent differences depend on the morphology of the microstructure on the order of micrometers. The sample consolidated at 873 K shows a good strength/elongation balance because the powder microstructure and primary powder boundaries are maintained. The samples consolidated at the higher temperatures have a microstructure of recrystallized grains, and these recrystallized samples show the conventional relationship between tensile behavior and grain size in ordinal bulk materials

  5. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    International Nuclear Information System (INIS)

    Shibata, K.; Fujii, H.

    2004-01-01

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation

  6. Effect of Preparation Methods on Crystallization Behavior and Tensile Strength of Poly(vinylidene fluoride) Membranes.

    Science.gov (United States)

    Liu, Jie; Lu, Xiaolong; Wu, Chunrui

    2013-11-21

    Poly(vinylidene fluoride) (PVDF) membranes were prepared by non solvent induced phase separation (NIPS), melt spinning and the solution-cast method. The effect of preparation methods with different membrane formation mechanisms on crystallization behavior and tensile strength of PVDF membranes was investigated. Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) and X-ray diffraction (XRD) were employed to examine the crystal form of the surface layers and the overall membranes, respectively. Spherulite morphologies and thermal behavior of the membranes were studied by polarized light optical microscopy (PLO) and differential scanning calorimetry (DSC) separately. It was found that the crystallization behavior of PVDF membranes was closely related to the preparation methods. For membranes prepared by the NIPS method, the skin layers had a mixture of α and β phases, the overall membranes were predominantly α phase, and the total crystallinity was 60.0% with no spherulite. For melt spinning membranes, the surface layers also showed a mixture of α and β phases, the overall membranes were predominantly α phase. The total crystallinity was 48.7% with perfect spherulites. Whereas the crystallization behavior of solution-cast membranes was related to the evaporation temperature and the additive, when the evaporation temperature was 140 °C with a soluble additive in the dope solution, obvious spherulites appeared. The crystalline morphology of PVDF exerted a great influence on the tensile strength of the membranes, which was much higher with perfect spherulites.

  7. A study on fatigue crack growth behavior subjected to a single tensile overload

    International Nuclear Information System (INIS)

    Lee, S.Y.; Liaw, P.K.; Choo, H.; Rogge, R.B.

    2011-01-01

    Neutron diffraction and electric potential experiments were carried out to investigate the growth behavior of a fatigue crack subjected to a single tensile overload. The specific objectives were to (i) probe the crack tip deformation and fracture behaviors under applied loads; (ii) examine the overload-induced transient crack growth micromechanism; (iii) validate the effective stress intensity factor range based on the crack closure approach as the fatigue crack tip driving force; and (iv) establish a quantitative relationship between the crack tip driving force and crack growth behavior. Immediately after a single tensile overload was introduced and then unloaded, the crack tip became blunt and enlarged compressive residual stresses in both magnitude and zone size were observed around the crack tip. The results show that the combined contributions of the overload-induced enlarged compressive residual stresses and crack tip blunting with secondary cracks are responsible for the observed changes in the crack opening load and the resultant post-overload transient crack growth behavior.

  8. High strain rate tensile behavior of Al-4.8Cu-1.2Mg alloy

    International Nuclear Information System (INIS)

    Bobbili, Ravindranadh; Paman, Ashish; Madhu, V.

    2016-01-01

    The purpose of the current study is to perform quasi static and high strain rate tensile tests on Al-4.8Cu-1.2Mg alloy under different strain rates ranging from 0.01–3500/s and also at temperatures of 25,100, 200 and 300 °C. The combined effect of strain rate, temperature and stress triaxiality on the material behavior is studied by testing both smooth and notched specimens. Johnson–Cook (J–C) constitutive and fracture models are established based on high strain rate tensile data obtained from Split hopkinson tension bar (SHTB) and quasi-static tests. By modifying the strain hardening and strain rate hardening terms in the Johnson–Cook (J–C) constitutive model, a new J–C constitutive model of Al-4.8Cu-1.2Mg alloy was obtained. The improved Johnson–Cook constitutive model matched the experiment results very well. With the Johnson–Cook constitutive and fracture models, numerical simulations of tensile tests at different conditions for Al-4.8Cu-1.2Mg alloy were conducted. Numerical simulations are performed using a non-linear explicit finite element code autodyn. Good agreement is obtained between the numerical simulation results and the experiment results. The fracture surfaces of specimens tested under various strain rates and temperatures were studied under scanning electron microscopy (SEM).

  9. Characterization of the failure behavior of zinc coating on dual phase steel under tensile deformation

    International Nuclear Information System (INIS)

    Song Guiming; Sloof, Willem G.

    2011-01-01

    Highlights: → The microcracks and voids at the zinc grain boundaries are the initial sites for the coating cracking. → The crack spacing of the fragmentally fractured zinc coating is mainly determined by the zinc grain size. → Small zinc grain size and the c-axis direction of zinc grain parallel to the zinc surface are beneficial to the mitigation of the zinc coating delamination. - Abstract: The failure behavior of hot-dip galvanized zinc coatings on dual phase steels under tensile deformation is characterized with in situ scanning electron microscopy (SEM). Under tension, the pre-existed microcracks and voids at the zinc grain boundaries propagate along the zinc grain boundaries to form crack nets within the coating, leading to a segmented fracture of the zinc coating with the crack spacing approximately equal to the zinc grain size. With further loading, the coating segments partially delaminated along the interface between the top zinc layer and the inhibition layer instead of the interface between the inhibition layer and steel substrate. As the c-axis of zinc grains trends to be normal to the tensile loading direction, the twinning deformation became more noticeable, and meanwhile the coating delamination was diminished. The transverse and incline tunneling cracks occurred in the inhibition layer with tensile deformation. The existence of the brittle FeZn 13 particles on top of the inhibition layer was unfavorable to the coating adhesion.

  10. Post-irradiation diarrhea

    International Nuclear Information System (INIS)

    Meerwaldt, J.H.

    1984-01-01

    In radiotherapy of pelvic cancers, the X-ray dose to be delivered to the tumour is limited by the tolerance of healthy surrounding tissue. In recent years, a number of serious complications of irradiation of pelvic organs were encountered. Modern radiotherapy necessitates the acceptance of a calculated risk of complications in order to achieve a better cure rate. To calculate these risks, one has to know the radiation dose-effect relationship of normal tissues. Of the normal tissues most at risk when treating pelvic tumours only the bowel is studied. In the literature regarding post-irradiation bowel complications, severe and mild complications are often mixed. In the present investigation the author concentrated on the group of patients with relatively mild symptoms. He studied the incidence and course of post-irradiation diarrhea in 196 patients treated for carcinoma of the uterine cervix or endometrium. The aims of the present study were: 1) to determine the incidence, course and prognostic significance of post-irradiation diarrhea; 2) to assess the influence of radiotherapy factors; 3) to study the relation of bile acid metabolism to post-irradiation diarrhea; 4) to investigate whether local factors (reservoir function) were primarily responsible. (Auth.)

  11. Coating of carbon nanotube fibers: variation of tensile properties, failure behavior and adhesion strength

    Directory of Open Access Journals (Sweden)

    Edith eMäder

    2015-07-01

    Full Text Available An experimental study of the tensile properties of CNT fibers and their interphasial behavior in epoxy matrices is reported. One of the most promising applications of CNT fibers is their use as reinforcement in multifunctional composites. For this purpose, an increase of the tensile strength of the CNT fibers in unidirectional composites as well as strong interfacial adhesion strength is desirable. However, the mechanical performance of the CNT fiber composites manufactured so far is comparable to that of commercial fiber composites. The interfacial properties of CNT fiber/polymer composites have rarely been investigated and provided CNT fiber/epoxy interfacial shear strength of 14.4 MPa studied by the microbond test.In order to improve the mechanical performance of the CNT fibers, an epoxy compatible coating with nano-dispersed aqueous based polymeric film formers and low viscous epoxy resin, respectively, was applied. For impregnation of high homogeneity, low molecular weight epoxy film formers and polyurethane film formers were used. The aqueous based epoxy film formers were not crosslinked and able to interdiffuse with the matrix resin after impregnation. Due to good wetting of the individual CNT fibers by the film formers, the degree of activation of the fibers was improved leading to increased tensile strength and Young’s modulus. Cyclic tensile loading and simultaneous determination of electric resistance enabled to characterize the fiber’s durability in terms of elastic recovery and hysteresis.The pull-out tests and SEM study reveal different interfacial failure mechanisms in CNT fiber/epoxy systems for untreated and film former treated fibers, on the one hand, and epoxy resin treated ones, on the other hand. The epoxy resin penetrated between the CNT bundles in the reference or film former coated fiber, forming a relatively thick CNT/epoxy composite layer and thus shifting the fracture zone within the fiber. In contrast to this

  12. Strain rate dependent tensile behavior of advanced high strength steels: Experiment and constitutive modeling

    International Nuclear Information System (INIS)

    Kim, Ji-Hoon; Kim, Daeyong; Han, Heung Nam; Barlat, F.; Lee, Myoung-Gyu

    2013-01-01

    High strain rate tensile tests were conducted for three advanced high strength steels: DP780, DP980 and TRIP780. A high strain rate tensile test machine was used for applying the strain rate ranging from 0.1/s to 500/s. Details of the measured stress–strain responses were comparatively analyzed for the DP780 and TRIP780 steels which show similar microstructural feature and ultimate tensile strength, but different strengthening mechanisms. The experimental observations included: usual strain rate dependent plastic flow stress behavior in terms of the yield stress (YS), the ultimate tensile strength (UTS), the uniform elongation (UE) and the total elongation (TE) which were observed for the three materials. But, higher strain hardening rate at early plastic strain under quasi-static condition than that of some increased strain rates was featured for TRIP780 steel, which might result from more active transformation during deformation with lower velocity. The uniform elongation that explains the onset of instability and the total elongation were larger in case of TRIP steel than the DP steel for the whole strain rate range, but interestingly the fracture strain measured by the reduction of area (RA) method showed that the TRIP steel has lower values than DP steel. The fractographs using scanning electron microscopy (SEM) at the fractured surfaces were analyzed to relate measured fracture strain and the microstructural difference of the two materials during the process of fracture under various strain rates. Finally, constitutive modeling for the plastic flow stresses under various strain rates was provided in this study. The proposed constitutive law could represent both Hollomon-like and Voce-like hardening laws and the ratio between the two hardening types was efficiently controlled as a function of strain rate. The new strength model was validated successfully under various strain rates for several grades of steels such as mild steels, DP780, TRIP780, DP980 steels.

  13. The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

    International Nuclear Information System (INIS)

    Wang, Y.Q.; Zheng, Y.F.; Cai, W.; Zhao, L.C.

    1999-01-01

    Recently, ternary Ti-Ni-Hf alloys have attracted great interest in the field of high temperature shape memory materials research and development. Extensive studies have been made on its manufacture process, constitutional phases, phase transformation behavior, the structure, substructure and interface structure of martensite and the precipitation behavior during ageing. Yet up to date there is no report about the fundamental mechanical properties of Ti-Ni-Hf alloys, such as the stress-strain data, the variation laws of the yield strength and elongation with the temperature. In the present study, tensile tests at various temperatures are employed to investigate the mechanical behavior of Ti-Ni-Hf alloy with different matrix structures, from full martensite to full parent phase structure, with the corresponding deformation mechanism discussed

  14. The effect of sheet processing on the microstructure, tensile, and creep behavior of INCONEL alloy 718

    Science.gov (United States)

    Boehlert, C. J.; Dickmann, D. S.; Eisinger, Ny. N. C.

    2006-01-01

    The grain size, grain boundary character distribution (GBCD), creep, and tensile behavior of INCONEL alloy 718 (IN 718) were characterized to identify processing-microstructure-property relationships. The alloy was sequentially cold rolled (CR) to 0, 10, 20, 30, 40, 60, and 80 pct followed by annealing at temperatures between 954 °C and 1050 °C and the traditional aging schedule used for this alloy. In addition, this alloy can be superplastically formed (IN 718SPF) to a significantly finer grain size and the corresponding microstructure and mechanical behavior were evaluated. The creep behavior was evaluated in the applied stress (σ a ) range of 300 to 758 MPa and the temperature range of 638 °C to 670 °C. Constant-load tensile creep experiments were used to measure the values of the steady-state creep rate and the consecutive load reduction method was used to determine the values of backstress (σ0). The values for the effective stress exponent and activation energy suggested that the transition between the rate-controlling creep mechanisms was dependent on effective stresses (σ e =σ a σ0) and the transition occurred at σ e ≅ 135 MPa. The 10 to 40 pct CR samples exhibited the greatest 650 °C strength, while IN 718SPF exhibited the greatest room-temperature (RT) tensile strength (>1550 MPa) and ductility (ɛ f >16 pct). After the 954 °C annealing treatment, the 20 pct CR and 30 pct CR microstructures exhibited the most attractive combination of elevated-temperature tensile and creep strength, while the most severely cold-rolled materials exhibited the poorest elevated-temperature properties. After the 1050 °C annealing treatment, the IN 718SPF material exhibited the greatest backstress and best creep resistance. Electron backscattered diffraction was performed to identify the GBCD as a function of CR and annealing. The data indicated that annealing above 1010 °C increased the grain size and resulted in a greater fraction of twin boundaries, which in

  15. Microstructure and dynamic tensile behavior of DP600 dual phase steel joint by laser welding

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Danyang, E-mail: dongdanyang@mail.neu.edu.cn [College of Science, Northeastern University, No. 11, Lane 3, WenHua Road, HePing District, Shenyang 110819 (China); Liu, Yang, E-mail: liuyang@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Yang, Yuling, E-mail: yulingyang@mail.neu.edu.cn [College of Science, Northeastern University, No. 11, Lane 3, WenHua Road, HePing District, Shenyang 110819 (China); Li, Jinfeng, E-mail: lijinfengboda@163.com [College of Science, Northeastern University, No. 11, Lane 3, WenHua Road, HePing District, Shenyang 110819 (China); Ma, Min, E-mail: sharon6789@163.com [College of Science, Northeastern University, No. 11, Lane 3, WenHua Road, HePing District, Shenyang 110819 (China); Jiang, Tao, E-mail: tao.jiang906@yahoo.com [College of Science, Northeastern University, No. 11, Lane 3, WenHua Road, HePing District, Shenyang 110819 (China)

    2014-01-31

    Dual phase (DP) steels have been widely used in the automotive industry to reduce vehicle weight and improve car safety. In such applications welding and joining have to be involved, which would lead to a localized change of the microstructure and property, and create potential safety and reliable issues under dynamic loading. The aim of the present study is to examine the rate-dependent mechanical properties, deformation and fracture behavior of DP600 steel and its welded joint (WJ) produced by Nd:YAG laser welding over a wide range of strain rates (0.001–1133 s{sup −1}). Laser welding results in not only significant microhardness increase in the fusion zone (FZ) and inner heat-affected zone (HAZ), but also the formation of a softened zone in the outer HAZ. The yield strength (YS) of the DP600 steel increases and the ultimate tensile strength (UTS) remains almost unchanged, but the ductility decreases after welding. The DP600 base metal (BM) and WJ are of positive strain rate sensitivity and show similar stress–strain response at all studied strain rates. The enhanced ductility at strain rates ranging from 1 to 100 s{sup −1} is attributed to the retardation of the propagation of plastic strain localization due to the positive strain rate sensitivity and the thermal softening caused by deformation induced adiabatic temperature rise during dynamic tensile deformation. The tensile failure occurs in the inner HAZ of the joint and the distance of failure location from the weld centerline decreases with increasing strain rate. The mechanism for the changing failure location can be related to the different strain rate dependence of the plastic deformation behavior of the microstructures in various regions across the joint. The DP600 WJ absorbs more energy over the whole measured strain rates than that of the BM due to the higher strength at the same strain when the deformation only up to 10% is considered.

  16. Effect of High Temperature on the Tensile Behavior of CFRP and Cementitious Composites

    Science.gov (United States)

    Toutanji, Houssam A.

    1999-01-01

    Concrete and other composite manufacturing processes are continuing to evolve and become more and more suited for use in non-Earth settings such as the Moon and Mars. The fact that structures built in lunar environments would experience a range of effects from temperature extremes to bombardment by micrometeorites and that all the materials for concrete production exist on the Moon means that concrete appears to be the most feasible building material. it can provide adequate shelter from the harshness of the lunar environment and at the same time be a cost effective building material. With a return to the Moon planned by NASA to occur after the turn of the century, it will be necessary to include concrete manufacturing as one of the experiments to be conducted in one of the coming missions. Concrete's many possible uses and possibilities for manufacturing make it ideal for lunar construction. The objectives of this research are summarized as follows: i) study the possibility of concrete production on the Moon or other planets, ii) study the effect of high temperature on the tensile behavior of concrete, and iii) study the effect of high temperature on the tensile behavior of carbon fiber reinforced with inorganic polymer composites. Literature review indicates that production of concrete on the Moon or other planets is feasible using the indigenous materials. Results of this study has shown that both the tensile strength and static elastic modulus of concrete decreased with a rise in temperature from 200 to 500 C. The addition of silica fume to concrete showed higher resistance to high temperatures. Carbon fiber reinforced inorganic polymer (CFRIP) composites seemed to perform well up to 300 C. However, a significant reduction in strength was observed of about 40% at 400 C and up to 80% when the specimens were exposed to 700 C.

  17. Experimental and numerical modeling of basalt textile reinforced mortar behavior under uniaxial tensile stress

    International Nuclear Information System (INIS)

    Larrinaga, Pello; Chastre, Carlos; Biscaia, Hugo C.; San-José, José T.

    2014-01-01

    Highlights: • Making more deepen the knowledge of textile reinforced mortar in tensile stress. • Analyzing the effect of the reinforcing ratio of the composite. • To compare results with Aveston–Cooper–Kelly theory. • To develop a numerical model based on a finite element code. • Considering the importance of the bond-slip law of the mortar-to-textile-interface. - Abstract: During the last years several projects and studies have improved the knowledge about textile reinforced mortar (TRM) technology. TRM has already been used in strengthening masonry and reinforced concrete structural elements such as walls, arches, columns and beams. This material is presented as a real alternative to the use of fiber-reinforced polymers (FRP) in situations where these composites have presented some drawbacks or their use is banned. Textile reinforced mortar show a complex mechanical behavior derived from the heterogeneity of the constituent materials. This paper aims to deepen the knowledge of this composite material in terms of tensile behavior. Following this scope, this paper presents an experimental campaign focused on thirty-one TRM specimens reinforced with four different reinforcing ratios. The results are analyzed and contrasted with two distinct models. (i) The Aveston–Cooper–Kelly theory (ACK) which is based on a tri-linear analytical approach; and (ii) a non-linear numerical simulation with a 3D finite element code. The finite element analysis (FEA) of the TRM tensile tests also showed no significant dependence on the basalt-to-mortar interface, i.e., the choice of a bond-slip curve in order to reproduce the bond stresses and slippages along the interface is irrelevant and it can be simply considered as rigid interface

  18. Tensile and fracture behavior of AA6061-T6 aluminum alloys: micro-mechanical approach

    International Nuclear Information System (INIS)

    Shen, Y.

    2012-01-01

    The AA6061-T6 aluminum alloy was chosen as the material for the core vessel of the future Jules Horowitz testing reactor (JHR). The objective of this thesis is to understand and model the tensile and fracture behavior of the material, as well as the origin of damage anisotropy. A micro-mechanical approach was used to link the microstructure and mechanical behavior. The microstructure of the alloy was characterized on the surface via Scanning Electron Microscopy and in the 3D volume via synchrotron X-ray tomography and laminography. The damage mechanism was identified by in-situ SEM tensile testing, ex-situ X-ray tomography and in-situ laminography on different levels of triaxiality. The observations have shown that damage nucleated at lower strains on Mg 2 Si coarse precipitates than on iron rich intermetallics. The identified scenario and the in-situ measurements were then used to develop a coupled GTN damage model incorporating nucleation, growth and coalescence of cavities formed by coarse precipitates. The relationship between the damage and the microstructure anisotropies was explained and simulated. (author)

  19. Effect of tensile mean stress on fatigue behavior of single-crystal and directionally solidified superalloys

    Science.gov (United States)

    Kalluri, Sreeramesh; Mcgaw, Michael A.

    1990-01-01

    Two nickel base superalloys, single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf, were studied in view of the potential usage of the former and usage of the latter as blade materials for the turbomachinery of the space shuttle main engine. The baseline zero mean stress (ZMS) fatigue life (FL) behavior of these superalloys was established, and then the effect of tensile mean stress (TMS) on their FL behavior was characterized. At room temperature these superalloys have lower ductilities and higher strengths than most polycrystalline engineering alloys. The cycle stress-strain response was thus nominally elastic in most of the fatigue tests. Therefore, a stress range based FL prediction approach was used to characterize both the ZMS and TMS fatigue data. In the past, several researchers have developed methods to account for the detrimental effect of tensile mean stress on the FL for polycrystalline engineering alloys. However, the applicability of these methods to single crystal and directionally solidified superalloys has not been established. In this study, these methods were applied to characterize the TMS fatigue data of single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf and were found to be unsatisfactory. Therefore, a method of accounting for the TMS effect on FL, that is based on a technique proposed by Heidmann and Manson was developed to characterize the TMS fatigue data of these superalloys. Details of this method and its relationship to the conventionally used mean stress methods in FL prediction are discussed.

  20. Tensile Fracture Behavior of 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

    Science.gov (United States)

    Cooper, A. J.; Brayshaw, W. J.; Sherry, A. H.

    2018-02-01

    Herein we investigate how the oxygen content in hot isostatically pressed (HIP'd) 316L stainless steel affects the mechanical properties and tensile fracture behavior. This work follows on from previous studies, which aimed to understand the effect of oxygen content on the Charpy impact toughness of HIP'd steel. We expand on the work by performing room-temperature tensile testing on different heats of 316L stainless steel, which contain different levels of interstitial elements (carbon and nitrogen) as well as oxygen in the bulk material. Throughout the work we repeat the experiments on conventionally forged 316L steel as a reference material. The analysis of the work indicates that oxygen does not contribute to a measureable solution strengthening mechanism, as is the case with carbon and nitrogen in austenitic stainless steels (Werner in Mater Sci Eng A 101:93-98, 1988). Neither does oxygen, in the form of oxide inclusions, contribute to precipitation hardening due to the size and spacing of particles. However, the oxide particles do influence fracture behavior; fractography of the failed tension test specimens indicates that the average ductile dimple size is related to the oxygen content in the bulk material, the results of which support an on-going hypothesis relating oxygen content in HIP'd steels to their fracture mechanisms by providing additional sites for the initiation of ductile damage in the form of voids.

  1. Effect of Thermal Cycling on the Tensile Behavior of Polymer Composites Reinforced by Basalt and Carbon Fibers

    Science.gov (United States)

    Khalili, S. Mohammad Reza; Najafi, Moslem; Eslami-Farsani, Reza

    2017-01-01

    The aim of the present work was to investigate the effect of thermal cycling on the tensile behavior of three types of polymer-matrix composites — a phenolic resin reinforced with woven basalt fibers, woven carbon fibers, and hybrid basalt and carbon fibers — in an ambient environment. For this purpose, tensile tests were performed on specimens previously subjected to a certain number of thermal cycles. The ultimate tensile strength of the specimen reinforced with woven basalt fibers had by 5% after thermal cycling, but the strength of the specimen with woven carbon fibers had reduced to a value by 11% higher than that before thermal cycling.

  2. Application of Gurson–Tvergaard–Needleman Constitutive Model to the Tensile Behavior of Reinforcing Bars with Corrosion Pits

    Science.gov (United States)

    Xu, Yidong; Qian, Chunxiang

    2013-01-01

    Based on meso-damage mechanics and finite element analysis, the aim of this paper is to describe the feasibility of the Gurson–Tvergaard–Needleman (GTN) constitutive model in describing the tensile behavior of corroded reinforcing bars. The orthogonal test results showed that different fracture pattern and the related damage evolution process can be simulated by choosing different material parameters of GTN constitutive model. Compared with failure parameters, the two constitutive parameters are significant factors affecting the tensile strength. Both the nominal yield and ultimate tensile strength decrease markedly with the increase of constitutive parameters. Combining with the latest data and trial-and-error method, the suitable material parameters of GTN constitutive model were adopted to simulate the tensile behavior of corroded reinforcing bars in concrete under carbonation environment attack. The numerical predictions can not only agree very well with experimental measurements, but also simplify the finite element modeling process. PMID:23342140

  3. Postirradiation examination of HTR fuel

    International Nuclear Information System (INIS)

    Nabielek, H.; Reitsamer, G.; Kania, M.J.

    1986-01-01

    Fuel for the High Temperature Reactor (HTR) consists of 1 mm diameter coated particles uniformly distributed in a graphite matrix within a cold-molded 60 mm diameter spherical fuel element. Fuel performance demonstrations under simulated normal operation conditions are conducted in accelerated neutron environments available in Material Test Reactors and in real-time environments such as the Arbeitsgemeinschaft Versuchsreaktor (AVR) Juelich. Postirradiation examinations are then used to assess fuel element behavior and the detailed performance of the coated particles. The emphasis in postirradiation examination and accident testing is on assessment of the capability for fuel elements and individual coated particles to retain fission products and actinide fuel materials. To accomplish this task, techniques have been developed which measures fission product and fuel material distributions within or exterior to the particle: Hot Gas Chlorination - provides an accurate method to measure total fuel material concentration outside intact particles; Profile Electrolytic Deconsolidation - permits determination of fission product distribution along fuel element diameter and retrieval of fuel particles from positions within element; Gamma Spectrometry - provides nondestructive method to measure defect particle fractions based on retention of volatile metallic fission products; Particle Cracking - permits a measure of the partitioning of fission products between fuel kernel and particle coatings, and the derivation of diffusion parameters in fuel materials; Micro Gas Analysis - provides gaseous fission product and reactive gas inventory within free volume of single particles; and Mass-spectrometric Burnup Determination - utilizes isotope dilution for the measurement of heavy metal isotope abundances

  4. A Simplified Micromechanical Modeling Approach to Predict the Tensile Flow Curve Behavior of Dual-Phase Steels

    Science.gov (United States)

    Nanda, Tarun; Kumar, B. Ravi; Singh, Vishal

    2017-11-01

    Micromechanical modeling is used to predict material's tensile flow curve behavior based on microstructural characteristics. This research develops a simplified micromechanical modeling approach for predicting flow curve behavior of dual-phase steels. The existing literature reports on two broad approaches for determining tensile flow curve of these steels. The modeling approach developed in this work attempts to overcome specific limitations of the existing two approaches. This approach combines dislocation-based strain-hardening method with rule of mixtures. In the first step of modeling, `dislocation-based strain-hardening method' was employed to predict tensile behavior of individual phases of ferrite and martensite. In the second step, the individual flow curves were combined using `rule of mixtures,' to obtain the composite dual-phase flow behavior. To check accuracy of proposed model, four distinct dual-phase microstructures comprising of different ferrite grain size, martensite fraction, and carbon content in martensite were processed by annealing experiments. The true stress-strain curves for various microstructures were predicted with the newly developed micromechanical model. The results of micromechanical model matched closely with those of actual tensile tests. Thus, this micromechanical modeling approach can be used to predict and optimize the tensile flow behavior of dual-phase steels.

  5. Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

    Science.gov (United States)

    Alturk, Rakan; Hector, Louis G.; Matthew Enloe, C.; Abu-Farha, Fadi; Brown, Tyson W.

    2018-06-01

    The dependence of the plastic anisotropy on the nominal strain rate for a medium-manganese (10 wt.% Mn) transformation-induced plasticity (TRIP) steel with initial austenite volume fraction of 66% (balance ferrite) has been investigated. The material exhibited yield point elongation, propagative instabilities during hardening, and austenite transformation to α'-martensite either directly or through ɛ-martensite. Uniaxial strain rates within the range of 0.005-500 s-1 along the 0°, 45°, and 90° orientations were selected based upon their relevance to automotive applications. The plastic anisotropy ( r) and normal anisotropy ( r n) indices corresponding to each direction and strain rate were determined using strain fields obtained from stereo digital image correlation systems that enabled both quasistatic and dynamic measurements. The results provide evidence of significant, orientation-dependent strain rate effects on both the flow stress and the evolution of r and r n with strain. This has implications not only for material performance during forming but also for the development of future strain-rate-dependent anisotropic yield criteria. Since tensile data alone for the subject medium-manganese TRIP steel do not satisfactorily determine the microstructural mechanisms responsible for the macroscopic-scale behavior observed on tensile testing, additional tests that must supplement the mechanical test results presented herein are discussed.

  6. Tensile and fatigue behavior of polymer composites reinforced with superelastic SMA strands

    Science.gov (United States)

    Daghash, Sherif M.; Ozbulut, Osman E.

    2018-06-01

    This study explores the use of superelastic shape memory alloy (SMA) strands, which consist of seven individual small-diameter wires, in an epoxy matrix and characterizes the tensile and fatigue responses of the developed SMA/epoxy composites. Using a vacuum assisted hand lay-up technique, twelve SMA fiber reinforced polymer (FRP) specimens were fabricated. The developed SMA-FRP composites had a fiber volume ratio of 50%. Tensile response of SMA-FRP specimens were characterized under both monotonic loading and increasing amplitude loading and unloading cycles. The degradation in superelastic properties of the developed SMA-FRP composites during fatigue loading at different strain amplitudes was investigated. The effect of loading rate on the fatigue response of SMA-FRP composites was also explored. In addition, fractured specimens were examined using the scanning electron microscopy (SEM) technique to study the failure mechanisms of the tested specimens. A good interfacial bonding between the SMA strands and epoxy matrix was observed. The developed SMA-FRP composites exhibited good superelastic behavior at different strain amplitudes up to at least 800 cycle after which significant degradation occurred.

  7. Tensile and Creep Behavior of Extruded AA6063/SiCp Al MMCs

    International Nuclear Information System (INIS)

    Khalifa, Tarek A.; Mahmoud, Tamer S.

    2010-01-01

    Composites of AA6063 Al alloy reinforced with SiC particles (SiC p ) were prepared by the vortex method. Hot extrusion was carried out for the as cast composites with a reduction in area of 25%. Tensile and creep behavior of as-cast and extruded composites were studied at elevated temperatures. Tensile tests carried out at room temperature showed that for the as-cast composites, the addition of SiC p up to 10% by weight improves the strength but reduces ductility. Further addition of SiC p reduces the strength and ductility of the composites. At 150 and 300 deg. C the matrix alloy exhibits higher strength than the composites. Extrusion generally raised the strength of the composites at both room and elevated temperatures. Time rupture creep tests carried out at 300 deg. C showed that the composites exhibit higher creep resistance as compared to the matrix alloy except at relatively low stresses where the matrix has a better creep resistance. Extrusion improved the resistance of composites to creep rupture.

  8. Effect of laser shock on tensile deformation behavior of a single crystal nickel-base superalloy

    International Nuclear Information System (INIS)

    Lu, G.X.; Liu, J.D.; Qiao, H.C.; Zhou, Y.Z.; Jin, T.; Zhao, J.B.; Sun, X.F.; Hu, Z.Q.

    2017-01-01

    This investigation focused on the tensile deformation behavior of a single crystal nickel-base superalloy, both in virgin condition and after laser shock processing (LSP) with varied technology parameters. Nanoindention tests were carried out on the sectioned specimens after LSP treatment to characterize the surface strengthening effect. Stress strain curves of tensile specimens were analyzed, and microstructural observations of the fracture surface and the longitudinal cross-sections of ruptured specimens were performed via scanning electron microscope (SEM), in an effort to clarify the fracture mechanisms. The results show that a surface hardening layer with the thickness of about 0.3–0.6 mm was gained by the experimental alloys after LSP treatment, but the formation of surface hardening layer had not affected the yield strength. Furthermore, fundamental differences in the plastic responses at different temperatures due to LSP treatment had been discovered. At 700 °C, the slip deformation was held back when it extended to the surface hardening layer and the ensuing slip steps improved the plasticity; however, at 1000 °C, surface hardening layer hindered the macro necking, which resulted in the relatively lower plasticity.

  9. Effect of laser shock on tensile deformation behavior of a single crystal nickel-base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, G.X. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Liu, J.D., E-mail: jdliu@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Qiao, H.C. [Shenyang Institute of Automation, Chinese Academy of Sciences, 114 Nanta Road, Shenyang 110016 (China); Zhou, Y.Z. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Jin, T., E-mail: tjin@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Zhao, J.B. [Shenyang Institute of Automation, Chinese Academy of Sciences, 114 Nanta Road, Shenyang 110016 (China); Sun, X.F.; Hu, Z.Q. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2017-02-16

    This investigation focused on the tensile deformation behavior of a single crystal nickel-base superalloy, both in virgin condition and after laser shock processing (LSP) with varied technology parameters. Nanoindention tests were carried out on the sectioned specimens after LSP treatment to characterize the surface strengthening effect. Stress strain curves of tensile specimens were analyzed, and microstructural observations of the fracture surface and the longitudinal cross-sections of ruptured specimens were performed via scanning electron microscope (SEM), in an effort to clarify the fracture mechanisms. The results show that a surface hardening layer with the thickness of about 0.3–0.6 mm was gained by the experimental alloys after LSP treatment, but the formation of surface hardening layer had not affected the yield strength. Furthermore, fundamental differences in the plastic responses at different temperatures due to LSP treatment had been discovered. At 700 °C, the slip deformation was held back when it extended to the surface hardening layer and the ensuing slip steps improved the plasticity; however, at 1000 °C, surface hardening layer hindered the macro necking, which resulted in the relatively lower plasticity.

  10. Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

    Science.gov (United States)

    Alturk, Rakan; Hector, Louis G.; Matthew Enloe, C.; Abu-Farha, Fadi; Brown, Tyson W.

    2018-04-01

    The dependence of the plastic anisotropy on the nominal strain rate for a medium-manganese (10 wt.% Mn) transformation-induced plasticity (TRIP) steel with initial austenite volume fraction of 66% (balance ferrite) has been investigated. The material exhibited yield point elongation, propagative instabilities during hardening, and austenite transformation to α'-martensite either directly or through ɛ-martensite. Uniaxial strain rates within the range of 0.005-500 s-1 along the 0°, 45°, and 90° orientations were selected based upon their relevance to automotive applications. The plastic anisotropy (r) and normal anisotropy (r n) indices corresponding to each direction and strain rate were determined using strain fields obtained from stereo digital image correlation systems that enabled both quasistatic and dynamic measurements. The results provide evidence of significant, orientation-dependent strain rate effects on both the flow stress and the evolution of r and r n with strain. This has implications not only for material performance during forming but also for the development of future strain-rate-dependent anisotropic yield criteria. Since tensile data alone for the subject medium-manganese TRIP steel do not satisfactorily determine the microstructural mechanisms responsible for the macroscopic-scale behavior observed on tensile testing, additional tests that must supplement the mechanical test results presented herein are discussed.

  11. Post-irradiation examinations and theoretical analyses of the fuel and fuel pin behavior of innovative systems

    International Nuclear Information System (INIS)

    Ernst, W.; Freund, D.; Geithoff, D.; Heck, M.; Jacobi, O.; Steiner, H.; Weimar, P.

    1995-01-01

    For the development of LMR cladding materials an irradiation test was performed in the KNK II reactor between 1986 and 1991. It demonstrated that a temperature gradient in the cladding has no observable effect on swelling behavior. PIEs of transient experiments in the Petten HFR have shown no significant cladding deformations. (orig.)

  12. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  13. Tensile deformation behavior of AA5083-H111 at cold and warm temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Fahrettin; Toros, Serkan; Kilic, Suleyman [Nidge Univ. (Turkey). Dept. of Mechanical Engineering

    2010-09-15

    The effects of strain rate and temperature on the deformation behavior of hardened 5083-H111 aluminum magnesium alloy sheet were investigated by performing uniaxial tensile tests at various strain rates from 0.0083 to 0.16 s{sup -1} and temperatures from -100 to 300 C. Results from the prescribed test ranges indicate that the formability of this material at cold and warm temperatures is better than at room temperature. The improvement in formability at cold temperatures is principally due to the strain hardening of the material. However, the improvement at warm temperature and low strain rate is specifically due to the high strain rate sensitivity characteristic of the material. Results indicate that this alloy should be formed at temperatures higher than 200 C and at low strain rates. (orig.)

  14. Postirradiation examination of Kori-1 nuclear power plant fuels

    International Nuclear Information System (INIS)

    Ro, S.G.; Kim, E.K.; Lee, K.S.; Min, D.K.

    1994-01-01

    Full size fuels discharged from Kori-1 PWR nuclear power plant have been subjected to postirradiation examination. The fuels under investigation were irradiated for one- to four-reactor cycles. Nondestructive examination and dismantling of the fuel assemblies have been conducted in the pool of the postirradiation examination facility (PIEF) of Korea Atomic Energy Research Institue. Subsequently nondestructive and destructive examinations of fuel rods have been performed in the hot cells of the PIEF. An evaluation of fuel burnup behaviors was based on the postirradiation examination data and the nominal design values. The results did not show any evidence of abnormalities in the fuel integrity. (orig.)

  15. Postirradiation examination of Kori-1 nuclear power plant fuels

    Science.gov (United States)

    Seung-Gy, Ro; Eun-Ka, Kim; Key-Soon, Lee; Duck-Kee, Min

    1994-05-01

    Full size fuels discharged from Kori-1 PWR nuclear power plant have been subjected to postirradiation examination. The fuels under investigation were irradiated for one- to four-reactor cycles. Nondestructive examination and dismantling of the fuel assemblies have been conducted in the pool of the postirradiation examination facility (PIEF) of Korea Atomic Energy Research Institute. Subsequently nondestructive and destructive examinations of fuel rods have been performed in the hot cells of the PIEF. An evaluation of fuel burnup behaviors was based on the postirradiation examination data and the nominal design values. The results did not show any evidence of abnormalities in the fuel integrity.

  16. Meso-Scale Progressive Damage Behavior Characterization of Triaxial Braided Composites under Quasi-Static Tensile Load

    Science.gov (United States)

    Ren, Yiru; Zhang, Songjun; Jiang, Hongyong; Xiang, Jinwu

    2018-04-01

    Based on continuum damage mechanics (CDM), a sophisticated 3D meso-scale finite element (FE) model is proposed to characterize the progressive damage behavior of 2D Triaxial Braided Composites (2DTBC) with 60° braiding angle under quasi-static tensile load. The modified Von Mises strength criterion and 3D Hashin failure criterion are used to predict the damage initiation of the pure matrix and fiber tows. A combining interface damage and friction constitutive model is applied to predict the interface damage behavior. Murakami-Ohno stiffness degradation scheme is employed to predict the damage evolution process of each constituent. Coupling with the ordinary and translational symmetry boundary conditions, the tensile elastic response including tensile strength and failure strain of 2DTBC are in good agreement with the available experiment data. The numerical results show that the main failure modes of the composites under axial tensile load are pure matrix cracking, fiber and matrix tension failure in bias fiber tows, matrix tension failure in axial fiber tows and interface debonding; the main failure modes of the composites subjected to transverse tensile load are free-edge effect, matrix tension failure in bias fiber tows and interface debonding.

  17. Anisotropy in tensile and ductile-brittle transition behavior of ODS ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Kasada, R., E-mail: r-kasada@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University, Uji, Kyoto (Japan); Lee, S.G.; Isselin, J.; Lee, J.H.; Omura, T.; Kimura, A. [Institute of Advanced Energy, Kyoto University, Uji, Kyoto (Japan); Okuda, T. [KOBELCO Research Institute, 1-5-5, Takatsukadai, Nishi-ku, Kobe 651-2271 (Japan); Inoue, M. [Japan Atomic Energy Agency, 4002 Narita, Oarai, Ibaraki 311-1393 (Japan); Ukai, S.; Ohnuki, S. [Materials Science and Engineering, Hokkaido University, N14 W8, Kita ku, Sapporo 060-8626 (Japan); Fujisawa, T. [Nagoya University, Furocho, Chikusa, Nagoya 464-8603 (Japan); Abe, F. [National Institute of Materials Science, Tsukuba, (NIMS), 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2011-10-01

    Anisotropic fracture behavior of SOC-1 oxide dispersion strengthened (ODS) ferritic steel has been investigated for a hot-extruded bar by tensile tests and Charpy impact tests. These mechanical properties are better in the longitudinal direction than in the transverse directions against extrusion direction (ED). Fracture surface observations by scanning electron microscopy and auger electron spectroscopy indicated bundle-like morphology with existence of segregation/precipitation/inclusions along ED. Pole figures of the hot-extruded bar characterized using electron back scattering diffraction (EBSD) technique and X-ray diffraction exhibited <1 1 0> fiber texture formation along ED. The EBSD orientation map showed a complex bundle-like grain morphology which consists of elongated grains having a specific orientation <1 1 0>// ED and relatively isotropic and small grains having other orientation. The results conclude that the combined effects of observed elongated grain morphology and these small grains with segregation/precipitation/inclusions along ED can explain the anisotropic fracture behavior of the hot-extruded ODS ferritic steel.

  18. Tensile behavior of humid aged advanced composites for helicopter external fuel tank development

    Directory of Open Access Journals (Sweden)

    Condruz Mihaela

    2018-01-01

    Full Text Available Influence of humid aging on tensile properties of two polymeric composites was studied. The purpose of the study was to evaluate the suitability of the materials for a naval helicopter external fuel tank. Due to the application, the humid environment was kerosene and saline solution to evaluate the sea water effect on the composite tensile strength. The composite samples were immersed in kerosene for 168 hours, respective 1752 hours and in saline solution for 168 hours. Tensile tests were performed after the immersion. The composite sample tensile tests showed that kerosene and saline solution had no influence on the elastic modulus of the materials, but it was observed a slight improvement of the tensile strength of the two polymeric composites.

  19. A combined experimental and FE analysis procedure to evaluate tensile behavior of zircaloy pressure tubes

    International Nuclear Information System (INIS)

    Samal, M.K.; Vaze, K.K.; Balakrishnan, K.S.; Anantharaman, S.

    2012-01-01

    Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward because of the presence of combined membrane as well as bending stresses arising in the loaded condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A 3-D finite element (FE) analysis was performed in order to determine the material true stress-strain curve by comparing experimental load-displacement data with those predicted by FE analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress-strain data as obtained from ring tensile specimen could describe the load displacement curve of the miniaturized flat tensile specimen very well. (author)

  20. Coarse-grained molecular dynamics simulations of the tensile behavior of a thermosetting polymer

    Science.gov (United States)

    Yang, Shaorui; Qu, Jianmin

    2014-07-01

    Using a previously developed coarse-grained model, we conducted large-scale (˜85×85×85nm3) molecular dynamics simulations of uniaxial-strain deformation to study the tensile behavior of an epoxy molding compound, epoxy phenol novolacs (EPN) bisphenol A (BPA). Under the uniaxial-strain deformation, the material is found to exhibit cavity nucleation and growth, followed by stretching of the ligaments separated by the cavities, until the ultimate failure through ligament scissions. The nucleation sites of cavities are rather random and the subsequent cavity growth accounts for much (87%) of the volumetric change during the uniaxial-strain deformation. Ultimate failure of the materials occurs when the cavity volume fraction reaches ˜60%. During the entire deformation process, polymer strands in the network are continuously extended to their linear states and broken in the postyielding strain hardening stage. When most of the strands are stretched to their taut configurations, rapid scission of a large number of strands occurs within a small strain increment, which eventually leads to fracture. Finally, through extensive numerical simulations of various loading conditions in addition to uniaxial strain, we find that yielding of the EPN-BPA can be described by the pressure-modified von Mises yield criterion.

  1. Coarse-grained molecular dynamics simulations of the tensile behavior of a thermosetting polymer.

    Science.gov (United States)

    Yang, Shaorui; Qu, Jianmin

    2014-07-01

    Using a previously developed coarse-grained model, we conducted large-scale (∼ 85 × 85 × 85 nm(3)) molecular dynamics simulations of uniaxial-strain deformation to study the tensile behavior of an epoxy molding compound, epoxy phenol novolacs (EPN) bisphenol A (BPA). Under the uniaxial-strain deformation, the material is found to exhibit cavity nucleation and growth, followed by stretching of the ligaments separated by the cavities, until the ultimate failure through ligament scissions. The nucleation sites of cavities are rather random and the subsequent cavity growth accounts for much (87%) of the volumetric change during the uniaxial-strain deformation. Ultimate failure of the materials occurs when the cavity volume fraction reaches ∼ 60%. During the entire deformation process, polymer strands in the network are continuously extended to their linear states and broken in the postyielding strain hardening stage. When most of the strands are stretched to their taut configurations, rapid scission of a large number of strands occurs within a small strain increment, which eventually leads to fracture. Finally, through extensive numerical simulations of various loading conditions in addition to uniaxial strain, we find that yielding of the EPN-BPA can be described by the pressure-modified von Mises yield criterion.

  2. Effects of surface cracks and strain rate on the tensile behavior of Balmoral Red granite

    Directory of Open Access Journals (Sweden)

    Mardoukhi Ahmad

    2015-01-01

    Full Text Available This paper presents an experimental procedure for studying the effects of surface cracks on the mechanical behavior of Balmoral Red granite under dynamic and quasi-static loading. Three different thermal shocks were applied on the surface of the Brazilian Disc test samples by keeping a flame torch at a fixed distance from the sample surface for 10, 30, and 60 seconds. Microscopy clearly shows that the number of the surface cracks increases with the duration of the thermal shock. After the thermal shock, the Brazilian Disc tests were performed using a servohydraulic materials testing machine and a compression Split Hopkinson Pressure Bar (SHPB device. The results show that the tensile strength of the rock decreases and the rate sensitivity of the rock increases as more cracks are introduced to the structure. The DIC analysis of the Brazilian disc tests shows that the fracture of the sample initiates at the center of the samples or slightly closer to the incident bar contact point. This is followed by crushing of the samples at both contact points with the stress bars.

  3. Tensile behavior of dissimilar friction stir welded joints of aluminium alloys

    International Nuclear Information System (INIS)

    Shanmuga Sundaram, N.; Murugan, N.

    2010-01-01

    The heat treatable aluminium alloy AA2024 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. The non-heat treatable aluminium alloy AA5083 possesses medium strength and high ductility and used typically in structural applications, marine, and automotive industries. When compared to fusion welding processes, friction stir welding (FSW) process is an emerging solid state joining process which is best suitable for joining these alloys. The friction stir welding parameters such as tool pin profile, tool rotational speed, welding speed, and tool axial force influence the mechanical properties of the FS welded joints significantly. Dissimilar FS welded joints are fabricated using five different tool pin profiles. Central composite design with four parameters, five levels, and 31 runs is used to conduct the experiments and response surface method (RSM) is employed to develop the model. Mathematical regression models are developed to predict the ultimate tensile strength (UTS) and tensile elongation (TE) of the dissimilar friction stir welded joints of aluminium alloys 2024-T6 and 5083-H321, and they are validated. The effects of the above process parameters and tool pin profile on tensile strength and tensile elongation of dissimilar friction stir welded joints are analysed in detail. Joints fabricated using Tapered Hexagon tool pin profile have the highest tensile strength and tensile elongation, whereas the Straight Cylinder tool pin profile have the lowest tensile strength and tensile elongation. The results are useful to have a better understanding of the effects of process parameters, to fabricate the joints with desired tensile properties, and to automate the FS welding process.

  4. Fused deposition modeling (FDM) fabricated part behavior under tensile stress, thermal cycling, and fluid pressure

    Science.gov (United States)

    Hossain, Mohammad Shojib

    Material extrusion based additive manufacturing (AM) technology, such as fused deposition modeling (FDM), is gaining popularity with the numerous 3D printers available worldwide. FDM technology is advancing from exclusively prototype construction to achieving production-grade quality. Today, FDM-fabricated parts are widely used in the aerospace industries, biomedical applications, and other industries that may require custom fabricated, low volume parts. These applications are and were possible because of the different production grade material options (e.g., acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyphenylsulfone (PPSF), etc.) available to use in FDM systems. Recent researchers are exploring other material options including polycaprolactone (PCL), polymethylmethacrylate (PMMA), composites containing ceramic, glass and metal fillers, and even metals which depict the diversified materials and possibility of new material options using FDM technology. The understanding of the behavior and mechanical properties of the finished FDM-fabricated parts is of utmost importance in the advancement of this technology. The processing parameters, e.g., build orientation, raster width (RW), contour width (CW), raster angle (RA), and raster to raster air gap (RRAG) are important factors in determining the mechanical properties of FDM fabricated parts. The work presented here focused on the mechanical properties improvement by modifying those build parameters. The main concentration is on how modifying those parameters can improve ultimate tensile stress (UTS), Young's modulus, and tensile strain of the final product. In this research, PC parts were fabricated using three build methods: 1) default method, 2) Insight revision method, and 3) visual feedback method. By modifying build parameters, the highest average UTS obtained for PC was 63.96 MPa which was 7% higher than that of 59.73 MPa obtained using the default build parameters. The parameter modification

  5. Vacancy clustering behavior in hydrogen-charged martensitic steel AISI 410 under tensile deformation

    International Nuclear Information System (INIS)

    Sugita, K; Mutou, Y; Shirai, Y

    2016-01-01

    The formation and accumulation of defects under tensile deformation of hydrogen- charged AISI 410 martensitic steels were investigated by using positron lifetime spectroscopy. During the deformation process, dislocations and vacancy-clusters were introduced and increased with increasing strains. Between hydrogen-charged and uncharged samples with the same tensile strains there was no significant difference in the dislocation density and monovacancy equivalent vacancy density. (paper)

  6. The crack propagating behavior of composite coatings prepared by PEO on aluminized steel during in situ tensile processing

    International Nuclear Information System (INIS)

    Chen Zhitong; Li Guang; Wu Zhenqiang; Xia Yuan

    2011-01-01

    Research highlights: → Composite coatings on the aluminized steel were prepared by the plasma electrolytic oxidation (PEO) technique, which comprised of Fe-Al layer, Al layer and Al 2 O 3 layer. → The evaluation method of the crack critical opening displacement δ c was introduced to describe quantitatively the resistance of Al layer to the propagation behavior of cracks and evaluate the fracture behavior of composite coatings. → The crack propagating model was established. - Abstract: This paper investigates the in situ tensile cracks propagating behavior of composite coatings on the aluminized steel generated using the plasma electrolytic oxidation (PEO) technique. Cross-sectional micrographs and elemental compositions were investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The composite coatings were shown to consist of Fe-Al, Al and Al 2 O 3 layers. The cracks propagating behavior was observed in real-time in situ SEM tensile test. In tensile process, the cracks were temporarily stopped when cracks propagated from Fe-Al layer to Al layer. The critical crack opening displacement δ c was introduced to quantitatively describe the resistance of the Al layer. There was a functional relation among the thickness ratio t Al /t Al 2 O 3 , the δ c of composite coatings and tensile cracks' spacing. The δ c increased with the increasing of the thickness ratio (t Al /t Al 2 O 3 ). The high δ c value means high fracture resistance. Therefore, a control of the thickness ratio t Al /t Al 2 O 3 was concerned as a key to improve the toughness and strength of the aluminized steel.

  7. Microstructure, Tensile Properties, and Corrosion Behavior of Die-Cast Mg-7Al-1Ca- xSn Alloys

    Science.gov (United States)

    Wang, Feng; Dong, Haikuo; Sun, Shijie; Wang, Zhi; Mao, Pingli; Liu, Zheng

    2018-02-01

    The microstructure, tensile properties, and corrosion behavior of die-cast Mg-7Al-1Ca- xSn ( x = 0, 0.5, 1.0, and 2.0 wt.%) alloys were studied using OM, SEM/EDS, tensile test, weight loss test, and electrochemical test. The experimental results showed that Sn addition effectively refined grains and intermetallic phases and increased the amount of intermetallic phases. Meanwhile, Sn addition to the alloys suppressed the formation of the (Mg,Al)2Ca phase and resulted in the formation of the ternary CaMgSn phase and the binary Mg2Sn phase. The Mg-7Al-1Ca-0.5Sn alloy exhibited best tensile properties at room temperature, while Mg-7Al-1Ca-1.0Sn alloy exhibited best tensile properties at elevated temperature. The corrosion resistance of studied alloys was improved by the Sn addition, and the Mg-7Al-1Ca-0.5Sn alloy presented the best corrosion resistance.

  8. Unstable propagation behavior of a ductile crack in SUS-304 stainless steel under high compliance tensile loading

    International Nuclear Information System (INIS)

    Tomoda, Yoshio

    1981-01-01

    In relation to the safe maintenance of nuclear power plants, it is necessary to prevent reactor coolant pipings from burst type failure caused by the unstable propagation of defects and cracks, such as stress corrosion cracking and fatigue cracks. In ductile materials, crack propagation is stable in tensile loading under fixed grip condition, when a specimen is controlled to deform in proportion to the increase of tensile load. However, it has been known that the instability of ductile cracks occurs after tensile load reached the maximum, especially under constant loading condition arising in the loading devices with high compliance or low tensile rigidity. In order to confirm the reliability of SUS 304 stainless pipes subjected to SCC, the crack propagation behavior was examined with the specimens having center cracks, using both testing machines with high compliance and low compliance. The instability of ductile cracks and the propagation velocity of unstable cracks were analyzed, and the calculated results were compated with the experimental results. Not only the compliance of testing machines but also the conditions of specimens affected the propagation of cracks. (Kako, I.)

  9. Construction of cryogenic testing system and tensile deformation behavior of AISI 300 series stainless steels at cryogenic temperatures

    International Nuclear Information System (INIS)

    Lee, H.M.; Nahm, S.H.; Huh, Y.H.; Lee, J.J.; Bahng, G.W.

    1990-01-01

    For practical application of cryogenic engineering, development and characterization of structural materials for use at low temperatures are essential. For these purposes, a system for mechanical testing at liquid helium temperatures was developed and it was shown that the precision and accuracy of the system met the requirements of standards for materials testing machines. Using this system, tensile deformation behavior of AISI 304,316 and 310S austenitic stainless steels at cryogenic temperatures was investigated. Tests were conducted on round, tensile specimens having a 6.25mm diameter at 4,77, and 295 K and loading rate was 0.5mm/min. Serrations were observed in all alloys at 4 K. The stress-displacement curves at 77 and 4 K showed different tendency from those at 298 K. As the testing temperature decreased, ultimate strengths of 304 and 316 were largely increased compared to the increase of yield strengths, but the increase of ultimate strength of 310S was almost the same to that of yield strength. Type 310S had the highest yield strength and the lowest tensile strength at all temperatutes. These tensile characteristics were considered to be strongly affected by austenite stability.(Author)

  10. Finite Element Modeling of Compressive and Splitting Tensile Behavior of Plain Concrete and Steel Fiber Reinforced Concrete Cylinder Specimens

    Directory of Open Access Journals (Sweden)

    Md. Arman Chowdhury

    2016-01-01

    Full Text Available Plain concrete and steel fiber reinforced concrete (SFRC cylinder specimens are modeled in the finite element (FE platform of ANSYS 10.0 and validated with the experimental results and failure patterns. Experimental investigations are conducted to study the increase in compressive and tensile capacity of cylindrical specimens made of stone and brick concrete and SFRC. Satisfactory compressive and tensile capacity improvement is observed by adding steel fibers of 1.5% volumetric ratio. A total of 8 numbers of cylinder specimens are cast and tested in 1000 kN capacity digital universal testing machine (UTM and also modeled in ANSYS. The enhancement of compressive strength and splitting tensile strength of SFRC specimen is achieved up to 17% and 146%, respectively, compared to respective plain concrete specimen. Results gathered from finite element analyses are validated with the experimental test results by identifying as well as optimizing the controlling parameters to make FE models. Modulus of elasticity, Poisson’s ratio, stress-strain behavior, tensile strength, density, and shear transfer coefficients for open and closed cracks are found to be the main governing parameters for successful model of plain concrete and SFRC in FE platform. After proper evaluation and logical optimization of these parameters by extensive analyses, finite element (FE models showed a good correlation with the experimental results.

  11. Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-12-01

    Full Text Available The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry, since vehicle crushing often happens at intermediate strain rates. Back stress hardening has been found to play an important role for this HSSS due to load transfer and strain partitioning between two phases, and a higher strain rate could cause even higher strain partitioning in the softer austenite grains, delaying the deformation instability. Deformation twins are observed in the austenite grains at all strain rates to facilitate the uniform tensile deformation. The B2 phase (FeAl intermetallic compound is less deformable at higher strain rates, resulting in easier brittle fracture in B2 particles, smaller dimple size and a higher density of phase interfaces in final fracture surfaces. Thus, more energy need be consumed during the final fracture for the experiments conducted at higher strain rates, resulting in better tensile toughness.

  12. Prediction of Tensile Behavior of UHSFRC Considering the Flow Field in the Placing Dominated by Shear Flow

    Directory of Open Access Journals (Sweden)

    Joon-Shik Moon

    2018-01-01

    Full Text Available Considering the case of fabricating a UHSFRC (ultra-high strength fiber-reinforced concrete beam with the method of one end placing and self-flowing to the other end, it was intended to simulate the variation of the fiber orientation distribution according to the flow distance and the variation of the resultant tensile behaviors. Then the validity of the simulation approach was shown by comparing the simulated results with experimental ones. A three-point bending test with a notched beam was adopted for the experiment and a finite element analysis was performed to obtain the simulated results for the bending test considering the flow-dependent tensile behavior of the UHSFRC. From the simulation for the fiber orientation distribution according to the flow distance, it could be found that the major change in the fiber orientation distribution took place within a short flow distance and most of the fibers became nearly aligned to the flow direction. After some flow distance, there was a not-so-remarkable variation in the fiber orientation distribution that could influence the tensile behavior of the composite. For this flow region, the consistent flexural test results, regardless of flow distance, demonstrate the reliability of the simulation.

  13. Prediction of Tensile Behavior of UHSFRC Considering the Flow Field in the Placing Dominated by Shear Flow.

    Science.gov (United States)

    Moon, Joon-Shik; Kang, Su-Tae

    2018-01-26

    Considering the case of fabricating a UHSFRC (ultra-high strength fiber-reinforced concrete) beam with the method of one end placing and self-flowing to the other end, it was intended to simulate the variation of the fiber orientation distribution according to the flow distance and the variation of the resultant tensile behaviors. Then the validity of the simulation approach was shown by comparing the simulated results with experimental ones. A three-point bending test with a notched beam was adopted for the experiment and a finite element analysis was performed to obtain the simulated results for the bending test considering the flow-dependent tensile behavior of the UHSFRC. From the simulation for the fiber orientation distribution according to the flow distance, it could be found that the major change in the fiber orientation distribution took place within a short flow distance and most of the fibers became nearly aligned to the flow direction. After some flow distance, there was a not-so-remarkable variation in the fiber orientation distribution that could influence the tensile behavior of the composite. For this flow region, the consistent flexural test results, regardless of flow distance, demonstrate the reliability of the simulation.

  14. Tensile behavior of unnotched and notched tungsten--copper laminar composites

    International Nuclear Information System (INIS)

    Hoffman, C.A.

    1976-06-01

    Relations were studied between the tensile strengths of unnotched and of notched, and elastic moduli of unnotched laminar sheet or foil composites and the amounts of reinforcement. Tungsten was used as the reinforcement and copper as the matrix, and the tests were run at room temperature. Three thicknesses of tungsten (i.e., 0.00254, 0.0127, and 0.0254 cm (0.001, 0.005, and 0.010 in) were used, and the nominal volume fraction of tungsten was varied from about 0.05 to 0.95. It was found that the tensile strength of the unnotched specimens could be related to the amount of reinforcement, as could the elastic moduli, and that these values could be predicted by use of the rule of mixtures. The tensile strengths of the notched laminar composites could be predicted by use of the rule of mixtures using strengths for notched constituents, provided notch effects did not predominate. (Author)

  15. Effects of niobium addition on microstructure and tensile behavior of as-cast ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangru, E-mail: cxr16@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Xu, Jie, E-mail: shuxujie@163.com [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Hu, Henry, E-mail: huh@uwindsor.ca [Department of Mechanical, Automotive and Materials Engineering University of Windsor, 401 Sunset Avenue, Windsor, Ontario, Canada N9B 3P4 (Canada); Mohrbacher, Hardy, E-mail: hm@niobelcon.net [NiobelCon bvba, Swaenebeecklaan, 2970 Schilde (Belgium); Kang, Ming, E-mail: kangming@dfcv.com.cn [Dongfeng Commercial Vehicle Co., Ltd., Wuhan 430056 (China); Zhang, Wei, E-mail: zhangwei3@citic.com [CITIC Metal Co., Ltd., Beijing 100004 (China); Guo, Aimin, E-mail: guoam@citic.com [CITIC Metal Co., Ltd., Beijing 100004 (China); Zhai, Qijie, E-mail: qjzhai@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

    2017-03-14

    The effects of niobium addition up to 0.11 wt% on the microstructure and tensile properties of as-cast ductile iron (ACDI) were investigated. Metallographic analyses by both optical microscopy (OM) and scanning electron microscopy (SEM) indicated that niobium (Nb) promoted the formation of pearlite, reduced pearlite lamellar spacing and decreased the extent of graphitization taking place in the Nb-alloyed ACDI. The nodularity and nodule counts of graphite changed insignificantly when the Nb content was less than 0.08 wt% in the ACDI. The analysis of precipitates by transmission electron microscopy (TEM) revealed that nano and micro sized (Nb, Ti)C carbides acted as nucleation site for graphites, and promoted the formation of large graphite nodules with low roundnesses as Nb content rose above 0.08 wt%. The results of tensile testing showed that the yield strength, ultimate tensile strength and elongation of the ACDI with 0.08 wt% Nb increased by 12.1%, 11.2% and 14.3% over those of the Nb-free ACDI, respectively. The optimum values of the yield strength, tensile strength and elongation of the Nb-alloyed ACDI were found to be 418 MPa, 746.0 MPa and 8.0%, respectively, at the Nb content of 0.08 wt%. The high strain hardening rates of the Nb-containing ACDIs implied that they were capable of spontaneously strengthening itself increasingly to a large extent, in response to a slight plastic deformation after yielding.

  16. Tensile behavior of orthorhombic alpha ''-titanium alloy studied by in situ X-ray diffraction

    DEFF Research Database (Denmark)

    Wang, X.D.; Lou, H.B.; Ståhl, Kenny

    2010-01-01

    are indeed due to a low stress yielding (similar to 400 MPa) followed with a significant work-hardening before necking and fracture. In this process, the [0 2 2] orientation of grains more approaches the tensile direction and the [2 0 0] moves to the transverse, causing the lattice parameter a to be shrunk...

  17. Tensile behavior of friction stir welded AA 6061-T4 aluminum alloy joints

    International Nuclear Information System (INIS)

    Heidarzadeh, A.; Khodaverdizadeh, H.; Mahmoudi, A.; Nazari, E.

    2012-01-01

    Highlights: ► Range of parameters for defect-free friction stir welded AA 6061-T4 was reached. ► A model was developed for predicting UTS and EL of friction stir welded AA 6061-T4. ► The maximum values of UTS and EL of joints were estimated by developed model. ► The optimum values of FSW process parameters were determined. -- Abstract: In this investigation response surface methodology based on a central composite rotatable design with three parameters, five levels and 20 runs, was used to develop a mathematical model predicting the tensile properties of friction stir welded AA 6061-T4 aluminum alloy joints at 95% confidence level. The three welding parameters considered were tool rotational speed, welding speed and axial force. Analysis of variance was applied to validate the predicted model. Microstructural characterization and fractography of joints were examined using optical and scanning electron microscopes. Also, the effects of the welding parameters on tensile properties of friction stir welded joints were analyzed in detail. The results showed that the optimum parameters to get a maximum of tensile strength were 920 rev/min, 78 mm/min and 7.2 kN, where the maximum of tensile elongation was obtained at 1300 rev/min, 60 mm/min and 8 kN.

  18. Strain rate dependent deformation and failure behavior of laser welded DP780 steel joint under dynamic tensile loading

    International Nuclear Information System (INIS)

    Liu, Yang; Dong, Danyang; Wang, Lei; Chu, Xi; Wang, Pengfei; Jin, Mengmeng

    2015-01-01

    Laser welded DP steel joints are used widely in the automotive industry for weight reduction. Understanding the deformation and fracture behavior of the base metal (BM) and its welded joint (WJ), especially at high strain rates, is critical for the design of vehicle structures. This paper is concerned with the effects of strain rate on the tensile properties, deformation and fracture behavior of the laser welded DP780 steel joint. Quasi-static and dynamic tensile tests were performed on the WJ and BM of the DP780 steel using an electromechanical universal testing machine and a high-speed tensile testing machine over a wide range of strain rate (0.0001–1142 s −1 ). The microstructure change and microhardness distribution of the DP780 steel after laser welding were examined. Digital image correlation (DIC) and high-speed photography were employed for the strain measurement of the DP780 WJ during dynamic tensile tests. The DP780 WJ is a heterogeneous structure with hardening in fusion zone (FZ) and inner heat-affected zone (HAZ), and softening in outer HAZ. The DP780 BM and WJ exhibit positive strain rate dependence on the YS and UTS, which is smaller at lower strain rates and becomes larger with increasing strain rate, while ductility in terms of total elongation (TE) tends to increase under dynamic loading. Laser welding leads to an overall reduction in the ductility of the DP780 steel. However, the WJ exhibits a similar changing trend of the ductility to that of the BM with respect to the strain rate over the whole strain rate range. As for the DP780 WJ, the distance of tensile failure location from the weld centerline decreases with increasing strain rate. The typical ductile failure characteristics of the DP780 BM and WJ do not change with increasing strain rate. DIC measurements reveal that the strain localization starts even before the maximum load is attained in the DP780 WJ and gradual transition from uniform strains to severely localized strains occurs

  19. Strain rate dependent deformation and failure behavior of laser welded DP780 steel joint under dynamic tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang, E-mail: liuyang@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Dong, Danyang, E-mail: dongdanyang@mail.neu.edu.cn [College of Science, Northeastern University, Shenyang 110819 (China); Wang, Lei, E-mail: wanglei@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Chu, Xi, E-mail: chuxi.ok@163.com [College of Science, Northeastern University, Shenyang 110819 (China); Wang, Pengfei, E-mail: wpf1963871400@163.com [College of Science, Northeastern University, Shenyang 110819 (China); Jin, Mengmeng, E-mail: 24401878@163.com [College of Science, Northeastern University, Shenyang 110819 (China)

    2015-03-11

    Laser welded DP steel joints are used widely in the automotive industry for weight reduction. Understanding the deformation and fracture behavior of the base metal (BM) and its welded joint (WJ), especially at high strain rates, is critical for the design of vehicle structures. This paper is concerned with the effects of strain rate on the tensile properties, deformation and fracture behavior of the laser welded DP780 steel joint. Quasi-static and dynamic tensile tests were performed on the WJ and BM of the DP780 steel using an electromechanical universal testing machine and a high-speed tensile testing machine over a wide range of strain rate (0.0001–1142 s{sup −1}). The microstructure change and microhardness distribution of the DP780 steel after laser welding were examined. Digital image correlation (DIC) and high-speed photography were employed for the strain measurement of the DP780 WJ during dynamic tensile tests. The DP780 WJ is a heterogeneous structure with hardening in fusion zone (FZ) and inner heat-affected zone (HAZ), and softening in outer HAZ. The DP780 BM and WJ exhibit positive strain rate dependence on the YS and UTS, which is smaller at lower strain rates and becomes larger with increasing strain rate, while ductility in terms of total elongation (TE) tends to increase under dynamic loading. Laser welding leads to an overall reduction in the ductility of the DP780 steel. However, the WJ exhibits a similar changing trend of the ductility to that of the BM with respect to the strain rate over the whole strain rate range. As for the DP780 WJ, the distance of tensile failure location from the weld centerline decreases with increasing strain rate. The typical ductile failure characteristics of the DP780 BM and WJ do not change with increasing strain rate. DIC measurements reveal that the strain localization starts even before the maximum load is attained in the DP780 WJ and gradual transition from uniform strains to severely localized strains

  20. Fracture and flaking off behavior of coated layer of DyBCO coated conductor under applied tensile strain

    International Nuclear Information System (INIS)

    Arai, T.; Shin, J.K.; Matsubayashi, H.; Ochiai, S.; Okuda, H.; Osamura, K.; Prusseit, W.

    2009-01-01

    The tensile behavior of the DyBa 2 Cu 3 O 7-δ (DyBCO) coated conductor with MgO buffer layer deposited on the Hastelloy C-276 substrate by inclined substrate deposition (ISD) was studied. The tensile stress-strain curve showed a flat region, characterized by the discontinuous yielding of the substrate due to the Lueders band extension from the gripped portions of the sample. In the area where the Lueders band had passed, the coating layer showed severe multiple transverse cracking due to the localized plastic deformation of the substrate. The flaking off of the coating layers took place at high applied strain, due to the buckling fracture of the coated layers in the sample width direction, accompanied by the interfacial debonding.

  1. Tensile Fracture Behavior and Failure Mechanism of Additively-Manufactured AISI 4140 Low Alloy Steel by Laser Engineered Net Shaping

    Directory of Open Access Journals (Sweden)

    Hoyeol Kim

    2017-11-01

    Full Text Available AISI 4140 powder was directly deposited on AISI 4140 wrought substrate using laser engineered net shaping (LENS to investigate the compatibility of a LENS-deposited part with the substrate. Tensile testing at room temperature was performed to evaluate the interface bond performance and fracture behavior of the test specimens. All the samples failed within the as-deposited zone, indicating that the interfacial bond is stronger than the interlayer bond inside the deposit. The fracture surfaces were analyzed using scanning electron microscopy (SEM and energy disperse X-ray spectrometry (EDS. Results show that the tensile fracture failure of the as-deposited part is primarily affected by lack-of-fusion defects, carbide precipitation, and oxide particles inclusions, which causes premature failure of the deposit by deteriorating the mechanical properties and structural integrity.

  2. The ideal tensile strength and deformation behavior of a tungsten single crystal

    International Nuclear Information System (INIS)

    Liu Yuelin; Zhou Hongbo; Zhang Ying; Jin Shuo; Lu Guanghong

    2009-01-01

    We employ first-principles total energy method based on the density functional theory with the generalized gradient approximation to investigate the ideal tensile strengths of a bcc tungsten (W) single crystal systemically. The ideal tensile strengths are shown to be 29.1, 49.2 and 37.6 GPa for bcc W in the [0 0 1], [1 1 0] and [1 1 1] directions, respectively. The [0 0 1] direction is shown to be the weakest direction due to the occurrence of structure transition at the lower strain and the [1 1 0] direction is strongest. The results can provide a useful reference for W as a PFM in the nuclear fusion Tokamak.

  3. The growth and tensile deformation behavior of the silver solid solution phase with zinc

    International Nuclear Information System (INIS)

    Wu, Jiaqi; Lee, Chin C.

    2016-01-01

    The growth of homogeneous silver solid solution phase with zinc are conducted at two different compositions. X-ray diffraction (XRD) and Scanning electron microscope/Energy dispersive X-ray spectroscopy (SEM/EDX) are carried out for phase identification and chemical composition verification. The mechanical properties of silver solid solution phase with zinc are evaluated by tensile test. The engineering and true stress vs. strain curves are presented and analyzed, with those of pure silver in comparison. According to the experimental results, silver solid solution phase with zinc at both compositions show tempered yield strength, high tensile strength and large uniform strain compared to those of pure silver. Fractography further confirmed the superior ductility of silver solid solution phase with zinc at both compositions. Our preliminary but encouraging results may pave the way for the silver based alloys to be applied in industries such as electronic packaging and structure engineering.

  4. Effect of cold work on tensile behavior of irradiated type 316 stainless steel

    International Nuclear Information System (INIS)

    Klueh, R.L.; Maziasz, P.J.

    1986-01-01

    Tensile specimens were irradiated in ORR at 250, 290, 450, and 500 0 C to produce a displacement damage of approx.5 dpa and 40 at. ppM He. Irradiation at 250 and 290 0 C caused an increase in yield stress and ultimate tensile strength and a decrease in ductility relative to unaged and thermally aged controls. The changes were greatest for the 20%-cold-worked steel and lowest for the 50%-cold-worked steel. Irradiation at 450 0 C caused a slight relative decrease in strength for all cold-worked conditions. A large decrease was observed at 500 0 C, with the largest decrease occurring for the 50%-cold-worked specimen. No bubble, void, or precipitate formation was observed for specimens examined by transmission electron microscopy (TEM). The irradiation hardening was correlated with Frank-loop and ''black-dot'' loop damage. A strength decrease at 500 0 C was correlated with dislocation network recovery. Comparison of tensile and TEM results from ORR-irradiated steel with those from steels irradiated in the High Flux Isotope Reactor and the Experimental Breeder Reactor indicated consistent strength and microstructure changes

  5. Tensile, Creep, and Fatigue Behaviors of 3D-Printed Acrylonitrile Butadiene Styrene

    Science.gov (United States)

    Zhang, Hanyin; Cai, Linlin; Golub, Michael; Zhang, Yi; Yang, Xuehui; Schlarman, Kate; Zhang, Jing

    2018-01-01

    Acrylonitrile butadiene styrene (ABS) is a widely used thermoplastics in 3D printing. However, there is a lack of thorough investigation of the mechanical properties of 3D-printed ABS components, including orientation-dependent tensile strength and creep fatigue properties. In this work, a systematic characterization is conducted on the mechanical properties of 3D-printed ABS components. Specifically, the effect of printing orientation on the tensile and creep properties is investigated. The results show that, in tensile tests, the 0° printing orientation has the highest Young's modulus of 1.81 GPa, and ultimate strength of 224 MPa. In the creep test, the 90° printing orientation has the lowest k value of 0.2 in the plastics creep model, suggesting 90° is the most creep resistant direction. In the fatigue test, the average cycle number under load of 30 N is 3796 cycles. The average cycle number decreases to 128 cycles when the load is 60 N. Using the Paris law, with an estimated crack size of 0.75 mm, and stress intensity factor is varied from 352 to 700 N√ m, the derived fatigue crack growth rate is 0.0341 mm/cycle. This study provides important mechanical property data that is useful for applying 3D-printed ABS in engineering applications.

  6. Tensile Properties and Fracture Behavior of a Powder-Thixoformed 2024Al/SiCp Composite at Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Pubo Li

    2017-10-01

    Full Text Available In the present work, the tensile properties and fracture behavior of a 2024Al composite reinforced with 10 vol % SiCp and fabricated via powder thixoforming (PT were studied at temperatures ranging from 25 °C to 300 °C with a strain rate of 0.05 s−1, as well as the PT 2024 alloy. The results indicated that the tensile strengths of both the PT materials were all decreased with increasing the temperature, but the decrease rate of the composite was smaller than that of the 2024 alloy, and the composite exhibited higher tensile strength than that of the 2024 alloy at all of the employed testing temperatures due to the strengthening role of SiCp. Increasing temperature was beneficial for enhancing the ductility of materials, and the maximum elongation was reached at 250 °C. The elongation decrease over 250 °C was attributed to the cavity formation due to the debonding of the SiCp/Al interface and the fracturing of the matrix between SiCp. The fracture of the composite at room temperature initiated from the fracture of SiCp and the debonding of the SiCp/Al interface, but that at high temperatures was dominated by void nucleation and growth in the matrix besides the interface debonding.

  7. National Postirradiation Examination Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Schulthess, Jason L

    2011-06-01

    A National Post-Irradiation-Examination (PIE) Workshop was held March 29-30, 2011, in Washington D.C., stimulated by the DOE Acting Assistant Secretary for Nuclear Energy approval on January 31, 2011 of the “Mission Need Statement for Advanced Post-Irradiation Examination Capability”. As stated in the Mission Need, “A better understanding of nuclear fuels and material performance in the nuclear environment, at the nanoscale and lower, is critical to the development of innovative fuels and materials required for tomorrow’s nuclear energy systems.” (2011) Developing an advanced post-irradiation capability is the most important thing we can do to advance nuclear energy as an option to meeting national energy goals. Understanding the behavior of fuels and materials in a nuclear reactor irradiation environment is the limiting factor in nuclear plant safety, longevity, efficiency, and economics. The National PIE Workshop is part of fulfilling or addressing Department of Energy (DOE) missions in safe and publically acceptable nuclear energy. Several presentations were given during the opening of the workshop. Generally speaking, these presentations established that we cannot continue to rely on others in the world to provide the capabilities we need to move forward with nuclear energy technology. These presentations also generally identified the need for increased microstructural understanding of fuels and materials to be coupled with modeling and simulation, and increased accessibility and infrastructure to facilitate the interaction between national laboratories and participating organizations. The overall results of the work of the presenters and panels was distilled into four primary needs 1. Understanding material changes in the extreme nuclear environment at the nanoscale. Nanoscale studies have significant importance due to the mechanisms that cause materials to degrade, which actually occur on the nanoscale. 2. Enabling additional proficiency in

  8. Aging effects on fracture behavior of 63Sn37Pb eutectic solder during tensile tests under the SEM

    International Nuclear Information System (INIS)

    Ding Ying; Wang Chunqing; Li Mingyu; Bang Hansur

    2004-01-01

    This study investigates the influence of aging treatment on fracture behavior of Sn-Pb eutectic solder alloys at different loading rate regime during tensile tests under the scanning electron microscope. In high homologous temperature, the solder exhibit the creep behavior that could be confirmed through the phenomena of grain boundary sliding (GBS) to both as-cast and aged specimens. Owing to the large grain scale after high temperature storage, boundary behavior was limited to some extent for the difficulty in grain rotation and boundary migration. Instead, drastic intragranular deformation occurred. Also, the phase coarsening weakened the combination between lead-rich phase and tin matrix. Consequently, surface fragmentation was detected for the aged specimens. Furthermore, the fracture mechanism changed from intergranular dominated to transgranular dominated with increasing loading rate to both specimens during early stage

  9. Genetic alterations as determined by quantitative morphological, viability and social behavioral traits in postirradiation generations of an inbred strain of the platyfish, Xiphophorus maculatus (Guenther)(Pisces: Poecliidae), induced by 1000 R of X-rays to spermatogonia and oogonia

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J.H.; Heinrich, W. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.))

    Spermatogonia and oogonia were X-irradiated with 258 mC/kg in neonatal platyfish. This procedure corresponds to an exposure of immature spermatogonia and oogonia. The postirradiation (PI) F/sub 2/ generation was compared with controls of the same origin regarding viability characters (brood size, postnatal mortality, and sex ratio), quantitative morphological (number of vertebrae, body proportions) and social behavioral traits (cohesiveness of both sexes, male sexual and agonistic behavior patterns). Each of 5 pairs of F/sub 2/ fish were used as the founders for a one-year lasting population experiment in which the fish had been subjected to either mutation pressure through derivation from irradiated spermatogonia and oogonia as mentioned above or to selection pressure through predation by the convict cichlid, Cichlasoma nigrofasciatum, or to a combination of both in order to compare the outcome of this experiment with that of a control population. The PI F/sub 2/ exhibited a higher mortality rate than the controls. A unidirectional shift of the mean values of the quantitative morphological characters towards a more compact fish was observed in the postirradiation generations. The social cohesiveness of PI F/sub 2/ was higher than that of the controls. Male sexual activity was enhanced in PI F/sub 2/, and there was a similar trend to higher intraspecific aggressiveness among PI F/sub 2/ males. The single effects of mutation and selection pressures were beneficial in so far as the number of individuals and the biomass were enhanced, while a combination of both was deleterious endangering the population to extinction. Contrary to expectation, the coefficient of variation for the quantitative morphological traits was higher in the controls than in the Pi F/sub 2/.

  10. Microstructural basis and crack growth theories for post-irradiation ductility loss in Nimonic PE16

    International Nuclear Information System (INIS)

    Chang, A.L.

    1982-01-01

    A study has been carried out to investigate the degradation of postirradiation ductility at reactor temperatures in Nimonic PE16, a Fe-Cr-Ni-based precipitation-hardened superalloy. Fractographic and microstructural investigations show that the grain matrix is capable of deformation and does not limit the postirradiation tensile ductility. Grain-boundary helium bubbles formed during neutron irradiation seem to be crack nucleation sites under stress. Growth and coalescence of these microcracks under stress lead to intergranular fracture. A rigid-grain fracture model is shown to be able to correlate the observed microstructures with most features of the mechanical properties, except the strain rate dependence of the ductility. By incorporating the interactions between diffusion and plastic deformation, a plastic-grain fracture model has been developed which can explain all postirradiation tensile ductility data quantitatively. 13 references

  11. Dynamic tensile behavior of electron beam additive manufactured Ti6Al4V

    International Nuclear Information System (INIS)

    Rodriguez, O.L.; Allison, P.G.; Whittington, W.R.; Francis, D.K.; Rivera, O.G.; Chou, K.; Gong, X.; Butler, T.M.; Burroughs, J.F.

    2015-01-01

    High rate and quasi-static tensile experiments examined strain rate dependence on flow stress and strain hardening of additive manufactured Ti6Al4V. Variations on strain-hardening coefficient indicate that the rate of thermal softening is greater than strain hardening during plastic deformation. Strain rate sensitivity calculations within the plastic strain regime suggest changes in deformation mechanisms. Fractography revealed cup-and-cone fracture for quasi-static samples and shear mechanisms for high rate samples. As-deposited microstructure consisted of bimodal α+β with the presence of secondary martensitic phase

  12. Dynamic tensile behavior of electron beam additive manufactured Ti6Al4V

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, O.L. [Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States); Allison, P.G., E-mail: pallison@eng.ua.edu [Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States); Whittington, W.R.; Francis, D.K. [Department of Mechanical Engineering, Mississippi State University, Starkville, MS 35759 (United States); Rivera, O.G.; Chou, K.; Gong, X. [Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States); Butler, T.M. [Department of Metallurgical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States); Burroughs, J.F. [Geotechnical & Structures Laboratory, US Army ERDC, Vicksburg, MS 39180 (United States)

    2015-08-12

    High rate and quasi-static tensile experiments examined strain rate dependence on flow stress and strain hardening of additive manufactured Ti6Al4V. Variations on strain-hardening coefficient indicate that the rate of thermal softening is greater than strain hardening during plastic deformation. Strain rate sensitivity calculations within the plastic strain regime suggest changes in deformation mechanisms. Fractography revealed cup-and-cone fracture for quasi-static samples and shear mechanisms for high rate samples. As-deposited microstructure consisted of bimodal α+β with the presence of secondary martensitic phase.

  13. Ageing sintered silver: Relationship between tensile behavior, mechanical properties and the nanoporous structure evolution

    Energy Technology Data Exchange (ETDEWEB)

    Gadaud, Pascal; Caccuri, Vincenzo; Bertheau, Denis [Institut Pprime, Dept. Phys. Mech. Mat., UPR CNRS 3346, ENSMA, Université de Poitiers, 1 av. Clément Ader, Téléport 2, 86961 Futuroscope – Chasseneuil (France); Carr, James [HMXIF, Materials Science Centre, The University of Manchester, M13 9PL (United Kingdom); Milhet, Xavier, E-mail: xavier.milhet@ensma.fr [Institut Pprime, Dept. Phys. Mech. Mat., UPR CNRS 3346, ENSMA, Université de Poitiers, 1 av. Clément Ader, Téléport 2, 86961 Futuroscope – Chasseneuil (France)

    2016-07-04

    Silver pastes sintering is a potential candidate for die bonding in power electronic modules. The joints, obtained by sintering, exhibit a significant pore fraction thus reducing the density of the material compared to bulk silver. This was shown to alter drastically the mechanical properties (Young's modulus, yield strength and ultimate tensile stress) at room temperature. While careful analysis of the microstructure has been reported for the as-sintered material, little is known about its quantitative evolution (pores and grains) during thermal ageing. To address this issue, sintered bulk specimens and sintered joints were aged either under isothermal conditions (125 °C up to 1500 h) or under thermal cycling (between −40 °C/+125 °C with 30 min dwell time at each temperature for 2400 cycles). Under these conditions, it is shown that the density of the material does not change but the sub-micron porosity evolves towards a broader size distribution, consistent with Oswald ripening. It is also shown that only the step at 125 °C during the non-isothermal ageing is responsible for the microstructure evolution: isothermal ageing at high temperature can be regarded as a useful tool to perform accelerated ageing tests. Tensile properties are investigated as both a function of ageing time and a function of density. It is shown that the elastic properties do not evolve with the ageing time unlike the plastic properties. This is discussed as a function of the material microstructure evolution.

  14. Tensile behavior of Cu50Zr50 metallic glass nanowire with a B2 crystalline precipitate

    Science.gov (United States)

    Sepulveda-Macias, Matias; Amigo, Nicolas; Gutierrez, Gonzalo

    2018-02-01

    A molecular dynamics study of the effect of a single B2-CuZr precipitate on the mechanical properties of Cu50Zr50 metallic glass nanowires is presented. Four different samples are considered: three with a 2, 4 and 6 nm radii precipitate and a precipitate-free sample. These systems are submitted to uniaxial tensile test up to 25% of strain. The interface region between the precipitate and the glass matrix has high local atomic shear strain, activating shear transformation zones, which concentrates in the neighborhood of the precipitate. The plastic regime is dominated by necking, and no localized shear band is observed for the samples with a 4 and 6 nm radii precipitate. In addition, the yield stress decreases as the size of the precipitate increases. Regarding the precipitate structure, no martensitic phase transformation is observed, since neither the shear band hit the precipitate nor the stress provided by the tensile test is enough to initiate the transformation. It is concluded that, in contrast to the case when multiple precipitates are present in the sample, a single precipitate concentrates the shear strain around its surface, eventually causing the failure of the nanowire.

  15. Tensile deformation behavior and deformation twinning of an equimolar CoCrFeMnNi high-entropy alloy

    Energy Technology Data Exchange (ETDEWEB)

    Joo, S.-H.; Kato, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Jang, M.J.; Moon, J. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Tsai, C.W.; Yeh, J.W. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Kim, H.S., E-mail: hskim@postech.ac.kr [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of); Center for High Entropy Alloys, Pohang University of Science and Technology, Pohang 37673 (Korea, Republic of)

    2017-03-24

    The tensile deformation and strain hardening behaviors of an equimolar CoCrFeMnNi high-entropy alloy (HEA) were investigated and compared with low and medium entropy equiatomic alloys (LEA and MEA). The HEA had a lower yield strength than the MEA because the addition of Mn weakens solid solution hardening in the HEA. However, deformation twinning induced the multiple stage strain hardening behavior of the HEA and enhanced strength and elongation. Using tensile-interrupted electron backscatter diffraction analysis, geometrically necessary dislocations were observed as plume-shaped features in grain interior, and a considerable texture was characterized, which is typical of face centered cubic metals. Moreover, the relationship between favorably oriented grains and twinning in the HEA bore a clear resemblance to the same tendency in TWIP steels. The thickness of the twin bundles was less than 100 nm. A high density of stacking defects was found in the nanotwins. Nano twinning and stacking faults were found to contribute to the remarkable mechanical properties. Deformation induced twinning not only demonstrated the dynamic Hall-Petch effect but also changed dislocation cell substructures into microband structures.

  16. In-Plane Anisotropy in Mechanical Behavior and Microstructural Evolution of Commercially Pure Titanium in Tensile and Cyclic Loading

    Science.gov (United States)

    Sinha, Subhasis; Gurao, N. P.

    2017-12-01

    Tensile and cyclic deformation behavior of three samples oriented at 0, 45, and 90 deg to the rolling direction in the rolling direction-transverse direction (RD-TD) plane of cold-rolled and annealed plate of commercially pure titanium is studied in the present investigation. The sample along the RD (R0) shows the highest strength but lowest ductility in monotonic tension. Although ultimate tensile strength (UTS) and elongation of samples along 45 and 90 deg to the RD (R45 and R90, respectively) are similar, the former has significantly higher yield strength than the latter, indicating different strain-hardening behavior. It is found that the R90 sample exhibits the highest monotonic ductility as well as fatigue life. This is attributed to a higher propensity for twinning in this sample with the presence of multiple variants and twin intersections. Cyclic life is also influenced by the high tendency for detwinning of contraction twins in this orientation. Elastoplastic self-consistent (EPSC) simulations of one-cycle tension-compression load reversal indicate that the activity of pyramidal 〈 c + a〉 slip and extension twinning oscillates during cyclic loading that builds up damage in a cumulative manner, leading to failure in fatigue.

  17. Hot Tensile and Fracture Behavior of 35CrMo Steel at Elevated Temperature and Strain Rate

    Directory of Open Access Journals (Sweden)

    Zhengbing Xiao

    2016-08-01

    Full Text Available To better understand the tensile deformation and fracture behavior of 35CrMo steel during hot processing, uniaxial tensile tests at elevated temperatures and strain rates were performed. Effects of deformation condition on the flow behavior, strain rate sensitivity, microstructure transformation, and fracture characteristic were characterized and discussed. The results indicated that the flow stress was sensitive to the deformation condition, and fracture occurs immediately after the peak stress level is reached, especially when the temperature is low or the strain rate is high. The strain rate sensitivity increases with the deformation temperature, which indicates that formability could improve at high temperatures. Photographs showing both the fracture surfaces and the matrix near the fracture section indicated the ductile nature of the material. However, the fracture mechanisms varied according to the deformation condition, which influences the dynamic recrystallization (DRX condition, and the DRX was accompanied by the formation of voids. For samples deformed at high temperatures or low strain rates, coalescence of numerous voids formed in the recrystallized grains is responsible for fracture, while at high strain rates or low temperatures, the grains rupture mainly by splitting because of cracks formed around the inclusions.

  18. The effect of strain-rate on the tensile and compressive behavior of graphene reinforced epoxy/nanocomposites

    International Nuclear Information System (INIS)

    Shadlou, Shahin; Ahmadi-Moghadam, Babak; Taheri, Farid

    2014-01-01

    Highlights: • The epoxy/graphene nanocomposites were studied at various strain rates. • The variations in constitutive stress–strain response were scrutinized. • Positive reinforcing attributes of graphene diminished at higher strain rates. • Graphene particles have higher efficiency under compression loading than tension. • A new modification factor for Halpin–Tsai model was proposed. - Abstract: The effect of strain rate on the mechanical behavior of epoxy reinforced with graphene nanoplatelets (GNPs) is investigated. Nanocomposites containing various amounts of GNP are prepared and tested at four different strain rates (0.01, 0.1, 1 and 10/s) under compressive and tensile loading regimes. The results show that incorporation of GNP highly affects the behavior of epoxy. The fracture surfaces of tensile specimens are also investigated using scanning electron microscopy (SEM) to discern the surface features and dispersion state of GNP. Finally, the predictive capability of some of the available models for evaluating the strength of nanocomposites are assessed and compared against the experimental results. Moreover, a modification factor to the widely used Halpin–Tsai model is proposed to improve the accuracy of the model when evaluating the Young’s modulus of nanocomposites at various strain rates

  19. Effect of heat treatment on the elevated temperature tensile and fracture toughness behavior of Alloy 718 weldments

    International Nuclear Information System (INIS)

    Mills, W.J.

    1980-05-01

    The effect of heat treatment on the tensile and fracture toughness properties of Alloy 718 weldments was characterized at room temperature and elevated temperatures. The two heat treatments employed during this investigation were the convectional (ASTM A637) precipitation treatment and a modified treatment designed to improve the toughness of Alloy 718 welds. Weldments were also examined in the as-welded condition. The fracture toughness behavior of the Alloy 718 weldments was determined at 24, 427 and 538 degree C using both linear-elastic (K Ic ) and elastic-plastic (J Ic ) fracture mechanics concepts. Metallographic and electron fractographic examination of Alloy 718 weld fracture surfaces revealed that differences in fracture toughness behavior for the as-welded, conventional and modified conditions were associated with variations in the weld microstructure. 28 refs., 16 figs., 4 tabs

  20. Facile Synthesis and Tensile Behavior of TiO2 One-Dimensional Nanostructures

    Directory of Open Access Journals (Sweden)

    Li Shu-you

    2009-01-01

    Full Text Available Abstract High-yield synthesis of TiO2 one-dimensional (1D nanostructures was realized by a simple annealing of Ni-coated Ti grids in an argon atmosphere at 950 °C and 760 torr. The as-synthesized 1D nanostructures were single crystalline rutile TiO2 with the preferred growth direction close to [210]. The growth of these nanostructures was enhanced by using catalytic materials, higher reaction temperature, and longer reaction time. Nanoscale tensile testing performed on individual 1D nanostructures showed that the nanostructures appeared to fracture in a brittle manner. The measured Young’s modulus and fracture strength are ~56.3 and 1.4 GPa, respectively.

  1. Tensile behavior of Inconel alloy X-750 in air and vacuum at elevated temperatures

    International Nuclear Information System (INIS)

    Taplin, D.M.R.; Mukherjee, A.K.; Pandey, M.C.

    1984-01-01

    The hot tensile properties of Inconel alloy X-750 have been investigated experimentally at 700 C in air and vacuum at strain rates varying from 10 to the -7th to 1.2 x 10 to the -6th per s. The strength and ductile characteristics of the specimens tested in vacuum are found to be better than those tested in air. In air, a ductility minimum is observed at 625 C, whereas in vacuum, significant improvements in creep ductility are observed at 575 and 625 C, with the ductility minimum shifting from 625 to 700 C. It is shown that the creep ductility of the specimens tested in air is largely determined by the following two competing processes: (1) deformation-assisted oxygen diffusion and (2) grain boundary migration. 20 references

  2. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    International Nuclear Information System (INIS)

    Bang, Hyejin; Cho, Chongdu

    2017-01-01

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  3. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Hyejin; Cho, Chongdu [Inha University, Incheon (Korea, Republic of)

    2017-08-15

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  4. Recovery behavior of high purity cubic SiC polycrystals by post-irradiation annealing up to 1673 K after low temperature neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Idris, Mohd Idzat, E-mail: idzat.i.aa@m.titech.ac.jp [Department of Nuclear Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 Japan (Japan); The National University of Malaysia, School of Applied Physics, Faculty of Science and Technology, 43600 Bangi Selangor (Malaysia); Yamazaki, Saishun; Yoshida, Katsumi; Yano, Toyohiko [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 Japan (Japan)

    2015-10-15

    Two kinds of high purity cubic (β) SiC polycrystals, PureBeta-SiC and CVD-SiC, were irradiated in the BR2 reactor (Belgium) up to a fluence of 2.0–2.5 × 10{sup 24} (E > 0.1 MeV) at 333–363 K. Changes in macroscopic lengths were examined by post-irradiation thermal annealing using a precision dilatometer up to 1673 K with a step-heating method. The specimen was held at each temperature step for 6 h and the change in length of the specimen was recorded during each isothermal annealing step from 373 K to 1673 K with 50 K increments. The recovery curves were analyzed with the first order model, and rate constants at each annealing step were obtained. Recovery of defects, induced by neutron irradiation in high purity β-SiC, has four stages of different activation energies. At 373–573 K, the activation energy of PureBeta-SiC and CVD-SiC was in the range of 0.17–0.24 eV and 0.12–0.14 eV; 0.002–0.04 eV and 0.006–0.04 eV at 723–923 K; 0.20–0.27 eV and 0.26–0.31 eV at 923–1223 K; and 1.37–1.38 eV and 1.26–1.29 eV at 1323–1523 K, respectively. Below ∼1223 K the recombination occurred possibly for closely positioned C and Si Frenkel pairs, and no long range migration is deemed essential. Nearly three-fourths of recovery, induced by neutron irradiation, occur by this mechanism. In addition, at 1323–1523 K, recombination of slightly separated C Frenkel pairs and more long-range migration of Si interstitials may have occurred for PureBeta-SiC and CVD-SiC specimens. Migration of both vacancies may be restricted up to ∼1523 K. Comparing to hexagonal α-SiC, high purity β-SiC recovered more quickly in the lower annealing temperature range of less than 873 K, in particular less than 573 K. - Highlights: • Two kinds of high purity cubic (β) SiC polycrystals were irradiated. • Macroscopic lengths were examined by post-irradiation thermal annealing. • The recovery curves were analyzed with first order model.

  5. Analysis of surface roughening behavior of 6063 aluminum alloy by tensile testing of a trapezoidal uniaxial specimen

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); Wang, Xiaosong, E-mail: hitxswang@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001 (China); Yuan, Shijian [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001 (China)

    2016-08-30

    To determine the quantitative relationship between surface roughness and strain, the surface roughening behavior of a 6063 aluminum alloy tube was examined by tensile testing of a trapezoidal uniaxial specimen, that can provide a continuous strain distribution after tensile deformation. The surface roughness was measured using a laser scanning confocal microscope to reflect the degree of roughening. The microstructure and surface morphology were examined using electron back-scattered diffraction and in-situ scanning electron microscopy to determine the grain orientation and surface topography evolution. The surface roughness increased with strain when the strain was less than 0.067 and then decreased slightly, with a maximum surface roughness of 23.73 µm. Inhomogeneous deformation at the grain boundaries and inside the grains was enhanced with increasing strain, resulting in an increase of surface roughness when the strain was below a critical value. As the strain increased, a greater number of slip systems contributed to the further deformation. Thus, the strain became more homogeneous, and accordingly, the surface roughness slightly decreased.

  6. Tensile behavior of porous scaffolds made from poly(para phenylene) - biomed 2013.

    Science.gov (United States)

    Dirienzo, Amy L; Yakacki, Christopher M; Safranski, David L; Frick, Carl P

    2013-01-01

    The goal of this study was to fabricate and mechanically characterize a high-strength porous polymer scaffold for potential use as an orthopedic device. Poly(para-phenylene) (PPP) is an excellent candidate due to its exceptional strength and stiffness and relative inertness, but has never been explicitly investigated for use as a biomedical device. PPP has strength values 3 to 10 times higher and an elastic modulus nearly an order of magnitude higher than traditional polymers such as poly(methyl methacrylate) (PMMA), polycaprolactone (PCL), ultra-high molecular weight polyethylene (UHMWPE), and polyurethane (PU) and is significantly stronger and stiffer than polyetheretherketone (PEEK). By utilizing PPP we can overcome the mechanical limitations of traditional porous polymeric scaffolds since the outstanding stiffness of PPP allows for a highly porous structure appropriate for osteointegration that can match the stiffness of bone (100-250 MPa), while maintaining suitable mechanical properties for soft-tissue fixation. Porous samples were manufactured by powder sintering followed by particle leaching. The pore volume fraction was systematically varied from 50–80 vol% for a pore sizes from150-500 µm, as indicated by previous studies for optimal osteointegration. The tensile modulus of the porous samples was compared to the rule of mixtures, and closely matches foam theory up to 70 vol%. The experimental modulus for 70 vol% porous samples matches the stiffness of bone and contains pore sizes optimal for osteointegration.

  7. Assessment of microstructure and tensile behavior of continuous drive friction welded titanium tubes

    International Nuclear Information System (INIS)

    Palanivel, R.; Dinaharan, I.; Laubscher, R.F.

    2017-01-01

    Friction welding process has been applied to join Grade 2 titanium alloy tubes of outer diameter 60 mm and wall thickness 3.9 mm. In this research work, five different friction times (24, 28, 32, 36 and 40 s) were used to evaluate the ultimate tensile strength (UTS) and microstructure of welded tubes. Recording of the process parameters during welding was done. Optical microscopy, electron back scattered diffraction and transmission electron microscopy were used to study the microstructure. The results showed that the friction time had a significant influence on the microstructure and UTS. The rate of deformation increased with friction time and refined the grains in the weld zone. Coarse grain structure was observed from the center of the weld zone towards the flash. Identical grain structure was observed in the heat affected zone (HAZ) and the parent metal. It was found that a maximum joint efficiency of 98.3% was achieved at a friction time of 32 s.The details of microhardness, failure location and fracture surface of the welded tubes were reported.

  8. Assessment of microstructure and tensile behavior of continuous drive friction welded titanium tubes

    Energy Technology Data Exchange (ETDEWEB)

    Palanivel, R., E-mail: rpalanivelme@gmail.com; Dinaharan, I., E-mail: dinaweld2009@gmail.com; Laubscher, R.F., E-mail: rflaubscher@uj.ac.za

    2017-02-27

    Friction welding process has been applied to join Grade 2 titanium alloy tubes of outer diameter 60 mm and wall thickness 3.9 mm. In this research work, five different friction times (24, 28, 32, 36 and 40 s) were used to evaluate the ultimate tensile strength (UTS) and microstructure of welded tubes. Recording of the process parameters during welding was done. Optical microscopy, electron back scattered diffraction and transmission electron microscopy were used to study the microstructure. The results showed that the friction time had a significant influence on the microstructure and UTS. The rate of deformation increased with friction time and refined the grains in the weld zone. Coarse grain structure was observed from the center of the weld zone towards the flash. Identical grain structure was observed in the heat affected zone (HAZ) and the parent metal. It was found that a maximum joint efficiency of 98.3% was achieved at a friction time of 32 s.The details of microhardness, failure location and fracture surface of the welded tubes were reported.

  9. Relationship between local deformation behavior and crystallographic features of as-quenched lath martensite during uniaxial tensile deformation

    International Nuclear Information System (INIS)

    Michiuchi, M.; Nambu, S.; Ishimoto, Y.; Inoue, J.; Koseki, T.

    2009-01-01

    Electron backscattering diffraction patterns were used to investigate the relationship between local deformation behavior and the crystallographic features of as-quenched lath martensite of low-carbon steel during uniform elongation in tensile tests. The slip system operating during the deformation up to a strain of 20% was estimated by comparing the crystal rotation of each martensite block after deformation of 20% strain with predictions by the Taylor and Sachs models. The results indicate that the in-lath-plane slip system was preferentially activated compared to the out-of-lath-plane system up to this strain level. Further detailed analysis of crystal rotation at intervals of approximately 5% strain confirmed that the constraint on the operative slip system by the lath structure begins at a strain of 8% and that the local strain hardening of the primary slip systems occurred at approximately 15% strain.

  10. Postirradiation examination of beryllium pebbles

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1998-01-01

    Postirradiation examinations of COBRA-1A beryllium pebbles irradiated in the EBR-II fast reactor at neutron fluences which generated 2700--3700 appm helium have been performed. Measurements included density change, optical microscopy, scanning electron microscopy, and transmission electron microscopy. The major change in microstructure is development of unusually shaped helium bubbles forming as highly non-equiaxed thin platelet-like cavities on the basal plane. Measurement of the swelling due to cavity formation was in good agreement with density change measurements

  11. Effect of strain rate and stress triaxiality on tensile behavior of Titanium alloy Ti-10-2-3 at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bobbili, Ravindranadh, E-mail: ravindranadh@dmrl.drdo.in; Madhu, Vemuri

    2016-06-14

    In this study, Split hopkinson tension bar (SHTB) has been employed to investigate the dynamic tensile flow behavior of Ti-10-2-3 alloy at high strain rates and elevated temperatures. The combined effect of stress triaxiality, strain rate and temperature and on the tensile behavior of the alloy was evaluated. Johnson-Cook (J-C) constitutive and fracture models were developed based on high strain rate tensile data. A modified Johnson–Cook model was established and proved to have high accuracy. A comparative assessment has been done to confirm the accuracy of modified J–C model based on finite element method (FEM). The improved model provides better description on the influence of equivalent plastic strain rate and temperature on the plastic flow. The simulation results proved to be in good agreement with the experimental data. The fracture surfaces of specimens tested under various strain rates and temperatures were studied under scanning electron microscopy (SEM).

  12. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route.

    Science.gov (United States)

    Hangai, Yoshihiko; Kamada, Hiroto; Utsunomiya, Takao; Kitahara, Soichiro; Kuwazuru, Osamu; Yoshikawa, Nobuhiro

    2014-03-21

    Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%-78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT) observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE) analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  13. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2014-03-01

    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  14. Void coalescence and fracture behavior of notched and un-notched tensile tested specimens in fine grain dual phase steel

    Energy Technology Data Exchange (ETDEWEB)

    Saeidi, N., E-mail: navidsae@gmail.com [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Ashrafizadeh, F.; Niroumand, B. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Forouzan, M.R.; Mohseni mofidi, S. [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Barlat, F. [Materials Mechanics Laboratory (MML), Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology POSTECH, San 31 Hyoja-dong, Nam-gu, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

    2015-09-17

    Due to growing global concern about the environmental issues, steel developers have been forced by automobile makers to produce more efficient steel grades with high strength to weight ratios along with high crashworthiness performance. In order to find deficiencies of the existing steels and develop superior steel products, detailed understanding of deformation and damage behavior in the existing steels is needed. In the present research, deformation and damage evolution during room temperature uniaxial tensile test of a modern high strength Dual Phase Steel, i.e. DP780, were studied. Detailed scanning electron microscopy (SEM) examination of the microstructures of notched and un-notched tensile fractured specimens revealed that in notched specimen, plastic deformation was concentrated more within the notched region. Therefore, much higher reduction in thickness with a high reduction gradient occurred in this region, In the un-notched specimen, however, plastic deformation was more uniformly distributed in larger parts of the gauge length, and therefore, thickness reduction happened with a lower gradient. Although geometric notch on the specimen did not change the void nucleation and growth mechanisms, the kinetics of these phenomena was influenced. On the other hand, voids linkage mechanism tended to change from void coalescence in the un-notched specimen to void sheeting in the notched specimen. Moreover, three different models developed by Brown & Embury (BM), Thomason and Pardoen were employed to predict the final fracture strain. It was revealed that, BM model showed much more accurate predictions for the studied DP steel in comparison with those of Thomason and Pardoens’ models.

  15. Void coalescence and fracture behavior of notched and un-notched tensile tested specimens in fine grain dual phase steel

    International Nuclear Information System (INIS)

    Saeidi, N.; Ashrafizadeh, F.; Niroumand, B.; Forouzan, M.R.; Mohseni mofidi, S.; Barlat, F.

    2015-01-01

    Due to growing global concern about the environmental issues, steel developers have been forced by automobile makers to produce more efficient steel grades with high strength to weight ratios along with high crashworthiness performance. In order to find deficiencies of the existing steels and develop superior steel products, detailed understanding of deformation and damage behavior in the existing steels is needed. In the present research, deformation and damage evolution during room temperature uniaxial tensile test of a modern high strength Dual Phase Steel, i.e. DP780, were studied. Detailed scanning electron microscopy (SEM) examination of the microstructures of notched and un-notched tensile fractured specimens revealed that in notched specimen, plastic deformation was concentrated more within the notched region. Therefore, much higher reduction in thickness with a high reduction gradient occurred in this region, In the un-notched specimen, however, plastic deformation was more uniformly distributed in larger parts of the gauge length, and therefore, thickness reduction happened with a lower gradient. Although geometric notch on the specimen did not change the void nucleation and growth mechanisms, the kinetics of these phenomena was influenced. On the other hand, voids linkage mechanism tended to change from void coalescence in the un-notched specimen to void sheeting in the notched specimen. Moreover, three different models developed by Brown & Embury (BM), Thomason and Pardoen were employed to predict the final fracture strain. It was revealed that, BM model showed much more accurate predictions for the studied DP steel in comparison with those of Thomason and Pardoens’ models

  16. Mechanical behaviors of multi-filament twist superconducting strand under tensile and cyclic loading

    Science.gov (United States)

    Wang, Xu; Li, Yingxu; Gao, Yuanwen

    2016-01-01

    The superconducting strand, serving as the basic unit cell of the cable-in-conduit-conductors (CICCs), is a typical multi-filament twist composite which is always subjected to a cyclic loading under the operating condition. Meanwhile, the superconducting material Nb3Sn in the strand is sensitive to strain frequently relating to the performance degradation of the superconductivity. Therefore, a comprehensive study on the mechanical behavior of the strand helps understanding the superconducting performance of the strained Nb3Sn strands. To address this issue, taking the LMI (internal tin) strand as an example, a three-dimensional structural finite element model, named as the Multi-filament twist model, of the strand with the real configuration of the LMI strand is built to study the influences of the plasticity of the component materials, the twist of the filament bundle, the initial thermal residual stress and the breakage and its evolution of the filaments on the mechanical behaviors of the strand. The effective properties of superconducting filament bundle with random filament breakage and its evolution versus strain are obtained based on the damage theory of fiber-reinforced composite materials proposed by Curtin and Zhou. From the calculation results of this model, we find that the occurrence of the hysteresis loop in the cyclic loading curve is determined by the reverse yielding of the elastic-plastic materials in the strand. Both the initial thermal residual stress in the strand and the pitch length of the filaments have significant impacts on the axial and hysteretic behaviors of the strand. The damage of the filaments also affects the axial mechanical behavior of the strand remarkably at large axial strain. The critical current of the strand is calculated by the scaling law with the results of the Multi-filament twist model. The predicted results of the Multi-filament twist model show an acceptable agreement with the experiment.

  17. Static tensile deformation behavior of a lean duplex stainless steel studied by in situ neutron diffraction and synchrotron radiation white x-rays

    International Nuclear Information System (INIS)

    Tsuchida, Noriyuki; Kawahata, Taiji; Ishimaru, Eiichiro; Takahashi, Akihiko; Suzuki, Hiroshi; Shobu, Takahisa

    2013-01-01

    To investigate the tensile deformation behavior of a lean duplex stainless steel (S32101) from the viewpoints of plastic deformability among phases or grains, we performed static tensile tests, in situ neutron diffraction, and white x-ray diffraction experiments at room temperature. In the static tensile tests, the S32101 steel displayed a larger uniform elongation and a better tensile strength-uniform elongation balance than a commercial SUS329J4L duplex stainless steel. A larger uniform elongation of S32101 is associated with the macroscopic work hardening behavior that a work hardening rate higher than the flow stress can maintain up until high true strains. From the experimental results of synchrotron radiation white x-ray diffraction experiments, the hard phase of S32101 was changed from the ferrite (α) phase to austenite (γ) one during tensile deformation. This led to a larger stress partitioning between the phases at the latter stage of deformation. From the experimental results of in situ neutron diffraction, it was found that the stress partitioning of the γ phase in the S32101 was the largest among the present results. Therefore, the larger work hardening rate of S32101 can be explained by the large stress partitioning of the γ phase, that between γ and α phases and γ volume fraction. (author)

  18. Tensile and fracture behavior of boron and carbon modified Ti-15-3 alloys in aged conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, R., E-mail: rajdeepsarkar@dmrl.drdo.in [Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500058 (India); Ghosal, P.; Nandy, T.K. [Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500058 (India); Ray, K.K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2016-02-22

    This work illustrates the effect of boron and carbon addition on the mechanical behavior of a beta Ti alloy, Ti–15V–3Cr–3Al–3Sn (Ti-15-3), in differently aged conditions. The alloys were prepared by consumable vacuum arc melting followed by forging and hot rolling. These were subsequently solution treated and aged at different temperatures above 500 °C for 8 h. Standard tensile and plane strain fracture toughness tests were carried out to understand the mechanical behavior of the alloys and its correlation with the microstructural features characterized by scanning and transmission electron microscopy. Both the boron- and the carbon-containing alloys exhibit improved strength with comparable elongation to failure values as compared to the base Ti-15-3 alloy. The presence of TiB and TiC precipitates in a matrix of fine α with β results in lower fracture toughness (K{sub IC}) in the boron- and carbon-containing alloys as compared to the base alloy. However, at higher aging temperatures K{sub IC} improves due to more tortuous crack path because of the presence of coarse α-phase. An empirical relationship has been proposed correlating K{sub IC} with the volume fraction, size and interspacing of α in these alloys.

  19. Improved tensile and buckling behavior of defected carbon nanotubes utilizing boron nitride coating – A molecular dynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Badjian, H.; Setoodeh, A.R., E-mail: setoodeh@sutech.ac.ir

    2017-02-15

    Synthesizing inorganic nanostructures such as boron nitride nanotubes (BNNTs) have led to immense studies due to their many interesting functional features such as piezoelectricity, high temperature resistance to oxygen, electrical insulation, high thermal conductivity and very long lengths as physical features. In order to utilize the superior properties of pristine and defected carbon nanotubes (CNTs), a hybrid nanotube is proposed in this study by forming BNNTs surface coating on the CNTs. The benefits of such coating on the tensile and buckling behavior of single-walled CNTs (SWCNTs) are illustrated through molecular dynamics (MD) simulations of the resulted nanostructures during the deformation. The AIREBO and Tersoff-Brenner potentials are employed to model the interatomic forces between the carbon and boron nitride atoms, respectively. The effects of chiral indices, aspect ratio, presence of mono-vacancy defects and coating dimension on coated/non-coated CNTs are examined. It is demonstrated that the coated defective CNTs exhibit remarkably enhanced ultimate strength, buckling load capacity and Young's modulus. The proposed coating not only enhances the mechanical properties of the resulted nanostructure, but also conceals it from few external factors impacting the behavior of the CNT such as humidity and high temperature.

  20. Floating liquid bridge tensile behavior: Electric-field-induced Young's modulus measurements

    Science.gov (United States)

    Teschke, Omar; Mendez Soares, David; Valente Filho, Juracyr Ferraz

    2013-12-01

    A floating bridge is formed spontaneously when high voltage is applied to polar fluids in two capillary tubes that were in contact and then separated. This bridge bends under its own weight, and its bending profile was used to calculate its Young's modulus. For electric field intensities of ˜106 V/m, water bridges exhibit viscoelastic behavior, with Young's moduli of ˜24 MPa; dimethylsulfoxide (DMSO) bridges exhibited Young's moduli of ˜60 kPa. The scheme devised to measure the voltage drop across the water bridge for high voltages applied between the electrodes shows that the bulk water resistance decreases with increasing voltage.

  1. Tensile and fatigue behaviors of printed Ag thin films on flexible substrates

    International Nuclear Information System (INIS)

    Sim, Gi-Dong; Won, Sejeong; Lee, Soon-Bok

    2012-01-01

    Flexible electronics using nanoparticle (NP) printing has been highlighted as a key technology enabling eco-friendly, low-cost, and large-area fabrication. For NP-based printing to be used as a successive alternative to photolithography and vacuum deposition, stretchability and long term reliability must be considered. This paper reports the stretchability and fatigue behavior of 100 nm thick NP-based silver thin films printed on polyethylene-terephthalate substrate and compares it to films deposited by electron-beam evaporation. NP-based films show stretchability and fatigue life comparable to evaporated films with intergranular fracture as the dominant failure mechanism.

  2. Tensile and fatigue behaviors of printed Ag thin films on flexible substrates

    Science.gov (United States)

    Sim, Gi-Dong; Won, Sejeong; Lee, Soon-Bok

    2012-11-01

    Flexible electronics using nanoparticle (NP) printing has been highlighted as a key technology enabling eco-friendly, low-cost, and large-area fabrication. For NP-based printing to be used as a successive alternative to photolithography and vacuum deposition, stretchability and long term reliability must be considered. This paper reports the stretchability and fatigue behavior of 100 nm thick NP-based silver thin films printed on polyethylene-terephthalate substrate and compares it to films deposited by electron-beam evaporation. NP-based films show stretchability and fatigue life comparable to evaporated films with intergranular fracture as the dominant failure mechanism.

  3. Mesoscopic Modeling and Simulation of the Dynamic Tensile Behavior of Concrete

    DEFF Research Database (Denmark)

    Pedersen, Ronnie; Simone, A.; Sluys, L. J.

    2013-01-01

    of the most significant constitutive model parameters on global and local response. Different distributions and shapes of the aggregate grains are tested. Three model parameter sets, corresponding to different moisture conditions, are employed in the analysis of two specimens in which the applied loading rate......We present a two-dimensional mesoscopic finite element model for simulating the rate- and moisture-dependent material behavior of concrete. The idealized mesostructure consists of aggregate grains surrounded by an interfacial transition zone embedded in the bulk material. We examine the influence...

  4. Tensile flow and work-hardening behavior of a Ti-modified austenitic stainless steel

    International Nuclear Information System (INIS)

    Sivaprasad, P.V.; Venugopal, S.; Venkadesan, S.

    1997-01-01

    The flow-stress data of a 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel in the temperature range 300 to 1,023 K was analyzed in terms of Ludwigson and Voce equations. The parameters of these equations were critically examined with respect to the effect of Ti/C ratio and test temperature. It was found that the Ludwigson equation described the flow behavior adequately up to the test temperature of 923 K, whereas the Voce equation could be employed in the full temperature range. The peaks/plateaus observed in the variation of these parameters as a function of temperature in the intermediate temperature range have been identified as one of the manifestations of dynamic strain aging (DSA). Also, the variation of these parameters with temperature clearly could bring out the different domains of DSA observed in this alloy. The work-hardening analysis of the flow-stress data revealed that in the DSA regime, the onset of stage III hardening is athermal

  5. Microstructure and Tensile Behavior of Al8Co17Cr17Cu8Fe17Ni33 (at.%) High-Entropy Alloy

    Science.gov (United States)

    Daoud, H. M.; Manzoni, A.; Völkl, R.; Wanderka, N.; Glatzel, U.

    2013-12-01

    Microstructure evolution and tensile behavior of the high-entropy alloy Al8Co17Cr17Cu8Fe17Ni33 (at.%) are investigated at room temperature and at 500°C in the as-cast state and under different heat-treatment conditions. Detailed microstructural characterizations are carried out using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The equilibrium phase evolution as a function of temperature was calculated using the Thermo-Calc software (Thermo-Calc Software, Stockholm, Sweden) integrated with TTNi-7 database. The observed majority phase is a face-centered cubic solid solution for all tested specimens. Tensile ductility at room temperature and at elevated temperature is enhanced by heat treatment at 1150°C. An embrittlement phenomenon has been observed after a heat treatment at 700°C resulting in significant degradation in tensile properties.

  6. Post-irradiation examinations and theoretical analyses of the fuel and fuel pin behavior of innovative systems; Bestrahlungsnachuntersuchungen und modelltheoretische Analysen zum Brennstoff- und Brennstabverhalten innovativer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, W.; Freund, D.; Geithoff, D.; Heck, M.; Jacobi, O.; Steiner, H.; Weimar, P.

    1995-08-01

    For the development of LMR cladding materials an irradiation test was performed in the KNK II reactor between 1986 and 1991. It demonstrated that a temperature gradient in the cladding has no observable effect on swelling behavior. PIEs of transient experiments in the Petten HFR have shown no significant cladding deformations. (orig.)

  7. Tensile behavior of RAFM alloys after neutron irradiation of up to 16.3 dpa between 250 and 450 °C

    Energy Technology Data Exchange (ETDEWEB)

    Materna-Morris, E., E-mail: edeltraud.materna-morris@kit.edu; Schneider, H.-C., E-mail: hans-christian.schneider@kit.edu; Möslang, A., E-mail: anton.moeslang@kit.edu

    2014-12-15

    Tensile specimen of steel EUROFER97 and other alloys on the basis of RAFM steels such, as OPTIFER and F82H alloys, and Ga3X were irradiated and post-examined during a neutron irradiation program of up to 16.3 dpa between 250 and 450 °C in the HFR (High Flux Reactor) in the Netherlands. These tensile results were compared with former irradiation programs, with lower neutron doses of up to 0.8 and 2.4 dpa to quantify the difference in tensile strengthening. The average increase of tensile strength was in a range of 300 MPa between 0.8 and 16.3 dpa at temperatures of 250–300 °C. This behavior can be correlated with irradiation-induced changes in the microstructure. Most of the hardening can be attributed to dislocation loops, point defects or small precipitates as observed in boron-free alloys as F82H mod. and EUROFER97. Whereas the hardening in boron-containing alloys OPTIFER alloys and Ga3X can be correlated in addition with the combination of helium bubbles. At the highest irradiation and test temperature at 450 °C, all tensile data of all investigated materials were in the range of those of non-irradiated and irradiated material due to thermal aging effects.

  8. Tensile behavior of RAFM alloys after neutron irradiation of up to 16.3 dpa between 250 and 450 °C

    International Nuclear Information System (INIS)

    Materna-Morris, E.; Schneider, H.-C.; Möslang, A.

    2014-01-01

    Tensile specimen of steel EUROFER97 and other alloys on the basis of RAFM steels such, as OPTIFER and F82H alloys, and Ga3X were irradiated and post-examined during a neutron irradiation program of up to 16.3 dpa between 250 and 450 °C in the HFR (High Flux Reactor) in the Netherlands. These tensile results were compared with former irradiation programs, with lower neutron doses of up to 0.8 and 2.4 dpa to quantify the difference in tensile strengthening. The average increase of tensile strength was in a range of 300 MPa between 0.8 and 16.3 dpa at temperatures of 250–300 °C. This behavior can be correlated with irradiation-induced changes in the microstructure. Most of the hardening can be attributed to dislocation loops, point defects or small precipitates as observed in boron-free alloys as F82H mod. and EUROFER97. Whereas the hardening in boron-containing alloys OPTIFER alloys and Ga3X can be correlated in addition with the combination of helium bubbles. At the highest irradiation and test temperature at 450 °C, all tensile data of all investigated materials were in the range of those of non-irradiated and irradiated material due to thermal aging effects

  9. Study of twinning behavior of powder metallurgy Ti-Si alloy by interrupted in-situ tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Ye, X.X., E-mail: ye-xiaoxin@jwri.osaka-u.ac.jp [Joining and Welding Institute (JWRI), Osaka University (Japan); Imai, H.; Shen, J.H.; Chen, B. [Joining and Welding Institute (JWRI), Osaka University (Japan); Han, G.Q. [College of Materials Science and Engineering, Beijing University of Technology (China); Umeda, J.; Kondoh, K. [Joining and Welding Institute (JWRI), Osaka University (Japan)

    2017-01-02

    Twinning mechanism of powder metallurgy Ti-Si alloy was investigated by interrupted in-situ tensile tests. Extension twins {10−12}<10-1-1> in the fine-grained Ti-Si alloy were found in the uniform deformation period, but no twinning in the coarse pure Ti. Three deformation twinning nucleation mechanisms were proposed: i) local stress concentration by neighboured slip incompatibility, ii) slip/twin oriented relationship in the parent grain and iii) slip/twin transfer by high Luster-Morris oriented relationship. The interior back-stress state, grains rotation and dislocations pile-up drove the occurrence of detwinning phenomenon. Silicon-facilitation twinning verified the hypothesis that the substitutional Si solutes affected the core structures and thus the mobility of screw dislocations. Enhanced driving force and decreased energy barrier of nucleation in the micro/atomic scale were further proposed in the twinning activation. It was expected to deepen the understanding of twinning/detwinning behaviors and supply direct evidences building immature twinning mechanism. In-depth understanding about the relationship among the processing, mechanical properties and microstructure of Ti alloy was facilitated in the present work.

  10. Microstructural evolution and the variation of tensile behavior after aging heat treatment of precipitation hardened martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jong-Ho, E-mail: jongho.shin@doosan.com [Casting and Forging Technology Development Team, Doosan Heavy Industries and Construction, 22 Doosanvolvo-ro, Changwon 642-792 (Korea, Republic of); Jeong, JaeSuk [Materials and Manufacturing Development Team, Doosan Heavy Industries and Construction, 22 Doosanvolvo-ro, Changwon 642-792 (Korea, Republic of); Lee, Jong-Wook [Casting and Forging Technology Development Team, Doosan Heavy Industries and Construction, 22 Doosanvolvo-ro, Changwon 642-792 (Korea, Republic of)

    2015-01-15

    The effects of aging temperature on the microstructural evolution and the tensile behavior of precipitation hardened martensitic steel were investigated. Microscopic analysis using transmission electron microscope (TEM) was combined with the microstructural analysis using the synchrotron X-ray diffraction (XRD) to characterize the microstructural evolution with aging temperature. Peak hardness was obtained by precipitation of the Ni{sub 3}Al ordered phase. After aging at temperature range from 420 to 590 °C, spherical Ni{sub 3}Al precipitates and ellipsoidal M{sub 23}C{sub 6} carbides were observed within laths and at lath boundaries, respectively. Strain hardening behavior was analyzed with Ludwik equation. It is observed that the plastic strain regimes can be divided into two different stages by a rapid increase in strain hardening followed by a comparatively lower increase. At the first strain hardening stage, the aged specimen exhibited higher strain hardening exponent than the as-quenched specimen, and the exponent in the aged specimen was not changed considerably with increasing aging temperature. It is revealed that the strain hardening exponents at the first and the second stages were associated with the Ni{sub 3}Al precipitates and the domain size representing the coherent scattering area, respectively. - Highlights: • All of aged specimen exhibited higher strain hardening exponent than the as-quenched specimen at the first stage. • The value of strain hardening exponent in the aged specimen was nearly constant with aging temperature. • Ni{sub 3}Al precipitation dominantly influenced to the increase of strain hardening exponent at the first strain hardening stage. • Domain size was associated with strain hardening exponent at the second strain hardening stage.

  11. Microstructural evolution and the variation of tensile behavior after aging heat treatment of precipitation hardened martensitic steel

    International Nuclear Information System (INIS)

    Shin, Jong-Ho; Jeong, JaeSuk; Lee, Jong-Wook

    2015-01-01

    The effects of aging temperature on the microstructural evolution and the tensile behavior of precipitation hardened martensitic steel were investigated. Microscopic analysis using transmission electron microscope (TEM) was combined with the microstructural analysis using the synchrotron X-ray diffraction (XRD) to characterize the microstructural evolution with aging temperature. Peak hardness was obtained by precipitation of the Ni 3 Al ordered phase. After aging at temperature range from 420 to 590 °C, spherical Ni 3 Al precipitates and ellipsoidal M 23 C 6 carbides were observed within laths and at lath boundaries, respectively. Strain hardening behavior was analyzed with Ludwik equation. It is observed that the plastic strain regimes can be divided into two different stages by a rapid increase in strain hardening followed by a comparatively lower increase. At the first strain hardening stage, the aged specimen exhibited higher strain hardening exponent than the as-quenched specimen, and the exponent in the aged specimen was not changed considerably with increasing aging temperature. It is revealed that the strain hardening exponents at the first and the second stages were associated with the Ni 3 Al precipitates and the domain size representing the coherent scattering area, respectively. - Highlights: • All of aged specimen exhibited higher strain hardening exponent than the as-quenched specimen at the first stage. • The value of strain hardening exponent in the aged specimen was nearly constant with aging temperature. • Ni 3 Al precipitation dominantly influenced to the increase of strain hardening exponent at the first strain hardening stage. • Domain size was associated with strain hardening exponent at the second strain hardening stage

  12. Microstructure and Strain Rate-Dependent Tensile Deformation Behavior of Fiber Laser-Welded Butt Joints of Dual-Phase Steels

    Science.gov (United States)

    Liu, Yang; Dong, Danyang; Han, Zhiqiang; Yang, Zhibin; Wang, Lu; Dong, Qingwei

    2018-05-01

    The microstructure and tensile deformation behavior of the fiber laser-welded similar and dissimilar dual-phase (DP) steel joints over a wide range of strain rates from 10-3 to 103 s-1 were investigated for the further applications on the lightweight design of vehicles. The high strain rate dynamic tensile deformation process and full-field strain distribution of the base metals and welded joints were examined using the digital image correlation method and high-speed photography. The strain rate effects on the stress-strain responses, tensile properties, deformation, and fracture behavior of the investigated materials were analyzed. The yield stress (YS) and ultimate tensile strength (UTS) of the dissimilar DP780/DP980 welded joints were lying in-between those of the DP780 and DP980 base metals, and all materials exhibited positive strain rate dependence on the YS and UTS. Owing to the microstructure heterogeneity, the welded joints showed relatively lower ductility in terms of total elongation (TE) than those of the corresponding base metals. The strain localization started before the maximum load was reached, and the strain localization occurred earlier during the whole deformation process with increasing strain rate. As for the dissimilar welded joint, the strain localization tended to occur in the vicinity of the lowest hardness value across the welded joint, which was in the subcritical HAZ at the DP780 side. As the strain rate increased, the typical ductile failure characteristic of the investigated materials did not change.

  13. Microstructure and Strain Rate-Dependent Tensile Deformation Behavior of Fiber Laser-Welded Butt Joints of Dual-Phase Steels

    Science.gov (United States)

    Liu, Yang; Dong, Danyang; Han, Zhiqiang; Yang, Zhibin; Wang, Lu; Dong, Qingwei

    2018-04-01

    The microstructure and tensile deformation behavior of the fiber laser-welded similar and dissimilar dual-phase (DP) steel joints over a wide range of strain rates from 10-3 to 103 s-1 were investigated for the further applications on the lightweight design of vehicles. The high strain rate dynamic tensile deformation process and full-field strain distribution of the base metals and welded joints were examined using the digital image correlation method and high-speed photography. The strain rate effects on the stress-strain responses, tensile properties, deformation, and fracture behavior of the investigated materials were analyzed. The yield stress (YS) and ultimate tensile strength (UTS) of the dissimilar DP780/DP980 welded joints were lying in-between those of the DP780 and DP980 base metals, and all materials exhibited positive strain rate dependence on the YS and UTS. Owing to the microstructure heterogeneity, the welded joints showed relatively lower ductility in terms of total elongation (TE) than those of the corresponding base metals. The strain localization started before the maximum load was reached, and the strain localization occurred earlier during the whole deformation process with increasing strain rate. As for the dissimilar welded joint, the strain localization tended to occur in the vicinity of the lowest hardness value across the welded joint, which was in the subcritical HAZ at the DP780 side. As the strain rate increased, the typical ductile failure characteristic of the investigated materials did not change.

  14. Effects of Temperature and Strain Rate on Tensile Deformation Behavior of 9Cr-0.5Mo-1.8W-VNb Ferritic Heat-Resistant Steel

    Science.gov (United States)

    Guo, Xiaofeng; Weng, Xiaoxiang; Jiang, Yong; Gong, Jianming

    2017-09-01

    A series of uniaxial tensile tests were carried out at different strain rate and different temperatures to investigate the effects of temperature and strain rate on tensile deformation behavior of P92 steel. In the temperature range of 30-700 °C, the variations of flow stress, average work-hardening rate, tensile strength and ductility with temperature all show three temperature regimes. At intermediate temperature, the material exhibited the serrated flow behavior, the peak in flow stress, the maximum in average work-hardening rate, and the abnormal variations in tensile strength and ductility indicates the occurrence of DSA, whereas the sharp decrease in flow stress, average work-hardening rate as well as strength values, and the remarkable increase in ductility values with increasing temperature from 450 to 700 °C imply that dynamic recovery plays a dominant role in this regime. Additionally, for the temperature ranging from 550 to 650 °C, a significant decrease in flow stress values is observed with decreasing in strain rate. This phenomenon suggests the strain rate has a strong influence on flow stress. Based on the experimental results above, an Arrhenius-type constitutive equation is proposed to predict the flow stress.

  15. Precipitation behaviors, texture and tensile properties of an extruded Mg-7Y-1Nd-0.5Zr (wt%) alloy bar with large cross-section

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Guoliang, E-mail: shigl@grinm.com; Zhang, Kui; Li, Xinggang; Li, Yongjun; Ma, Minglong; Yuan, Jiawei

    2017-02-08

    Precipitation behaviors, texture and tensile properties of an extruded Mg-7Y-1Nd-0.5Zr (wt%) (WE71) alloy bar with large cross-section of 230 mm×140 mm were investigated by hardness test, tensile test, optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD) macro-texture measurement. The bar was manufactured industrially through a procedure of “multi-direction forging (MDF)+extrusion+on-line quenching+T5 aging”. Totally different age-hardening behaviors are shown during T5 aging at 200 and 235 °C. In the first 100 h, T5 aging at 235 °C brings about 13% increases in hardness, while T5 aging at 200 °C results in 47% increase. During T5 aging at 200 °C, β′ precipitates homogeneously nucleate within the matrix with high number density; however, during T5 aging at 235 °C, β′ precipitates heterogeneously nucleate on discrete and sparse dislocations, resulting in chain-like arrangement of β′ precipitates with broad precipitate free zones in matrix. XRD macro-texture measurement illustrates that basal texture intensity of WE71 bar is much weaker than Mg-8Al-0.5Zn-0.15Mn (wt%) (AZ80) bar; the maximum basal texture intensities in the outer (O) and center (C) of WE71 bar are all about 3, while those of AZ80 bar are 17 and 14, respectively. EBSD micro-texture measurement demonstrates that the maximum texture intensities of C and O are 5.3 and 3.5, respectively. O has higher tensile properties than C because there are more un-dynamic-recrystallization (un-DRX) grains and thus larger average grain size in C. While stretching at room temperature (RT), extrusion direction (ED) in O has the best tensile properties, i.e. ultimate tensile strength (R{sub m})=368 MPa, elongation (A)=5%, and normal direction (ND) in C has the lowest tensile properties, i.e. R{sub m}=255 MPa, A=2%. While stretching at 200 °C, strength does not degrade much; ED in O still has

  16. Finite Element Modeling of Compressive and Splitting Tensile Behavior of Plain Concrete and Steel Fiber Reinforced Concrete Cylinder Specimens

    OpenAIRE

    Chowdhury, Md. Arman; Islam, Md. Mashfiqul; Ibna Zahid, Zubayer

    2016-01-01

    Plain concrete and steel fiber reinforced concrete (SFRC) cylinder specimens are modeled in the finite element (FE) platform of ANSYS 10.0 and validated with the experimental results and failure patterns. Experimental investigations are conducted to study the increase in compressive and tensile capacity of cylindrical specimens made of stone and brick concrete and SFRC. Satisfactory compressive and tensile capacity improvement is observed by adding steel fibers of 1.5% volumetric ratio. A tot...

  17. Tensile and charpy impact properties of irradiated reduced-activation ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Tensile tests were conducted on eight reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on the steels irradiated to 26-29 dpa. Irradiation was in the Fast Flux Test Facility at 365{degrees}C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15-17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20000 h at 365{degrees}C. Thermal aging had little effect on the tensile behavior or the ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in the upper-shelf energy (USE). After {approx}7 dpa, the strength of the steels increased and then remained relatively unchanged through 26-29 dpa (i.e., the strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness, as measured by an increase in DBTT and a decrease in the USE, remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels were the most irradiation resistant.

  18. Temperature Effects on Tensile and Compressive Mechanical Behaviors of C-S-H Structure via Atomic Simulation

    Directory of Open Access Journals (Sweden)

    Hao Xin

    2017-01-01

    Full Text Available An atomic scale model of amorphous calcium silicate hydrate (C-S-H with Ca/Si ratio of 1.67 is constructed. Effects of temperature on mechanical properties of C-S-H structure under tensile and compressive loading in the layered direction are investigated via molecular dynamics simulations. Results from present simulations show that (1 the tensile strength and Young’s modulus of C-S-H structure significantly decrease with the increase of the temperature; (2 the water layer plays an important role in the mechanical properties of C-S-H structure; (3 the compressive strength is stronger than tensile strength, which corresponds with the characteristic of cement paste.

  19. The effect of strain rate and temperature on the elevated temperature tensile flow behavior of service-exposed 2.25Cr-1Mo steel

    International Nuclear Information System (INIS)

    Girish Shastry, C.; Parameswaran, P.; Mathew, M.D.; Bhanu Sankara Rao, K.; Mannan, S.L.

    2007-01-01

    The elevated temperature tensile flow behavior of service-exposed 2.25Cr-1Mo steel has been critically examined with respect to strain rate sensitivity (m) and apparent activation energy (Q) for tensile deformation. The predominant role of forest dislocations in determining the relative flow response at true plastic strains greater than 0.01 is inferred from the profile of 'm' against flow stress. The variation of 'm' with temperature and strain is discussed based on the kinetics of dislocation generation and recovery. The decrease in Q with the increase in strain rate or temperature is attributed to the increase in recovery processes like dislocation annihilation and subcell/subgrain formation. This suggestion has been supported by transmission electron microscopy

  20. Influence of Aging Products on Tensile Deformation Behavior of Al-0.62 mass%Mg-0.32 mass%Si Alloy

    DEFF Research Database (Denmark)

    Akiyoshi, Ryutaro; Ikeda, Ken-ichi; Hata, Satoshi

    2015-01-01

    mechanism, by estimating the Orowan stress and considering crystal structure of beta '' precipitates. In contrast, the aged alloys with Mg-Si clusters showed excellent performance of uniform elongation due to large work hardening compared to those of the alloy with beta '' precipitates. Dislocations......Tensile tests and microstructural observations were carried out to investigate the influence of aging products on tensile deformation behavior of Al-0.62 mass. Mg-0.32 mass-Si alloy. Solution-treated alloys were aged to form needle-like beta ''. precipitates or Mg-Si clusters. The aged alloy...... with beta '' precipitates showed higher yield stress than that with Mg-Si clusters. Transmission electron microscopy observations revealed that the beta '' precipitates pinned dislocations. It was suggested that the strengthening types of the alloy with beta '' precipitates were both Orowan and cutting...

  1. Effect of Bi modification treatment on microstructure, tensile properties, and fracture behavior of cast Al-Mg2Si metal matrix composite

    Directory of Open Access Journals (Sweden)

    Wu Xiaofeng

    2013-01-01

    Full Text Available Bi has a good modification effect on the hypoeutectic Al-Si alloy, and the morphology of eutectic Si changes from coarse acicular to fine fibrous. Based on the similarity between Mg2Si and Si phases in crystalline structure and crystallization process, the present study investigated the effects of different concentrations of Bi on the microstructure, tensile properties, and fracture behavior of cast Al-15wt.%Mg2Si in-situ metal matrix composite. The results show that the addition of the proper amount of Bi has a significant modification effect on both primary and eutectic Mg2Si in the Al-15wt.%Mg2Si composite. With an increase in Bi content from 0 to 1wt.%, the morphology of the primary Mg2Si is changed from irregular or dendritic to polyhedral shape; and its average particle size is significantly decreased from 70 to 6 μm. Moreover, the morphology of the eutectic Mg2Si phase is altered from flake-like to very short fibrous or dot-like. When the Bi addition exceeds 4.0wt.%, the primary Mg2Si becomes coarse again. However, the eutectic Mg2Si still exhibits the modified morphology. Tensile tests reveal that the Bi addition can improve the tensile strength and ductility of the material. Compared with those of the unmodified composite, the ultimate tensile strength and percentage elongation after fracture with 1.0wt.% Bi increase 51.2% and 100%, respectively. At the same time, the Bi addition changes the fracture behavior from brittle to ductile.

  2. Postirradiation Testing Laboratory (327 Building)

    International Nuclear Information System (INIS)

    Kammenzind, D.E.

    1997-01-01

    A Standards/Requirements Identification Document (S/RID) is the total list of the Environment, Safety and Health (ES and H) requirements to be implemented by a site, facility, or activity. These requirements are appropriate to the life cycle phase to achieve an adequate level of protection for worker and public health and safety, and the environment during design, construction, operation, decontamination and decommissioning, and environmental restoration. S/RlDs are living documents, to be revised appropriately based on change in the site's or facility's mission or configuration, a change in the facility's life cycle phase, or a change to the applicable standards/requirements. S/RIDs encompass health and safety, environmental, and safety related safeguards and security (S and S) standards/requirements related to the functional areas listed in the US Department of Energy (DOE) Environment, Safety and Health Configuration Guide. The Fluor Daniel Hanford (FDH) Contract S/RID contains standards/requirements, applicable to FDH and FDH subcontractors, necessary for safe operation of Project Hanford Management Contract (PHMC) facilities, that are not the direct responsibility of the facility manager (e.g., a site-wide fire department). Facility S/RIDs contain standards/requirements applicable to a specific facility that are the direct responsibility of the facility manager. S/RlDs are prepared by those responsible for managing the operation of facilities or the conduct of activities that present a potential threat to the health and safety of workers, public, or the environment, including: Hazard Category 1 and 2 nuclear facilities and activities, as defined in DOE 5480.23. Selected Hazard Category 3 nuclear, and Low Hazard non-nuclear facilities and activities, as agreed upon by RL. The Postirradiation Testing Laboratory (PTL) S/RID contains standards/ requirements that are necessary for safe operation of the PTL facility, and other building/areas that are the direct

  3. Postirradiation Testing Laboratory (327 Building)

    Energy Technology Data Exchange (ETDEWEB)

    Kammenzind, D.E.

    1997-05-28

    A Standards/Requirements Identification Document (S/RID) is the total list of the Environment, Safety and Health (ES and H) requirements to be implemented by a site, facility, or activity. These requirements are appropriate to the life cycle phase to achieve an adequate level of protection for worker and public health and safety, and the environment during design, construction, operation, decontamination and decommissioning, and environmental restoration. S/RlDs are living documents, to be revised appropriately based on change in the site`s or facility`s mission or configuration, a change in the facility`s life cycle phase, or a change to the applicable standards/requirements. S/RIDs encompass health and safety, environmental, and safety related safeguards and security (S and S) standards/requirements related to the functional areas listed in the US Department of Energy (DOE) Environment, Safety and Health Configuration Guide. The Fluor Daniel Hanford (FDH) Contract S/RID contains standards/requirements, applicable to FDH and FDH subcontractors, necessary for safe operation of Project Hanford Management Contract (PHMC) facilities, that are not the direct responsibility of the facility manager (e.g., a site-wide fire department). Facility S/RIDs contain standards/requirements applicable to a specific facility that are the direct responsibility of the facility manager. S/RlDs are prepared by those responsible for managing the operation of facilities or the conduct of activities that present a potential threat to the health and safety of workers, public, or the environment, including: Hazard Category 1 and 2 nuclear facilities and activities, as defined in DOE 5480.23. Selected Hazard Category 3 nuclear, and Low Hazard non-nuclear facilities and activities, as agreed upon by RL. The Postirradiation Testing Laboratory (PTL) S/RID contains standards/ requirements that are necessary for safe operation of the PTL facility, and other building/areas that are the direct

  4. High-Temperature Tensile Behaviors of Base Metal and Electron Beam-Welded Joints of Ni-20Cr-9Mo-4Nb Superalloy

    Science.gov (United States)

    Gupta, R. K.; Anil Kumar, V.; Sukumaran, Arjun; Kumar, Vinod

    2018-05-01

    Electron beam welding of Ni-20Cr-9Mo-4Nb alloy sheets was carried out, and high-temperature tensile behaviors of base metal and weldments were studied. Tensile properties were evaluated at ambient temperature, at elevated temperatures of 625 °C to 1025 °C, and at strain rates of 0.1 to 0.001 s-1. Microstructure of the weld consisted of columnar dendritic structure and revealed epitaxial mode of solidification. Weld efficiency of 90 pct in terms of strength (UTS) was observed at ambient temperature and up to an elevated temperature of 850 °C. Reduction in strength continued with further increase of test temperature (up to 1025 °C); however, a significant improvement in pct elongation is found up to 775 °C, which was sustained even at higher test temperatures. The tensile behaviors of base metal and weldments were similar at the elevated temperatures at the respective strain rates. Strain hardening exponent `n' of the base metal and weldment was 0.519. Activation energy `Q' of base metal and EB weldments were 420 to 535 kJ mol-1 determined through isothermal tensile tests and 625 to 662 kJ mol-1 through jump-temperature tensile tests. Strain rate sensitivity `m' was low ( 775 °C) is attributed to the presence of recrystallized grains. Up to 700 °C, the deformation is through slip, where strain hardening is predominant and effect of strain rate is minimal. Between 775 °C to 850 °C, strain hardening is counterbalanced by flow softening, where cavitation limits the deformation (predominantly at lower strain rate). Above 925 °C, flow softening is predominant resulting in a significant reduction in strength. Presence of precipitates/accumulated strain at high strain rate results in high strength, but when the precipitates were coarsened at lower strain rates or precipitates were dissolved at a higher temperature, the result was a reduction in strength. Further, the accumulated strain assisted in recrystallization, which also resulted in a reduction in strength.

  5. Anisotropic behavior studies of aluminum alloy 5083-H0 using a micro-tensile test stage in a FEG-SEM

    CSIR Research Space (South Africa)

    Motsi, GT

    2016-02-01

    Full Text Available stream_source_info Motsi_18197_2016.pdf.txt stream_content_type text/plain stream_size 1246 Content-Encoding UTF-8 stream_name Motsi_18197_2016.pdf.txt Content-Type text/plain; charset=UTF-8 Materials Science... & Engineering A, vol. 656: 266-274 Anisotropic behavior studies of aluminum alloy 5083-H0 using a micro-tensile test stage in a FEG-SEM Motsi GT Shongwe MB Sono TJ Olubambi PA ABSTRACT: The plastic anisotropic characteristics of aluminum alloy 5083-H...

  6. Postirradiation examination results for the Irradiation Effects Test IE-5

    International Nuclear Information System (INIS)

    Cook, T.F.; Ploger, S.A.; Hobbins, R.R.

    1978-03-01

    The results are presented of the postirradiation examination of four pressurized water reactor type fuel rods which were tested in-pile under a fast power ramp and film boiling operation during Irradiation Effects (IE) Test 5. The major objectives of this test were to evaluate the effects of simulated fission products on fuel rod behavior during a fast power ramp, to determine the effects of high initial internal pressure on a fuel rod during film boiling, and to assess fuel rod property changes that occur during film boiling in a fuel rod with previously irradiated cladding. The overall condition of the rods and changes that occurred in fuel and cladding as a result of the power ramp and film boiling operation, as determined from the postirradiation examination, are reported and analyzed. Effects of the simulated fission products on fuel rod behavior during a power ramp are discussed. The effect of high internal pressure on rod behavior during film boiling is evaluated. Cladding temperatures are estimated at various axial and circumferential locations. Cladding embrittlement by oxidation is also assessed

  7. Microstructural evolution and tensile behavior of Ti{sub 2}AlNb alloys based α{sub 2}-phase decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: gackmol@163.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Zeng, Weidong, E-mail: zengwd@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Dong; Zhu, Bin; Zheng, Youping [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Liang, Xiaobo [Beijing Iron & Steel Research Institute, Beijing 100081 (China)

    2016-04-26

    The formation mechanism of the fine plate-like O-phases within α{sub 2}-phases and tensile behavior of an isothermally forged Ti–22Al–25Nb (at%) orthorhombic alloy at 1040 °C during heat treatment were investigated. The investigation indicated that the alloys were heat-treated in O+B2 phase region after α{sub 2}+B2 phase region isothermally forging, the equiaxed α{sub 2}-phase was not stable and decomposed into O+α{sub 2} phases. The α{sub 2} phases formed during isothermal forging process have higher concentration of Nb and begun to decompose during O+B2 phase region heat treatment. And then the α{sub 2} phases separated into Niobium-lean and Niobium-rich regions through the Niobium diffusion: α{sub 2}→α{sub 2} (Nb-lean)+O (Nb-rich). Nb-rich regions with composition similar to Ti{sub 2}AlNb transformed to the O-phase, while the Nb-lean regions remained untransformed and retained the α{sub 2}-phase. The deformation behavior and fracture mechanism of Ti–22Al–25Nb alloy at room temperature were discussed. The deformation behavior and microstructural evolution of this alloy at different temperatures and stain rates were also investigated using uniaxial tensile test.

  8. Grain growth behavior and high-temperature high-strain-rate tensile ductility of iridium alloy DOP-26

    International Nuclear Information System (INIS)

    McKamey, C.G.; Gubbi, A.N.; Lin, Y.; Cohron, J.W.; Lee, E.H.; George, E.P.

    1998-04-01

    This report summarizes results of studies conducted to date under the Iridium Alloy Characterization and Development subtask of the Radioisotope Power System Materials Production and Technology Program to characterize the properties of the new-process iridium-based DOP-26 alloy used for the Cassini space mission. This alloy was developed at Oak Ridge National Laboratory (ORNL) in the early 1980's and is currently used by NASA for cladding and post-impact containment of the radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for interplanetary spacecraft. Included within this report are data generated on grain growth in vacuum or low-pressure oxygen environments; a comparison of grain growth in vacuum of the clad vent set cup material with sheet material; effect of grain size, test temperature, and oxygen exposure on high-temperature high-strain-rate tensile ductility; and grain growth in vacuum and high-temperature high-strain-rate tensile ductility of welded DOP-26. The data for the new-process material is compared to available old-process data

  9. Influence of aging treatment on deformation behavior of 96.5Sn3.5Ag lead-free solder alloy during in situ tensile tests

    International Nuclear Information System (INIS)

    Ding, Ying; Wang, Chunqing; Tian, Yanhong; Li, Mingyu

    2007-01-01

    This study investigates the influence of aging treatment on deformation behavior of 96.5Sn3.5Ag eutectic solder alloys with lower strain rate ( -3 s -1 ) during tensile tests under the scanning electron microscope. Results showed that because of the existence of Ag 3 Sn intermetallic particles and the special microstructure of β-Sn phases in Sn3.5Ag solder, grain boundary sliding was not the dominant mechanism any longer for this Pb-free solder. While the interaction of dislocations with the relatively rigid Ag 3 Sn particles began to dominate. For the as-cast specimen, accompanied by partial intragranular cracks, intergranular fracture along the grain boundaries in Sn-Ag eutectic structure or the interphase boundaries between Sn-rich dendrites and Sn-Ag eutectic phases occurred primarily in early tensile stage. However, the boundary behavior was limited by the large Ag 3 Sn particles presented along the Sn-rich dendrites boundaries after aging. Plastic flow was observed in large area, and cracks propagated in a transgranular manner across the Sn-dendrites and Sn-Ag eutectic structure

  10. Study on Tensile Fatigue Behavior of Thermal Butt Fusion in Safety Class III High-Density Polyethylene Buried Piping in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Lee, Young Ju; Oh, Young Jin

    2015-01-01

    High-density polyethylene (HDPE) piping, which has recently been applied to safety class III piping in nuclear power plants, can be butt-joined through the thermal fusion process, which heats two fused surfaces and then subject to axial pressure. The thermal fusion process generates bead shapes on the butt fusion. The stress concentrations caused by the bead shapes may reduce the fatigue lifetime. Thus, investigating the effect of the thermal butt fusion beads on fatigue behavior is necessary. This study examined the fatigue behavior of thermal butt fusion via a tensile fatigue test under stress-controlled conditions using finite element elastic stress analysis. Based on the results, the presence of thermal butt fusion beads was confirmed to reduce the fatigue lifetime in the low-cycle fatigue region while having a negligible effect in the medium- and high-cycle fatigue regions

  11. Study on Tensile Fatigue Behavior of Thermal Butt Fusion in Safety Class III High-Density Polyethylene Buried Piping in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Sung; Lee, Young Ju [Sunchon National University, Suncheon (Korea, Republic of); Oh, Young Jin [KEPCO E and C, Yongin (Korea, Republic of)

    2015-01-15

    High-density polyethylene (HDPE) piping, which has recently been applied to safety class III piping in nuclear power plants, can be butt-joined through the thermal fusion process, which heats two fused surfaces and then subject to axial pressure. The thermal fusion process generates bead shapes on the butt fusion. The stress concentrations caused by the bead shapes may reduce the fatigue lifetime. Thus, investigating the effect of the thermal butt fusion beads on fatigue behavior is necessary. This study examined the fatigue behavior of thermal butt fusion via a tensile fatigue test under stress-controlled conditions using finite element elastic stress analysis. Based on the results, the presence of thermal butt fusion beads was confirmed to reduce the fatigue lifetime in the low-cycle fatigue region while having a negligible effect in the medium- and high-cycle fatigue regions.

  12. Influence of heat treatment on microstructure and tensile behavior of a hot isostatically pressed nickel-based superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Chunlei, E-mail: c.qiu@bham.ac.uk [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Wu, Xinhua; Mei, Junfa [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Andrews, Paul; Voice, Wayne [Rolls-Royce Plc, Derby DE24 8BJ (United Kingdom)

    2013-11-25

    Highlights: •Post-HIP heat treatment led to refined microstructure and improved tensile properties. •Deformation occurred mainly by forming stacking faults in γ′ at RT and elevated temperature. •Net-shape HIPed RR1000 failed in a transgranular fracture mode. -- Abstract: A nickel-based superalloy powder RR1000 has been hot isostatically pressed (HIPed) and heat treated to produce different microstructures. Microstructures were investigated using a scanning electron microscope (SEM). Tensile testing was performed at room temperature and 700 °C and the deformed samples were examined using SEM and transmission electron microscope (TEM). It was found that in the as-HIPed condition the microstructure consisted of coarse and irregular-shaped primary and secondary γ′ together with a low volume fraction of fine γ′ (<50 nm in diameter). Solution treatment below the γ′ solvus followed by air cooling resulted in the formation of finer cuboidal secondary γ′ (350–750 nm) and medium-sized spherical tertiary γ′ (100–200 nm). This led to an improvement of both the 0.2% yield strength and ultimate tensile strength. Ageing of the solution-treated or of the as-HIPed samples at 760 °C resulted in the precipitation of a high population of fine γ′ (around 50 nm) which further increased the strength. Within the resolution limit of the current TEM analysis, deformation at room temperature seemed to occur mainly by dislocations cutting through secondary γ′ and very fine γ′, accompanied by the formation of stacking faults within these precipitates; most of the medium-sized tertiary γ′ precipitates in solution-treated and aged samples were not cut through but were surrounded by dislocations. Deformation at 700 °C happened by dislocations cutting through γ′ precipitates and γ matrix, leading to the formation of extended stacking faults across both γ and γ′. It is suggested that the optimum treatment of the current powder superalloy is to

  13. Influence of heat treatment on microstructure and tensile behavior of a hot isostatically pressed nickel-based superalloy

    International Nuclear Information System (INIS)

    Qiu, Chunlei; Wu, Xinhua; Mei, Junfa; Andrews, Paul; Voice, Wayne

    2013-01-01

    Highlights: •Post-HIP heat treatment led to refined microstructure and improved tensile properties. •Deformation occurred mainly by forming stacking faults in γ′ at RT and elevated temperature. •Net-shape HIPed RR1000 failed in a transgranular fracture mode. -- Abstract: A nickel-based superalloy powder RR1000 has been hot isostatically pressed (HIPed) and heat treated to produce different microstructures. Microstructures were investigated using a scanning electron microscope (SEM). Tensile testing was performed at room temperature and 700 °C and the deformed samples were examined using SEM and transmission electron microscope (TEM). It was found that in the as-HIPed condition the microstructure consisted of coarse and irregular-shaped primary and secondary γ′ together with a low volume fraction of fine γ′ (<50 nm in diameter). Solution treatment below the γ′ solvus followed by air cooling resulted in the formation of finer cuboidal secondary γ′ (350–750 nm) and medium-sized spherical tertiary γ′ (100–200 nm). This led to an improvement of both the 0.2% yield strength and ultimate tensile strength. Ageing of the solution-treated or of the as-HIPed samples at 760 °C resulted in the precipitation of a high population of fine γ′ (around 50 nm) which further increased the strength. Within the resolution limit of the current TEM analysis, deformation at room temperature seemed to occur mainly by dislocations cutting through secondary γ′ and very fine γ′, accompanied by the formation of stacking faults within these precipitates; most of the medium-sized tertiary γ′ precipitates in solution-treated and aged samples were not cut through but were surrounded by dislocations. Deformation at 700 °C happened by dislocations cutting through γ′ precipitates and γ matrix, leading to the formation of extended stacking faults across both γ and γ′. It is suggested that the optimum treatment of the current powder superalloy is to

  14. Tensile and shear fracture behavior of fiber reinforced plastics at 77K irradiated by various radiation sources

    International Nuclear Information System (INIS)

    Humer, K.; Weber, H.W.; Tschegg, E.K.; Gerstenberg, H.

    1993-08-01

    Influence of radiation damage (gamma, electron, neutron) on mechanical properties of fiber reinforced plastics (FRPs) has been investigated. Different types of FRPs (two or three dimensional E-, S- or T-glass fiber reinforcement, epoxy or bismaleimide resin) have been irradiated at room temperature with 2 MeV electrons and 6O Co γ-rays up to 1.8 x 1 0 8 Gy as well as with different reactor spectra up to a fast neutron fluence of 5 x lO 22 m -2 (E > 0.1 MeV). Tensile and intralaminar shear tests were carried out on the irradiated samples at 77 K. Some samples were irradiated at 5 K and tested at 77 K with and without an annealing cycle to room temperature. Results on the influence of these radiation conditions and of warm-up cycles on the mechanical properties of FRPs are compared and discussed

  15. Tensile and shear fracture behavior of fiber reinforced plastics at 77K irradiated by various radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Humer, K.; Weber, H.W. [Atominstitut der Oesterreichischen Hochschulen, Vienna (Austria); Tschegg, E.K. [Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik; Egusa, Shigenori [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Birtcher, R.C. [Argonne National Lab., IL (United States); Gerstenberg, H. [Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Physik

    1993-08-01

    Influence of radiation damage (gamma, electron, neutron) on mechanical properties of fiber reinforced plastics (FRPs) has been investigated. Different types of FRPs (two or three dimensional E-, S- or T-glass fiber reinforcement, epoxy or bismaleimide resin) have been irradiated at room temperature with 2 MeV electrons and {sup 6O}Co {gamma}-rays up to 1.8 {times} 1 0{sup 8} Gy as well as with different reactor spectra up to a fast neutron fluence of 5 {times} lO{sup 22} m{sup {minus}2} (E > 0.1 MeV). Tensile and intralaminar shear tests were carried out on the irradiated samples at 77 K. Some samples were irradiated at 5 K and tested at 77 K with and without an annealing cycle to room temperature. Results on the influence of these radiation conditions and of warm-up cycles on the mechanical properties of FRPs are compared and discussed.

  16. Development of a new ultrafine grained dual phase steel and examination of the effect of grain size on tensile deformation behavior

    Energy Technology Data Exchange (ETDEWEB)

    Saeidi, N., E-mail: navidsae@gmail.com; Ashrafizadeh, F.; Niroumand, B.

    2014-04-01

    Ultrafine grained dual phase (DP) steels are among the newest grades of DP steels that incorporate the uniform distribution of fine martensite particles (in the order of 1–2 μm) within a ferrite matrix. These new grades of steels have been developed in response to the world's demand for decreasing the fuel consumption in automobiles by increasing the strength to weight ratio. In the present research, a new kind of ultrafine grained DP (UFG-DP) steel with an average grain size of about 2 μm as well as a coarse grained DP (CG-DP) steel with an average grain size of about 5.4 μm was produced by consecutive intercritical annealing and cold rolling of low carbon AISI 8620 steel. The martensite volume fraction for both microstructures was the same and about 50 percent. Scanning electron microscopy (SEM) microstructural examination and room temperature tensile deformation analyses were performed on both UFG-DP and CG-DP steels and their deformation behavior in terms of strength, elongation and strain hardening was studied and compared. Room-temperature uniaxial tensile tests revealed that for a given martensite volume fraction, yield and tensile strengths were not very sensitive to martensite morphology. However, uniform and total elongation values were noticeably affected by refining martensite particles. The higher plasticity of fine martensite particles as well as the more uniform strain distribution within the UFG-DP microstructure resulted in higher strain hardenability and, finally, the higher ductility of the UFG-DP steel.

  17. High-Temperature Tensile and Tribological Behavior of Hybrid (ZrB2+Al3Zr)/AA5052 In Situ Composite

    Science.gov (United States)

    Gautam, G.; Kumar, N.; Mohan, A.; Gautam, R. K.; Mohan, S.

    2016-09-01

    During service life, components such as piston, cylinder blocks, brakes, and discs/drums, have to work under high-temperature conditions. In order to have appropriate material for such applications high-temperature studies are important. Hybrid (ZrB2+Al3Zr)/AA5052 in situ composite has been investigated from ambient to 523 K (250 °C) at an interval of 50 deg. (ZrB2+Al3Zr)/AA5052 in situ composite has been fabricated by the direct melt reaction of AA5052 alloy with zirconium and boron salts. Microstructure studies show refinement in the grain size of base alloy on in situ formation of reinforcement particles. Al3Zr particles are observed in rectangular and polyhedron shapes. It is observed from the tensile studies that ultimate tensile strength, yield strength, and percentage elongation decrease with increase in test temperature. Similar kind of behavior is also observed for flow curve properties. The tensile results have also been correlated with fractography. Wear and friction results indicate that the wear rate increases with increase in normal load, whereas coefficient of friction shows decreasing trend. With increasing test temperature, wear rate exhibits a typical phenomenon. After an initial increase, wear rate follows a decreasing trend up to 423 K (150 °C), and finally a rapid increase is observed, whereas coefficient of friction increases continuously with increase in test temperature. The mechanisms responsible for the variation of wear and friction with different temperatures have been discussed in detail with the help of worn surfaces studies under scanning electron microscope (SEM) & 3D-profilometer and debris analysis by XRD.

  18. Microstructure and mechanical properties of neutron irradiated OFHC-copper before and after post-irradiation annealing

    International Nuclear Information System (INIS)

    Singh, B.N.; Edwards, D.J.; Toft, P.

    2001-02-01

    Tensile specimens of OFHC-copper were irradiated with fission neutrons in the DR-3 reactor at Risoe National Laboratory at 100 deg. C to different displacement dose levels in the range of 0.01 to 0.3 dpa (NRT). Some of the specimens were tensile tested in the as-irradiated condition at 100 deg. C whereas other were given a post-irradiation annealing at 300 deg. C for 50 h and subsequently tested at 100 deg. C. Transmission electron microscopy was used to characterize the microstructure of specimens in the as-irradiation as well as irradiation and annealed conditions both before and after tensile deformation. The results show that while the interstitial loop microstructure coarsens with irradiation dose, no significant changes are observed in the population of stacking fault tetrahedra. The results also illustrates that the post-irradiation annealing leads to only a partial recovery and that the level of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates the problem of yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade induced source hardening (CISH) and the dispersed barrier hardening (DBH) models. Both technological and scientific implications of these results are considered. (au)

  19. Postirradiation changes in the pelvic wall

    International Nuclear Information System (INIS)

    Soevik, E.; Lien, H.H.; Tveit, K.M.

    1993-01-01

    MR images of 45 patients who had received radiation therapy for carcinoma of the anus or recurrent carcinoma of the rectum were reviewed with regard to postirradiation changes of the pelvic wall. High signal intensity in bone marrow on T1-weighted images due to fatty replacement was almost always observed. Presacral edema occurred in 7 of 36 patients who were examined 4 to 6 weeks after the end of irradiation and was more frequent at later studies. The pelvic wall muscles showed high signal intensity on T2-weighted images compatible with edema. This finding was most frequent on studies performed more than 6 weeks after the end of irradiation. The changes subsided more than a year after radiation therapy. To avoid an erroneous diagnosis of tumor infiltration into the pelvic wall, it is important to be familiar with the normal postirradiation changes of the presacral space and the muscles. (orig.)

  20. Postirradiation sarcoma in retinoblastoma. Induction or predisposition

    International Nuclear Information System (INIS)

    Schwarz, M.B.; Burgess, L.P.; Fee, W.E. Jr.; Donaldson, S.S.

    1988-01-01

    An alarmingly high rate of postirradiation sarcomas following treatment for retinoblastoma has been described in the literature. We present four new cases and report 57 others from the English literature. Osteogenic sarcoma was the predominant histologic type (58%), followed by fibrosarcoma (21%) and various other sarcomas (21%). The average latency period between irradiation and development of the second primary (sarcoma) was 12.4 years. Irrespective of irradiation, a genetic linkage between retinoblastoma and osteogenic sarcoma on the 13q14 chromosome is recognized. Through a pleiotropic effect of this same chromosome, a predisposition for other sarcomas may exist as well. Finally, a strong role for radiation induction is proposed for all of these postirradiation sarcomas. This is based on the increased number of sarcomas arising in the field of prior irradiation (sites uncharacteristic of spontaneously occurring primary sarcomas) and the prolonged latency periods.13 references

  1. Heat treatment effect on the microstructure, tensile properties and dry sliding wear behavior of A356-10%B4C cast composites

    International Nuclear Information System (INIS)

    Lashgari, H.R.; Zangeneh, Sh.; Shahmir, H.; Saghafi, M.; Emamy, M.

    2010-01-01

    In present paper, an attempt was made to examine the influence of T6 heat treatment (solution treatment at 540 o C for 5 h, quenching in hot water and artificial aging at 170 o C for 8 h) on the microstructure, tensile properties and dry sliding wear behavior of A356-10%B 4 C cast composites. The composite ingots were made by stir casting process. In this work, the matrix alloy and composite were characterized by optical microscope, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, tensile tests and conventional pin-on-disk experiment. The obtained results showed that in Al-B 4 C composite, T6 treatment was a dominant factor on the hardness improvement in comparison with hardness increasing due to the addition of B 4 C hard particles. In addition, T6 treatment can contribute to the strong bonding between B 4 C and matrix alloy and also it can change eutectic silicon morphology from acicular to near spherical. This case can lead to higher strength and wear properties of heat treated metal matrix composites in comparison with unheat treated state. Observation of worn surfaces indicated detachment of mechanically mixed layer which can primarily due to the delamination wear mechanism under higher applied load.

  2. Experimental and finite element study of the effect of temperature and moisture on the tangential tensile strength and fracture behavior in timber logs

    DEFF Research Database (Denmark)

    Larsen, Finn; Ormarsson, Sigurdur

    2014-01-01

    Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments and nume......Timber is normally dried by kiln drying, in the course of which moisture-induced stresses and fractures can occur. Cracks occur primarily in the radial direction due to tangential tensile strength (TSt) that exceeds the strength of the material. The present article reports on experiments...... and numerical simulations by finite element modeling (FEM) concerning the TSt and fracture behavior of Norway spruce under various climatic conditions. Thin log disc specimens were studied to simplify the description of the moisture flow in the samples. The specimens designed for TS were acclimatized...... to a moisture content (MC) of 18% before TSt tests at 20°C, 60°C, and 90°C were carried out. The maximum stress results of the disc simulations by FEM were compared with the experimental strength results at the same temperature levels. There is a rather good agreement between the results of modeling...

  3. Tensile stress-dependent fracture behavior and its influences on photovoltaic characteristics in flexible PbS/CdS thin-film solar cells.

    Science.gov (United States)

    Lee, Seung Min; Yeon, Deuk Ho; Mohanty, Bhaskar Chandra; Cho, Yong Soo

    2015-03-04

    Tensile stress-dependent fracture behavior of flexible PbS/CdS heterojunction thin-film solar cells on indium tin oxide-coated polyethylene terephthalate (PET) substrates is investigated in terms of the variations of fracture parameters with applied strains and their influences on photovoltaic properties. The PbS absorber layer that exhibits only mechanical cracks within the applied strain range from ∼0.67 to 1.33% is prepared by chemical bath deposition at different temperatures of 50, 70, and 90 °C. The PbS thin films prepared at 50 °C demonstrate better mechanical resistance against the applied bending strain with the highest crack initiating bending strain of ∼1.14% and the lowest saturated crack density of 0.036 μm(-1). Photovoltaic properties of the cells depend on the deposition temperature and the level of applied tensile stress. The values of short-circuit current density and fill factor are dramatically reduced above a certain level of applied strain, while open-circuit voltage is nearly maintained. The dependency of photovoltaic properties on the progress of fractures is understood as related to the reduced fracture energy and toughness, which is limitedly controllable by microstructural features of the absorber layer.

  4. Postirradiation examination of ORR demonstration elements

    International Nuclear Information System (INIS)

    Snelgrove, J.L.; Copeland, G.L.; Hofman, G.L.

    1991-01-01

    Postirradiation examinations of selected U 3 Si 2 fuel elements fabricated by B and W, CERCA, and NUKEM and irradiated during the whole core demonstration in the Oak Ridge Research Reactor are nearing completion. The results of all tests have shown the demonstration fuel elements, produced under production-line conditions, to have performed in the excellent manner expected from earlier tests of miniature fuel plates and full-sized elements. (orig.)

  5. Postirradiated and nonirradiated gliosarcoma: immunophenotypical profile

    International Nuclear Information System (INIS)

    Ang, L.C.; Perry, J.R.; Bilbao, J.M.; Ozane, W.; Nelson, N.

    1996-01-01

    Thirty-one gliosarcomas (25 nonirradiated and 6 postirradiated tumors) were selected based on the presence of two distinctive areas: a malignant gliomatous and a sarcomatous component. In all cases, the sarcomatous component appears like fibrosarcoma or malignant fibrous histiocytoma. Two tumors showed additional areas consisting of osteochondroid differentiation. All tumors were examined using antibodies against Ulex europaeus agglutinin I (UEA), glial fibrillary acidic protein (GFAP), vimentin (VM), epithelial membrane antigen (EMA), desmin, collagen IV, alpha-1-antitrypsin (α-1-AT) and smooth muscle actin (SMA). While the VM high-lighted the sarcomatous areas of all tumors there were only scattered spindle cells that were GFAP-positive in the same areas. The α-1-AT was diffusely reactive in the sarcomatous areas in 20 cases. Focal immunoreactivity was seen with SMA (20 tumors), UEA (8 tumors), EMA (5 tumors), collagen IV (5 tumors) and desmin (4 tumors) in the nonvascular sarcomatous cells. The range of immunophenotypical expression is likely to be a reflection of the capacity of a multipotential progenitor to undergo divergent differentiation. There is very little morphological difference between the postirradiated tumors except that a higher proportion of postirradiated tumors are immunoreactive to SMA and desmin. (author). 40 refs., 2 tabs., 8 figs

  6. Elevated temperature tensile and creep behavior of a SiC fiber-reinforced titanium metal matrix composite. Final Report, 22 Dec. 1994 M.S. Thesis, 7 May 1993

    Science.gov (United States)

    Thurston, Rita J.

    1995-01-01

    In this research program, the tensile properties and creep behavior in air of (0)(sub 4), (0/90)(sub s) and (90)(sub 4) SCS-9/Beta 21S composite layups with 0.24 volume fraction fiber were evaluated. Monotonic tensile tests at 23, 482, 650 and 815 C yielded the temperature dependence of the elastic modulus, proportional limit, ultimate tensile strength and total strain at failure. At 650 C, the UTS of the (0)(sub 4) and (0/90)(sub s) layups decreases by almost 50 percent from the room temperature values, indicating that operating temperatures should be less than 650 C to take advantage of the specific tensile properties of these composites.

  7. A Modified Constitutive Model for Tensile Flow Behaviors of BR1500HS Ultra-High-Strength Steel at Medium and Low Temperature Regions

    Science.gov (United States)

    Zhao, Jun; Quan, Guo-Zheng; Pan, Jia; Wang, Xuan; Wu, Dong-Sen; Xia, Yu-Feng

    2018-01-01

    Constitutive model of materials is one of the most requisite mathematical model in the finite element analysis, which describes the relationships of flow behaviors with strain, strain rate and temperature. In order to construct such constitutive relationships of ultra-high-strength BR1500HS steel at medium and low temperature regions, the true stress-strain data over a wide temperature range of 293-873 K and strain rate range of 0.01-10 s-1 were collected from a series of isothermal uniaxial tensile tests. The experimental results show that stress-strain relationships are highly non-linear and susceptible to three parameters involving temperature, strain and strain rate. By considering the impacts of strain rate and temperature on strain hardening, a modified constitutive model based on Johnson-Cook model was proposed to characterize flow behaviors in medium and low temperature ranges. The predictability of the improved model was also evaluated by the relative error (W(%)), correlation coefficient (R) and average absolute relative error (AARE). The R-value and AARE-value for modified constitutive model at medium and low temperature regions are 0.9915 & 1.56 % and 0.9570 & 5.39 %, respectively, which indicates that the modified constitutive model can precisely estimate the flow behaviors for BR1500HS steel in the medium and low temperature regions.

  8. Postirradiation sarcoma (malignant fibrous histiocytoma) following cervix cancer

    International Nuclear Information System (INIS)

    Pinkston, J.A.; Sekine, Ichiro.

    1980-12-01

    A case of postirradiation sarcoma is described. The tumor, a malignant fibrous histiocytoma, occurred in the radiation field 11 years following postoperative external beam radiation therapy (7,000 rad) for carcinoma of the cervix. Reports of postirradiation malignant fibrous histiocytoma are rare, and the occurrence of this neoplasm following treatment for cervix cancer has not previously been described. The literature concerning postirradiation bone and soft tissue sarcomas is briefly reviewed, with special attention to malignant fibrous histiocytomas. (author)

  9. Postirradiation examination results for the Irradiation Effects Scoping Test 2

    International Nuclear Information System (INIS)

    Mehner, A.S.

    1977-01-01

    The postirradiation examination results are reported for two rods from the second scoping test (IE-ST-2) of the Nuclear Regulatory Commission Irradiation Effects Program. The rods were irradiated in the in-pile test loop of the Power Burst Facility at the Idaho National Engineering Laboratory. Rod IE-005 was fabricated from fresh fuel and cladding previously irradiated in the Saxton Reactor. Rod IE-006, fabricated from fresh fuel and unirradiated cladding, was equipped with six developmental cladding surface thermocouples. The rods were preconditioned, power ramped, and then subjected to film boiling operation. The performance of the rods and the developmental thermocouples are evaluated from the post irradiation examination results. The effects of prior irradiation damage in cladding are discussed in relation to fuel rod behavior during a power ramp and subsequent film boiling operation

  10. Postirradiation examination of capsule GF-4

    International Nuclear Information System (INIS)

    Kovacs, W.J.; Sedlak, B.J.

    1980-10-01

    The GF-4 capsule test was irradiated in the SILOE reactor at Grenoble, France between April 8, 1975 and July 26, 1976. High-enriched uranium (HEU) UC 2 and weak acid resin (WAR) UC/sub x/O/sub y/ fissile and ThO 2 fertile particles were tested. Postirradiation examination of cured-in-place fuel rods showed no fuel rod/graphite element interaction. In addition, all rods exhibited adequate structural integrity. Irradiation-induced dimensional changes for rods containing all TRISO-coated fuel were consistent with model predictions; however, rods containing BISO-coated fuel exhibited greater volumetric contractions than predicted

  11. Tensile properties and strain-hardening behavior of double-sided arc welded and friction stir welded AZ31B magnesium alloy

    International Nuclear Information System (INIS)

    Chowdhury, S.M.; Chen, D.L.; Bhole, S.D.; Cao, X.; Powidajko, E.; Weckman, D.C.; Zhou, Y.

    2010-01-01

    Microstructures, tensile properties and work hardening behavior of double-sided arc welded (DSAWed) and friction stir welded (FSWed) AZ31B-H24 magnesium alloy sheet were studied at different strain rates. While the yield strength was higher, both the ultimate tensile strength and ductility were lower in the FSWed samples than in the DSAWed samples due to welding defects present at the bottom surface in the FSWed samples. Strain-hardening exponents were evaluated using the Hollomon relationship, the Ludwik equation and a modified equation. After welding, the strain-hardening exponents were nearly twice that of the base metal. The DSAWed samples exhibited stronger strain-hardening capacity due to the larger grain size coupled with the divorced eutectic structure containing β-Mg 17 Al 12 particles in the fusion zone, compared to the FSWed samples and base metal. Kocks-Mecking type plots were used to show strain-hardening stages. Stage III hardening occurred after yielding in both the base metal and the welded samples. At lower strains a higher strain-hardening rate was observed in the base metal, but it decreased rapidly with increasing net flow stress. At higher strains the strain-hardening rate of the welded samples became higher, because the recrystallized grains in the FSWed and the larger re-solidified grains coupled with β particles in the DSAWed provided more space to accommodate dislocation multiplication during plastic deformation. The strain-rate sensitivity evaluated via Lindholm's approach was observed to be higher in the base metal than in the welded samples.

  12. Effect of neutron irradiation and post-irradiation annealing on microstructure and mechanical properties of OFHC-copper

    International Nuclear Information System (INIS)

    Singh, B.N.; Edwards, D.J.; Toft, P.

    2001-01-01

    Specimens of oxygen-free high conductivity (OFHC) copper were irradiated in the DR-3 reactor at Risoe at 100 deg. C to doses in the range 0.01-0.3 dpa (NRT). Some of the specimens were tensile tested in the as-irradiated condition at 100 deg. C whereas others were given a post-irradiation annealing treatment at 300 deg. C for 50 h and subsequently tested at 100 deg. C. The microstructure of specimens was characterized in the as-irradiated as well as irradiated and annealed conditions both before and after tensile deformation. While the interstitial loop microstructure coarsens with irradiation dose, no significant changes were observed in the population of stacking fault tetrahedra (SFT). The post-irradiation annealing leads to only a partial recovery and the level of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates the yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade-induced source hardening (CISH) model

  13. Effect of neutron irradiation and post-irradiation annealing on microstructure and mechanical properties of OFHC-copper

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.N. E-mail: bachu.singh@risoe.dk; Edwards, D.J.; Toft, P

    2001-12-01

    Specimens of oxygen-free high conductivity (OFHC) copper were irradiated in the DR-3 reactor at Risoe at 100 deg. C to doses in the range 0.01-0.3 dpa (NRT). Some of the specimens were tensile tested in the as-irradiated condition at 100 deg. C whereas others were given a post-irradiation annealing treatment at 300 deg. C for 50 h and subsequently tested at 100 deg. C. The microstructure of specimens was characterized in the as-irradiated as well as irradiated and annealed conditions both before and after tensile deformation. While the interstitial loop microstructure coarsens with irradiation dose, no significant changes were observed in the population of stacking fault tetrahedra (SFT). The post-irradiation annealing leads to only a partial recovery and the level of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates the yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade-induced source hardening (CISH) model.

  14. Effect of neutron irradiation and post-irradiation annealing on microstructure and mechanical properties of OFHC-copper

    Science.gov (United States)

    Singh, B. N.; Edwards, D. J.; Toft, P.

    2001-12-01

    Specimens of oxygen-free high conductivity (OFHC) copper were irradiated in the DR-3 reactor at Risø at 100 °C to doses in the range 0.01-0.3 dpa (NRT). Some of the specimens were tensile tested in the as-irradiated condition at 100 °C whereas others were given a post-irradiation annealing treatment at 300 °C for 50 h and subsequently tested at 100 °C. The microstructure of specimens was characterized in the as-irradiated as well as irradiated and annealed conditions both before and after tensile deformation. While the interstitial loop microstructure coarsens with irradiation dose, no significant changes were observed in the population of stacking fault tetrahedra (SFT). The post-irradiation annealing leads to only a partial recovery and the level of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates the yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade-induced source hardening (CISH) model.

  15. Steel impurity element effects on postirradiation properties recovery by annealing

    International Nuclear Information System (INIS)

    Hawthorne, J.R.

    1987-01-01

    The influence of copper content and phosphorus content on notch ductility recovery by 399 0 C postirradiation heat treatment was explored for A 533-B and A 302-B pressure vessel steels. Charpy-V (C/sub V/) specimens for the investigation were obtained from ten plates produced from four (4-way split) laboratory melts. The plates were 15.2 mm thick but were heat treated to reproduce the microstructure of 150-mm and thicker A 302-B plates at the quarter-thickness location. The C/sub V/ specimens were irradiated in two assemblies at 288 0 C (550 0 F) to a fluence of --2.5 x 10/sup 19/ n/cm/sup 2/ in a light-water-cooled and moderated test reactor. Notch ductility properties in the asirradiated and 399 0 C, 168 h postirradiation-annealed conditions were determined. In addition, separate sets of specimens were thermally conditioned at 288 0 C and at 288 0 C followed by 399 0 C to benchmark the effects of temperature in the absence of irradiation. The results indicate that copper has a significant influence on the magnitude of residual embrittlement after annealing. In contrast, phosphorus contents in the range of 0.002 to 0.025% were found not to have an effect on residual embrittlement either in high or low copper steels. Essentially full recovery in 41-J transition temperature was observed for high phosphorus, low copper content steels. Effects of nickel alloying on recovery behavior were also investigated through data comparisons for A 302-B versus A 533-B plates

  16. Manifestations of damage from ionizing radiation in mammalian cells in the postirradiation generations

    International Nuclear Information System (INIS)

    Hopwood, L.E.; Tolmach, L.J.

    1979-01-01

    The lethally irradiated cell does not immediately cease metabolism. It may undergo one or many divisions before physiological death and disintegration ensue. Attention has been focused mainly on cell behavior during the generation in which the radiation is delivered, and cell behavior is in several respects very different in the irradiated generation from what it is in the succeeding generations. In particular, some of the responses in the irradiated generation are transient, and certain responses seem unrelated to lethal damage. The behavior of lethally irradiated cells during the postirradiation generations before they die is intrinsically of interest, and should provide information concerning the nature of the lethal damage they harbor. Accordingly, in reviewing the behavior of irradiated cells, the discussion is confined for the most part, though not entirely, to the postirradiations, even though distinction between the irradiated and the postirradiation generations is in several respects arbitrary. Effects at the cellular level are considered first; the final part of this section is devoted to a discussion of in vivo measurements of cellular effects, and includes responses that are properly classified as effects at the tissue level. The effects at the subcellular level are considered; the discussion is restricted to chromosomal effects. Biochemical effects are then considered; these are concerned entirely with macromolecular synthesis. In the final section possible interpretations of the experimental findings in terms of cell lethality are discussed but not loss of colony-forming ability (''clonogenicity'') directly

  17. Influence of Thermal Aging on Tensile and Low Cycle Fatigue Behavior of Type 316LN Austenitic Stainless Steel Weld Joint

    Science.gov (United States)

    Suresh Kumar, T.; Nagesha, A.; Ganesh Kumar, J.; Parameswaran, P.; Sandhya, R.

    2018-05-01

    Influence of short-term thermal aging on the low-cycle fatigue (LCF) behavior of 316LN austenitic stainless steel weld joint with 0.07 wt pct N has been investigated. Prior thermal exposure was found to improve the fatigue life compared with the as-welded condition. Besides, the treatment also imparted a softening effect on the weld metal, leading to an increase in the ductility of the weld joint which had a bearing on the cyclic stress response. The degree of cyclic hardening was seen to increase after aging. Automated ball-indentation (ABI) technique was employed toward understanding the mechanical properties of individual zones across the weld joint. It was observed that the base metal takes most of the applied cyclic strain during LCF deformation in the as-welded condition. In the aged condition, however, the weld also participates in the cyclic deformation. The beneficial effect of thermal aging on cyclic life is attributed to a reduction in the severity of the metallurgical notch leading to a restoration of ductility of the weld region. The transformation of δ-ferrite to σ-phase during the aging treatment was found to influence the location of crack initiation. Fatigue cracks were found to initiate in the base metal region of the joint in most of the testing conditions. However, embrittlement in the weld metal caused a shift in the point of crack initiation with increasing strain amplitude under LCF.

  18. Predictions of creep behavior of some stainless steels on the basis of short-term tensile properties

    International Nuclear Information System (INIS)

    Bui-Quoc, T.; Biron, A.

    1979-01-01

    A concept of cumulative damage has recently been developed for evaluating the amount of damage incurred by the material under the creep process. The damage accumulation is stress-dependent and is a non-linear function of time. This new approach allows one to establish the creep curve in the sigma-T diagram (sigma:applied stress, T:time at rupture) as well as to evaluate the remaining time to rupture when the material is subjected to several specified conditions of creep loading. The method takes into account the order effect of creep loading which has been observed experimentally and reported recently in the literature. Only the procedure related to the determination of the creep curve is discussed in the present paper. The isothermal creep behavior is represented by a single equation in which two material constants must be known in order to describe the complete creep curve. A good fit with experimental results for some materials is observed when these constants are evaluated by means of two reference data points chosen in the sigma/T diagram. (orig.)

  19. Cytogenetics of Post-Irradiation Mouse Leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Wald, N.; Pan, S.; Upton, A.; Brown, R. [Graduate School of Public Health, University of Pittsburgh, PA (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1969-11-15

    The interrelationship between radiation, cytogenetic abnormalities, and viruses in leukaemogenesis has been studied in the RF/Un mouse which develops a high incidence of granulocytic leukaemia on radiation exposure. A virus-like agent has been demonstrated in such leukaemic animals and the disease has been transmitted by passage of apparently acellular materials from irradiated primary animals to normal recipients. Pilot cytogenetic studies revealed consistent abnormal chromosome markers and modal shifts in both irradiated leukaemic animals and in non-irradiated animals developing leukaemia after passage injection. To define better the relationship between consistent bone-marrow chromosome aberrations and postirradiation primary and passaged leukaemia, 100 RF/Un mice were studied which were irradiated with 300 R of 250-kVp X-rays at 100 weeks of age and subsequently developed leukaemia. Eighty-seven had granulocytic leukaemia and in 72 of these, bone-marrow cytogenetic abnormalities were found. The distribution of-numerical and structural chromosome aberrations in 3225 cells studied are reviewed in derail. The correlation of specific aberrations to clinical and histopathologic findings has been attempted: Sequential passages of apparently cell-free material from the post-irradiation leukaemic mice into unirradiated RE/Un recipients and subsequent passages from leukaemic recipients were performed to observe the evolution of any initial chromosome markers and shifts in modal chromosome number in the passage generations. Two-hundred-thirty-six mice were inoculated with the material obtained either from primary post-irradiation leukaemic mice or from serially-passaged leukaemia cases. In the most extensive passaged line, 22 transfer generations containing 129 leukaemic mice were examined by clinical, histopathologic, -haematologic and cytogenetic procedures. Evolution of abnormal chromosome modes from 41 in the early passages to 39 chromosomes consistently after the 4

  20. Postirradiation fracture toughness of Inconel X-750

    International Nuclear Information System (INIS)

    Mills, W.J.

    1983-01-01

    The effect of fast-neutron irradiation on the fracture toughness response of Inconel X-750 was characterized at 427 deg C using the J-R curve technique. Irradiation exposures ranging from 3 to 16 displacements per atom resulted in a reduction in Jsub(Ic) from 130 to 76 kJ/m 2 and a reduction in tearing modulus from 32 to 2.6. Postirradiation fractographic examination revealed that an intergranular fracture mechanism was dominant, in contrast to the extensive transgranular cracking mode found on unirradiated fracture surfaces. The enhanced intergranular failure observed after irradiation was caused by extensive heterogeneous slip in a matrix that was greatly strengthened by an irradiation-induced dislocation substructure. Specifically, intense planar slip bands impinged on the grain boundaries and generated large stress concentrations. Since the stress concentrations could not be relaxed by the hardened matrix, the grain boundaries 'unzipped' readily, resulting in the low toughness and tearing resistance. (author)

  1. N Reactor pressure tube 2566 postirradiation examination

    International Nuclear Information System (INIS)

    Scott, K.V.

    1978-01-01

    Pressure tube 2566 was removed from N Reactor in July, 1977 to initiate the postirradiation examination program required by the Technical Specifications. Destructive examination of the pressure tube, after a maximum accumulated fluence of 4.6 x 10 21 n/cm 2 (E > 1 MeV), was conducted at the Hanford Engineering Development Laboratory to determine the effects of reactor service on the mechanical properties and hydrogen absorption and corrosion characteristics of the pressure tube. Tube 2566 is the sixth tube removed for destructive examination since the initial reactor startup. Evaluation of test results reveal that no significant detrimental changes have occurred in the parameters studied, since the last tube was removed in 1974

  2. Postirradiation flap infection about the oral cavity

    International Nuclear Information System (INIS)

    Cabbabe, E.B.; Herbold, D.R.; Sunwoo, Y.C.; Baroudi, I.F.

    1983-01-01

    Postirradiation alteration of oral flora is well documented in the literature. Infection as a complication leading to partial or complete loss of a flap used to reconstruct a defect in the oral cavity is a worrisome outcome. We describe how a flap that was judged clinically to be viable became overwhelmingly infected with the Klebsiella oxytoca, an oral cavity pathogen encountered in this patient following irradiation. Local and systemic changes led to detachment of the flap. This complication may be explained, in view of the absence of venous congestion or arterial ischemia both clinically and pathologically, by the proven contamination of the flap by the Klebsiella pathogen. Local factors resulted in lower resistance and subsequent overwhelming infection. Discussion of the case, review of pertinent literature, and proposed solutions are presented

  3. Mathematical Model for Post-Irradiation Haemopoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Okunewick, J. P.; Kretchmar, A. L. [Rand Corporation, Santa Monica, CA (United States); Medical Division, Oak Ridge Associated Universities, Oak Ridge, TN (United States)

    1968-08-15

    A model for haemopoiesis has been constructed based on the following hypothesis: (a) Haemopoietic stem cells have the capability of either reproducing as stem cells or differentiating into specialized blood cells of at least two different types; (b) The size of the stem-cell compartment is in part regulated by the rate of increase due to stem-cell reproduction and in part by the rate of loss of stem cells through differentiation; (c) In addition, the size of the stem-cell compartment is in part regulated by a competitive cell-to-cell interaction between the stem-cells themselves and between the differentiating cells and the stem-cells, such that the presence of an exceptionally large number of either cell type would have a repressive effect on the rate of increase of the stem-cell population. This model has been applied to the post-irradiation erythropoietic behaviour of the rat. In the computer studies with the model, an X-ray dose sufficient to inhibit reproduction in 50% of the erythroid stem cells was assumed. It was also assumed that reproduction and differentiation are genetically separately controlled processes and that, therefore, some part of the reproductively injured cells were still capable of differentiation. Under these conditions the model predicted an abortive rise in reticulocyte number, peaking at about 6 days. True recovery was predicted to occur at about 16 days. Both the abortive rise and the true recovery were also present in those segments of the model representing earlier erythroid cells, occurring at progressively earlier times in progressively more primitive cells. Comparison of the model's predictions with experimentally obtained data for post-irradiation erythroid recovery showed a good agreement both with respect to the time of the abortive peak and the time of true recovery. (author)

  4. Mathematical Model for Post-Irradiation Haemopoiesis

    International Nuclear Information System (INIS)

    Okunewick, J.P.; Kretchmar, A.L.

    1968-01-01

    A model for haemopoiesis has been constructed based on the following hypothesis: (a) Haemopoietic stem cells have the capability of either reproducing as stem cells or differentiating into specialized blood cells of at least two different types; (b) The size of the stem-cell compartment is in part regulated by the rate of increase due to stem-cell reproduction and in part by the rate of loss of stem cells through differentiation; (c) In addition, the size of the stem-cell compartment is in part regulated by a competitive cell-to-cell interaction between the stem-cells themselves and between the differentiating cells and the stem-cells, such that the presence of an exceptionally large number of either cell type would have a repressive effect on the rate of increase of the stem-cell population. This model has been applied to the post-irradiation erythropoietic behaviour of the rat. In the computer studies with the model, an X-ray dose sufficient to inhibit reproduction in 50% of the erythroid stem cells was assumed. It was also assumed that reproduction and differentiation are genetically separately controlled processes and that, therefore, some part of the reproductively injured cells were still capable of differentiation. Under these conditions the model predicted an abortive rise in reticulocyte number, peaking at about 6 days. True recovery was predicted to occur at about 16 days. Both the abortive rise and the true recovery were also present in those segments of the model representing earlier erythroid cells, occurring at progressively earlier times in progressively more primitive cells. Comparison of the model's predictions with experimentally obtained data for post-irradiation erythroid recovery showed a good agreement both with respect to the time of the abortive peak and the time of true recovery. (author)

  5. Effect of the Volume Fraction of Jute Fiber on the Interlaminar Shear Stress and Tensile Behavior Characteristics of Hybrid Glass/Jute Fiber Reinforced Polymer Composite Bar for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Chan-Gi Park

    2016-01-01

    Full Text Available Hybrid glass/jute fiber reinforced polymer (HGJFRP composite bars were manufactured for concrete structures, and their interlaminar shear stress and tensile performance were evaluated. HGJFRP composite bars were manufactured using a combination of pultrusion and braiding processes. Jute fiber was surface-treated with a silane coupling agent. The mixing ratio of the fiber to the vinyl ester used in the HGJFRP composite bars was 7 : 3. Jute fiber was used to replace glass fiber in proportions of 0, 30, 50, 70, and 100%. The interlaminar shear stress decreased as the proportion of jute fiber increased. Fractures appeared due to delamination between the surface-treated component and the main part of the HGJFRP composite bar. Tensile load-strain curves with 50% jute fiber exhibited linear behavior. With a jute fiber volume fraction of 70%, some plastic deformation occurred. A jute fiber mixing ratio of 100% resulted in a display of linear elastic brittle behavior from the fiber; however, when the surface of the fiber was coated with poly(vinyl acetate, following failure, the jute fiber exhibited partial load resistance. The tensile strength decreased as the jute fiber content increased; however, the tensile strength did not vary linearly with jute fiber content.

  6. Comparison of MOS capacitor and transistor postirradiation response

    International Nuclear Information System (INIS)

    McWhorter, P.J.; Fleetwood, D.M.; Pastorek, R.A.; Zimmerman, G.T.

    1989-01-01

    The postirradiation response of MOS capacitors and transistors fabricated on the same chip has been examined as a function of dose and anneal bias. A variety of analysis techniques are used to evaluate the postirradiation response of these structures, including low and high frequency capacitance-voltage techniques, subthreshold current-voltage techniques, and charge pumping. Though there are changes in the postirradiation energy spectrum of ΔD it , no clear evidence of defect transformation is observed on transistors or capacitors under any conditions examined. Postirradiation response at 80 degrees C is found to be similar in the two structures for low levels of damage (100 krad). For both structures, interface-trap densities continue to grow following irradiation under these conditions. In contrast, the postirradiation response of capacitors and transistors can differ qualitatively at higher levels of damage (1 Mrad), with interface-traps increasing postirradiation at 80 degrees C for transistors and annealing for capacitors. These results indicate that capacitor structures may not be suitable for hardness assurance studies that involve elevated temperature irradiations or postirradiation anneals

  7. Interpretation of quasi-static and dynamic tensile behavior by digital image correlation technique in TWinning Induced Plasticity (TWIP) and low-carbon steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Minju; Park, Jaeyeong; Sohn, Seok Su; Kim, Hyoung Seop [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kim, Nack J. [Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, Sunghak, E-mail: shlee@postech.ac.kr [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2017-05-02

    In this study, dynamic tensile tests were conducted on TWinning Induced Plasticity (TWIP) and low-carbon (LC) steel sheets at a strain rate of 1500–2000/s by using a split Hopkinson tensile bar, and deformation mechanisms related with improvement of dynamic tensile properties were investigated by a digital image correlation (DIC) technique. The dynamic tensile strength was higher than the quasi-static tensile strength in both TWIP and LC sheets, while the dynamic elongation was same to the quasi-static elongation in the TWIP sheet and was much lower than the quasi-static elongation in the LC sheet. According to the DIC results of the dynamically tensioned TWIP sheet, the homogeneous deformation occurred before the necking at the strain of 47.4%. This indicated that the dynamic deformation processes were almost similar to the quasi-static ones as the TWIP sheet was homogeneously deformed in the initial and intermediate deformation stages. This could be explained by deformation mechanisms including twinning, in consideration of favorable effect of increased twinning on tensile properties under the dynamic loading. On the other hand, the dynamically tensioned LC sheet was rapidly deformed and fractured as the necking was intensified in a narrow strain-concentrated region. The present DIC technique is an outstanding method for detailed dynamic deformation analyses, and provides an important idea for practical safety analyses of automotive steel sheets.

  8. Influence of deuterium content on tensile behavior of Zr-2.5Nb pressure tube material in the temperature range of ambient to 300 degC

    International Nuclear Information System (INIS)

    Bind, A.K.; Singh, R.N.; Chakravartty, J.K.; Dhandharia, Priyesh; Ghosh, Agnish; More, Nitin S.; Chhatre, A.G.; Vijayakumar, S.

    2011-08-01

    Tensile properties of autoclaved zirconium-2.5 wt. % niobium pressure tube material were evaluated by uniaxial tension tests at temperatures between 25 and 300 degC and under strain-rates of 1.075 x 10 -4 /s. Six number of Zr-2.5Nb alloy pressure tube spools of length 130 mm were obtained from pressure tube number 19-2557-2. Five spools were polished with abrasive paper to remove the oxide layer. These spools were gaseously charged with controlled amount of deuterium. The target deuterium concentrations were 25, 50, 75, 100 and 200 wppm of hydrogen equivalent. Ten samples were machined by EDM wire cutting from every spool. The tensile specimen axis was oriented along longitudinal direction of the tube. Metallographic examination of the deuterium charged samples suggested that the deuterides were predominantly circumferential deuterides. Analysis of tensile results showed that both yield and ultimate tensile strengths of this alloy decreased monotonically with increasing test temperatures. The tensile ductility decreased marginally with increase in test temperature from ambient to 300 degC. It was also observed that both strength and ductility appear to be unaffected by deuterium content at all temperatures, thereby suggesting that at least up to 200 wppm (Heq.) of deuterium tensile properties are not influenced by deuterium. (author)

  9. Available post-irradiation examination techniques at Romanian institute for nuclear research

    International Nuclear Information System (INIS)

    Parvan, Marcel; Sorescu, Antonius; Mincu, Marin; Uta, Octavian; Dobrin, Relu

    2005-01-01

    The Romanian Institute for Nuclear Research (INR) has a set of nuclear facilities consisting of TRIGA 14 MW(th) materials testing reactor and LEPI (Romanian acronym for post-irradiation examination laboratory) which enable to investigate the behaviour of the nuclear fuel and materials under various irradiation conditions. The available techniques of post-irradiation examination (PIE) and purposes of PIE for CANDU reactor fuel are as follows. 1) Visual inspection and photography by periscope: To examine the surface condition such as deposits, corrosion etc. 2) Eddy current testing: To verify the cladding integrity. 3) Profilometry and length measurement performed both before and after irradiation: To measure the parameters which highlight the dimensional changes i.e. diameter, length, diametral and axial sheath deformation, circumferential sheath ridging height, bow and ovality. 4) Gamma scanning and Tomography: To determine the burnup, axial and radial fission products activity distribution and to check for flux peaking and loading homogeneity. 5) Puncture test: To measure the pressure, volume and composition of fission gas and the inner free volume. 6) Optical microscopy: To highlight the structural changes and hydriding, to examine the condition of the fuel-sheath interface and to measure the oxide thickness and Vickers microhardness. 7) Mass spectrometry: To measure the burnup. 8) Tensile testing: To check the mechanical properties. So far, non-destructive and destructive post-irradiation examinations have been performed on a significant number of CANDU fuel rods (about 100) manufactured by INR and irradiated to different power histories in the INR 14 MW(th) TRIGA reactor. These examinations have been performed as part of the Romanian research programme for the manufacturing, development and safety of the CANDU fuel. The paper describes the PIE techniques and some results. (Author)

  10. Postirradiation examination data report for gap conductance test series. Test GC 2-1

    International Nuclear Information System (INIS)

    Murdock, B.A.

    1978-02-01

    The results of the postirradiation examination of four boiling water reactor type, zircaloy-clad, UO 2 -fueled rods tested in the Power Burst Facility are discussed. These rods were employed in Gap Conductance Test GC 2-1 which was performed to obtain experimental data from which test fuel rod gap conductance values could be determined by both the steady state ∫kdT and the power oscillation methods. The postirradiation examination results provided in the document will aid in interpreting the experimental data obtained during Test GC 2-1 and in evaluating the effect of fuel behavior on the fuel rod thermal response and interpreted gap conductances. Fuel rod fill gas composition and pressure are discussed. Measurements of fuel pellet-cladding gap and fuel crack areas are presented. The fuel structure is analyzed. Test rod instrumentation and power profiles are examined to better evaluate the test conditions

  11. Polyamines and post-irradiation cell proliferation

    International Nuclear Information System (INIS)

    Rosiek, O.; Wronowski, T.; Lerozak, K.; Kopec, M.

    1978-01-01

    The results of three sets of experiments will be presented. Firstly polyamines and DNA content was determined in bone marrow, mesenteric lymph nodes, spleen, liver and kidney of rabbits at the 1, 5, 10 and 20th day after exposure to 600 R of X-irradiation. Polyamine concentration in bone marrow, spleen and lymph nodes was found to be markedly increased during the period of postirradiation recovery. Secondly, effect of 10 -5 M methyl glyoxalbis, guanylhydrazone (MGBG), an inhibitor of spermidine and spermine synthesis, on multiplication of X-irradiated cultures of murine lymphoblaste L5178Y-S was assessed. MGBG-induced inhibition of cell proliferation could be prevented by concurrent administration of 10 -4 M spermidine. Thirdly the influence of putrescine on bone marrow cellularity and 3 H-thymidine incorporation into bone marrow cells was investigated in X-irradiated mice. The results obtained indicate close relation of polyamines to cell proliferation processes after irradiation. (orig./AJ) [de

  12. Postirradiation examinations of the BG-9 element

    International Nuclear Information System (INIS)

    Strain, R.V.; Renfro, C.W.; Neimark, L.A.

    1976-10-01

    Postirradiation examinations were performed on the GB-9 element irradiated in the Oak Ridge Reactor. This vented fuel element was irradiated to a peak burnup of 54,000 MWd/MT at a peak power rating of 14.8 kW/ft and a maximum outside surface temperature of 685 +- 15 0 C. The maximum diametral increase of the element was 0.2% ΔD/D. Volatile fission products migrated to the ends of the fuel column but had not been transported beyond the blanket region of the element. Fission-product attack of the cladding was found to a depth of 4.4 mils adjacent to the mixed-oxide fuel. The maximum fission-product attack (approximately 6.2 mils) was found adjacent to slightly hyperstoichiometric UO 2 pellets at the upper end of the fuel column. The more severe attack in this region has been attributed to the higher oxygen potential adjacent to the hyperstoichiometric UO 2 fuel. A stress-rupture test was performed on a section of the element. The cladding ruptured after 30 min at 700 0 C and approximately 21,500-psi loop stress, resulting in a diametral strain of 1.6%

  13. Operation of post-irradiation examination facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E. G.; Jeon, Y. B.; Ku, D. S.

    1996-12-01

    In 1996, the post-irradiation examination(PIE) of nuclear fuels was performed as follows. It has been searched for the caution of defection of defected fuel rods of Youngkwang-4 reactor through NDT and metallographic examination that had been required by KEPCO. And in-pool inspection of Kori-1 spent fuel assembly(FO2) was carried out. HVAC system and pool water treatment system have been operated to maintain the facility safely, and electric power supply system was checked and maintained for the normal and steady supply electric power to the facility. Image processing software was developed for measurement of defection of spent fuel rods. Besides, a radiation shielding glove box was fabricated and a hot cell compressor for volume reduction of radioactive materials was fabricated and installed in hot cell. Safeguards of nuclear materials were implemented in strict accordance with the relevant Korean rules and regulations as well as the international non-proliferation regime. Also the IAEA inspection was carried out on the quarterly basis. (author). 31 tabs., 71 figs., 4 refs.

  14. N Reactor pressure tube 1350 postirradiation examination

    International Nuclear Information System (INIS)

    Cook, D.J.

    1977-01-01

    The N Reactor pressure tubes were fabricated from Zircaloy-2 primarily due to the excellent corrosion resistance, low neutron absorption, and high strength properties of this alloy. Irradiation damage mechanisms increase the strength and decrease the ductility of the Zircaloy-2. Irradiation data available at the time the tubes were installed indicated that fast neutron irradiation damage mechanisms would not decrease the ductility to unacceptable levels over the estimated plant life of 25 to 30 years. However, because the tubes are a primary coolant system component and only limited data are available on irradiation effects at high fluences, a Postirradiation Examination (PIE) program was developed to assure that service factors do not compromise pressure tube integrity essential to reactor safety. The PIE program requires that a pressure tube be periodically removed from the reactor for destructive testing. The N Reactor Technical Specifications specify that the frequency of pressure tube removal and examination be based upon the previous PIE test results. Four pressure tubes were examined before tube 1350, and the test results were summarized in individual reports. PIE results on tube 1350 were summarized along with the test results on the previous four tubes in a previous report. The purpose of this report is to present in detail the results on PIE of pressure tube 1350, and, in particular, document the technique by which the fracture toughness of the pressure tube was determined

  15. Modification of bacterial cell survival by postirradiation hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Vexler, F B; Eidus, L Kh

    1986-01-27

    It is shown that postirradiation hypoxia affects the survival of E.coli. Hypoxic conditions immediately after a single-dose irradiation diminish cell survival in nutrient medium. Increasing time intervals between irradiation and hypoxia decrease the efficiency of the latter, while 1 h after irradiation hypoxia does not modify the survival of irradiated cells. These findings reveal that the mechanisms of action of postirradiation hypoxia on eu- and prokaryotic cells are similar.

  16. SOLID BURNT BRICKS’ TENSILE STRENGTH

    Directory of Open Access Journals (Sweden)

    Aneta Maroušková

    2017-11-01

    Full Text Available This paper deals with experimental testing of solid burnt bricks and mortar in pure (axial tension. The obtained working diagrams will be further use for a detailed numerical analysis of whole brick masonry column under concentric compressive load. Failure mechanism of compressed brick masonry column is characterized by the appearance and development of vertical tensile cracks in masonry units (bricks passing in the direction of principal stresses and is accompanied by progressive growth of horizontal deformations. These cracks are caused by contraction and interaction between two materials with different mechanical characteristics (brick and mortar. The aim of this paper is more precisely describe the response of quasi-brittle materials to uniaxial loading in tension (for now only the results from three point bending test are available. For these reasons, bricks and mortar tensile behavior is experimentally tested and the obtained results are discussed.

  17. Tensile properties of unirradiated path A PCA

    International Nuclear Information System (INIS)

    Braski, D.N.; Maziasz, P.J.

    1983-01-01

    The tensile properties of PCA in the Al (solution annealed), A3 (25%-cold worked), and B2 (aged, cold worked, and reaged) conditions were determined from room temperature to 600 0 C. The tensile behavior of PCA-A1 and -A3 was generally similar to that of titanium-modified type 316 stainless steel with similar microstructures. The PCA-B2 was weaker than PCA-A3, especially above 500 0 C, but demonstrated slightly better ducility

  18. Post-irradiation effects in CMOS integrated circuits

    International Nuclear Information System (INIS)

    Zietlow, T.C.; Barnes, C.E.; Morse, T.C.; Grusynski, J.S.; Nakamura, K.; Amram, A.; Wilson, K.T.

    1988-01-01

    The post-irradiation response of CMOS integrated circuits from three vendors has been measured as a function of temperature and irradiation bias. The author's have found that a worst-case anneal temperature for rebound testing is highly process dependent. At an anneal temperature of 80 0 C, the timing parameters of a 16K SRAM from vendor A quickly saturate at maximum values, and display no further changes at this temperature. At higher temperature, evidence for the anneal of interface state charge is observed. Dynamic bias during irradiation results in the same saturation value for the timing parameters, but the anneal time required to reach this value is longer. CMOS/SOS integrated circuits (vendor B) were also examined, and showed similar behavior, except that the saturation value for the timing parameters was stable up to 105 0 C. After irradiation to 10 Mrad(Si), a 16K SRAM (vendor C) was annealed at 80 0 C. In contrast to the results from the vendor A SRAM, the access time decreased toward prerad values during the anneal. Another part irradiated in the same manner but annealed at room temperature showed a slight increase during the anneal

  19. Postirradiation examination of BEATRIX-II, Phase 1

    International Nuclear Information System (INIS)

    Slagle, O.D.; Hobbs, F.D.; Baldwin, D.L.; Hollenberg, G.W.; Takahashi, T.; Noda, K.; Verrall, R.A.

    1993-09-01

    BEATRIX-II is an in situ tritium recovery experiment that was designed to characterize the behavior of lithium ceramics irradiated to high burnup in a fast neutron flux. Postirradiation examination was carried out on the Phase 1 vented canisters: one containing a Li 2 O ring capable of temperature changes and the other a Li 2 O solid specimen with a center temperature of 1,000 degrees C. The tritium inventory of the ring specimen at 650 degrees C was determined to be in the range from 0.2--0.6 wppm while for the solid specimen the inventory varied from 1.4 wppm at the surface to 0.06 wppm at the inner surface. Downstream transport of the Li 2 O by the sweep gas was determined to be insignificant from analyses of acid rinses of selected canister surfaces. Densification and restructuring of the solid specimen during irradiation resulted in the development of a central annulus. Ceramography was used to characterize the columnar grain structure and the mechanisms involved in its evolution

  20. Operation of post-irradiation examination facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ka; Park, Kwang Joon; Jeon, Yong Bum [and others; Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    In 1995, the post-irradiation examination (PIE) of nuclear fuels was performed as follows. The relation between burnup and top nozzle spring force of fuel assembly was obtained by measuring the holddown spring force on the Kori-1 reactor fuel assemblies. The resonance ultrasonic test for inspection of defect and moisture in fuel rod was carried out on fuel rods of C15 and J14 assemblies, and the change of fuel rod condition by storing in pool has been analyzed on the intentionally defected fuel rods (ID-C and ID-L) as well as intact fuel rod (1-2) by NDT in ht cell. The oxide layer thickness on cladding surface of J44-L12 fuel rod was measured by NDT method and metallography to reveal the oxidation as a function of temperature in the fuel rod, and the burnup of J44 fuel assembly was measured by chemical analysis. HVAC system and pool water treatment system of the PIE facility were continuously operated for air filtration and water purification. The monitoring of radiation and pool water in PIE facility has been carried out to maintain the facility safety, and electric power supply system was checked and maintained to supply the electric power to the facility normally. The developed measurement techniques of oxide layer thickness on fuel rod cladding and holddown spring force of top nozzle in fuel assembly were applied to examine the nuclear fuels. Besides, a radiation shielding glove box was designed and a hot cell compressor for volume reduction of radioactive materials was fabricated. 19 tabs., 38 figs., 7 refs. (Author) .new.

  1. Capsule HRB-15B postirradiation examination report

    International Nuclear Information System (INIS)

    Ketterer, J.W.; Bullock, R.E.

    1981-06-01

    Capsule HRB-15B design tested 184 thin graphite trays containing unbonded fuel particles to peak exposures of 6.6 x 10 25 n/m 2 (E > 29 fJ)/sub HTGR/ fast fluence, approx. 27% fissions per initial metal atom (FIMA) fissile burnup, and 6% FIMA fertile burnup at nominal time-averaged temperatures of 815 to 915 0 C. The capsule tested a variety of low-enriched uranium (approx. 19.5% U-235) fissile particle types, including UC 2 , UC/sub x/O/sub y/, UO 2 , zirconium-buffered UO 2 (referred to in this report as UO 2 /sup *), and 1:1(Th,U)O 2 with both TRISO and silicon-BISO coatings. All fertile particles were ThO 2 with BISO, silicon-BISO, or TRISO coatings. The findings indicated that all TRISO particles retained virtually all of their fission product inventories, except small quantities of silver, at these irradiation temperatures, while some of the silicon-BISO particles released significant amounts of both silver and cesium. No kernel migration, pressure vessel, or outer pyrolytic carbon (OPyC) failures were observed in the fuel particles, which had total diameters of 2 /sup */ particles exhibited no detrimental irradiation effects, but they contained pure carbon precipitates in the kernels after irradiation which were not observed in the undoped UO 2 particles. Postirradiation examination revealed no differences in the irradiation performance of three UC/sub x/O/sub y/ kernel types with varying oxygen/uranium ratios

  2. Experimental studies on the dynamic tensile behavior of Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si alloy with Widmanstatten microstructure at elevated temperatures

    International Nuclear Information System (INIS)

    Gong Xuhui; Wang Yu; Xia Yuanming; Ge Peng; Zhao Yongqing

    2009-01-01

    The tensile behavior of a newly developed Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si alloy, referred as TC21, is investigated at temperatures ranging from 298 to 1023 K and under constant strain rate loadings ranging from 0.001 to 1270 s -1 . The results show that temperature and strain rate have significant effects on the tensile behavior of the material. At low strain rates of 0.001 and 0.05 s -1 , a discontinuity is found in the yield stress-temperature curve. And the discontinuity temperature increases with increasing strain rate. The analysis of temperature and strain rate dependence of unstable strain indicates a high-velocity-ductility phenomenon at elevated temperatures. Scanning electron microscope (SEM) analysis shows that the material is broken in a mixture manner of ductile fracture and intergranular fracture under low strain rates at room temperature, while the fracture manner changes to totally ductile fracture under other testing conditions. The width and depth of ductile dimples increase with increasing temperature. No adiabatic shear band is found in the tensile deformation of the material.

  3. Effect of holes on the room temperature tensile behaviors of thin wall specimens with (210) side surface of Ni-base single crystal superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z.J.; Liu, T.; Pu, S. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Xu, H. [Materials Fatigue and Fracture Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Wang, L., E-mail: wangli@imr.ac.cn [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Lou, L.H. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China)

    2015-10-25

    Tensile properties of Ni-base single crystal superalloy plate specimens with and without a hole at room temperature were studied in the present paper. During the testing process, an ARAMIS system based on the digital image correlation technique and in-situ scanning electron microscopy were employed to in-situ observe the strain distribution and slip traces development on the sample surfaces. It was demonstrated that the yield stress was decreased with the appearance of a hole due to the stress concentration. The results were analyzed based on the stress and strain states of specimens and the slip traces development observed on specimen surfaces. - Graphical abstract: The strain distribution for samples without and with a hole, respectively. - Highlights: • Tensile tests of plate specimens without and with a hole were performed. • Surface strain fields were in-situ observed by ARAMIS system. • Slip traces development on sample surfaces was in-situ observed by SEM. • The hole deteriorated both the tensile strength and elongation of the samples. • Tensile strength of specimens without and with a hole was discussed respectively.

  4. Postirradiation examination results for the Irradiation Effects Test 2

    International Nuclear Information System (INIS)

    Ploger, S.A.; Kerwin, D.K.; Croucher, D.W.

    1978-01-01

    This report presents the postirradiation examination results of Test IE-2 in the Irradiation Effects Test Series conducted under the Thermal Fuels Behavior Program. The objectives of this test were to evaluate the influence of previous cladding irradiation and fuel-cladding diametral gap on fuel rod behavior during a power ramp and during film boiling operation. Test IE-2, conducted in the Power Burst Facility at the Idaho National Engineering Laboratory, employed two 0.97-m-long pressurized water reactor type fuel rods fabricated from previously irradiated zircaloy-4 cladding and two similar rods fabricated from unirradiated cladding. The four rods were subjected to a preconditioning period, followed by a power ramp to an average peak rod power of 68 kW/m and steady state operation for one hour at an individual rod coolant mass flux of 4880 kg/s . m 2 . After a flow reduction to 2550 kg/s . m 2 , film boiling occurred on three rods. An additional flow reduction to 2245 kg/s . m 2 produced film boiling on the remaining fuel rod. Maximum time in film boiling was 90 s. None of the four fuel rods failed during the test. Damage caused by film boiling, as characterized by oxidation, oxide spalling, and collapse at fuel pellet interfaces, was found on all four rods. Film boiling regions on these rods showed evidence of fuel melting, fuel centerline void formation, and internal cladding oxidation resulting from fuel-cladding reaction. Effects of fuel-cladding diametral gap and cladding irradiation are summarized. Measured temperatures and metallographically estimated temperatures are compared at several axial fuel rod locations

  5. Improving High-Temperature Tensile and Low-Cycle Fatigue Behavior of Al-Si-Cu-Mg Alloys Through Micro-additions of Ti, V, and Zr

    Science.gov (United States)

    Shaha, S. K.; Czerwinski, F.; Kasprzak, W.; Friedman, J.; Chen, D. L.

    2015-07-01

    High-temperature tensile and low-cycle fatigue tests were performed to assess the influence of micro-additions of Ti, V, and Zr on the improvement of the Al-7Si-1Cu-0.5Mg (wt pct) alloy in the as-cast condition. Addition of transition metals led to modification of microstructure where in addition to conventional phases present in the Al-7Si-1Cu-0.5Mg base, new thermally stable micro-sized Zr-Ti-V-rich phases Al21.4Si4.1Ti3.5VZr3.9, Al6.7Si1.2TiZr1.8, Al2.8Si3.8V1.6Zr, and Al5.1Si35.4Ti1.6Zr5.7Fe were formed. The tensile tests showed that with increasing test temperature from 298 K to 673 K (25 °C to 400 °C), the yield stress and tensile strength of the present studied alloy decreased from 161 to 84 MPa and from 261 to 102 MPa, respectively. Also, the studied alloy exhibited 18, 12, and 5 pct higher tensile strength than the alloy A356, 354 and existing Al-Si-Cu-Mg alloy modified with additions of Zr, Ti, and Ni, respectively. The fatigue life of the studied alloy was substantially longer than those of the reference alloys A356 and the same Al-7Si-1Cu-0.5Mg base with minor additions of V, Zr, and Ti in the T6 condition. Fractographic analysis after tensile tests revealed that at the lower temperature up to 473 K (200 °C), the cleavage-type brittle fracture for the precipitates and ductile fracture for the matrix were dominant while at higher temperature fully ductile-type fracture with debonding and pull-out of cracked particles was identified. It is believed that the intermetallic precipitates containing Zr, Ti, and V improve the alloy performance at increased temperatures.

  6. Isothermal and isochronal annealing methodology to study post-irradiation temperature activated phenomena

    International Nuclear Information System (INIS)

    Chabrerie, C.; Autran, J.L.; Paillet, P.; Flament, O.; Leray, J.L.; Boudenot, J.C.

    1997-01-01

    In this work, the evolution of the oxide trapped charge has been modeled, to predict post-irradiation behavior for arbitrary anneal conditions (i.e., arbitrary temperature-time profiles). Using experimental data obtained from a single isochronal anneal, the method consists of calculating the evolution of the energy distribution of the oxide trapped charge, in the framework of a thermally activated charge detrapping model. This methodology is illustrated in this paper by the prediction of experimental isothermal data from isochronal measurements. The implications of these results to hardness assurance test methods are discussed

  7. Postirradiation examination results for the Irradiation Effects Test Series IE-ST-2, Rod IE-002

    International Nuclear Information System (INIS)

    Murdock, B.A.

    1977-12-01

    A postirradiation examination was conducted on a zircaloy-clad, UO 2 -fueled, pressurized water reactor (PWR) type rod which had been tested in the Power Burst Facility as part of the Irradiation Effects Test Series of the Thermal Fuels Behavior Program. The fuel rod, previously irradiated to a burnup of 15,800 MWd/t was subjected to a power ramp from 28 to 55 kW/m peak power at an average ramp rate of 4 kW/m/min. Posttest fuel restructuring and relocation, fission product redistribution, and fuel rod cladding deformation were evaluated and analyzed

  8. Piroxicam decreases postirradiation colonic neoplasia in the rat.

    Science.gov (United States)

    Northway, M G; Scobey, M W; Cassidy, K T; Geisinger, K R

    1990-12-01

    This study evaluated the effects of the nonsteroidal antiinflammatory agent piroxicam on chronic radiation proctitis in the rat. Forty female Wistar rats received a 2250-cGy dose of irradiation to the distal 2 cm of the colon. Twenty received piroxicam 8.0 mg/kg orally 30 minutes before exposure and 24 hours after exposure; 20 rats served as irradiated controls. All animals were evaluated by colonoscopy 1 and 3 weeks postexposure and every third week until death or killing at 1 year. At killing, colons were removed for light microscopic examination. One year postirradiation results showed no differences in mortality, vascular changes, acute inflammation, colitis cystica profunda, or rectal stricture between the control and piroxicam-treated groups. However, at 1 year postirradiation the control group demonstrated neoplasia in 15 of 19 animals compared with eight of 20 animals in the piroxicam-treated group. The first endoscopic appearance of colonic neoplasm occurred at 15 weeks postirradiation in one control irradiated rat whereas the first evidence of endoscopic neoplasm in the piroxicam-treated group did not occur until 36 weeks postirradiation. Histologic examination documented a tendency toward a greater presence of adenocarcinomas in the control group compared with the piroxicam-treated group. The authors conclude that piroxicam treatment significantly decreased the incidence of colonic neoplasia in general as well as delayed the endoscopic appearance of colonic neoplasia in rats after pelvic irradiation.

  9. Piroxicam decreases postirradiation colonic neoplasia in the rat

    International Nuclear Information System (INIS)

    Northway, M.G.; Scobey, M.W.; Cassidy, K.T.; Geisinger, K.R.

    1990-01-01

    This study evaluated the effects of the nonsteroidal antiinflammatory agent piroxicam on chronic radiation proctitis in the rat. Forty female Wistar rats received a 2250-cGy dose of irradiation to the distal 2 cm of the colon. Twenty received piroxicam 8.0 mg/kg orally 30 minutes before exposure and 24 hours after exposure; 20 rats served as irradiated controls. All animals were evaluated by colonoscopy 1 and 3 weeks postexposure and every third week until death or killing at 1 year. At killing, colons were removed for light microscopic examination. One year postirradiation results showed no differences in mortality, vascular changes, acute inflammation, colitis cystica profunda, or rectal stricture between the control and piroxicam-treated groups. However, at 1 year postirradiation the control group demonstrated neoplasia in 15 of 19 animals compared with eight of 20 animals in the piroxicam-treated group. The first endoscopic appearance of colonic neoplasm occurred at 15 weeks postirradiation in one control irradiated rat whereas the first evidence of endoscopic neoplasm in the piroxicam-treated group did not occur until 36 weeks postirradiation. Histologic examination documented a tendency toward a greater presence of adenocarcinomas in the control group compared with the piroxicam-treated group. The authors conclude that piroxicam treatment significantly decreased the incidence of colonic neoplasia in general as well as delayed the endoscopic appearance of colonic neoplasia in rats after pelvic irradiation. 41 references

  10. Piroxicam decreases postirradiation colonic neoplasia in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Northway, M.G.; Scobey, M.W.; Cassidy, K.T.; Geisinger, K.R. (Wake Forest Univ., Winston Salem, NC (USA))

    1990-12-01

    This study evaluated the effects of the nonsteroidal antiinflammatory agent piroxicam on chronic radiation proctitis in the rat. Forty female Wistar rats received a 2250-cGy dose of irradiation to the distal 2 cm of the colon. Twenty received piroxicam 8.0 mg/kg orally 30 minutes before exposure and 24 hours after exposure; 20 rats served as irradiated controls. All animals were evaluated by colonoscopy 1 and 3 weeks postexposure and every third week until death or killing at 1 year. At killing, colons were removed for light microscopic examination. One year postirradiation results showed no differences in mortality, vascular changes, acute inflammation, colitis cystica profunda, or rectal stricture between the control and piroxicam-treated groups. However, at 1 year postirradiation the control group demonstrated neoplasia in 15 of 19 animals compared with eight of 20 animals in the piroxicam-treated group. The first endoscopic appearance of colonic neoplasm occurred at 15 weeks postirradiation in one control irradiated rat whereas the first evidence of endoscopic neoplasm in the piroxicam-treated group did not occur until 36 weeks postirradiation. Histologic examination documented a tendency toward a greater presence of adenocarcinomas in the control group compared with the piroxicam-treated group. The authors conclude that piroxicam treatment significantly decreased the incidence of colonic neoplasia in general as well as delayed the endoscopic appearance of colonic neoplasia in rats after pelvic irradiation. 41 references.

  11. Effect of Annealing Temperature on the Microstructure, Tensile Properties, and Fracture Behavior of Cold-Rolled High-Mn Light-Weight Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Hyun; Cho, Kyung Mox [Pusan National University, Busan (Korea, Republic of); Park, Seong-Jun; Moon, Joonoh; Kang, Jun-Yun; Park, Jun-Young; Lee, Tae-Ho [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2017-05-15

    The effects of the annealing temperature on the microstructure and tensile properties of cold-rolled light-weight steels are investigated using two Fe-30Mn-xAl-0.9C alloys that contain different Al content. The initial alloy microstructure is composed of a single austenite or a mixture of austenite and ferrite depending on the nominal aluminum content. For the alloy with 9 wt%Al content, the recrystallization and grain growth of austenite occurrs depending on the annealing temperature. However, for the alloy with 11 wt%Al content, the β-Mn phase is observed after annealing for 10 min at 550~800 ℃. The β-Mn transformation kinetics is the fastest at 700 ℃. The formation of the β-Mn phase has a detrimental effect on the ductility, and this leads to significant decreases in the total elongation. The same alloy also forms κ-carbide and DO3 ordering at 550~900 ℃. The investigated alloys exhibit a fully recrystallized microstructure after annealing at 900 ℃ for 10 min, which results in a high total elongation of 25~55%with a high tensile strength of 900~1170 MPa.

  12. New Therapeutic Possibilities of the Post-Irradiation Haemorrhagic Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Pospisil, J.; Dienstbier, Z. [Institute of Biophysics and Nuclear Medicine, Faculty of General Medicine, Charles University, Prague, Czechoslovak Socialist Republic (Czech Republic); Skala, E. [Central Military Hospital, Prague-Stresovice, Czechoslovak Socialist Republic (Czech Republic)

    1969-10-15

    Haemorrhagic diathesis is one of the dominant symptoms of acute post-irradiation lesion. Haemorrhagic syndrome is caused by the disturbance of haemocoagulation during simultaneous lesion of the vascular system. In our study we have tried to affect the post-irradiation haemocoagulation disturbance. Epsilon- amino-caproic acid (EACA) administered between the 8{sup th} and the 18{sup th} day (0.4 g/kg per day) to whole- body irradiated dogs (600 R) partially regulated the post-irradiation disturbance of haemocoagulation. The favourable effect of EACA was verified by in vitro experiments in which the blood of irradiated dogs was used. A repeated administration of EACA in the dose of 0.4 g/kg per day to whole-body irradiated rats (600 R) did not substantially affect the post-irradiation changes in the number of white blood elements; however, its administration to healthy animals caused lymphocytosis. In whole-body irradiated dogs (600 R) we have found lower levels of EACA in the blood up to the 8 day following irradiation as compared with healthy dogs after oral application of EACA. The whole-body irradiation of mice did not increase the acute toxicity of EACA. The daily administration of 0.4 g EACA/kg to whole-body irradiated mice (600 and 700 R) did not change the mortality induced by irradiation. The authors consider EACA to be a suitable compound for a complex therapy of radiation sickness. The administration of para-amino-methyl-benzoic acid (PAMBA), in spite of a certain improvement of postirradiation haemocoagulation disturbance, is less efficient. Our recent experiments with ellagic acid which significantly affects the post-traumatic haemorrhage in whole-body irradiated rats seem to be very promising. (author)

  13. Mechanical properties of Zr-2.5Nb pressure tube material manufactured employing forging routes for PHWR700 - Part 1: tensile behavior

    International Nuclear Information System (INIS)

    Bind, A.K.; Singh, R.N.; Sunil, Saurav; Chakravartty, J.K.; Ghosh, Agnish; Dhandharia, Priyesh; More, Nitin S.; Vijayakumar, S.; Chhatre, A.G.

    2012-01-01

    Tensile properties of Zr-2.5Nb alloy tubes produced employing forging to break the cast structure were evaluated by carrying out uni-axial tension test at temperatures between 25 and 325 degC and under strain-rate of 1.075 x 10 -4 /s for both longitudinal and transverse specimens. Both strength and elongation values were comparable for the samples obtained from front and back end of the tube. Transverse samples showed higher strength and lower uniform elongation values as compared to longitudinal samples. The yield strength of double forged material at 25 degC is higher than the PHWR700 specification of a maximum value of 586 MPa. (author)

  14. Modeling the Monotonic and Cyclic Tensile Stress-Strain Behavior of 2D and 2.5D Woven C/SiC Ceramic-Matrix Composites

    Science.gov (United States)

    Li, L. B.

    2018-05-01

    The deformation of 2D and 2.5 C/SiC woven ceramic-matrix composites (CMCs) in monotonic and cyclic loadings has been investigated. Statistical matrix multicracking and fiber failure models and the fracture mechanics interface debonding approach are used to determine the spacing of matrix cracks, the debonded length of interface, and the fraction of broken fibers. The effects of fiber volume fraction and fiber Weibull modulus on the damage evolution in the composites and on their tensile stress-strain curves are analyzed. When matrix multicracking and fiber/matrix interface debonding occur, the fiber slippage relative to the matrix in the debonded interface region of the 0° warp yarns is the main reason for the emergance of stress-strain hysteresis loops for 2D and 2.5D woven CMCs. A model of these loops is developed, and histeresis loops for the composites in cyclic loadings/unloadings are predicted.

  15. Microstructure evolution of titanium after tensile test

    International Nuclear Information System (INIS)

    Wronski, S.; Wierzbanowski, K.; Jędrychowski, M.; Tarasiuk, J; Wronski, M.; Baczmanski, A.; Bacroix, B.

    2016-01-01

    The qualitative and quantitative behavior of titanium T40 during tensile loading with a special emphasis on the presence of deformation twins in the observed microstructures is described. The samples for tensile tests were cut out from the rolled titanium sheet along the rolling and transverse directions. Several microstructure maps were determined using Electron Backscatter Diffraction technique (EBSD). These data were used to obtain crystallographic textures, misorientation distributions, grain size, twin boundary length, grain orientation spread, low and high angle boundary fractions and Schmid and Taylor factors. The deformation mechanisms and microstructure characteristics are different in the samples stretched along rolling and transverse directions. A strong appearance of tensile twins was observed in the samples deformed along transverse direction. On the other hand, more frequent subgrain formation and higher orientation spread was observed in the sample deformed along rolling direction, which caused’‘orientation blurring’ leading to an increase of grain size with deformation, as determined from OIM analysis.

  16. In Situ Radiography During Tensile Tests

    Science.gov (United States)

    Baaklini, George Y.; Bhatt, Ramakrishna T.

    1994-01-01

    Laboratory system for testing specimens of metal-, ceramic-, and intermetallic-matrix composite materials incorporates both electromechanical tensile-testing subsystem and either of two imaging subsystems that take x-ray photographs of specimens before, during, and after tensile tests. Used to test specimens of reaction-bonded silicon nitride reinforced with silicon carbide fibers (SiC/RBSN) considered for high-temperature service in advanced aircraft turbine engines. Provides data on effects of preexisting flaws (e.g., high-density impurities and local variations of density) on fracture behavior. Accumulated internal damage monitored during loading. X-ray source illuminates specimen in load frame while specimen is pulled. X-ray images on film correlated with stress-vs.-strain data from tensile test.

  17. Postirradiation examination of high-U-loaded, low-enriched U3O8, UAl2, and U3Si test fuel plates

    International Nuclear Information System (INIS)

    Gomez, J.; Morando, R.; Perez, E.E.; Giorsetti, D.R.; Copeland, G.L.; Hofman, G.L.; Snelgrove, J.L.

    1985-01-01

    The scope of this work is to present an evaluation of the postirradiation examination of the second set of high-U-loaded, low-enriched U 3 O 8 , UAl 2 and U 3 Si miniature plates manufactured by the Comision Nacional de Energia Atomica (CNEA) of Argentina, and irradiated and examined, within the framework of the Reduced Enrichment Research and Test Reactor (RERTR) Program, at Oak Ridge National Laboratory and Argonne National Laboratory. This paper includes fabrication details of the plates, their irradiation history and the results of postirradiation examination which are compared to those of the previous test and to present results from other laboratories participating in the RERTR Program. Postirradiation examination of these plates showed satisfactory performance for the oxides, aluminides and silicides (except for the highest-loaded U 3 Si plate) with the only indication of detrimental behavior being the slight bowing of some plates at about 80% burnup

  18. Postirradiation examination of high-U-loaded, low-enriched U3O8, UAl2, and U3Si test fuel plates

    International Nuclear Information System (INIS)

    Gomez, J.; Morando, R.; Perez, E.E.; Giorsetti, D.R.; Copeland, G.L.; Hofman, G.L.; Snelgrove, J.L.

    1985-01-01

    The scope of this work is to present an evaluation of the postirradiation examination of the second set of high-U-loaded, low-enriched U 3 O 8 , UAl 2 and U 3 Si miniature plates manufactured by the Comision Nacional de Energia Atomica (CNEA) of Argentina, and irradiated and examined, within the framework of the Reduced Enrichment Research and Test Reactor (RERTR) Program, at Oak Ridge National Laboratory and Argonne National Laboratory. This paper includes fabrication details of the plates, their irradiation history and the results of postirradiation examination which are compared to those of the previous test and to present results from other laboratories participating in the REM Program. Postirradiation examination of these plates showed satisfactory performance for the oxides, aluminides and silicides (except for the highest-loaded U 3 Si plate) with the only indication of detrimental behavior being the slight bowing of some plates at about 80% burnup. (author)

  19. Postirradiation examination of high-U-loaded low-enriched U3O8, UAl2, and U3Si test fuel plates

    International Nuclear Information System (INIS)

    Gomez, J.; Morando, R.; Perez, E.E.; Giorsetti, D.R.; Copeland, G.L.; Hofmann, G.; Snelgrove, J.L.

    1984-01-01

    The scope of this work is to present an evaluation of the postirradiation examination of the second set of high-U-loaded low-enriched U 3 O 8 , UAl 2 and U 3 Si miniature plates manufactured by the Comision Nacional de Energia Atomica (CNEA) of Argentina, and irradiated and examinated, within the framework of the Reduced Enrichment Research and Test Reactor (RERTR) Program, at Oak Ridge National Laboratory and Argonne National Laboratory. This paper includes fabrication details of the plates, their irradiation history and the results of postirradiation examination which are compared to those of the previous test and to present results from other laboratories participating in the RERTR Program. Postirradiation examination of these plates showed satisfactory poerformance for the oxides, aluminides and silicides (except for the highest-loaded U 3 Si plate) with the only indication of detrimental behavior during the slight bowing of some plates at about 80% burnup

  20. Effect of mushy state rolling on age-hardening and tensile behavior of Al-4.5Cu alloy and in situ Al-4.5Cu-5TiB2 composite

    International Nuclear Information System (INIS)

    Siddhalingeshwar, I.G.; Herbert, M.A.; Chakraborty, M.; Mitra, R.

    2011-01-01

    Research highlights: → Mushy state rolling of composites reduces peak-aging times to ∼7.5-10% of that of as-cast alloy. → Uniform Cu atom distribution achieved in matrices by mushy state rolling enhances aging kinetics. → Uniform precipitate distribution obtained by mushy state rolling leads to higher microhardness. → Peak-age tensile strength and strain hardening rates are found to increase on mushy state rolling. - Abstract: The effect of mushy state rolling on aging kinetics of stir-cast Al-4.5Cu alloy and in situ Al-4.5Cu-5TiB 2 composite and their tensile behavior in solution-treated (495 deg. C) or differently aged (170 deg. C) conditions, has been investigated. As-cast or pre-hot rolled alloy and composite samples were subjected to single or multiple mushy state roll passes to 5% thickness reduction at temperatures for 20% liquid content. Peak-aging times of mushy state rolled composite matrices have been found as ∼7.5-10% of that of as-cast alloy. Such enhancement in aging kinetics is attributed to homogeneity in Cu atom distribution as well as increase in matrix dislocation density due to thermal expansion coefficient mismatch between Al and TiB 2 , matrix grain refinement and particle redistribution, achieved by mushy state rolling. Uniform precipitate distribution in mushy state rolled composite matrices leads to greater peak-age microhardness with higher yield and ultimate tensile strengths than those in as-cast alloy and composite.

  1. KEY RESULTS FROM IRRADIATION AND POST-IRRADIATION EXAMINATION OF AGR-1 UCO TRISO FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul A.; Hunn, John D.; Petti, David A.; Morris, Robert N.

    2016-11-01

    The AGR-1 irradiation experiment was performed as the first test of tristructural isotropic (TRISO) fuel in the US Advanced Gas Reactor Fuel Development and Qualification Program. The experiment consisted of 72 right cylinder fuel compacts containing approximately 3×105 coated fuel particles with uranium oxide/uranium carbide (UCO) fuel kernels. The fuel was irradiated in the Advanced Test Reactor for a total of 620 effective full power days. Fuel burnup ranged from 11.3 to 19.6% fissions per initial metal atom and time average, volume average irradiation temperatures of the individual compacts ranged from 955 to 1136°C. This paper focuses on key results from the irradiation and post-irradiation examination, which revealed a robust fuel with excellent performance characteristics under the conditions tested and have significantly improved the understanding of UCO coated particle fuel irradiation behavior within the US program. The fuel exhibited a very low incidence of TRISO coating failure during irradiation and post-irradiation safety testing at temperatures up to 1800°C. Advanced PIE methods have allowed particles with SiC coating failure to be isolated and meticulously examined, which has elucidated the specific causes of SiC failure in these specimens. The level of fission product release from the fuel during irradiation and post-irradiation safety testing has been studied in detail. Results indicated very low release of krypton and cesium through intact SiC and modest release of europium and strontium, while also confirming the potential for significant silver release through the coatings depending on irradiation conditions. Focused study of fission products within the coating layers of irradiated particles down to nanometer length scales has provided new insights into fission product transport through the coating layers and the role various fission products may have on coating integrity. The broader implications of these results and the application of

  2. Irradiation history and final postirradiation data for IFA-432

    International Nuclear Information System (INIS)

    Lanning, D.D.

    1986-11-01

    The irradiation history and final postirradiation examination (PIE) results are presented for the Halden fuel assembly IFA-432. In particular, the three instrumented rods (Rods 2, 3, and 5) that continued to the highest burnup (46 MWd/kgM) are emphasized. The long survival rate of the fuel instrumentation allowed a continuous record to be kept of linear heat generation rate and fuel temperatures throughout the operating history of the asembly. Fission gas release was estimated based on a combination of gas retention and ceramographic data. The PIE data show that the postirradiation condition of the rods is qualitatively consistent with the power/temperature histories experienced. Fission gas release estimates are: Rod 2 (380 μm as-fabricated gap), 20-40%; Rod 5 (230 μm as-fabricated gap), 20-40%; and Rod 3 (76 μm as-fabricated gap), 0-20%

  3. Advanced Post-Irradiation Examination Capabilities Alternatives Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Bryan; Bill Landman; Porter Hill

    2012-12-01

    An alternatives analysis was performed for the Advanced Post-Irradiation Capabilities (APIEC) project in accordance with the U.S. Department of Energy (DOE) Order DOE O 413.3B, “Program and Project Management for the Acquisition of Capital Assets”. The Alternatives Analysis considered six major alternatives: ? No Action ? Modify Existing DOE Facilities – capabilities distributed among multiple locations ? Modify Existing DOE Facilities – capabilities consolidated at a few locations ? Construct New Facility ? Commercial Partnership ? International Partnerships Based on the alternatives analysis documented herein, it is recommended to DOE that the advanced post-irradiation examination capabilities be provided by a new facility constructed at the Materials and Fuels Complex at the Idaho National Laboratory.

  4. Postirradiation examination results from the LP-FP-2 center fuel module

    International Nuclear Information System (INIS)

    Jensen, S.M.; Akers, D.W.

    1990-01-01

    The LP-FP-2 experiment was conducted on July 9, 1985 in the Loss of Fluid Test (LOFT) facility located at the Idaho National Engineering Laboratory (INEL). The primary purpose of this experiment was to provide information of the release, transport, and deposition of fission products and aerosols during a sever core damage event performed in a large scale nuclear reactor facility. Postirradiation nondestructive and destructive examinations of the fuel bundle provided information to assist in achieving this objective, as well as providing information on the material behavior and interactions that occurred within the fuel bundle during this sever core damage experiment. This was a large-scale integral test, incorporating an 11 x 11 array of fuel rods, control rods, and instrumentation tubes, with an active core length of 1.68 m. Peak temperatures in the fuel bundle exceeded 2100 K or approximately 4.5 min, with localized peak temperatures exceeding the melting point of the UO 2 fuel (3120 K). Large amounts of zircaloy oxidation and material relocation occurred during the experiment. The transient phase was terminated by a rapid reflood of cooling water, which resulted in significant oxidation and hydrogen generation. Zircaloy oxidation during the reflood period caused a rapid temperature excursion to occur in the upper two-thirds of the fuel bundle. This article summarizes the data and analysis from the postirradiation examinations of the LP-FP-2 fuel bundle. 12 refs., 39 figs., 8 tabs

  5. Use of unstable chromosome aberrations for biological dosimetry after the first postirradiation mitosis

    International Nuclear Information System (INIS)

    Doloy, M.T.; Malarbet, J.L.; Guedeney, G.; Bourguignon, M.; Leroy, A.; Reillaudou, M.; Masse, R.

    1991-01-01

    The loss of unstable chromosome aberrations after the first postirradiation mitosis makes their use difficult in radiation dosimetry. We describe here a method which, in a cell population observed at this stage, allows retrospective estimation of the frequencies of the unstable aberrations induced at the time of irradiation, and their use as a dosimeter. The laws controlling the behavior of unstable aberrations during mitosis were defined from a large-scale experiment on irradiated human lymphocytes. For cells undergoing the first, second, or third mitosis after irradiation, relationships were determined between the frequency, at irradiation time, of acentric fragments not arising from formation of dicentrics or rings, and the ratio of dicentrics and centric rings appearing without acentric fragments to the total number of dicentrics plus rings. On the basis of this ratio, the method described here provides an assessment of the postirradiation mitotic activity in a cell population. This assessment permitted estimation of the cell distribution and frequency of dicentrics plus centric rings, and of the frequency of acentric fragments at the time of irradiation. The use of this method for retrospective dosimetry after whole-body irradiation under various conditions of exposure is illustrated

  6. swelling characteristics and tensile properties of natural fiber rei

    African Journals Online (AJOL)

    USER

    The swelling behavior and tensile strength of natural fiber-reinforced plastic in premium motor spirit (PMS), dual ... with fibers usually of glass fiber, Kevlar and carbon have gained ... NIGERIAN JOURNAL OF TECHNOLOGY, VOL. 27 NO.2 ...

  7. In situ formation of ZrB2 particulates and their influence on microstructure and tensile behavior of AA7075 aluminum matrix composites

    Directory of Open Access Journals (Sweden)

    J. David Raja Selvam

    2017-02-01

    Full Text Available In situ synthesis of aluminum matrix composites (AMCs has become a popular method due to several advantages over conventional stir casting method. In the present study, AA7075/ZrB2 AMCs reinforced with various content of ZrB2 particulates (0, 3, 6, 9 and 12 wt.% were synthesized by the in situ reaction of molten aluminum with inorganic salts K2ZrF6 and KBF4. The composites were characterized using XRD, OM, SEM, EBSD and TEM. The XRD patterns revealed the formation of ZrB2 particulates without the presence of any other compounds. The formation of ZrB2 particulates refined the grains of aluminum matrix extensively. Most of the ZrB2 particulates were located near the grain boundaries. The ZrB2 particulates exhibited various morphologies including spherical, cylindrical and hexagonal shapes. The size of the ZrB2 particulates was in the order of nano, sub micron and micron level. A good interfacial bonding was observed between the aluminum matrix and the ZrB2 particulates. The in situ formed ZrB2 particulates enhanced the mechanical properties such as microhardness and the ultimate tensile strength. Various strengthening mechanisms were identified.

  8. Effects of torsional oscillation on tensile behavior of Sn–3.5 wt% Ag alloy with and without adding ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sobhy, M., E-mail: miladsobhym@yahoo.com

    2014-07-29

    Stress–strain characteristics of both Sn–3.5 wt% Ag and Sn–3.5 wt% Ag–0.3 wt% ZnO alloys were investigated using tensile testing machine. Different superimposed torsional oscillation frequencies ranging from 0 to 1.3 Hz at different deformation temperatures ranging from 303 to 363 K were performed. X-ray diffraction (XRD), transition electron microscopy (TEM) and optical microscopy were used to investigate the microstructures of both alloys. The mechanical parameters such as Young's modulus Y, yield stress σ{sub y}, fracture stress σ{sub f}, work hardening coefficient χ{sub p} and fracture strain ε{sub f} were calculated. The fracture stress of both alloys decreases with increasing the superimposed frequency of torsional oscillations as well as deformation temperatures. The fracture strain behaves in a different manner i.e. it increases with increasing the deformation temperature in the alloy containing ZnO nanoparticles while decreases in the alloy free from ZnO nanoparticles. With respect to the effect of the frequency of the superimposed torsional deformation, the fracture strain increases in both alloys.

  9. On the mechanism of rapid postirradiation recovery of yeast

    International Nuclear Information System (INIS)

    Glazunov, A.V.; Kapul'tsevich, Yu.G.

    1983-01-01

    Rapid postirradiation recovery of diploid yeast Saccharomyces cerevisiae is equally effective both in water and in a liquid nutrition medium. In the haploid strains, rapid recovery occurs more readily in the log phase than in the stationary phase of growth. In the diploid strains, rapid recovery is more effective in the log phase than in the stationary phase. Rapid recovery of yeast does not require an additional protein synthesis. Damages induced by UV-light are not sub ected to rapid recovery

  10. Processes in N-channel MOSFETs during postirradiation thermal annealing

    International Nuclear Information System (INIS)

    Pejovic, M.; Jaksic, A.; Ristic, G.; Baljosevic, B.

    1997-01-01

    The processes during postirradiation thermal annealing of γ-ray irradiated n-channel MOSFETs with both wet and dry gate oxides are investigated. For both analysed technologies, a so-called ''latent'' interface trap buildup is observed, followed at very late annealing times by the decrease in the interface-trap density. A model is proposed that successfully accounts for the experimental results. Implications of observed effects for total dose hardness assurance test methods implementation are discussed. (author)

  11. A mechanistic approach to postirradiation spoilage kinetics of fish

    International Nuclear Information System (INIS)

    Tukenmez, I.

    2004-01-01

    Full text: In order to simulate postirradiation spoilage of fish, the mechanistic aspects of the growth of surviving microorganisms during chill storage and their product formation in irradiated fish were analyzed. Anchovy (Engraulis encrasicholus) samples those unirradiated and irradiated at 1, 2 and 3 kGy doses of gamma radiation were stored at +2 o C for 21 days. Total bacterial counts (TBC) and trimethylamine (TMA) analysis of the samples were done periodically during storage. Depending on the proposed spoilage mechanism, kinetic model equations were derived. By using experimental data of TBC and TMA in the developed model, the postirradiation spoilage parameters including growth rate constant, inital and maximum attainable TBC, lag time and TMA yield were evaluated and microbial spoilage of fish was simulated for postirradiation storage. Shelf life of irradiated fish was estimated depending on the spoilage kinetics. Dose effects on the kinetic parameters were analyzed. It is suggested that the kinetic evaluation method developed in this study may be used for quality assessment, shelf life determination and dose optimization for radiation preservation of fish

  12. Post-irradiation stability of polyvinyl chloride at sterilizing doses

    International Nuclear Information System (INIS)

    Naimian, F.; Katbab, A.A.; Nazokdast, H.

    1994-01-01

    Post-irradiation stability of plasticized PVC irradiated by 60 Co gamma ray at sterilizing doses has been studied. Effects of irradiation upon chemical structure, mechanical properties and rheological behaviour of samples contained different amounts of Di(2-ethylhexyl)phthalate as plasticizer have been investigated. Formation of conjugated double bonds, carbonyl and hydroxyl groups have been followed by UV and FTIR spectrometers up to 6 months after irradiation. FTIR spectra of irradiated samples showed no significant changes in carbonyl and hydroxyl groups even 6 months after irradiation. However, changes in UV-visible spectra was observed for the irradiated samples up to 6 months post-irradiation. This has been attributed to the formation of polyenes which leads to the discoloration of this polymer. Despite a certain degree of discoloration, it appears that the mechanical properties of PVC are not affected by irradiation at sterilizing doses. No change in the melt viscosity of the irradiated PVC samples with post-irradiation was observed, which is inconsistent with the IR results. (author)

  13. Postirradiation DNA synthesis is inversely related to cell survival

    International Nuclear Information System (INIS)

    Kapiszewska, M.; Lange, C.S.

    1987-01-01

    Postirradiation (PI) events which might lead to cellular reproductive death or survival were studied in L5178Y-S (LY-S) cells. PI incubation at 25 0 C protects LY-S cells against the PLD fixation which takes place at 37 0 C. An optimal condition for the repair of PLD is 1h at 37 0 C followed by 4h holding at 25 0 C prior to the second half of a split dose, or 5L holding at 25 0 C without a 37 0 C incubation. Longer incubations at 37 0 C resulted in progressively decreased survivals. Postirradiation inhibition of DNA synthesis at 37 0 C was observed only during the first 30 min; thereafter, /sup 3/H-dThd incorporation was higher than in unirradiated controls. This excess synthesis effect was removed by shifting irradiated cells to 25 0 C holding. The inhibition observed at 25 0 C was reversed by shifting to 37 0 C. Thus the degree of postirradiation DNA synthesis is inversely related to PLD/SLD repair. DNA filter elution shows complete SSB repair by 3h at both temperatures (with faster kinetics at 37 0 C), and DSB repair plateaus at 80% (37 0 C) and 60% (25 0 C) after 90 min

  14. Post-irradiation examination of fuel elements of Tarapur Atomic Power Station (Report-I)

    International Nuclear Information System (INIS)

    Bahl, J.K.; Sah, D.N.; Chatterjee, S.; Sivaramkrishnan, K.S.

    1979-01-01

    Detailed post-irradiation examination of three initial load fuel elements of the Tarapur Atomic Power Station (TAPS) has been carried out. The causes of the element failures have been analysed. It was observed that almost 90% of the length of the elements exoerienced nodular corrosion. It has been estimated that nodular corrosion would seriously affect the wall thickness and surface temperature of higher rated elements. Lunar shaped fret marks have also been observed at some spacer grid locations in the elements. The depth of the largest fret mark was measured to be 16.9% clad wall thickness. Detailed metallographic examination of the clad and fuel in the three elements has been done. The temperatures at different structural regions of the fuel cross-sections have been estimated. The change in fuel density during irradiation has been evaluated by comparing the irradiated fuel diameter with the mean pellet design diameter. The performance of the end plug welds and spacer grid sites in the elements has been assessed. The burnup distribution along the length of the elements has been evaluated by gamma scanning. The redistribution of fission products in the fuel has been examined by gamma scanning and beta-gamma autoradiography. Mechanical properties of the irradiated cladding have been examined by ring tensile testing. (auth.)

  15. Thermal properties of graphene under tensile stress

    Science.gov (United States)

    Herrero, Carlos P.; Ramírez, Rafael

    2018-05-01

    Thermal properties of graphene display peculiar characteristics associated to the two-dimensional nature of this crystalline membrane. These properties can be changed and tuned in the presence of applied stresses, both tensile and compressive. Here, we study graphene monolayers under tensile stress by using path-integral molecular dynamics (PIMD) simulations, which allows one to take into account quantization of vibrational modes and analyze the effect of anharmonicity on physical observables. The influence of the elastic energy due to strain in the crystalline membrane is studied for increasing tensile stress and for rising temperature (thermal expansion). We analyze the internal energy, enthalpy, and specific heat of graphene, and compare the results obtained from PIMD simulations with those given by a harmonic approximation for the vibrational modes. This approximation turns out to be precise at low temperatures, and deteriorates as temperature and pressure are increased. At low temperature, the specific heat changes as cp˜T for stress-free graphene, and evolves to a dependence cp˜T2 as the tensile stress is increased. Structural and thermodynamic properties display non-negligible quantum effects, even at temperatures higher than 300 K. Moreover, differences in the behavior of the in-plane and real areas of graphene are discussed, along with their associated properties. These differences show up clearly in the corresponding compressibility and thermal expansion coefficient.

  16. Influence of ZnO nano-particles addition on thermal analysis, microstructure evolution and tensile behavior of Sn–5.0 wt% Sb–0.5 wt% Cu lead-free solder alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.N., E-mail: alynabieh@yahoo.com [Physics Department, Faculty of Science, Suez-Canal University, 41522 Ismailia (Egypt); Eid, E.A., E-mail: dr_eid_hti@yahoo.com [Basic Science Department, Higher Technological Institute, 44629 10th of Ramadan City (Egypt)

    2015-04-24

    Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT{sub m}=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ{sub YS} by ~12% and improved the ultimate tensile strength σ{sub UTS} by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder. - Highlights: • Melting point of SSC505-ZnO composite solder is slightly increased by 0.89 {sup ο}C compared with the plain SSC505 solder. • XRD and EDX analysis reflect the presence of SbSn, Cu{sub 6}Sn{sub 5} IMCs. • EF-SEM images of SSC-ZnO composite solder revealed homogenous uniform distribution of β-Sn grains and fine IMC particles. • A detectable improvement in the Young modulus, ultimate tensile strength and yield strength were observed after addition of 0.5 wt% ZnO nano-metric particles.

  17. Post-Irradiation Non-Destructive Analyses of the AFIP-7 Experiment

    Science.gov (United States)

    Williams, W. J.; Robinson, A. B.; Rabin, B. H.

    2017-12-01

    This article reports the results and interpretation of post-irradiation non-destructive examinations performed on four curved full-size fuel plates that comprise the AFIP-7 experiment. These fuel plates, having a U-10 wt.%Mo monolithic design, were irradiated under moderate operating conditions in the Advanced Test Reactor to assess fuel performance for geometries that are prototypic of research reactor fuel assemblies. Non-destructive examinations include visual examination, neutron radiography, profilometry, and precision gamma scanning. This article evaluates the qualitative and quantitative data taken for each plate, compares corresponding data sets, and presents the results of swelling analyses. These characterization results demonstrate that the fuel meets established irradiation performance requirements for mechanical integrity, geometric stability, and stable and predictable behavior.

  18. Quantitative analysis of tensile deformation behavior by in-situ neutron diffraction for ferrite-martensite type dual-phase steels

    International Nuclear Information System (INIS)

    Morooka, Satoshi; Umezawa, Osamu; Harjo, Stefanus; Hasegawa, Kohei; Toji, Yuki

    2012-01-01

    The yielding and work-hardening behavior of ferrite-martensite type dual-phase (DP) alloys were clearly analyzed using the in-situ neutron diffraction technique. We successfully established a new method to estimate the stress and strain partitioning between ferrite and martensite phase during loading. Although these phases exhibit the same lattice structure with similar lattice parameters, their lattice strains on (110), (200) and (211) are obviously different from each other under an applied stress. The misfit strains between those phases were clearly accompanied with the phase-scaled internal stream (phase stress). Thus, the martensite phase yielded by higher applied stress than macro-yield stress, which resulted in high work-hardening rate of the DP steel. We also demonstrated that ferrite phase fraction influenced work-hardening behavior. (author)

  19. Post-irradiation examination and R and D programs using irradiated fuels at KAERI

    International Nuclear Information System (INIS)

    Chun, Yong Bum; Min, Duck Kee; Kim, Eun Ka and others

    2000-12-01

    This report describes the Post-Irradiation Examination(PIE) and R and D programs using irradiated fuels at KAERI. The objectives of post-irradiation examination (PIE) for the PWR irradiated fuels, CANDU fuels, HANARO fuels and test fuel materials are to verify the irradiation performance and their integrity as well as to construct a fuel performance data base. The comprehensive utilization program of the KAERI's post-irradiation examination related nuclear facilities such as Post-Irradiation Examination Facility (PIEF), Irradiated Materials Examination Facility (IMEF) and HANARO is described

  20. Post-irradiation examination and R and D programs using irradiated fuels at KAERI

    International Nuclear Information System (INIS)

    Chun, Yong Bum; So, Dong Sup; Lee, Byung Doo; Lee, Song Ho; Min, Duck Kee

    2001-09-01

    This report describes the Post-Irradiation Examination(PIE) and R and D programs using irradiated fuels at KAERI. The objectives of post-irradiation examination (PIE) for the PWR irradiated fuels, CANDU fuels, HANARO fuels and test fuel materials are to verify the irradiation performance and their integrity as well as to construct a fuel performance data base. The comprehensive utilization program of the KAERI's post-irradiation examination related nuclear facilities such as Post-Irradiation Examination Facility (PIEF), Irradiated Materials Examination Facility (IMEF) and HANARO is described

  1. Post-irradiation handling and examination at the HFEF complex

    International Nuclear Information System (INIS)

    Bacca, J.P.

    1980-01-01

    The Hot Fuel Examination Facility provides postirradiation handling and examination of fast reactor irradiation experiments and safety tests for the United States Breeder Reactor Program. Nondestructive interim examinations and destructive terminal examinations at HFEF derive data from tests irradiated in the Experimental Breeder Reactor No. II, in the Transient Reactor Test Facility (TREAT), and in the Sodium Loop Safety Facility. Similar support will be provided in the near future for tests irradiated in the Fast Flux Test Facility, and for the larger sodium loops to be irradiated in TREAT

  2. Postirradiation lesions of the brachial plexus. Results of surgical treatment

    International Nuclear Information System (INIS)

    LeQuang, C.

    1989-01-01

    In a series of 103 cases of postirradiation lesions of the brachial plexus operated on between 1978 and 1986--of which 60 patients have been reviewed with a follow up from 2 to 9 years--the surgical results are analyzed according to an anatomic classification, a clinical classification, and the surgical procedures. We conclude that the radiation plexitis should be treated surgically and at the earliest possible time after the onset of paresthesias. Also, the surgical procedure which gives the best results is neurolysis with pedicled omentoplasty

  3. Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

    Energy Technology Data Exchange (ETDEWEB)

    Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

  4. Influence of interstitials elements (O, C, N) on the plastic behavior in tensile stress of polycrystalline niobium between -2530C and 8500C

    International Nuclear Information System (INIS)

    Fries, J.-F.

    1972-01-01

    The fundamental mechanism of plastic deformation of polycrystalline niobium was studied with 4 samples of different purity. At low temperatures (-253 0 C, +25 0 C) there is a linear relationship between the activation energy and the temperature for the four samples. The two models of Peierls-Nabarro and Escaig-Hirsh used are complementary. Ductile-brittle transition result of a competition between relaxation by fast propagation of a defect or by local plastic deformation. At intermediate temperatures (25 0 C - 850 0 C) on the contrary interstitial impurities play an important role in the plastic behavior of niobium. Mechanical characteristics temperature are modified by aging and can lead to a Portevin-Le Chatelier effect if dislocations are saturated by impurities [fr

  5. Investigating On Colour Stability Conditions Of Postirradiation Radiochromic Film Dosimeter

    International Nuclear Information System (INIS)

    Nguyen Nguyet Dieu; Doan Binh; Pham Thu Hong; Cao Van Chung; Nguyen Thanh Duoc

    2011-01-01

    B3 dosimeter is a thin film with average thickness of 0.0194 mm, which is supplied by the Gex company, the United States. This dosimeter was influenced by many factors: light, temperature, humidity during and after irradiation process. In fact, B3 film dosimeters will be stable under certain conditions such as tightly sealed packs, controlled irradiation and stored temperature after irradiated. Therefore, investigation of the stability effect of postirradiated B3 film dosimeters on the heating temperature, heating time and storing time is carried out before the absorbed dose is read and followed standard reading procedures. When exposed to ionizing radiation, the dosimeters change from colorless to colour. The absorbed doses are read on a Genesys 20 spectrophotometer at a wavelength of 544 nm. Absorbed dose range is investigated from 0.55 to 80 kGy. Experimental results were indicated that colour stability of the postirradiated dosimeters at a temperature of 65 ± 3 o C for 30 minutes and keeping them in desiccator for 5 minutes before read out. Under these conditions, colour stability of B3 film dosimeter has maintained for 3 months. (author)

  6. Status of automated tensile machine

    International Nuclear Information System (INIS)

    Satou, M.; Hamilton, M.L.; Sato, S.; Kohyama, A.

    1992-01-01

    The objective of this work is to develop the Monbusho Automated Tensile machine (MATRON) and install and operate it at the Pacific Northwest Laboratory (PNL). The machine is designed to provide rapid, automated testing of irradiated miniature tensile specimen in a vacuum at elevated temperatures. The MATRON was successfully developed and shipped to PNL for installation in a hot facility. The original installation plan was modified to simplify the current and subsequent installations, and the installation was completed. Detailed procedures governing the operation of the system were written. Testing on irradiated miniature tensile specimen should begin in the near future

  7. A simple method to identify radiation and annealing biases that lead to worst-case CMOS static RAM postirradiation response

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Dressendorfer, P.V.

    1987-01-01

    The authors illustrate a simple method to identify bias conditions that lead to worst-case postirradiation speed and timing response for SRAMs. Switching cell states between radiation and anneal should lead to maximum speed and timing degradation for many hardened designs and technologies. The greatest SRAM cell imbalance is also established by these radiation and annealing conditions for the hardened and commercial parts that we have examined. These results should provide insight into the behavior of SRAMs during and after irradiation. The results should also be useful to establishing guidelines for integrated-circuit functionality testing, and SEU and dose-rate upset testing, after total-dose irradiation

  8. Temper embrittlement, irradiation induced phosphorus segregation and implications for post-irradiation annealing of reactor pressure vessels

    International Nuclear Information System (INIS)

    McElroy, R.J.; English, C.A.; Foreman, A.J.; Gage, G.; Hyde, J.M.; Ray, P.H.N.; Vatter, I.A.

    1999-01-01

    Three steels designated JPB, JPC and JPG from the IAEA Phase 3 Programme containing two copper and phosphorus levels were pre- and post-irradiation Charpy and hardness tested in the as-received (AR), 1200 C/0.5h heat treated (HT) and heat treated and 450 C/2000h aged (HTA) conditions. The HT condition was designed to simulate coarse grained heat-affected zones (HAZ's) and showed a marked sensitivity to thermal ageing in all three alloys. Embrittlement after thermal ageing was greater in the higher phosphorus alloys JPB and JPG. Charpy shifts due to thermal ageing of between 118 and 209 C were observed and accompanied by pronounced intergranular fracture, due to phosphorus segregation. The irradiation embrittlement response was complex. The low copper alloys, JPC and JPB, in the HT and HTA condition exhibited significant irradiation induced Charpy shift but very low or even negative hardness changes indicating non-hardening embrittlement. The higher copper alloy, JPG, also exhibited irradiation hardening in line with its copper content. Fractographic and microchemical studies indicated irradiation induced phosphorus segregation and a transition from cleavage to intergranular failure at grain boundary phosphorus concentrations above a critical level. The enhanced grain boundary phosphorus level increased with dose in agreement with a kinetic segregation model developed at Harwell. The relevance of the thermal ageing studies to RPV Annealing for Plant-Life Extension was identified early in the program. It is of concern that annealing of RPV's has been performed, or is proposed, at temperatures in the range 425--475 C for periods of about 1 week (168h). Much attention has been given to the use of in-situ hardness measurements and machining miniature Charpy and tensile specimens from belt-line plate and weld materials. However, HAZ's, often containing higher phosphorus levels than the present materials, have largely been ignored. A post-irradiation annealing (PIA

  9. Postirradiation examination results for the irradiation effects scoping test 1

    International Nuclear Information System (INIS)

    Mehner, A.S.; Quapp, W.J.; Goetzmann, O.; Hobbins, R.R.

    1976-09-01

    A zircaloy-clad UO 2 fuel rod was operated above its critical heat flux within the in-pile test loop of the Power Burst Facility and later examined in the hot cells. The results of the postirradiation examinations are presented in this report. A Zr-UO 2 reaction at the fuel-cladding interface embrittled nearly as much of the cladding wall thickness as the Zr-water reaction on the exterior. Data on both the internal and external reactions, and cladding and fuel microstructures, are presented. Cladding embrittlement and rod failure are compared with several rod fragmentation criteria, and conclusions concerning fuel rod failure propagation in a power reactor system are made

  10. Statistical observations on postirradiation skin malignancies reported in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Michiharu; Ogata, Katsumi; Inoue, Shouhei (Miyazaki Medical Coll., Kiyotake (Japan))

    1989-01-01

    A review was made on 412 cases of postirradiation skin malignancies reported in Japan up to March 1988. The ratio of male to female was 2:1. Histologically, squamous cell carcinoma occupied 60% of all cases. The incidence of sarcoma has recently been increased. Sixty percent of all skin malignancies resulted from irradiation for benign diseases. Radiotherapy has recently become the treatment of choice for malignancy. The incidence of malignancy resulting from occupational exposure has remained unchanged. The latency period before the development of radiation-induced malignancy varied in the following order with cause or primary disease: occupation>benign tumors>malignant tumors; and it varied with histology in the following order: basal cell epithelioma>squamous cell carcinoma>sarcoma. Malignant tumors treated with large doses of high energy photon beams were likely to develop sarcomas in a relatively short latency period of time. (N.K.).

  11. Post-irradiation annealing of coarse-grained model alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ray, P H.N.; Wilson, C; McElroy, R J [AEA Reactor Services, Harwell (United Kingdom)

    1994-12-31

    Thermal ageing and irradiation studies have been carried out on three model alloys (JPC, JPB, JPG) that have identical compositions except for different levels of phosphorus and/or copper. They have been irradiated in three conditions, as-received, heat treated to produce a coarse grained microstructure (similar to heat-affected-zone), and in this condition further aged at 450 C to produce a temper embrittled condition. One of the alloy have been subject to a post-irradiation anneal. The effect of these treatments on mechanical property changes has been characterized by Charpy testing and Vickers hardness measurements; the phosphorus segregation has been studied by a combination of STEM and Auger techniques.

  12. Postirradiation effects in alanine dosimeter probes of two different suppliers

    International Nuclear Information System (INIS)

    Anton, Mathias

    2008-01-01

    The measurand relevant for the dosimetry for radiation therapy is the absorbed dose to water, D W . The Physikalisch-Technische Bundesanstalt (PTB) is establishing a secondary standard for D W for high-energy photon and electron radiation based on electron spin resonance (ESR) of the amino acid alanine. For practical applications, like, for example, intercomparison measurements using the ESR/alanine dosimetry system, the temporal evolution of the ESR signal of irradiated probes is an important issue. This postirradiation behaviour is investigated for alanine pellets of two different suppliers for different storage conditions. The influence of the storage conditions on the temporal evolution may be dependent on the type of probes used. The measurement and analysis method developed at the PTB is able to circumvent the apparent difficulties in the case of alanine/paraffin probes. Care has to be taken in case this method cannot be applied

  13. Postirradiation examination results for the irradiation effects scoping test 1

    International Nuclear Information System (INIS)

    Mehner, A.S.; Quapp, W.J.; Goetzmann, O.; Hobbins, R.R.

    1976-09-01

    A zircaloy-clad UO 2 fuel rod was operated above its critical heat flux within the in-pile test loop of the Power Burst Facility and later examined in the hot cells. The results of the postirradiation examinations are presented. A Zr-UO 2 reaction at the fuel-cladding interface embrittled nearly as much of the cladding wall thickness as the Zr-water reaction on the exterior. Data on both the internal and external reactions and the cladding and fuel microstructures are presented. Cladding embrittlement and rod failure are compared with several rod fragmentation criteria, and conclusions concerning fuel rod failure propagation in a power reactor system are made

  14. Postirradiation examination results for the irradiation effects scoping test 1

    Energy Technology Data Exchange (ETDEWEB)

    Mehner, A.S.; Quapp, W.J.; Goetzmann, O.; Hobbins, R.R.

    1976-09-01

    A zircaloy-clad UO/sub 2/ fuel rod was operated above its critical heat flux within the in-pile test loop of the Power Burst Facility and later examined in the hot cells. The results of the postirradiation examinations are presented in this report. A Zr-UO/sub 2/ reaction at the fuel-cladding interface embrittled nearly as much of the cladding wall thickness as the Zr-water reaction on the exterior. Data on both the internal and external reactions, and cladding and fuel microstructures, are presented. Cladding embrittlement and rod failure are compared with several rod fragmentation criteria, and conclusions concerning fuel rod failure propagation in a power reactor system are made.

  15. Using hardness to model yield and tensile strength

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.; Dogan, Omer N.; Schrems, Karol K.

    2005-02-01

    The current direction in hardness research is towards smaller and smaller loads as nano-scale materials are developed. There remains, however, a need to investigate the mechanical behavior of complex alloys for severe environment service. In many instances this entails casting large ingots and making numerous tensile samples as the bounds of the operating environment are explored. It is possible to gain an understanding of the tensile strength of these alloys using room and elevated temperature hardness in conjunction with selected tensile tests. The approach outlined here has its roots in the work done by Tabor for metals and low alloy and carbon steels. This research seeks to extend the work to elevated temperatures for multi-phase, complex alloys. A review of the approach will be given after which the experimental data will be examined. In particular, the yield stress and tensile strength will be compared to their corresponding hardness based values.

  16. Contribution to the pathophysiology of the postirradiation thrombocytopathy

    Energy Technology Data Exchange (ETDEWEB)

    Dienstbier, L; Pospisil, J; Zitko, M; Sadilkova, M; Polivkova, J [Karlova Univ., Prague (Czechoslovakia)

    1983-01-01

    Postirradiation damage of the thrombogenesis is one of the causes in developing a postirradiation hemorrhagic syndrome. In rats was demonstrated, that dependent on the dose of a total irradiation, a disturbance of the DNA replication on the level of developing megakaryocytes in the bone marrow, a derangement of the maturation process of the megakaryocytes and a delayed release of blood platelets into the peripheral blood were noted. The damage of the thrombopoiesis is not only the cause of numerical changes in peripheral thrombocyte counts, but also of their impaired function. In rabbits, after a total body irradiation with 5.0 Gy, a decrease of active thromboplastin independent on the decrease of blood platelets, was shown. The phospholipid metabolism of rabbit platelets an increased in vitro incorporation of /sup 32/P in phospholipids revealed after 4.0 Gy total body irradiation /sup 35/S in vitro incorporation demonstrated, that blood platelets released into the peripheral circulation on the 11th day after irradiation, are found in the moment of irradiation in the stage of promegakaryocytes. After total body irradiation, in thrombocyte functional tests a diminished retraction of the blood coagulum and a decreased production of malonylaldehyde were noted, but no significant changes in the adhesion and aggregation of thrombocytes after ADP and in PF/sub 3/-A and PF/sub 3/-F tests could be registered. Activity changes in thrombocytic lysosomal enzymes were observed in 8.0 Gy total body irradiated rats. During the period, when thrombocytes released from radiation damaged bone marrow were present in the peripheral blood, an activity increase of acid phosphatase and ..beta..-glucuronidase was demonstrated.

  17. Ab initio elastic properties and tensile strength of crystalline hydroxyapatite.

    Science.gov (United States)

    Ching, W Y; Rulis, Paul; Misra, A

    2009-10-01

    We report elastic constant calculation and a "theoretical" tensile experiment on stoichiometric hydroxyapatite (HAP) crystal using an ab initio technique. These results compare favorably with a variety of measured data. Theoretical tensile experiments are performed on the orthorhombic cell of HAP for both uniaxial and biaxial loading. The results show considerable anisotropy in the stress-strain behavior. It is shown that the failure behavior of the perfect HAP crystal is brittle for tension along the z-axis with a maximum stress of 9.6 GPa at 10% strain. Biaxial failure envelopes from six "theoretical" loading tests show a highly anisotropic pattern. Structural analysis of the crystal under various stages of tensile strain reveals that the deformation behavior manifests itself mainly in the rotation of the PO(4) tetrahedron with concomitant movements of both the columnar and axial Ca ions. These results are discussed in the context of mechanical properties of bioceramic composites relevant to mineralized tissues.

  18. Structural changes in mammalian cell DNA induced by low-dose x-ray damage and subsequent postirradiation incubation in the presence and absence of caffeine

    International Nuclear Information System (INIS)

    Wun, K.L.W.; Shafer, R.H.

    1982-01-01

    DNA damage and postirradiation incubation effects from X-ray doses of 30-2000 rad delivered to rat 9L cells in vitro were detemined by viscoelastic analysis of neutral (pH 7) cell lysates. Damage studies showed first an increase in the principal viscoelastic retardation time, T, with increasing dose, followed by a decrease, with the maximum retardation time occurring at 1000 rad. Also, the variation of retardation time with increasing postirradiation incubation time at 37 0 C was determined. At doses greater than 50 rad, this variation was quite complicated; e.g., following 100 rad, the retardation time showed a minimum followed by a maximum as a function of incubation time. All doses showed an initial return of T to close to control values at early times. Following 50 rad, control viscoelastic behavior was recovered in 1 hr. For doses of 100 rad and higher, 5 hr or more were required for complete return to control behavior has determined by both the value of T and the viscoelastic response to a probe dose of 200 rad immediately prior to lysis. These results are analyzed in terms of the dependence of the principal retardation time T on DNA molecular weight and conformation. Evidence is discussed indicating that the observed changes in T during postirradiation incubation reflect repair of DNA damage. Postirradiation incubation in the presence of 0.5 mM caffeine appeared to result in an inhibition of repair. In this case, both 30- and 50-rad doses required 5 hr for complete recovery of control behavior and showed the minimum and maximum in the T vs incubation time curve observed for incubation in the absence of caffeine following a dose of 100 rad

  19. The tensile strength of mechanical joint prototype of lontar fiber composite

    Science.gov (United States)

    Bale, Jefri; Adoe, Dominggus G. H.; Boimau, Kristomus; Sakera, Thomas

    2018-03-01

    In the present study, an experimental activity has been programmed to investigate the effect of joint prototype configuration on tensile strength of lontar (Borassus Flabellifer) fiber composite. To do so, a series of tests were conducted to establish the tensile strength of different joint prototype configuration specimen of lontar fiber composite. In addition, post observation of macroscope was used to map damage behavior. The analysis of lontar fiber composite is a challenge since the material has limited information than others natural fiber composites materials. The results shown that, under static tensile loading, the tensile strength of 13 MPa produced by single lap joint of lontar fiber composite is highest compare to 11 MPa of tensile strength generated by step lap joint and double lap joint where produced the lowest tensile strength of 6 MPa. It is concluded that the differences of tensile strength depend on the geometric dimensions of the cross-sectional area and stress distribution of each joint prototype configuration.

  20. Tensile properties of vanadium alloys irradiated at 390{degrees}C in EBR-II

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Tsai, H.C.; Nowicki, L.J. [Argonne National Lab., IL (United States)] [and others

    1997-08-01

    Vanadium alloys were irradiated in Li-bonded stainless steel capsules to {approx}390{degrees}C in the EBR-II X-530 experiment. This report presents results of postirradiation tests of tensile properties of two large-scale (100 and 500 kg) heats of V-4Cr-Ti and laboratory (15-30 kg) heats of boron-doped V-4Cr-4Ti, V-8Cr-6Ti, V-5Ti, and V-3Ti-1Si alloys. Tensile specimens, divided into two groups, were irradiated in two different capsules under nominally similar conditions. The 500-kg heat (No. 832665) and the 100-kg heat (VX-8) of V-4Cr-4Ti irradiated in one of the subcapsules exhibited complete loss of work-hardening capability, which was manifested by very low uniform plastic strain. In contrast, the 100-kg heat of V-4Cr-4Ti irradiated in another subcapsule exhibited good tensile properties (uniform plastic strain 2.8-4.0%). A laboratory heat of V-3Ti-1Si irradiated in the latter subcapsule also exhibited good tensile properties. These results indicate that work-hardening capability at low irradiation temperatures varies significantly from heat to heat and is influenced by nominally small differences in irradiation conditions.

  1. An automated tensile machine for small specimens heavily neutron irradiated in FFTF/MOTA

    International Nuclear Information System (INIS)

    Kohyama, Akira; Sato, Shinji; Hamada, Kenichi

    1993-01-01

    The objective of this work is to develop a fully automated tensile machine for post-irradiation examination (PIE) of Fast Flux Test Facility (FFTF)/Materials Open Test Assembly (MOTA) irradiated miniature tension specimens. The anticipated merit of the automated tensile machine is to reduce damage to specimens during specimen handling for PIE and to reduce exposure to radioactive specimens. This machine is designed for testing at elevated temperatures, up to 873 K, in a vacuum or in an inert gas environment. Twelve specimen assemblies are placed in the vacuum chamber that can be tested successively in a fully automated manner. A unique automated tensile machine for the PIE of FFTF/MOTA irradiated specimens, the Monbusho Automated Tensile Machine (MATRON) consists of a test frame with controlling units and an automated specimen-loading apparatus. The qualification of the test frame has been completed, and the results have satisfied the machine specifications. The capabilities of producing creep and relaxation data have been demonstrated for Cu, Al, 316SS, and ferritic steels. The specimen holders for the three-point bending test and the small bulge test (small punch test; SP test) were also designed and produced

  2. Size and temperature dependence of the tensile mechanical properties of zinc blende CdSe nanowires

    International Nuclear Information System (INIS)

    Fu, Bing; Chen, Na; Xie, Yiqun; Ye, Xiang; Gu, Xiao

    2013-01-01

    The effect of size and temperature on the tensile mechanical properties of zinc blende CdSe nanowires is investigated by all atoms molecular dynamic simulation. We found the ultimate tensile strength and Young's modulus will decrease as the temperature and size of the nanowire increase. The size and temperature dependence are mainly attributed to surface effect and thermally elongation effect. High reversibility of tensile behavior will make zinc blende CdSe nanowires suitable for building efficient nanodevices.

  3. Design of a decontamination section of the post-irradiation examination laboratory

    International Nuclear Information System (INIS)

    Homberger, Victor; Coronel, Ruben R.; Laumann, Victor; Perez, Jorge O.; Quinteros, Andrea N.; Ratner, Marcos

    1999-01-01

    The Post-Irradiation Examination Laboratory activities include the decontamination of expensive equipment of different sizes and weight, involving the complexity and extension of the necessary decontamination. A decontamination section has been designed for that purpose. (author)

  4. Limits of radiobiology in conventional postirradiation of breast cancer

    International Nuclear Information System (INIS)

    Wall, H. van der

    1982-01-01

    The conventional postirradiation of breast cancer including radiation pneumonitis in relation to age and irradiation method, are discussed. The risk of radiation pneumonitis is with a single surface dose of 65 mC/kg higher than with 52 mC/kg. The dose at the chest wall is for the development of a radiation pneumonitis of lower importance than the dose at the supra- and intraclavicular field. At both these fields intersections of the cones of radiation in the lungs, which could cause dose peaks not possible to evaluate, must be taken into consideration. At the reported and wanted tumor dose of 1032 mC/kg at the deferent axillary lymph tracts a more indulgent method with a single dose of 65 mC/kg and with a prolongation by 3 series a pneumonitis could not be avoided in 30% of the irradiated women. Because of the harmless process one could answer for the risk of a radiation pneumonitis, if other therapeutic possibilities are not available. The age of the patients is not a special risk as to radiation pneumonitis. (author)

  5. Limits of radiobiology in conventional postirradiation of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    van der Wall, H [Bezirkskrankenhaus Schwerin (German Democratic Republic)

    1982-08-01

    The conventional postirradiation of breast cancer including radiation pneumonitis in relation to age and irradiation method, are discussed. The risk of radiation pneumonitis is with a single surface dose of 65 mC/kg higher than with 52 mC/kg. The dose at the chest wall is for the development of a radiation pneumonitis of lower importance than the dose at the supra- and intraclavicular field. At both these fields intersections of the cones of radiation in the lungs, which could cause dose peaks not possible to evaluate, must be taken into consideration. At the reported and wanted tumor dose of 1032 mC/kg at the deferent axillary lymph tracts a more indulgent method with a single dose of 65 mC/kg and with a prolongation by 3 series a pneumonitis could not be avoided in 30% of the irradiated women. Because of the harmless process one could answer for the risk of a radiation pneumonitis, if other therapeutic possibilities are not available. The age of the patients is not a special risk as to radiation pneumonitis.

  6. The mechanisms of inhibition of the postirradiation recovery in cells

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.; Semenova, E.G.; Volkova, Z.M.

    1974-01-01

    A study was made of the effect of acriflavine (in a concentration of 5x10 -5 -5x10 -7 M) and caffeine (in a concentration of 1x10 -2 and 1x10 -3 M) on the inclusion of labelled thymidine in nuclei of HeLa Zh-63 cells following UV-irradiation. Caffeine clearly reduces the survival of the irradiated cells and suppresses the irregular DNA synthesis in the cells which is induced by UV-irradiation, in both asynchronous culture and culture synchronized at the G 1 stage, for 7 hours following irradiation. Acriflavine (5x10 -7 M) does not affect the post-irradiation survival rate of the cells and suppresses irregular DNA synthesis in asynchronous culture at all concentrations tested. In contrast with caffeine, acriflavine (5x10 -6 M) suppresses irregular DNA synthesis in culture sychronized at the G 1 stage for only the first 2 hours following irradiation. Acriflavine suppresses replicate DNA synthesis in the irradiated cells, whereas caffeine does not affect this process. (author)

  7. Postirradiation thermocyclic loading of ferritic-martensitic structural materials

    Science.gov (United States)

    Belyaeva, L.; Orychtchenko, A.; Petersen, C.; Rybin, V.

    Thermonuclear fusion reactors of the Tokamak-type will be unique power engineering plants to operate in thermocyclic mode only. Ferritic-martensitic stainless steels are prime candidate structural materials for test blankets of the ITER fusion reactor. Beyond the radiation damage, thermomechanical cyclic loading is considered as the most detrimental lifetime limiting phenomenon for the above structure. With a Russian and a German facility for thermal fatigue testing of neutron irradiated materials a cooperation has been undertaken. Ampule devices to irradiate specimens for postirradiation thermal fatigue tests have been developed by the Russian partner. The irradiation of these ampule devices loaded with specimens of ferritic-martensitic steels, like the European MANET-II, the Russian 05K12N2M and the Japanese Low Activation Material F82H-mod, in a WWR-M-type reactor just started. A description of the irradiation facility, the qualification of the ampule device and the modification of the German thermal fatigue facility will be presented.

  8. Postirradiation examination of high-density uranium alloy dispersion fuels

    International Nuclear Information System (INIS)

    Hayes, S.L.; Meyer, M.K.; Hofman, G.L.; Strain, R.V.

    1998-01-01

    Two irradiation test vehicles, designated RERTR-2, were inserted into the Advanced Test reactor in Idaho in August 1997. These tests were designed to obtain irradiation performance information on a variety of potential new, high-density uranium alloy dispersion fuels, including U-10Mo, U-8Mo, U-6Mo, U-4Mo, U-9Nb-3Zr, U-6Nb-4Zr, U-5Nb-3Zr, U-6Mo-1Pt, U-6Mo-0.6Ru and U-10Mo-0.05Sn: the intermetallic compounds U 2 Mo and U-10Mo-0.-5Sn; the intermetallic compounds U 2 Mo and U 3 Si 2 were also included in the fuel test matrix. These fuels are included in the experiments as microplates (76 mm x 22 mm x 1.3mm outer dimensions) with a nominal fuel volume loading of 25% and irradiated at relatively low temperature (∼100 deg C). RERTR-1 and RERTR-2 were discharged from the reactor in November 1997 and July 1998, respectively at calculated peak fuel burnups of 45 and 71 at %-U 235 Both experiments are currently under examination at the Alpha Gamma Hot Cell Facility at Argonne National Laboratory in Chicago. This paper presents the postirradiation examination results available to date from these experiments. (author)

  9. Post-irradiation hyperamylasemia as a biological dosimeter

    International Nuclear Information System (INIS)

    Dubray, Bernard; Girinski, Theo; Hennequin, Christophe; Socie, Gerard; Bonnay, Marc; Cosset, J.M.; Thames, H.D.; Becciolini, Aldo; Porciani, Sauro

    1992-01-01

    Serum alpha-amylasemia was measured before and 24 h after either total body (31 patients) or localized irradiation including salivary glands (40 patients) or pancreatic area (22 patients). A significant increase in amylasemia was observed for doses to the parotid glands larger than 0.5Gy. A sigmoid function of dose was fitted to the data and predicted a maximum amylasemia level for doses larger than 4Gy and smaller than 10Gy. Raw data from other published series were adequately described by the same model. However, confidence limits of parameters remained wide, because of a considerable interindividual variability. Post-irradiation hyperamylasemia appears to provide good criteria for triage of accidentally irradiated patients: 24 h after a dose larger than 2Gy to the parotid glands, 91% of patients had an amylasemia level higher than 2.5-fold the upper normal value (sensitivity). Conversely, 96% had their serum amylasemia lower than 2.5-fold the upper normal value when dose was smaller than 2Gy (specificity). However, a retrospective estimation of the absorbed dose (dosimetry) is not likely to be very precise because of the large interindividual variability. (author). 21 ref.; 1 fig.; 3 tabs

  10. Effect of postirradiation anoxia on radiosensitivity of lymphocytes

    International Nuclear Information System (INIS)

    Schrek, R.

    1976-01-01

    Radiosensitivity was measured by viable-lymphocyte counts and by uridine uptake. The viability of the lymphocytes was based on morphologic characteristics visualized by phase contrast microscopy of the cells in a special slide chamber. Low doses of x rays (10 to 1000 R) and incubation at 37 0 C killed lymphocytes in interphase with the production of pyknotic nuclei (nuclear death), and large doses (6000 R) produced nuclei with clear nucleoplasm (cytoplasmic death). Nuclear, but not cytoplasmic, death was inhibited by incubation of the irradiated cells at 27 0 C. Postirradiation anoxia had no effect on development of the nuclear and cytoplasmic death of lymphocytes irradiated with 100 to 6000 R. Anoxia had no effect on the early response of lymphocytes to phytohemagglutinin (PHA) [increase in ribonucleic acid (RNA) and protein synthesis] but inhibited completely the late effects [increase in deoxyribonucleic acid (DNA) synthesis and transformation into lymphoblastoid cells]. The PHA caused relative radioresistance of lymphocytes under aerobic conditions and, to a lesser extent, under anaerobic conditions. The slight radioresistance induced by PHA in anoxic lymphocytes apparently did not depend on an increase in DNA synthesis or on the transformation to lymphoblastoid cells

  11. Postirradiation properties of a UV-sensitive variant of CHO

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.D.; de Veciana, M.; Presson-Tincknell, B. (California Univ., Berkeley (USA). Lawrence Berkeley Lab.)

    1982-08-01

    A UV-hypersensitive mutant of Chinese hamster ovary (CHO) cells, termed 43-3B, has been used in a comparative study with the wild type CHO in order to determine the involvement of repair in several postirradiation phenomena. 43-3B has the same growth rate and chromosome number as the wild type CHO-9. It is hypersensitive to UV irradiation. 43-3B shows only about 17% of the UV-stimulated unscheduled DNA repair synthesis of CHO-9 as measured by autoradiography. When breaks in supercoiled chromatin are measured after UV by the nucleoid sedimentation method, the mutant appears to be capable of carrying out only limited incision. A much reduced ability to recover control rates of semiconservative DNA synthesis after UV irradiation was observed in the repair-deficient 43-3B cell line, suggesting that the removal of UV-induced replication blocks by excision repair is the most important factor in allowing recovery of UV-inhibited DNA synthesis. Recovery of colony-forming ability between fractionated UV exposures was observed in the wild type CHO-9, but little recovery was seen in 43-3B. This indicates that excision repair capability can also be important in split-fluence recovery.

  12. Proteomics of post-irradiation recovery in D. radiodurans

    International Nuclear Information System (INIS)

    Basu, Bhakti; Apte, Shree Kumar

    2012-01-01

    An extremophile Deinococcus radiodurans is bestowed with an extraordinary DNA repair ability that renders it virtually resistant to all known forms of DNA damage caused by ionizing radiations (10 kGy of gamma rays), UV (1 kJ/m 2 ) or weeks of desiccation etc. The genome of D. radiodurans encodes a unique combination of DNA repair pathways such as prokaryotic type RecFOR mediated homologous recombination (HR) and nucleotide/base excision repair along with eukaryotic type strand annealing (SA) and non-homologous end joining (NHEJ), but is devoid of universal prokaryotic DNA repair pathways such as RecBCD mediated HR, photo-reactivation and SOS response. Collective evidence obtained so far from multiple approaches, have indicated (i) that all genes essential for DNA repair are not necessarily induced following radiation stress (ii) early RecA independent DNA assembly occurs, and (iii) absolute necessity of RecA dependent HR for final genome restitution. The 6 kGy gamma irradiation inducible proteome dynamics were mapped during the post-irradiation growth arrest phase by 2D protein electrophoresis coupled with mass spectrometry. Radiation inducible expression of at least 33 proteins was evident in the first 1h of post irradiation recovery

  13. Post-irradiation examinations of THERMHET composite fuels for transmutation

    Science.gov (United States)

    Noirot, J.; Desgranges, L.; Chauvin, N.; Georgenthum, V.

    2003-07-01

    The thermal behaviour of composite targets dedicated to minor actinide transmutation was studied using THERMHET (thermal behaviour of heterogeneous fuel) irradiation in the SILOE reactor. Three inert matrix fuel designs were tested (macro-mass, jingle and microdispersion) all with a MgAl 2O 4 spinel inert matrix and around 40% weight of UO 2 to simulate minor actinide inclusions. The post-irradiation examinations led to a new interpretation of the temperature measurement by thermocouples located in the central hole of the pellets. A major change in the micro-dispersed structure was detected. The examinations enabled us to understand the behaviour of the spinel during the different stages of irradiation. They revealed an amorphisation at low temperature and then a nano re-crystallisation at high temperature of the spinel in the micro-dispersed case. These results, together with those obtained in the MATINA irradiation of an equivalent structure, show the importance of the irradiation temperature on spinel behaviour.

  14. Post-irradiation examinations of THERMHET composite fuels for transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Noirot, J. E-mail: jnoirot@cea.fr; Desgranges, L.; Chauvin, N.; Georgenthum, V

    2003-07-01

    The thermal behaviour of composite targets dedicated to minor actinide transmutation was studied using THERMHET (thermal behaviour of heterogeneous fuel) irradiation in the SILOE reactor. Three inert matrix fuel designs were tested (macro-mass, jingle and microdispersion) all with a MgAl{sub 2}O{sub 4} spinel inert matrix and around 40% weight of UO{sub 2} to simulate minor actinide inclusions. The post-irradiation examinations led to a new interpretation of the temperature measurement by thermocouples located in the central hole of the pellets. A major change in the micro-dispersed structure was detected. The examinations enabled us to understand the behaviour of the spinel during the different stages of irradiation. They revealed an amorphisation at low temperature and then a nano re-crystallisation at high temperature of the spinel in the micro-dispersed case. These results, together with those obtained in the MATINA irradiation of an equivalent structure, show the importance of the irradiation temperature on spinel behaviour.

  15. Post-irradiation examinations of THERMHET composite fuels for transmutation

    International Nuclear Information System (INIS)

    Noirot, J.; Desgranges, L.; Chauvin, N.; Georgenthum, V.

    2003-01-01

    The thermal behaviour of composite targets dedicated to minor actinide transmutation was studied using THERMHET (thermal behaviour of heterogeneous fuel) irradiation in the SILOE reactor. Three inert matrix fuel designs were tested (macro-mass, jingle and microdispersion) all with a MgAl 2 O 4 spinel inert matrix and around 40% weight of UO 2 to simulate minor actinide inclusions. The post-irradiation examinations led to a new interpretation of the temperature measurement by thermocouples located in the central hole of the pellets. A major change in the micro-dispersed structure was detected. The examinations enabled us to understand the behaviour of the spinel during the different stages of irradiation. They revealed an amorphisation at low temperature and then a nano re-crystallisation at high temperature of the spinel in the micro-dispersed case. These results, together with those obtained in the MATINA irradiation of an equivalent structure, show the importance of the irradiation temperature on spinel behaviour

  16. Post-irradiation examination of overheated fuel bundles

    International Nuclear Information System (INIS)

    Sears, D.F.; Primeau, M.F.; Leach, D.A.

    1995-01-01

    Post-irradiation examinations (PIE) were conducted on prototype 43-element CANDU fuel bundles that overheated during test irradiations in the NRU reactor. PIE revealed that the bundles remained physically intact, but on several elements the Zr-4 sheath collapsed into axial gaps between the pellet stack and end caps, between adjacent pellets within the stacks, and into missing pellet chips and cracks. Helium pressurization tests showed that none of the collapsed elements leaked. Hydride blisters were discovered on a few elements, but the source of the hydrogen was not linked to a breach of the cladding or end caps. These defects were attributed to primary hydriding. Microstructural changes in the fuel and cladding indicate that the cladding-was briefly exposed to temperatures in the range 600-800 o C and pressures above 11.2 MPa. The results show that Zr-4 cladding behaves in a highly ductile manner during such transient, high-temperature and high-pressure excursions. (author)

  17. Post-irradiation examination of overheated fuel bundles

    International Nuclear Information System (INIS)

    Sears, D.F.; Primeau, M.F.; Leach, D.A.

    1997-08-01

    Post-irradiation examinations (PIE) were conducted on prototype 43-element CANDU fuel bundles that overheated during test irradiations in the NRU reactor. PIE revealed that the bundles remained physically intact, but on several elements the Zr-4 sheath collapsed into axial gaps between the pellet stack and end caps, between adjacent pellets within the stacks, and into missing pellet chips and cracks. Helium pressurization tests showed that none of the collapsed elements leaked. Hydride blisters were discovered on a few elements, but the source of the hydrogen was.not linked to a breach of the cladding or end caps. These defects were attributed to primary hydriding. Microstructural changes in the fuel and cladding indicate that the cladding was briefly exposed to temperatures in the range 600-800 o C and pressures above 11.2MPa. The results show that Zr-4 cladding behaves in a highly ductile manner during such transient, high-temperature and high-pressure excursions. (author)

  18. The operation of post-irradiation examination facility

    International Nuclear Information System (INIS)

    Kim, Eun Ka; Min, Duk Ki; Lee, Young Kil

    1994-12-01

    The operation of post-irradiation examination facility was performed as follow. HVAC and pool water treatment system were continuously operated, and radiation monitoring in PIE facility has been carried out to maintain the facility safely. Inspection of the fuel assembly (F02) transported from Kori Unit 1 was performed in pool, and fuel rods extracted from the fuel assembly (J44) of Kori Unit 2 NPP were examined in hot cell. A part of deteriorated pipe line of drinking water was exchanged for stainless steel pipe to prevent leaking accidents. Halon gas system was also installed in the exhausting blower room for fire fighting. And IAEA inspection camera for safeguard of nuclear materials was fixed at the wall in pool area. Radiation monitoring system were improved to display the area radioactive value at CRT monitor in health physics control room. And automatic check system for battery and emergency diesel generator was developed to measure the voltage and current of them. The performance test of oxide thickness measuring device installed in hot cell for irradiated fuel rod and improvement of the device were performed, and good measuring results using standard sample were obtained. The safeguard inspection of nuclear materials and operation inspection of the facility were carried out through the annual operation inspection, quarterly IAEA inspection and quality assurance auditing. 26 tabs., 43 figs., 14 refs. (Author) .new

  19. Swelling Characteristics and Tensile Properties of Natural Fiber ...

    African Journals Online (AJOL)

    The swelling behavior and tensile strength of natural fiber-reinforced plastic in premium motor spirit (PMS), dual purpose kerosene (DPK) and sea water have been studied. Composite formed by reinforcing polyester resin with Okam fibers was immersed in the selected solvents for 16 weeks (4 months). Swelling ...

  20. EXPERIMENTAL INVESTIGATION ON TENSILE STRENGTH OF JACQUARD KNITTED FABRICS

    Directory of Open Access Journals (Sweden)

    BRAD Raluca

    2015-05-01

    Full Text Available An objective approach to select the best fabric for technical and home textiles consists in mechanical properties evaluation. The goal of this study is to analyze the behavior of knitted fabrics undergoing stretch stress. In this respect, three types of 2 colors Rib structure (backstripes jacquard, twillback jacquard and double-layered 3x3 rib fabric have been presented and tested for tensile strength and elongation on three directions. First, the elasticity and the behavior of knitted Rib fabrics were described The fabrics were knitted using 100% PAN yarns with Nm 1/15x2 on a E5 CMS 330 Stoll V-bed knitting machine, and have been tested using INSTROM 5587 Tensile Testing Machine in respect of standards conditions. After a relaxation period, 15 specimens were prepared, being disposed at 0°, 45 and 90 angles to the wale direction on the flat knitted panel. The tensile strength and the elongation values were recorded and mean values were computed. After strength and tensile elongation testing for 3 types of rib based knitted fabrics, one can see that the double layer knit presents the best mechanical behavior, followed by birds-eyebacking 2 colors Jacquard and then back striped Jacquard. For tensile stress in bias direction, the twillbacking Jacquard has a good breakage resistance value due to the higher number of rib sinker loops in structure that are positioned on the same direction with the tensile force. The twillbacking Jacquard structure could be considered as an alternative for the base material for decorative and home textile products.

  1. Power-Cooling-Mismatch Test Series. Test PCM-2: postirradiation examination

    International Nuclear Information System (INIS)

    Seiffert, S.L.

    1977-03-01

    The report describes the results of the postirradiation examination of four 0.91-m long pressurized water reactor (PWR) type, UO 2 -fueled zircaloy-clad fuel rods tested in an in-pile experimental investigation of pre- and post-departure from nucleate boiling (DNB) behavior of previously unirradiated fuel rods. None of the four fuel rods tested failed during testing or during reactor shut down. Visual and metallographic examination of the individual fuel rods indicated that the length of the high temperature zone of film boiling varied from rod to rod. Two of the four fuel rods showed evidence of damage by film boiling, characterized by oxide spalling and cladding collapse. Metallographic examination of these fuel rods showed internal cladding oxidation resulting from fuel-cladding reaction. Cladding embrittlement by oxidation is evaluated. A comparison of the cladding surface temperatures estimated metallographically for the separate fuel rods with cladding surface temperatures measured during testing and calculated from the Fuel Rod Analysis Program-Transient (FRAP-T) computer code is included

  2. Damage-induced tensile instability

    International Nuclear Information System (INIS)

    Hult, J.

    1975-01-01

    The paper presents a unified description of ductile and brittle rupture phenomena in structural components under tensile loading with particular emphasis on creep rupture. Two structural elements are analyzed in detail: 1) the uniform tensile bar subject to a Heaviside history of tensile force and superimposed such loadings, i.e. staircase histories, and 2) the thinwalled spherical pressure vessel subject to a Heaviside history of internal pressure. For both these structures the conditions for instantaneous as well as delayed rupture are analysed. It is shown that a state of mechanical instability will be reached at a certain load or after a certain time. The cases of purely ductile rupture and purely brittle fracture are identified as two limiting cases of this general instability phenomenon. The Kachanov-Rabotnov damage law implies that a structural component will fail in tension only when it has reached a state of complete damage, i.e. zero load carrying capacity. The extended law predicts failure at an earlier stage of the deterioration process and is therefore more compatible with experimental observation. Further experimental support is offered by predictions for staircase loading histories, both step-up and step-down type. The presented damage theory here predicts strain histories which are in closer agreement with test data than predictions based on other phenomenological theories

  3. Possible association of mucous blanket integrity with postirradiation colonization resistance

    International Nuclear Information System (INIS)

    Walker, R.I.; Brook, I.; Costerton, J.W.; MacVittie, T.; Myhal, M.L.

    1985-01-01

    Radiation-induced infections can be associated with changes in colonization potential of the intestine. Since the mucous blanket, which overlays the epithelium, is a major mucosal structure and is heavily colonized by microorganisms, we examined the status of the mucus after radiation and evaluated susceptibility to intestinal challenge with bacteria. A downward shift (2.5 X 10(8) cells/g to 5.3 X 10(5)) of total facultatively anaerobic bacteria of the ileum of C3HeB/FeJ mice was detected by 3 days post exposure to 10 Gy 60Co. Numbers of flora returned to normal by 11 days after radiation. Scanning electron microscopy was used to show that the loss of bacteria could be associated with major disruptions of the continuity of the mucous blanket. The pathogen Pseudomonas aeruginosa adhered to mouse mucous films used in in vitro assays. When irradiated mice were challenged orally with 1 X 10(5) P. aeruginosa on days 1, 2, or 3 after irradiation, a progressive increase in susceptibility was seen, but no animals died before Day 4 postirradiation. Sensitivity to subcutaneous (sc) challenge with Pseudomonas also increased by Day 3 and was probably due largely to the profound neutropenia observed. Immunoglobulin G (Gamimmune), which protected burned mice infected with Pseudomonas, was ineffectual in treatment of 7 or 10 Gy irradiated mice challenged either orally or sc with the organism. The ileal mucosal barrier was compromised after radiation in ways which could facilitate epithelial colonization, an event which combined with other immunological and physiological decrements in this model can compromise the effectiveness of therapeutic modalities

  4. Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

    Science.gov (United States)

    Heard, W.; Song, B.; Williams, B.; Martin, B.; Sparks, P.; Nie, X.

    2018-01-01

    This review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior of geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Uniqueness and limitations for each experimental technique are also discussed.

  5. Post-irradiation creep properties of four plates and two forgings DIN 1.4948 steel from the SNR-300 permanent primary structures

    International Nuclear Information System (INIS)

    Schaaf, B. van der.

    1987-01-01

    The safety authorities, involved in the licensing procedure of the SNR-300, have required the determination of the irradiation effect on the heat-to-heat variation of tensile and creep properties of Werkst. No. DIN 1.4948 austenitic stainless steel. These data are lacking in the present codes and they are necessary for the design and safety considerations of the permanent structures. Results are presented of about 200 tests on irradiated and unirradiated material of 6 heats used in the production of the SNR-300 permanent structures. After irradiation in the HFR-Petten to neutron fluences relevant for the SNR-300 service conditions post-irradiation tensile and creep tests (up to 10,000 hrs rupture time) were performed in the temperature range 723 K to 923 K. All heats are embrittled by irradiation resulting in reduction of rupture times, creep strength and ultimate tensile strength. The considerable reduction is attributed to helium enhanced intergranular creep crack growth, which reduces the ductility and strength, but does not affect the creep rate. The variation of tensile and creep properties is large and independent of irradiation. The minimum derived creep strength in irradiated condition drops below the values expected in the ASME Code and VdTuV Blatt. In design and safety analyses the irradiation effect on creep properties must be accounted for with an appropriate reduction factor. The predictions given, have to be verified with long-term creep tests and parts of the SNR surveillance programme. 172 figs.; 17 refs.; 58 tables

  6. Microstructural evolution during tensile deformation of polypropylenes

    International Nuclear Information System (INIS)

    Dasari, A.; Rohrmann, J.; Misra, R.D.K.

    2003-01-01

    Tensile deformation processes occurring at varying strain rates in high and low crystallinity polypropylenes and ethylene-propylene di-block copolymers have been investigated by scanning electron microscopy. This is examined for both long and short chain polymeric materials. The deformation processes in different polymeric materials show striking dissimilarities in spite of the common propylene matrix. Additionally, the deformation behavior of long and their respective short chain polymers was different. Deformation mechanisms include crazing/tearing, wedging, ductile ploughing, fibrillation, and brittle fracture. The different modes of deformation are depicted in the form of strain rate-strain diagrams. At a constant strain rate, the strain to fracture follows the sequence: high crystallinity polypropylenes< low crystallinity polypropylenes< ethylene-propylene di-block copolymers, indicative of the trend in resistance to plastic deformation

  7. Postirradiation examination of a low enriched U3Si2-Al fuel element manufactured and irradiated at Batan, Indonesia

    International Nuclear Information System (INIS)

    Suripto, A.; Sugondo, S.; Nasution, H.

    1994-01-01

    The first low-enriched U 3 Si 2 -Al dispersion plate-type fuel element produced at the Nuclear Fuel Element Center, BATAN, Indonesia, was irradiated to a peak 235 U burnup of 62%. Postirradiation examinations performed to data shows the irradiation behavior of this element to be similar to that of U 3 Si 2 -Al plate-type fuel produced and tested at other institutions. The main effect of irradiation on the fuel plates is a thickness increase of 30--40 μm (2.5-3.0%). This thickness increase is almost entirely due to the formation of a corrosion layer (Boehmite). The contribution of fuel swelling to the thickness increase is rather small (less than 10 μm) commensurate with the burnup of the fuel and the relatively moderate as-fabricated fuel volume fraction of 27% in the fuel meat

  8. Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

    International Nuclear Information System (INIS)

    Singh, B.N.; Xiaoxu Huang; Taehtinen, S.; Moilamen, P.; Jacquet, P.; Dekeyser, J.

    2007-11-01

    Traditionally, the effect of irradiation on mechanical properties of metals and alloys is determined using post-irradiation tests carried out on pre-irradiated specimens and in the absence of irradiation environment. The results of these tests may not be representative of deformation behaviour of materials used in the structural components of a fission or fusion reactor where the materials will be exposed concurrently to displacement damage and external and/or internal stresses. In an effort to evaluate and understand the dynamic response of materials under these conditions, we have recently performed a series of uniaxial tensile tests on Fe-Cr and pure iron specimens in the BR-2 reactor at Mol (Belgium). The present report first provides a brief description of the test facilities and the procedure used for performing the in-reactor tests. The results on the mechanical response of materials during these tests are presented in the form of stress-displacement dose and the conventional stress-strain curves. For comparison, the results of post-irradiation tests and tests carried out on unirradiated specimens are also presented. Results of microstructural investigations on the unirradiated and deformed, irradiated and undeformed, post-irradiation deformed and the in-reactor deformed specimens are also described. During the in-reactor tests the specimens of both Fe-Cr alloy and pure iron deform in a homogeneous manner and do not exhibit the phenomenon of yield drop. An increase in the pre-yield dose increases the yield stress but not the level of maximum flow stress during the in-reactor deformation of Fe-Cr alloy. Neither the in-reactor nor the post-irradiation deformed specimens of Fe-Cr alloy and pure iron showed any evidence of cleared channel formation. Both in Fe-Cr and pure iron, the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post-irradiation

  9. Ratcheting Strain and Microstructure Evolution of AZ31B Magnesium Alloy under a Tensile-Tensile Cyclic Loading.

    Science.gov (United States)

    Yan, Zhifeng; Wang, Denghui; Wang, Wenxian; Zhou, Jun; He, Xiuli; Dong, Peng; Zhang, Hongxia; Sun, Liyong

    2018-03-28

    In this paper, studies were conducted to investigate the deformation behavior and microstructure change in a hot-rolled AZ31B magnesium alloy during a tensile-tensile cyclic loading. The relationship between ratcheting effect and microstructure change was discussed. The ratcheting effect in the material during current tensile-tensile fatigue loading exceeds the material's fatigue limit and the development of ratcheting strain in the material experienced three stages: initial sharp increase stage (Stage I); steady stage (Stage II); and final abrupt increase stage (Stage III). Microstructure changes in Stage I and Stage II are mainly caused by activation of basal slip system. The Extra Geometrically Necessary Dislocations (GNDs) were also calculated to discuss the relationship between the dislocation caused by the basal slip system and the ratcheting strain during the cyclic loading. In Stage III, both the basal slip and the {11-20} twins are found active during the crack propagation. The fatigue crack initiation in the AZ31B magnesium alloy is found due to the basal slip and the {11-20} tensile twins.

  10. Gamma radiolysis and post-irradiation leaching of ion exchange resins

    International Nuclear Information System (INIS)

    Traboulsi, A.

    2012-01-01

    The knowledge of the behavior under irradiation and in presence of water of Ion Exchange Resins (IER) is very necessary to predict their impact on the environment during the storage phase and in a possible deep geological disposal. The IER studied are the MB400 mixed bed resin and its 'pure' anionic and cationic components. The experimental strategy used in this work was based on the use of chemometric tools permitting to estimate the effect of the irradiation atmosphere, the dose rate, the absorbed dose and the leaching temperature. The gaseous and water-soluble radiolysis products were analyzed by gas Mass Spectrometry (MS) and Ion Chromatography (IC). The IER generated principally H 2 g, CO 2 g and amines for which quantities depended of the resin nature and the irradiation conditions. The analysis of solid irradiated resins was investigated by Fourier Transformed Infrared (FTIR) and Nuclear Magnetic Resonance ( 13 C NMR) techniques. The last ones revealed structural modifications of the IER solid matrix in function of the experimental conditions. Their behavior in presence of water was studied during 143 days by characterization of the organic matter released after their post-irradiation leaching. The kinetics showed that all the water-soluble components were releasing at the first contact with water. The Total Organic Carbon (TOC) quantity released depends, according to the resin nature, either on the dose, either on the irradiation atmosphere. The dose rate has no effect on the degradation and the leaching of the MB400 resin, which behaved differently than its pure components. (author) [fr

  11. MR characterization of post-irradiation soft tissue edema

    International Nuclear Information System (INIS)

    Richardson, M.L.; Zink-Brody, G.C.; Patten, R.M.; Koh Wuijin; Conrad, E.U.

    1996-01-01

    Objective. Radiation therapy is often used to treat bone und soft tissue neoplasms, and commonly results in soft tissue edema in the radiation field. However, the time course, distribution and degree of this edema have not been well characterized. Our study was carried out to better define these features of the edema seen following neutron and photon radiation therapy. Results. In general, soft tissue signal intensity in the radiation field initially increased over time, peaking at about 6 months for neutron-treated patients and at about 12-18 months for photon-treated patients. Signal intensity then decreased slowly over time. However, at the end of the follow-up period, signal intensity remained elevated for most patients in both groups. Signal intensity in a particular tissue was greater and tended to persist longer on STIR sequences than on T2-weighted sequences. Survival analysis of signal intensity demonstrated much longer edema survival times for neutron-treated patients than for photon-treated patients. Signal intensity increase in the intramuscular septa persisted for much longer than for fat or muscle. A mild increase in size was noted in the subcutaneous fat and intramuscular septa. Muscle, on the other hand, showed a decrease in size following treatment. This was mild for the photon-treated group and more marked for the neutron-treated group. Conclusions. There is a relatively wide variation in the duration and degree of post-irradiation edema in soft tissues. This edema seems to persist longer in the intramuscular septa than in fat or muscle. Although the duration of follow-up was limited, our study suggests that this edema resolves in roughly half the photon-treated patients within 2-3 years post-treatment and in less than 20% of neutron-treated patients by 3-4 years post-treatment. Muscle atrophy was seen in both photon- and neutron-treated patients, but was more severe in the neutron-treated group. (orig./vhe). With 4 figs

  12. Tensile properties of vanadium alloys irradiated at 200{degrees}C in the HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Nowicki, L.; Smith, D.L. [Argonne National Lab., IL (United States)

    1997-08-01

    Vanadium alloys were irradiated in a helium environment to {approx}10 dpa at {approx}200{degrees}C in the High Flux Isotope Reactor (HFIR). This report presents results of postirradiation tests of tensile properties of laboratory heats of V-(1-18)Ti, V-4Cr-4Ti, V-8Cr-6Ti, V-9Cr-5Ti, V-3Ti-1Si, and V-3Ti-0.1C alloys. Because of significant loss of work-hardening capability, all alloys except V-18Ti exhibited a very low uniform plastic strain <1%. For V-Ti. The mechanism of the loss of work-hardening capability in the other alloys is not understood.

  13. Effects of ultraviolet irradiation and postirradiation incubation on heterogeneous nuclear RNA size in murine cells

    International Nuclear Information System (INIS)

    Ali, R.; Sauerbier, W.

    1978-01-01

    We have analyzed the decrease in synthesis of individual size classes of heterogeneous nuclear RNA (hnRNA) in ultraviolet (uv)-irradiated Merwin plasmacytoma (MPC-11) cells at various times of postirradiation incubation. HnRNA from nonirradiated control cells is distributed over a wide range from approximately 60S to 5S, with 42S RNA carrying more label than any other size class. HnRNA from uv-irradiated cells shows a dose-dependent shift in size distribution toward lower molecular weight. The size distribution of hnRNA synthesized after prolonged times of postirradiation incubation is restored toward normal, i.e., synthesis of long RNA molecules increases relative to the synthesis of short ones. Analysis of the total number of hnRNA chains synthesized during a 20-min [ 3 H]uridine pulse shows a considerable eduction in their number with increasing uv dose. Murine cell lines are excision-repair-deficient but capable of post replication repair inhibited by caffeine. HnRNA transcripts of cells incubated in its presence were studied. The caffeine, which has no effect on hnRNA size in control cells, inhibits to a considerable extent the restoration of full-length transcripts during postirradiation incubation. The lack of excision repair in MPC-11 was confirmed by the analysis of pyrimidine dimers in trichloracetic acid-insoluble and soluble fractions within 8 h of postirradiation incubation. The size of parental and daughter strand DNA in uv-irradiated cells was correlated with RNA transcript size. The parental DNA in these experiments does not change its size as a consequence of uv exposure and postirradiation incubation. In contrast, daughter DNA strands are short in uv-irradiated cells and they increase in size during postirradiation incubation to reach the size of parental strands after 8 h

  14. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, F.C., E-mail: zfc@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004 (China); Wang, F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, H.; Yu, B.D. [China Railway Shanhaiguan Bridge Group Co. LTD, Qinhuangdao 066205 (China)

    2017-01-02

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10{sup −4}, 5×10{sup −3}, and 5×10{sup −2} s{sup −1} were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  15. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    International Nuclear Information System (INIS)

    Chen, C.; Zhang, F.C.; Wang, F.; Liu, H.; Yu, B.D.

    2017-01-01

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10 −4 , 5×10 −3 , and 5×10 −2 s −1 were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  16. Genetic control over the processes of postirradiation recovery of a compact chromosome in micrococcus radiodurans

    International Nuclear Information System (INIS)

    Kudryashova, N.Yu.; Groshev, V.V.; Shestakov, S.V.

    1984-01-01

    X-irradiation of Micrococcus radiodurans cells with sublethal doses caused disturbances in the structure of a membrane-bound compact chromosome. Recovery of the compact chromosome occurred during the postirradiation incubation of the wild type cells and cells of the UVS-17 mutant deficient in DNA-polymerase. This process was blocked in cells of rec-30 mutant with the impaired system of genetic recombination: this is indicative of an important role played by rec-30 gene product in the postirradiation recovery of the compact chromosome in M. radiodurans cells

  17. Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles in proliferating and nonproliferating mammalian cells

    International Nuclear Information System (INIS)

    Korbelik, M.; Osmak, M.; Suhar, A.; Turk, V.; Skrk, J.

    1990-01-01

    Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles were examined in proliferating and nonproliferating Chinese hamster fibroblasts (V 79). The results show that there are significant alterations in cysteine and aspartic intracellular proteinases activity already in the early postirradiation period, which are different in proliferating and nonproliferating cells. Irradiation of the cells examined to low doses and up to 15 Gy induced an increase in cysteine proteinases activity in the early postexposure period, while at higher irradiation doses applied, the activity of these proteinases was decreased. These observations suggest that intracellular proteinases are actively participating in process involving recovery from radiation injury or cell killing. (orig.) [de

  18. Final irradiation and postirradiation data from the NRC/PNL instrumented assembly IFA-432

    International Nuclear Information System (INIS)

    Lanning, D.D.; Bradley, E.R.

    1986-02-01

    The instrumented six-rod test assembly IFA-432, sponsored by USNRC, operated in the Halden Reactor from December 1975 to May 1984, with surviving fuel thermocouples, neutron detectors and pressure transducers. Peak burnups of 46 MWd/kgM were achieved. Interim destructive examination data were obtained at peak burnups of 24 and 34 MWd/kgM. This paper presents a synopsis of the irradiation histories and postirradiation examination data for the high burnup rods. The postirradiation condition of the rods correlates well with their individual design parameters and operating conditions

  19. Estimations on uranium silicide fuel prototypes for their irradiation and postirradiation

    International Nuclear Information System (INIS)

    Sbaffoni, Maria M.

    2000-01-01

    The 'Silicide' project includes the qualification of this type of research reactor fuel to be used i.e. in the Argentine RA-3 and to confirm CNEA's role as an international supplier. The present paper shows complementary basic information for P-04 prototype post-irradiation, which is already under way, and some parameter values related to the new P-06 prototype to be taken into account for planning its irradiation and post-irradiation. The reliability of these values has been evaluated through comparison with experimental results. The reported results contribute, also, to a parallel study on the nuclear data libraries used in calculations for this type of reactor. (author)

  20. The postirradiation examination of the DC [Dry Capsule] melt dynamics experiments

    International Nuclear Information System (INIS)

    Fryer, C.P.; Hitchcock, J.T.

    1988-07-01

    The Dry Capsule experiment series investigates the coolability of dry fast reactor core debris through nuclear heating of actual reactor materials in order to obtain the thermal properties of dry debris, the nature of the transition from a debris bed to a molten pool, and the thermal and kinetic behavior of molten pools. The purpose is to develop a data base in support of model development. The work is jointly sponsored by the US Nuclear Regulatory Commission (USNRC), the Power Reactor and Nuclear Fuel Development Corporation (PNC, Japan), and Joint Research Centre, Ispra (EURATOM). This report provides a brief description of the two experiments in the Dry Capsule series and presents the results of the postirradiation examination. These tests investigated dry debris beds (/approximately/2kg) composed of pure UO 2 and mixed UO 2 and stainless steel. The beds were taken into melt to observe the growth of a molten pool in the UO 2 bed and the agglomeration and migration of steel in a composite bed. The peak measured temperature in the UO 2 bed was above 3100/degree/C. Approximately 50 percent of the urania formed a molten pool. Surrounding the molten pool and an overlying void was a high density urania crust. Lenticular pore formation and migration caused by urania vapor transport in the strong thermal gradient were seen in the urania crust. In the mixed UO 2 and steel bed, the peak measured temperature was 2600/degree/ C. All of the steel had been molten. Steel and urania migration were observed; both were thought to be caused by vapor transport mechanisms

  1. Tensile properties of orthodontic elastomeric ligatures.

    Science.gov (United States)

    Ahrari, F; Jalaly, T; Zebarjad, M

    2010-01-01

    Tensile properties of elastomeric ligatures become important when efficiency of orthodontic appliances is considered. The aim of this study was to compare tensile strength, extension to tensile strength, toughness and modulus of elasticity of elastomeric ligatures in both the as--received condition and after 28 days of immersion in the simulated oral environment. Furthermore, the changes that occurred in tensile properties of each brand of ligatures after 28 days were evaluated. Experimental-laboratory based. Elastomeric ligatures were obtained from different companies and their tensile properties were measured using Zwick testing machine in both the as-received condition and after 28 days of immersion in the simulated oral environment. The data were analyzed using independent sample t-tests, analysis of variance and Tukey tests. After 28 days, all the ligatures experienced a significant decrease in tensile strength, extension to tensile strength and toughness ( P tensile properties of different brands of ligatures in both conditions ( P tensile properties of different brands of ligatures, which should be considered during selection of these products.

  2. Elastic-plastic analysis of the SS-3 tensile specimen

    International Nuclear Information System (INIS)

    Majumdar, S.

    1998-01-01

    Tensile tests of most irradiated specimens of vanadium alloys are conducted using the miniature SS-3 specimen which is not ASTM approved. Detailed elastic-plastic finite element analysis of the specimen was conducted to show that, as long as the ultimate to yield strength ratio is less than or equal to 1.25 (which is satisfied by many irradiated materials), the stress-plastic strain curve obtained by using such a specimen is representative of the true material behavior

  3. In situ synchrotron X-ray diffraction studies of the effect of microstructure on tensile behavior and retained austenite stability of thermo-mechanically processed transformation induced plasticity steel

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Kun [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Liss, Klaus-Dieter [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234 (Australia); Timokhina, Ilana B. [Institute for Frontier Materials, Deakin University, Geelong, VIC 3217 (Australia); Pereloma, Elena V., E-mail: elenap@uow.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia)

    2016-04-26

    Transmission electron microscopy and in situ synchrotron high-energy X-ray diffraction were used to investigate the martensitic transformation and lattice strains under uniaxial tensile loading of Fe-Mn-Si-C-Nb-Mo-Al Transformation Induced Plasticity (TRIP) steel subjected to different thermo-mechanical processing schedules. In contrast with most of the diffraction analysis of TRIP steels reported previously, the diffraction peaks from the martensite phase were separated from the peaks of the ferrite-bainite α-matrix. The volume fraction of retained γ-austenite, as well as the lattice strain, were determined from the diffraction patterns recorded during tensile deformation. Although significant austenite to martensite transformation starts around the macroscopic yield stress, some austenite grains had already experienced martensitic transformation. Hooke’s Law was used to calculate the phase stress of each phase from their lattice strain. The ferrite-bainite α-matrix was observed to yield earlier than austenite and martensite. The discrepancy between integrated phase stresses and experimental macroscopic stress is about 300 MPa. A small increase in carbon concentration in retained austenite at the early stage of deformation was detected, but with further straining a continuous slight decrease in carbon content occurred, indicating that mechanical stability factors, such as grain size, morphology and orientation of the retained austenite, played an important role during the retained austenite to martensite transformation.

  4. Surface, structural and tensile properties of proton beam irradiated zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo, E-mail: yongskim@hanyang.ac.kr

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 10{sup 13} to 1 × 10{sup 16} protons/cm{sup 2}. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples’ surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson–Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  5. Porosity Defect Remodeling and Tensile Analysis of Cast Steel

    Directory of Open Access Journals (Sweden)

    Linfeng Sun

    2016-02-01

    Full Text Available Tensile properties on ASTM A216 WCB cast steel with centerline porosity defect were studied with radiographic mapping and finite element remodeling technique. Non-linear elastic and plastic behaviors dependent on porosity were mathematically described by relevant equation sets. According to the ASTM E8 tensile test standard, matrix and defect specimens were machined into two categories by two types of height. After applying radiographic inspection, defect morphologies were mapped to the mid-sections of the finite element models and the porosity fraction fields had been generated with interpolation method. ABAQUS input parameters were confirmed by trial simulations to the matrix specimen and comparison with experimental outcomes. Fine agreements of the result curves between simulations and experiments could be observed, and predicted positions of the tensile fracture were found to be in accordance with the tests. Chord modulus was used to obtain the equivalent elastic stiffness because of the non-linear features. The results showed that elongation was the most influenced term to the defect cast steel, compared with elastic stiffness and yield stress. Additional visual explanations on the tensile fracture caused by void propagation were also given by the result contours at different mechanical stages, including distributions of Mises stress and plastic strain.

  6. Surface, structural and tensile properties of proton beam irradiated zirconium

    Science.gov (United States)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 1013 to 1 × 1016 protons/cm2. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples' surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson-Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  7. LPTR irradiation of LLL vanadium tensile specimens and LLL Nb--1Zr tensile specimens

    International Nuclear Information System (INIS)

    MacLean, S.C.; Rowe, C.L.

    1977-01-01

    The LPTR irradiation of 14 LLL vanadium tensile specimens and 14 LLL Nb-1Zr tensile specimens is described. Sample packaging, the irradiation schedule and neutron fluences for three energy ranges are given

  8. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Y., E-mail: yano.yasuhide@jaea.go.jp [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T. [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Ukai, S.; Oono, N. [Materials Science and Engineering, Faculty of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Kimura, A. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, S. [Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Torimaru, T. [Nippon Nuclear Fuel Development Co., Ltd., 2163, Narita-cho, Oarai-machi, Ibaraki, 311-1313 (Japan)

    2017-04-15

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900–1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  9. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Science.gov (United States)

    Yano, Y.; Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T.; Ukai, S.; Oono, N.; Kimura, A.; Hayashi, S.; Torimaru, T.

    2017-04-01

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900-1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  10. Survey of post-irradiation examinations made of mixed carbide fuels

    International Nuclear Information System (INIS)

    Coquerelle, M.

    1997-01-01

    Post-irradiation examinations on mixed carbide, nitride and carbonitride fuels irradiated in fast flux reactors Rapsodie and DFR were carried out during the seventies and early eighties. In this report, emphasis was put on the fission gas release, cladding carburization and head-end gaseous oxidation process of these fuels, in particular, of mixed carbides. (author). 8 refs, 16 figs, 3 tabs

  11. Studies on Post-Irradiation DNA Degradation in Micrococcus Radiodurans, Strain RII51

    DEFF Research Database (Denmark)

    Auda, H.; Emborg, C.

    1973-01-01

    The influence of irradiation condition on post-irradiation DNA degradation was studied in a radiation resistant mutant of M. radiodurans, strain ${\\rm R}_{{\\rm II}}5$. After irradiation with 1 Mrad or higher more DNA is degraded in cells irradiated in wet condition than in cells irradiated with t...

  12. Hair transplantation for the the treatment of post-irradiation alopecia

    International Nuclear Information System (INIS)

    Kolasinski, J.; Kolenda, M.; Skowronek, J.

    2002-01-01

    Treatment of head and neck tumours and of leukaemia often necessitates radiotherapy. However; permanent alopecia in the scalp exposed to irradiation is a common problem. One of the effective methods of treatment of post-irradiation alopecia is hair transplantation. Over a period of 18 years 42 patients were treated at the Hair Clinic Poznan for post-irradiation alopecia. Due to the presence of numerous lesions in the donor and recipient scalp areas many modifications were introduced into alopecia correction. The treatment assured good cosmetic effects, free of the risk of complications. Scalps from occipital areas do not go bald when transferred to scalp areas affected by balding. On the contrary - they retain original properties, thus resulting in hair re-growth. Hair follicle transplantation is usually applied for the correction of androgenic alopecia in men and women although it may also be applied in post-trauma and post-irradiation alopecia treatment. Hair regrowth in radiotherapy patients occurs later than in androgenic alopecia patients. This phenomenon is caused by blood supply deficits in the recipient area. Autogenic hair follicle transplantation is a treatment of choice in the correction of post-irradiation alopecia, while the good cosmetic effects considerably improve the patients' quality of life. (author)

  13. Fine-needle aspiration cytology of postirradiation sarcomas, including angiosarcoma, with immunocytochemical confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, J.F.; Lannin, D.L.; Larkin, E.W.; Feldman, P.; Frable, W.J. (East Carolina Univ. School of Medicine, Greenville, NC (USA))

    1989-01-01

    Postirradiation sarcomas are an unusual but well-recognized late effect of cancer therapy. In this article, a fine-needle aspiration (FNA) series of four cases is presented. There were three female patients and one male patient, with an age range of 28-55 yr (mean, 41). Two of the patients were irradiated for uterine cervical carcinoma while the other two received irradiation for malignant lymphoma. The time interval to the development of the postirradiation sarcoma ranged from 10 to greater than 20 yr. There were a postirradiation synovial sarcoma of the buttock region, malignant fibrous histiocytoma of the bone (femur), and rhabdomyosarcoma and angiosarcoma of the retroperitoneum. A spectrum of cytologic findings was encountered, reflecting the specific types of sarcomas. Immunocytochemical studies performed on the aspirated material from the angiosarcoma demonstrated the utility of immunoperoxidase stains for ULEX europaeus agglutinin-1 (UEA-1) and, to a lesser degree, factor VIII-related antigen antibody, confirming the vascular nature of this malignancy. The FNA findings from all four cases demonstrated cytologic features that allowed recognition of this unusual complication of irradiation treatment. This article confirms the utility of FNA cytology in following patients with previous malignancies and differentiating a postirradiation sarcoma from recurrent carcinoma.

  14. Fine-needle aspiration cytology of postirradiation sarcomas, including angiosarcoma, with immunocytochemical confirmation

    International Nuclear Information System (INIS)

    Silverman, J.F.; Lannin, D.L.; Larkin, E.W.; Feldman, P.; Frable, W.J.

    1989-01-01

    Postirradiation sarcomas are an unusual but well-recognized late effect of cancer therapy. In this article, a fine-needle aspiration (FNA) series of four cases is presented. There were three female patients and one male patient, with an age range of 28-55 yr (mean, 41). Two of the patients were irradiated for uterine cervical carcinoma while the other two received irradiation for malignant lymphoma. The time interval to the development of the postirradiation sarcoma ranged from 10 to greater than 20 yr. There were a postirradiation synovial sarcoma of the buttock region, malignant fibrous histiocytoma of the bone (femur), and rhabdomyosarcoma and angiosarcoma of the retroperitoneum. A spectrum of cytologic findings was encountered, reflecting the specific types of sarcomas. Immunocytochemical studies performed on the aspirated material from the angiosarcoma demonstrated the utility of immunoperoxidase stains for ULEX europaeus agglutinin-1 (UEA-1) and, to a lesser degree, factor VIII-related antigen antibody, confirming the vascular nature of this malignancy. The FNA findings from all four cases demonstrated cytologic features that allowed recognition of this unusual complication of irradiation treatment. This article confirms the utility of FNA cytology in following patients with previous malignancies and differentiating a postirradiation sarcoma from recurrent carcinoma

  15. Evolution of tensile design stresses for lumber

    Science.gov (United States)

    William L. Galligan; C. C. Gerhards; R. L. Ethington

    1979-01-01

    Until approximately 1965, allowable design stresses for lumber in tension were taken as equal to those assigned for bending. As interest in tensile properties increased, testing machines were designed specifically to stress lumber in tension. Research results that accumulated on tensile tests of full-size lumber suggested lower design stresses for tension than for...

  16. Dilatometer for use in tensile tests

    NARCIS (Netherlands)

    Coumans, W.J.; Heikens, D.

    1980-01-01

    An accurate dilatometer is described which permits simultaneous and automatic recording of sample vol. change during tensile tests on a com. tester. Liq. displacements in the dilatometer capillary, which correspond to vol. changes of the sample, are detected by a cond. meter. Tensile load is

  17. Shear Wave Elastography--A New Quantitative Assessment of Post-Irradiation Neck Fibrosis.

    Science.gov (United States)

    Liu, K H; Bhatia, K; Chu, W; He, L T; Leung, S F; Ahuja, A T

    2015-08-01

    Shear wave elastography (SWE) is a new technique which provides quantitative assessment of soft tissue stiffness. The aim of this study was to assess the reliability of SWE stiffness measurements and its usefulness in evaluating post-irradiation neck fibrosis. 50 subjects (25 patients with previous radiotherapy to the neck and 25 sex and age-matched controls) were recruited for comparison of SWE stiffness measurements (Aixplorer, Supersonic Imagine). 30 subjects (16 healthy individuals and 14 post-irradiated patients) were recruited for a reliability study of SWE stiffness measurements. SWE stiffness measurements of the sternocleidomastoid muscle and the overlying subcutaneous tissues of the neck were made. The cross-sectional area and thickness of the sternocleidomastoid muscle and the overlying subcutaneous tissue thickness of the neck were also measured. The post-irradiation duration of the patients was recorded. The intraclass correlation coefficients for the intraoperator and interoperator reliability of deep and subcutaneous tissue SWE stiffness ranged from 0.90-0.99 and 0.77-0.94, respectively. The SWE stiffness measurements (mean +/- SD) of deep and subcutaneous tissues were significantly higher in the post-irradiated patients (64.6 ± 46.8 kPa and 63.9 ± 53.1 kPa, respectively) than the sex and age-matched controls (19.9 ± 7.8 kPa and 15.3 ± 8.37 respectively) (p < 0.001). The SWE stiffness increased with increasing post-irradiation therapy duration in the Kruskal Wallis test (p < 0.001) and correlated with muscle atrophy and subcutaneous tissue thinning (p < 0.01). SWE is a reliable technique and may potentially be an objective and specific tool in quantifying deep and subcutaneous tissue stiffness, which in turn reflects the severity of neck fibrosis. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Tensile properties of irradiated TZM and tungsten

    International Nuclear Information System (INIS)

    Steichen, J.M.

    1975-04-01

    The effect of neutron irradiation on the elevated temperature tensile properties of TZM and tungsten has been experimentally determined. Specimens were irradiated at a temperature of approximately 720 0 F to fluences of 0.4 and 0.9 x 10 22 n/cm 2 (E greater than 0.1 MeV). Test parameters for both control and irradiated specimens included strain rates from 3 x 10 -4 to 1 s -1 and temperatures from 72 to 1700 0 F. The results of these tests were correlated with a rate-temperature parameter (T ln A/epsilon) to provide a concise description of material behavior over the range of deformation conditions of this study. The yield strength of the subject materials was significantly increased by decreasing temperature, increasing strain rate, and increasing fluence. Ductility was significantly reduced at any temperature or strain rate by increasing fluence. Cleavage fractures occurred in both unirradiated and irradiated specimens when the yield strength was elevated to the effective cleavage stress by temperature and/or strain rate. Neutron irradiation for the conditions of this study increased the ductile-to-brittle transition temperature of tungsten by approximately 300 0 F and TZM by approximately 420 0 F. (U.S.)

  19. Tensile and compressive failure modes of laminated composites loaded by fatigue with different mean stress

    Science.gov (United States)

    Rotem, Assa

    1990-01-01

    Laminated composite materials tend to fail differently under tensile or compressive load. Under tension, the material accumulates cracks and fiber fractures, while under compression, the material delaminates and buckles. Tensile-compressive fatigue may cause either of these failure modes depending on the specific damage occurring in the laminate. This damage depends on the stress ratio of the fatigue loading. Analysis of the fatigue behavior of the composite laminate under tension-tension, compression-compression, and tension-compression had led to the development of a fatigue envelope presentation of the failure behavior. This envelope indicates the specific failure mode for any stress ratio and number of loading cycles. The construction of the fatigue envelope is based on the applied stress-cycles to failure (S-N) curves of both tensile-tensile and compressive-compressive fatigue. Test results are presented to verify the theoretical analysis.

  20. Tensile deformation and failure of North American porcupine quills

    Energy Technology Data Exchange (ETDEWEB)

    Chou, S.F.; Overfelt, R.A., E-mail: overfra@auburn.edu

    2011-12-01

    Although the mechanical properties of some keratin-based biological materials have been extensively studied (i.e., wool) and others are beginning to be studied (e.g., horn, hooves and avian quills), data on the properties of porcupine quill are less common. Porcupine quill is a keratin-based biological material composed of a cylindrical outer shell with an inner foam core. The present paper reports on the physical characteristics, tensile properties and fracture behavior of North American porcupine quills conditioned at relative humidities of 65% and 100%. Increasing the water content decreased the tensile stiffness and strength and increased the strain at fracture of the porcupine quills. The tensile fracture strength of porcupine quill was found to be 146 MPa at 65% RH and 60 MPa at 100% RH. Although these values compare favorably with reported values for African porcupine quill, reported values of the tensile strengths of wool with similar moisture contents are considerably higher. The initial moduli of porcupine quill (2700 MPa at 65% RH and 1000 MPa at 100% RH) compare favorably to those reported for wool but are considerably less than previous reports for African porcupine quill. The engineering strains at fracture were measured as 25% at 65% RH and 49% at 100% RH and these values are also comparable to other keratin-based mammalian materials. Scanning electron microscopy of the fracture surfaces of porcupine quills revealed that the cylindrical outer shells of quills are composed of 2-3 layers with distinctly different fracture characteristics, especially when the samples contain 100% RH. The outer layer of the porcupine quill shell appears to resist the plasticizing effects of moisture and appears to exhibit considerably less ductility than the inner layers, perhaps due to the presence of hydrophobic lipids in the outer layer. Highlights: {yields} We characterize the tensile properties of north American porcupine quill. {yields} Elastic modulus, tensile

  1. Tensile properties of neutron irradiated 316Ti and 15-15Ti steels

    International Nuclear Information System (INIS)

    Fissolo, A.; Levy, V.; Seran, J.L.; Maillard, A.; Royer, J.; Rabouille, O.

    1992-01-01

    This paper deals with the tensile behavior of CW316Ti and CW15-15Ti Phenix fuel pin cladding. The tensile tests were conducted on defueled tubes irradiated up to 115 dpa 3 in the 400-640 deg C temperature range. Test temperature corresponds essentially to irradiation temperature. The results emphasize that although irradiation induces a reduction of ductility, failure always occurs with significant plastic deformation even for the most irradiated clads. (author). 15 refs., 12 figs., 1 tab

  2. Miniature specimen technology for postirradiation fatigue crack growth testing

    International Nuclear Information System (INIS)

    Mervyn, D.A.; Ermi, A.M.

    1979-01-01

    Current magnetic fusion reactor design concepts require that the fatigue behavior of candidate first wall materials be characterized. Fatigue crack growth may, in fact, be the design limiting factor in these cyclic reactor concepts given the inevitable presence of crack-like flaws in fabricated sheet structures. Miniature specimen technology has been developed to provide the large data base necessary to characterize irradiation effects on the fatigue crack growth behavior. An electrical potential method of measuring crack growth rates is employed on miniature center-cracked-tension specimens (1.27 cm x 2.54 cm x 0.061 cm). Results of a baseline study on 20% cold-worked 316 stainless steel, which was tested in an in-cell prototypic fatigue machine, are presented. The miniature fatigue machine is designed for low cost, on-line, real time testing of irradiated fusion candidate alloys. It will enable large scale characterization and development of candidate first wall alloys

  3. Fabrication of ORNL Fuel Irradiated in the Peach Bottom Reactor and Postirradiation Examination of Recycle Test Elements 7 and 4

    International Nuclear Information System (INIS)

    Long, Jr. E.L.

    2001-01-01

    Seven full-sized Peach Bottom Reactor fuel elements were fabricated in a cooperative effort by Oak Ridge National Laboratory (ORNL) and Gulf General Atomic (GGA) as part of the National HTGR Fuel Recycle Development Program. These elements contain bonded fuel rods and loose beds of particles made from several combinations of fertile and fissile particles of interest for present and future use in the High-Temperature Gas-Cooled Reactor (HTGR). The portion of the fuel prepared for these elements by ORNL is described in detail in this report, and it is in conjunction with the GGA report (GA-10109) a complete fabrication description of the test. In addition, this report describes the results obtained to date from postirradiation examination of the first two elements removed from the Peach Bottom Reactor, RTE-7 and -4. The fuel examined had relatively low exposure, up to about 1.5 x 10 21 neutrons/cm* fast (>0.18 MeV) fluence, compared with the peak anticipated HTGR fluence of 8.0 x 10 21 , but it has performed well at this exposure. Dimensional data indicate greater irradiation shrinkage than expected from accelerated test data to higher exposures. This suggests that either the method of extrapolation of the higher exposure data back to low exposure is faulty, or the behavior of the coated particles in the neutron spectrum characteristic of the accelerated tests does not adequately represent the behavior in an HTGR spectrum

  4. Post-Irradiation Examination Test of the Parts of X-Gen Nuclear Fuel Assembly

    International Nuclear Information System (INIS)

    Ahn, S. B.; Ryu, W. S.; Choo, Y. S.

    2008-08-01

    The mechanical properties of the parts of a nuclear fuel assembly are degraded during the operation of the reactor, through the mechanism of irradiation damage. The properties changes of the parts of the fuel assembly should be quantitatively estimated to ensure the safety of the fuel assembly and rod during the operation. The test techniques developed in this report are used to produce the irradiation data of the grid 1x1 cell spring, the grid 1x1 cell, the spring on one face of the 1x1 cell, the inner/outer strip of the grid and the welded part. The specimens were irradiated in the CT test hole of HANARO of a 30 MW thermal output at 300 deg. C during about 100 days From the spring test of mid grid 1x1 cell and grid plate, the irradiation effects can be examined. The irradiation effects on the irradiation growth also were occurred. The buckling load of mid grid 1x1 cell does not change with a neutron irradiation. From the tensile tests, the strengths increased but the elongations decreased due to an irradiation. The tensile test and microstructure examination of the spot and fillet welded parts are performed for the evaluation of an irradiation effects. Through these tests of components, the essential data on the fuel assembly design could be obtained. These results will be used to update the irradiation behavior databases, to improve the performance of fuel assembly, and to predict the service life of the fuel assembly in a reactor

  5. Behaviour of eggshell membranes at tensile loading

    Czech Academy of Sciences Publication Activity Database

    Strnková, M.J.; Nedomová, Š.; Trnka, Jan; Buchar, J.; Kumbár, V.

    46 B, December (2014), s. 44-48 ISSN 0324-1130 Institutional support: RVO:61388998 Keywords : eggshell membrane * tensile loading * loading rate * stress * strain strength Subject RIV: GM - Food Processing Impact factor: 0.201, year: 2014

  6. Tensile Properties of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Řehořek, Lukáš; Chlup, Zdeněk

    2009-01-01

    Roč. 409, - (2009), s. 168-175 ISSN 1013-9826. [Fractography of Advanced Ceramics /3./. Stará Lesná, 07.09.2008-10.09.2008] R&D Projects: GA ČR(CZ) GA106/06/0724; GA ČR GD106/05/H008 Institutional research plan: CEZ:AV0Z20410507 Keywords : tensile test * ceramics foam * open porosity * tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  7. Tensile Behaviour of Open Cell Ceramic Foams

    Czech Academy of Sciences Publication Activity Database

    Řehořek, Lukáš; Dlouhý, Ivo; Chlup, Zdeněk

    2009-01-01

    Roč. 53, č. 4 (2009), s. 237-241 ISSN 0862-5468 R&D Projects: GA ČR GA101/09/1821; GA ČR GD106/09/H035 Institutional research plan: CEZ:AV0Z20410507 Keywords : Tensile test * Ceramics foam * Open porosity * Tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.649, year: 2009

  8. Postirradiation lumbosacral radiculopathy following seminoma treatment presenting as flaccid neuropathic bladder: a case report.

    LENUS (Irish Health Repository)

    Raheem, Omer A

    2012-02-01

    INTRODUCTION: Postirradiation lumbosacral syndrome is a radiculopathy induced by radiation injury to the spinal cord. Its usual presentation is motor deficit and or sensory loss involving the lower limbs. Visceral involvement has not been reported previously. CASE PRESENTATION: We describe a case of severe hypotonic bladder caused by radiation-induced spinal cord injury following treatment of stage Iota testicular seminoma in a 38-year-old Caucasian man who had undergone radical orchidectomy and prophylactic paraaortic lymph node irradiation for stage Iota seminoma. Three years later he had clinical and urodynamic findings of hypotonic bladder. The magnetic resonance imaging results suggested a radiation-induced injury. CONCLUSION: Such an unusual presentation of the syndrome of postirradiation lumbosacral radiculopathy can impose a clinical challenge to practicing clinicians. Future studies are required to further delineate the mechanism of injury and further management plans.

  9. Postirradiation lumbosacral radiculopathy following seminoma treatment presenting as flaccid neuropathic bladder: a case report

    LENUS (Irish Health Repository)

    Raheem, Omer A

    2011-04-14

    Abstract Introduction Postirradiation lumbosacral syndrome is a radiculopathy induced by radiation injury to the spinal cord. Its usual presentation is motor deficit and or sensory loss involving the lower limbs. Visceral involvement has not been reported previously. Case presentation We describe a case of severe hypotonic bladder caused by radiation-induced spinal cord injury following treatment of stage Ι testicular seminoma in a 38-year-old Caucasian man who had undergone radical orchidectomy and prophylactic paraaortic lymph node irradiation for stage Ι seminoma. Three years later he had clinical and urodynamic findings of hypotonic bladder. The magnetic resonance imaging results suggested a radiation-induced injury. Conclusion Such an unusual presentation of the syndrome of postirradiation lumbosacral radiculopathy can impose a clinical challenge to practicing clinicians. Future studies are required to further delineate the mechanism of injury and further management plans.

  10. Chemical changes after irradiation and post-irradiation storage in tilapia and Spanish mackerel

    International Nuclear Information System (INIS)

    Al-Kahtani, H.A.; Abu-Tarboush, H.M.; Bajaber, A.S.; Atia, M.; Abou-Arab, A.A.; El-Mojaddidi, M.A.

    1996-01-01

    Influence of gamma irradiation (1.5-10 kGy) and post-irradiation storage up to 20 days at 2 +/- 2 degrees C on some chemical criteria of tilapia and spanish mackerel were studied. Total volatile basic nitrogen formation was lower in irradiated fish than in the unirradiated. Irradiation also caused a larger increase in thiobarbituric acid values which continued gradually during storage. Some fatty acids decreased by irradiation treatments at all doses. Thiamin loss was more severe at higher doses (greater than or equal to 4.5 kGy), whereas riboflavin was not affected. Alpha and gamma tocopherols of tilapia and alpha, beta, gamma, and delta tocopherols, in Spanish mackerel, decreased with increased dose and continued to decrease during 20-day post-irradiation storage

  11. Tensile strength and durability characteristics of high-performance fiber reinforced concrete

    International Nuclear Information System (INIS)

    Ramadoss, P.; Nagamani, K.

    2008-01-01

    This paper presents investigations towards developing a better understanding of the contribution of steel fibers to the tensile strength of high-performance fiber reinforced concrete (HPFRC). For 32 series of mixes, flexural and splitting tensile strengths were determined at 28 days. The variables investigated were fiber volume fraction (0%, 0.5%, 1% and 1.5% with an aspect of 80), silica fume replacement level (SF/CM=0.05 and 0.10) and matrix composition (w/cm ratios ranging from 0.25 t 0.40). The influence of fiber content in terms of fiber reinforcing index on the flexural and splitting tensile strengths of HPFRC is presented. Comparative studies were performed on the tensile behavior of SFRC measured by two different loading tests: flexural test and splitting test. Based on the test results, using the least square method, empirical expressions were developed to predict 28-day tensile strength of HPFRC in terms of fiber reinforcing index. Durability tests were carried out to examine the performance of the SFRC. Relationship between flexural and splitting tensile strengths has been developed using regression analysis. The experimental values of previous researchers were compared with the values predicted by the empirical equations and the absolute variation obtained was within 6% and 5% for flexural and splitting tensile strengths respectively. (author)

  12. Postirradiation recovery of the skeletal muscle of rats of various age

    International Nuclear Information System (INIS)

    Popova, M.F.; Bulyakova, N.V.

    1977-01-01

    The skeletal muscle of young rats (particularly of 3-and 4-week old ones) exposed to local irradiation of 2000 R was markedly repaired in the course of one month after irradiation . This was indicated by a restored ability of the muscle for posttraumatic regeneration. A regeneration ability of the irradiated muscle of old rats was not restored. The more intensive processes of postirradiation recovery in muscles of young rats may be explained by their more active metabolism

  13. Postirradiation examination of light water reactor fuel: a United States perspective

    International Nuclear Information System (INIS)

    Neimark, L.A.; Ocken, H.

    1980-01-01

    Poolside and hot-cell postirradiation examination (PIE) have played and will continue to play a significant role in the US LWR program. The principal uses of PIE are in fuel surveillance, fuel improvement, and failure analysis programs and in the postmortem analysis of safety-related tests. Institutional problems associated with fuel shipping, waste disposal, and fuel disposal can be expected to pose obstacles to hot-cell examinations and likely result in more sophisticated poolside examinations

  14. Postirradiation Leiomyosarcoma of Rectum Presenting as a Polyp: Case Report and Review of the Literature.

    Science.gov (United States)

    Jayakumar, Rajeswari; Basu, Prithwijit Patrick; Huang, Tao; Axiotis, Constantine A

    2016-04-01

    Radiation-induced leiomyosarcomas of the gastrointestinal tract are rare. Very few cases have been documented to date. The histological similarity to gastrointestinal stromal tumor has raised doubts if many of the cases originally reported to be leiomyosarcoma before the widespread use of CD117 were indeed gastrointestinal stromal tumors. We present a case of post-irradiation leiomyosarcoma presenting as a rectal polyp and review the literature. © The Author(s) 2015.

  15. Information for irradiation and post-irradiation of the silicide fuel element prototype P-07

    International Nuclear Information System (INIS)

    Abbate, Maximo J.; Sbaffoni, Maria M.

    2003-01-01

    Included in the 'Silicides' Project, developed by the Nuclear Fuels Department of the National Atomic Energy Commission (CNEA), it is foreseen the qualification of this type of fuel for research reactors in order to be used in the Argentine RA-3 reactor and to confirm the CNEA as an international supplier. The paper presents basic information on several parameters corresponding to the new silicide prototype, called P-07, to be taken into account for its irradiation, postirradiation and qualification. (author)

  16. The results of postirradiation examinations of VVER-1000 and VVER-440 fuel rods

    Science.gov (United States)

    Dubrovin, K. P.; Ivanov, E. G.; Strijov, P. N.; Yakovlev, V. V.

    1991-02-01

    The paper presents the results of postirradiation examination of the fuel rods having different fuel-cladding gaps, pellet densities, pellet inner diameters and so on. The fuel rods were irradiated in the material science reactor (MR) of the Kurchatov Institute of Atomic Energy and at 4 unit of the Novo-Voronezh nuclear powerplant. Some data on fission gas release and rod geometry and compared with computer code predictions.

  17. Irradiation behavior evaluation of oxide dispersion strengthened ferritic steel cladding tubes irradiated in JOYO

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Shinichiro, E-mail: yamashita.shinichiro@jaea.go.jp; Yano, Yasuhide; Ohtsuka, Satoshi; Yoshitake, Tsunemitsu; Kaito, Takeji; Koyama, Shin-ichi; Tanaka, Kenya

    2013-11-15

    Irradiation behavior of ODS steel cladding tubes was evaluated for the further progress in understanding of the neutron-irradiation effects on ODS steel. Two types of ODS (9Cr–ODS{sub F}/M, 12Cr–ODS{sub F}) steel cladding tubes with differences in basic compositions and matrix phases were irradiated in JOYO. Post-irradiation examination data concerning hardness, ring tensile property, and microstructure were obtained. Hardness measurement after irradiation showed that there was an apparent irradiation temperature dependence on hardness for 9Cr–ODS{sub F}/M steel whereas no distinct temperature dependence for 12Cr–ODS{sub F} steel. Also, there was no significant change in tensile strengths after irradiation below 923 K, but those above 1023 K up to 6.6 × 10{sup 26} n/m{sup 2} (E > 0.1 MeV) were decreased by about 20%. TEM observations showed that the radiation-induced defect cluster formation during irradiation was suppressed because of high density sink site for defect such as initially-existed dislocation, and precipitate interfaces. In addition, oxide particles were stable up to the maximum doses of this irradiation test.

  18. Sensitization of Micrococcus radiophilus to gamma-rays by postirradiation incubation with chloramphenicol or at nonpermissive temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, S; Harsojo,; Matsuyama, A [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1980-12-01

    M. radiophilus was sensitized to gamma-rays by postirradiation incubation at 42/sup 0/C or at 30/sup 0/C in the presence of chloramphenicol. Radiation induced strand scissions and alkali labile bonds in DNA were repaired by post-irradiation incubation under normal conditions. However, these lesions were repaired only partially during the incubation at 42/sup 0/C or in the presence of chloramphenicol.

  19. Effect of disodium cromoglycate (DSCG) and antihistamines on postirradiation cerebral blood flow and plasma levels of histamine and neurotensin

    International Nuclear Information System (INIS)

    Cockerham, L.G.; Pautler, E.L.; Carraway, R.E.; Cochrane, D.E.; Hampton, J.D.

    1988-01-01

    In an attempt to elucidate mechanisms underlying the irradiation-induced decrease in regional cerebral blood flow (rCBF) in primates, hippocampal and visual cortical blood flows of rhesus monkeys were measured by hydrogen clearance, before and after exposure to 100 Gy, whole-body, gamma irradiation. Systemic blood pressures were monitored simultaneously. Systemic arterial plasma histamine and neurotensin levels were determined preirradiation and postirradiation. Compared to control animals, the irradiated monkeys exhibited an abrupt decline in systemic blood pressure to 23% of the preirradiation level within 10 min postirradiation, falling to 12% by 60 min. A decrease in hippocampal blood flow to 32% of the preirradiation level was noted at 10 min postirradiation, followed by a slight recovery to 43% at 30 min and a decline to 23% by 60 min. The cortical blood flow for the same animals showed a steady decrease to 29% of the preirradiation levels by 60 min postirradiation. Animals given the mast cell stabilizer disodium cromoglycate and the antihistamines mepyramine and cimetidine before irradiation did not exhibit an abrupt decline in blood pressure but displayed a gradual decrease to a level 33% below preirradiation levels by 60 min postirradiation. Also, the treated, irradiated monkeys displayed rCBF values that were not significantly different from the nonirradiated controls. The plasma neurotensin levels in the irradiated animals, treated and untreated, indicated a nonsignificant postirradiation increase above control levels. However, the postirradiation plasma histamine levels in both irradiated groups showed an increase of approximately 1600% above the preirradiation levels and the postirradiation control levels

  20. A case of postirradiation cutaneous angiosarcoma on the chest after radical mastectomy without any therapies

    International Nuclear Information System (INIS)

    Hirai, Nobuyuki; Suzuki, Yutaka

    2009-01-01

    The patient was a 78-year-old woman who had undergone radical mastectomy for left breast cancer, followed by irradiation to the chest wall about 40 years earlier. In the fall of 2006, small purpura appeared around the surgical scar in the left chest. Because it had spread on the chest gradually, she was seen at this hospital on August 28, 2007, when a purple red brownish induration 7.5 x 3.5 cm in diameter was noted on the left chest. A biopsy gave the histopathological diagnosis of angiosarcoma. According to her clear intention, no therapies have done and thus the tumor has spread over the entire left chest. But she is doing well over two years since she had noticed the purpura without any therapies. Postirradiation cutaneous angiosarcoma is rare, but carries very poor prognosis. In Japan, the number of patients with breast cancer is increasing rapidly, and the number of patients with postirradiation cutaneous angiosarcoma after breast cancer treatment will increase. Surgeons must inform the patients about the possibility that irradiation can cause cutaneous angiosarcoma, and must strictly follow the post-irradiation patients. (author)

  1. Evaluation Of Radioactivity Of Released Air During Postirradiation Examination At The RMI

    International Nuclear Information System (INIS)

    Prayitno, B.; Eko, Pudjadi

    1998-01-01

    Radioactivity evaluation of released air during post-irradiation examination at RMI has been done since january 1993 to december 1996. The released air radioactivity has been observed during post-irradiation examinations of irradiated fuels and structure materials in the hot cell. Analysis method employed has been by air sampling and measurement of the alpha and beta activities by using alpha beta aerosol LB 150 D model. Air release from RMI was sucked by using an air pump having 40 m3/hour capacity which is equipped with a 200 mm diameter filter paper. The filter paper is automatically counted by the detector of the instrument. The average of the daily maximum counting result in a month has been used as monthly data. It has been shown that there have been increase in the released air radioactivity caused by the post-irradiation examination activity. The data of the released air activity obtained have been used to calculate the radioactivity concentration and radioactivity on the soil surface based on Gauss Plumes. The calculation result have shown that the alpha and beta radioactivity concentration at stacks and on the soil surface are less then the set maximum permissible concentration (MPC)

  2. Clinical analysis of post-irradiation sensorineural hearing loss in patients suffering from nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Lu Xueguan; Liu Zhiyong; Zhang Liyuan; Tian Ye

    2005-01-01

    Objective: To investigate the incidence of post-irradiation sensorineural hearing loss (SNHL) in patients suffering from nasopharyngeal carcinoma and to evaluate its potentially contributing factors. Methods: Pure tonetest and impedance audiography were carried out in patients suffering from nasopharyngeal carcinoma with a post-irradiation follow-up time over 1 year. Additionally, the test results were combined with clinical data and analyzed retrospectively. Results: The follow-up time of all patients ranged from 12 to 94 months (median 53 months). The incidences of SNHL at low and high frequencies were 8% and 42% respectively. Univariate analysis showed that patient's age and follow-up time affected the incidence of SNHL at high frequencies (t=2.051, P=0.0269; t=2.978, P=0.0011), but sex, preirradiation subjective hearing loss, irradiation dose and chemotherapy including cisplatin had no significance. Multivariate analysis by Binary Logistic Regression revealed that the risk of SNHL was correlated with patient's age and follow-up time (P=0.02; P=0.009). Conclusion: Post-irradiation SNHL at high frequencies in patients suffering from nasopharyngeal carcinoma is more common than that at low frequencies. The independent prognostic factors for development of SNHL at high frequencies are patient's age and follow-up time. But the role of preirradiation hearing level ,irradiation dose and chemotherapy including cisplatin are not conclusive and further research is needed. (authors)

  3. A Novel Geometry for Shear Test Using Axial Tensile Setup

    Directory of Open Access Journals (Sweden)

    Sibo Yuan

    2018-05-01

    Full Text Available This paper studies a novel geometry for the in-plane shear test performed with an axial electromechanical testing machine. In order to investigate the influence of the triaxiality rate on the mechanical behavior, different tests will be performed on the studied material: simple tensile tests, large tensile tests and shear tests. For the whole campaign, a common equipment should be employed to minimize the impact of the testing device. As a consequence, for the shear tests, the geometry of the specimen must be carefully designed in order to adapt the force value and make it comparable to the one obtained for the tensile tests. Like most of the existing shear-included tensile test specimens, the axial loading is converted to shear loading at a particular region through the effect of geometry. A symmetric shape is generally preferred, since it can restrict the in-plane rotation of the shear section, keep shear increasing in a more monotonic path and double the force level thanks to the two shear zones. Due to the specific experimental conditions, such as dimensions of the furnace and the clamping system, the position of the extensometer or the restriction of sheet thickness (related to the further studies of size effect at mesoscale and hot temperature, several geometries were brought up and evaluated in an iterative procedure via finite element simulations. Both the numerical and experimental results reveal that the final geometry ensures some advantages. For instance, a relatively low triaxiality in the shear zone, limited in-plane rotation and no necking are observed. Moreover, it also prevents any out-of-plane displacement of the specimen which seems to be highly sensitive to the geometry, and presents a very limited influence of the material and the thickness.

  4. Tensile and Flexural Test on Kenaf Hybrid Composites

    Science.gov (United States)

    Salleh, Z.; Yunus, S.; Masdek, N. R. N. M.; Taib, Y. M.; Azhar, I. I. S.; Hyie, K. M.

    2018-03-01

    The widely use of synthetic materials like carbon and fiberglass in various industries such as automotive and aircraft has lead to human health and environment problems. Therefore, the use of natural fibres such as kenaf has received higher attention as reinforcement. Kenaf or the scientific name is Hibiscus Cannabinus. L is one of the group of Malvecea plant which in the early days, the application of kenaf served only rope and canvas. However, it has more advantages than synthetic materials such as; widely availaible, renewable, lightweight, non-abbrasiveness during processing, high specific strength, free from health hazard and biodegradeable. This study was carried out to investigate the effects of different arrangement of kenaf and fiberglass composites on Young’s Modulus. The material composite was hardened with polyester resin and their properties was characterized. The tensile and the flexural properties is determined using an Instron universal tensile testing machine and carried out by following ASTM D3039 for tensile and ASTM D790 for a flexural test. The experimental program was designed to correlate the flexural and tensile Young’s Modulus of kenaf and fiberglass composite under the same load condition but different arrangement of kenaf and fiberglass on the mold . The resistance to change in shape was described by the behavior and characteristic of the composite materials. The stiffness or the elastic modulus of the composite material was determined at the end of the experiment. The results obtained show that the [±90FG/0/90/90/0/±90FG] kenaf/fiberglass composite arrangement has the highest elastic value.

  5. Monitoring tensile damage evolution in Nextel 312/BlackglasTM composites

    International Nuclear Information System (INIS)

    Kim, Jeongguk; Liaw, Peter K.

    2005-01-01

    Tensile damage evolution was monitored with the aid of nondestructive evaluation (NDE) techniques. Several NDE methods, such as ultrasonic testing (UT), infrared (IR) thermography, and acoustic emission (AE) techniques, were employed to analyze damage evolution during tensile testing of Nextel 312/Blackglas TM composites. Prior to tensile testing, UT was used to characterize the initial defect distribution of the samples. During tensile testing, AE sensors and an IR camera were used for in situ monitoring of the progressive damage of the samples. AE provided the amounts of damage evolution in terms of the AE intensity and/or energy, and the IR camera was used to obtain the temperature changes during the test. Microstructural characterization using scanning electron microscopy (SEM) was performed to investigate the fracture mechanisms and modes of Nextel 312/Blackglas TM samples. Moreover, SEM characterization was used to document failure behavior, and to show comparable results with NDE signatures

  6. High strain rate tensile properties of annealed 2 1/4 Cr--1 Mo steel

    International Nuclear Information System (INIS)

    Klueh, R.L.; Oakes, R.E. Jr.

    1975-01-01

    The high strain rate tensile properties of annealed 2 1 / 4 Cr-1 Mo steel were determined and the tensile behavior from 25 to 566 0 C and strain rates of 2.67 x 10 -6 to 144/s were described. Above 0.1/s at 25 0 C, both the yield stress and the ultimate tensile strength increased rapidly with increasing strain rate. As the temperature was increased, a dynamic strain aging peak appeared in the ultimate tensile strength-temperature curves. The peak height was a maximum at about 350 0 C and 2.67 x 10 -6 /s. With increasing strain rate, a peak of decreased height occurred at progressively higher temperatures. The major effect of strain rate on ductility occurred at elevated temperatures, where a decrease in strain rate caused an increase in total elongation and reduction in area

  7. The Effects of Fe-Particles on the Tensile Properties of Al-Si-Cu Alloys

    Directory of Open Access Journals (Sweden)

    Anton Bjurenstedt

    2016-12-01

    Full Text Available The effect of Fe-rich particles has been a topic for discussion in the aluminum casting industry because of the negative impact they exert on the mechanical properties. However, there are still contradictions on the effects of various morphologies of Fe-particles. In this study, microstructural characterization of tensile tested samples has been performed to reveal how unmodified and modified Fe-rich particles impact on the tensile behavior. Analysis of additions of Fe modifiers such as Mn and Cr, showed higher amounts of primary Fe-rich particles (sludge with increased porosity and, as result, degraded tensile properties. From the fracture analysis of tensile tested hot isostatic pressed (HIPed samples it could be concluded that the mechanical properties were mainly governed by the Fe-rich particles, which were fracturing through cleavage, not by the porosity.

  8. Making High-Tensile-Strength Amalgam Components

    Science.gov (United States)

    Grugel, Richard

    2008-01-01

    Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams

  9. Fuels and materials research under the high neutron fluence using a fast reactor Joyo and post-irradiation examination facilities

    International Nuclear Information System (INIS)

    Soga, Tomonori; Ito, Chikara; Aoyama, Takafumi; Suzuki, Soju

    2009-01-01

    The experimental fast reactor Joyo at Oarai Research and Development Center (ORDC) of Japan Atomic Energy Agency (JAEA) is Japan's sodium-cooled fast reactor (FR). In 2003, this reactor's upgrade to the 140MWt MK-III core was completed to increase the irradiation testing capability. The MK-III core provides the fast neutron flux of 4.0x10 15 n/cm 2 s as an irradiation test bed for improving the fuels and material of FR in Japan. Three post-irradiation examination (PIE) facilities named FMF, MMF and AGF related to Joyo are in ORDC. Irradiated subassemblies and core components are carried into the FMF (Fuel Monitoring Facility) and conducted nondestructive examinations. Each subassembly is disassembled to conduct some destructive examinations and to prepare the fuel and material samples for further detailed examinations. Fuel samples are sent to the AGF (Alpha-Gamma Facility), and material samples are sent to the MMF (Materials Monitoring Facility). These overall and elaborate data provided by PIE contribute to investigate the irradiation effect and behavior of fuels and materials. This facility complex is indispensable to promote the R and D of FR in Japan. And, the function and technology of irradiation test and PIE enable to contribute to the R and D of innovative fission or fusion reactor material which will be required to use under the high neutron exposure. (author)

  10. Dynamic strain aging of twinning-induced plasticity (TWIP) steel in tensile testing and deep drawing

    International Nuclear Information System (INIS)

    Kim, J.G.; Hong, S.; Anjabin, N.; Park, B.H.; Kim, S.K.; Chin, K.-G.; Lee, S.; Kim, H.S.

    2015-01-01

    The dynamic strain aging (DSA) of metallic materials due to solute atom diffusion to mobile dislocations induce deformation instability with load fluctuations and deformation localizations, hence reducing their sheet formability. In this paper, DSA behaviors of twinning induced plasticity (TWIP) steel with and without Al during tensile testing and deep drawing are investigated in terms of strain localization and the Portevin-Le Chatelier (PLC) band. A theoretical DSA model with internal variables of dislocation density and twin volume fraction is presented for an estimation of strain localization and strain hardening behavior of TWIP steels. The simulation results of the load history and PLC bands during tensile testing and deep drawing are in good agreement with the experimental values. A serration behavior is observed in high-Mn TWIP steels and its tensile residual stress is higher than that in the Al-added TWIP steels, which results in a deformation crack or delayed fracture of deep drawn specimens

  11. Tensile cracks in creeping solids

    International Nuclear Information System (INIS)

    Riedel, H.; Rice, J.R.

    1979-02-01

    The loading parameter determining the stress and strain fields near a crack tip, and thereby the growth of the crack, under creep conditions is discussed. Relevant loading parameters considered are the stress intensity factor K/sub I/, the path-independent integral C*, and the net section stress sigma/sub net/. The material behavior is modelled as elastic-nonlinear viscous where the nonlinear term describes power law creep. At the time t = 0 load is applied to the cracked specimen, and in the first instant the stress distribution is elastic. Subsequently, creep deformation relaxes the initial stress concentration at the crack tip, and creep strains develop rapidly near the crack tip. These processes may be analytically described by self-similar solutions for short times t. Small scale yielding may be defined. In creep problems, this means that elastic strains dominate almost everywhere except in a small creep zone which grows around the crack tip. If crack growth ensues while the creep zone is still small compared with the crack length and the specimen size, the stress intensity factor governs crack growth behavior. If the calculated creep zone becomes larger than the specimen size, the stresses become finally time-independent and the elastic strain rates can be neglected. In this case, the stress field is the same as in the fully-plastic limit of power law hardening plasticity. The loading parameter which determines the near tip fields uniquely is then the path-independent integral C*.K/sub I/ and C* characterize opposite limiting cases. The case applied in a given situation is decided by comparing the creep zone size with the specimen size and the crack length. Besides several methods of estimating the creep zone size, a convenient expression for a characteristic time is derived, which characterizes the transition from small scale yielding to extensive creep of the whole specimen

  12. Developing of tensile property database system

    International Nuclear Information System (INIS)

    Park, S. J.; Kim, D. H.; Jeon, J.; Ryu, W. S.

    2002-01-01

    The data base construction using the data produced from tensile experiment can increase the application of test results. Also, we can get the basic data ease from database when we prepare the new experiment and can produce high quality result by compare the previous data. The development part must be analysis and design more specific to construct the database and after that, we can offer the best quality to customers various requirements. In this thesis, the tensile database system was developed by internet method using JSP(Java Server pages) tool

  13. Nondestructive post-irradiation examination of Loop-1, S1 and B1 rods

    International Nuclear Information System (INIS)

    Bratton, R.L.

    1997-05-01

    As a part of the Pacific Northwest National Laboratory's Tritium Target Development Program, eleven tritium target rods were irradiated in the Advanced Test Reactor located at the Idaho National Engineering and Environmental Laboratory during 1991. Both nondestructive and destructive post-irradiation examination on all eleven rods was planned under the Tritium Target Development Program. Funding for the program was reduced in 1991 resulting in the early removal of the program experiments before reaching their irradiation goals. Post-irradiation examination was only performed on one of the irradiated rods at the Pacific Northwest National Laboratory before the program was terminated in 1992. On December 6, 1995, the Secretary of Energy announced the pursuit of the Commercial Light-Water Reactor option for producing tritium establishing the Tritium Target Qualification Program at the Pacific Northwest National Laboratory. This program decided to pursue nondestructive and destructive post-irradiation examination of the ten remaining rods from the previous program. The ten rods comprise three experiments. The Loop-1 experiment irradiated eight target rods in a loop configuration for 217 irradiation days. The other two rods were irradiated in two separate irradiation experiments, designated as S1 and B1 for 143 effective full-power days, but at different power levels. After the ten rods were transferred from the ATR Canal to the Hot Fuels Examination Facility, the following examinations were performed: (1) visual examination and photography; (2) neutron radiography; (3) axial gamma scanning; (4) contact profilometry measurement; (5) bow and length measurements; (6) rod puncture and plenum gas analysis/measurement of plenum gas quantity; (7) void volume determination; and (8) internal pressure determination. This report presents the data collected during these examinations

  14. Surface orientation effects on bending properties of surgical mesh are independent of tensile properties.

    Science.gov (United States)

    Simon, David D; Andrews, Sharon M; Robinson-Zeigler, Rebecca; Valdes, Thelma; Woods, Terry O

    2018-02-01

    Current mechanical testing of surgical mesh focuses primarily on tensile properties even though implanted devices are not subjected to pure tensile loads. Our objective was to determine the flexural (bending) properties of surgical mesh and determine if they correlate with mesh tensile properties. The flexural rigidity values of 11 different surgical mesh designs were determined along three textile directions (machine, cross-machine, and 45° to machine; n = 5 for each) using ASTM D1388-14 while tracking surface orientation. Tensile testing was also performed on the same specimens using ASTM D882-12. Linear regressions were performed to compare mesh flexural rigidity to mesh thickness, areal mass density, filament diameter, ultimate tensile strength, and maximum extension. Of 33 mesh specimen groups, 30 had significant differences in flexural rigidity values when comparing surface orientations (top and bottom). Flexural rigidity and mesh tensile properties also varied with textile direction (machine and cross-machine). There was no strong correlation between the flexural and tensile properties, with mesh thickness having the best overall correlation with flexural rigidity. Currently, surface orientation is not indicated on marketed surgical mesh, and a single mesh may behave differently depending on the direction of loading. The lack of correlation between flexural stiffness and tensile properties indicates the need to examine mesh bending stiffness to provide a more comprehensive understanding of surgical mesh mechanical behaviors. Further investigation is needed to determine if these flexural properties result in the surgical mesh behaving mechanically different depending on implantation direction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 854-862, 2018. © 2017 Wiley Periodicals, Inc.

  15. Mitigating IASCC of Reactor Core Internals by Post-Irradiation Annealing

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-06-02

    This final report summarizes research performed during the period between September 2012 and December 2016, with the objective of establishing the effectiveness of post-irradiation annealing (PIA) as an advanced mitigation strategy for irradiation-assisted stress corrosion cracking (IASCC). This was completed by using irradiated 304SS control blade material to conduct crack initiation and crack growth rate (CGR) experiments in simulated BWR environment. The mechanism by which PIA affects IASCC susceptibility will also be verified. The success of this project will provide a foundation for the use of PIA as a mitigation strategy for core internal components in commercial reactors.

  16. 16-rod-bundle: Irradiation in the MZFR and post-irradiation examinations

    International Nuclear Information System (INIS)

    Manzel, R.

    1979-04-01

    In the course of the irradiation of a 16-rod prototype bundle, the basis has been established for the irradiation of experimental fuel assemblies containing full-length PWR fuel rods in standard positions of the MZFR. The prototype bundle was discharged after an irradiation time of 284 full power days and a burnup of 11400 MWd/tU. The overall performance of the prototype bundle was highly satisfactory. Detailed post-irradiation examinations confirmed the good conditions of bundle structures and fuel rods. (orig.) [de

  17. Mitigating IASCC of Reactor Core Internals by Post-Irradiation Annealing

    International Nuclear Information System (INIS)

    Was, Gary

    2017-01-01

    This final report summarizes research performed during the period between September 2012 and December 2016, with the objective of establishing the effectiveness of post-irradiation annealing (PIA) as an advanced mitigation strategy for irradiation-assisted stress corrosion cracking (IASCC). This was completed by using irradiated 304SS control blade material to conduct crack initiation and crack growth rate (CGR) experiments in simulated BWR environment. The mechanism by which PIA affects IASCC susceptibility will also be verified. The success of this project will provide a foundation for the use of PIA as a mitigation strategy for core internal components in commercial reactors.

  18. Post-irradiation treatment of human lymphocytes with spermidine reduced frequency of chromatid breaks

    International Nuclear Information System (INIS)

    Bocian, E.; Rosiek, O.; Ziemba-Zoltowska, B.

    1978-01-01

    Human lymphocyte cultures were X-irradiated with a single dose of 100 or 200 rad 46 h after phytohemagglutinin stimulation. In dose-fractionation experiments, 2h later the second dose was applied. All the cultures were harvested at 54 h after their initiation. In lymphocytes irradiated with a single dose of 200 rad, 2h post-irradiation contact with 10 -5 M exogeneous spermidine resulted in reduction of chromatid breaks by 34 %. Introduction of spermidine into culture medium for fractionation interval between the 2 doses of 100 rad reduced the frequency of chromatid breaks by 42 %. (author)

  19. The growth of intra-granular bubbles in post-irradiation annealed UO2 fuel

    International Nuclear Information System (INIS)

    White, R.J.

    2001-01-01

    Post-irradiation examinations of low temperature irradiated UO 2 reveal large numbers of very small intra-granular bubbles, typically of around 1 nm diameter. During high temperature reactor transients these bubbles act as sinks for fission gas atoms and vacancies and can give rise to large volumetric swellings, sometimes of the order of 10%. Under irradiation conditions, the nucleation and growth of these bubbles is determined by a balance between irradiation-induced nucleation, diffusional growth and an irradiation induced re-solution mechanism. This conceptual picture is, however, incomplete because in the absence of irradiation the model predicts that the bubble population present from the pre-irradiation would act as the dominant sink for fission gas atoms resulting in large intra-granular swellings and little or no fission gas release. In practice, large fission gas releases are observed from post-irradiation annealed fuel. A recent series of experiments addressed the issue of fission gas release and swelling in post-irradiation annealed UO 2 originating from Advanced Gas Cooled Reactor (AGR) fuel which had been ramp tested in the Halden Test reactor. Specimens of fuel were subjected to transient heating at ramp rates of 0.5 deg. C/s and 20 deg. C/s to target temperatures between 1600 deg. C and 1900 deg. C. The release of fission gas was monitored during the tests. Subsequently, the fuel was subjected to post-irradiation examination involving detailed Scanning Electron Microscopy (SEM) analysis. Bubble-size distributions were obtained from seventeen specimens, which entailed the measurement of nearly 26,000 intra-granular bubbles. The analysis reveals that the bubble densities remain approximately invariant during the anneals and the bubble-size distributions exhibit long exponential tails in which the largest bubbles are present in concentrations of 10 4 or 10 5 lower than the concentrations of the average sized bubbles. Detailed modelling of the bubble

  20. Effect of medium and post-irradiation storage on rooting of irradiated onions

    International Nuclear Information System (INIS)

    Singh, Rita

    2000-01-01

    Rooting test for detection of irradiation in onion bulbs was studied. Onions were exposed to different dose levels of 30, 60, 90, 120 and 150 Gy. The effects of irradiation dose, cultivar difference, rooting medium and post-irradiation storage on the rooting were investigated. The number and the length of the roots formed in onions were found to decrease on irradiation. The effect was more at higher doses. The effect of irradiation on rooting was also evident after 120 days of storage. (author)

  1. New radiation mitigators to reduce bone marrow death of mice by post-irradiation administration

    International Nuclear Information System (INIS)

    Anzai, Kazunori

    2009-01-01

    We have found recently that heat-treated mineral yeast preparations and water-soluble analogs of vitamin E are potent radiation mitigator to reduce bone marrow death of mice by post-irradiation administration. When administered immediately after whole-body X-irradiation (7.5 Gy), both Zn-yeast and γ-tocopherol dimethylglycine ester (TDMG) significantly increased the viability of mice from 0% (control) to more than 90% (treated). Zn-yeast did not inhibit the tumor-regulation by γ-rays but even sensitize the radiation effect in mice xenografts of HeLa cells. (author)

  2. Facilities for post-irradiation examination of experimental fuel elements at Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Mizzan, E.; Chenier, R.J.

    1979-10-01

    Expansion of post-irradiation facilities at the Chalk River Nuclear Laboratories and steady improvement in hot-cell techniques and equipment are providing more support to Canada's reactor fuel development program. The hot-cell facility primarily used for examination of experimental fuels averages a quarterly throughput of 40 elements and 110 metallographic specimens. New developments in ultrasonic testing, metallographic sample preparation, active storage, active waste filtration, and fissile accountability are coming into use to increase the efficiency and safety of hot-cell operations. (author)

  3. Effect of 4-hydroxypyrazolo (3,4-d) pyrimidine (allopurinol) on postirradiation cerebral blood flow: implications of free radical involvement

    International Nuclear Information System (INIS)

    Cockerham, L.G.; Arroyo, C.M.; Hampton, J.D.

    1988-01-01

    In an attempt to elucidate mechanisms underlying the irradiation-induced decrease in regional cerebral blood flow (rCBF) in primates, hippocampal and hypothalamic blood flows of rhesus monkeys were measured by hydrogen clearance, before and after exposure to 100 Gy, whole body, gamma irradiation. Systemic blood pressures were monitored simultaneously. Compared to control animals, the irradiated monkeys exhibited an abrupt decline in systemic blood pressure to 35% of the preirradiation level within 10 min postirradiation, falling to 12% by 60 min. A decrease in hippocampal blood flow to 32% of the preirradiation level was noted at 10 min postirradiation, followed by a slight recovery to 43% at 30 min and a decline to 23% by 60 min. The hypothalamic blood flow of the same animals showed a steady decrease to 43% of the preirradiation levels by 60 min postirradiation. The postradiation systemic blood pressure of the allopurinol treated monkeys was not statistically different from the untreated, irradiated monkeys and was statistically different from the control monkeys. However, the treated, irradiated monkeys displayed rCBF values that were not significantly different from the nonirradiated controls. These findings suggest the involvement of free radicals in the postirradiation decrease in regional cerebral blood flow but not necessarily in the postirradiation hypotension seen in the primate

  4. Tensile and shear strength of adhesives

    Science.gov (United States)

    Stibolt, Kenneth A.

    1990-01-01

    This experiment is conducted in a freshman-level course: Introduction to Engineering Materials. There are no prerequisites for the course although students should have some knowledge of basic algebra. The objectives are to tension and shear test adhesives and to determine the tensile and shear properties of adhesives. Details of equipment of procedure are given.

  5. 7 CFR 29.3061 - Strength (tensile).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength (tensile). 29.3061 Section 29.3061 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official...

  6. 7 CFR 29.6040 - Strength (tensile).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength (tensile). 29.6040 Section 29.6040 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Definitions §...

  7. Tensile Strength of the Eggshell Membranes

    Czech Academy of Sciences Publication Activity Database

    Strnková, J.; Nedomová, Š.; Kumbár, V.; Trnka, Jan

    2016-01-01

    Roč. 64, č. 1 (2016), s. 159-164 ISSN 1211-8516 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : eggshell membrane * tesile test * loading rate * tensile strength * fracture strain Subject RIV: GM - Food Processing

  8. Evaluation of ring tensile test results

    International Nuclear Information System (INIS)

    Chatterjee, S.; Anantharaman, S.; Balakrishnan, K.S.; Sivaramakrish, K.S.

    1990-01-01

    Ring specimens of 5-mm width cut from Zircaloy-2 cladding of reactor operated fuel elements that had experienced 5000 to 15,000 MWD/T of fuel burnup were subjected to ring tensile testing. The true stress-true strain data points up to the onset of necking from the individual load-elongation curves of these specimens were used as input data in Voce's equation. The results reveal that the uniform elongation (UE) values generated using Voce's equation were within (UE-2)% of the experimental percent uniform elongation (UE%). The corresponding ultimate tensile strength values were within ±1%. The uncertainty inherently associated in the determination of gauge length introduces extraneous deformation in the rings tested. Previous results had shown that a 14% increase in cladding diameter caused the gauge length to increase by 40%. To simulate the contribution of extraneous deformation due to an increase in cladding diameter, an analysis of the variation of the tensile parameters (uniform elongation and ultimate tensile strength) due to increase in the gauge length in the range of 10 to 40% was carried out. The results are discussed

  9. The effect of grain size on dynamic tensile extrusion behaviour

    Directory of Open Access Journals (Sweden)

    Park Leeju

    2015-01-01

    Full Text Available Dynamic tensile extrusion (DTE tests were conducted on coarse grained and ultrafine grained (UFG OFHC Cu, Interstitial free (IF Steel, and pure Ta. Equal channel angular pressing (ECAP of 16passes with Bc for Cu, IF Steel and 4 passes for Ta was employed to fabricated UFG materials. DTE tests were carried out by launching the sphere samples (Dia. 7.62 mm to the conical extrusion die at a speed of ∼500 m/sec. The fragmentation behavior of the soft-recovered fragments were examined and compared with each other. The DTE fragmentation behavior of CG and UFG was numerically simulated by the LS-DYNA FEM code.

  10. The study on the threshold strain of microvoid formation in TRIP steels during tensile deformation

    International Nuclear Information System (INIS)

    Wang Wurong; Guo Bimeng; Ji Yurong; He Changwei; Wei Xicheng

    2012-01-01

    Highlights: ► The tensile mechanical behaviors of TRIP steels were studied under high rate deformation conditions. ► The threshold strain of microvoid formation was examined quantitatively. ► The effects of retained austenite of TRIP on suppressing microvoid formed during tensile process have been discussed. - Abstract: Transformation Induced Plasticity (TRIP) steels exhibit a better combination of strength and ductility properties than conventional high strength low alloy (HSLA) steels, and therefore receive considerable attention in the automotive industry. In this work, the tensile mechanical behaviors of TRIP-aided steels were studied under the condition of the quasi-static and high deformed rates. The deformed specimens were observed by scanning electron microscope (SEM) along the tensile axis. The threshold strain of microvoid formation was examined quantitatively according to the evolution of deformation. The results showed that: the yield and tensile strengths of TRIP steels increase with the strain rate, whereas their elongations decrease. However, the threshold strain for TRIP steels at high strain rate is larger than that at low strain rate. Comparing with the deformed microstructure and microvoids formed in the necking zone of dual phase (DP) steel, the progressive deformation-induced transformation of retained austenite in TRIP steels remarkably increases the threshold strain of microvoid formation and furthermore postpones its growth and coalescence.

  11. The post-irradiated examination of CANDU type fuel irradiated in the Institute for Nuclear Research TRIGA reactor

    International Nuclear Information System (INIS)

    Tuturici, I.L.; Parvan, M.; Dobrin, R.; Popov, M.; Radulescu, R.; Toma, V.

    1995-01-01

    This post-irradiation examination work has been done under the Research Contract No. 7756/RB, concluded between the International Atomic Energy Agency and the Institute for Nuclear Research. The paper contains a general description of the INR post-irradiation facility and methods and the relevant post-irradiation examination results obtained from an irradiated experimental CANDU type fuel element designed, manufactured and tested by INR in a power ramp test in the 100 kW Pressurised Water Irradiation Loop of the TRIGA 14 MW(th) Reactor. The irradiation experiment consisted in testing an assembly of six fuel elements, designed to reach a bumup of ∼ 200 MWh/kgU, with typical CANDU linear power and ramp rate. (author)

  12. A study on fatigue crack growth behavior subjected to a single tensile overload: Part II. Transfer of stress concentration and its role in overload-induced transient crack growth

    International Nuclear Information System (INIS)

    Lee, S.Y.; Choo, H.; Liaw, P.K.; An, K.; Hubbard, C.R.

    2011-01-01

    The combined effects of overload-induced enlarged compressive residual stresses and crack tip blunting with secondary cracks are suggested to be responsible for the observed changes in the crack opening load and resultant post-overload transient crack growth behavior [Lee SY, Liaw PK, Choo H, Rogge RB, Acta Mater 2010;59:485-94]. In this article, in situ neutron diffraction experiments were performed to quantify the influence of the combined effects by investigating the internal-stress evolution at various locations away from the crack tip. In the overload-retardation period, stress concentration occurs in the crack blunting region (an overload point) until a maximum crack arrest load is reached. The stress concentration is then transferred from the blunting region to the propagating crack tip (following the overload), requiring a higher applied load, as the closed crack is gradually opened. The transfer phenomena of the stress concentration associated with a crack opening process account for the nonlinearity of strain response in the vicinity of the crack tip. The delaying action of stress concentration at the crack tip is understood in conjunction with the concept of a critical stress (i.e. the stress required to open the closed crack behind the crack tip). A linear relationship between Δε eff and ΔK eff provides experimental support for the hypothesis that ΔK eff can be considered as the fatigue crack tip driving force.

  13. Effects of drugs inhibiting prostaglandin or leukotriene biosynthesis on postirradiation haematopoiesis in mouse

    International Nuclear Information System (INIS)

    Kozubik, A.; Hofmanova, J.; Pospisil, M.; Netikova, J.; Hola, J.; Lojek, A.

    1994-01-01

    Two non-steroidal anti-inflammatory drugs, i.e. indomethacin (INDO), an inhibitor of prostaglandin production, and esculetin (ESCUL), an inhibitor of leukotriene production, were tested for their ability to modify haematopoiesis in three experimental systems: (a) in vitro clonal proliferation of marrow GM-CFC from the irradiated mouse was found to be augmented by addition of INDO at a low concentration, and inhibited by ESCUL in a dose-dependent manner; (b) in the lethally irradiated and bone marrow-transplanted mice treated with the drugs in the postirradiation period, stimulatory effects of INDO on CFU-S and GM-CFC populations and an inhibitory effect of ESCUL on GM-CFC were observed; and (c) when the drugs were administered i.p. to mice 1 h before 5-Gy irradiation, INDO enhanced the postirradiation recovery of haematopoietic indices such the numbers of CFU-S, GM-CFC, peripheral blood granuloctyes, and nucleated bone marrow cells, while ESCUL had no effect or even inhibited the recovery of these indices. (author)

  14. The effect of PGE2, gastrin and CCK-8 on postirradiation recovery of small intestine epithelium

    International Nuclear Information System (INIS)

    Dziekiewicz, M.; Chomiczewski, K.; Jablonska, H.

    1997-01-01

    The role of some natural factors in the postirradiation recovery of intestinal epithelium is a very interesting and inscrutable problem. In our experiment the comparative effect of PGE 2 , Gastrin and CCK-8 fragment of Cholecystokinin on this problem has been investigated. Male Swiss PZH mice 8 weeks old were irradiated to the whole body with a dose of 5.5 Gy and to abdomen with a dose of 12 Gy of gamma rays. The first experimental group received PGE 2 before 30 min. irradiation, the second received Gastrin after irradiation during 5 days, the third was injected with CCK-8 after irradiation during 5 days too. Unirradiated and only irradiated animals served as control groups. Survival of 30 mice in every group was registered during 30 days after irradiation. The another part of animals in every group were killed between 1 and 12 days after irradiation. Changes in the body weight were registered. Using computer image analysis system , some histological slides were examined, adding the statistical analysis of results. The preliminary results suggest that all those factors are able to stimulate the postirradiation regeneration of small intestinal epithelium (author)

  15. Postirradiation recovery of a reactor pressure vessel steel investigated by positron annihilation and microhardness measurements

    International Nuclear Information System (INIS)

    Pareja, R.; Diego, N. De; Cruz, R.M. de la; Del Rio, J.

    1993-01-01

    Positron lifetime and microhardness measurements have been performed on untreated, thermal-aged, neutron-irradiated, and postirradiation-annealed samples of reactor pressure vessel steels with the purpose of investigating the mechanisms of irradiation-induced hardening and recovery of the mechanical properties in these materials. The positron lifetime experiments have not revealed any evidence of the formation of a significant concentration of voids or vacancy clusters in samples irradiated at ∼290 C with fluences ≤2.71 x 10 23 n/m 2 (E>1 MeV), but they suggest a dislocation annealing induced by the irradiation. Isochronal annealing experiments with neutron-irradiated samples show a simultaneous recovery in their positron lifetime and microhardness at ∼340 C. From the microhardness measurements, the yield strength of the irradiated material has been estimated. The results appear to be consistent with a model of hardening due to irradiation-induced dissolution of precipitates with formation of small metastable precipitates after postirradiation aging and recovery induced by the disappearance of these metastable precipitates

  16. Surgical treatments for post-irradiation intestinal injury in uterine cervix cancer patients

    International Nuclear Information System (INIS)

    Nozaki, Isao; Yokoyama, Nobuji; Takashima, Shigemitsu

    1997-01-01

    We examined 19 patients with post-irradiation intestinal injury in the uterine cervix cancer for 12 years between 1985 and 1996. We discuss the usefulness and complications of surgery, mainly colostomy. The patients aged from 36 to 80 (average age 61) were treated, and their disease states were 12 cases of rectovaginal fistula, 2 of small intestinal fisfula, 1 of rectum posterior membranous fistula, 3 of proctostenosis, and 14 of proctitis with hemorrhage (including duplication). Surgical methods used were 18 cases of colostomy (2 cases were treated under peritoneum mirror) and 2 of enterocolostomy (including duplication). Eleven out of 19 patients who underwent surgery are alive now. Generally the post-irradiation intestinal injury was intractable, and the method of treatments were limited due to the coexistence of various diseases. The colostomy is safe and less invasive. Therefore patients with uterine cervix cancer having various complications can obtain high quality of life (QOL) such as the improvement of anemia and/or the increase of digestion by the colostomy. (K.H.)

  17. Surgical treatments for post-irradiation intestinal injury in uterine cervix cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Nozaki, Isao; Yokoyama, Nobuji; Takashima, Shigemitsu [National Shikoku Cancer Center Hospital, Matsuyama, Ehime (Japan)

    1997-06-01

    We examined 19 patients with post-irradiation intestinal injury in the uterine cervix cancer for 12 years between 1985 and 1996. We discuss the usefulness and complications of surgery, mainly colostomy. The patients aged from 36 to 80 (average age 61) were treated, and their disease states were 12 cases of rectovaginal fistula, 2 of small intestinal fisfula, 1 of rectum posterior membranous fistula, 3 of proctostenosis, and 14 of proctitis with hemorrhage (including duplication). Surgical methods used were 18 cases of colostomy (2 cases were treated under peritoneum mirror) and 2 of enterocolostomy (including duplication). Eleven out of 19 patients who underwent surgery are alive now. Generally the post-irradiation intestinal injury was intractable, and the method of treatments were limited due to the coexistence of various diseases. The colostomy is safe and less invasive. Therefore patients with uterine cervix cancer having various complications can obtain high quality of life (QOL) such as the improvement of anemia and/or the increase of digestion by the colostomy. (K.H.)

  18. In vivo postirradiation protection by a vitamin E analog, alpha-TMG.

    Science.gov (United States)

    Satyamitra, Merriline; Uma Devi, P; Murase, Hironobu; Kagiya, V T

    2003-12-01

    The water-soluble vitamin E derivative alpha-TMG is an excellent radical scavenger. A dose of 600 mg/kg TMG significantly reduced radiation clastogenicity in mouse bone marrow when administered after irradiation. The present study was aimed at investigating the radioprotective effect of postirradiation treatment with alpha-TMG against a range of whole-body lethal (8.5-12 Gy) and sublethal (1-5 Gy) doses of radiation in adult Swiss albino mice. Protection against lethal irradiation was evaluated from 30-day mouse survival and against sublethal doses was assessed from micronuclei and chromosomal aberrations in the bone marrow 24 h after irradiation. An intraperitoneal injection of 600 mg/kg TMG within 10 min of lethal irradiation increased survival, giving a dose modification factor (DMF) of 1.09. TMG at doses of 400 mg/kg and 600 mg/kg significantly reduced the percentage of aberrant metaphases, the different types of aberrations, and the number of micronucleated erythrocytes. DMFs of 1.22 and 1.48 for percentage aberrant metaphases and 1.6 and 1.98 for micronuclei were obtained for 400 mg/kg and 600 mg/kg TMG, respectively. No drug toxicity was observed at these doses. The effectiveness of TMG when administered postirradiation suggests its possible utility for protection against unplanned radiation exposures.

  19. A case of postirradiation angiosarcoma developed in the residual breast after breast-conserving surgery

    International Nuclear Information System (INIS)

    Nomura, Shinji; Okazaki, Yoshikazu; Fujii, Masakazu; Akiyama, Norio; Tomozawa, Naofumi; Morishige, Ichiro

    2008-01-01

    The patient was a 50-year-old woman who had undergone breast-conserving surgery for right breast cancer (C area, Bp+Ax, T2N0M0, Stage I, and scirrhous carcinoma), followed by irradiation at a total dose of 50 Gy in 1998. When 6 years 5 months had elapsed after the operation, redness and induration developed in the A area of the right breast. A biopsy via wedge resection was performed and the histopathological diagnosis was angiosarcoma. We could not rule out a possibility of positive surgical stump, and performed additional resection+skin grafting. No sarcoma remnant was demonstrated in the material resected additionally, but 2 years later, the patient experienced recurrence. Thus mastectomy+extended resection of the full thickness of the skin+skin grafting were performed. Postirradiation sarcoma involving the skin and vessels is a rare entity and occurs in 0.03-0.8% of all cases after radiation therapy. It metastasizes to the distant organs in an early stage and carries poor prognosis. No standard therapy for the disease has been established as yet. Early detection and extended resection are considered to contribute to an improvement of the prognosis. This paper deals with such a rare entity as postirradiation angiosarcoma developed in the residual breast after breast-conserving surgery. (author)

  20. Irradiation of Argentine MOX fuels: Post-irradiation results and analysis

    International Nuclear Information System (INIS)

    Marino, A.C.; Perez, E.; Adelfang, P.

    1997-01-01

    The irradiation of the first Argentine prototypes of PHWR MOX fuels began in 1986. These experiments were made in the HFR-Petten reactor, Holland. The rods were prepared and controlled in the CNEA's facility. The postirradiation examinations were performed in the Kernforschungszentrum, Karlsruhe, Germany and in the JRC, Petten. The first rod has been used for destructive pre-irradiation analysis. The second one as a pathfinder to adjust systems in the HFR. Two additional rods including iodine doped pellets were intended to simulate 15000 MWd/T(M) burnup. The remaining two rods were irradiated until 15000 MWd/T(M) (BU15 experiment). One of them underwent a final ramp with the aim of verifying fabrication processes and studying the behaviour under power transients. BACO code was used to define the power histories and to analyze the experiments. This paper presents the postirradiation examinations for the BU15 experiments and a comparison with the BACO outputs for the rod that presented a failure during the ramp test of the BU15 experiment. (author). 17 refs, 30 figs, 5 tabs

  1. AGR-1 Compact 5-3-1 Post-Irradiation Examination Results

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Phil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ploger, Scott A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance, and fission product transport (INL 2015). A series of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously.

  2. Effects of drugs inhibiting prostaglandin or leukotriene biosynthesis on postirradiation haematopoiesis in mouse

    Energy Technology Data Exchange (ETDEWEB)

    Kozubik, A.; Hofmanova, J.; Pospisil, M.; Netikova, J.; Hola, J.; Lojek, A. (Ceskoslovenska Akademie Ved, Brno (Czech Republic). Biofysikalni Ustav)

    1994-03-01

    Two non-steroidal anti-inflammatory drugs, i.e. indomethacin (INDO), an inhibitor of prostaglandin production, and esculetin (ESCUL), an inhibitor of leukotriene production, were tested for their ability to modify haematopoiesis in three experimental systems: (a) in vitro clonal proliferation of marrow GM-CFC from the irradiated mouse was found to be augmented by addition of INDO at a low concentration, and inhibited by ESCUL in a dose-dependent manner; (b) in the lethally irradiated and bone marrow-transplanted mice treated with the drugs in the postirradiation period, stimulatory effects of INDO on CFU-S and GM-CFC populations and an inhibitory effect of ESCUL on GM-CFC were observed; and (c) when the drugs were administered i.p. to mice 1 h before 5-Gy irradiation, INDO enhanced the postirradiation recovery of haematopoietic indices such the numbers of CFU-S, GM-CFC, peripheral blood granuloctyes, and nucleated bone marrow cells, while ESCUL had no effect or even inhibited the recovery of these indices. (author).

  3. Post-irradiation pericardial malignant mesothelioma with deletion of p16: a case report.

    Science.gov (United States)

    Naeini, Yalda B; Arcega, Ramir; Hirschowitz, Sharon; Rao, Nagesh; Xu, Haodong

    2018-02-01

    Malignant mesotheliomas are rather uncommon neoplasms associated primarily with asbestos exposure; however, they may also arise as second primary malignancies after radiation therapy, with a latency period of 15-25 years. Numerous studies have reported an association between pleural malignant mesothelioma and chest radiation performed for other malignancies; on the other hand, post-irradiation mesotheliomas of the pericardium have been reported in only a few published cases to date, and no homozygous deletion of 9p21 has been described in such cases. We report the case of a 48-year-old man with a history of Hodgkin's lymphoma and no prior asbestos exposure who developed pericardial malignant epithelioid mesothelioma. We further discuss the cytologic, histologic, immunophenotypic, and fluorescence in situ hybridization findings in this case. To our knowledge, this is the first well-documented case of post-radiation pericardial malignant mesothelioma showing homozygous deletion of 9p21. Homozygous deletion of 9p21, the locus harboring the p16 gene, is present in post-irradiation pericardial malignant mesothelioma.

  4. Time-dependent postirradiation oxidative chemical changes in dehydrated egg products

    International Nuclear Information System (INIS)

    Katusin-Razem, B.; Mihaljevic, B.; Razem, D.

    1992-01-01

    Radiation-induced oxidative chemical changes in whole egg and egg yolk powder were followed in time after irradiation as a function of dose, dose rate, and storage atmosphere. In evacuated samples of whole egg powder the decay of lipid hydroperoxides (LOOH) was pseudo-first order (kappa = 0.088 day-1), while carotenoids did not decay at all. In the presence of air both lipid hydroperoxides and carotenoids decayed during postirradiation storage. The decay of LOOH could be treated by dispersive kinetics with the measure of dispersion, alpha = 0.51 +/- 0.05, independent of dose, and the effective lifetime tau inversely related to dose. The decay of carotenoids could also be treated by dispersive kinetics, with the values of alpha decreasing with increasing dose. The effective lifetimes of carotenoids did not depend on dose in samples irradiated in vacuum. In samples irradiated and stored in air the effective lifetimes decreased with dose, faster in egg yolk than in whole egg powder. The complex nature of postirradiation kinetics in solid food systems is discussed

  5. On the determination of the post-irradiation time from the glow curve of TLD-100

    International Nuclear Information System (INIS)

    Weinstein, M.; German, U.; Dubinsky, S.; Alfassi, Z.B.

    2003-01-01

    The ratio of peak 3 to the sum of peaks 4 + 5 in TLD-100 was measured for various pre-irradiation and post-irradiation time periods, under conditions characteristic of routine personal dosimetry. It was confirmed that the value of this ratio depends only on the elapsed time between the prior readout and the present one, independent of the moment when the irradiation took place during the total time interval (storage time). This effect indicates that fading of peak 3 seems to be due mainly to changes in the unoccupied traps, and not to decay of trapped charges, being almost independent of the presence of electrons or holes in the traps. This observation leads to the conclusion that the suggestions in the past to use the decay of peak 3 in TLD-100 for the measurement of the elapsed time between irradiation and readout may have been wrong. On the other hand, the decay of peak 2 can be used to measure the elapsed time from irradiation, since the rate of decay is different when related to pre-irradiation and post-irradiation times, indicating a much higher decay rate of the trapped charges (Randall-Wilkins decay). However, because of the fast decay rate of peak 2, its use for determination of the elapsed time since irradiation is of little practical significance. (author)

  6. Application of eddy currents to post-irradiation examination of fuel rods

    International Nuclear Information System (INIS)

    Domizzi, G.; Ruch, M.; Ruggirello, G.; Spinosa, C.

    1997-01-01

    Postirradiation tests are performed on the fuel bundles of nuclear power plants, in order to evaluate their performance. The Zircaloy-4 cladding, the first containment of the fission products, is a very important part of these bundles. A fundamental step of these tests is the in-pool identification of the failed bars in the 'suspect' bundles. Later, once in the hot cell facility and prior to the destructive tests, it is necessary to characterize the defects in the cladding. The eddy current method provides a means for fast and reliable detection and characterisation of defects unobservable in visual inspection, such as tiny cracks, pores and anomalously hydride regions. The project for the application of this method in postirradiation tests has been divided into three stages, namely laboratory set up, in-pool tests, hot-cell application, the first one being described here. Techniques for the construction of synthetic defects (machined, micro cracks, abnormal hydride concentration, hydride blisters, oxide layers) were developed. A mechanical device for automatic probe movement was designed and constructed. Special external probes for the particular defects were developed. The inspection procedure was prepared. (author) [es

  7. Water absorption and tensile strength degradation of Petung bamboo (Dendrocalamus asper) fiber-reinforced polymeric composites

    NARCIS (Netherlands)

    Judawisastra, H.; Sitohang, Ramona; Rosadi, M. S.

    2017-01-01

    Bamboo fibers have attracted great interest and are believed to have the potential as natural fiber for reinforcing polymer composites. This research aims to study water absorption behavior and its effect to tensile strength of the composites made from petung bamboo fiber, which is one of the most

  8. Tensile and dimensional properties of wood strands made from plantation southern pine lumber

    Science.gov (United States)

    Qinglin Wu; Zhiyong Cai; Jong N. Lee

    2005-01-01

    Working stresses and performance of strand composite lumber largely depend upon the properties of each individual strand. Southern pine strands from plantation lumber grown in southern Louisiana were investigated in this study in order to understand strand behaviors. The effects of hot-pressing and resin application on tensile modulus, strength, and dimensional...

  9. Analysis of the tensile behaviour of zircaloy-4 in the region of dynamic strain aging

    International Nuclear Information System (INIS)

    Dellaretti Filho, O.

    1974-01-01

    An analysis of the tensile behavior of Zircaloy 4, centering around the influence of dynamic strain aging and strain rate history, is presented. This analysis is based on techniques introduced by Jaoul-Crussard and Reed-Hill. An attempt is also made to assess the experimental errors that influence these methods. (author)

  10. Optimization of tensile method and specimen geometry in modified ring tensile test

    International Nuclear Information System (INIS)

    Kitano, Koji; Fuketa, Toyoshi; Sasajima, Hideo; Uetsuka, Hiroshi

    2001-03-01

    Several techniques in ring tensile test are proposed in order to evaluate mechanical properties of cladding under hoop loading condition caused by pellet/cladding mechanical interaction (PCMI). In the modified techniques, variety of tensile methods and specimen geometry are being proposed in order to limit deformation within the gauge section. However, the tensile method and the specimen geometry were not determined in the modified techniques. In the present study, we have investigated the tensile method and the specimen geometry through finite element method (FEM) analysis of specimen deformation and tensile test on specimens with various gauge section geometries. In using two-piece tensile tooling, the mechanical properties under hoop loading condition can be correctly evaluated when deformation part (gauge section) is put on the top of a half-mandrel, and friction between the specimen and the half-mandrel is reduced with Teflon tape. In addition, we have shown the optimum specimen geometry for PWR 17 by 17 type cladding. (author)

  11. Post-irradiation dietary vitamin E does not affect the development of radiation-induced lung damage in rats

    International Nuclear Information System (INIS)

    Wiegman, Erwin M.; Gameren, Mieke M. van; Kampinga, Harm H.; Szabo, Ben G.; Coppes, Rob P.

    2004-01-01

    The purpose of this study was to investigate whether application of post-irradiation vitamin E, an anti-oxidant, could prevent the development of radiation induced lung damage. Wistar rats were given vitamin E enriched or vitamin E deprived food starting from 4 weeks after 18 Gy single dose irradiation of the right thorax. Neither breathing frequencies nor CT density measurements revealed differences between the groups. It is concluded that post-irradiation vitamin E does not influence radiation-induced fibrosis to the lung

  12. Experimental assessments of notch ductility and tensile strength of stainless steel weldments after 1200C neutron irradiation

    International Nuclear Information System (INIS)

    Hawthorne, J.R.; Menke, B.H.; Awadalla, N.G.; O'Kula, K.R.

    1986-01-01

    The Charpy-V (C/sub v/) properties of AISI 300 series stainless steel plate, weld, and weld heat-affected zone (HAZ) materials from commercial production weldments in 406-mm-diameter pipe (12.7-mm wall) were investigated in unirradiated and irradiated conditions. Weld and HAZ tensile properties were also assessed in the two conditions. The plates and weld filler wires represent different steel melts; the welds were produced using the multipass MIG process. Weldment properties in two test orientations were evaluated. Specimens were irradiated in the UBR reactor to 1 x 10 20 n/cm 2 , E >0.1 MeV in a controlled temperature assembly. Specimen tests were performed at 25 0 C and 125 0 C. The radiation-induced reductions in C/sub v/ energy absorption at 25 0 C were about 42 percent for the weld and HAZ materials evaluated. A trend of energy increase with temperature was observed. The concomitant elevation in yield strength was about 53%. In contrast, the increase in tensile strength was only 16%. The postirradiation yield strength of the axial test orientation in the pipe was less than that of the circumferential test orientation. Results for the HAZ indicate that this component may be the weakest link in the weldment from a fracture resistant viewpoint

  13. Experimental assessments of notch ductility and tensile strength of stainless steel weldments after 1200C neutron irradiation

    International Nuclear Information System (INIS)

    Hawthorne, J.R.; Menke, B.H.; Awadalla, N.G.; O'Kula, K.R.

    1987-01-01

    The Charpy-V (C/sub V/) properties of American Iron and Steel Institute (AISI) 300 series stainless steel plate, weld, and weld heat-affected zone (HAZ) materials from commercial production weldments in 406-mm-diameter pipe (12.7-mm wall) were investigated in unirradiated and irradiated conditions. Weld and HAZ tensile properties were also assessed in the two conditions. The plates and weld filler wires represent different steel melts; the welds were produced using the multipass metal inert gas (MIG) process. Weldment properties in two test orientations were evaluated. Specimens were irradiated in a light water cooled and moderated reactor to 1 x 10/sup 20/ n/cm/sup 2/, E > 0.1 MeV, using a controlled temperature assembly. Specimen tests were performed at 25 and 125 0 C. The radiation-induced reductions in C/sub V/ energy absorption at 25 0 C were about 42% for the weld and the HAZ materials evaluated. A trend of energy increase with temperature was observed. The concomitant elevation in yield strength was about 53%. The increase in tensile strength in contrast was only 16%. The postirradiation yield strength of the axial test orientation in the pipe was less than that of the circumferential test orientation. Results for the HAZ indicate that this component may be the weakest link in the weldment from a fracture resistance viewpoint

  14. Analysis on the post-irradiation examination of the HANARO miniplate-1 irradiation test for Kijang research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Man; Tahk, Young Wook; Jeong, Yong Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); and others

    2017-08-15

    The construction project of the Kijang research reactor (KJRR), which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U–Mo fuel. Plate-type U–7 wt.% Mo/Al–5 wt.% Si, referred to as U–7Mo/Al–5Si, dispersion fuel with a uranium loading of 8.0 gU/cm{sup 3}, was selected to achieve higher fuel efficiency and performance than are possible when using U{sub 3}Si{sub 2}/Al dispersion fuel. To qualify the U–Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1)], containing U–7Mo/Al–5Si dispersion fuel (8 gU/cm{sup 3}), were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination) results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U–7Mo/Al–5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U–Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U–Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.

  15. Analysis on the post-irradiation examination of the HANARO miniplate-1 irradiation test for kijang research reactor

    Directory of Open Access Journals (Sweden)

    Jong Man Park

    2017-08-01

    Full Text Available The construction project of the Kijang research reactor (KJRR, which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U–Mo fuel. Plate-type U–7 wt.% Mo/Al–5 wt.% Si, referred to as U–7Mo/Al–5Si, dispersion fuel with a uranium loading of 8.0 gU/cm3, was selected to achieve higher fuel efficiency and performance than are possible when using U3Si2/Al dispersion fuel. To qualify the U–Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1], containing U–7Mo/Al–5Si dispersion fuel (8 gU/cm3, were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U–7Mo/Al–5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U–Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U–Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.

  16. Deformation features of aluminium in tensile tests

    International Nuclear Information System (INIS)

    Quadros, N.F. de.

    1984-01-01

    It is presented a method to analyse stress-strain curves. Plastic and elastic strains were studied. The strains were done by tensile tests in four types of materials: highly pure aluminium, pure aluminium, commercially pure aluminium and aluminium - uranium. The chemical compositions were obtained by spectroscopy analysis and neutron activation analysis. Tensile tests were carried out at three strain rates, at room temperature, 100,200, 300 and 400 0 C, with knives extensometer and strain-gages to studied the elastic strain region. A multiple spring model based on two springs model to analyse elastic strain caused by tests without extensometers, taking in account moduli of elasticity and, an interactive analysis system with graphic capability were developed. It was suggested a qualitative model to explain the quantized multielasticity of Bell. (M.C.K.) [pt

  17. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

    Science.gov (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

    2016-02-01

    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  18. Investigation of Tensile Creep of a Normal Strength Overlay Concrete.

    Science.gov (United States)

    Drexel, Martin; Theiner, Yvonne; Hofstetter, Günter

    2018-06-12

    The present contribution deals with the experimental investigation of the time-dependent behavior of a typical overlay concrete subjected to tensile stresses. The latter develop in concrete overlays, which are placed on existing concrete structures as a strengthening measure, due to the shrinkage of the young overlay concrete, which is restrained by the substrate concrete. Since the tensile stresses are reduced by creep, creep in tension is investigated on sealed and unsealed specimens, loaded at different concrete ages. The creep tests as well as the companion shrinkage tests are performed in a climatic chamber at constant temperature and constant relative humidity. Since shrinkage depends on the change of moisture content, the evolution of the mass water content is determined at the center of each specimen by means of an electrolytic resistivity-based system. Together with the experimental results for compressive creep from a previous study, a consistent set of time-dependent material data, determined for the same composition of the concrete mixture and on identical specimens, is now available. It consists of the hygral and mechanical properties, creep and shrinkage strains for both sealed and drying conditions, the respective compliance functions, and the mass water contents in sealed and unsealed, loaded and load-free specimens.

  19. Theory of the tensile actuation of fiber reinforced coiled muscles

    Science.gov (United States)

    Lamuta, C.; Messelot, S.; Tawfick, S.

    2018-05-01

    There is a strong need for compact artificial muscles capable of applying large contractile strokes and lift heavy weights. Coiled fibers recently emerged as attractive candidates for these purposes, owing to their simple construction and the possibility of their thermal, electrical and chemical actuation. An intuitive theoretical understanding of the mechanics of actuation of these muscles is essential for the enhancement of their performance and can pave the way for the development of new applications and technologies. In this paper, a complete theoretical model for the tensile actuation of fiber reinforced artificial muscles is presented and experimentally validated. The model demonstrates that all muscles made from the same material have a universal behavior, which can be described by a single master curve. It enables the systematic design and understanding of coiled muscles for specific performance owing to a comprehensive mathematical correlation among the geometry, materials properties, and actuation. Carbon fibers (CF)/polydimethylsiloxane coiled muscles are demonstrated as simple to fabricate yet powerful muscles owing to the availability of high strength CF. In addition to showing excellent agreement with the theoretical models, they can be actuated by joule heating or chemical swelling, lift up to 12 600 times their own weight, support up to 60 MPa of mechanical stress, provide tensile strokes higher than 25%, and a specific work up to 758 J kg‑1, the latter is more than 18 times higher than that of natural muscles.

  20. Cracking and Deformation Modelling of Tensile RC Members Using Stress Transfer Approach

    Directory of Open Access Journals (Sweden)

    Ronaldas Jakubovskis

    2016-12-01

    Full Text Available The paper presents a modeling technique for bond, cracking and deformation analysis of RC members. The proposed mod-eling technique is not restricted by the geometrical dimensions of the analyzed member and may be applied for various load-ing conditions. Tensile as well as bending RC members may be analyzed using the proposed technique. Adequacy of the modeling strategy was evaluated by the developed numerical discrete crack algorithm, which allows modeling deformation and cracking behavior of tensile RC members. Comparison of experimental and numerical results proved the applicability of the proposed modeling strategy.

  1. Tensile creep of beta phase zircaloy-2

    International Nuclear Information System (INIS)

    Burton, B.; Reynolds, G.L.; Barnes, J.P.

    1977-08-01

    The tensile creep and creep rupture properties of beta-phase zircaloy-2 are studied under vacuum in the temperature and stress range 1300-1550 K and 0.5-2 MN/m 2 . The new results are compared with previously reported uniaxial and biaxial data. A small but systematic difference is noted between the uniaxial and biaxial creep data and reasons for this discrepancy are discussed. (author)

  2. Environmental behaviour of tensile membrane structures

    OpenAIRE

    Elnokaly, Amira; Chilton, John; Wilson, Robin

    2002-01-01

    This paper considers the environmental properties of spaces enclosed by tensile membrane structures (TMS). Limitations in the understanding of the environmental and thermal performance of TMS have to some extent hindered their acceptance by building clients and the building industry. A review of the early attempts to model the thermal environment of spaces enclosed by TMS is given and their environmental and thermal properties are discussed. The lack of appropriate tools for the investigation...

  3. MISSE 6 Polymer Film Tensile Experiment

    Science.gov (United States)

    Miller, Sharon K. R.; Dever, Joyce A.; Banks, Bruce A.; Waters, Deborah L.; Sechkar, Edward; Kline, Sara

    2010-01-01

    The Polymer Film Tensile Experiment (PFTE) was flown as part of Materials International Space Station Experiment 6 (MISSE 6). The purpose of the experiment was to expose a variety of polymer films to the low Earth orbital environment under both relaxed and tension conditions. The polymers selected are those commonly used for spacecraft thermal control and those under consideration for use in spacecraft applications such as sunshields, solar sails, and inflatable and deployable structures. The dog-bone shaped samples of polymers that were flown were exposed on both the side of the MISSE 6 Passive Experiment Container (PEC) that was facing into the ram direction (receiving atomic oxygen, ultraviolet (UV) radiation, ionizing radiation, and thermal cycling) and the wake facing side (which was supposed to have experienced predominantly the same environmental effects except for atomic oxygen which was present due to reorientation of the International Space Station). A few of the tensile samples were coated with vapor deposited aluminum on the back and wired to determine the point in the flight when the tensile sample broke as recorded by a change in voltage that was stored on battery powered data loggers for post flight retrieval and analysis. The data returned on the data loggers was not usable. However, post retrieval observation and analysis of the samples was performed. This paper describes the preliminary analysis and observations of the polymers exposed on the MISSE 6 PFTE.

  4. Prediction of Splitting Tensile Strength of Concrete Containing Zeolite and Diatomite by ANN

    Directory of Open Access Journals (Sweden)

    E. Gülbandılar

    2017-01-01

    Full Text Available This study was designed to investigate with two different artificial neural network (ANN prediction model for the behavior of concrete containing zeolite and diatomite. For purpose of constructing this model, 7 different mixes with 63 specimens of the 28, 56 and 90 days splitting tensile strength experimental results of concrete containing zeolite, diatomite, both zeolite and diatomite used in training and testing for ANN systems was gathered from the tests. The data used in the ANN models are arranged in a format of seven input parameters that cover the age of samples, Portland cement, zeolite, diatomite, aggregate, water and hyper plasticizer and an output parameter which is splitting tensile strength of concrete. In the model, the training and testing results have shown that two different ANN systems have strong potential as a feasible tool for predicting 28, 56 and 90 days the splitting tensile strength of concrete containing zeolite and diatomite.

  5. The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

    Science.gov (United States)

    Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

    2017-10-01

    Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

  6. Tensile properties of V-5Cr-5Ti alloy after exposure in air environment

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1997-04-01

    Oxidation studies were conducted on V-5Cr-5Ti alloy specimens in an air environment to evaluate the oxygen uptake behavior of the alloy as a function of temperature and exposure time. The oxidation rates, calculated from parabolic kinetic measurements of thermogravimetric testing and confirmed by microscopic analysis of cross sections of exposed specimens, were 5, 17, and 27 {mu}m per year after exposure at 300, 400, and 500{degrees}C, respectively. Uniaxial tensile tests were conducted at room temperature and at 500{degrees}C on preoxidized specimens of the alloy to examine the effects of oxidation and oxygen migration on tensile strength and ductility. Correlations were developed between tensile strength and ductility of the oxidized alloy and microstructural characteristics such as oxide thickness, depth of hardened layer, depth of intergranular fracture zone, and transverse crack length.

  7. Tensile and superelastic fatigue characterization of NiTi shape memory cables

    Science.gov (United States)

    Sherif, Muhammad M.; Ozbulut, Osman E.

    2018-01-01

    This paper discusses the tensile response and functional fatigue characteristics of a NiTi shape memory alloy (SMA) cable with an outer diameter of 5.5 mm. The cable composed of multiple strands arranged as one inner core and two outer layers. The results of the tensile tests revealed that the SMA cable exhibits good superelastic behavior up to 10% strain. Fatigue characteristics were investigated under strain amplitudes ranging from 3% to 7% and a minimum of 2500 loading cycles. The evolutions of maximum tensile stress, residual strains, energy dissipation, and equivalent viscous damping under a number of loading cycles were analyzed. The fracture surface of a specimen subjected to 5000 loading cycles and 7% strain was discussed. Functional fatigue test results indicated a very high superelastic fatigue life cycle for the tested NiTi SMA cable.

  8. Effect of irradiation on the tensile properties of niobium-base alloys

    International Nuclear Information System (INIS)

    Grossbeck, M.L.; Heestand, R.L.; Atkin, S.D.

    1986-11-01

    The alloys Nb-1Zr and PWC-11 (Nb-1Zr-0.1C) were selected as prime candidate alloys for the SP-100 reactor. Since the mechanical properties of niobium alloys irradiated to end-of-life exposure levels of about 2 x 10 26 neutrons/m 2 (E > 0.1 MeV) at temperatures above 1300 K were not available, an irradiation experiment (B-350) in EBR-II was conducted. Irradiation creep, impact properties, bending fatigue, and tensile properties were investigated; however, only tensile properties will be reported in this paper. The tensile properties were studied since they easily reveal the common irradiation phenomena of hardening and embrittlement. Most attention was directed to testing at the irradiation temperature. Further testing was conducted at lower temperatures in order to scope the behavior of the alloys in cooldown conditions

  9. Post-irradiation dietary vitamin E does not affect the development of radiation-induced lung damage in rats

    NARCIS (Netherlands)

    Wiegman, EA; van Gameren, MA; Kampinga, HH; Szabo, BG; Coppes, RP

    The purpose of this study was to investigate whether application of post-irradiation vitamin E, an anti-oxidant, could prevent the development of radiation induced lung damage. Wistar rats were given vitamin E enriched or vitamin E deprived food starting from 4 weeks after 18 Gy single dose

  10. The repair/repopulation effects ratio in the postirradiation recovery of hexaploid wheat varieties contrast by their radioresistance

    International Nuclear Information System (INIS)

    Selezneva, E.M.; Sarapul'tsev, B.I.

    1988-01-01

    The cytogenic and morphometrical distinctions between hexaploid wheat varieties contrast by their radioresistance during the postirradiation period are attributed to the differential activity of caffeine-dependent repair processes; they are not a reliable function of the rate of aberrant cell elimination

  11. State of the VVER-1000 spent U-Gd fuel rods based on the results of post-irradiation examinations

    International Nuclear Information System (INIS)

    Shevlyakov, G.; Zvir, E.; Strozhuk, A.; Polenok, V.; Sidorenko, O.; Volkova, I.; Nikitin, O.

    2015-01-01

    The present paper is devoted to post-irradiation examinations (PIE) of U-Gd fuel rods with different geometry of the fuel pellets irradiated as part of the VVER-1000 fuel assembly. As evidenced by their PIE data, they did not exhaust their service life based on the main parameters (geometrical dimensions, corrosion state, and release of fission product gases). (author)

  12. Effects of ablation energy and post-irradiation on the structure and properties of titanium dioxide nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Guillén, G. García [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León, México (Mexico); Palma, M. I. Mendivil [Centro de Investigación en Materiales Avanzados (CIMAV), Unidad Monterrey, PIIT, Apodaca, Nuevo León, México (Mexico); Avellaneda, D.; Castillo, G.A.; Roy, T.K. Das [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); and others

    2017-05-31

    Highlights: • Highlights • TiO{sub 2} nanomaterials were prepared by PLALM. • Characterized these nanomaterials using TEM, XPS, XRD, optical and luminescence measurements. • Morphology of these nanomaterials were dependent on ablation wavelength, fluence and post-irradiation time. • Laser post irradiation modified the size, morphology and structure of these TiO{sub 2} nanomaterials. - Abstract: Nanomaterials of titanium oxide were prepared by pulsed laser ablation of a titanium metal target in distilled water. The ablation was performed at different laser energy (fluence) using a nanosecond pulsed Nd:YAG laser output of 1064 and 532 nm. A post-irradiation of titanium oxide nanocolloids obtained by ablation using 532 nm was carried out to explore its effects on the structure and properties. Analysis of morphology, crystalline phase, elemental composition, chemical state, optical and luminescent properties were performed using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), UV–-vis absorption spectroscopy and room temperature photoluminescence spectroscopy. It was found that titanium oxide nanomaterial morphologies and optical properties were determined by ablation wavelength and fluence. Further, nanocolloids prepared by 532 nm ablation showed a crystalline phase change by laser post-irradiation. The results showed that pulsed laser ablation in liquid as well as post-irradiation were effective in modifying the final structure and properties of titanium oxide nanocolloids.

  13. Microstructure and mechanical properties of neutron irradiated OFHC-copper before and after post-irradiation annealing

    DEFF Research Database (Denmark)

    Singh, B.N.; Edwards, D.J.; Toft, P.

    2001-01-01

    of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates theproblem of yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade induced source hardening (CISH) and the dispersed...

  14. Effects of ablation energy and post-irradiation on the structure and properties of titanium dioxide nanomaterials

    International Nuclear Information System (INIS)

    Guillén, G. García; Shaji, S.; Palma, M. I. Mendivil; Avellaneda, D.; Castillo, G.A.; Roy, T.K. Das

    2017-01-01

    Highlights: • Highlights • TiO_2 nanomaterials were prepared by PLALM. • Characterized these nanomaterials using TEM, XPS, XRD, optical and luminescence measurements. • Morphology of these nanomaterials were dependent on ablation wavelength, fluence and post-irradiation time. • Laser post irradiation modified the size, morphology and structure of these TiO_2 nanomaterials. - Abstract: Nanomaterials of titanium oxide were prepared by pulsed laser ablation of a titanium metal target in distilled water. The ablation was performed at different laser energy (fluence) using a nanosecond pulsed Nd:YAG laser output of 1064 and 532 nm. A post-irradiation of titanium oxide nanocolloids obtained by ablation using 532 nm was carried out to explore its effects on the structure and properties. Analysis of morphology, crystalline phase, elemental composition, chemical state, optical and luminescent properties were performed using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), UV–-vis absorption spectroscopy and room temperature photoluminescence spectroscopy. It was found that titanium oxide nanomaterial morphologies and optical properties were determined by ablation wavelength and fluence. Further, nanocolloids prepared by 532 nm ablation showed a crystalline phase change by laser post-irradiation. The results showed that pulsed laser ablation in liquid as well as post-irradiation were effective in modifying the final structure and properties of titanium oxide nanocolloids.

  15. Reconstruction of the anus, rectovaginal septum, and distal part of the vagina after postirradiation necrosis. Report of a unique case

    International Nuclear Information System (INIS)

    Nowacki, M.P.; Towpik, E.

    1988-01-01

    Successful repair of postirradiation total loss of the anal sphincters, rectovaginal septum, and distal part of the vagina is reported. Gracilis muscle flap was used as a substitute sphincter. Part of the muscle was wrapped-up in a split skin graft. To the authors' knowledge, this is the first report on new application of gracilis muscle and split skin graft in perineal reconstruction

  16. Tensile and Creep Testing of Sanicro 25 Using Miniature Specimens

    Science.gov (United States)

    Dymáček, Petr; Jarý, Milan; Dobeš, Ferdinand; Kloc, Luboš

    2018-01-01

    Tensile and creep properties of new austenitic steel Sanicro 25 at room temperature and operating temperature 700 °C were investigated by testing on miniature specimens. The results were correlated with testing on conventional specimens. Very good agreement of results was obtained, namely in yield and ultimate strength, as well as short-term creep properties. Although the creep rupture time was found to be systematically shorter and creep ductility lower in the miniature test, the minimum creep rates were comparable. The analysis of the fracture surfaces revealed similar ductile fracture morphology for both specimen geometries. One exception was found in a small area near the miniature specimen edge that was cut by electro discharge machining, where an influence of the steel fracture behavior at elevated temperature was identified. PMID:29337867

  17. Tensile and Creep Testing of Sanicro 25 Using Miniature Specimens.

    Science.gov (United States)

    Dymáček, Petr; Jarý, Milan; Dobeš, Ferdinand; Kloc, Luboš

    2018-01-16

    Tensile and creep properties of new austenitic steel Sanicro 25 at room temperature and operating temperature 700 °C were investigated by testing on miniature specimens. The results were correlated with testing on conventional specimens. Very good agreement of results was obtained, namely in yield and ultimate strength, as well as short-term creep properties. Although the creep rupture time was found to be systematically shorter and creep ductility lower in the miniature test, the minimum creep rates were comparable. The analysis of the fracture surfaces revealed similar ductile fracture morphology for both specimen geometries. One exception was found in a small area near the miniature specimen edge that was cut by electro discharge machining, where an influence of the steel fracture behavior at elevated temperature was identified.

  18. Postirradiation examination of Peach Bottom HTGR Driver Fuel Element E06-01

    International Nuclear Information System (INIS)

    Dyer, F.F.; Wichner, R.P.; Martin, W.J.; Fairchild, L.L.; Kedl, R.J.; de Nordwall, H.J.

    1976-04-01

    The report presented describes the postirradiation examinations of driver fuel element E06-01, which had been irradiated an equivalent of 384 full-power days in Peach Bottom, Unit 1. The fuel element is described in detail and its temperature and irradiation service history briefly outlined. Results presented include: (1) visual observations; (2) critical dimensions of fuel compacts, sleeve, and spine; (3) axial distributions of gamma-emitting nuclides plus 3 H and 90 Sr; (4) radial distributions of these nuclides in the sleeve and spine at three axial locations in the fueled regions and three locations in the upper reflector; (5) metallographic examination of samples of fuel compact material; and (6) burnup determinations via radiochemical analyses at two compact locations

  19. Pre- and postirradiation care of the mouth in head and neck cancer patients

    International Nuclear Information System (INIS)

    Cohen, M.A.; Lownie, J.F.

    1982-01-01

    Radiotherapy plays an important role in the treatment of head and neck cancer. The effects of radiotherapy on the oral hard and soft tissues may range from a mild mucositis to severe caries and osteoradionecrosis. It is the responsibility of the dentist to treat and prevent the severe sequelae which may arise. This paper outlines the effects of radiotherapy on the oral structures and discusses the dental treatment of the patient during radiotherapy. Emphasis is placed on the prevention of complications. The head and neck cancer patient must be thoroughly examined by the dentist and treatment planning may then be divided into pre-irradiaton treatment, treatment during irradiation and post-irradiation treatment. The dentist thus forms an essential member of the team treating patients with head and neck cancer [af

  20. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1995-01-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analysis are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  1. Post-irradiation vasculopathy of intracranial major arteries in children; Report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, Shigeru; Ryu, Hiroshi; Yokoyama, Tetsuo; Ninchoji, Toshiaki; Shimoyama, Ichiro; Yamamoto, Seiji; Uemura, Kenichi [Hamamatsu Univ. School of Medicine, Shizuoka (Japan)

    1991-06-01

    We report two rare cases of post-irradiation vasculopathy of intracranial major arteries in children. A 13-year-old girl suffered from transient right hemiparesis 1 year after irradiation for suprasellar germinoma. Left carotid angiograms revealed marked stenoses of the intracranial internal carotid, middle cerebral, and anterior cerebral arteries, which were previously normal, and moyamoya vessels. A 2.5-year-old girl underwent internal irradiation with {sup 198}Au colloid for cystic craniopharyngioma. At the age of 10 years, she suddenly became unconscious after vomiting. Computed tomographic scans showed a right frontal intracerebral hematoma. Right carotid angiograms disclosed complete obstruction of the intracranial internal carotid, middle cerebral, and anterior cerebral arteries and moyamoya vessels, previously not present. The danger of radiation therapy causing occlusive vasculopathy in small and major cerebral arteries in children is emphasized. To prevent permanent ischemic neurological deficits, vasculopathy should be treated either medically or surgically as early as possible. (author).

  2. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1998-04-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analyses are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  3. Study of the enterotoxigenicity of enterobacteria and their resistance to antibiotics in postirradiation abacteriosis

    International Nuclear Information System (INIS)

    Korshunov, V.M.; Bodryagina, A.B.; Pinegin, B.V.

    1981-01-01

    Qualitative and quantitative composition of Enterobacteriaceal family was studied and the percentage of enterotoxigenic and antibiotic resistant strains was determined in the large intestine cavity of intact mice of CBA line as well as in the cavity and wall of the small intestine of those animals on the 7 day after γ-irradiation (900 R). It was ascertained that postirradiation abacteriosis was characterized by the penetration in quantity of Esub(coli,Pr. morganii) into the small intestine and by the emergence in the small intestine of non-determinable in the intestinal tract intact animals: Pr. vulgaris, Pr. mirabilis, Pr. rettgeri, Ent. aerogenes, Ent. cloacae, Ent. hafniae, Citrobacter freundii, Providencia alcalifaciens; all revealed representatives of enterobacteria were capable of establishing associative bond with the mucous membrane of the intestine. Enterobacteria synthesizing resistant to antibiotics enterotoxins were revealed in quantity in the wall and lumen of the small intestine of irradiated mice [ru

  4. Study on "1"4C content in post-irradiation graphite spheres of HTR-10

    International Nuclear Information System (INIS)

    Wang Shouang; Pi Yue; Xie Feng; Li Hong; Cao Jianzhu

    2014-01-01

    Since the production mechanism of the "1"4C in spherical fuel elements was similar to that of fuel-free graphite spheres, in order to obtain the amount of "1"4C in fuel elements and graphite spheres of HTR-10, the production mechanism of the "1"4C in graphite spheres was studied. The production sources of the "1"4C in graphite spheres and fuel elements were summarized, the amount of "1"4C in the post-irradiation graphite spheres was calculated, the decomposition techniques of graphite spheres were compared, and experimental methods for decomposing the graphite spheres and preparing the "1"4C sample were proposed. The results can lay the foundation for further experimental research and provide theoretical calculations for comparison. (authors)

  5. Post-irradiation repairing processes of glucose-6-phosphate dehydrogenase and catalase from Hansenula Polymorpha yeast

    International Nuclear Information System (INIS)

    Postolache, Carmen; Postolache, Cristian; Dinu, Diana; Dinischiotu, Anca; Sahini, Victor Emanuel

    2002-01-01

    The post-irradiation repairing mechanisms of two Hansenula Polymorpha yeast enzymes, glucose-6-phosphate dehydrogenase and catalase, were studied. The kinetic parameters of the selected enzymes were investigated over one month since the moment of γ-irradiation with different doses in the presence of oxygen. Dose dependent decrease of initial reaction rates was noticed for both enzymes. Small variation of initial reaction rate was recorded for glucose-6-phosphate dehydrogenase over one month, with a decreasing tendency. No significant electrophoretic changes of molecular forms of this enzyme were observed after irradiation. Continuous strong decrease of catalase activity was evident for the first 20 days after irradiation. Partial recovery process of the catalytic activity was revealed by this study. (authors)

  6. Decomposition of nuclear chromatin of the rat thymus within the postirradiation period

    International Nuclear Information System (INIS)

    Vodolazskaya, N.A.

    1975-01-01

    Fractional composition of DNP histones and of salt extracts of the thymus of rats has been studied 2 to 8 hours after γ-irradiation with 600r (Co 60 ). Simultaneously, histones/DNA ratio has been determined in the nucleoprotein and in its salt-soluble fragments after fractionation of the salt extracts on phosphatecellulose. It has been shown that 2 to 4 hours following the exposure, the histone/DNA ratio in DNP preparations does not vary from the control. Subsequently, however, it slightly decreases. It has been found that the postirradiation DNP decomposition is accompanied by the formation of fragments which, in addition to a free DNA, comprise complexes with the decreased and increased histone/DNA ratio as compared to the original DNP

  7. Post-irradiation brain-necrosis resulting in apoplexia and death after 33 years of irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, A [Foevarosi Laszlo Korhaz, Budapest (Hungary). Korbonctani es Korszoevettani Oszt.

    1980-04-01

    A case of post-irradiation brain-necrosis resulting in apoplexia of the cerebellum after 33 years of irradiation (19984 r.) of a presumptive cerebellar tumour is reported. The pathohistologic study revealed symptoms of the ''late'' damage and the vascular changes appeared to be the most prominent. The thickening of the vessel walls, hyperplasia of collagen fibres and deposition of calcium in the media, were the most characteristic lesions revealed. In some of the small vessels isolated calcification of the media was observed. It seems most probable that in the development of apoplexia vascular alterations could play an important role. In the available literature no report has been found on a similarly long interval elapsing between the irradiation and death.

  8. Post-irradiation brain-necrosis resulting in apoplexia and death after 33 years of irradiation

    International Nuclear Information System (INIS)

    Froehlich, A.

    1980-01-01

    A case of post-irradiation brain-necrosis resulting in apoplexia of the cerebellum after 33 years of irradiation (19984 r.) of a presumptive cerebellar tumour is reported. The pathohistologic study revealed symptoms of the ''late'' damage and the vascular changes appeared to be the most prominent. The thickening of the vessel walls, hyperplasia of collagen fibres and deposition of calcium in the media, were the most characteristic lesions revealed. In some of the small vessels isolated calcification of the media was observed. It seems most probable that in the development of apoplexia vascular alterations could play an important role. In the available literature no report has been found on a similarly long interval elapsing between the irradiation and death. (author)

  9. A comparative study of post-irradiation growth kinetics of spheroids and monolayers

    International Nuclear Information System (INIS)

    Dertinger, J.; Luecke-Huhle, C.

    1975-01-01

    Post-irradiation growth kinetics of γ-irradiated spheroid and monolayer cells in exponential growth phase was investigated by means of dose-response curves based on cell counts after specified time intervals following irradiation. A mathematical model of cell-growth after irradiation was fitted to these curves. The model parameters (related to division delay and growth of non-surviving cells) obtained from this analysis consistently indicated increasing resistance to sub-lethal damage of cells cultured as multicellular spheroids under conditions of increasing three-dimensional contact. In contrast, no indication of an increased radiation-resistance was found with cells cultured on a substratum under a variety of conditions. (author)

  10. Data base and postirradiation examination results of spent WWER-1000 fuel elements and assemblies

    International Nuclear Information System (INIS)

    Kanashov, B.A.; Polenok, V.S.; Smirnov, A.V.; Zhitelev, V.A.

    1995-01-01

    The report presents the results of the postirradiation shape change examination of standard fuel elements and fuel assemblies irradiated in standard conditions in Russian power reactors of the WWER-1000 type. The information is based on the results obtained at the Fuel Research Department of the Federal Scientific Centre Research Institute of Atomic Reactors (FSC RIAR, Dimitrovgrad, Russian Federation) within the period from 1987 to 1994. Emphasis is placed on such experimental and calculational data as: length, cross-section dimensions and shape of FAs with wrapper; change of standard FA skeleton members dimensions; fuel bundle elongation; change of the fuel cladding outer diameter; and elongation and change of the fuel stack outer diameter. (author)

  11. Pre- and postirradiation care of the mouth in head and neck cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M A; Lownie, J F [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Surgery

    1982-08-01

    Radiotherapy plays an important role in the treatment of head and neck cancer. The effects of radiotherapy on the oral hard and soft tissues may range from a mild mucositis to severe caries and osteoradionecrosis. It is the responsibility of the dentist to treat and prevent the severe sequelae which may arise. This paper outlines the effects of radiotherapy on the oral structures and discusses the dental treatment of the patient during radiotherapy. Emphasis is placed on the prevention of complications. The head and neck cancer patient must be thoroughly examined by the dentist and treatment planning may then be divided into pre-irradiaton treatment, treatment during irradiation and post-irradiation treatment. The dentist thus forms an essential member of the team treating patients with head and neck cancer.

  12. Tensile Strength of Water Exposed to Pressure Pulses

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Mørch, Knud Aage

    2012-01-01

    at an extended water-solid interface by imposing a tensile stress pulse which easily causes cavitation. Next, a compressive pulse of duration ~1 ms and a peak intensity of a few bar is imposed prior to the tensile stress pulse. A dramatic increase of the tensile strength is observed immediately after......It is well known that pressurization for an extended period of time increases the tensile strength of water, but little information is available on the effect of pressure pulses of short duration. This is addressed in the present paper where we first measure the tensile strength of water...

  13. Pre- and postirradiation properties of brazed joints of AISI 316L stainless steel

    International Nuclear Information System (INIS)

    Brossa, M.; Franconi, E.; Guerreschi, U.; Pierazzi, L.; Poggi, P.; Rustia, V.

    1994-01-01

    An extensive test campaign has been performed to verify the reliability and the endurance of brazed joints between AISI 316L parts for structural applications in the nuclear field. The tests, conducted for comparison with three different high melting temperature alloys, included tensile tests (normal and shear), fatigue tests (fatigue crack propagation, low cycle fatigue, 4-point bending fatigue) and impact tests; besides, tensile tests have been performed with both unirradiated and irradiated specimens. Generally, the tests demonstrated satisfactory mechanical properties of the joints and revealed occasionally strong differences in the behaviour of the different brazing alloys, thus providing important design indications. ((orig.))

  14. Post-irradiation inactivation, protection, and repair of the sulfhydryl enzyme malate synthase

    International Nuclear Information System (INIS)

    Durchschlag, H.; Zipper, P.

    1985-01-01

    Malate synthase from baker's yeast, a trimeric sulfhydryl enzyme with one essential sulfhydryl group per subunit, was inactivated by 2 kGy X-irradiation in air-saturated aqueous solution (enzyme concentration: 0.5 mg/ml). The radiation induced changes of enzymic activity were registered at about 0,30,60 h after irradiation. To elucidate the role of OH - , O 2 , and H 2 O 2 in the X-ray inactivation of the enzyme, experiments were performed in the absence of presence of different concentrations of specific additives (formate, superoxide dismutase, catalase). These additives were added to malate synthase solutions before or after X-irradiation. Moreover, repairs of inactivated malate synthase were initiated at about 0 or 30 h after irradiation by means of the sulfhydryl agent dithiothreitol. Experiments yielded the following results: 1. Irradiation of malate synthase in the absence of additives inactivated the enzyme immediately to a residual activity Asub(r)=3% (corresponding to a D 37 =0.6 kGy), and led to further slow inactivation in the post-irradiation phase. Repairs, initiated at different times after irradiation, restored enzymic activity considerably. The repair initiated at t=0 led to Asub(r)=21%; repairs started later on resulted in somewhat lower activities. The decay of reparability, however, was found to progress more slowly than post-irradiation inactivation itself. After completion of repair the activities of repaired samples did not decrease significantly. 2. The presence of specific additives during irradiation caused significant protective effects against primary inactivation. The protection by formate was very pronounced (e.g., Asub(r)=72% and D 37 =6 kGy for 100 mM formate). The presence of catalytic amounts of superoxide dismutase and/or catalase exhibited only minor effects, depending on the presence and concentration of formate. (orig.)

  15. Heat-treated mineral-yeast as a potent post-irradiation radioprotector

    International Nuclear Information System (INIS)

    Anzai, Kazunori; Ueno, Megumi; Nyui, Minako; Ikota, Nobuo; Kagiya, Tsutomu V.

    2008-01-01

    In vivo radioprotection of C3H mice by i.p. administration of Zn-, Mn-, Cu-, or Se-containing heat-treated Saccharomyces serevisiae yeast sample was examined. The 30-day survival of the group treated 30 min before 7.5 Gy whole-body X-irradiation with mineral-containing yeast powders suspended in 0.5% methylcellulose was significantly higher than that of control group. When mineral-yeast was administered immediately after irradiation, the survival rate was even higher and Zn- or Cu-yeast showed the highest rate (more than 90%). Although treatment with simple yeast showed a high survival rate (73%), it was significantly lower than that obtained by the Zn-yeast treatment. The effects of Zn-yeast were studied further. When the interval between irradiation and administration was varied, the protective activity of Zn-yeast decreased gradually by increasing the interval but was still significantly high for the administration at 10 h post-irradiation. The dose reduction factor of Zn-yeast (100 mg/kg, i.p. administration immediately after irradiation) was about 1.2. When the suspension of Zn-yeast was fractionated by centrifugation, the insoluble fraction showed a potent effect, while the soluble fraction had only a moderate effect. In conclusion, mineral-yeast, especially Zn-yeast, provides remarkable post-irradiation protection against lethal whole body X-irradiation. The activity is mainly attributable to the insoluble fraction, whereas some soluble components might contribute to the additional protective activity. (author)

  16. AGR-1 Compact 1-3-1 Post-Irradiation Examination Results

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport (INL 2015). A series of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously (Grover, Petti, and Maki 2010, Maki 2009).

  17. Evaluation of tensile strength and fracture behavior of friction welded ...

    Indian Academy of Sciences (India)

    In the present study an attempt was made to join austenitic stainless steel ... Experimental details ... This test was carried out on the friction welded samples of .... phenomenon was observed to be true if the rotational speed was increased up to ...

  18. Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2016-01-01

    Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

  19. Discrete analysis of clay layer tensile strength

    International Nuclear Information System (INIS)

    Le, T.N.H.; Ple, O.; Villard, P.; Gourc, J.P.

    2010-01-01

    The Discrete Element Method is used to investigate the tensile behaviour and cracks mechanisms of a clay material submitted to bending loading. It is the case of compacted clay liners in landfill cap cover application. Such as the soil tested in this study is plastic clay, the distinct elements model was calibrated with previous data results by taking into account cohesive properties. Various contact and cohesion laws are tested to show that the numerical model is able to reproduce the failure mechanism. Numerical results are extending to simulate a landfill cap cover and comparing to experimental large scale field bending tests achieved in a real site of storage. (authors)

  20. Welding wires for high-tensile steels

    International Nuclear Information System (INIS)

    Laz'ko, V.E.; Starova, L.L.; Koval'chuk, V.G.; Maksimovich, T.L.; Labzina, I.E.; Yadrov, V.M.

    1993-01-01

    Strength of welded joints in arc welding of high-tensile steels of mean and high thickness by welding wires is equal to approximately 1300 MPa in thermohardened state and approximately 600 MPa without heat treatment. Sv-15Kh2NMTsRA-VI (EhK44-VI) -Sv-30Kh2NMTsRA-VI (EkK47-VI) welding wires are suggested for welding of medium-carbon alloyed steels. These wires provide monotonous growth of ultimate strength of weld metal in 1250-1900 MPa range with increase of C content in heat-treated state

  1. Stability of germanene under tensile strain

    KAUST Repository

    Kaloni, Thaneshwor P.

    2013-09-01

    The stability of germanene under biaxial tensile strain and the accompanying modifications of the electronic properties are studied by density functional theory. The phonon spectrum shows that up to 16% strain the germanene lattice is stable, where the Dirac cone shifts towards higher energy and hole-doped Dirac states are achieved. The latter is due to weakening of the Ge-Ge bonds and reduction of the s-p hybridization. Our calculated Grüneisen parameter shows a similar dependence on the strain as reported for silicene (which is different from that of graphene). © 2013 Elsevier B.V. All rights reserved.

  2. Stability of germanene under tensile strain

    KAUST Repository

    Kaloni, Thaneshwor P.; Schwingenschlö gl, Udo

    2013-01-01

    The stability of germanene under biaxial tensile strain and the accompanying modifications of the electronic properties are studied by density functional theory. The phonon spectrum shows that up to 16% strain the germanene lattice is stable, where the Dirac cone shifts towards higher energy and hole-doped Dirac states are achieved. The latter is due to weakening of the Ge-Ge bonds and reduction of the s-p hybridization. Our calculated Grüneisen parameter shows a similar dependence on the strain as reported for silicene (which is different from that of graphene). © 2013 Elsevier B.V. All rights reserved.

  3. Relationship between micro-porosity and tensile properties of 6063 alloy

    Directory of Open Access Journals (Sweden)

    Li Xiehua

    2013-01-01

    Full Text Available The micro-porosity is usually present in the as-cast microstructure, which decreases the tensile strength and ductility and therefore limit the application of cast aluminum parts. Although much work has been done to investigate the effects of various casting parameters on the formation of porosity in various aluminum alloys, up to now, little information has been available for the relationship between micro-porosity and tensile properties of 6063 alloy. In this study, the influences of size and area fraction of micro-porosity on the tensile properties and fracture behavior of 6063 aluminum alloy were investigated by means of tensile testing, optical microscopy (OM, and scanning electron microscopy (SEM. The tensile tests were conducted in air at 100 ℃, 200 ℃ and 300 ℃, respectively. Results show that the large micro-porosity with sizes between 100 μm and 800 μm located at the center and top of the ingot, while the small micro-porosity with size between 2 μm and 60 μm distributed at the edge and bottom of the ingot. The area fraction of micro-porosity at the center of the ingot is much bigger than that at the edge of the ingot. When tested at 100 ℃, with the decrease in the area fraction of micro-porosity from the top of the ingot to the bottom of the ingot, the ultimate tensile strength, yield strength and the elongation are increased from 82 to 99 MPa, 32 to 66 MPa and 7% to 11%, respectively. When the temperature is no more than 200 ℃, the strain hardening exponent decreases with an increase in the area fraction of micro-porosity; while the deviation disappears when the temperature reaches 300 ℃. The fracture mode of the alloy is greatly influenced by the size and area fraction of the micro-porosity.

  4. 2D micromechanical analysis of SiC/Al metal matrix composites under tensile, shear and combined tensile/shear loads

    DEFF Research Database (Denmark)

    Qing, Hai

    2013-01-01

    The influence of interface strength and loading conditions on the mechanical behavior of the metal-matrix composites is investigated in this paper. A program is developed to generate automatically 2D micromechanical Finite element (FE) models including interface, in which both the locations...... and dimensions of Silicon-Carbide (SiC) particles are randomly distributed. Finite element simulations of the deformation and damage evolution of SiC particle reinforced Aluminum (Al) alloy composite are carried out for different microstructures and interphase strengths under tensile, shear and combined tensile....../shear loads. 2D cohesive element is applied to describe the fracture and failure process of interphase, while the damage models based on maximum principal stress criterion and the stress triaxial indicator are developed within Abaqus/Standard Subroutine USDFLD to simulate the failure process of SiC particles...

  5. Tensile-property characterization of thermally aged cast stainless steels

    International Nuclear Information System (INIS)

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K.

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components

  6. Interspecific variation of intracellular localization and postirradiation movement of Ku70-protein in fibroblastic cells

    International Nuclear Information System (INIS)

    Endoh, Daiji; Hayashi, Masanobu; Okui, Toyo; Kawase, Shiro; Kon, Yasushiro

    2003-01-01

    Ku (Ku70 and Ku80) Proteins are known as components of DNA-dependent protein kinase (DNA-PK) and play an important role for DNA repair. We previously reported that more than 70% of Ku proteins were located in cytoplasm of rat cells, the Ku proteins moved into nuclei of normal rat cells after X-irradiation, Ku proteins also moved into nuclei after X-irradiation but were not retained in nucleus of radiosensitive LEC rat cells. While reports have been shown about mechanisms on nuclear localization of Ku proteins, how Ku proteins export from nucleus is poorly understood. Here we show that C-terminal region of Ku70 protein is important for its cytoplasmic localization. When transfected into LEC rat cells, exogenous intact Ku70 (1-609) tagged with enhanced green fluorescent protein (EGFP-Ku70) localized mainly in the cytoplasm, whereas C-terminal-deletion mutant of Ku70 (1-593) tagged with EGFP (EGFP-Ku70D) was mainly localized in the nucleus. After X-irradiation, the endogenous intact EGFP-Ku70 once moved into nucleus, but returned into the cytoplasm. On the other hand, EGFP-Ku70D was retained in nucleus for two hours after X-irradiation. These results suggest that C-terminal region of Ku70 is included in the postirradiation nuclear export. Next, we investigated the intracellular localization of Ku70 proteins and the movement after X-irradiation of fibroblastic cells prepared from some mammalian species. Ku70 proteins were localized in nucleus and the postirradiation-extranuclear transport was not observed in human and African green monkey cells. On the other hand, Ku70 proteins were mainly localized in cytoplasm and moved into nucleus in mouse, Chinese hamster, Golden hamster, cotton rat, squirrel, cat and dog cells. These results may show that alternatively Ku70 protein is localized in the cytoplasm or nucleus depends on species and translocation of cytoplasmic Ku70 into nucleus is a response against low dose irradiation in fibroblasts of rodents, cats and dogs

  7. Main results of post-irradiation examinations of new-generation fuel assemblies VVER-1000

    International Nuclear Information System (INIS)

    Zvir, E.; Markov, D.; Polenok, V.; Zhitelev, V.; Kobylyansky, G.

    2009-01-01

    To increase the competitiveness of Russian nuclear fuel at the foreign market and to improve its technical and economic performance in order to provide a necessary level of safety, it is necessary to solve certain important tasks: Increase of fuel burn-up; Extension of operational lifetime of fuel assemblies and operational reliability of nuclear fuel; Introduction of cost-beneficial and flexible fuel cycles. Alternative fuel assemblies TVSA VVER-1000 and TVS-2 are used as a basis to optimize the nuclear fuel and develop advanced fuel cycles for nuclear power plants with VVER-1000 reactor types. Four fuel assemblies TVSA operated during 1 and up to 6 reactor cycles, reference fuel assembly TVS-2 operated during three reactor cycles and achieved an average fuel burnup of 48MW·day/kgU as well as failed fuel assembly TVS-2 operated during one cycle were examined at RIAR in recent years. The main objectives of these examinations were to obtain experimental data in support of operational integrity of products or to find out reasons of their failure. The performed post-irradiation examinations confirmed the operational integrity of alternative fuel assemblies TVSA including their geometrical stability up to the average fuel burnup of 55 MW·day/kgU over the fuel assembly (FA) (up to the maximal fuel burnup of ∼73 MW·day/kgU in fuel rods) and of TVS-2 up to the average fuel burnup of 48 MW·day/kgU over the fuel assembly. The changes introduced in the design of VVER-1000 fuel assembly during the development of alternative fuel assembly TVSA and TVS-2 did not make any negative effect on fuel rods. It was proved that causes of fuel rod failure were not related to design features of fuel assemblies. The design features and operating conditions of fuel assemblies under examinations are briefly described. Post-irradiation examinations proved the geometrical stability of fuel assemblies TVSA and TVS-2 under operation up to the fuel burnup of ∼50 MW day/kgU, as for the

  8. Miniature tensile test specimens for fusion reactor irradiation studies

    International Nuclear Information System (INIS)

    Klueh, R.L.

    1985-01-01

    Three miniature sheet-type tensile specimens and a miniature rod-type specimen are being used to determine irradiated tensile properties for alloy development for fusion reactors. The tensile properties of type 316 stainless steel were determined with these different specimens, and the results were compared. Reasonably good agreement was observed. However, there were differences that led to recommendations on which specimens are preferred. 4 references, 9 figures, 6 tables

  9. A user's manual for managing database system of tensile property

    International Nuclear Information System (INIS)

    Ryu, Woo Seok; Park, S. J.; Kim, D. H.; Jun, I.

    2003-06-01

    This manual is written for the management and maintenance of the tensile database system for managing the tensile property test data. The data base constructed the data produced from tensile property test can increase the application of test results. Also, we can get easily the basic data from database when we prepare the new experiment and can produce better result by compare the previous data. To develop the database we must analyze and design carefully application and after that, we can offer the best quality to customers various requirements. The tensile database system was developed by internet method using Java, PL/SQL, JSP(Java Server Pages) tool

  10. Post-irradiation mechanical tests on F82H EB and TIG welds

    International Nuclear Information System (INIS)

    Rensman, J.; Osch, E.V. van; Horsten, M.G.; D'Hulst, D.S.

    2000-01-01

    The irradiation behaviour of electron beam (EB) and tungsten inert gas (TIG) welded joints of the reduced-activation martensitic steel IEA heat F82H-mod. was investigated by neutron irradiation experiments in the high flux reactor (HFR) in Petten. Mechanical test specimens, such as tensile specimens and KLST-type Charpy impact specimens, were neutron irradiated up to a dose level of 2-3 dpa at a temperature of 300 deg. C in the HFR reactor in Petten. The tensile results for TIG and EB welds are as expected with practically no strain hardening capacity left. Considering impact properties, there is a large variation in impact properties for the TIG weld. The irradiation tends to shift the DBTT of particularly the EB welds to very high values, some cases even above +250 deg. C. PWHT of EB-welded material gives a significant improvement of the DBTT and USE compared to the as-welded condition

  11. Post-irradiation examination of a 13000C-HTR fuel experiment Project J 96.M3

    International Nuclear Information System (INIS)

    Bueger, J. de; Roettger, H.

    1977-01-01

    A large variety of loose coated fuel particles have been irradiated in the BR2 at Mol/Belgium at temperatures between 1200 0 C and 1400 0 C and up to a fast neutron fluence of 1.2x1022 cm -2 (E>0.1 MeV) as a Euratom sponsored experiment for the advanced testing of HTR fuel. The specimens have been provided by Belgonucleaire and the Dragon Project. A short description of the experiment as well as the results of post-irradiation examination mainly carried out at Petten (N.H.), The Netherlands, are presented here. The post-irradiation examination has shown that the required performance can be achieved by a number of the tested fuel specimens without serious damage

  12. Biochemical effects of heat shock and caffeine on post-irradiation oxic and anoxic damage in barley seeds of low and high water content

    International Nuclear Information System (INIS)

    Singh, S.P.; Kesavan, P.C.

    1991-01-01

    Wet heat shock (60 o C, 90s) and caffeine (3.8 x 10 -4 M) afford significant radioprotection against post-irradiation O 2 -dependent damage which develops in seeds of ∼ 3.5% moisture content. The damage was assessed in terms of seedling injury on the eighth day of growth. An increase in seedling injury is clearly seen, associated with a parallel increase in the peroxidase activity. There is a concomitant decrease in the content of total peroxides. Both these post-irradiation treatments potentiate the O 2 -independent component of seedling injury, irrespective of the seed moisture content. Analysis of the peroxidase activity in the seedlings using non-denaturing polyacrylamide gel electrophoresis reveals that two additional bands appear with the post-irradiation oxic damage. Radioprotection against this damage by caffeine, heat shock and O 2 -free post-irradiation hydration is accompanied by the disappearance of these two additional bands. (author)

  13. Effect of the hydrolytic state of dietary protein on post-irradiation morbidity and mucosal cell regeneration

    International Nuclear Information System (INIS)

    Beitler, M.K.; Mahler, P.A.; Yamanaka, W.K.; Guy, D.G.; Hutchinson, M.L.

    1987-01-01

    Diets containing hydrolyzed casein have been observed to enhance post-irradiation intestinal mucosal recovery. The intake and the composition of such diets were not carefully controlled. This study attempted to do so. Male specific pathogen-free Sprague-Dawley rats were randomized to receive either an enzymatically hydrolyzed casein semi-purified diet (EHC), a whole casein semi-purified diet (WC), or powdered lab chow (C). All diets were isonitrogenous, and the WC and C rats were pair-fed to the ad libitum fed EHC rats. Seven days after initiation of feeding, the rats were abdominally irradiated with a single 9.0 Gy dose of 137Cs gamma rays. The rats were continued on the diets for another 5 days. Intestinal mucosa from transverse segments at the duodenum, jejunum, proximal ileum, and distal ileum were measured for incorporation of ( 3 H methyl) thymidine 1 hour after intraperitoneal injection. Incorporation reached a maximum by day 4 post-irradiation regardless of diet or segment. Incorporation in the duodenum was enhanced by the EHC diet compared to the C diet, while the incorporation in the jejunum was initially suppressed by the EHC diet compared to the WC diet. In the jejunum, the number of mitoses per crypt of 25 anti-mesenteric crypts post-irradiation was increased by the EHC diet. Prior to irradiation, all groups gained similar amounts of weight. After irradiation, the C rats lost weight, while the EHC and WC rats remained the same or gained weight. Guaiac tests for occult blood were negative prior to irradiation, but positive for all rats on days 1-5 postirradiation. When calorie and protein intakes were controlled, different areas of the small intestine responded differently to EHC

  14. International interest in the BONAPARTE measurement bench. Post-irradiation examination of lower-enriched fuel plates

    International Nuclear Information System (INIS)

    2014-01-01

    The Belgian Nuclear Research Center SCK-CEN has developed a measurement bench (BONAPARTE) for the non-destructive analysis on fuel plate and rod type fuel elements. BONAPARTE is a modular device that can be employed for many purposes. The article discusses the employment of the BONAPARTE device for the accurate full post-irradiation mapping of fuel plate swelling with degree of precision of just a few micrometers.

  15. Transfer of test samples and wastes between post-irradiation test facilities (FMF, AGF, MMF)

    International Nuclear Information System (INIS)

    Ishida, Yasukazu; Suzuki, Kazuhisa; Ebihara, Hikoe; Matsushima, Yasuyoshi; Kashiwabara, Hidechiyo

    1975-02-01

    Wide review is given on the problems associated with the transfer of test samples and wastes between post-irradiation test facilities, FMF (Fuel Monitoring Facility), AGF (Alpha Gamma Facility), and MMF (Material Monitoring Facility) at the Oarai Engineering Center, PNC. The test facilities are connected with the JOYO plant, an experimental fast reactor being constructed at Oarai. As introductory remarks, some special features of transferring irradiated materials are described. In the second part, problems on the management of nuclear materials and radio isotopes are described item by item. In the third part, the specific materials that are envisaged to be transported between JOYO and the test facilities are listed together with their geometrical shapes, dimensions, etc. In the fourth part, various routes and methods of transportation are explained with many block charts and figures. Brief explanation with lists and drawings is also given to transportation casks and vessels. Finally, some future problems are discussed, such as the prevention of diffusive contamination, ease of decontamination, and the identification of test samples. (Aoki, K.)

  16. Defect sizing of post-irradiated nuclear fuels using grayscale thresholding in their radiographic images

    International Nuclear Information System (INIS)

    Chaudhary, Usman Khurshid; Iqbal, Masood; Ahmad, Munir

    2010-01-01

    Quantification of different types of material defects in a number of reference standard post-irradiated nuclear fuel image samples have been carried out by virtue of developing a computer program that takes radiographic images of the fuel as input. The program is based on user adjustable grayscale thresholding in the regime of image segmentation whereby it selects and counts the pixels having graylevel values less than or equal to the computed threshold. It can size the defects due to chipping in nuclear fuel, cracks, voids, melting, deformation, inclusion of foreign materials, heavy isotope accumulation, non-uniformity, etc. The classes of fuel range from those of research and power reactors to fast breeders and from pellets to annular and vibro-compacted fuel. The program has been validated against ground truth realities of some locally fabricated metallic plates having drilled holes of known sizes simulated as defects in them in which the results indicate that it either correctly selects and quantifies at least 94% of the actual required regions of interest in a given image or it gives less than 8.1% false alarm rate. Also, the developed program is independent of image size.

  17. Defect sizing of post-irradiated nuclear fuels using grayscale thresholding in their radiographic images

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, Usman Khurshid, E-mail: ukhurshid@hotmail.co [Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad 45650 (Pakistan); Iqbal, Masood, E-mail: masiqbal@hotmail.co [Nuclear Engineering Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad 45650 (Pakistan); Ahmad, Munir [Nondestructive Testing Group, Directorate of Technology, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad 45650 (Pakistan)

    2010-10-15

    Quantification of different types of material defects in a number of reference standard post-irradiated nuclear fuel image samples have been carried out by virtue of developing a computer program that takes radiographic images of the fuel as input. The program is based on user adjustable grayscale thresholding in the regime of image segmentation whereby it selects and counts the pixels having graylevel values less than or equal to the computed threshold. It can size the defects due to chipping in nuclear fuel, cracks, voids, melting, deformation, inclusion of foreign materials, heavy isotope accumulation, non-uniformity, etc. The classes of fuel range from those of research and power reactors to fast breeders and from pellets to annular and vibro-compacted fuel. The program has been validated against ground truth realities of some locally fabricated metallic plates having drilled holes of known sizes simulated as defects in them in which the results indicate that it either correctly selects and quantifies at least 94% of the actual required regions of interest in a given image or it gives less than 8.1% false alarm rate. Also, the developed program is independent of image size.

  18. Postirradiation examination and evaluation of Fort St. Vrain fuel element 1-0743

    International Nuclear Information System (INIS)

    Saurwein, J.J.; Miller, C.M.; Young, C.A.

    1981-05-01

    Fort St. Vrain (FSV) fuel element 1-0743 was irradiated in core location 17.04.F.06 from July 3, 1976 until February 1, 1979. The element experienced an average fast neutron exposure of about 0.95 x 10 25 n/m 2 (E > 29 fJ)/sub HTGR/, a time-and-volume-averaged fuel temperature in the vicinity of 680 0 C, fissile and fertile particle burnups of approximately 6.2% and 0.3%, respectively, and a total burnup of 12,210 MWd/tonne. The postirradiation examination revealed that the element was in excellent condition. No cracks were observed on any of the element surfaces. The structural integrity of the fuel rods was good. No evidence of mechanical interaction between the fuel rods and fuel body was observed. Calculated irradiation parameters obtained with HTGR design codes were compared with measured data. Radial and axial power distributions, irradiation temperatures, neutron fluences, and fuel burnups were in good agreement with measurements. Calculated fuel rod strains were about a factor of three greater than were observed

  19. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    International Nuclear Information System (INIS)

    Schwarze, G.E.; Frasca, A.J.

    1994-01-01

    The effects of neutrons and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 10 13 n/cm 2 and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are given in this paper. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed

  20. Advanced post-irradiation examination techniques for water reactor fuel. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    2002-03-01

    The purpose of the meeting was to provide and overview of the status of post-irradiation examination (PIE) techniques for water cooled reactor fuel assemblies and their components with emphasis given to advanced PIE techniques applied to high burnup fuel. Papers presented at the meeting described progress obtained in non-destructive (e.g. dimensional measurements, oxide layer thickness measurements, gamma scanning and tomography, neutron and X-ray radiography, etc.) and destructive PIE techniques (e.g. microstructural studies, elemental and isotopic analysis, measurement of physical and mechanical properties, etc.) used for investigation of water reactor fuel. Recent practice in high burnup fuel investigation revealed the importance of advanced PIE techniques, such as 3-D tomography, secondary ion mass spectrometry, laser flash, high resolution transmission and scanning electron microscopy, image analysis in microstructural studies, for understanding mechanisms of fuel behaviour under irradiation. Importance and needs for in-pile irradiation of samples and rodlets in instrumented rigs were also discussed. This TECDOC contains 20 individual papers presented at the meeting; each of the papers has been indexed separately