WorldWideScience

Sample records for aluminum clad al-li

  1. Comparative Analysis of Al-Li Alloy and Aluminum Honeycomb Panel for Aerospace Application by Structural Optimization

    Directory of Open Access Journals (Sweden)

    Naihui Yu

    2015-01-01

    Full Text Available Al-Li alloy and aluminum honeycomb panel (AHP are both excellent materials for aeronautical structures. In this paper, a plate-type aeronautical structure (PAS, which is a base mounting structure for 172 kg functional devices, is selected for comparative analysis with different materials. To compare system-level performance under multidisciplinary constraints, mathematical models for optimization are established and then structural optimization is carried out using Altair OptiStruct. For AHP, its honeycomb core is regarded as orthotropic material and its mechanical properties are calculated by Allen’s model in order to establish finite element model (FEM. The heights of facing sheet and honeycomb core are selected as design variables for size optimization. For Al-Li alloy plate, topology optimization is carried out to obtain its most efficient load path; and then a reconstruction process is executed for practical manufacturing consideration; to obtain its final configuration, accurate size optimization is also used for reconstructed model of Al-Li alloy plate. Finally, the optimized mass and performance of two PASs are compared. Results show that AHP is slightly superior to Al-Li alloy.

  2. Multilayer Clad Plate of Stainless Steel/Aluminum/Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    YUAN Jiawei; PANG Yuhua; LI Ting

    2011-01-01

    The 3, 5, 20 layer clad plate from austenitic stainless steel, pure aluminum and aluminum alloy sheets were fabricated in different ways. The stretch and interface properties were measured. The result shows that 20 layer clad plate is better than the others. Well-bonded clad plate was successfully obtained in the following procedure: Basic clad sheet from 18 layer A11060/A13003sheets was firstly obtained with an initial rolling reduction of 44% at 450 ℃, followed by annealing at 300 ℃, and then with reduction of 50% at 550 ℃ from STS304 on each side. The best 20 layer clad plate was of 129 MPa bonding strength and 225 MPa stretch strength.

  3. Liquid oxygen LOX compatibility evaluations of aluminum lithium (Al-Li) alloys: Investigation of the Alcoa 2090 and MMC weldalite 049 alloys

    Science.gov (United States)

    Diwan, Ravinder M.

    1989-01-01

    The behavior of liquid oxygen (LOX) compatibility of aluminum lithium (Al-Li) alloys is investigated. Alloy systems of Alcoa 2090, vintages 1 to 3, and of Martin Marietta Corporation (MMC) Weldalite 049 were evaluated for their behavior related to the LOX compatibility employing liquid oxygen impact test conditions under ambient pressures and up to 1000 psi. The developments of these aluminum lithium alloys are of critical and significant interest because of their lower densities and higher specific strengths and improved mechanical properties at cryogenic temperatures. Of the different LOX impact tests carried out at the Marshall Space Flight Center (MSFC), it is seen that in certain test conditions at higher pressures, not all Al-Li alloys are LOX compatible. In case of any reactivity, it appears that lithium makes the material more sensitive at grain boundaries due to microstructural inhomogeneities and associated precipitate free zones (PFZ). The objectives were to identify and rationalize the microstructural mechanisms that could be relaxed to LOX compatibility behavior of the alloy system in consideration. The LOX compatibility behavior of Al-Li 2090 and Weldalite 049 is analyzed in detail using microstructural characterization techniques with light optical metallography, scanning electron microscopy (SEM), electron microprobe analysis, and surface studies using secondary ion mass spectrometry (SIMS), electron spectroscopy in chemical analysis (ESCA) and Auger electron spectroscopy (AES). Differences in the behavior of these aluminum lithium alloys are assessed and related to their chemistry, heat treatment conditions, and microstructural effects.

  4. Investigations on dry sliding of laser cladded aluminum bronze

    Directory of Open Access Journals (Sweden)

    Freiße Hannes

    2016-01-01

    Full Text Available The aim of this study was to investigate the tribological behaviour of laser cladded aluminum bronze tool surfaces for dry metal forming. In a first part of this work a process window for cladding aluminum bronze on steel substrate was investigated to ensure a low dilution. Therefore, the cladding speed, the powder feed rate, the laser power and the distance between the process head and the substrate were varied. The target of the second part was to investigate the influence of different process parameters on the tribological behaviour of the cladded tracks. The laser claddings were carried out on both aluminum bronze and cold work tool steel as substrate materials. Two different particle sizes of the cladding powder material were used. The cladding speed was varied and a post-processing laser remelting treatment was applied. It is shown that the tribological behaviour of the surface in a dry oscillating ball-on-plate test is highly dependent on the substrate material. In the third part a deep drawing tool was additively manufactured by direct laser deposition. Furthermore, the tool was applied to form circular cups with and without lubrication.

  5. Evaluation of Corrosion of Aluminum Based Reactor Fuel Cladding Materials During Dry Storage

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, H.B. Jr.

    1999-10-21

    This report provides an evaluation of the corrosion behavior of aluminum cladding alloys and aluminum-uranium alloys at conditions relevant to dry storage. The details of the corrosion program are described and the results to date are discussed.

  6. Electrochemical Codeposition of Al-Li-Mg Alloys at Solid Aluminum Electrode from LiCl-KCl-MgCl2 Molten Salt System

    Science.gov (United States)

    Ye, Ke; Zhang, Mi Lin; Chen, Ye; Han, Wei; de Yan, Yong; Cao, Peng

    2010-06-01

    The electrochemical codeposition of Mg and Li at an aluminium electrode in LiCl-KCl (50:50 wt pct) melts containing different concentrations of MgCl2 at 893 K (620 °C) to form Al-Li-Mg alloys was investigated. Cyclic voltammograms showed that the potential of Li metal deposition at an Al electrode, before the addition of MgCl2, is more positive than that of Li metal deposition at an Mo electrode, which indicated the formation of an Al-Li alloy. The underpotential deposition of magnesium at an aluminium electrode leads to the formation of Al-Mg alloys, and the succeeding underpotential deposition of lithium on predeposited Al-Mg alloys leads to the formation of Al-Li-Mg alloys. Chronopotentiometric measurements indicated that the codeposition of Mg and Li occurs at current densities lower than -0.668 A cm-2 in LiCl-KCl-MgCl2 (8 wt pct) melts at an aluminium electrode. The chronoamperometric studies indicated that the onset potential for the codeposition of Mg and Li is -2.000 V, and the codeposition of Mg and Li at an aluminium electrode is formed into Al-Li-Mg alloys when the applied potentials are more negative than -2.000 V. X-ray diffraction and inductively coupled plasma analysis indicated that Al-Li-Mg alloys with different lithium and magnesium contents were prepared via potentiostatic and galvanostatic electrolysis. The microstructure of typical dual phases of the Al-Li-Mg alloy was characterized by an optical microscope and by scanning electron microscopy. The analysis of energy dispersive spectrometry showed that the elements of Al and Mg distribute homogeneously in the Al-Li-Mg alloy. The lithium and magnesium contents of Al-Li-Mg alloys can be controlled by MgCl2 concentrations and by electrolytic parameters.

  7. A TECHNIQUE FOR IMPROVING THE TOUGHNESS OF Al-Li POWDER METALLURGY ALLOYS

    OpenAIRE

    1987-01-01

    A technique has been developed for increasing the toughness of Al-Li products made by powder metallurgy. The technique which involves the addition of unalloyed aluminum powder to Al-Li powder before compaction was evaluated with Al-Li-Cu-Mg-Zr alloys (Al 8090), and Al-Li-Zn-Cu-Mg-Zr and Al-Li-Mg-Si-Cr alloys . The addition of 15% aluminum to Al 8090 aged at 422K for 40 h produced an increase in impact toughness of 215% at the expense of a drop in yield strength of 11%. The Al-Li-Mg-Si-Cr allo...

  8. Hydrogen diffusion in Al-Li alloys

    Science.gov (United States)

    Anyalebechi, P. N.

    1990-08-01

    The diffusion coefficients of hydrogen in binary Al-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the binary Al-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general form D = DT) where D 0exp(-Q/R is the diffusion coefficient (m2/s), D 0 is the preexponential or frequency factor (m2/s), R is the gas constant (J/K mol), Q is the activation energy (J/mol), and T is absolute temperature (K). The rate of diffusion of hydrogen in aluminum decreases with increase in lithium additions. This is provisionally attributed to the stronger local binding energy between hydrogen and lithium atoms in the aluminum metal lattice.

  9. Evaluation of Pressurization Fatigue Life of 1441 Al-li Fuselage Panel

    Science.gov (United States)

    Bird, R. Keith; Dicus, Dennis I.; Fridlyander, Joseph; Davydov, Valentin

    1999-01-01

    A study was conducted to evaluate the pressurization fatigue life of fuselage panels with skins fabricated from 1441 Al-Li, an attractive new Russian alloy. The study indicated that 1441 Al-Li has several advantages over conventional aluminum fuselage skin alloy with respect to fatigue behavior. Smooth 1441 Al-Li sheet specimens exhibited a fatigue endurance limit similar to that for 1163 Al (Russian version of 2024 Al) sheet. Notched 1441 Al-Li sheet specimens exhibited greater fatigue strength and longer fatigue life than 1163 Al. In addition, Tu-204 fuselage panels fabricated by Tupolev Design Bureau using Al-Li skin and ring frames with riveted 7000-series aluminum stiffeners had longer pressurization fatigue lives than did panels constructed from conventional aluminum alloys. Taking into account the lower density of this alloy, the results suggest that 1441 Al-Li has the potential to improve fuselage performance while decreasing structural weight.

  10. Effect of Temperature and Sheet Temper on Isothermal Solidification Kinetics in Clad Aluminum Brazing Sheet

    Science.gov (United States)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-09-01

    Isothermal solidification (IS) is a phenomenon observed in clad aluminum brazing sheets, wherein the amount of liquid clad metal is reduced by penetration of the liquid clad into the core. The objective of the current investigation is to quantify the rate of IS through the use of a previously derived parameter, the Interface Rate Constant (IRC). The effect of peak temperature and initial sheet temper on IS kinetics were investigated. The results demonstrated that IS is due to the diffusion of silicon (Si) from the liquid clad layer into the solid core. Reduced amounts of liquid clad at long liquid duration times, a roughened sheet surface, and differences in resolidified clad layer morphology between sheet tempers were observed. Increased IS kinetics were predicted at higher temperatures by an IRC model as well as by experimentally determined IRC values; however, the magnitudes of these values are not in good agreement due to deficiencies in the model when applied to alloys. IS kinetics were found to be higher for sheets in the fully annealed condition when compared with work-hardened sheets, due to the influence of core grain boundaries providing high diffusivity pathways for Si diffusion, resulting in more rapid liquid clad penetration.

  11. XRD and TEM analysis of the microstructure in the brazing joint of 3003 cladding aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Tao Feng; Songnian Lou; Luhai Wu; Yajiang Li

    2005-01-01

    The material used in this experiment was 3003 cladding aluminum alloy, the cladding metal was 4004 aluminum alloy.The aluminum plate was brazed by means of vacuum brazing. The microstructure in the brazing joint was studied by means of X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The test result indicates that the suitable brazing technique parameters are brazing temperature, 628℃; keeping time, 10 min; vacuum degree, 6.5×10-4 Pa. XRD test indicates that there are new intermetallic compounds different from the base metal. TEM analysis indicates that Cu2Mg and Cu3Mn2Mg are formed in the brazing joint. The shape of Cu2Mg is irregular and the shape of Cu3Mn2Mg is circle, and there are tiny particles in it.

  12. Protection of spent aluminum-clad research reactor fuels during extended wet storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Stela M.C.; Correa, Olandir V.; Souza, Jose A.; Ramanathan, Lalgudi V., E-mail: lalgudi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Antunes, Renato A. [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Sociais; Ramanathan, Lalgudi V. [Electrocell Ind. Com. Equip. Elet. LTDA (CIETEC), Sao Paulo, SP (Brazil)

    2013-07-01

    Aluminum-clad spent nuclear fuel from research reactors (RR) is stored in light water filled pools or basins worldwide. Many incidences of pitting corrosion of the fuel cladding has been reported and attributed to synergism in the effect of certain water parameters. Protection of spent Al-clad RR fuel with a conversion coating was proposed in 2008. Preliminary results revealed increased pitting corrosion resistance of cerium oxide coated aluminum alloys AA 1050 and AA 6061, used as RR fuel plate cladding. Further development of conversion coatings for Al alloys was carried out and this paper presents: (a) the preparation and characterization of hydrotalcite (HTC) coatings; (b) the results of laboratory tests in which the corrosion behavior of coated Al alloys in NaCl solutions was determined; (c) the results of field tests in which un-coated, boehmite coated, HTC coated and cerium modified boehmite / HTC coated AA 1050 and AA 6061 coupons were exposed to the IEA-R1 reactor spent fuel basin for extended periods. In these field tests the coupons coated with HTC from a high temperature (HT) bath and subsequently modified with Ce were the most resistant to pitting corrosion. In laboratory tests also, HT- hydrotalcite + Ce coated specimens were the most corrosion resistant in 0.01 M NaCl. The role of cerium in increasing the corrosion resistance imparted by the different conversion coatings of spent Al-clad RR fuel elements is presented. (author)

  13. Fabrication of iron aluminum alloy/steel laminate by clad rolling

    Science.gov (United States)

    Masahashi, N.; Watanabe, S.; Hanada, S.; Komatsu, K.; Kimura, G.

    2006-05-01

    Laminates of an iron-aluminum alloy (20Al) and three types of steel—chromium molybdenum (CrMo), high carbon (FeCMn), and precipitation hardening steel with niobium carbide (FeCNb)—were fabricated at 600 °C and 1000 °C by clad rolling based on the compression stress ratio of 20Al to steel. The laminates fabricated at 600 °C exhibit a deformation microstructure with partial recrystallization, while those at 1000 °C reveal a refined microstructure. The 20Al layer of all the laminates exhibit a {001} texture, and the intensity of the texture increases with a decrease in the fabrication temperature and an increase in the reduction. The bending deformability of a laminate increases with a decrease in the compression stress ratio and by a reduction in the intensity of the {001} texture. The clad plate is further rolled at room temperature to a thickness of approximately 150 µm, which enables winding without damage. It is concluded that a high-strength steel at high temperatures and a high Al content in the Fe-Al alloy is beneficial for the fabrication of deformable laminates.

  14. Role of Laser Cladding Parameters in Composite Coating (Al-SiC) on Aluminum Alloy

    Science.gov (United States)

    Riquelme, Ainhoa; Escalera-Rodriguez, María Dolores; Rodrigo, Pilar; Rams, Joaquin

    2016-08-01

    The effect of the different control parameters on the laser cladding fabrication of Al/SiCp composite coatings on AA6082 aluminum alloy was analyzed. A high-power diode laser was used, and the laser control parameters were optimized to maximize the size (height and width) of the coating and the substrate-coating interface quality, as well as to minimize the melted zone depth. The Taguchi DOE method was applied using a L18 to reduce the number of experiments from 81 to only 18 experiments. Main effects, signal-noise ratio and analysis of variance were used to evaluate the effect of these parameters in the characteristics of the coating and to determine their optimum values. The influence of four control parameters was evaluated: (1) laser power, (2) scanning speed, (3) focal condition, and (4) powder feed ratio. Confirmation test with the optimal control parameters was carried out to evaluate the Taguchi method's effectivity.

  15. Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

    Institute of Scientific and Technical Information of China (English)

    孟亮; 田丽

    2002-01-01

    A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al-Li based alloys. The factor values for the Al-Li alloy sheets containing various contents of impurities and cerium addition were evaluated by determining the mechanical properties. It is found that the impurities Fe, Si, Na and K significantly enhance the stress concentration sensitivity of the alloys 2090 and 8090, whereas cerium addition reduces the stress concentration sensitivity to a certain degree for the high strength alloys. However, an excess amount of cerium addition in the high ductility alloy 1420 can significantly increase the stress concentration sensitivity. As compared with conventional aluminum alloys, the Al-Li based alloys generally show high stress concentration sensitivity. Therefore, a special attention must be paid to this problem in the practical application of Al-Li based alloys.

  16. CASTABILITY OF Al-Li-Mg AND Al-Li-Cu-Mg ALLOYS

    OpenAIRE

    1987-01-01

    The objective of the present work is to study the casting characteristics of various Al-Li alloys, which include fluidity and strengths of the alloys and their interaction with cast molds. Materials investigated are Al-Li-Mg and Al-Li-Cu-Mg alloys with Li content of 2.5 wt%. The results show that sand molds with resin binders are good for Al-Li casting. Ceramic coatings can further reduce the metal-mold interactions. However, the permeability is also reduced by coating. The fluidity of Li-bea...

  17. Investigations of Aluminum-Doped Self-Healing Zircaloy Surfaces in Context of Accident-Tolerant Fuel Cladding Research

    Science.gov (United States)

    Carr, James; Vasudevamurthy, Gokul; Snead, Lance; Hinderliter, Brian; Massey, Caleb

    2016-06-01

    We present here some important results investigating aluminum as an effective surface dopant for increased oxidation resistance of zircaloy nuclear fuel cladding. At first, the transport behavior of aluminum into reactor grade zircaloy was studied using simple diffusion couples at temperatures greater than 770 K. The experiments revealed the formation of tens of microns thick graded Zr-Al layers. The activation energy of aluminum in zircaloy was found to be ~175 kJ/mol (~1.8 eV), indicating the high mobility of aluminum in zircaloy. Subsequently, aluminum sputter-coated zircaloy coupons were heat-treated to achieve surface doping and form compositionally graded layers. These coupons were then tested in steam environments at 1073 and 1273 K. The microstructure of the as-fabricated and steam-corroded specimens was compared to those of pure zircaloy control specimens. Analysis of data revealed that aluminum effectively competed with zircaloy for oxygen up until 1073 K blocking oxygen penetration, with no traces of large scale spalling, indicating mechanically stable interfaces and surfaces. At the highest steam test temperatures, aluminum was observed to segregate from the Zr-Al alloy under layers and migrate to the surface forming discrete clusters. Although this is perceived as an extremely desirable phenomenon, in the current experiments, oxygen was observed to penetrate into the zirconium-rich under layers, which could be attributed to formation of surface defects such as cracks in the surface alumina layers.

  18. Characteristics and Application of New Varieties of Copper Clad Aluminum Wire and Copper Clad Steel Wire%铜包铝线和铜包钢线新品种的特性及应用

    Institute of Scientific and Technical Information of China (English)

    王洪丽

    2013-01-01

    The characteristics,applications,product standards,and application technology of the secondarily developed new varieties of copper clad aluminum wire and copper clad steel wire are introduced,including copper clad aluminum enameled wire,tinned copper clad aluminum wire,tinned copper clad steel wire,silver plated copper clad steel wire,so as to provide cable manufacturers and electronic components manufacturers with better choices for cable and electronic materials.%介绍了铜包铝线和铜包钢线二次开发的新品种线材(包括铜包铝漆包线、镀锡铜包铝线、镀锡铜包钢线、镀银铜包钢线)的特性及其应用领域、产品标准和应用技术,以期为线缆厂家及电子元器件厂家提供更好的线缆材料和电子材料的选择.

  19. Utilizing various test methods to study the stress corrosion behavior of Al-Li-Cu alloys

    Science.gov (United States)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1984-01-01

    Recently, much attention has been given to aluminum-lithium alloys because of rather substantial specific-strength and specific-stiffness advantages offered over commercial 2000and 7000-series aluminum alloys. An obstacle to Al-Li alloy development has been inherent limited ductility. In order to obtain a more refined microstructure, powder metallurgy (P/M) has been employed in alloy development programs. As stress corrosion (SC) of high-strength aluminum alloys has been a major problem in the aircraft industry, the possibility of an employment of Al-Li alloys has been considered, taking into account a use of Al-Li-Cu alloys. Attention is given to a research program concerned with the evaluation of the relative SC resistance of two P/M processed Al-Li-Cu alloys. The behavior of the alloys, with and without an addition of magnesium, was studied with the aid of three test methods. The susceptibility to SC was found to depend on the microstructure of the alloys.

  20. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33% was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  1. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-31

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  2. CORROSION OF ALUMINUM CLAD SPENT NUCLEAR FUEL IN THE 70 TON CASK DURING TRANSFER FROM L AREA TO H-CANYON

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2014-06-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 260 {degrees}C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 {degrees}C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  3. Li overlayer formation, oxidation and sputtering characteristics of Al-Li alloys and W/Al-Li composites for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R. (Argonne National Lab., IL (USA)); DeWald, A.B.; Scott, P.; Savage, H. (Corium Industries, Inc., Atlanta, GA (USA))

    1990-01-01

    The next generation of long pulse fusion devices will impose severe requirements on the properties of plasma-facing materials. In devices such as ITER, a divertor design is being considered, using a divertor plate which would be either tungsten or a low-Z material such as graphite or beryllium. Strongly segregating lithium alloys have been proposed as a means of producing a self-sustaining low-Z overlayer which lowers plasma Z{sub eff} and resists self-sputtering. Aluminum-lithium alloys are among the better-characterized lithium-bearing alloys, and it has been demonstrated that lithium segregates strongly in aluminum. However, aluminum has a relatively low melting point, and for low lithium concentrations, the lithium diffusion rate is too slow to replenish lithium at the rate at which it is eroded by the incoming plasma. It has been suggested previously that the superionic {beta} phase Al-Li alloy (48--54 at. % Li) should have high enough diffusivity to be able to replenish surface lithium, and that incorporation of the {beta}-phase AlLi in a composite with tungsten would provide high temperature strength and melt layer stability, along with significantly better thermal conductivity than pure tungsten. Such a composite has been fabricated, as well as a variation containing titanium as a means of controlling oxidation at grain boundaries. The Li overlayer formation, erosion, and replenishment are characterized for the {beta}-phase LiAl alloy, and W-AlLi and W-Ti-AlLi composites. It is found that if there is no oxide layer to inhibit the Li segregation, Li diffusion is extremely rapid, and an oxygen-free Li overlayer is formed which is stable under continuous ion beam sputtering. 21 refs., 7 figs.

  4. IN-SITU SYNTHETIC TiB2 PARTICULATE REINFORCED METAL MATRIX COMPOSITE COATING ON AA2024 ALUMINUM ALLOY BY LASER CLADDING TECHNOLOGY

    OpenAIRE

    JIANG XU; YIDE KAN; WENJIN LIU

    2005-01-01

    In order to improve the wear resistance of aluminum alloy, in-situ synthesized TiB2 and Ti3B4 peritectic composite particulate reinforced metal matrix composite, formed on a 2024 aluminum alloy by laser cladding with a powder mixture of Fe-coated Boron, Ti and Al, was successfully achieved using 3-KW CW CO2 laser. The chemical composition, microstructure and phase structure of the composite clad coating were analyzed by energy dispersive X-ray spectroscopy (EDX), SEM, AFM and XRD. The typical...

  5. Processing and Characterization of Polycrystalline Yag (Yttrium Aluminum Garnet) Core-Clad Fibers - Postprint

    Science.gov (United States)

    2015-01-01

    Nicholas Usechak, Hyun Jun Kim, Santeri Potticary, and Matthew O’Malley Optoelectronics Technology Branch Aerospace Components & Subsystems Division... Aerospace Components & Subsystems Division Air Force Research Laboratory, Sensors Directorate Wright-Patterson Air Force Base, OH 45433-7320 Air Force...clad fiber, ceramic processing 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 8. NUMBER OF PAGES 10 19a. NAME OF

  6. Cladding of aluminum on AISI 304L stainless steel by cold roll bonding: Mechanism, microstructure, and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Akramifard, H.R., E-mail: akrami.1367@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Mirzadeh, H., E-mail: hmirzadeh@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Parsa, M.H., E-mail: mhparsa@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2014-09-08

    The AA1050 aluminum alloy and AISI 304L stainless steel sheets were stacked together to fabricate Al/304L/Al clad sheet composites by the cold roll bonding process, which was performed at temperatures of ∼100 and 23 °C to produce austenitic and austenitic–martensitic microstructures in the AISI 304L counterpart, respectively. The peel test results showed that the threshold reduction required to make a suitable bond at room temperature is below 10%, which is significantly lower than the required reduction for cold roll bonding of Al sheets. The tearing of the Al sheet during the peel test signified that the bond strength of the roll bonded sheets by only 38% reduction has reached the strength of Al, which is a key advantage of the developed sheets. The extrusion of Al through the surface cracks and settling inside the 304L surface valleys due to strong affinity between Al and Fe was found to be the bonding mechanism. Subsequently, the interface and tensile behaviors of three-layered clad sheets after soaking at 200–600 °C for 1 h were investigated to characterize the effect of annealing treatment on the formation and thickening of intermetallic compound layer and the resultant mechanical properties. Field emission scanning electron microscopy, X-ray diffraction, and optical microscopy techniques revealed that an intermediate layer composed mainly of Al{sub 13}Fe{sub 4}, FeC and Al{sub 8}SiC{sub 7} forms during annealing at 500–600 °C. A significant drop in tensile stress–strain curves after the maximum point (UTS) was correlated to the interface debonding. It was found that the formation of intermediate layer by post heat treatment deteriorates the bond quality and encourages the debonding process. Moreover, the existence of strain-induced martensite in clad sheets was found to play a key role in the enhancement of tensile strength.

  7. Vision-based detection of weld pool width in TIG welding of copper-clad aluminum cable

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to realize automatic control of the width of weld pool, a visual sensor system for the width of weld pool detection is developed. By initiative arc light, the image of copper plate weld pool is taken back of the torch through the process of weakening and filtering arc light. In order to decrease the time of processing video signals, analog circuit is applied in the processing where video signals is magnified, trimmed and processed into binary on the datum of dynamic average value, therefore the waveform of video signals of weld pool is obtained. The method that is used for detecting the width of weld pool is established. Results show that the vision sensing method for real-time detecting weld pool width to copper-clad aluminum wire TIG welding is feasible. The response cycle of this system is no more than 50ms, and the testing precision is less than0.1mm.

  8. Alkaline corrosion properties of laser-clad aluminum/titanium coatings

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Herbreteau, Alexis; Rombouts, Marleen

    2015-01-01

    with supersaturated titanium ( (1 weight per cent), Al3Ti intermetallics and large partially undissolved Ti6Al4V particles. Heat treatment lowered the titanium concentration in the aluminum matrix, changed the shape of the Al3Ti precipitates and increased the degree of dissolution of the Ti6Al4V particles. Corrosion...... testing showed significant localized dissolution of the aluminum matrix. Research limitations/implications – Increased titanium concentration and heat treatment gave improved alkaline corrosion properties. At pH 13.5, the Al3Ti phases were protected, while the aluminum matrix corroded. Practical...... implications – For alkaline corrosion-protection of aluminum in the automobile industry, titanium might be useful at pH values below 13.5 or by using other coating techniques. Originality/value – This is the first study testing the use of titanium as a protective element of aluminum in stringent alkaline...

  9. Effects of Thermal Exposure on Properties of Al-Li Alloys

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Stanton, William; Lawless, Kirby; Russell, Carolyn; Wagner, John; Domack, Marcia; Babel, Henry; Farahmand, Bahram; Schwab, David; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    Aluminum-Lithium (Al-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional Al alloys. For example, the application of Al-Li alloy 2195 to the space shuffle external cryogenic fuel tank resulted in weight savings of over 7,000 lb, enabling successful deployment of International Space Station components. The composition and heat treatment of 2195 were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time-dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. Literature surveys have indicated that there is limited thermal exposure data on Al-Li alloys. The effort reported here was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of Al-Li alloys C458, L277, and 2195 in plate gages. Tensile, fracture toughness, and corrosion resistance were evaluated for both parent metal and friction stir welds (FSW) after exposure to temperatures as high as 300 F for up to 1000 hrs. Microstructural changes were evaluated with thermal exposure in order to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Friction stir welds of all alloys showed a drop in elongation with increased length of exposure. Understanding the effect of thermal exposure on the properties and microstructure of Al-Li alloys must be considered in defining service limiting temperatures and exposure times for a reusable cryotank structure.

  10. Effect of continuous induction annealing on the microstructure and mechanical properties of copper-clad aluminum flat bars

    Science.gov (United States)

    Liu, Xin-hua; Jiang, Yan-bin; Zhang, Hong-jie; Xie, Jian-xin

    2016-12-01

    Copper-clad aluminum (CCA) flat bars produced by the continuous casting-rolling process were subjected to continuous induction heating annealing (CIHA), and the effects of induction heating temperature and holding time on the microstructure, interface, and mechanical properties of the flat bars were investigated. The results showed that complete recrystallization of the copper sheath occurred under CIHA at 460°C for 5 s, 480°C for 3 s, or 500°C for 1 s and that the average grain size in the copper sheath was approximately 10.0 μm. In the case of specimens subjected to CIHA at 460-500°C for longer than 1 s, complete recrystallization occurred in the aluminum core. In the case of CIHA at 460-500°C for 1-5 s, a continuous interfacial layer with a thickness of 2.5-5.5 μm formed and the thickness mainly increased with increasing annealing temperature. After CIHA, the interfacial layer consisted primarily of a Cu9Al4 layer and a CuAl2 layer; the average interface shear strength of the CCA flat bars treated by CIHA at 460-500°C for 1-5 s was 45-52 MPa. After full softening annealing, the hardness values of the copper sheath and the aluminum core were HV 65 and HV 24, respectively, and the hardness along the cross section of the CCA flat bar was uniform.

  11. First Principles Study of Al-Li Intermetallic Compounds

    Science.gov (United States)

    Yu, Hai-li; Duan, Xiao-hui; Ma, Yong-jun; Zeng, Min

    2012-12-01

    The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary Al-Li intermetallics, Al3Li, AlLi, Al2Li3, and Al4Li9, are analyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between Al and Li for all the Al-Li intermetallics. In particular, in the Li-rich Al-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration of Li. According to the computational single crystal elastic constants, all the four Al-Li intermetallic compounds considered here are mechanically stable. The polycrystalline elastic modulus and Poisson's ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary Al-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of Al-Li intermetallics decreases in a linear manner.

  12. Fatigue crack growth behaviour of Al-Li alloys

    Science.gov (United States)

    Saravanakumar, R.; Ramakrishna, K. S.; Kanna, B. Avinash

    2013-06-01

    Al-Li alloys are being used in aircraft structures due to its low density and inherent mechanical properties. Fatigue Crack Growth (FCG) resistance is usually high compared to conventional Al-alloys attributed to increased modulus and crack closure. Extensive investigations concern about the FCG resistance and crack closure in Al-Li alloys. The present work reviews the FCG resistance in Al-Li alloys and the mechanisms associated with it. The alloy 8090 is taken for the consideration and sometimes compared with 2024.

  13. First principle calculation of Al, Li and intermetallic compounds for Al-Li system%Al-Li系统性质的第一原理计算

    Institute of Scientific and Technical Information of China (English)

    陈红梅; 范常有; 方杰; 刘奕新; 欧阳义芳; 杜勇; 贺跃辉

    2009-01-01

    用第一原理方法对铝、锂及铝锂二元系统金属间化合物的稳定和亚稳相的原子体积、弹性性质及形成焓等热力学性质进行了计算,结果表明:计算的平均原子体积略大于实验值,计算的体积模量与已有的实验值符合得比较好,对铝锂系统来说,计算的体积模量随锂的浓度的增加单调下降.对铝锂系统的稳定和亚稳定相的形成焓的计算表明,最稳定相为B32结构的Al-Li金属间化合物.%The lattice constants, elastic properties and thermodynamic properties of aluminum, lithium and intermetallic compound for Al-Li system were calculated with density function theo-ry. The calculated lattice constants, elastic constants, isothermal bulk modulus and properties of dimer for aluminum and lithium agree very well with the experimental data. The calculated for-mation enthalpies and isothermal bulk moduli of Al-Li intermetallic compounds are in good agree-ment with the experimental data and the results of other theoretical results available.

  14. High energy X-ray diffraction measurement of residual stresses in a monolithic aluminum clad uranium-10 wt% molybdenum fuel plate assembly

    Science.gov (United States)

    Brown, D. W.; Okuniewski, M. A.; Almer, J. D.; Balogh, L.; Clausen, B.; Okasinski, J. S.; Rabin, B. H.

    2013-10-01

    Residual stresses are expected in monolithic, aluminum clad uranium 10 wt% molybdenum (U-10Mo) nuclear fuel plates because of the large mismatch in thermal expansion between the two bonded materials. The full residual stress tensor of the U-10Mo foil in a fuel plate assembly was mapped with 0.1 mm resolution using high-energy (86 keV) X-ray diffraction. The in-plane stresses in the U-10Mo foil are strongly compressive, roughly -250 MPa in the longitudinal direction and -140 MPa in the transverse direction near the center of the fuel foil. The normal component of the stress is weakly compressive near the center of the foil and tensile near the corner. The disparity in the residual stress between the two in-plane directions far from the edges and the tensile normal stress suggest that plastic deformation in the aluminum cladding during fabrication by hot isostatic pressing also contributes to the residual stress field. A tensile in-plane residual stress is presumed to be present in the aluminum cladding to balance the large in-plane compressive stresses in the U-10Mo fuel foil, but cannot be directly measured with the current technique due to large grain size.

  15. Time-Temperature-Precipitation Behavior in Al-Li Alloy 2195

    Science.gov (United States)

    Chen, P. S.; Bhat, B. N.

    2002-01-01

    Transmission electron microscopy was used to study time-temperature-precipitation (TTP) behavior in aluminum-lithium (Al-Li) 2195 alloy. Al-Li 2195 (nominally Al + 4 percent Cu + 1 percent Li + 0.3 percent Ag + 0.3 percent Mg + 0.1 percent Zr) was initially solutionized for 1 hr at 950 F and then stretched 3 percent. Heat treatments were conducted for up to 100 hr at temperatures ranging from 200 to 1,000 F. TTP diagrams were determined for both matrix and subgrain boundaries. Depending upon heat treatment conditions, precipitate phases (such as GP zone, theta'', theta', theta, delta', T1, TB, and T2) were found in the alloy. The TTP diagrams were applied as a guide to avoid T1 precipitation at subgrain boundaries, as part of an effort to improve the alloy's cryogenic fracture toughness (CFT). New understanding of TTP behavior was instrumental in the development of a two-step artificial aging treatment that significantly enhanced CFT in Al-Li 2195.

  16. Dynamic and kinetic properties of Al-Li melts

    Science.gov (United States)

    Kiselev, A. I.

    2008-12-01

    The dynamic and kinetic properties of Al-Li melts are calculated. The liquid phase of this system is shown to be characterized by three states with different ion distributions and different degrees of electron localization.

  17. Transmission electron microscopy characterization of microstructural features of Al-Li-Cu alloys

    Science.gov (United States)

    Avalos-Borja, M.; Pizzo, P. P.; Larson, L. A.

    1983-01-01

    A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitation events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significant alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations.

  18. Evaluation of aluminum-clad spent fuel corrosion in Argentine basins

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, R.; Loberse, A.N.; Semino, C.J.; Guasp, R. [CNEA, Buenos Aires (Argentina)

    2001-07-01

    An IAEA sponsored Coordinated Research Program was extended to study corrosion effects in several sites. Racks containing Aluminum samples were placed in different positions of each basin and periodic sampling of all the waters was performed to conduct chemical analysis. Different forms of corrosion have been encountered during the programme. In general, the degree of degradation is inversely proportional to the purity of the water. Maximum pit depths after 2 years of exposure are in the range of 100-200 {mu}m. However, sediments deposited on the coupon surfaces seem to be responsible for the developing of large pits (1-2 mm in diameter). In many cases, what appears to be iron oxide particles were found originated by the corrosion of carbon steel components present elsewhere in the basin. These results correlate with observations made on the fuel itself, during exhaustive visual inspection. (author)

  19. Effects of Annealing Process on the Formability of Friction Stir Welded Al-Li Alloy 2195 Plates

    Science.gov (United States)

    Chen, Po-Shou; Bradford, Vann; Russell, Carolyn

    2011-01-01

    Large rocket cryogenic tank domes have typically been fabricated using Al-Cu based alloys like Al-Cu alloy 2219. The use of aluminum-lithium based alloys for rocket fuel tank domes can reduce weight because aluminum-lithium alloys have lower density and higher strength than Al-Cu alloy 2219. However, Al-Li alloys have rarely been used to fabricate rocket fuel tank domes because of the inherent low formability characteristic that make them susceptible to cracking during the forming operations. The ability to form metal by stretch forming or spin forming without excessive thinning or necking depends on the strain hardening exponent "n". The stain hardening exponent is a measure of how rapidly a metal becomes stronger and harder. A high strain hardening exponent is beneficial to a material's ability to uniformly distribute the imposed strain. Marshall Space Flight Center has developed a novel annealing process that can achieve a work hardening exponent on the order of 0.27 to 0.29, which is approximately 50% higher than what is typically obtained for Al-Li alloys using the conventional method. The strain hardening exponent of the Al-Li alloy plates or blanks heat treated using the conventional method is typically on the order of 0.17 to 0.19. The effects of this novel annealing process on the formability of friction stir welded Al-Li alloy blanks are being studied at Marshall Space Flight Center. The formability ratings will be generated using the strain hardening exponent, strain rate sensitivity and forming range. The effects of forming temperature on the formability will also be studied. The objective of this work is to study the deformation behavior of the friction stir welded Al-Li alloy 2195 blank and determine the formability enhancement by the new annealing process.

  20. Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry

    2002-01-01

    Aluminum-Lithium (AL-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional aluminum alloys. For example, the application of an Al-Li alloy to the space shuttle external cryogenic fuel tank contributed to the weight savings that enabled successful deployment of International Space Station components. The composition and heat treatment of this alloy were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. As most aerospace structural hardware is weight sensitive, a reusable cryotank will be designed to the limits of the materials mechanical properties. Therefore, this effort was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of one relatively production mature alloy and two developmental alloys C458 and L277. Tensile and fracture toughness behavior was evaluated after exposure to temperatures as high as 3oooF for up to IO00 hrs. Microstructural changes were also evaluated to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Characterizing the effect of thermal exposure on the properties of Al-Li alloys is important to defining a service limiting temperature, exposure time, and end-of-life properties.

  1. Amorphous Structures in Laser Cladding of ZL111 Aluminum Alloy:Semi-quantitative Study by Differential Thermal Analysis (DTA)

    Institute of Scientific and Technical Information of China (English)

    LI Xianqin; CHENG Zhaogu; XIA Jin'an; XU Guoliang; LIANG Gongying

    2000-01-01

    This paper deals with amorphous structures in the laser cladding. ZL111 alloy is the substrate and Ni-Cr-Al alloy is sprayed on the substrate as the coating material. The coating is clad by a 5 kW transverse flow CO2 laser. The observation of SEM and TEM reveal that in the laser cladding there are amorphous structures of two different morphologies: one is space curved flake-like, and exists in the white web-like structures; the other is fir leaf-like, and exists in the grain-like structures. Differential thermal analysis (DTA) is used to semi-quantitatively determine the content of the amorphous structures. A relation is obtained between the content of amorphous structures and the dimensionless laser cladding parameter C. We also show the changes of the amorphous structures after annealing.

  2. Viscosity and electrical resistivity of Al-Li melts

    Science.gov (United States)

    Kononenko, V. I.; Razhabov, A. A.; Ryabina, A. V.

    2011-08-01

    The kinematic viscosity and electrical resistivity of Al-Li alloys in the liquid state are studied by a combined electrodeless method. Some theoretical calculations performed to determine the viscosity and electrical resistance by comparing the calculated and experimental data are estimated.

  3. Study on electrochemical preparation of Al-Li-Y alloys from Y2O3 in LiCl-KCl-AlCl3 molten salts

    Institute of Scientific and Technical Information of China (English)

    LI Yaming; WANG Fengli; ZHANG Milin; HAN Wei; TIAN Yang

    2011-01-01

    The electrochemical preparaton of Al-Li-Y alloys from LiCl-KCl-A1Cl3-Y2O3 system was studied. The chlorination of Y2O3 by AlCl3 led to the formation of Y (Ⅲ) ions in the molten salts. Cyclic voltammogram (CV) showed that the underpotential deposition (UPD) of yttrium on pre-deposited aluminum caused the formation of Al-Y alloy. Al-Li-Y alloys with different yttriurn contents were obtained by galvanostatic electrolysis and analysed by SEM-EDS and ICP. The ICP results showed that the lithium and yttrium contents in Al-Li-Y alloysdepended on the addition of AlCl3 into the melts.

  4. Modeling-Based Processing of Al-Li Alloys for Delamination Resistance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Al-Li alloys are of interest for use in aerospace structures due to the desirable combination of high strength and low density. However, high strength Al-Li alloys...

  5. Structure-Induced Covalent Bonding in Al-Li Compounds

    Science.gov (United States)

    Nozawa, Kazuki; Ishii, Yasushi

    2010-06-01

    Formation mechanism of a deep pseudogap in the electronic density of states of the Al-Li Bergman and Zintl compounds is discussed with an emphasis on the differences among isostructural Al-Mg compounds. Since Li scatters electrons very weakly in comparison with Al and Mg, the potential landscape for electrons in Al-Li compounds is not that of the entire close-packed structure but that of the Al sublattice, which is a rather porous network like the diamond lattice. The porous network structure realized by the chemical decoration of close-packed structures enhances the covalent nature of electronic structures, hence the deep pseudogap in the electronic density of states. A concept of structure-induced covalent bonding in a network realized by the chemical decoration of close-packed structures may provide a novel picture in the electronic structures of complex intermetallic compounds.

  6. Microstructure and Mechanical Properties of an Al-Li-Mg-Sc-Zr Alloy Subjected to ECAP

    Directory of Open Access Journals (Sweden)

    Anna Mogucheva

    2016-10-01

    Full Text Available The effect of post-deformation solution treatment followed by water quenching and artificial aging on microstructure and mechanical properties of an Al-Li-Mg-Sc-Zr alloy subjected to equal-channel angular pressing (ECAP was examined. It was shown that the deformed microstructure produced by ECAP remains essentially unchanged under solution treatment. However, extensive grain refinement owing to ECAP processing significantly affects the precipitation sequence during aging. In the aluminum-lithium alloy with ultrafine-grained (UFG microstructure, the coarse particles of the S1-phase (Al2LiMg precipitate on high-angle boundaries; no formation of nanoscale coherent dispersoids of the δ′-phase (Al3Li occurs within grain interiors. Increasing the number of high-angle boundaries leads to an increasing portion of the S1-phase. As a result, no significant increase in strength occurs despite extensive grain refinement by ECAP.

  7. The physical metallurgy of mechanically-alloyed, dispersion-strengthened Al-Li-Mg and Al-Li-Cu alloys

    Science.gov (United States)

    Gilman, P. S.

    1984-01-01

    Powder processing of Al-Li-Mg and Al-Li-Cu alloys by mechanical alloying (MA) is described, with a discussion of physical and mechanical properties of early experimental alloys of these compositions. The experimental samples were mechanically alloyed in a Szegvari attritor, extruded at 343 and 427 C, and some were solution-treated at 520 and 566 C and naturally, as well as artificially, aged at 170, 190, and 210 C for times of up to 1000 hours. All alloys exhibited maximum hardness after being aged at 170 C; lower hardness corresponds to the solution treatment at 566 C than to that at 520 C. A comparison with ingot metallurgy alloys of the same composition shows the MA material to be stronger and more ductile. It is also noted that properly aged MA alloys can develop a better combination of yield strength and notched toughness at lower alloying levels.

  8. Micro-, meso- and macro-texture and fatigue crack roughness in Al-Li 2090 T8E41

    Energy Technology Data Exchange (ETDEWEB)

    Haase, J.D.; Guvenilir, A.; Witt, J.R.; Stock, S.R. [Georgia Inst. of Tech., Atlanta, GA (United States)

    1998-12-31

    The use of synchrotron polychromatic x-ray microbeams in the transmission geometry is described for mapping grain orientation as a function of position and for relating this microtexture to the formation of large asperities on fatigue crack surfaces in Al-Li 2090 T8E41. In common with the centers of rolled plates of many aluminum alloys, Al-Li 2090 T8E41 has a sharp average texture or macrotexture different from that in the outer portions of the plate. The geometry of large asperities in Al-Li 2090 has been related to this macrotexture, and the resulting roughness-induced crack closure is recognized to be responsible for the very low crack propagation rates in certain plate orientations. This report focuses on why asperities form at certain positions and why the crack remains relatively planar elsewhere. The microtexture (i.e., the grain-to-grain orientation variation) seems to be organized into a specific type of mesotexture: multiple adjacent grains have nearly identical orientations and form substantial volumes of near-single-crystal material. Transitions between differently oriented near-single-crystal volumes or between a near-single-crystal region and more randomly oriented grains appear to bound asperities.

  9. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    Science.gov (United States)

    Wang, Hong; Wang, Jy-An John

    2016-10-01

    Behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending was studied. Tests were performed under load or moment control at 5 Hz. The surrogate rods fractured under moment amplitudes greater than 10.16 Nm with fatigue lives between 2.4 × 103 and 2.2 × 106 cycles. Fatigue response of Zry-4 cladding was characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition affect surrogate rod failure. Both debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. The effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective gauge length is effective in sensor spacing correction. The database developed and the understanding gained in this study can serve as input to analysis of SNF (spent nuclear fuel) vibration integrity.

  10. Microstructural characterization of an Al-li-mg-cu alloy by correlative electron tomography and atom probe tomography.

    Science.gov (United States)

    Xiong, Xiangyuan; Weyland, Matthew

    2014-08-01

    Correlative electron tomography and atom probe tomography have been carried out successfully on the same region of a commercial 8090 aluminum alloy (Al-Li-Mg-Cu). The combination of the two techniques allows accurate geometric reconstruction of the atom probe tomography data verified by crystallographic information retrieved from the reconstruction. Quantitative analysis of the precipitate phase compositions and volume fractions of each phase have been obtained from the atom probe tomography and electron tomography at various scales, showing strong agreement between both techniques.

  11. 采用铜铝复合管的翅片管换热器性能试验研究%Experimental research on substitute of aluminum clad copper tube in finned tube heat exchanger

    Institute of Scientific and Technical Information of China (English)

    金听祥; 曹玉龙

    2012-01-01

    针对铜铝复合管(ACC管)在空调用翅片管换热器中替代铜管应用进行了试验研究.分别对Φ7.94mm型管的全铜管、过冷段铜铝复合管、全铜铝复合管三种换热器进行了性能比较和成本分析.研究结果表明,在风速和风量不变的情况下,过冷段铜铝复合管换热器能力为8634.22W,高于全铜铝复合管的换热器的8389.36W,低于全铜管换热器的8989.07W.制冷剂侧能力测试中,过冷段铜铝复合管换热器平均值为8.885kW,与全铜铝复合管换热器平均值8.775kW相比高1.24%,与全铜管换热器平均值9.101kW相比低2.37%,与能力测试结果基本一致.与原换热器铜管相比,在相同条件下,铜铝复合管可以降低管材成本29.5%.综上所述,过冷段采用铜铝复合管的换热器能够取代铜管换热器应用在空调中,在不影响其换热性能的基础上,降低成本效果明显.%In this paper, the aluminum clad copper tube was investigated to replace copper tube as finned tube heat exchanger. The heat transfer performance and cost of three types of finned tube heat exchangers adopting copper tube, subcooled portion with aluminum clad copper lube and all aluminum clad copper tube with φ7. 94mm diameter were compared. The experimental results show that with the same wind speed and air volume, the capacity of the heat exchanger with aluminum clad copper tube in subcooled portion in air side is 8634.22W, higher than that of the heat exchanger with all aluminum clad copper tube, and lower than that of the heat exchanger with copper tube. Meanwhile, the capacity of the heat exchanger with aluminum clad copper tube in subcooled portion in the refrigerant side is 8. 885kW, which is 1.24% higher than that of the heat exchanger with all aluminum clad copper tube and 2. 37% lower than that of the heat exchanger with copper tube. At the same conditions, the costs of a-luminum clad copper tube can be reduced 29.5% compared with copper tube. In

  12. Microstructural characterization of rapidly solidified Al-Li-Co powders

    Science.gov (United States)

    Samuel, Fawzy H.

    1986-01-01

    A study of the combined effect of alloying elements and melt superheat has been carried out on the as-solidified structure of rapidly solidified Al-Li-Co powders. Three alloys, viz., Al-3 pct Li, Al-3 pct Li-0.4 pct Co, and Al-3 pct Li-0.8 pct Co were chosen, and the liquid melt in each alloy atomized from the temperatures 1173 and 1073 K, using the centrifugal atomization technique. The microstructural characterization was done using light, scanning, and transmission electron microscopy. Four types of microstructures, viz., dendritic, cellular, equiaxed-type, and featureless structures, were observed by light microscopy. The cooling rate, as determined from the same, lay in the range 104 to 106 Ks-1, but was seen to go beyond 107 Ks-1 when estimated from TEM micrographs. On the micro-level, the Al-Li powders were found to exhibit dendritic structures with differing morphologies, whereas low-angle cell walls with perturbed interfaces were the main structural features observed in the Al-Li-Co alloys. Increasing both cobalt content and powder particle diameter favored transition from dendritic into cellular structure. The featureless zone was comprised mainly of elongated columnar grains (0.2 μm width and 1.5 μm length). A mechanism describing the cellular structure formation has been proposed. Aging of the melt-quenched powders at 473 K for times up to 100 hours results in the dissolution of the cellular structure. A mechanism for the same has been postulated. The difference in the superheats chosen in the present work is found not sufficient to cause drastic microstructural changes.

  13. A comparative wear study on Al-Li and Al-Li/SiC composite

    Science.gov (United States)

    Okumus, S. Cem; Karslioglu, Ramazan; Akbulut, Hatem

    2013-12-01

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms-1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  14. Fatigue Crack Growth Rate Test Results for Al-Li 2195 Parent Metal, Variable Polarity Plasma Arc Welds and Friction Stir Welds

    Science.gov (United States)

    Hafley, Robert A.; Wagner, John A.; Domack, Marcia S.

    2000-01-01

    The fatigue crack growth rate of aluminum-lithium (Al-Li) alloy 2195 plate and weldments was determined at 200-F, ambient temperature and -320-F. The effects of stress ratio (R), welding process, orientation and thickness were studied. Results are compared with plate data from the Space Shuttle Super Lightweight Tank (SLWT) allowables program. Data from the current series of tests, both plate and weldment, falls within the range of data generated during the SLWT allowables program.

  15. Fracture toughness of an Al-Li-Cu-In alloy

    Science.gov (United States)

    Wagner, John A.; Gangloff, Richard P.

    1992-01-01

    The crack initiation and growth fracture toughness of select AL-Li-Cu alloy variants are characterized and elucidated. Conventionally processed plates form large DC cast ingots are investigated to eliminate the variation in microstructure associated with laboratory scale and SPF-processed material. Fracture resistance is characterized using the J-integral method to establish crack initiation and growth behavior at 25 and -185 C. It is shown that state-of-the-art 2090-T81 has superior toughness compared to 2090 + In-T6 at both test temperatures, with the low toughness of 2090 + In-T6 associated with intersubgranular fracture attributed to a high density of subboundary precipitates.

  16. Al-Li Alloy 1441 for Fuselage Applications

    Science.gov (United States)

    Bird, R. K.; Dicus, D. L.; Fridlyander, J. N.; Sandler, V. S.

    2000-01-01

    A cooperative investigation was conducted to evaluate Al-Cu-Mg-Li alloy 1441 for long service life fuselage applications. Alloy 1441 is currently being used for fuselage applications on the Russian Be-103 amphibious aircraft, and is expected to be used for fuselage skin on a new Tupolev business class aircraft. Alloy 1441 is cold-rollable and has several attributes that make it attractive for fuselage skin applications. These attributes include lower density and higher specific modulus with similar strength as compared to conventional Al-Cu-Mg alloys. Cold-rolled 1441 Al-Li sheet specimens were tested at NASA Langley Research Center (LaRC) and at the All-Russia Institute of Aviation Materials (VIAM) in Russia to evaluate tensile properties, fracture toughness, impact resistance, fatigue life and fatigue crack growth rate. In addition, fuselage panels were fabricated by Tupolev Design Bureau (TDB) using 1441 skins and Al-Zn-Mg-Cu alloy stiffeners. The panels were subjected to cyclic pressurization fatigue tests at TDB and at LaRC to simulate fuselage pressurization/depressurization during aircraft service. This paper discusses the results from this investigation.

  17. Oxide-cladding aluminum nitride photonic crystal slab: Design and investigation of material dispersion and fabrication induced disorder

    Energy Technology Data Exchange (ETDEWEB)

    Melo, E. G., E-mail: emerdemelo@usp.br; Alvarado, M. A.; Carreño, M. N. P.; Alayo, M. I. [Electronic Systems Engineering Department, University of São Paulo, CEP 05508-010 São Paulo, SP (Brazil); Carvalho, D. O. [UNESP - São Paulo State University, CEP 13874-149 São João da Boa Vista, SP (Brazil); Ferlauto, A. S. [Department of Physics, Federal University of Minas Gerais, CEP 31270-901 Belo Horizonte, MG (Brazil)

    2016-01-14

    Photonic crystal slabs with a lower-index material surrounding the core layer are an attractive choice to circumvent the drawbacks in the fabrication of membranes suspended in air. In this work we propose a photonic crystal (PhC) slab structure composed of a triangular pattern of air holes in a multilayer thin film of aluminum nitride embedded in silicon dioxide layers designed for operating around 450 nm wavelengths. We show the design of an ideal structure and analyze the effects of material dispersion based on a first-order correction perturbation theory approach using dielectric functions obtained by experimental measurements of the thin film materials. Numerical methods were used to investigate the effects of fabrication induced disorder of typical nanofabrication processes on the bandgap size and spectral response of the proposed device. Deviation in holes radii and positions were introduced in the proposed PhC slab model with a Gaussian distribution profile. Impacts of slope in holes sidewalls that might result from the dry etching of AlN were also evaluated. The results show that for operation at the midgap frequency, slope in holes sidewalls is more critical than displacements in holes sizes and positions.

  18. Assessment of Al-Li Alloys for Cryotanks

    Science.gov (United States)

    Babel, Henry W.; Bozich, William; Farahmand, Bob; DeJesus, Ron; Sankaran, K. K.; Schwab, Dave; Tarkanian, Mike; Funk, Joan G. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on steps undertaken to determine the suitability of Aluminum and Lithium alloys in cryogenic tank construction. Major characteristics are offered for several different candidate alloys including reliability, weldability, flammability, and required thicknesses.

  19. Hot Isostatic Press Can Optimization for Aluminum Cladding of U-10Mo Reactor Fuel Plates: FY12 Final Report and FY13 Update

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffield, Andrew N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weinberg, Richard Y. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hudson, Richard W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mihaila, Bogdan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Liu, Cheng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lovato, Manuel L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-08-26

    Currently, the proposed processing path for low enriched uranium – 10 wt. pct. molybdenum alloy (LEU-10Mo) monolithic fuel plates for high power research and test reactors includes hot isostatic pressing (HIP) to bond the aluminum cladding that encapsulates the fuel foil. Initial HIP experiments were performed at Idaho National Laboratory (INL) on approximately ¼ scale “mini” fuel plate samples using a HIP can design intended for these smaller experimental trials. These experiments showed that, with the addition of a co-rolled zirconium diffusion barrier on the LEU-10Mo alloy fuel foil, the HIP bonding process is a viable method for producing monolithic fuel plates. Further experimental trials at Los Alamos National Laboratory (LANL) effectively scaled-up the “mini” can design to produce full-size fuel prototypic plates. This report summarizes current efforts at LANL to produce a HIP can design that is further optimized for higher volume production runs. The production-optimized HIP can design goals were determined by LANL and Babcock & Wilcox (B&W) to include maintaining or improving the quality of the fuel plates produced with the baseline scaled-up mini can design, while minimizing material usage, improving dimensional stability, easing assembly and disassembly, eliminating machining, and significantly reducing welding. The initial small-scale experiments described in this report show that a formed-can approach can achieve the goals described above. Future work includes scaling the formed-can approach to full-size fuel plates, and current progress toward this goal is also summarized here.

  20. Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products

    Science.gov (United States)

    Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry

    2003-01-01

    The objective of this viewgraph representation is to evaluate the effects of thermal exposure on the mechanical properties of both production mature and developmental Al-Li alloys. The researchers find for these alloys, the data clearly shows that there is no deficit in mechanical properties at lower exposure temperatures in some cases, and a signficant deficit in mechanical properties at higher exposure temperatures in all cases. Topics considered include: Al-Li alloys composition, key characteristics of Al-Li alloys and thermal exposure matrix.

  1. Continuous Cast Forming Machine with Vertical Core-Filling for Copper Cladding Aluminum Composite Bars%铜包铝复合扁排立式充芯连铸设备的研制

    Institute of Scientific and Technical Information of China (English)

    张建宇; 王屹峰; 万长清; 曾祥勇; 蔡鹏; 吴春京

    2013-01-01

    A new continuous core-filling casting machine for copper cladding aluminum composite bars was designed and produced. The machine installed the upper and bottom graphite crucibles in the vertical direction for heating inner core of aluminum and the outer layer of copper. During continuous casting, copper tube was formed in the crystallizer continuously firstly, then liquid aluminum was injected into the copper tube through mandrel. Finally, the metallurgical bonded layer was formed by inter-diffusion between copper and aluminum. The copper cladding aluminum composite bars with the core thickness of 10 mm and the sheath thickness of 2 mm and the width of 60 mm were fabricated successfully by the machine.%设计和制造了一台制备铜包铝复合扁排的立式充芯连铸试验设备,该设备的特点是在高度方向上设置上下两个加热坩埚分别熔化铜和铝;外层铜管在结晶器中首先形成,铝液随之通过充芯管充填到铜管中,铜、铝界面通过互扩散实现冶金结合.利用此设备,成功地连铸出铜层厚度为2 mm,芯部铝厚度为10 mm,宽为60 mm的铜包铝复合扁排.

  2. Investigation of laser cladding Cu/Cr Alloy on AA6061 Aluminum%AA6061铝基材上激光熔覆Cu/Cr合金层的研

    Institute of Scientific and Technical Information of China (English)

    丁健君; 郑恢俊

    2001-01-01

    在易氧化的纯Al表面制备Cu/Cr合金熔覆层,因二者的熔点温度差别大且容易在结合过渡区产生脆性裂纹而有一定难度。本文通过扫描电镜(SEM)分析研究了激光工艺参数对Cu/Cr熔覆层过渡区裂纹倾向的影响。实验结果表明,以1.06μm波长的Nd:YAG激光器的聚焦光束为热源,通过选择合适的激光工艺参数,可获得理想的Cu/Cr合金熔覆层,这对于改进铝材表面的物理、化学性能并进一步开发其作为电接触材料具有应用价值。%The laser cladding Cu/Cr alloy layers on commercial pure aluminum AA6061 which exposed to the atmosphere rapidly oxidizes,it is hardly to deal with since their melting points are quite different and the cracks are easily induced in the bound zone of cladding layers.This paper investigated the influences of laser process parameters on cracking trend in the bound zone by means of scanning electron microscope (SEM).The results indicate:the Cu/Cr cladding layers with pores and crack free can be prepared on Al substrates by the focusing Nd:YAG laser beam as a heating source under suitable laser process parameters,which is very useful to improve the surface properties of aluminum and furthermore to spread the applied values of aluminum as the electronic contacts.

  3. The Evolution of Al-Li Base Products for Aerospace and Space Applications

    Science.gov (United States)

    Rioja, Roberto J.; Liu, John

    2012-09-01

    A technical review of the physical, mechanical, and metallurgical variables that have influenced performance of Al-Li based alloys over the last 50 years is presented. First, the historic evolution of different alloys is discussed. Then, the microstructural features responsible for different mechanical properties are identified and discussed. The role of alloying additions is discussed. The shortcomings of a 2nd generation Al-Li alloys are introduced and the key alloy design principles used to overcome these are discussed. Finally, the performance parameters that play a major role in sizing several aircraft and space craft components are reviewed in a chronological perspective and compared with 3rd-generation Al-Li alloys. It is concluded that significant improvements have been made to position Al-Li alloys to enable improved performance of next generation of air and space craft.

  4. Influence of alloying elements on mechanical properties of Al-Li plates

    Institute of Scientific and Technical Information of China (English)

    杨守杰; 戴圣龙; 苏彬; 颜鸣皋

    2004-01-01

    The effect of alloying elements such as Cu, Mn and Zr on the mechanical properties of the Al-Li plates was studied, and the grain structure, crystallographic texture and precipitates were also investigated. It is found that the element Zr has a two-fold effect on the anisotropy of mechanical properties; the addition of element Mn can reduce the crystalline texture and the anisotropy of Al-Li plates. However, the effect of Cu element appears less pronounced.

  5. [Determination of hydrogen in 2,091 Al-Li alloy].

    Science.gov (United States)

    Wang, X; Yang, Y

    2000-02-01

    High volatility element Li exists in 2091 Al-Li alloy, and makes the difficulty for the determination of hydrogen. A lot of tests were done, for example, how to distinguish the body and surface hydrogen, to choice heating power, heating time and the size of sample. Then the analytical method is established and many discussions were done. The reproducibility and accuracy is satisfactory, and compared with the Russian Al-Li alloy hydrogen standard sample.

  6. Environmental fatigue of an Al-Li-Cu alloy. Part 2: Microscopic hydrogen cracking processes

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1992-01-01

    Based on a fractographic analysis of fatigue crack propagation (FCP) in Al-Li-Cu alloy 2090 stressed in a variety of inert and embrittling environments, microscopic crack paths are identified and correlated with intrinsic da/dN-delta K kinetics. FCP rates in 2090 are accelerated by hydrogen producing environments (pure water vapor, moist air, and aqueous NaCl), as defined in Part 1. For these cases, subgrain boundary fatigue cracking (SGC) dominates for delta K values where the crack tip process zone, a significant fraction of the cyclic plastic zone, is sufficiently large to envelop 5 micron subgrains in the unrecrystallized microstructure. SGC may be due to strong hydrogen trapping at T1 precipitates concentrated at sub-boundaries. At low delta K, the plastic zone diameter is smaller than the subgrain size and FCP progresses along (100) planes due to either local lattice decohesion or aluminum-lithium hydride cracking. For inert environments (vacuum, helium, and oxygen), or at high delta K where the hydrogen effect on da/dN is small, FCP is along (111) slip planes; this mode does not transition with increasing delta K and plastic zone size. The SGC and (100) crystallographic cracking modes, and the governing influence of the crack tip process zone volume (delta K), support hydrogen embrittlement rather than a surface film rupture and anodic dissolution mechanism for environmental FCP. Multi-sloped log da/dN-log delta K behavior is produced by changes in process zone hydrogen-microstructure interactions, and not by purely micromechanical-microstructure interactions, in contradiction to microstructural distance-based fatigue models.

  7. Additive manufacturing of metal alloy for aerospace by means of Powder Laser Cladding: station tuning and clad characterization

    OpenAIRE

    Fierro, Ilaria

    2016-01-01

    2014 - 2015 This thesis investigates the application of continuous coaxial laser cladding by powder injection as repair and cover process. The investigation aimed to check the possibility of repairing a V-groove geometry on a substrate of AA2024 and A357 aluminum alloy. Chapter one is an introduction to the laser cladding. This presents a general overview of the laser cladding methods and some applications for the processes. In the second chapter, the laser cladding process is analys...

  8. Effect of aging in an electric field on microstructures and properties of 1420 Al- Li alloy

    Institute of Scientific and Technical Information of China (English)

    刘北兴; 李洪涛; 覃耀春; 冯海波

    2002-01-01

    After solution treatment, the 1420 Al- Li alloy samples were aged at different temperatures in an e-lectric field with different intensity. The measurements made showed that the electric field increased the strengthofthe 1420 Al -Li alloy, and best properties were obtained when they were aged at 120 ℃ with E = 4 kV/cmfor 12 hrs. The electric field promoted the nucleation ofδ' phase, increased the quantity of the δ' phase, andmade the size of the δ' phase particles smaller. The electric field restrained the formation and growth of PFZ,and increased the intensity of the electric field while the width of the PFZ was decreased.

  9. EBSD and Nanoindentation-Correlated Study of Delamination Fracture in Al-Li Alloy 2090

    Science.gov (United States)

    Tayon, Wesley A.; Crooks, Roy E.; Domack, Marcia S.; Wagner, John A.; Elmustafa, A. A.

    2008-01-01

    Al-Li alloys offer attractive combinations of high strength and low density. However, a tendency for delamination fracture has limited their use. A better understanding of the delamination mechanisms may identify methods to control delaminations through processing modifications. A combination of new techniques has been used to evaluate delamination fracture in Al-Li alloys. Both high quality electron backscattered diffraction (EBSD) information and valid nanoindentation measurements were obtained from fractured test specimens. Correlations were drawn between nano-scale hardness variations and local texture along delaminating boundaries. Intriguing findings were observed for delamination fracture through the combined analysis of grain orientation, Taylor factor, and kernel average misorientation.

  10. Built-up Al-Li structures for cryogenic tank and dry bay applications

    Science.gov (United States)

    Lisagor, W. Barry

    1993-02-01

    The objectives are: (1) to demonstrate the cost benefits of built-up cryotank and dry bay structures; (2) to study of benefits of using Al alloys; (3) to study of benefit of using Al-Li alloys; (4) to evaluate alternative low-cost stiffener and joining concepts.

  11. Dislocation Dynamics in Al-Li Alloys. Mean Jump Distance and Activation Length of Moving Dislocations

    NARCIS (Netherlands)

    Hosson, J.Th.M. De; Huis in 't Veld, A.; Tamler, H.; Kanert, O.

    1984-01-01

    Pulsed nuclear magnetic resonance proved to be a complementary new technique for the study of moving dislocations in Al-Li alloys. The NMR technique, in combination with transmission electron microscopy and strain-rate change experiments have been applied to study dislocation motion in Al-2.2 wt% Li

  12. Built-up Al-Li structures for cryogenic tank and dry bay applications

    Science.gov (United States)

    Lisagor, W. Barry

    1993-01-01

    The objectives are: (1) to demonstrate the cost benefits of built-up cryotank and dry bay structures; (2) to study of benefits of using Al alloys; (3) to study of benefit of using Al-Li alloys; (4) to evaluate alternative low-cost stiffener and joining concepts.

  13. Segregation Study of the β phase on the Al-Li Alloy Surface using Auger Electron Spectroscopy

    Science.gov (United States)

    Belkhiat, S.; Keraghel, F.

    2009-11-01

    Auger Electron spectroscopy (AES) has been used to study lithium segregation on Al-3.49wt%-Li alloy surface. In this work, the surface atomic composition as a function of temperature was followed. In our previous works, the activation energy of Li segregation has been determined experimentally being in agreement with the resulted theoretical value. In this paper, one showed that the segregation energy of Li on the surface depends of the crystalline structure and of the Li content in the Al-Li alloy matrix. β-AlLi phase on the alloy surface, used in the power sources for the propulsion of electrical vehicles and for stocking energy, is obtained by progressive heating. We showed that the segregated lithium on the alloy surface is reversible as a function of decreasing temperature and consequently β-AlLi phase is converted in α-AlLi phase. On the other hand, the brutal heating of the sample drives to the conversion of the α-AlLi phase to β-AlLi phase and stabilizes the surface towards other segregation; therefore the conversion of β-AlLi phase to α-AlLi phase is irreversible.

  14. Prediction of forming limit curve (FLC) for Al-Li alloy 2198-T3 sheet using different yield functions

    Institute of Scientific and Technical Information of China (English)

    Li Xiaoqiang; Song Nan; Guo Guiqiang; Sun Zhonggang

    2013-01-01

    The Forming Limit Curve (FLC) of the third generation aluminum-lithium (Al-Li) alloy 2198-T3 is measured by conducting a hemispherical dome test with specimens of different widths. The theoretical prediction of the FLC of 2198-T3 is based on the M-K theory utilizing respectively the von Mises, Hill’48, Hosford and Barlat 89 yield functions, and the different predicted curves due to different yield functions are compared with the experimentally measured FLC of 2198-T3. The results show that though there are differences among the four predicted curves, yet they all agree well with the experimentally measured curve. In the area near the planar strain state, the predicted curves and experimentally measured curve are very close. The predicted curve based on the Hosford yield function is more accurate under the tension-compression strain states described in the left part of the FLC, while the accuracy is better for the predicted curve based on Hill’48 yield function under the tension-tension strain states shown in the right part.

  15. Investigation of Abnormal Grain Growth in a Friction Stir Welded and Spin-Formed Al-Li Alloy 2195 Crew Module

    Science.gov (United States)

    Tayon, Wesley A.; Domack, Marcia S.; Hoffman, Eric K.; Hales, Stephen J.

    2013-01-01

    In order to improve manufacturing efficiency and reduce structural mass and costs in the production of launch vehicle structures, NASA is pursuing a wide-range of innovative, near-net shape manufacturing technologies. A technology that combines friction stir welding (FSW) and spin-forming has been applied to manufacture a single-piece crew module using Aluminum-Lithium (AL-Li) Alloy 2195. Plate size limitations for Al-Li alloy 2195 require that two plates be FSW together to produce a spin-forming blank of sufficient size to form the crew module. Subsequent forming of the FSW results in abnormal grain growth (AGG) within the weld region upon solution heat treatment (SHT), which detrimentally impacts strength, ductility, and fracture toughness. The current study seeks to identify microstructural factors that contribute to the development of AGG. Electron backscatter diffraction (EBSD) was used to correlate driving forces for AGG, such as stored energy, texture, and grain size distributions, with the propensity for AGG. Additionally, developmental annealing treatments prior to SHT are examined to reduce or eliminate the occurrence of AGG by promoting continuous, or uniform, grain growth

  16. Effect of Rare Earth Elements on Anisotropy and Microstructure of Al-Li Alloy 2195 Sheets

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For the purpose of decreasing the applied limitation resulting from the anisotropic mechanical property of Al-Li alloy 2195, this study employed a complex heat treatment process, involving the pre-tension, thermo-infiltration of the rare earth element Ce, solution treatment, and artificial aging technology. The results indicate that the infiltration of rare earth element Ce benefits the abatement of anisotropy of Al-Li alloy 2195 sheet, in contrast with that of the normal heat treatment process. The gradient of the Vickers-hardness decreases at least 50% through the thickness, and the tensile strength in the rolling direction also increases significantly. If Ce was infiltrated into the alloy under the optimum pre-deformation, the yield strength (σ0.2) increased by 30 MPa while the tensile strength (σb) enhanced by 25 MPa compared to the rare earth free samples. Meanwhile, the fractography illustrated that the fracture surface of the sample became more desirable.

  17. Study on Damage of High Temperature Plastic Deformation for Al-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The security of use for Al-Li alloy will be greatly influenced by the damage degree of plastic deformation within it at high temperature . Based on continuum damage mechanics theory, the damage evolution of Al-5.44Mg-2.15Li-0.12Zr alloy during plastic deforming at high temperature is simulated by using the damage evolution model of high temperature plastic deformation. The changing rule of its inner damage with deformation temperature, strain rate and strain is gained in this paper. The equation of damage evolution for high temperature plastic deformation is developed, providing an academic basis for the technology of plastic process of Al-Li alloys.

  18. Composition and corrosion resistance of cerium conversion films on 2195Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    SONG Dong; FENG Xingguo; SUN Mingren; MA Xinxin; TANG Guangze

    2012-01-01

    The Ce conversion films on 2195Al-Li alloy without and with post-treatment were studied and the corrosion resistance was evaluated as well.The surface morphology was observed by scanning electron microscopy (SEN),and the chemical composition was characterized by X-ray photoelectron spectroscopy (XPS).The corrosion behaviors of 2195Al-Li alloy and conversion coating were assessed by means of potentiodynamic polarization curves.The experimental results indicated that after post-treatment the surface quality was improved significantly.According to XPS,the conversion coating after post-treatment was mainly composed of CeO2,Ce2O3,Ce-OH and a little MoO3 and MoO2.The results of potentiodynamic polarization curves revealed that the conversion coating with post-treatment possessed better corrosion resistance than bare alloy and Ce conversion coating without post-treatment.

  19. ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY DURING CORROSION PROCESS OF 8090 Al-Li ALLOY IN EXCO SOLUTION

    Institute of Scientific and Technical Information of China (English)

    J.F. Li; Z.Q. Zheng; C.Y. Tan; S.C. Li; Z. Zhang; J.Q. Zhang

    2004-01-01

    The corrosion behavior and electrochemical impedance spectroscopy ( EIS) features of 8090 Al-Li alloys in EXCO solution were investigated, and the EIS was simulated using an equivalent circuit. At the beginning of immersion in EXCO solution, the EIS is comprised by a depressed capacitive arc at high-mediate frequency and an inductive arc at low frequency, and the inductive component decreases and disappears with immersion time. Once exfoliation or severe pitting corrosion is produced, two capacitivearcs appear in the EIS. These two capacitive arcs are originated from the two parts of the corroded alloy surface, the original flat alloy surface and the new inter-face exposed to the aggressive EXCO solution due to the exfoliation or pitting corrosion.Some corrosion development features of 8090 Al-Li alloys in EXCO solution can be obtained through simulated EIS information.

  20. Cryogenic mechanical properties of low density superplastically formable Al-Li alloys

    Science.gov (United States)

    Verzasconi, S. L.; Morris, J. W., Jr.

    1989-01-01

    The aerospace industry is considering the use of low density, superplastically formable (SPF) materials, such as Al-Li alloys in cryogenic tankage. SPF modifications of alloys 8090, 2090, and 2090+In were tested for strength and Kahn tear toughness. The results were compared to those of similar tests of 2219-T87, an alloy currently used in cryogenic tankage, and 2090-T81, a recently studied Al-Li alloy with exceptional cryogenic properties (1-9). With decreasing temperature, all materials showed an increase in strength, while most materials showed an increase in elongation and decrease in Kahn toughness. The indium addition to 2090 increased alloy strength, but did not improve the strength-toughness combination. The fracture mode was predominantly intergranular along small, recrystallized grains, with some transgranular fracture, some ductile rupture, and some delamination on large, unrecrystallized grains.

  1. Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

    Science.gov (United States)

    Trybula, Marcela; Gancarz, Tomasz; Gasior, Wladyslaw; Pasturel, Alain

    2014-11-01

    Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A 1 B 2 and A 2 B 3 clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.

  2. Aqueous sodium chloride induced intergranular corrosion of Al-Li-Cu alloys

    Science.gov (United States)

    Pizzo, P. P.; Daeschner, D. L.

    1986-01-01

    Two methods have been explored to assess the susceptibility of Al-Li-Cu alloys to intergranular corrosion in aqueous sodium chloride solution. They are: (1) constant extension rate testing with and without alternate-immersion preexposure and (2) metallographic examination after exposure to a NaCl-H2O2 corrosive solution per Mil-H-6088F. Intergranular corrosion was found to occur in both powder and ingot metallurgy alloys of similar composition, using both methods. Underaging rendered the alloys most susceptible. The results correlate to stress-corrosion data generated in conventional time-to-failure and crack growth-rate tests. Alternate-immersion preexposure may be a reliable means to assess stress corrosion susceptibility of Al-Li-Cu alloys.

  3. A new high strength and high tolerance-resistance Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Shou-jie; LU Zheng; DAI Sheng-long; HAN Ya-fang; YAN Ming-gao

    2006-01-01

    In order to develop a new high strength and high tolerance-resistance Al-Li alloy which can be used in aerospace industry,the effects of microalloying elements such as Mg, Ag, Mn and Zn on the mechanical properties of Al-Cu-Li alloys were studied. The results show that the strengthening effects of Mg+Ag and Mg+Zn additions are higher than those of the individual Mg, Ag or Zn addition. The element Mn can also bring some extent strengthening effects on the alloys, but it has nothing to do with the other microalloying elements present or not. Finally, a new Al-Li alloy with Mg+Zn+Mn additions was developed, which possesses high strength and high tolerance-resistance promising properties for aerospace applications.

  4. Effect of heat treatments on 8090 AlLi alloy pitting susceptibility in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, A.M. [CNR, Genova (Italy). Istituto per la Corrosion Marina dei Metalli; Traverso, P. [CNR, Genova (Italy). Istituto per la Corrosion Marina dei Metalli

    1996-05-01

    The pitting susceptibility of 8090 Al-Li alloy in sea water, after different heat treatments, was investigated. Free corrosion and electrochemical tests were carried out at 25 C, in quiescent sea water at pH=8.2 and dissolved oxygen =6.5 ppm. The microstructure was examined by metallographic microscopy and by X-Ray microdiffractometry, while the corrosion layer was characterized by chemical methods and by Infrared and X-ray photoelectron spectroscopies. The following was observed: . aging treatments lead to a non homogeneous microstructure which increases the average corrosion rate as well as pitting susceptibility; . heat treatments do not affect the average passive film composition; . in all examined states, Al-Li alloy 8090 is subject to localized corrosion which takes place preferentially at the grain boundaries. (orig.)

  5. In Situ Assessment of Lattice in an Al-Li Alloy

    Science.gov (United States)

    Beaudoin, A. J.; Obstalecki, M.; Tayon, W.; Hernquist, M.; Mudrock, R.; Kenesei, P.; Lienert, U.

    2013-01-01

    The lattice strains of individual grains are measured in an Al-Li alloy, AA 2195, using high-energy X-ray diffraction at a synchrotron source. The diffraction of individual grains in this highly textured production alloy was isolated through use of a depth-defining aperture. It is shown that hydrostatic stress, and in turn the stress triaxiality, can vary significantly from grain to grain.

  6. Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments

    Science.gov (United States)

    Danford, M. D.; Mendrek, M. J.

    1998-01-01

    Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

  7. Stone cladding engineering

    CERN Document Server

    Sousa Camposinhos, Rui de

    2014-01-01

    This volume presents new methodologies for the design of dimension stone based on the concepts of structural design while preserving the excellence of stonemasonry practice in façade engineering. Straightforward formulae are provided for computing action on cladding, with special emphasis on the effect of seismic forces, including an extensive general methodology applied to non-structural elements. Based on the Load and Resistance Factor Design Format (LRDF), minimum slab thickness formulae are presented that take into consideration stress concentrations analysis based on the Finite Element Method (FEM) for the most commonly used modern anchorage systems. Calculation examples allow designers to solve several anchorage engineering problems in a detailed and objective manner, underlining the key parameters. The design of the anchorage metal parts, either in stainless steel or aluminum, is also presented.

  8. Theoretical investigation of the precipitation of δ' in Al-Li

    Science.gov (United States)

    Khachaturyan, A. G.; Lindsey, T. F.; Morris, J. W.

    1988-02-01

    This paper contains the results of a theoretical investigation of the equilibrium between a disordered fee solution and an Ll2 phase in a model binary alloy and the transformation paths that may be followed when the disordered phase is quenched into the two-phase field. The results are specifically applied to binary Al-Li alloys, in which case the ordered phase is the metastable Al3Li (δ') phase that precipitates from the disordered solid solution (α). The thermodynamic model assumes that the atoms interact in pairs with an interaction potential that is independent of the temperature and composition, and uses the “mean field approximation” for the entropy of mixing. The assumptions confine its applicability to temperatures well below the ordering temperature of the Ll2 phase. The model is used to compute the two-phase field that separates the disordered solution and the Ll2 phase. For the specific case of Al-Li, it provides results that fit the available experimental data and offer a simple explanation for the observed deviation from stoichiometry of the δ' phase. The model predicts that the disordered solution orders congruently on quenching, but is then unstable with respect to decom-position by a spinodal mechanism that leads ultimately to a state of ordered Ll2 precipitates in a disordered matrix. The results provide plausible interpretations for the transformations observed in quenched Al-Li alloys.

  9. Compression Buckling Behavior of Large-Scale Friction Stir Welded and Riveted 2090-T83 Al-Li Alloy Skin-Stiffener Panels

    Science.gov (United States)

    Hoffman, Eric K.; Hafley, Robert A.; Wagner, John A.; Jegley, Dawn C.; Pecquet, Robert W.; Blum, Celia M.; Arbegast, William J.

    2002-01-01

    To evaluate the potential of friction stir welding (FSW) as a replacement for traditional rivet fastening for launch vehicle dry bay construction, a large-scale friction stir welded 2090-T83 aluminum-lithium (Al-Li) alloy skin-stiffener panel was designed and fabricated by Lockheed-Martin Space Systems Company - Michoud Operations (LMSS) as part of NASA Space Act Agreement (SAA) 446. The friction stir welded panel and a conventional riveted panel were tested to failure in compression at the NASA Langley Research Center (LaRC). The present paper describes the compression test results, stress analysis, and associated failure behavior of these panels. The test results provide useful data to support future optimization of FSW processes and structural design configurations for launch vehicle dry bay structures.

  10. TEC – Thin Environmental Cladding

    Directory of Open Access Journals (Sweden)

    Alan Tomasi

    2015-05-01

    Full Text Available Permasteelisa Group developed with Fiberline Composites a new curtain wall system (Thin Environmental Cladding or TEC, making use of pultruded GFRP (Glass Fiber Reinforced Polymer material instead of traditional aluminum. Main advantages using GFRP instead of aluminum are the increased thermal performance and the limited environmental impact. Selling point of the selected GFRP resin is the light transmission, which results in pultruded profiles that allow the visible light to pass through them, creating great aesthetical effects. However, GFRP components present also weaknesses, such as high acoustic transmittance (due to the reduced weight and anisotropy of the material, low stiffness if compared with aluminum (resulting in higher facade deflection and sensible fire behavior (as combustible material. This paper will describe the design of the TEC-facade, highlighting the functional role of glass within the facade concept with regards to its acoustic, structural, aesthetics and fire behavior.

  11. A Study of Friction Stir Welded 2195 Al-Li Alloy by the Scanning Reference Electrode Technique

    Science.gov (United States)

    Donford, M. D.; Ding, R. J.

    1998-01-01

    A study of the corrosion of friction stir welded 2195 Al-Li alloy has been carried out using the scanning reference electrode technique (SRET). The results are compared to those obtained from a study of heterogeneously welded samples.

  12. Cladding For Transversely-Pumped Laser Rod

    Science.gov (United States)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  13. Recent Advances in Near-Net-Shape Fabrication of Al-Li Alloy 2195 for Launch Vehicles

    Science.gov (United States)

    Wagner, John; Domack, Marcia; Hoffman, Eric

    2007-01-01

    Recent applications in launch vehicles use 2195 processed to Super Lightweight Tank specifications. Potential benefits exist by tailoring heat treatment and other processing parameters to the application. Assess the potential benefits and advocate application of Al-Li near-net-shape technologies for other launch vehicle structural components. Work with manufacturing and material producers to optimize Al-Li ingot shape and size for enhanced near-net-shape processing. Examine time dependent properties of 2195 critical for reusable applications.

  14. Report on Reactor Physics Assessment of Candidate Accident Tolerant Fuel Cladding Materials in LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan [Univ. of Tennessee, Knoxville, TN (United States); Maldonado, G. Ivan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Worrall, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-28

    This work focuses on ATF concepts being researched at Oak Ridge National Laboratory (ORNL), expanding on previous studies of using alternate cladding materials in pressurized water reactors (PWRs). The neutronic performance of two leading alternate cladding materials were assessed in boiling water reactors (BWRs): iron-chromium-aluminum (FeCrAl) cladding, and silicon carbide (SiC)-based composite cladding. This report fulfills ORNL Milestone M3FT-15OR0202332 within the fiscal year 2015 (FY15)

  15. Study of localized corrosion in aluminum alloys by the scanning reference electrode technique

    Science.gov (United States)

    Danford, M. D.

    1995-01-01

    Localized corrosion in 2219-T87 aluminum (Al) alloy, 2195 aluminum-lithium (Al-Li) alloy, and welded 2195 Al-Li alloy (4043 filler) have been investigated using the relatively new scanning reference electrode technique (SRET). Anodic sites are more frequent and of greater strength in the 2195 Al-Li alloy than in the 2219-T87 Al alloy, indicating a greater tendency toward pitting for the latter. However, the overall corrosion rates are about the same for these two alloys, as determined using the polarization resistance technique. In the welded 2195 Al-Li alloy, the weld bean is entirely cathodic, with rather strongly anodic heat affected zones (HAZ) bordering both sides, indicating a high probability of corrosion in the HAZ parallel to the weld bead.

  16. Improving fatigue property of Al-Li alloy by thermo-mechanical treatment

    Institute of Scientific and Technical Information of China (English)

    丁剑; 张荻; 范同祥; 吕维洁; 覃继宁

    2003-01-01

    Tension-compression fatigue test was performed to study the effect of the cold working + ageing treatment on the fatigue property of Al-Li alloy under stress-controlled condition. The main results show that: fatigue strength of specimen is improved obviously after cold working + ageing treatment; compared to the simple ageing treatment, the necessary ageing time can be reduced apparently to reach the peak-ageing strengthening effect; the fatigue strength of specimen cut from the vertical direction to cold working direction is higher than that cut from the parallel direction.

  17. Effects of Magnetic Field on Fracture of Al-Li Alloy Containing Cerium

    Institute of Scientific and Technical Information of China (English)

    刘兵; 王西宁; 陈铮

    2003-01-01

    The effects of magnetic field on fracture feature and microstructure of Al-Li alloys containing Ce were investigated. Experiment results show that the fracture features and the microstructures are changed with the magnetic field. The fracture surface of the alloys is mainly quasi-cleavage without applying magnetic field. With a magnetic field, the fracture of quasi-cleavage changes to more secondary cracks and less quasi-cleavage plates on fracture surface. Grains become thinner and uniform with applying magnetic field. The influence of magnetic field on atom diffusion was discussed.

  18. A surface analytical examination of Stringer particles in Al-Li-Cu alloys

    Science.gov (United States)

    Larson, L. A.; Avalos-Borja, M.; Pizzo, P. P.

    1983-01-01

    A surface analytical examination of powder metallurgy processed Al-Li-Cu alloys was conducted. The oxide stringer particles often found in these alloys was characterized. Particle characterization is important to more fully understand their impact on the stress corrosion and fracture properties of the alloy. The techniques used were SIMS (Secondary Ion Mass Spectroscopy) and SAM (Scanning Auger Microscopy). The results indicate that the oxide stringer particles contain both Al and Li with relatively high Li content and the Li compounds may be associated with the stringer particles, thereby locally depleting the adjacent matrix of Li solute.

  19. Effect of Electric Field on Conductivity and Vickers Hardness of an Al-Li Alloy

    Science.gov (United States)

    Liu, Bing; Chen, Da-Rong; Chen, Zheng; Wang, Yong-Xin; Li, Xiao-Ling

    2003-11-01

    Static electric fields were applied on an aluminium-lithium alloy during solution treatment. The conductivity and Vickers hardness of the quenched Al-Li alloy is changed with the effect of electric field. The Vickers hardness increases with the applied electric field for a certain solutionizing time but decreases with the time under an electric field. In the absence of the electric field, the Vickers hardness and the conductivity increase synchronously, while reversed after electric field treatment. Positive and negative electric fields had the similar effect. The change of the local electron density in alloy caused by electric field is presented to explain the effect.

  20. Computer Simulation of Ordering and Atom Clustering in Aging Binary Al-Li Alloy

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-ling; CHEN Zheng; WANG Yong-xin; HU Ming-juan

    2004-01-01

    Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (lro.) parameter and composition deviation order parameter from single-site occupation probabilities of Li atom. The results show that when the alloy lies in metastable region in the phase diagram ordering and atom clustering occur simultaneously. As the composition of the alloy increases ordering occurs earlier than atom clustering gradually. When the alloy lies in instable region atom clustering takes place after the congruent ordering completes. It has also been found that the incubation period of the phase transformation is shortened as the composition increases.

  1. Microstructure and low-temperature plastic deformation of Al-Li alloy

    Science.gov (United States)

    Isaev, N. V.; Zabrodin, P. A.; Spuskanyuk, V. Z.; Davydenko, A. A.; Pustovalov, V. V.; Fomenko, V. S.; Braude, I. S.

    2012-01-01

    Features of the plastic deformation of solid Al-Li solutions with microstructures formed by direct and angular hydroextrusion are studied under tension at temperatures of 4.2-350 K. It is found that the grain size reductions, increases in the average density of defects, and changes in the orientational textures during combined hydroextrusion lead to increased strength and reduced plasticity of the microcrystalline alloy relative to initially large-grained samples. The high yield stress of the microcrystalline alloy is explained by a higher grain density and the evolution of an orientational texture. The strong temperature dependence of the yield stress is typical of thermally activated interactions between dislocations and local obstacles in the form of deformation defects produced during hydroextrusion. The low plasticity of the microcrystalline alloy, which already shows up as a localization of plastic deformation with small deformations, is caused by a low rate of work hardening owing to enhanced dynamic recovery of fine grains even at low temperatures. The rate of dynamic recovery decreases, while uniform deformation increases, at temperatures of 77 K and below. Based on data on the high stress rate sensitivity at temperatures above 77 K and the low activation volume for plastic deformation of microcrystalline Al-Li, it is proposed that high-angle grain boundaries may serve as highly efficient sources and sinks of mobile dislocations.

  2. Mechanistic Study of Delamination Fracture in Al-Li Alloy C458 (2099)

    Science.gov (United States)

    Tayon, W. A.; Crooks, R. E.; Domack, M. S.; Wagner, J. A.; Beaudoin, A. J.; McDonald, R. J.

    2009-01-01

    Delamination fracture has limited the use of lightweight Al-Li alloys. In the present study, electron backscattered diffraction (EBSD) methods were used to characterize crack paths in Al-Li alloy C458 (2099). Secondary delamination cracks in fracture toughness samples showed a pronounced tendency for fracture between grain variants of the same deformation texture component. These results were analyzed by EBSD mapping methods and simulated with finite element analyses. Simulation procedures include a description of material anisotropy, local grain orientations, and fracture utilizing crystal plasticity and cohesive zone elements. Taylor factors computed for each grain orientation subjected to normal and shear stresses indicated that grain pairs with the largest Taylor factor differences were adjacent to boundaries that failed by delamination. Examination of matching delamination fracture surface pairs revealed pronounced slip bands in only one of the grains bordering the delamination. These results, along with EBSD studies, plasticity simulations, and Auger electron spectroscopy observations support a hypothesis that delamination fracture occurs due to poor slip accommodation along boundaries between grains with greatly differing plastic response.

  3. The stress-corrosion behavior of Al-Li-Cu alloys: A comparison of test methods

    Science.gov (United States)

    Rizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1982-01-01

    Two powder metallurgy processed (Al-Li-Cu) alloys with and without Mg addition were studied in aqueous 3.5% NaCl solution during the alternate immersion testing of tuning fork specimens, slow crack growth tests using fracture mechanics specimens, and the slow strain rate testing of straining electrode specimens. Scanning electron microscopy and optical metallography were used to demonstrate the character of the interaction between the Al-Li-Cu alloys and the selected environment. Both alloys are susceptible to SC in an aqueous 3.5% NaCl solution under the right electrochemical and microstructural conditions. Each test method yields important information on the character of the SC behavior. Under all conditions investigated, second phase particles strung out in rows along the extrusion direction in the alloys were rapidly attacked, and played principal role in the SC process. With time, larger pits developed from these rows of smaller pits and under certain electrochemical conditions surface cracks initiated from the larger pits and contributed directly to the fracture process. Evidence to support slow crack growth was observed in both the slow strain rate tests and the sustained immersion tests of precracked fracture mechanics specimens. The possible role of H2 in the stress corrosion cracking process is suggested.

  4. Intrinsic fatigue crack growth rates for Al-Li-Cu-Mg alloys in vacuum

    Science.gov (United States)

    Slavik, D. C.; Blankenship, C. P., Jr.; Starke, E. A., Jr.; Gangloff, R. P.

    1993-01-01

    The influences of microstructure and deformation mode on inert environment intrinsic fatigue crack propagation were investigated for Al-Li-Cu-Mg alloys AA2090, AA8090, and X2095 compared to AA2024. The amount of coherent shearable delta-prime (Al3Li) precipitates and extent of localized planar slip deformation were reduced by composition (increased Cu/Li in X2095) and heat treatment (double aging of AA8090). Intrinsic growth rates, obtained at high constant K(max) to minimize crack closure and in vacuum to eliminate any environmental effect, were alloy dependent; da/dN varied up to tenfold based on applied Delta-K or Delta-K/E. When compared based on a crack tip cyclic strain or opening displacement parameter, growth rates were equivalent for all alloys except X2095-T8, which exhibited unique fatigue crack growth resistance. Tortuous fatigue crack profiles and large fracture surface facets were observed for each Al-Li alloy independent of the precipitates present, particularly delta-prime, and the localized slip deformation structure. Reduced fatigue crack propagation rates for X2095 in vacuum are not explained by either residual crack closure or slip reversibility arguments; the origin of apparent slip band facets in a homogeneous slip alloy is unclear.

  5. The effects of zinc addition on the environmental stability of Al-Li alloys

    Science.gov (United States)

    Kilmer, Raymond J.; Stoner, Glenn E.

    1990-01-01

    It was found that relatively small addition of Zn can improve the stress corrosion cracking (SCC) resistance of Al-Li alloys. However, the mechanism by which this is accomplished is unclear. The role that Zn plays in altering the behavior of Alloy 8090 is investigated. Early results suggest that Zn additions increase the volume fraction of delta(Al3Li) precipitation and differential scanning calorimetry (DSC) on these alloys confirms this. The four alloys studied each had initial compositions lying in the 8090 window and had varying amounts of Zn added to them. Alloy 8090, like other Al-Li alloys, displays a delta' precipitate free zone (PFZ) upon artificial aging along the grain and subgrain boundaries. However Zn additions greatly decreased or eliminated a delta' PFZ after 100 hours at 160 C. This implies that the subgrain boundary precipitation kinetics are being altered and suppressed. Furthermore, there appears to be a window of Zn concentration above which a delta ' PFZ can reappear with the nucleation and growth of a currently unidentified precipitate on the boundaries. Polarization experiments were performed and the results presented. The experiments were performed in deaerated 3.5 w/o NaCl in both as received (T3) condition and at peak aging of 100 hours at 160 C. The aging profile was determined via Vickers Hardness tests.

  6. On the intergranular fracture behavior of high-temperature plastic deformation of 1420 Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The tensile deformation hot simulation test of as-cast 1420 Al-Li alloy was performed on Gleeble-1500 Thermal Simulator in the deformation temperature range from 350 to 450 ℃, and the strain rate range from 0.01 to 10.0 s-1.The tensile fracture behavior of the 1420 Al-Li alloy at high temperature was studied experimently. The results show that the tensile fracture mode of the 1420 Al-Li alloy at high temperature is changed from typical transgranular ductile fracture to intergranular brittle fracture with the increase of the deformation temperature and the strain rate. It is made out that the precipitation of LiH is the fundamental reason for the intergranular brittle fracture of the 1420 Al-Li alloy at high temperature. The mechanism of hydrogen embrittlement of the 1420 Al-Li alloy at high temperature was discussed, and it was proposed that the hydrogen embrittlement at high temperature is an integrated function of the dynamic and the static force, which enrichs the theories of hydrogen embrittlement.

  7. A positron study on the microstructural evolution of Al-Li based alloys in the early stages of plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Diego, N. de; Rio, J. del [Univ. Complutense, Madrid (Spain). Dept. de Fisica de Materiales; Romero, R.; Somoza, A. [Univ. Nacional del Centro de la Provincia de Buenos Aires, Tandil (Argentina). Inst. de Fisica de Materiales]|[Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (Argentina)

    1997-11-01

    The formation of voids by coalescence of microvoids initiated at precipitates has been proposed to explain the fracture mechanisms in alloys containing a large number of second phase particles whereas in binary Al-Li alloys with shearable particles the brittleness could be linked with the grain boundary fracture. Most of the microstructure studies of Al-Li alloys have been performed by deforming to fracture; however, little is known about the processes and mechanisms involved in the early stages of plastic deformation. Butler et al. have studied a quaternary Al-Li alloy and have found that there is a critical effective strain to cause voiding, which is about 0.06 and 0.1% for the aged and for the solution treated material respectively. It is very well established that positrons are very sensitive to vacancy-like defects. With the aim of clarifying the behavior of Al-Li based alloys in the very early stages of deformation, and detecting the eventual formation of microvoids, the authors have studied the response of the positron lifetime parameters to the degrees of deformation in age-hardenable Al-Li based alloys plastically deformed under tensile stress.

  8. Effect of current pulses on fracture morphology in superplastic deformation of 2091 Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The effect of current pulses on the fracture morphology in the superplastic deformation of 2091 AlLi alloy at two kinds of initial strain rate ((ε)1 = 3.33 × 10 -3 s-1;(ε)2= 3.33 × 10-2 s- 1 ) was investigated. Experimental results show that current pulse turns fracture of superplastic deformation at low strain rate from local interior fracture morphology to typical fracture by growth and interlinkage of cavities, and at high strain rate from rough grain boundary surface to smooth grain boundary surface. It is indicated that the characteristic, that current pulse promotes atomic diffusion, maintains an equiaxial grain microstructure at low strain rate, and accelerates the development of diffusional type of cavity and relaxes stress concentration at triple junction of grain boundaries at high strain rate, and makes the superplastic deformation at two kinds of strain rate show a normal superplastic fracture morphology.

  9. Structure and Mechanical Properties of Al-Li Alloys as Cast

    Directory of Open Access Journals (Sweden)

    J. Augustyn-Pieniążek

    2013-04-01

    Full Text Available The high mechanical properties of the Al-Li-X alloys contribute to their increasingly broad application in aeronautics, as an alternative for the aluminium alloys, which have been used so far. The aluminium-lithium alloys have a lower specific gravity, a higher nucleation and crack spread resistance, a higher Young’s module and they characterize in a high crack resistance at lower temperatures. The aim of the research planned in this work was to design an aluminium alloy with a content of lithium and other alloy elements. The research included the creation of a laboratorial melt, the microstructure analysis with the use of light microscopy, the application of X-ray methods to identify the phases existing in the alloy, and the microhardness test.

  10. Characterization of the precipitates in Al-Li(8090) alloy using thermal measurements and TEM examinations

    Science.gov (United States)

    Gaber, A.; Afify, N.

    2002-04-01

    Variation of thermophysical properties of Al-Li (8090) quenched from the solid solution state (803 K) during heating (10 K/min) has been used to determine the temperatures at which the phase transformations take place. Transmission electron microscopic examinations were used to characterize the developed precipitates. It has been shown that the thermal properties can be used as a powerful tool for detecting phase transformations. Microstructural examinations after aging at 373, 438, 563 and 673 K revealed the formation of GP zones, δ‧-(Al 3Li), T B-(Al 7Cu 4Li) and T 2-(Al 6CuLi 3) precipitates, respectively. δ‧-particles and T B-(Al 7Cu 4Li) were observed to be nucleated intragranularly, whereas T 2-particles were observed to grow on the grain boundaries.

  11. Influence of grain orientations on the initiation of fatigue damage in an Al-Li alloy.

    Science.gov (United States)

    Taylor; Zhai; Wilkinson; Martin

    1999-09-01

    The variation in microstructure and texture in a rectangular bar extruded from a billet of spray-cast 8090 Al-Li alloy has been examined. The fine grain size of the as sprayed billet and the moderate extrusion ratio ( approximately 25 : 1) were seen to cause geometric dynamic recrystallization (GDR) in regions of higher strain towards the edge of the bar. The grain morphology varied from the expected elongated grains at the centre of the bar to equiaxed grains where GDR occurred at the bar edges. A + double fibre texture, significantly distorted towards rolling components and varying through the bar thickness, was found using electron backscatter diffraction. Fatigue resulted in a high density of short secondary cracks, many of which had arrested at grain boundaries. The cracks preferentially nucleated in grains from the fibre texture corresponding to high Schmid factors.

  12. Effect of two-stage aging on superplasticity of Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    LUO Zhi-hui; ZHANG Xin-ming; DU Yu-xuan; YE Ling-ying

    2006-01-01

    The effect of two-stage aging on the microstructures and superplasticity of 01420 Al-Li alloy was investigated by means of OM, TEM analysis and stretching experiment. The results demonstrate that the second phase particles distributed more uniformly with a larger volume fraction can be observed after the two-stage aging (120 ℃, 12 h+300 ℃, 36 h) compared with the single-aging(300 ℃, 48 h). After rolling and recrystallization annealing, fine grains with size of 8-10 μm are obtained, and the superplastic elongation of the specimens reaches 560% at strain rate of 8×10-4 s-1 and 480 ℃. Uniformly distributed fine particles precipitate both on grain boundaries and in grains at lower temperature. When the sheet is aged at high temperature, the particles become coarser with a large volume fraction.

  13. Strength and microstructure of 2091 Al-Li alloy TIG welded joint

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The microstructure and tensile properties of TIG welding joints of 2091 Al-Li alloy were investigated both in as-welded and different postweld heat treatment condition. The results show that solution strengthening played an important role in the as-welded condition, though the precipitation strengthening δ' phase formed already in the as-welded weld metal, but its effect was not apparent due to the lower volume fraction of δ' phase. So the strength coefficient (φ) of the welded joint/base metal was 64%. After artificially aging heat treatment, the precipitation strengthening effect increased much due to the formation of more δ' phase and s' phase. Its φ value was increased up to 89%. The highest strength of the welded joints was obtained after solid solution and then artificially aged heat treatment. Due to the proper size of precipitation strengthening phases and their well distribution, the φ value was increased up to 98%.

  14. Investigation of exfoliation corrosion of rolled AA8090 Al-Li alloy using electrochemical impedance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    李劲风; 张昭; 曹发和; 程英亮; 张鉴清; 曹楚南

    2003-01-01

    The exfoliation morphologies and electrochemical impedance spectroscopy (EIS) features of as-received rolled AA8090 Al-Li alloy in EXCO solution were studied. The EIS was simulated using an equivalent circuit. The results show that once the exfoliation occurs, the EIS is composed of two capacitive arcs at high frequency and mediate-low frequency; among them, the capacitance corresponding to high frequency (C1) is originated from original flat alloy surface, while the capacitance corresponding to mediate-low frequency (C2) from new interface exposed to EXCO solution due to the exfoliation and the ratio of C2 to C1 increases with exfoliation degree. It is advanced that the exfoliation degree can be quantitatively judged through this ratio.

  15. Evaluation of Engineering Properties of AL-Li Alloy X2096-T8A3 Extrusion Products

    Science.gov (United States)

    Flom, Y.; Viens, M.; Wang, L.

    1999-01-01

    Mechanical, thermal fatigue and stress corrosion properties were determined for the two lots of Al-Li X2096-T8A3 extruded beams. Based on the test results, the beams were accepted as the construction material for fabrication of the Hubble Space Telescope new Solar Array Support Structure.

  16. Al-Li alloy AA2198's very high cycle fatigue crack initiation mechanism and its fatigue thermal effect

    Science.gov (United States)

    Xu, Luopeng; Cao, Xiaojian; Chen, Yu; Wang, Qingyuan

    2015-10-01

    AA2198 alloy is one of the third generation Al-Li alloys which have low density, high elastic modulus, high specific strength and specific stiffness. Compared With the previous two generation Al-Li alloys, the third generation alloys have much improved in alloys strength, corrosion resistance and weldable characteristic. For these advantages, the third generation Al-Li alloys are used as aircraft structures, such as C919 aviation airplane manufactured by China and Russia next generation aviation airplane--MS-21. As we know, the aircraft structures are usually subjected to more than 108 cycles fatigue life during 20-30 years of service, however, there is few reported paper about the third generation Al-Li alloys' very high cycle fatigue(VHCF) which is more than 108 cycles fatigue. The VHCF experiment of AA2198 have been carried out. The two different initiation mechanisms of fatigue fracture have been found in VHCF. The cracks can initiate from the interior of the testing material with lower stress amplitude and more than 108 cycles fatigue life, or from the surface or subsurface of material which is the dominant reason of fatigue failures. During the experiment, the infrared technology is used to monitor the VHCF thermal effect. With the increase of the stress, the temperature of sample is also rising up, increasing about 15 °C for every 10Mpa. The theoretical thermal analysis is also carried out.

  17. TEC – Thin Environmental Cladding

    Directory of Open Access Journals (Sweden)

    Alan Tomasi

    2014-06-01

    Full Text Available Corresponding author: Alan Tomasi, Group R&D Project Manager, Permasteelisa S.p.A., viale E. Mattei 21/23 | 31029 Vittorio Veneto, Treviso, Italy. Tel.: +39 0438 505207; E-mail: a.tomasi@permasteelisagroup.com; www.permasteelisagroup.com Permasteelisa Group developed with Fiberline Composites a new curtain wall system (Thin Environmental Cladding or TEC, making use of pultruded GFRP (Glass Fiber Reinforced Polymer material instead of traditional aluminum. Main advantages using GFRP instead of aluminum are the increased thermal performance and the limited environmental impact. Selling point of the selected GFRP resin is the light transmission, which results in pultruded profiles that allow the visible light to pass through them, creating great aesthetical effects. However, GFRP components present also weaknesses, such as high acoustic transmittance (due to the reduced weight and anisotropy of the material, low stiffness if compared with aluminum (resulting in higher facade deflection and sensible fire behavior (as combustible material. This paper will describe the design of the TEC-facade, highlighting the functional role of glass within the facade concept with regards to its acoustic, structural, aesthetics and fire behavior.

  18. Corrosion Behavior of Copper-Clad Steel Bars with Unclad Two-End Faces for Grounding Grids in the Red Clay Soil

    Science.gov (United States)

    Shao, Yupei; Mu, Miaomiao; Zhang, Bing; Nie, Kaibin; Liao, Qiangqiang

    2017-02-01

    Iron-aluminum oxides in the red soil have a significant impact on the corrosion behavior of the metal for grounding grids. Effects of iron-aluminum oxides on the corrosion behavior of the cross section of copper-clad steel in the red soil have been investigated using electrochemical impedance spectroscopy and Tafel polarization. All the data indicate that the iron-aluminum oxides can promote the corrosion of copper-clad steel in the red soil. The corrosivity of the red soil greatly increases after iron-aluminum oxides are added into the soil. Iron-aluminum oxides promote galvanic corrosion of copper-clad steel and increase the corrosion degree of the center steel layer. The iron-aluminum oxides stimulate corrosion process of copper-clad steel acting as a cathodic depolarizing agent. XRD results further validate that the corrosion products of the copper-clad steel bar mainly consist of Fe3O4 and Cu2O.

  19. Exfoliation corrosion susceptibility of 8090 Al-Li alloy examined by electrochemical impedance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    蔡超; 李劲风; 郑子樵; 张昭

    2004-01-01

    The exfoliation corrosion susceptibility and electrochemical impedance spectroscopy(EIS) of rolled and peak-aged 8090 Al-Li alloys in EXCO solution were studied, and the EIS after exfoliation was simulated. Once exfoliation occurs, two capacitive arcs appear in the EIS at high-mediate frequency and mediate-low frequency respective ly. The exfoliation-attacked alloy surface consists of two parts, an original flat alloy surface and a new inter-face exposed to EXCO solution due to the exfoliation. The capacitance corresponding to the new exfoliation inter-face in creases approximately linearly with time at early exfoliation stage, due to the enlargement of the new inter-face. Then it maintains stable, due to the corrosion product covering on the new inter-face. The exfoliation susceptibility can be judged through the average slope of the capacitance vs time curve of the early exfoliation stage. This average slope of the rolled 8090 alloy is much higher than that of the peak-aged 8090 alloy, accordingly the rolled 8090 alloy is more susceptible to exfoliation than the peak-aged 8090 alloy.

  20. Structure-Property Correlations in Al-Li Alloy Integrally Stiffened Extrusions

    Science.gov (United States)

    Hales, Stephen J.; Hafley, Robert A.

    2001-01-01

    The objective of this investigation was to establish the relationship between mechanical property anisotropy, microstructure and crystallographic texture in integrally 'T'-stiffened extruded panels fabricated from the Al-Li alloys 2195, 2098 and 2096. In-plane properties were measured as a function of orientation at two locations in the panels, namely mid-way between (Skin), and directly beneath (Base), the integral 'T' stiffeners. The 2195 extrusion exhibited the best combination of strength and toughness, but was the most anisotropic. The 2098 extrusion exhibited lower strength and comparable toughness, but was more isotropic than 2195. The 2096 extrusion exhibited the lowest strength and poor toughness, but was the most isotropic. All three alloys exhibited highly elongated grain structures and similar location-dependent variations in grain morphology. The textural characteristics comprised a beta + fiber texture, similar to rolled product, in the Skin regions and alpha + fiber texture, comparable to axisymmetric extruded product, in the Base regions. In an attempt to quantitatively correlate texture with yield strength anisotropy, the original 'full constraint' Taylor model and a variant of the 'relaxed constraint' model, explored by Wert et al., were applied to the data. A comparison of the results revealed that the Wert model was consistently more accurate than the Taylor model.

  1. Hot Deformation Behavior and Processing Maps of 2099 Al-Li Alloy

    Science.gov (United States)

    Chen, Bin; Tian, Xiao-lin; Li, Xiao-ling; Lu, Chen

    2014-06-01

    Hot deformation behavior and processing maps of the 2099 Al-Li alloy are investigated by tensile test at the temperature range from 250 to 450 °C and the strain rate range from 0.001 to 5.0 s-1. The typical true stress-true strain curves show that the flow stress increases with increasing the strain rate and decreasing the deforming temperature. All curves exhibit rapid work hardening at an initial stage of strain followed by remarkable dynamic softening. Based on the flow stress behavior, the processing maps are calculated and analyzed according to the dynamic materials model (DMM). The processing maps exhibit an instability domain in the temperature and strain rate ranges: T = 250-260 °C and = 0.1-0.5 s-1. The maps also exhibit an optimum hot working condition in the stability domain that occurs in the temperature of 400 °C for a strain rate of 0.001 s-1 and having a maximum efficiency of 60%. The microstructural examinations exhibit the occurrence of dynamic recovery (DRV) during hot deformation of the 2099 alloy which is the dominant softening mechanism in the alloy. The fracture behavior changes from a brittle fracture to a ductile fracture as strain rate decreases and temperature increases.

  2. Stress Concentration and Fracture at Inter-variant Boundaries in an Al-Li Alloy

    Science.gov (United States)

    Crooks, Roy; Tayon, Wes; Domack, Marcia; Wagner, John; Beaudoin, Armand

    2009-01-01

    Delamination fracture has limited the use of lightweight Al-Li alloys. Studies of secondary, delamination cracks in alloy 2090, L-T fracture toughness samples showed grain boundary failure between variants of the brass texture component. Although the adjacent texture variants, designated B(sub s1) and B(sub s2), behave similarly during rolling, their plastic responses to mechanical tests can be quite different. EBSD data from through-thickness scans were used to generate Taylor factor maps. When a combined boundary normal and shear tensor was used in the calculation, the delaminating grains showed the greatest Taylor Factor differences of any grain pairs. Kernel Average Misorientation (KAM) maps also showed damage accumulation on one side of the interface. Both of these are consistent with poor slip accommodation from a crystallographically softer grain to a harder one. Transmission electron microscopy was used to confirm the EBSD observations and to show the role of slip bands in the development of large, interfacial stress concentrations. A viewgraph presentation accompanies the provided abstract.

  3. Effect of cold compression on precipitation and conductivity of an Al-Li-Cu alloy.

    Science.gov (United States)

    Khan, A K; Robinson, J S

    2008-12-01

    Transmission electron microscopy has been used to investigate the effect of increasing the degree of deformation applied by cold compression on the ageing kinetics and electrical conductivity response of an Al-Li-Cu alloy containing Mg and Ag. When cold compressed greater than 3%, the increased dislocation density accelerates the widespread precipitation of the T(1) phase resulting in an enhanced age hardening response. The lengthening rate of T(1) precipitates is also reduced in this cold compressed condition owing to the reduced local solute supersaturation, a result of the widespread precipitation of T(1) plates. Cold compression by less than 3% does not increase the age hardening response, and the precipitation of GP zones/theta'' appears to be suppressed. Precipitation of the T(1) phase is also not significantly enhanced compared with that of the more than 3% cold compressed conditions. The anomalous decrease in electrical conductivity is associated with the nucleation and growth of the T(1) phase. Strain fields around T(1) precipitates combined with the increased volume fraction of T(1) are thought to be the cause of the anomalous conductivity behaviour.

  4. Artifacts introduced by ion milling in Al-Li-Cu alloys.

    Science.gov (United States)

    Singh, A K; Imam, M A; Sadananda, K

    1988-04-01

    Ion milling is commonly used to prepare specimens for observation under transmission electron microscope (TEM). This technique sometimes introduces artifacts in specimens contributing to misleading interpretation of TEM results as observed in the present investigation of Al-Li-Cu alloys. This type of alloy, in general, contains several kinds of precipitates, namely delta', T1, and theta'. It is found that ion milling even for a short time produces drastic changes in the precipitate characteristics as compared to standard electropolishing methods of specimen preparation for TEM. Careful analysis of selected area diffraction patterns and micrographs shows that after ion milling delta' precipitates are very irregular, whereas other precipitates coarsen and they are surrounded by misfit dislocations. In situ hot-stage TEM experiments were performed to relate the microstructure to that observed in the ion-milled specimen. Results and causes of ion milling effects on the microstructure are discussed in relation to standard electropolishing techniques and in situ hot-stage experiment.

  5. Evolution of grain structure in AA2195 Al-Li alloy plate during recrystallization

    Institute of Scientific and Technical Information of China (English)

    DU Yu-xuan; ZHANG Xin-ming; YE Ling-ying; LIU Sheng-dan

    2006-01-01

    The evolution of the grain structures in AA2195 Al-Li alloy plate warm-rolled by 80% reduction during recrystallization annealing at 500 ℃ was investigated by electron backscatter diffraction, scanning electron microscopy and transmission electron microscopy. It is found that the elongated grain structures are caused by the lamellar distribution of recrystallization nucleation sites,being lack of large second phase particles (> 1 μm), and dispersive coherent particles (such as δ'andβ) concentrated in planar bands.The recrystallization process may be separated into three stages: firstly, recrystallization nucleation occurs heterogeneously, and the nuclei are concentrated in some planar zones parallel to rolling plane. Secondly, the grain boundaries interacted with small particles concentrate in planar bands, which is able to result in the elongated grain structures. The rate of the grain growth is controlled by the dissolution of these small particles. Thirdly, after most of small particles are dissolved, their hindrance to migration of the grain boundaries fades away, and the unrecrystallized zones are consumed by adjacent recrystallized grains. The migration of high angle grain boundaries along normal direction leads a gradual transformation from the elongated grains to the nearly equiaxed, which is driven by the tension of the grain boundaries.

  6. Electrochemical Behavior of Aluminum in Nitric Acid

    Institute of Scientific and Technical Information of China (English)

    CHEN; Hui; ZHU; Li-yang; LIN; Ru-shan; TAN; Hong-bin; HE; Hui

    2013-01-01

    Aluminum is one of cladding materials for nuclear fuel,it is important to investigate the electrolytic dissolution of aluminum in nitric acid.The electrochemical impedance spectroscopy,polarization curve and cyclic voltammetry cure of anodic aluminum electrode in nitric acid under various conditions were collected(Fig.1).It turns out,under steady state,the thickness of the passivated film of aluminum

  7. Influence of Electric Field on Mechanical Properties of Al-Li Alloy Containing Cerium and Electronic Mechanism

    Institute of Scientific and Technical Information of China (English)

    刘兵; 陈铮; 王永欣; 王西宁

    2001-01-01

    The effect of electric field on the mechanical properties and microstructure of Al-Li alloy containing Ce was investigated, and mechanism was discussed. The experimental results show that the ductility of the alloy is enhanced by the electric field. The fracture features are changed and the precipitates are dispersed under the effect of the electric field. The mechanism discussion reveals that the effects of the electric field on the alloy are due to the change of the electron density in the alloy.

  8. Process Optimization of Dual-Laser Beam Welding of Advanced Al-Li Alloys Through Hot Cracking Susceptibility Modeling

    Science.gov (United States)

    Tian, Yingtao; Robson, Joseph D.; Riekehr, Stefan; Kashaev, Nikolai; Wang, Li; Lowe, Tristan; Karanika, Alexandra

    2016-07-01

    Laser welding of advanced Al-Li alloys has been developed to meet the increasing demand for light-weight and high-strength aerospace structures. However, welding of high-strength Al-Li alloys can be problematic due to the tendency for hot cracking. Finding suitable welding parameters and filler material for this combination currently requires extensive and costly trial and error experimentation. The present work describes a novel coupled model to predict hot crack susceptibility (HCS) in Al-Li welds. Such a model can be used to shortcut the weld development process. The coupled model combines finite element process simulation with a two-level HCS model. The finite element process model predicts thermal field data for the subsequent HCS hot cracking prediction. The model can be used to predict the influences of filler wire composition and welding parameters on HCS. The modeling results have been validated by comparing predictions with results from fully instrumented laser welds performed under a range of process parameters and analyzed using high-resolution X-ray tomography to identify weld defects. It is shown that the model is capable of accurately predicting the thermal field around the weld and the trend of HCS as a function of process parameters.

  9. Strength distribution of fatigue crack initiation sites in an Al-Li alloy

    Science.gov (United States)

    Zhai, T.

    2006-10-01

    The stress-number of cycles to failure (S-N) curves were measured along the short-transverse (S) and rolling (L) directions of a hot-cross-rolled AA 8090 Al-Li alloy plate (45-mm thick). The alloy was solution heat treated, quenched in water, strained by 6 pct, and peak aged. Fatigue tests were carried out in four-point bend at room temperature, 20 Hz, R=0.1, in air. It was found that the fatigue limits in the S and L directions were 147 and 197 MPa, respectively. The crack population on the surface of a sample at failure increased with the applied stress level and was found to be a Weibull function of the applied maximum stress in this alloy. The strength distribution of fatigue weakest links, where cracks were initiated, was derived from the Weibull function determined by the experimental data. The fatigue weakest-link density was defined as the crack population per unit area at a stress level close to the ultimate tensile stress and can be regarded as a materials property. The density and strength distribution of fatigue weakest links were found to be markedly different between the L and S directions, accounting for the difference in fatigue limit between the directions in this alloy. They were also found to be different between S-L and S-T samples, and between L-T and L-S samples of this alloy, which could not be revealed by the corresponding S-N curves measured. These differences were due to the anisotropy of the microstructures in different directions in this alloy.

  10. B218 Weld Filler Wire Characterization for Al-Li Alloy 2195

    Science.gov (United States)

    Bjorkman, Gerry; Russell, Carolyn

    2000-01-01

    NASA Marshall Space Flight Center, Lockheed Martin Space Systems- Michoud Operations, and McCook Metals have developed an aluminum-copper weld filler wire for fusion welding aluminum lithium alloy 2195. The aluminum-copper based weld filler wire has been identified as B218, a McCook Metals designation. B218 is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties over the 4043 aluminum-silicon weld filler wire, which is currently used to weld 2195 on the Super Lightweight External Tank for the NASA Space Shuttle Program. An initial characterization was performed consisting of a repair weld evaluation using B218 and 4043 weld filler wires. The testing involved room temperature and cryogenic repair weld tensile testing along with fracture toughness testing. From the testing, B218 weld filler wire produce enhanced repair weld tensile strength, ductility, and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding aluminum lithium alloy 2195 over 4043.

  11. Strategy and method for nanoporous cladding formation on silica optical fiber.

    Science.gov (United States)

    Chen, Hui; Tian, Fei; Liu, Kai; Kanka, Jiri; Du, Henry

    2016-06-15

    We demonstrate the proof of an innovative concept of fabricating nanostructured aluminum oxide cladding on silica optical fiber. Our fabrication strategy entails freeze-coating aluminum on silica fiber and its subsequent anodization, resulting in the formation of anodized aluminum oxide (AAO) cladding with highly organized nanopore channels vertically aligned to the fiber axis. We show that the structure (diameter of pore channels and the porosity) of AAO cladding can be controlled by varying anodization conditions such as the type and concentration of electrolyte solutions and applied voltage. The versatility of AAO as a cladding with tunable structural and optical characteristics and/or a host of other functional nanostructures within the pore channels has the potential to enable a new class of specialty optical fiber for new sensor architecture and applications.

  12. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy.

    Science.gov (United States)

    Terry, Brandon C; Sippel, Travis R; Pfeil, Mark A; Gunduz, I Emre; Son, Steven F

    2016-11-05

    Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (ISP). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal ISP by ∼7s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5±4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption.

  13. Robust cladding light stripper for high-power fiber lasers using soft metals.

    Science.gov (United States)

    Babazadeh, Amin; Nasirabad, Reza Rezaei; Norouzey, Ahmad; Hejaz, Kamran; Poozesh, Reza; Heidariazar, Amir; Golshan, Ali Hamedani; Roohforouz, Ali; Jafari, S Naser Tabatabaei; Lafouti, Majid

    2014-04-20

    In this paper we present a novel method to reliably strip the unwanted cladding light in high-power fiber lasers. Soft metals are utilized to fabricate a high-power cladding light stripper (CLS). The capability of indium (In), aluminum (Al), tin (Sn), and gold (Au) in extracting unwanted cladding light is examined. The experiments show that these metals have the right features for stripping the unwanted light out of the cladding. We also find that the metal-cladding contact area is of great importance because it determines the attenuation and the thermal load on the CLS. These metals are examined in different forms to optimize the contact area to have the highest possible attenuation and avoid localized heating. The results show that sheets of indium are very effective in stripping unwanted cladding light.

  14. Analysis and optimization of process parameters in Al-SiCp laser cladding

    Science.gov (United States)

    Riquelme, Ainhoa; Rodrigo, Pilar; Escalera-Rodríguez, María Dolores; Rams, Joaquín

    2016-03-01

    The laser cladding process parameters have great effect on the clad geometry and on dilution in the single and multi-pass aluminum matrix composite reinforced with SiC particles (Al/SiCp) coatings on ZE41 magnesium alloys deposited using a high-power diode laser (HPLD). The influence of the laser power (500-700 W), scan speed (3-17 mm/s) and laser beam focal position (focus, positive and negative defocus) on the shape factor, cladding-bead geometry, cladding-bead microstructure (including the presence of pores and cracks), and hardness has been evaluated. The correlation of these process parameters and their influence on the properties and ultimately, on the feasibility of the cladding process, is demonstrated. The importance of focal position is demonstrated. The different energy distribution of the laser beam cross section in focus plane or in positive and negative defocus plane affect on the cladding-bead properties.

  15. Evolution of the internal friction in SIC particle reinforced 8090 Al-Li metal matrix composite; Evolucion de la friccion interna del material compuesto de matriz Al-Li 8090 reforzado con particulas de SiC

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Urrutia, I.; Gallego, I.; No, M. L.; San Juan, J. M.

    2001-07-01

    The present study has been undertaken to investigate the mechanisms of thermal stress relief at the range of temperatures below room temperature for the metal matrix composite Al-Li 8090/SiC. For this aim the experimental technique of internal friction has been used which has been showed up very effective. Several thermal cycles from 453 K to 100 K were used in order to measures the internal friction as well as the elastic modules of the material concluding that thermal stresses are relaxed by microplastic deformation around the reinforcements. It has been also related the variation in the elastic modules with the different levels of precipitation. (Author) 18 refs.

  16. Initial Cladding Condition

    Energy Technology Data Exchange (ETDEWEB)

    E. Siegmann

    2000-08-22

    The purpose of this analysis is to describe the condition of commercial Zircaloy clad fuel as it is received at the Yucca Mountain Project (YMP) site. Most commercial nuclear fuel is encased in Zircaloy cladding. This analysis is developed to describe cladding degradation from the expected failure modes. This includes reactor operation impacts including incipient failures, potential degradation after reactor operation during spent fuel storage in pool and dry storage and impacts due to transportation. Degradation modes include cladding creep, and delayed hydride cracking during dry storage and transportation. Mechanical stresses from fuel handling and transportation vibrations are also included. This Analysis and Model Report (AMR) does not address any potential damage to assemblies that might occur at the YMP surface facilities. Ranges and uncertainties have been defined. This analysis will be the initial boundary condition for the analysis of cladding degradation inside the repository. In accordance with AP-2.13Q, ''Technical Product Development Planning'', a work plan (CRWMS M&O 2000c) was developed, issued, and utilized in the preparation of this document. There are constraints, caveats and limitations to this analysis. This cladding degradation analysis is based on commercial Pressurized Water Reactor (PWR) fuel with Zircaloy cladding but is applicable to Boiling Water Reactor (BWR) fuel. Reactor operating experience for both PWRs and BWRs is used to establish fuel reliability from reactor operation. It is limited to fuel exposed to normal operation and anticipated operational occurrences (i.e. events which are anticipated to occur within a reactor lifetime), and not to fuel that has been exposed to severe accidents. Fuel burnup projections have been limited to the current commercial reactor licensing environment with restrictions on fuel enrichment, oxide coating thickness and rod plenum pressures. The information provided in this analysis

  17. Superplastic forming of Al-Li alloys for lightweight, low-cost structures

    Science.gov (United States)

    Hales, Stephen J.; Wagner, John A.

    1991-01-01

    Superplastic forming of advanced aluminum alloys is being evaluated as an approach for fabricating low-cost, light-weight, cryogenic propellant tanks. Built-up structure concepts (with inherent reduced scrap rate) are under investigation to offset the additional raw material expenses incurred by using aluminum lithium alloys. This approach to fabrication offers the potential for significant improvements in both structural efficiency and overall manufacturing costs. Superplasticity is the ability of specially processed material to sustain very large forming strains without failure at elevated temperatures under controlled deformation conditions. It was demonstrated that superplastic forming technology can be used to fabricate complex structural components in a single operation and increase structural efficiency by as much as 60 percent compared to conventional configurations in skin-stiffened structures. Details involved in the application of this technology to commercial grade superplastic aluminum lithium material are presented. Included are identification of optimum forming parameters, development of forming procedures, and assessment of final part quality in terms of cavitation volume and thickness variation.

  18. Influence of the Local Chemical Composition on the Mechanical Properties of Laser Beam Welded Al-Li Alloys

    Science.gov (United States)

    Enz, Josephin; Riekehr, Stefan; Ventzke, Volker; Kashaev, Nikolai

    The increasing interest of the aircraft industry in reduction of structural weight of aircrafts has resulted in the development of lightweight and high-strength Al-Li alloys as well as in the introduction of laser beam welding to the manufacturing process. The objective of this study is the investigation of the influence of variations in the chemical composition on local mechanical properties, like micro-hardness and micro-tensile strength, of CO 2 laser beam welded skin-stringer joints made from AA2196 and AA2198. Additionally the influence of the welding process on weld chemistry is studied in view of the improvement of the weld quality.

  19. Cryogenic Treatment of Al-Li Alloys for Improved Weldability, Repairability, and Reduction of Residual Stresses

    Science.gov (United States)

    Malone, Tina W.; Graham, Benny F.; Gentz, Steven J. (Technical Monitor)

    2001-01-01

    Service performance has shown that cryogenic treatment of some metals provides improved strength, fatigue life, and wear resistance to the processed material. Effects such as these were initially discovered by NASA engineers while evaluating spacecraft that had returned from the cold vacuum of space. Factors such as high cost, poor repairability, and poor machinability are currently prohibitive for wide range use of some aerospace aluminum alloys. Application of a cryogenic treatment process to these alloys is expected provide improvements in weldability and weld properties coupled with a reduction in repairs resulting in a significant reduction in the cost to manufacture and life cycle cost of aerospace hardware. The primary purpose of this effort was to evaluate the effects of deep cryogenic treatment of some aluminum alloy plate products, welds, and weld repairs, and optimize a process for the treatment of these materials. The optimized process is being evaluated for improvements in properties of plate and welds, improvements in weldability and repairability of treated materials, and as an alternative technique for the reduction of residual stresses in repaired welds. This paper will present the results of testing and evaluation conducted in this effort. These results will include assessments of changes in strength, toughness, stress corrosion susceptability, weldability, repairability, and reduction in residual stresses of repaired welds.

  20. Interactions between drops of molten Al-Li alloys and liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Hyder, M.L. [Westinghouse Savannah River Co., Aiken, SC (United States); Nelson, L.S. [Sandia National Labs., Albuquerque, NM (United States); Duda, P.M.; Hyndman, D.A. [Ktech Corp., Albuquerque, NM (United States)

    1993-08-01

    Sandia National Laboratories, at the request of the Savannah River Technology Center (SRTC), studied the interactions between single drops of molten aluminum-lithium alloys and water. Most experiments were performed with ``B`` alloy (3.1 w/o Li, balance A1). Objectives were to develop experimental procedures for preparing and delivering the melt drops and diagnostics for characterizing the interactions, measure hydrogen generated by the reaction between melt and water, examine debris recovered after the interaction, determine changes in the aqueous phase produced by the melt-water chemical reactions, and determine whether steam explosions occur spontaneously under the conditions studied. Although many H{sub 2} bubbles were generated after the drops entered the water, spontaneous steam explosions never occurred when globules of the ``B`` alloy at temperatures between 700 and 1000C fell freely through water at room temperature, or upon or during subsequent contact with submerged aluminum or stainless steel surfaces. Total amounts of H{sub 2} (STP) increased from about 2 to 9 cm{sup 3}/per gram of melt as initial melt temperature increased over this range of temperatures.

  1. The solubility of hydrogen in liquid binary Al-Li alloys

    Science.gov (United States)

    Anyalebechi, P. N.; Talbot, D. E. J.; Granger, D. A.

    1988-04-01

    The solubility of hydrogen in liquid binary aluminum alloys with 1, 2, and 3 wt pct lithium has been determined for the temperature range of 913 to 1073 K and pressure 5.3 × 104 to 10.7 × 104 Pa, using an appropriate version of Sieverts’ method. The results fit the Van’t Hoff isobar and Sieverts’ isotherm and the solubility, S, is given by: Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2113/T/k + 2.568 Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2797/T/k + 3.329 Al-1 pct Li: log( S/S°) - 1/2 log( P/P°) = -2889/T/k + 3.508 where S° is a standard value of solubility equal to 1 cm3 of diatomic hydrogen measured at 273 K and 101,325 Pa per 100 g of metal, and P° is a standard pressure equal to 101,325 Pa. Added lithium progressively increases the solubility of hydrogen in liquid aluminum, due more to its effect on the entropy of solution of hydrogen, through its influence on the liquid metal structure than to an increase in the solute hydrogen atom binding enthalpy.

  2. Electrochemical behaviour and codeposition of Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts

    Institute of Scientific and Technical Information of China (English)

    SUN Yi; ZHANG Milin; HAN Wei; YAN Yongde; YANG Yusheng; SUN Yunxia

    2013-01-01

    The electrochemical behaviour of Al,Li,and Er were investigated by electrochemical techniques,such as cyclic voltammograms,chronopotentiometric,chronoamperograms,and open circuit chronopotentiogram on molybdenum electrodes.The results showed that the underpotential deposition of erbium on pre-deposited A1 electrodes formed two A1-Er intermetallic compounds.The codeposition of Al,Li,Er occurred and formed Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts at 773 K.Different phases such as Al2Er,Al2Er3 and βLi phase of Al-Li-Er alloys were prepared by galvanostatic electrolysis and characterized by X-ray diffraction (XRD).Scanning electron microscopy (SEM) indicated that Er element mainly distributed at the grain boundary.ICP analyses showed that lithium and erbium contents of Al-Li-Er alloys could be controlled by AlCl3 and Er2O3 concentration and electrochemical parameters.

  3. Corrosion behavior of 2195 and 1420 Al-Li alloys in neutral 3.5% NaCl solution under tensile stress

    Institute of Scientific and Technical Information of China (English)

    LI Jin-feng; CHEN Wen-jing; ZHAO Xu-shan; REN Wen-da; ZHENG Zi-qiao

    2006-01-01

    The corrosion behaviors of 1420 and 2195 Al-Li alloys under 308 and 490 MPa tensile stress respectively in neutral 3.5% NaCl solution were investigated using electrochemical impedance spectroscopy(EIS) and scanning electron microscope(SEM). It is found that the unstressed 1420 alloy is featured with large and discrete pits, while general corrosion and localized corrosion including intergranular corrosion and pitting corrosion occur on the unstressed 2195 alloy. As stress is applied to 1420 alloy, the pit becomes denser and its size is decreased. While, for the stressed 2195 alloy, intergranular corrosion is greatly aggravated and severe general corrosion is developed from connected pits. The EIS analysis shows that more severe general corrosion and localized corrosion occur on the stressed 2195 Al-Li alloy than on 1420 Al-Li alloy. It is suggested that tensile stress has greater effect on the corrosion of 2195 Al-Li alloy than on 1420 Al-Li alloy.

  4. EPRI fuel cladding integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-01-01

    The objectives of the EPRI fuel program is to supplement the fuel vendor research to assure that utility economic and operational interests are met. To accomplish such objectives, EPRI has conducted research and development efforts to (1) reduce fuel failure rates and mitigate the impact of fuel failures on plant operation, (2) provide technology to extend burnup and reduce fuel cycle cost. The scope of R&D includes fuel and cladding. In this paper, only R&D related to cladding integrity will be covered. Specific areas aimed at improving fuel cladding integrity include: (1) Fuel Reliability Data Base; (2) Operational Guidance for Defective Fuel; (3) Impact of Water Chemistry on Cladding Integrity; (4) Cladding Corrosion Data and Model; (5) Cladding Mechanical Properties; and (6) Transient Fuel Cladding Response.

  5. Effect of thermal processing practices on the properties of superplastic Al-Li alloys

    Science.gov (United States)

    Hales, Stephen J.; Lippard, Henry E.

    1993-01-01

    The effect of thermal processing on the mechanical properties of superplastically formed structural components fabricated from three aluminum-lithium alloys was evaluated. The starting materials consisted of 8090, 2090, and X2095 (Weldalite(TM) 049), in the form of commercial-grade superplastic sheet. The experimental test matrix was designed to assess the impact on mechanical properties of eliminating solution heat treatment and/or cold water quenching from post-forming thermal processing. The extensive hardness and tensile property data compiled are presented as a function of aging temperature, superplastic strain and temper/quench rate for each alloy. The tensile properties of the materials following superplastic forming in two T5-type tempers are compared with the baseline T6 temper. The implications for simplifying thermal processing without degradation in properties are discussed on the basis of the results.

  6. 不锈钢铝合金半固态连接工艺参数研究%Technological parameters of stainless steel-aluminum alloy semisolid joining clad

    Institute of Scientific and Technical Information of China (English)

    刘洪伟; 郭成

    2007-01-01

    By using semisolid joining technique, the bonding of stainless steel and semisolid aluminum alloy is successfully realized. The relationships between interfacial shear strength and solid fraction of aluminum alloy, bonding pressure and time of keeping pressure were studied by the method of orthogonal experiment. The interfacial structure and the fracture structure of the bonding plate are studied by means of optical microscope (OM) and scanning electron microscope (SEM). The results show that there is the best solid fraction between the solid phase line and the liquid phase line of the semisolid aluminum alloy, with the increase of bonding pressure and pressure time, the interfacial shear strength increases rapidly, and then with further increase of bonding pressure and pressure time, the shear strength rises little. Along the interface, solid phase and liquid phase bond with stainless steel by turns because of the different diffusion ability. So, a new type of non-equilibrium diffusion interfacial structure is constructed at the interface of stainless steel and aluminum alloy, compound mechanism of plastic and brittle fracture interface was formed at the shear fracture interface.

  7. Development of Mechanical Loading Device for testing the zirconium cladding under the pellet-cladding interaction conditions

    Directory of Open Access Journals (Sweden)

    V. I. Solonin

    2014-01-01

    Full Text Available Currently, there is a tendency of transition to the long-term cycles of operation with fuel and to the new transitional modes. This fact requires extra experimental validation for design of fuel rods. New operating conditions are expanding operability requirements of claddings.To implement the experimental techniques the Mechanical Loading Device (MLD was developed, capable of providing the conditions of stress-strain state similar to the pellet-cladding interaction (PCI during operation of the reactor.Complex strain state of a fuel rod cladding is simulated by the impacting force on the plunger and then on the simulator of the fuel pellet. The simulator is made of interposer of zirconium and the inset made of ceramic - aluminum oxide. Mechanical properties of the aluminum oxide are similar to the material of the fuel pellet - uranium dioxide. Experiments conducted on the layout and the MLD as such have shown that a stress-strain state matches with that of under operating conditions of the fuel rod in the reactor.The developed device and test method allows us to simulate a wide range of reactor transient modes. Claddings can be used both in the delivered state, and with the further preparation, including the exposure in nuclear reactor. MLD design enables us to carry out experiments with the presence of an aggressive environment inside the cladding, simulating the presence of gaseous fission products in the fuel rod.For further the development of this research it is necessary to design the laboratory complex for MLD. Extra computational verification experiment is needed as well. In particular, stresses in the cladding achieved during the experiment ought to be calculated. Calculated stresses are required to make project justification on the performance capability of fuel rods.

  8. Effect of tool geometry and cutting parameters on delamination and thrust forces in drilling CFRP/Al-Li

    Science.gov (United States)

    El Bouami, Souhail; Habak, Malek; Franz, Gérald; Velasco, Raphaël; Vantomme, Pascal

    2016-10-01

    Composite materials are increasingly used for structural parts in the aeronautic industries. Carbon Fiber-Reinforced Plastics (CFRP) are often used in combination with metallic materials, mostly aluminium alloys. This raises new problems in aircraft assembly. Delamination is one of these problems. In this study, CFRP/Al-Li stacks is used as experimental material for investigation effect of interaction of cutting parameters (cutting speed and feed rate) and tool geometry on delamination and thrust forces in drilling operation. A plan of experiments, based on Taguchi design method, was employed to investigate the influence of tool geometry and in particular the point angle and cutting parameters on delamination and axial effort. The experimental results demonstrate that the feed rate is the major parameter and the importance of tool point angle in delamination and thrust forces in the stacks were shown.

  9. Estimation of isothermal sections of ternary phase diagrams of lithium containing systems: the Al--Li--Mg system

    Energy Technology Data Exchange (ETDEWEB)

    Saboungi, M. L.; Hsu, C. C.

    1976-12-01

    The method of Kaufman and coworkers is used to provide an estimate of isothermal sections of the Al--Li--Mg system. One starts by calculating the lattice stability of the constituents, the binary interaction coefficients and the binary compound parameters. In the computations, thermodynamic data, when available, were coupled with measured phase diagrams to provide thermodynamically self-consistent liquidus and solidus curves for the binary systems. Standard enthalpies of formation and entropies of formation were calculated for the reported compounds. The binary system Li--Mg illustrates the use of such calculations in selecting the most reliable representation of the phase diagram. The calculated binary data were used to compute the phase diagram of Li--Al--Mg, assuming that no ternary compounds exist. 4 tables, 7 figures, 29 references. (GHT)

  10. Study on the characteristics and thermal stability of nanostructures in adiabatic shear band of 2195 Al-Li alloy

    Science.gov (United States)

    Yang, Yang; Chen, Yadong; Jiang, Lihong; Li, Meng; Zhang, Qingming; Tang, Tiegang

    2015-11-01

    Adiabatic shear bands (ASB) were obtained by dynamic shearing with a split Hopkinson pressure bar in the hat-shaped specimens of 2195-T6 Al-Li alloy. TEM observations reveal that grains in ASB are mainly equiaxed with the grain size from 50 to 100 nm. The kinetics possibility of instant refinement of grains can well be explained with the rotation dynamic recrystallization mechanism. EBSD is used to investigate microstructure evolution in ASB after annealed at 100-400 °C for 1 h. Results show that grain size increases rapidly at higher annealing temperature, and grains grow from 0.22 μm at 300 °C to 1.77 μm at 400 °C. Microhardness measurement indicated that the microhardness value rises slowly with temperature increases and then drops quickly at 300 °C. The study indicates that the nanostructure in ASB is thermally stable below 300 °C.

  11. Structural properties and relative stability of (meta)stable ordered, partially ordered, and disordered Al-Li alloy phases

    Science.gov (United States)

    Alam, Aftab; Johnson, D. D.

    2012-04-01

    We resolve issues that have plagued reliable prediction of relative phase stability for solid solutions and compounds. Due to its commercially important phase diagram, we showcase the Al-Li system because historically density-functional theory (DFT) results show large scatter and limited success in predicting the structural properties and stability of solid solutions relative to ordered compounds. Using recent advances in an optimal basis-set representation of the topology of electronic charge density (and, hence, atomic size), we present DFT results that agree reasonably well with all known experimental data for the structural properties and formation energies of ordered, off-stoichiometric partially ordered, and disordered alloys, opening the way for reliable study in complex alloys.

  12. Fuel pin cladding

    Science.gov (United States)

    Vaidyanathan, Swaminathan; Adamson, Martyn G.

    1986-01-01

    An improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

  13. Pulsed plasma arc cladding

    Institute of Scientific and Technical Information of China (English)

    龙; 白钢; 李振民; 张赋升; 杨思乾

    2004-01-01

    A prototype of Pulsed Plasma Arc Cladding system was developed, in which single power source supplies both transferred plasma arc (TPA) and non-transferred plasma arc (N-TPA). Both plasmas work in turn in a high frequency controlled by an IGBT connecting nozzle and workpiece. The working frequency of IGBT ranges from 50 ~ 7000Hz, in which the plasmas can work in turn smoothly. Higher than 500 Hz of working frequency is suggested for promotion of cladding quality and protection of IGBT. Drag phenomenon of TPA intensifies as the frequency goes up, which tends to increase the current proportion of TPA and suppress N-TPA. The occupation ratio of IGBT can be regulated from 5% ~ 95%, which balances the power supplies of both plasmas. An occupation ratio higher than 50% gives adequate proportion of arc current for N-TPA to preheat powder.

  14. Design of multistep aging treatments of 2099 (C458) Al-Li alloy

    Science.gov (United States)

    Romios, M.; Tiraschi, R.; Ogren, J. R.; Es-Said, O. S.; Parrish, C.; Babel, H. W.

    2005-10-01

    Multistep artificial aging treatments coupled with various natural aging times for aluminum lithium 2099 alloy (previously called C458) are discussed to obtain mechanical tensile properties in the T6 condition that match those in the T861 condition, having a yield strength in the range of 414-490 MPa (60-71 ksi), an ultimate strength in the range of 496-538 MPa (72-78 ksi), and 10-13% elongation. Yield and ultimate tensile strengths from 90-100% of the strength of the as-received material (in the T861 condition) were obtained. The highest tensile strengths were consistently obtained with two-step, low-to-high temperature artificial aging treatments consisting of a first step at 120 °C (248 °F) for 12-24 h followed by a second step between 165 and 180 °C (329-356 °F) for 48-100 h. These T6-type heat treatments produced average yield and ultimate strengths in the longitudinal direction in the range of 428-472 MPa (62.1-68.5 ksi) and 487-523 MPa (70.6-75.9 ksi), respectively, as well as lower yield strength anisotropy when compared with the as-received material in the T861 condition.

  15. Russian aluminum-lithium alloys for advanced reusable spacecraft

    Science.gov (United States)

    Charette, Ray O.; Leonard, Bruce G.; Bozich, William F.; Deamer, David A.

    1998-01-01

    Cryotanks that are cost-affordable, robust, fuel-compatible, and lighter weight than current aluminum design are needed to support next-generation launch system performance and operability goals. The Boeing (McDonnell Douglas Aerospace-MDA) and NASA's Delta Clipper-Experimental Program (DC-XA) flight demonstrator test bed vehicle provided the opportunity for technology transfer of Russia's extensive experience base with weight-efficient, highly weldable aluminum-lithium (Al-Li) alloys for cryogenic tank usage. As part of NASA's overall reusable launch vehicle (RLV) program to help provide technology and operations data for use in advanced RLVs, MDA contracted with the Russian Academy of Sciences (RAS/IMASH) for design, test, and delivery of 1460 Al-Li alloy liquid oxygen (LO2) cryotanks: one for development, one for ground tests, and one for DC-XA flight tests. This paper describes the development of Al-Li 1460 alloy for reusable LO2 tanks, including alloy composition tailoring, mechanical properties database, forming, welding, chemical milling, dissimilar metal joining, corrosion protection, completed tanks proof, and qualification testing. Mechanical properties of the parent and welded materials exceeded expectations, particularly the fracture toughness, which promise excellent reuse potential. The LO2 cryotank was successfully demonstrated in DC-XA flight tests.

  16. Computer simulation of Al-Li alloy retrogression%Al-Li合金回归过程的数值模拟

    Institute of Scientific and Technical Information of China (English)

    徐国栋; 沈智

    2012-01-01

    基于离散格点形式的Langevin方程,以Al-12%Li合金为对象,模拟合金完全回归的过程。结果表明,Al-Li合金完全回归过程经过Li的固溶,δ'相的回归,δ'相的无序化;Al-Li合金完全回归,其温度需要达到一定条件才可以发生,否则即使延长回归时间,有序相也只发生部分回归;温度越高,Al-Li合金完全回归时间越短,Li含量越低,发生完全回归的温度越低。%Based on Langevin equation of the discrete format,the evolution of retrogression of Al-12%Li alloy is investigated using computer simulation.The results show that the complete retrogression process of Al-Li alloy as solution of lithium,retrogression of δ′ and disorder of δ′.Al-Li alloy could retrogress completely when the temperature was reached certain conditions,otherwise even prolonged heat treatment time,the ordered phase could partially retrogress.The higher the temperature,the shorter time of Al-Li alloy completely retrogress.The less Li content,the lower temperature of Al-Li alloy completely retrogress.

  17. Electrochemical Formation of Al-Li Alloys by Codeposition of Al and Li from LiCl-KCl-AlF3 Melts at 853 K

    Institute of Scientific and Technical Information of China (English)

    SUN Yi; ZHANG Mi-lin; HAN Wei; LI Mei; YANG Yu-sheng

    2013-01-01

    The electrochemical behavior of Al(Ⅲ) ions was studied in molten LiCl-KCl melts on a molybdenum electrode.Cyclic voltammetry,chronopotentiometry and chronoamperometry were used to explore the deposition mechanism of Al and Li.Cyclic voltammetry expriment indicates that under potential deposition(UPD) of lithium on pre-deposited aluminium led to the formation of liquid Al-Li alloys at 853 K.The diffusion coefficient of Al(Ⅲ) ions at 853 K in LiCl-KCl-AlF3(1%,mass fraction) melts was determined to be (2.79±0.05)× 10-5 cm2/s.Chronopotentiograms and chronoamperograms demonstrate that the codeposition of Al(Ⅲ) and Li(Ⅰ) ions formed Al-Li alloys at cathodic current densities higher than-0.28 A/cm2 or cathodic potentials more negative than-2.20 V.X-Ray diffraction(XRD) pattern indicates that Al-Li alloys with different phases formed via galvanostatic electrolysis.Inductively coupled plasma(ICP) analyses of the samples obtained by electrolysis show that lithium and aluminium contents of Al-Li alloys could be controlled by AlF3 concentration and current intensity.

  18. 铝基覆铜板的热阻与导热系数测量方法研究%Study on Thermal Conductivity and Resistance Measuring Method of Aluminum Based Copper Clad Laminate

    Institute of Scientific and Technical Information of China (English)

    张诗娟; 王勇涛; 王文峰

    2015-01-01

    由于热流法与激光法在测量高导热铝基覆铜板的导热系数与热阻时均存在一定的局限性,通过分析铝基板两层介质的热传导模型,提出了利用激光法的测量数据代入热传导模型中,求得铝基覆铜板实际热阻与铝基覆铜板绝缘层导热系数的新方法。该方法操作简单,且测试结果较准确。%Because the heat flow method and laser method have certain limitation in measuring the ther-mal conductivity and thermal resistance of high thermal conductivity aluminium based copper clad lami-nate(AlCCL), through analyzing the heat conduction model of AlCCL’s two layer medium, we used the measurement data of laser method to substituted in heat conduction model and the actual thermal resis-tance of AlCCL and the thermal conductivity of its insulation layer were obtained. The method has a sim-ple operation, and its test results are accurate.

  19. Aerogel-clad optical fiber

    Science.gov (United States)

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  20. The effect of zinc additions on the environmental stability of Alloy 8090 (Al-Li-Cu-Mg-Zr)

    Science.gov (United States)

    Kilmer, Raymond J.; Stoner, G. E.

    1991-01-01

    Stress corrosion cracking (SCC) remains a problem in both Al-Li and conventional Al heat treatable alloys. It has recently been found that relatively small additions (less than or approximately 1 wt-percent) of Zn can dramatically improve the SCC performance of alloy 8090 (Al-Li-Cu-Mg-Zr). Constant load time to failure experiments using cylindrical tensile samples loaded between 30 and 85 percent of TYS indicate improvements of orders of magnitude over the baseline 8090 for the Zn-containing alloys under certain aging conditions. However, the toughnesses of the alloys were noticeably degraded due to the formation of second phase particles which primarily reside on grain and subgrain boundaries. EDS revealed that these intermetallic particles were Cu and Zn rich. The particles were present in the T3 condition and were not found to be the result of quench rate, though their size and distribution were. At 5 hours at 160 C, the alloys displayed the greatest susceptibility to SCC but by 20 hours at 160 C the alloys demonstrated markedly improved TTF lifetimes. Aging past this time did not provide separable TTF results, however, the alloy toughnesses continued to worsen. Initial examination of the alloys microstructures at 5 and 20 hours indicated some changes most notably the S' and delta' distributions. A possible model by which this may occur will be explored. Polarization experiments indicated a change in the trend of E(sub BR) and passive current density at peak aging as compared to the baseline 8090. Initial pitting experiments indicated that the primary pitting mechanism in chloride environments is one occurring at constituent (Al-Fe-Cu) particles and that the Cu and Zn rich boundary precipitates posses a breakaway potential similar to that of the matrix acting neither anodic or cathodic in the first set of aerated 3.5 w/o NaCl experiments. Future work will focus on the identification of the second phase particles, evaluation of K(sub 1SCC) and plateau da/dt via

  1. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, B.J.; Kim, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-04-01

    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report 'Alloy Development for High Burnup Cladding.' Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs.

  2. Wear behavior and corrosion resistance of NiCrAl/TiC composite coating on aluminum alloy by laser cladding%铝合金表面激光熔覆NiCrAl/TiC复合涂层的磨损行为和耐蚀性能

    Institute of Scientific and Technical Information of China (English)

    李琦; 刘洪喜; 张晓伟; 姚爽; 张旭

    2014-01-01

    为提高铝合金的摩擦磨损和耐蚀性能,在A390铝合金基体上通过激光熔覆制备NiCrAl/TiC复合涂层。采用XRD和EDS分析了涂层的物相组成,结合SEM观察了涂层的微观组织,运用摩擦磨损试验机和电化学工作站测试了涂层的摩擦磨损和耐腐蚀性能。结果表明:复合涂层主要物相为AlNi、Al 3 Ni 2、TiC ,同时含有少量的Cr 13 Ni 5 Si 2、Cu 9 Al 4和α(Al)。涂层自下至上分别为短棒状树枝晶、胞状晶、柱状树枝晶和等轴晶。相同磨损条件下,A390基体发生了严重的磨粒磨损和剥层磨损,而激光熔覆涂层只产生了轻微的磨粒磨损,熔覆层的相对耐磨性为3.16。在3.5%NaCl溶液中的极化曲线和电化学阻抗谱(EIS)显示:熔覆层自腐蚀电位较A390基体的正移,腐蚀电流密度减小;熔覆层呈单容抗特性,而A390基体在高频区表现为容抗特性,在中低频区则为感抗特性。在Bote图中,低频区熔覆层对应的相位角和中低频段熔覆层的阻抗模值均大于A390基体的,表明熔覆层的耐蚀性远高于A390基体的。熔覆层的腐蚀形貌为局部点蚀,A390基体的腐蚀形貌为晶间腐蚀和剥蚀。%In order to improve the frictional wear behavior and corrosion resistance of aluminum alloy, NiCrAl/TiC composite coating was fabricated on A390 aluminum alloy by laser cladding. The phase constitution, microstructure, frictional wear behavior and corrosion resistance of the composite coating were analyzed using X-ray diffraction (XRD), energy dispersive spectrum (EDS), scanning electron microscope (SEM), friction and wear testing machine and electrochemical workstation. The results show that the coating is mainly composed of AlNi, Al 3 Ni 2 and TiC phases, and a small amount of Cr13Ni5Si2, Cu9Al4 and α(Al) phases. The microstructures of the coating from the bottom to top are dendrite crystal, cellular crystal, columnar dendrite crystal and equiaxed

  3. Reactivity Initiated Accident Simulation to Inform Transient Testing of Candidate Advanced Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicholas R [ORNL; Wysocki, Aaron J [ORNL; Terrani, Kurt A [ORNL

    2016-01-01

    Abstract. Advanced cladding materials with potentially enhanced accident tolerance will yield different light water reactor performance and safety characteristics than the present zirconium-based cladding alloys. These differences are due to different cladding material properties and responses to the transient, and to some extent, reactor physics, thermal, and hydraulic characteristics. Some of the differences in reactors physics characteristics will be driven by the fundamental properties (e.g., absorption in iron for an iron-based cladding) and others will be driven by design modifications necessitated by the candidate cladding materials (e.g., a larger fuel pellet to compensate for parasitic absorption). Potential changes in thermal hydraulic limits after transition from the current zirconium-based cladding to the advanced materials will also affect the transient response of the integral fuel. This paper leverages three-dimensional reactor core simulation capabilities to inform on appropriate experimental test conditions for candidate advanced cladding materials in a control rod ejection event. These test conditions are using three-dimensional nodal kinetics simulations of a reactivity initiated accident (RIA) in a representative state-of-the-art pressurized water reactor with both nuclear-grade iron-chromium-aluminum (FeCrAl) and silicon carbide based (SiC-SiC) cladding materials. The effort yields boundary conditions for experimental mechanical tests, specifically peak cladding strain during the power pulse following the rod ejection. The impact of candidate cladding materials on the reactor kinetics behavior of RIA progression versus reference zirconium cladding is predominantly due to differences in: (1) fuel mass/volume/specific power density, (2) spectral effects due to parasitic neutron absorption, (3) control rod worth due to hardened (or softened) spectrum, and (4) initial conditions due to power peaking and neutron transport cross sections in the

  4. Explosive Cladding of Titanium and Aluminium Alloys on the Example of Ti6Al4V-AA2519 Joints / Wybuchowe Platerowanie Stopów Tytanu I Aluminium Na Przykładzie Połączenia Ti6Al4V-AA2519

    Directory of Open Access Journals (Sweden)

    Gałka A.

    2015-12-01

    Full Text Available Explosive cladding is currently one of the basic technologies of joining metals and their alloys. It enables manufacturing of the widest range of joints and in many cases there is no alternative solution. An example of such materials are clads that include light metals such as titanium and aluminum. ach new material combination requires an appropriate adaptation of the technology by choosing adequate explosives and tuning other cladding parameters. Technology enabling explosive cladding of Ti6Al4V titanium alloy and aluminum AA2519 was developed. The clads were tested by means of destructive and nondestructive testing, analyzing integrity, strength and quality of the obtained joint.

  5. Environmental fatigue of an Al-Li-Cu alloy. Part 3: Modeling of crack tip hydrogen damage

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1992-01-01

    Environmental fatigue crack propagation rates and microscopic damage modes in Al-Li-Cu alloy 2090 (Parts 1 and 2) are described by a crack tip process zone model based on hydrogen embrittlement. Da/dN sub ENV equates to discontinuous crack advance over a distance, delta a, determined by dislocation transport of dissolved hydrogen at plastic strains above a critical value; and to the number of load cycles, delta N, required to hydrogenate process zone trap sites that fracture according to a local hydrogen concentration-tensile stress criterion. Transgranular (100) cracking occurs for process zones smaller than the subgrain size, and due to lattice decohesion or hydride formation. Intersubgranular cracking dominates when the process zone encompasses one or more subgrains so that dislocation transport provides hydrogen to strong boundary trapping sites. Multi-sloped log da/dN-log delta K behavior is produced by process zone plastic strain-hydrogen-microstructure interactions, and is determined by the DK dependent rates and proportions of each parallel cracking mode. Absolute values of the exponents and the preexponential coefficients are not predictable; however, fractographic measurements theta sub i coupled with fatigue crack propagation data for alloy 2090 established that the process zone model correctly describes fatigue crack propagation kinetics. Crack surface films hinder hydrogen uptake and reduce da/dN and alter the proportions of each fatigue crack propagation mode.

  6. Texture Evolution within the Thermomechanically Affected Zone of an Al-Li Alloy 2195 Friction Stir Weld

    Science.gov (United States)

    Tayon, Wesley A.; Domack, Marcia S.; Hoffman, Eric K.; Hales, Stephen J.

    2013-11-01

    Friction stir welding (FSW) of Al -Li alloy 2195 plate produces strong texture gradients. The microstructural characteristics evolve from the base plate, through the thermomechanically affected zone (TMAZ), to the weld nugget interface. In the current study, electron backscattered diffraction (EBSD) analyses were employed to quantify the spatial distribution of texture gradients associated with the evolution of texture within the TMAZ. The strong texture of the base plate enabled the texture evolution to be characterized as a function of location. Systematic partitioning of EBSD data relative to the degree of lattice rotation at each point accurately captured the crystallographic transitions across the advancing side TMAZ. Over a large section of this region, the texture evolves as a result of continuous rigid body rotations. The rigid body rotations were correlated with the complex material flow patterns commonly associated with the FSW process and prior observations of shear-related textures. Finally, a correlation between texture and fracture in a subscale tensile specimen is observed, where failure occurs within a visible band of low-Taylor factor grains.

  7. Three-dimensional effects of microstructures on short fatigue crack growth in an Al-Li 8090 alloy

    Science.gov (United States)

    Wen, Wei; Zhai, Tongguang

    2011-09-01

    Al-Li 8090 alloy specimens were fatigued using a self-aligning four-point bend rig at R = 0.1 and room temperature, in air, under constant maximum stress control. The crystallographic characteristics of fatigue crack initiation and early growth were studied using EBSD. It was found that the growth behaviour of a short crack were controlled by the twist (α) and tilt (β) components of crack plane deflection across each of the first 20 grain boundaries along the crack path, and that the α angle at the first grain boundary encountered by a micro-crack was critical in determining whether the crack could become propagating or non-propagating. In addition to the orientations of the two neighbouring grains, the tilt of their boundary could also affect α across the boundary. A minimum α-map for a vertical micro-crack was calculated to evaluate the resistance to crack growth into a neighbouring grain with a random orientation. Such an α-map is of value in alloy design against fatigue damage by optimising texture components in the alloys.

  8. Strain hardening and jump-like deformation of ultrafine polycrystalline Al-Li solid solutions at 0.5 K

    Science.gov (United States)

    Isaev, N. V.; Shumilin, S. E.; Zabrodin, P. A.; Geidarov, V. G.; Grigorova, T. V.; Fomenko, V. S.; Braude, I. S.; Pustovalov, V. V.

    2013-07-01

    This is a study of the effect of microstructure created by severe plastic deformation (SPD) and annealing on strain hardening and jump-like deformation in Al-Li alloys. It is shown that under tension at 0.5 K, SPD processed polycrystals retain a significant strain hardening rate and have high strength and ductility. SPD also simulates unstable (jump-like) flow of the polycrystals owing to dislocation dynamics that shows up as stress jumps in the tension curve. The average amplitude of the jumps increases with strain, while the dislocation amplitude distribution corresponds to collective motion of dislocation avalanches with a distinctive scale. Jump-like deformation is partially suppressed by high-temperature annealing, while the distribution of the jump amplitudes is described by a power law. The relationship established between the coefficient of strain hardening and the average stress jump amplitude suggests a common dislocation dynamic for strain hardening and jump-like deformation at low temperatures. The observed features of low-temperature plastic deformation are treated as a consequence of changes in the grain sizes and density of dislocations owing to SPD and annealing.

  9. Effect of Rare Earth Cerium on Yield Strength Anisotropy of Al-Li Alloy Sheet and Its Theoretical Prediction

    Institute of Scientific and Technical Information of China (English)

    赵志龙; 刘林; 陈铮

    2004-01-01

    The variation of yield strength along rolling direction, transverse direction and 45° to transverse direction of 2090 Al-Li alloy and 2090+Ce alloy sheet containing rare earth cerium was comparatively investigated. The difference of deformation texture in these two alloy sheets was analyzed by means of X-ray orientation distribution function (ODF). The results show that cerium has the effects of enhancing the Brass and S rolling texture components and reducing the recrystallized texture components of Cube and Goss. This is the reason that the anisotropic degree of yield strength in 2090+Ce sheet is higher than that of 2090 alloy sheet. The prediction of yield strength along various orientations in two alloy sheets was done based on Taylor/Bishop-Hill model, and the strengthening effect of grain boundary was evaluated using Hall-Petch relationship. A modified plastic inclusion model was proposed using the concept of grain-orientation factor and T1 phase orientation factor by fitting with tensile test results.

  10. Aluminum Nanoholes for Optical Biosensing

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2015-07-01

    Full Text Available Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (biosensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (biosensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs.

  11. Friction surface cladding: development of a solid state cladding process

    NARCIS (Netherlands)

    Stelt, van der Adrianus Anton

    2014-01-01

    Many industries including automotive, aerospace, electronics, shipbuilding, offshore, railway and heavy equipment employ surface modification technologies to change the surface properties of a manufactured product. Often, the surface is covered (coated) with a dissimilar clad layer for this purpose

  12. Pulsed Nd:YAG laser cladding of high silicon content coating on low silicon steel

    Institute of Scientific and Technical Information of China (English)

    Danyang Dong; Changsheng Liu; Bin Zhang; Jun Miao

    2007-01-01

    A pulsed Nd:YAG (yttrium aluminum garnet) laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution,within the obtained cladding coatings, were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), with associated energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The microhardness was also measured along the depth direction of the specimens. A crack- and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized single-track and multi-track laser cladding. The phases of the coating are α-Fe, γ-Fe, and FeSi. The high microhardness of the lasercladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt% in the single-track cladding and 6.5wt% in the multi-track cladding, respectively.

  13. Laser-induced reversion of $\\delta^{'}$ precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe

    CERN Document Server

    Khushaim, Muna; Al-Kassab, Talaat

    2015-01-01

    The influence of tuning the laser energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction and composition of $\\delta^{'}$ precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser energy of 100 pJ was in fairly good agreement with reported range of $\\delta^{'}$ solvus temperature, suggesting a result of reversion upon heating due to laser pulsing.

  14. Duct and cladding alloy

    Science.gov (United States)

    Korenko, Michael K.

    1983-01-01

    An austenitic alloy having good thermal stability and resistance to sodium corrosion at 700.degree. C. consists essentially of 35-45% nickel 7.5-14% chromium 0.8-3.2% molybdenum 0.3-1.0% silicon 0.2-1.0% manganese 0-0.1% zirconium 2.0-3.5% titanium 1.0-2.0% aluminum 0.02-0.1% carbon 0-0.01% boron and the balance iron.

  15. Environmental fatigue of an Al-Li-Cu alloy. I - Intrinsic crack propagation kinetics in hydrogenous environments

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1991-01-01

    Deleterious environmental effects on steady-state, intrinsic fatigue crack propagation (FCP) rates (da/dN) in peak aged Al-Li-Cu alloy 2090 are established by electrical potential monitoring of short cracks with programmed constant delta K and K(sub max) loading. The da/dN are equally unaffected by vacuum, purified helium, and oxygen but are accelerated in order of decreasing effectiveness of aqueous 1 percent NaCl with anodic polarization, pure water vapor, moist air, and NaCl with cathodic polarization. While da/dN depends on delta K(sup 4.0) for the inert gases, water vapor and chloride induced multiple power-laws, and a transition growth rate 'plateau'. Environmental effects are strongest at low delta K. Crack tip damage is ascribed to hydrogen embrittlement because of the following: (1) accelerated da/dN due to part-per-million levels of H2O without condensation; (2) impeded molecular flow model predictions of the measured water vapor pressure dependence of da/dN as affected by mean crack opening; (3) the lack of an effect of film-forming O2; (4) the likelihood for crack tip hydrogen production in NaCl; and (5) the environmental and delta K-process zone volume dependencies of the microscopic cracking modes. For NaCl, growth rates decrease with decreasing loading frequency, with the addition of passivating Li2CO3, and upon cathodic polarization. These variables increase crack surface film stability to reduce hydrogen entry efficiency. The hydrogen environmental FCP resistance of 2090 is similar to other 2000 series alloys and is better than 7075.

  16. Environmental fatigue of an Al-Li-Cu alloy. Part 1: Intrinsic crack propagation kinetics in hydrogenous environments

    Science.gov (United States)

    Piascik, Robert S.; Gangloff, Richard P.

    1991-01-01

    Deleterious environmental effects on steady-state, intrinsic fatigue crack propagation (FCP) rates (da/dN) in peak aged Al-Li-Cu alloy 2090 are established by electrical potential monitoring of short cracks with programmed constant delta K and K(sub max) loading. The da/dN are equally unaffected by vacuum, purified helium, and oxygen but are accelerated in order of decreasing effectiveness by aqueous 1 percent NaCl with anodic polarization, pure water vapor, moist air, and NaCl with cathodic polarization. While da/dN depends on delta K(sup 4.0) for the inert gases, water vapor and chloride induced multiple power-laws, and a transition growth rate 'plateau'. Environmental effects are strongest at low delta K. Crack tip damage is ascribed to hydrogen embrittlement because of the following: (1) accelerated da/dN due to part-per-million levels of H2O without condensation; (2) impeded molecular flow model predictions of the measured water vapor pressure dependence of da/dN as affected by mean crack opening; (3) the lack of an effect of film-forming O2; (4) the likelihood for crack tip hydrogen production in NaCl, and (5) the environmental and delta K-process zone volume dependencies of the microscopic cracking modes. For NaCl, growth rates decrease with decreasing loading frequency, with the addition of passivating Li2CO3, and upon cathodic polarization. These variables increase crack surface film stability to reduce hydrogen entry efficiency. The hydrogen environmental FCP resistance of 2090 is similar to other 2000 series alloys and is better than 7075.

  17. Characterization of Fuel-Cladding Bond Strength Using Laser Shock

    Energy Technology Data Exchange (ETDEWEB)

    James A. Smith; David L. Cottle; Barry H. Rabin

    2014-04-01

    This paper describes new laser-based capabilities for characterization of fuel-cladding bond strength in nuclear fuels, and presents preliminary results obtained from studies on as-fabricated monolithic fuel consisting of uranium-10 wt.% molybdenum alloys clad in 6061 aluminum by hot isostatic pressing. Two complementary experimental methods are employed, laser-shock testing and laser-ultrasonic imaging. Measurements are spatially localized, non-contacting and require minimum specimen preparation, and are therefore ideally suited for applications involving radioactive materials, including irradiated materials. The theoretical principles and experimental approaches employed in characterization of nuclear fuel plates are described. The ability to measure layer thicknesses, elastic properties of the constituents, and the location and nature of laser-shock induced debonds is demonstrated, and preliminary bond strength measurement results are discussed.

  18. Kinetics of aluminum lithium alloys

    Science.gov (United States)

    Pletcher, Ben A.

    2009-12-01

    Aluminum lithium alloys are increasingly used in aerospace for their high strength-to-weight ratio. Additions of lithium, up to 4.2 wt% decrease the alloy density while increasing the modulus and yield strength. The metastable, second phase Al3Li or delta' is intriguing, as it remains spherical and coherent with the matrix phase, alpha, well into the overaged condition. Small interfacial strain energy allows these precipitates to remain spherical for volume fractions (VV ) of delta' less than 0.3, making this alloy system ideal for investigation of late-stage coarsening phenomena. Experimental characterization of three binary Al-Li alloys are presented as a critical test of diffusion screening theory and multi-particle diffusion simulations. Quantitative transmission electron microscopy is used to image the precipitates directly using the centered dark-field technique. Images are analyzed autonomously within a novel Matlab function that determines the center and size of each precipitate. Particle size distribution, particle growth kinetics, and maximum particle size are used to track the precipitate growth and correlate with the predictions of screening theory and multi-particle diffusion simulations. This project is the first extensive study of Al-Li alloys, in over 25 years, applying modern transmission electron microscopy and image analysis techniques. Previous studies sampled but a single alloy composition, and measured far fewer precipitates. This study investigates 3 alloys with volume fractions of the delta precipitates, VV =0.1-0.27, aged at 225C for 1 to 10 days. More than 1000 precipitates were sampled per aging time, creating more statistically significant data. Experimental results are used to test the predictions based on diffusion screening theory and multi-particle aging simulations. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

  19. Fabrication and testing of U-7Mo monolithic plate fuel with Zircaloy cladding

    Science.gov (United States)

    Pasqualini, E. E.; Robinson, A. B.; Porter, D. L.; Wachs, D. M.; Finlay, M. R.

    2016-10-01

    Nuclear fuel designs are being developed to replace highly enriched fuel used in research and test reactors with fuels of low enrichment. In the most challenging cases, U-(7-10 wt%)Mo monolithic plate fuels are proposed. One of the considered designs includes aluminum-alloy cladding, which provides some challenges in fabrication and fuel/cladding interaction during service. Zircaloy cladding, specifically Zry-4, was investigated as an alternative cladding, and development of a fabrication method was performed by researchers with the Comisión Nacionalde Energia Atómica (CNEA) in Argentina, resulting in test fuel plates (Zry-4 clad U-7Mo) which were subsequently tested in the Advanced Test Reactor in Idaho. Because Zry-4 and U-(7-10)Mo have similar high-temperature mechanical properties, fabrication was simplified in that the fuel foil and cladding could be co-rolled and bonded. The challenge was to prevent a thermal-expansion mismatch, which could destroy the fuel/cladding bond before complete bonding was achieved; the solution was to prevent the composites from cooling significantly during or between roll passes. The final product performed very well in-reactor, showing good bonding, very little fuel/cladding interaction-either from fabrication or in-reactor testing-and little swelling, especially no detectable heterogeneous bubble formation at the fuel/cladding interface tested to a fission density of up to 2.7E+21 (average) fissions/cm3, 3.8E+21 (peak).

  20. Double Clad Er-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    FU Yong-jun; MAO Xiang-qiao; WEI Huai; LI jian

    2007-01-01

    Presented is a theoretical study of double-clad Er-doped fiber power amplifier(EDFA). Two kinds of double clad fibers(DCF) with rectangular and "flower" inner clad shapes are studied, and these fibers have different coupling constants and propagation losses. We calculate the effective pump power absorption ratio along the fiber with different coupling constants from the first cladding to the doped core and with different propagation losses for the power in the inner cladding. Then the gains of the double clad Er-doped fiber amplifiers versus fiber lengths are calculated using the EDFA model based on propagation and rate equations of a homogeneous, two-level medium.

  1. Preliminary Investigation of Zircaloy-4 as a Research Reactor Cladding Material

    Energy Technology Data Exchange (ETDEWEB)

    Brian K Castle

    2012-05-01

    As part of a scoping study for the ATR fuel conversion project, an initial comparison of the material properties of Zircaloy-4 and Aluminum-6061 (T6 and O-temper) is performed to provide a preliminary evaluation of Zircaloy-4 for possible inclusion as a candidate cladding material for ATR fuel elements. The current fuel design for the ATR uses Aluminum 6061 (T6 and O temper) as a cladding and structural material in the fuel element and to date, no fuel failures have been reported. Based on this successful and longstanding operating history, Zircaloy-4 properties will be evaluated against the material properties for aluminum-6061. The preliminary investigation will focus on a comparison of density, oxidation rates, water chemistry requirements, mechanical properties, thermal properties, and neutronic properties.

  2. Micromechanical models of delamination in aluminum-lithium alloys

    Science.gov (United States)

    Messner, Mark Christian

    Aluminum lithium (Al-Li) alloys are lighter, stiffer, and tougher than conventional aerospace aluminum alloys. Replacing conventional aluminums with Al-Li could substantially decrease the weight and cost of aerospace structures. However, Al-Li alloys often fracture intergranularly via a mechanism called delamination cracking. While secondary delamination cracks can improve the effective toughness of a component, no current model accurately predicts the initiation and growth of intergranular cracks. Since simulations cannot incorporate delamination into a structural model, designers cannot quantify the effect of delamination cracking on a particular component. This uncertainty limits the application of Al-Li alloys. Previous experiments identify microstructural features linked to delamination. Fractography of failed surfaces indicates plastic void growth triggers intergranular failure. Furthermore, certain types of soft/stiff grain boundaries tend to localize void growth and nucleate delamination cracks. This dissertation develops a mechanism for the initiation of delamination on the microscale that accounts for these experimental observations. Microscale simulations of grain boundaries near a long primary crack explore the delamination mechanism on the mesoscale. In these simulations, a physically-based crystal plasticity (CP) model represents the constitutive response of individual grains. This CP model incorporates plastic voriticity correction terms into a standard objective stress rate integration, to accurately account for the kinematics of lattice deformation. The CP model implements slip system hardening with a modular approach to facilitate quick testing and calibration of different theories of hardening. The microscale models reveal soft/stiff grain boundaries develop elevated mean stress and plastic strain as a consequence of the mechanics of the interface. These elevated stresses and strain drive plastic void growth. The results indicate plastic void

  3. U-Mo Foil/Cladding Interactions in Friction Stir Welded Monolithic RERTR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    D.D. Keiser; J.F. Jue; C.R. Clark

    2006-10-01

    Interaction between U-Mo fuel and Al has proven to dramatically impact the overall irradiation performance of RERTR dispersion fuels. It is of interest to better understand how similar interactions may affect the performance of monolithic fuel plates, where a uranium alloy fuel is sandwiched between aluminum alloy cladding. The monolithic fuel plate removes the fuel matrix entirely, which reduces the total surface area of the fuel that is available to react with the aluminum and moves the interface between the fuel and cladding to a colder region of the fuel plate. One of the major fabrication techniques for producing monolithic fuel plates is friction stir welding. This paper will discuss the interactions that can occur between the U-Mo foil and 6061 Al cladding when applying this fabrication technique. It has been determined that the time at high temperatures should be limited as much as is possible during fabrication or any post-fabrication treatment to reduce as much as possible the interactions between the foil and cladding. Without careful control of the fabrication process, significant interaction between the U-Mo foil and Al alloy cladding can result. The reaction layers produced from such interactions can exhibit notably different morphologies vis-à-vis those typically observed for dispersion fuels.

  4. Surface Modification of Mild Steel Using Tungsten Inert Gas Torch Surface Cladding

    Directory of Open Access Journals (Sweden)

    S. Dyuti

    2010-01-01

    Full Text Available Problem statement: There is an increasing demand for claddings which possess an optimized combination of different functional properties such as high hardness, high resistance to wear and oxidation. In this respect, hard TiAlN cladding has gained much attention. These claddings can be suitable replacements for the conventional ceramic coatings applied in many components of chemical plants and automotive industries to protect against high temperature oxidation and wear. Approach: In this study the possibility of the formation of intermetallic and nitride claddings on plain carbon steel surfaces by in situ melting of preplaced titanium and aluminum powder mixture under Tungsten Inert Gas (TIG torch had been investigated. Results: Addition of 1.3 and 1.8 mg mm-2 Ti and Al powder and melting at energy inputs between 540-675 J mm-1 in nitrogen environment successfully created more than 1 mm thick clad layer consisting of a mixture of titanium-aluminum nitrides and aluminides. All resolidified melt layers produced dendrite microstructures; the dendrite concentration is more near the surface area compared to the deeper melt depth. A maximum surface hardness of around 900 Hv was developed in most of the tracks and this hardness corresponds to high concentration of dendrites within the modified layer. Oxidation at 600°C for 72 h, of the clad steel gave weight gains of 0.13 mg mm-2, compared to 0.37 mg mm-2 for the substrate. Conclusion: The results showed that clad steel gave better mechanical and oxidation properties compared to plain carbon steel substrate.

  5. Friction surface cladding: An exploratory study of a new solid state cladding process

    NARCIS (Netherlands)

    Liu, S.J.; Bor, T.C.; Stelt, van der A.A.; Geijselaers, H.J.M.; Kwakernaak, C.; Kooijman, A.M.; Mol, J.M.C.; Akkerman, R.; Boogaard, van den A.H.

    2015-01-01

    Friction surface cladding is a newly developed solid state cladding process to manufacture thin metallic layers on a substrate. In this study the influence of process conditions on the clad layer appearance and the mechanical properties of both the clad layer and the substrate were investigated. Thi

  6. Clad Degradation - FEPs Screening Arguments

    Energy Technology Data Exchange (ETDEWEB)

    E. Siegmann

    2004-03-17

    The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796]).

  7. Reliable Copper and Aluminum Connections for High Power Applications in Electromobility

    Science.gov (United States)

    Hofmann, Konstantin; Holzer, Matthias; Hugger, Florian; Roth, Stephan; Schmidt, Michael

    Investigations concerning the growth of intermetallic phases during the heat input both at the diffusion annealing of copper aluminum roll claddings and the subsequent welding process of copper-aluminum connections by using roll cladded inserts are compared to the analytical determination of phase growth. The temperature distribution in the cladding interface has been determined by thermal simulation, in order to calculate the growth of the intermetallic phases. A comparison between the width of the phases in the analytical calculation and the experiment is achieved. In consideration of high welding speeds, the energy input during the welding process is appraised in order to grade the growth of intermetallic phases. Furthermore the prevention of damage in the roll cladding interface by means of unadapted material thicknesses or welding parameters can be assessed analytically and numerically. The numerical simulations can determine the critical thickness of the roll cladding to avoid damage like exceeding growth of intermetallic phases.

  8. ZIRCONIUM-CLADDING OF THORIUM

    Science.gov (United States)

    Beaver, R.J.

    1961-11-21

    A method of cladding thorium with zirconium is described. The quality of the bond achieved between thorium and zirconium by hot-rolling is improved by inserting and melting a thorium-zirconium alloy foil between the two materials prior to rolling. (AEC)

  9. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

  10. Aluminum Target Dissolution in Support of the Pu-238 Program

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, Joanna [ORNL; Benker, Dennis [ORNL; DePaoli, David W [ORNL; Felker, Leslie Kevin [ORNL; Mattus, Catherine H [ORNL

    2014-09-01

    Selection of an aluminum alloy for target cladding affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the caustic dissolution step, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. We present a study to maximize dissolution of aluminum metal alloy, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. These data have been compared with published calculations of aluminum phase diagrams. Temperature logging during the transients has been investigated as a means to generate kinetic and mass transport data on the dissolution process. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.

  11. Laser-induced reversion of δ′ precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe

    KAUST Repository

    Khushaim, Muna Saeed Amin

    2016-06-14

    The influence of tuning the laser pulse energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction, and composition of δ\\' precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser pulse energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser pulse energy of 100 pJ was in fairly good agreement with reported range of δ\\' solvus temperature, suggesting a result of reversion upon heating due to laser pulsing. © 2016 Wiley Periodicals, Inc.

  12. Laser-induced reversion of δ' precipitates in an Al-Li alloy: Study on temperature rise in pulsed laser atom probe.

    Science.gov (United States)

    Khushaim, Muna; Gemma, Ryota; Al-Kassab, Talaat

    2016-08-01

    The influence of tuning the laser pulse energy during the analyses on the resulting microstructure in a specimen utilizing an ultra-fast laser assisted atom probe was demonstrated by a case study of a binary Al-Li alloy. The decomposition parameters, such as the size, number density, volume fraction, and composition of δ' precipitates, were carefully monitored after each analysis. A simple model was employed to estimate the corresponding specimen temperature for each value of the laser energy. The results indicated that the corresponding temperatures for the laser pulse energy in the range of 10 to 80 pJ are located inside the miscibility gap of the binary Al-Li phase diagram and fall into the metastable equilibrium field. In addition, the corresponding temperature for a laser pulse energy of 100 pJ was in fairly good agreement with reported range of  δ' solvus temperature, suggesting a result of reversion upon heating due to laser pulsing. Microsc. Res. Tech. 79:727-737, 2016. © 2016 Wiley Periodicals, Inc.

  13. Development of Aluminum-Lithium 2195 Gores by the Stretch Forming Process

    Science.gov (United States)

    Volz, M. P.; Chen, P. S.; Gorti, S.; Salvail, P.

    2014-01-01

    Aluminum-Lithium alloy 2195 exhibits higher mechanical properties and lower density than aluminum alloy 2219, which is the current baseline material for Space Launch System (SLS) cryogenic tank components. Replacement of Al 2219 with Al-Li 2195 would result in substantial weight savings, as was the case when this replacement was made on the shuttle external tank. A key component of cryogenic tanks are the gores, which are welded together to make the rounded ends of the tanks. The required thicknesses of these gores depend on the specific SLS configuration and may exceed the current experience base in the manufacture of such gores by the stretch forming process. Here we describe the steps taken to enhance the formability of Al-Li 2195 by optimizing the heat treatment and stretch forming processes for gore thicknesses up to 0.75", which envelopes the maximum expected gore thicknesses for SLS tanks. An annealing treatment, developed at Marshall Space Flight Center, increased the forming range and strain hardening exponent of Al-Li 2195 plates. Using this annealing treatment, one 0.525" thick and two 0.75" thick gores were manufactured by the stretch forming process. The annealing treatment enabled the stretch forming of the largest ever cross sectional area (thickness x width) of an Al-Li 2195 plate achieved by the manufacturer. Mechanical testing of the gores showed greater than expected ultimate tensile strength, yield strength, modulus, and elongation values. The gores also exhibited acceptable fracture toughness at room and LN2 temperatures. All of the measured data indicate that the stretch formed gores have sufficient material properties to be used in flight domes.

  14. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl-cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl, and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  15. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  16. Aluminum cladding oxidation of prefilmed in-pile fueled experiments

    Science.gov (United States)

    Marcum, W. R.; Wachs, D. M.; Robinson, A. B.; Lillo, M. A.

    2016-04-01

    A series of fueled irradiation experiments were recently completed within the Advanced Test Reactor Full size plate In center flux trap Position (AFIP) and Gas Test Loop (GTL) campaigns. The conduct of the AFIP experiments supports ongoing efforts within the global threat reduction initiative (GTRI) to qualify a new ultra-high loading density low enriched uranium-molybdenum fuel. This study details the characterization of oxide growth on the fueled AFIP experiments and cross-correlates the empirically measured oxide thickness values to existing oxide growth correlations and convective heat transfer correlations that have traditionally been utilized for such an application. This study adds new and valuable empirical data to the scientific community with respect to oxide growth measurements of highly irradiated experiments, of which there is presently very limited data. Additionally, the predicted oxide thickness values are reconstructed to produce an oxide thickness distribution across the length of each fueled experiment (a new application and presentation of information that has not previously been obtainable in open literature); the predicted distributions are compared against experimental data and in general agree well with the exception of select outliers.

  17. Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-03-02

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan (Barnes and Voke 2006). The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Hanford Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP RPP WTP 467 (Fiskum et al. 2007), eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan. • Characterizing the homogenized sample groups. • Performing parametric leaching testing on each group for compounds of interest. • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on a filtration/leaching test performed using two of the eight waste composite samples. The sample groups examined in this report were the plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR). Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, thus requiring caustic leaching. WTP RPT 167 (Snow et al. 2008) describes the homogenization, characterization, and parametric leaching activities before benchtop filtration/leaching testing of these two waste groups. Characterization and initial parametric data in that report were used to plan a single filtration/leaching test using a blend of both wastes. The test focused on filtration testing of the waste and caustic leaching for aluminum, in the form

  18. CLAD DEGRADATION - FEPS SCREENING ARGUMENTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2004-10-21

    The purpose of this report is to evaluate and document the screening of the clad degradation features, events, and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment-License Application (TSPA-LA). This report also addresses the effect of certain FEPs on both the cladding and the commercial spent nuclear fuel (CSNF), DOE-owned spent nuclear fuel (DSNF), and defense high-level waste (DHLW) waste forms, as appropriate to address the effects on multiple materials and both components (FEPs 2.1.09.09.0A, 2.1.09.11.0A, 2.1.11.05.0A, 2.1.12.02.0A, and 2.1.12.03.0A). These FEPs are expected to affect the repository performance during the postclosure regulatory period of 10,000 years after permanent closure. Table 1-1 provides the list of cladding FEPs, including their screening decisions (include or exclude). The primary purpose of this report is to identify and document the analysis, screening decision, and TSPA-LA disposition (for included FEPs) or screening argument (for excluded FEPs) for these FEPs related to clad degradation. In some cases, where a FEP covers multiple technical areas and is shared with other FEP reports, this report may provide only a partial technical basis for the screening of the FEP. The full technical basis for shared FEPs is addressed collectively by the sharing FEP reports. The screening decisions and associated TSPA-LA dispositions or screening arguments from all of the FEP reports are cataloged in a project-specific FEPs database.

  19. The influence of cladding on fission gas release from irradiated U-Mo monolithic fuel

    Science.gov (United States)

    Burkes, Douglas E.; Casella, Amanda J.; Casella, Andrew M.

    2017-04-01

    The monolithic uranium-molybdenum (U-Mo) alloy has been proposed as a fuel design capable of converting the world's highest power research reactors from use of high enriched uranium to low enriched uranium. However, a zirconium (Zr) diffusion barrier must be used to eliminate interactions that form between the U-Mo monolith and aluminum alloy 6061 (AA6061) cladding during fabrication and are enhanced during irradiation. One aspect of fuel development and qualification is to demonstrate an appropriate understanding of the extent of fission product release from the fuel under anticipated service environments. An exothermic reaction has previously been observed between the AA6061 cladding and Zr diffusion layer. In this paper, two fuel segments with different irradiation history were subjected to specified thermal profiles under a controlled atmosphere using a thermogravimetric/differential thermal analyzer coupled with a mass spectrometer inside a hot cell. Samples from each segment were tested with cladding and without cladding to investigate the effect, if any, that the exothermic reaction has on fission gas release mechanisms. Measurements revealed there is an instantaneous effect of the cladding/Zr exothermic reaction, but not necessarily a cumulative effect above approximately 973 K (700 °C). The mechanisms responsible for fission gas release events are discussed.

  20. Development on Laser Cladding Ceramic Coating

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The latest progress and research status of laser cladding ceramic coating was summarized. Technique characteristics and influence factors of laser cladding technique were introduced. Laser cladding technique includes the mixing method and laser irradiation. The mixing method can be classified as pre-coating method and synchronization method. The technique parameters include size of facula, scanning speed, cladding sector and times, adding quantity of powder, thickness of coating and quantity of joint coating. The results show that proper technique parameters can be controlled in order to acquire high quality laser cladding coating. Strengthened effect mechanism of rare earth additive is concluded, and the main effects of rare earth additive are micro-alloying, purifying boundary, fining crystal grains, improving crystal boundary, restraining columnar crystal growing. The development of laser cladding ceramic coating research was discussed.

  1. Modelling cladding response to changing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tulkki, Ville; Ikonen, Timo [VTT Technical Research Centre of Finland ltd (Finland)

    2016-11-15

    The cladding of the nuclear fuel is subjected to varying conditions during fuel reactor life. Load drops and reversals can be modelled by taking cladding viscoelastic behaviour into account. Viscoelastic contribution to the deformation of metals is usually considered small enough to be ignored, and in many applications it merely contributes to the primary part of the creep curve. With nuclear fuel cladding the high temperature and irradiation as well as the need to analyse the variable load all emphasise the need to also inspect the viscoelasticity of the cladding.

  2. Advanced Fuels Campaign Cladding & Coatings Meeting Summary

    Energy Technology Data Exchange (ETDEWEB)

    Not Listed

    2013-03-01

    The Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) organized a Cladding and Coatings operational meeting February 12-13, 2013, at Oak Ridge National Laboratory (ORNL). Representatives from the U.S. Department of Energy (DOE), national laboratories, industry, and universities attended the two-day meeting. The purpose of the meeting was to discuss advanced cladding and cladding coating research and development (R&D); review experimental testing capabilities for assessing accident tolerant fuels; and review industry/university plans and experience in light water reactor (LWR) cladding and coating R&D.

  3. Plasmonic waveguides with hyperbolic multilayer cladding

    CERN Document Server

    Babicheva, Viktoriia E; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2014-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

  4. Effect of equal channel angular extrusion on the microstructure and superplasticity of an Al-Li alloy

    Science.gov (United States)

    Salem, H. G.; Lyons, J. S.

    2002-08-01

    This research investigates the use of equal channel angular extrusion (ECAE) processing to produce a superplastic form of the aluminum alloy 2098. The starting material was a hot-rolled and precipitation-hardened plate with elongated grains of width 67-92 µm, and a composition in weight percent of 2.2% Li, 1.3% Cu, 0.73% Mg, 0.05% Zr, balance Al. Microstructural evolution was investigated with optical and transmission electron microscopy (TEM) and microhardness measurements after each step of a multipass ECAE process. ECAE produced a submicron grain structure with an average size of about 0.5 µm. The sub-grain microstructure size was a function of the magnitude of the input strain and the extrusion temperature. Misorientation angles of the developed submicron structure increase with increasing number of passes at warm working temperatures. Superplastic behavior of the ECAE-processed alloy was achieved. However, the low zirconium content of the 2098 alloy resulted in grain growth of the refined structure at the superplastic processing temperatures, placing a lower limit on the deformation rates that can be used.

  5. Co-strengthening contribution of δ' and T1 precipitates in Al-Li alloys 2090 and 2090+Ce

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhilong; LIU Lin; CHEN Zheng

    2006-01-01

    The microstructure of dislocation in two kinds of aluminum-lithium alloys 2090 and 2090 + Ce was observed by means of TEM technology. The contributions of δ' and T1 precipitates to strength were separately calculated by using the results of quantitative metallography and analysis of micro-deformation behavior; the co-strengthening effect of δ' and T1precipitates was studied. The results show that the adding relationship of co-strengthening of δ' and T1 is in accordance with q = 1.4 form at the near peak-aged condition, i.e., △τ1.4 p = △τ1.4 δ' + △τ1.4 T1; but the adding relationship is approximately a linear relation (q = 1) at the under-aged condition and becomes the parabola form when over-aged (q = 2). The adding relationship of co-strengthening contribution of δ' and T1 is obviously dependent on aging time.

  6. Rigorous modeling of cladding modes in photonic crystal fibers

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Bang, Ole

    We study the cladding modes of a photonic crystal fiber (PCF) with a finite size cladding using a finite element method. The cladding consists of seven rings of air holes with bulk silica outside.......We study the cladding modes of a photonic crystal fiber (PCF) with a finite size cladding using a finite element method. The cladding consists of seven rings of air holes with bulk silica outside....

  7. Engineering wear-resistant surfaces in automotive aluminum

    Science.gov (United States)

    Kavorkijan, V.

    2003-02-01

    Inadequate wear resistance and low seizure loads prevent the direct use of aluminum alloys in automotive parts subject to intensive friction combined with high thermal and mechanical loading, such as brake discs, pistons, and cylinder liners. To enable the use of aluminum alloys in the production of automotive brake discs and other wear-resistant products, the insertion of a monolithic friction cladding rather than surface coating has been considered in this work. Three experimental approaches, two based on the pressure-less infiltration of porous ceramic preforms and one based on the subsequent hot rolling of aluminum and metal-matrix composite strips, are currently under investigation.

  8. Inversion Solidification Cladding of H90-Steel

    Institute of Scientific and Technical Information of China (English)

    LI Bao-mian; XU Guang-ming; CUI Jian-zhong

    2008-01-01

    The variation law of cladding thickness as well as the structures and properties of H90-steel clad strip produced by inversion solidification was studied.The interface bonding mechanisms were approached.It is found that the thickness of H90 cladding goes sequentially through the solidification growth stage,holding stage,and remelting stage,with an increase in immersion time.The higher the preheating temperature of the steel coil,the thicker is the maximum cladding thickness.Observation by using optical microscopy (OM) and the electron probe microanalyzer (EPMA) shows that the microstrueture of H90 cladding is composed of equiaxed grains,and that interdiffusion between Cu and Fe at interface occurs but obvious diffusion of Zn and the intermetallic layer are not observed.The diffusion layer is thin and about 4 μm.Multipass small reduction cold rolling and repeated bending tests show that the interface is firmly bonded.Tensile test shows that the mechanical properties of the as-clad strips can meet the requirements of GB5213-2001 for the F-grade deep-drawing steel plate though there is a slight difference in the mechanical properties among the clad strips with different cladding thickness.

  9. Nuclear fuel elements having a composite cladding

    Science.gov (United States)

    Gordon, Gerald M.; Cowan, II, Robert L.; Davies, John H.

    1983-09-20

    An improved nuclear fuel element is disclosed for use in the core of nuclear reactors. The improved nuclear fuel element has a composite cladding of an outer portion forming a substrate having on the inside surface a metal layer selected from the group consisting of copper, nickel, iron and alloys of the foregoing with a gap between the composite cladding and the core of nuclear fuel. The nuclear fuel element comprises a container of the elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel material retaining means positioned in the cavity. The metal layer of the composite cladding prevents perforations or failures in the cladding substrate from stress corrosion cracking or from fuel pellet-cladding interaction or both. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy.

  10. Cladding Alloys for Fluoride Salt Compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Wilson, Dane F [ORNL; Walker, Larry R [ORNL; Santella, Michael L [ORNL; Holcomb, David Eugene [ORNL

    2011-06-01

    This report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for cladding large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high-power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for cladding inaccessible surfaces such as the interior surfaces of heat exchangers. An initial evaluation for performed on the quality of nickel claddings processed using the two selected cladding techniques.

  11. КВАЗИБИНАРНЫЕ РАЗРЕЗЫ И ПРОЕКЦИЯ ЛИКВИДУСА СИСТЕМЫ AL-LI-AL2CE

    OpenAIRE

    2006-01-01

    We have created ligvidus surface projection and equilibrium diagram of the system Al-Li-Al2Се using the method of different and thermal analysis of some polythermal sections of Al-Li-Al2Се.

  12. Advanced powder metallurgy aluminum alloys via rapid solidification technology, phase 2

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

    Marko's rapid solidification technology was applied to processing high strength aluminum alloys. Four classes of alloys, namely, Al-Li based (class 1), 2124 type (class 2), high temperature Al-Fe-Mo (class 3), and PM X7091 type (class 4) alloy, were produced as melt-spun ribbons. The ribbons were pulverized, cold compacted, hot-degassed, and consolidated through single or double stage extrusion. The mechanical properties of all four classes of alloys were measured at room and elevated temperatures and their microstructures were investigated optically and through electron microscopy. The microstructure of class 1 Al-Li-Mg alloy was predominantly unrecrystallized due to Zr addition. Yield strengths to the order of 50 Ksi were obtained, but tensile elongation in most cases remained below 2 percent. The class 2 alloys were modified composition of 2124 aluminum alloy, through addition of 0.6 weight percent Zr and 1 weight percent Ni. Nickel addition gave rise to a fine dispersion of intermetallic particles resisting coarsening during elevated temperature exposure. The class 2 alloy showed good combination of tensile strength and ductility and retained high strength after 1000 hour exposure at 177 C. The class 3 Al-Fe-Mo alloy showed high strength and good ductility both at room and high temperatures. The yield and tensile strength of class 4 alloy exceeded those of the commercial 7075 aluminum alloy.

  13. Cascaded-cladding-pumped cascaded Raman fiber amplifier.

    Science.gov (United States)

    Jiang, Huawei; Zhang, Lei; Feng, Yan

    2015-06-01

    The conversion efficiency of double-clad Raman fiber laser is limited by the cladding-to-core area ratio. To get high conversion efficiency, the inner-cladding-to-core area ratio has to be less than about 8, which limits the brightness enhancement. To overcome the problem, a cascaded-cladding-pumped cascaded Raman fiber laser with multiple-clad fiber as the Raman gain medium is proposed. A theoretical model of Raman fiber amplifier with multiple-clad fiber is developed, and numerical simulation proves that the proposed scheme can improve the conversion efficiency and brightness enhancement of cladding pumped Raman fiber laser.

  14. Surface protection of light metals by one-step laser cladding with oxide ceramics

    Science.gov (United States)

    Nowotny, S.; Richter, A.; Tangermann, K.

    1999-06-01

    Today, intricate problems of surface treatment can be solved through precision cladding using advanced laser technology. Metallic and carbide coatings have been produced with high-power lasers for years, and current investigations show that laser cladding is also a promising technique for the production of dense and precisely localized ceramic layers. In the present work, powders based on Al2O3 and ZrO2 were used to clad aluminum and titanium light alloys. The compact layers are up to 1 mm thick and show a nonporous cast structure as well as a homogeneous network of vertical cracks. The high adhesive strength is due to several chemical and mechanical bonding mechanisms and can exceed that of plasmasprayed coatings. Compared to thermal spray techniques, the material deposition is strictly focused onto small functional areas of the workpiece. Thus, being a precision technique, laser cladding is not recommended for large-area coatings. Examples of applications are turbine components and filigree parts of pump casings.

  15. Metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, Nina

    This work concerns planar optical waveguide sensors for biosensing applications, with the focus on deep-probe sensing for micron-scale biological objects like bacteria and whole cells. In the last two decades planar metal-clad waveguides have been brieflyintroduced in the literature applied...... for various biosensing applications, however a thorough study of the sensor configurations has not been presented, but is the main subject of this thesis. Optical sensors are generally well suited for bio-sensing asthey show high sensitivity and give an immediate response for minute changes in the refractive...... index of a sample, due to the high sensitivity of optical bio-sensors detection of non-labeled biological objects can be performed. The majority of opticalsensors presented in the literature and commercially available optical sensors are based on evanescent wave sensing, however most of these sensors...

  16. Testing of uranium nitride fuel in T-111 cladding at 1200 K cladding temperature

    Science.gov (United States)

    Rohal, R. G.; Tambling, T. N.; Smith, R. L.

    1973-01-01

    Two groups of six fuel pins each were assembled, encapsulated, and irradiated in the Plum Brook Reactor. The fuel pins employed uranium mononitride (UN) in a tantalum alloy clad. The first group of fuel pins was irradiated for 1500 hours to a maximum burnup of 0.7-atom-percent uranium. The second group of fuel pins was irradiated for about 3000 hours to a maximum burnup of 1.0-atom-percent uranium. The average clad surface temperature during irradiation of both groups of fuel pins was approximately 1200 K. The postirradiation examination revealed the following: no clad failures or fuel swelling occurred; less than 1 percent of the fission gases escaped from the fuel; and the clad of the first group of fuel pins experienced clad embrittlement whereas the second group, which had modified assembly and fabrication procedures to minimize contamination, had a ductile clad after irradiation.

  17. CALCULATION OF STRESS AND DEFORMATION IN FUEL ROD CLADDING DURING PELLET-CLADDING INTERACTION

    Directory of Open Access Journals (Sweden)

    Dávid Halabuk

    2015-12-01

    Full Text Available The elementary parts of every fuel assembly, and thus of the reactor core, are fuel rods. The main function of cladding is hermetic separation of nuclear fuel from coolant. The fuel rod works in very specific and difficult conditions, so there are high requirements on its reliability and safety. During irradiation of fuel rods, a state may occur when fuel pellet and cladding interact. This state is followed by changes of stress and deformations in the fuel cladding. The article is focused on stress and deformation analysis of fuel cladding, where two fuels are compared: a fresh one and a spent one, which is in contact with cladding. The calculations are done for 4 different shapes of fuel pellets. It is possible to evaluate which shape of fuel pellet is the most appropriate in consideration of stress and deformation forming in fuel cladding, axial dilatation of fuel, and radial temperature distribution in the fuel rod, based on the obtained results.

  18. Texture Dependent Young's Modulus in Austenitic Cladding

    OpenAIRE

    1988-01-01

    In Austenitic claddings of pressure vessel steel columnar grains with a 〈100〉-fiber axis oriented perpendicular to the surface have been previously observed. The fiber axis is parallel to the steepest temperature gradient. Since high temperature gradients also exist in the plane of cladding, preferred orientation should be found there.This was proved with {111}- and {220}-pole figures taken of the cladding in addition to {200}-pole figures. From these pole figures it could be concluded that t...

  19. Coupling between counterpropagating cladding modes in fiber Bragg gratings.

    Science.gov (United States)

    Sáez-Rodriguez, D; Cruz, J L; Díez, A; Andrés, M V

    2011-04-15

    We present an experimental demonstration of energy transfer between counterpropagating cladding modes in a fiber Bragg grating (FBG). A strong FBG written in a standard photosensitive optical fiber is illuminated with a single cladding mode, and the power transferred between the forward propagating cladding mode and different backward propagating cladding modes is measured by using two auxiliary long period gratings. Resonances between cladding modes having 30 pm bandwidth and 8 dB rejection have been observed.

  20. Effect of T6I6 and its modified processes on mechanical properties of novel high strength Al-Li alloy-2A97

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhi-shan; LU Zheng; XIE You-hua; WU Xiu-liang; DAI Sheng-long; LIU Chang-sheng

    2006-01-01

    Based on a novel high strength Al-Cu-Li-X alloy-2A97, the effect of T6I6 and its modified processes on the properties investigated by SEM and tensile test. The results show that when the alloy is heat treated by triple ageing, with secondary low temperature ageing at 80 ℃ after initial ageing at 155 and 150 ℃, and final re-ageing at 135 and 165 ℃, the tensile properties are close to the peak level of aged alloy in T6 temper. The addition of plastic deformation after and prior to secondary ageing favor the T1(Al2CuLi) and δ'(Al3Li) precipitation during final re-ageing at 135 and 165 ℃ corresponding to triple ageing, so the Al-Li alloy displays higher strength for the modified processes of T6I6. The microstructures consist of δ', T1 and θ"/θ' (Al2Cu) phase for single and triple aged alloy, the number density and volume fraction of δ' phase increase for T6I6 and its modified processes correspond to single ageing.

  1. The effect of vibrational entropy on the solubility and stability of ordered Al3Li phases in Al-Li alloys

    Science.gov (United States)

    Mao, Zugang; Seidman, David N.; Wolverton, C.

    2013-10-01

    The solubility and stability of three possible ordered Al3Li structures in Al-Li alloys are studied using first-principles calculations: δ'-Al3Li(L12), δ-Al3Li(DO22), and β-Al3Li(DO3). We find that δ'-Al3Li(L12) is the most stable phase and β-Al3Li(DO3) is energetically unfavorable. The vibrational formation entropy makes a significant contribution to the solubility for all three ordered Al3Li structures and yields a 1.6-fold increase in the calculated solubility of δ'-Al3Li(L12), a 1.8-fold increase for δ-Al3Li(DO22), and a 2.5-fold increase for β-Al3Li(DO3). The solubility of δ'-Al3Li(L12) is greater than those of δ-Al3Li(DO22) and β-Al3Li(DO3), and the δ'-Al3Li(L12) solvus curve is in good agreement with the experimental one.

  2. Localization of plastic deformation in ultra-fine grained Al and Al-Li at temperatures of 4.2-350 K

    Science.gov (United States)

    Isaev, N. V.; Zabrodin, P. A.; Rusakova, A. V.

    2012-10-01

    This is a study of the plasticity of coarse-grained and ultrafine-grained Al and Al-Li obtained by severe plastic deformation. The temperature dependences of the uniform deformation ɛu(T) before it is localized as necking are examined in the light of the evolution of the density of dislocations and the effect of grain boundaries. The reduction in ɛu with rising temperature is caused by an increase in the rate of annihilation of screw dislocations, which is determined by the Seeger transverse shear stress. The sharp drop in ɛu for ultrafine-grained materials compared to coarse-grained materials is explained by an increase in their yield stress and a lower rate of work hardening owing to the enhanced role of grain boundaries as obstacles, sources, and sinks for dislocations. In this case, the deformation and microhardness distributions along the sample become highly nonuniform, and, as a measure of plasticity, ɛu no longer characterizes the high local plasticity of these materials.

  3. Reduction of Liquid Clad Formation Due to Solid State Diffusion in Clad Brazing Sheet

    Science.gov (United States)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-12-01

    Warm forming operations have shown promise in expanding automotive heat exchanger designs by increasing forming limits of clad brazing sheet. The impact of isothermal holds below the clad melting temperature on subsequent brazeability has not previously been studied in detail. The effect of these holds on brazeability, as measured by the clad thickness loss due to solid state diffusion of Si out of the clad layer prior to clad melting, was assessed through parallel DSC and optical microscopy measurements, as well as through the use of a previously developed model. EPMA measurements were also performed to support the other measures. Overall, the same trends were predicted by DSC, microscopy, and the theoretical model; however, the DSC predictions were unable to accurately predict remaining clad thickness prior to melting, even after correcting the data for clad-core interactions. Microscopy measurements showed very good agreement with the model predictions, although there were slight discrepancies at short hold times due to the inability of the model to account for clad loss during heating to the brazing temperature. Further microscopy measurements showed that when the heating rate is set below a critical value, there is a reduction in the clad thickness from the as-received condition.

  4. Birefringence analysis of segmented cladding fiber.

    Science.gov (United States)

    Kumar, Ajeet; Rastogi, Vipul; Agrawal, Arti; Rahman, B M A

    2012-05-20

    We present a full-vectorial modal analysis of a segmented cladding fiber (SCF). The analysis is based on the H-field vectorial finite element method (VFEM) employing polar mesh geometry. Using this method, we have analyzed the circular SCF and the elliptical SCF. We have found that the birefringence of the circular SCF is very small (1.0×10(-8)). Birefringence of a highly elliptical SCF can be altered to some extent by the number of segments and duty cycle of segmentation in the segmented cladding. However, the change is not profound. The analysis shows that the circular SCF possesses low birefringence and that the segmented cladding does not add any significant birefringence in an elliptical fiber. This result strongly indicates that small deviations in the segmented cladding parameters arising from fabrication process do not significantly affect the birefringence of the fiber.

  5. Plasmonic waveguides cladded by hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Ishii, Satoshi; Shalaginov, Mikhail Y.; Babicheva, Viktoriia E.;

    2014-01-01

    Strongly anisotropic media with hyperbolic dispersion can be used for claddings of plasmonic waveguides (PWs). In order to analyze the fundamental properties of such waveguides, we analytically study 1D waveguides arranged from a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure....... We show that HMM claddings give flexibility in designing the properties of HIH waveguides. Our comparative study on 1D PWs reveals that HIH-type waveguides can have a higher performance than MIM or IMI waveguides....

  6. Optimization of metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, N.; Horvath, R.; Pedersen, H.C.

    2005-01-01

    The present paper deals with the optimization of metal-clad waveguides for sensor applications to achieve high sensitivity for adlayer and refractive index measurements. By using the Fresnel reflection coefficients both the angular shift and the width of the resonances in the sensorgrams are taken...... into account. Our optimization shows that it is possible for metal-clad waveguides to achieve a sensitivity improvement of 600% compared to surface-plasmon-resonance sensors....

  7. Flat-Cladding Fiber Bragg Grating Sensors for Large Strain Amplitude Fatigue Tests

    Directory of Open Access Journals (Sweden)

    Xijia Gu

    2010-08-01

    Full Text Available We have successfully developed a flat-cladding fiber Bragg grating sensor for large cyclic strain amplitude tests of up to ±8,000 με. The increased contact area between the flat-cladding fiber and substrate, together with the application of a new bonding process, has significantly increased the bonding strength. In the push-pull fatigue tests of an aluminum alloy, the plastic strain amplitudes measured by three optical fiber sensors differ only by 0.43% at a cyclic strain amplitude of ±7,000 με and 1.9% at a cyclic strain amplitude of ±8,000 με. We also applied the sensor on an extruded magnesium alloy for evaluating the peculiar asymmetric hysteresis loops. The results obtained were in good agreement with those measured from the extensometer, a further validation of the sensor.

  8. Development of a metal-clad advanced composite shear web design concept

    Science.gov (United States)

    Laakso, J. H.

    1974-01-01

    An advanced composite web concept was developed for potential application to the Space Shuttle Orbiter main engine thrust structure. The program consisted of design synthesis, analysis, detail design, element testing, and large scale component testing. A concept was sought that offered significant weight saving by the use of Boron/Epoxy (B/E) reinforced titanium plate structure. The desired concept was one that was practical and that utilized metal to efficiently improve structural reliability. The resulting development of a unique titanium-clad B/E shear web design concept is described. Three large scale components were fabricated and tested to demonstrate the performance of the concept: a titanium-clad plus or minus 45 deg B/E web laminate stiffened with vertical B/E reinforced aluminum stiffeners.

  9. Aluminum alloy

    Science.gov (United States)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  10. Fabrication and Lasing Property of Yb~(3+)-doped Double-Clad Fibers with Novel Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Yb3+-doped double-clad fibers with novel inner cladding have been made by using MCVD process, solution-doping method and optical machining together. The laser power and slope efficiency of the fiber lasers are higher than 1.8W and 50% respectively.

  11. Characterisation of a natural quartz crystal as a reference material for microanalytical determination of Ti, Al, Li, Fe, Mn, Ga and Ge

    Science.gov (United States)

    Audetat, Andreas; Garbe-Schonberg, Dieter; Kronz, Andreas; Pettke, Thomas; Rusk, Brian G.; Donovan, John J.; Lowers, Heather

    2015-01-01

    A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium-in-quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g-1), Al (154 ± 15 μg g-1), Li (30 ± 2 μg g-1), Fe (2.2 ± 0.3 μg g-1), Mn (0.34 ± 0.04 μg g-1), Ge (1.7 ± 0.2 μg g-1) and Ga (0.020 ± 0.002 μg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.

  12. Coarsening kinetics, thermodynamic properties, and interfacial characteristics of δ' precipitates in Al-Li alloys taking into account the Gibbs-Thomson effect

    Science.gov (United States)

    Tsao, C.-S.; Chen, C.-Y.; Huang, J.-Y.

    2004-11-01

    The structure factor model of small-angle x-ray scattering (SAXS) analysis is validated herein by transmission electron microscopy (TEM) result regarding the volume fraction and size of δ' precipitates. The kinetic behaviors of the number density and volume fraction of δ' precipitates in Al-Li alloys during the coarsening stage are quantitatively investigated by SAXS. The results indicate that the conventional kinetic law must be replaced by a more general equation that incorporates the Gibbs-Thomson effect and the time-dependence of the volume fraction during Ostwald ripening. This work also proposes new methods that combine the Gibbs-Thomson effect and the traditional SAXS equation to resolve more reliably and model independently the interfacial energy, the concentration of solute Li in the α matrix in equilibrium with δ' particles of a nanoscale radius Cαr , the equilibrium solubility of the α phase Ceα and the equilibrium concentration of δ' particles. The Gibbs-Thomson effect considers the effects of the interfacial energy and particle size on the equilibrium concentration. This effect quantitatively clarifies that the Cαr value is size-dependent and is related to the Ceα value and the interfacial energy. The traditional SAXS equation determines the Li concentrations in the δ' particles and the matrix from the measured scattering contrast. The traditionally determined solubility is in fact the Cαr value and is mistakenly regarded as the equilibrium concentration Ceα (corresponding to the radius is infinite). These results are compared to other results obtained by SAXS, TEM, and calculation. The time evolution of the transition interfacial layers between δ' particles and the matrix is extensively investigated using SAXS.

  13. The Enhanced Effect of Optical Emission from Laser Induced Breakdown Spectroscopy of an Al-Li Alloy in the Presence of Magnetic Field Confinement

    Science.gov (United States)

    Liu, Ping; Hai, Ran; Wu, Ding; Xiao, Qingmei; Sun, Liying; Ding, Hongbin

    2015-08-01

    In this paper, the influence of magnetic field strength on laser-induced breakdown spectroscopy (LIBS) has been investigated for various pressures. The plasma plume was produced by employing Q-switch Nd:YAG laser ablation of an Al-Li alloy operating at a 1064 nm wavelength. The results indicated that the LIBS intensity of the Al and Li emission lines is boosted with an increase of magnetic strength. Typically, the intensity of the Al I and Li I spectral emissions can be magnified by 1.5-3 times in a steady magnetic field of 1.1 T compared with the field-free case. Also, in this investigation we recorded time-resolved images of the laser-produced plume by employing a fast ICCD camera. The results show that the luminance of the plasma is enhanced and the time of persistence is increased significantly, and the plasma plume splits into two lobes in the presence of a magnetic field. The probable reason for the enhancement is the magnetic confinement effect which increases the number density of excited atoms and the population of species in a high energy state. In addition, the electron temperature and density are also augmented by the magnetic field compared to the field-free case. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2013GB109005) and National Natural Science Foundation of China (No. 11175035), Chinesisch-Deutsches Forschungs Project (GZ768), the Fundamental Research Funds for the Central Universities, China (Nos. DUT12ZD(G)01, (DUT14ZD(G)04), MMLab Research Project (DP1051208)

  14. Analyses of cladding modes in photonic crystal fiber.

    Science.gov (United States)

    Park, Hyun Chul; Hwang, In Kag; Yeom, Dong Il; Kim, Byoung Yoon

    2007-11-12

    Characteristics of cladding modes in a photonic crystal fiber (PCF) are numerically analyzed using the plane wave expansion method. The presence of the outer silica ring in the PCF tends to push the optical fields of the cladding modes toward the rim of the PCF, which creates 'ring modes' whose fields are tightly confined in the outer ring. The dispersion of the cladding modes are determined mainly by the dispersive property of the holey cladding structure. The optical field patterns of the cladding modes and the beatlengths between the fundamental mode and the cladding modes are also investigated.

  15. In-situ laser material process monitoring using a cladding power detection technique

    Science.gov (United States)

    Su, Daoning; Norris, Ian; Peters, Chris; Hall, Denis R.; Jones, Julian D. C.

    Progress in laser material processing may require real-time monitoring and process control for consistent quality and productivity. We report a method of in-situ monitoring of laser metal cutting and drilling using cladding power monitoring of an optical fibre beam delivery system—a technique which detects the light reflected or scattered from the workpiece. The light signal carries information about the quality of the process. Experiments involving drilling and cutting of two samples, a thin aluminum foil and a 2-mm thick stainless steel plate, confirmed the effectiveness of this method.

  16. Aluminum-lithium alloy development for thixoforming

    Energy Technology Data Exchange (ETDEWEB)

    Sauermann, R.; Friedrich, B. [IME Process Metallurgy and Metal Recycling, RWTH Aachen Univ. (Germany); Puettgen, W.; Bleck, W. [IEHK Inst. for Ferrous Metallurgy, RWTH Aachen Univ. (Germany); Balitchev, E.; Hallstedt, B.; Schneider, J.M. [MCh Materials Chemistry, RWTH Aachen Univ. (Germany); Bramann, H.; Buehrig-Polaczek, A. [GI Foundry Inst., RWTH Aachen Univ. (Germany); Uggowitzer, P.J. [ETH Zuerich, Metal Physics and Technology (Germany)

    2004-12-01

    This paper presents a scientific contribution to the development of lightweight/high-performance Al-Li alloys suitable for semi-solid processing. Thermodynamic calculations identified the most promising compositions with focus on the solidus-liquidus interval, fraction of solid-versus-temperature and phase reactions. The synthesis of Al-Li precursor billets was performed by overpressure induction melting in controlled atmosphere. DTA and microstructure investigations on Al-Li specimens were carried out as well as thixocasting trials of demonstrator components. New rheocasting of Al-Li alloys was investigated to identify the potential of this alternative precursor material route. It is shown that specifically developed Al-Li alloys offer great potential for semi-solid manufacturing. (orig.)

  17. Multilayer cladding with hyperbolic dispersion for plasmonic waveguides

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    We study the properties of plasmonic waveguides with a dielectric core and multilayer metal-dielectric claddings that possess hyperbolic dispersion. The waveguides hyperbolic multilayer claddings show better performance in comparison to conventional plasmonic waveguides. © OSA 2015....

  18. The Absorption Characteristics of Inhomogeneous Double-Clad Fibers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The absorption characteristics of radially inhomogeneous double-clad fiber (DCF) are investigated firstly with the method of caustic radius, combined with the method of WKBJ. The results are significant for double-clad optical fiber lasers and amplifiers.

  19. Capturing reflected cladding modes from a fiber Bragg grating with a double-clad fiber coupler.

    Science.gov (United States)

    Baiad, Mohamad Diaa; Gagné, Mathieu; Lemire-Renaud, Simon; De Montigny, Etienne; Madore, Wendy-Julie; Godbout, Nicolas; Boudoux, Caroline; Kashyap, Raman

    2013-03-25

    We present a novel measurement scheme using a double-clad fiber coupler (DCFC) and a fiber Bragg grating (FBG) to resolve cladding modes. Direct measurement of the optical spectra and power in the cladding modes is obtained through the use of a specially designed DCFC spliced to a highly reflective FBG written into slightly etched standard photosensitive single mode fiber to match the inner cladding diameter of the DCFC. The DCFC is made by tapering and fusing two double-clad fibers (DCF) together. The device is capable of capturing backward propagating low and high order cladding modes simply and efficiently. Also, we demonstrate the capability of such a device to measure the surrounding refractive index (SRI) with an extremely high sensitivity of 69.769 ± 0.035 μW/RIU and a resolution of 1.433 × 10(-5) ± 8 × 10(-9) RIU between 1.37 and 1.45 RIU. The device provides a large SRI operating range from 1.30 to 1.45 RIU with sufficient discrimination for all individual captured cladding modes. The proposed scheme can be adapted to many different types of bend, temperature, refractive index and other evanescent wave based sensors.

  20. Laser powder technology for cladding and welding

    Science.gov (United States)

    Arnold, J.; Volz, R.

    1999-06-01

    Laser powder technology offers several advantages compared to conventional cladding and welding techniques and is attracting increasing industrial interest. The laser materials processing group of the German Aerospace Center at Stuttgart, Germany, is currently developing these new methods for application in industrial process engineering. Key areas of the work include the design and implementation of a modular working head that can be universally used for laser welding and surface treatment, the development of powder nozzles for cladding and welding, and the construction of new systems for special applications (e.g., for inner cladding). Some of these developments are described, as well as some important examples that highlight the potential of welding and surface treatment using laser powder techniques.

  1. Mechanical modelling of transient- to- failure SFR fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Feria, F.; Herranz, L. E.

    2014-07-01

    The response of Sodium Fast Reactor (SFR) fuel rods to transient accident conditions is an important safety concern. During transients the cladding strain caused by the stress due to pellet cladding mechanical interaction (PCMI) can lead to failure. Due to the fact that SFR fuel rods are commonly clad with strengthened material made of stainless steel (SS), cladding is usually treated as an elastic-perfectly-plastic material. However, viscoplastic behaviour can contribute to mechanical strain at high temperature (> 1000 K). (Author)

  2. Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

    Science.gov (United States)

    Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

    2014-04-07

    We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

  3. Spatial Mode Selective Waveguide with Hyperbolic Cladding

    CERN Document Server

    Tang, Y; Xu, M; Bäumer, S; Adam, A J L; Urbach, H P

    2016-01-01

    Hyperbolic Meta-Materials~(HMMs) are anisotropic materials with permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as cladding material, a waveguide which only supports higher order modes can be achieved, while the lower order modes become leaky and are absorbed in the HMM cladding. This counter intuitive property can lead to novel application in optical communication and photonic integrated circuit. The loss in our HMM-Insulator-HMM~(HIH) waveguide is smaller than that of similar guided mode in a Metal-Insulator-Metal~(MIM) waveguide.

  4. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence...

  5. Analysis of failures of waterproofing cladding layers of terracotta tiles

    Directory of Open Access Journals (Sweden)

    Koláčný Milan

    2017-01-01

    Full Text Available The article is focused on one of the most important roof cladding layers – the waterproofing cladding layer of terracotta tiles. Its detailed analysis covers the main waterproofing cladding layers in terms of their material characteristics and installation methods. The article concludes by formulating principles for the correct design of the main waterproofing layer/construction.

  6. yb3+-Doped Double-Clad Fibre Laser Pumped by Rectangular Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    宁鼎; 李乙刚; 黄榜才; 孙建军; 吕可诚; 袁树忠; 董孝义

    2001-01-01

    A novel Yb3+-doped double-clad silica fibre with rectangular inner cladding was designed and developed by using the modified chemical vapour deposition process, solution-doping and optical machining all together. The dimensions of the inner cladding are 100 × 70 μm, and Yb3+-doped concentration in the core is about 0.24 wt. %. The operation of the fibre laser pumped by inner cladding is reported. The threshold of the laser is 34mW.When the pump power launched is 141mW, the laser output is 84mW at the wavelength 1075.6nm, and the slope efficiency is 77%.

  7. Functionally graded materials with laser cladding

    NARCIS (Netherlands)

    de Hosson, J.T.M.; Pei, Y.T.; Brebbia, CA

    2001-01-01

    Al-40 w/o Si functionally graded materials (FGMs) were produced by a onestep laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surro

  8. Functionally graded materials produced by laser cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  9. Functionally Graded Materials Produced by Laser Cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  10. Analysis of coaxial laser cladding processing conditions

    NARCIS (Netherlands)

    de Oliveira, U; Ocelik, V; De Hosson, JTM

    2005-01-01

    The formation of thick Ni-based coating on a steel substrate by coaxial laser cladding using the Nd:YAG 2 kW continuous laser was studied both from a theoretical and experimental point of view. The theoretical analysis concentrated on the transfer of laser irradiation and powder particles using a si

  11. CLAD CARBIDE NUCLEAR FUEL, THERMIONIC POWER, MODULES.

    Science.gov (United States)

    The general objective is to evaluate a clad carbide emitter, thermionic power module which simulates nuclear reactor installation, design, and...performance. The module is an assembly of two series-connected converters with a single common cesium reservoir. The program goal is 500 hours

  12. Thick tool steel coatings with laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; de Oliveira, U.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2007-01-01

    This paper concentrates on thick and crack-free laser clad coatings (up to 3 mm). The coating material is a chromium-molybdenum-tungsten-vanadium alloyed high-speed steel that shows high wear resistance, high compressive strength, good toughness, very good dimensional stability on heat treatment and

  13. PFR fuel cladding transient test results and analysis

    Science.gov (United States)

    Cannon, N. S.; Hunter, C. W.; Kear, K. L.; Wood, M. H.

    1986-05-01

    Fuel Cladding Transient Tests (FCTT) were performed on M316 cladding specimens obtained from mixed-oxide fuel pins irradiated in the Prototype Fast Reactor (PFR) to burnups of 4 and 9 atom percent. In these tests, specimens of fuel cladding were pressurized and heated until failure occurred. Samples of cladding from PFR fuel pins exhibited generally greater strength and ductility than specimens from Experimental Breeder Reactor-II (EBR-II) mixed-oxide fuel pins tested under similar conditions. Apparently, the PFR cladding properties were not degraded by a fuel adjacency effect (FAE) observed in fuel pin cladding from EBR-II irradiations. A recently developed model of grain boundary cavity growth was used to predict the results of the tests conducted on PFR cladding. It was found that the predicted failure temperatures for the relevant internal pressures were in good agreement with experimental failure temperatures.

  14. Temperature and stress fields of multi-track laser cladding

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-yun; ZHANG nong-tao; XU Chun-hua; YANG Xian-qun

    2009-01-01

    Based on genetic algorithm and neural network algorithm, the finite element analyses on the temperature fields and stress fields of multi-track laser cladding were carried out by using the ANSYS software. The results show that, in the multi-track cladding process, the temperature field ellipse leans to the cladding formed, and the front cladding has preheating function on the following cladding. During cladding, the longitudinal stress is the largest, the lateral stress is the second, and the thickness direction stress is the smallest. The center of the cladding is in the tensile stress condition. The longitudinal tensile stress is higher than the lateral or thickness direction stress by several times, and the tensile stress achieves the maximum at the area of joint between the cladding and substrate. Therefore, it is inferred that transversal crack is the most main crack form in multi-track laser cladding. Moreover, the joint between cladding and substrate is the crack sensitive area, and this is consistent with the actual experiments.

  15. Suppression of transverse-mode spurious responses for SAW resonators on SiO2/Al/LiNbO3 structure by selective removal of SiO2.

    Science.gov (United States)

    Nakamura, Hiroyuki; Nakanishi, Hidekazu; Goto, Rei; Hashimoto, Ken-ya

    2011-10-01

    A SiO(2)/Al/LiNbO(3) structure has a large electromechanical coupling factor (K(2)) and good temperature coefficient of frequency (TCF) for applications as a SAW duplexer of the Universal Mobile Telecommunications System (UMTS) Band I. However, the SiO(2)/Al/LiNbO(3) structure also supports two unwanted spurious responses; one is caused by the Rayleigh mode and the other by the transverse mode. As the authors have previously discussed, the Rayleigh-mode spurious response can be suppressed by controlling the cross-sectional shape of a SiO(2) overlay deposited on resonator electrodes. In this paper, a new technique to suppress the transverse-mode spurious responses is proposed. In the technique, the SiO(2) overlay is selectively removed from the dummy electrode region. The spurious responses are analyzed by the laser probe system. The results indicate that the spurious responses in question were hybrid modes caused by the coupling between the main (SH) SAW and another (Rayleigh) SAW with different velocities. The hybrid-mode spurious behavior was dependent on the velocities in the IDT and the dummy regions (v(i) and v(d)). The hybrid-mode spurious responses could be suppressed by selectively removing SiO(2). Furthermore, the SAW energy confinement could be enhanced in the IDT electrode region when v(i) < v(d). The transverse-mode spurious responses were successfully suppressed without degrading the SAW resonator performances.

  16. Impact of reactor water chemistry on cladding performance

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B. [University of Toronto, Centre for Nuclear Engineering, Toronto, Ontario (Canada)

    1997-07-01

    Water chemistry may have a major impact on fuel cladding performance in PWRs. If the saturation temperature on the surface of fuel cladding is exceeded, either because of the thermal hydraulics of the system, or because of crud deposition, then LiOH concentration can occur within thick porous oxide films on the cladding. This can degrade the protective film and accelerate the corrosion rate of the cladding. If sufficient boric acid is also present in the coolant then these effects may be mitigated. This is normally the case through most of any reactor fuel cycle. Extensive surface boiling may disrupt this equilibrium because of the volatility of boric acid in steam. Under such conditions severe cladding corrosion can ensue. The potential for such effects on high burnup cladding in CANDU reactors, where bone acid is not present in the primary coolant, is discussed. (author)

  17. Cladded single crystal fibers for high power fiber lasers

    Science.gov (United States)

    Kim, W.; Shaw, B.; Bayya, S.; Askins, C.; Peele, J.; Rhonehouse, D.; Meyers, J.; Thapa, R.; Gibson, D.; Sanghera, J.

    2016-09-01

    We report on the recent progress in the development of cladded single crystal fibers for high power single frequency lasers. Various rare earth doped single crystal YAG fibers with diameters down to 17 μm with length > 1 m have been successfully drawn using a state-of-the-art Laser Heated Pedestal Growth system. Single and double cladding on rare earth doped YAG fibers have been developed using glasses where optical and physical properties were precisely matched to doped YAG core single crystal fiber. The double clad Yb:YAG fiber structures have dimensions analogous to large mode area (LMA) silica fiber. We also report successful fabrications of all crystalline core/clad fibers where thermal and optical properties are superior over glass cladded YAG fibers. Various fabrication methods, optical characterization and gain measurements on these cladded YAG fibers are reported.

  18. Investigation of the Precipitation Behavior in Aluminum Based Alloys

    KAUST Repository

    Khushaim, Muna S.

    2015-11-30

    The transportation industries are constantly striving to achieve minimum weight to cut fuel consumption and improve overall performance. Different innovative design strategies have been placed and directed toward weight saving combined with good mechanical behavior. Among different materials, aluminum-based alloys play a key role in modern engineering and are widely used in construction components because of their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. For intelligent microstructure design in the complex Al-based alloy, it is important to gain a deep physical understanding of the correlation between the microstructure and macroscopic properties, and thus atom probe tomography with its exceptional capabilities of spatially resolution and quantitative chemical analyses is presented as a sophisticated analytical tool to elucidate the underlying process of precipitation phenomena in aluminum alloys. A complete study examining the influence of common industrial heat treatment on the precipitation kinetics and phase transformations of complex aluminum alloy is performed. The qualitative evaluation results of the precipitation kinetics and phase transformation as functions of the heat treatment conditions are translated to engineer a complex aluminum alloy. The study demonstrates the ability to construct a robust microstructure with an excellent hardness behavior by applying a low-energy-consumption, cost-effective method. The proposed strategy to engineer complex aluminum alloys is based on both mechanical strategy and intelligent microstructural design. An intelligent microstructural design requires an investigation of the different strengthen phases, such as T1 (Al2CuLi), θ′(Al2Cu), β′(Al3Zr) and δ′(Al3Li). Therefore, the early stage of phase decomposition is examined in different binary Al-Li and Al-Cu alloys together with different

  19. Clad fiber capacitor and method of making same

    Science.gov (United States)

    Tuncer, Enis

    2012-12-11

    A clad capacitor and method of manufacture includes assembling a preform comprising a ductile, electrically conductive fiber; a ductile, electrically insulating cladding positioned on the fiber; and a ductile, electrically conductive sleeve positioned over the cladding. One or more preforms are then bundled, heated and drawn along a longitudinal axis to decrease the diameter of the ductile components of the preform and fuse the preform into a unitized strand.

  20. Pellet-clad interaction in water reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The aim of this seminar is was to draw up a comprehensive picture of the pellet clad interaction and its impact on the fuel rod. This document is a detailed abstract of the papers presented during the following five sessions: industrial goals, fuel material behaviour in PCI situation, cladding behaviour relevant to PCI, in pile rod behaviour and modelling of the mechanical interaction between pellet and cladding. (A.L.B.)

  1. Water-moderated reactor fuel cladding reliability study

    OpenAIRE

    Бакутяк, Елена Викторовна; Пелых, Сергей Николаевич

    2014-01-01

    Considering the fuel element, averaged by fuel assembly (FA) of water-moderated reactor with the power of 1000 MW (VVER-1000), the number of fuel elements with the greatest cladding failure probability after 4 operation years at Khmelnitsky NPP-2 (KNPP-2) is found. This will allow to calculate the fuel cladding failure probability and determine the most likely cladding damages, which will enable to improve the performance and economic indexes of VVER.The novelty of the paper lies in calculati...

  2. Annular-cladding erbium doped multicore fiber for SDM amplification.

    Science.gov (United States)

    Jin, Cang; Ung, Bora; Messaddeq, Younès; LaRochelle, Sophie

    2015-11-16

    We propose and numerically investigate annular-cladding erbium doped multicore fibers (AC-EDMCF) with either solid or air hole inner cladding to enhance the pump power efficiency in optical amplifiers for spatial division multiplexing (SDM) transmission links. We first propose an all-glass fiber in which a central inner cladding region with a depressed refractive index is introduced to confine the pump inside a ring-shaped region overlapping the multiple signal cores. Through numerical simulations, we determine signal core and annular pump cladding parameters respecting fabrication constraints. We also propose and examine a multi-spot injection scheme for launching the pump in the annular cladding. With this all-glass fiber with annular cladding, our results predict 10 dB increase in gain and 21% pump power savings compared to the standard double cladding design. We also investigate a fiber with an air hole inner cladding to further enhance the pump power confinement and minimize power leaking into the inner cladding. The results are compared to the all-glass AC-EDMCF.

  3. Nuclear reactor fuel element with vanadium getter on cladding

    Science.gov (United States)

    Johnson, Carl E.; Carroll, Kenneth G.

    1977-01-01

    A nuclear reactor fuel element is described which has an outer cladding, a central core of fissionable or mixed fissionable and fertile fuel material and a layer of vanadium as an oxygen getter on the inner surface of the cladding. The vanadium reacts with oxygen released by the fissionable material during irradiation of the core to prevent the oxygen from reacting with and corroding the cladding. Also described is a method for coating the inner surface of small diameter tubes of cladding with a layer of vanadium.

  4. Second harmonic generation in thin optical fibers via cladding modes.

    Science.gov (United States)

    Elzahaby, Eman A; Kandas, Ishac; Aly, Moustafa H

    2016-05-30

    Since silica goes under the category of amorphous materials, it is difficult to investigate important processes such as second harmonic generation (SHG) in silica-based fibers. In this paper, we proposed a method for SHG relaying on cladding modes as pump modes. Cladding modes are introduced in optical fibers through tilted long period grating (T-LPG), where power of core mode is transferred into cladding modes. By functionalizing T-LPG with nonlinear coating, the interaction occurs between cladding modes and the coating material, consequently second harmonic signal (SHS) is generated with efficiency up to 0.14%.

  5. Finite-width plasmonic waveguides with hyperbolic multilayer cladding.

    Science.gov (United States)

    Babicheva, Viktoriia E; Shalaginov, Mikhail Y; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2015-04-20

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

  6. Hollow core anti-resonant fibres with split cladding

    Science.gov (United States)

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Luan, Feng; Yong, Ken-Tye; Yoo, Seongwoo

    2016-03-01

    A split cladding fibers (SCF) is proposed as an additional design to the anti-resonant type fiber. The introduced split cladding helps to reduce the fabrication distortion. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF. Fabrication of the SCF is demonstrated by the stack-and-draw technique. The near filed mode patterns are measured to prove the feasibility of this fiber design.

  7. Microstructural Characterization of Cermet Cladding Developed Through Microwave Irradiation

    Science.gov (United States)

    Gupta, Dheeraj; Sharma, Apurbba Kumar

    2012-10-01

    In the present work, cladding of hardfacing WC10Co2Ni powder on austenitic stainless steel has been developed through a novel processing technique. The clads were developed using microwave hybrid heating. The clad of average thickness ~2 mm has been developed through the exposure of microwave radiation at frequency 2.45 GHz and power 900 W for the duration of 360 s. The developed clads were characterized using field emission scanning electron microscope, X-ray elemental analysis, X-ray diffraction, and measurement of Vicker's microhardness. The microstructure study of the clad showed good metallurgical bonding with substrate and revealed that clads are free from any visible interface cracking. Clads were formed with partial dilution of a thin layer of the substrate. The cermet microstructure mainly consists of relatively soft metallic matrix phase and uniformly distributed hard carbide phase with skeleton-like structure. The developed clads exhibit an average microhardness of 1064 ± 99 Hv. The porosity of developed clad has been significantly less at approximately 0.89%.

  8. Clad strip casting by a twin roll caster

    OpenAIRE

    T. Haga; Nakamura, R; S. Kumai; H. Watari

    2009-01-01

    Purpose: Of this paper is to realize the casting of the clad strip by only one process. Therefore, the investigation of the ability of the casting of the clad strip by a vertical type twin roll caster was operated. The aim of the use of the twin roll caster to make clad strip was in the reduction of the production-energy of the clad strip.Design/methodology/approach: Used in the present study was a vertical type twin roll caster with the scriber. The scriber was used to prevent the mixture of...

  9. Design and fabrication of triangular inner cladding double-clad ytterbium doped fibre for high power lasers

    Institute of Scientific and Technical Information of China (English)

    Fu Yong-Jun; Jian Wei; Zheng Kai; Yan Feng-Ping; Chang De-Yuan; Jian Shui-Sheng

    2005-01-01

    To improve the performance of double clad high power fibre lasers, inner cladding design plays a significant role.A triangular inner cladding and silica structure second cladding with large air holes to acquire high inner cladding numerical aperture are designed. Single mode and high power output of the fibre lasers need the double clad Yb doped fibre with large core. A fibre with annular refractive index distribution core and low numerical aperture to acquire a large mode area fibre core is designed and fabricated. Furthermore co-doping with aluminium (Al) has been used to improve the solubility of ytterbium (Yb) into silicate network, and the core absorption coefficients of two Yb doped fibres are compared with different Al concentration experimentally.

  10. Suppression of Cladding Mode Coupling by B/Ge Codoped Photosensitive Fiber With Photosensitive and Depressed Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Excess loss on the short wavelength side of the Bragg resonant wavelength caused by cladding mode coupling limits wide use of grating in the fiber communication system, especially in densed wavelength division multiplexing (DWDM) system.A novel photosensitive fiber design that have depressed cladding and photosensitive inner cladding in the same fiber is proposed, which can suppress cladding mode coupling greatly.Using MCVD method B/Ge codoped fiber with depressed cladding was fabriceted out, which was also doped in boron and germanium and had the photosensitivity.Finally, the transmission spectrum of written grating in this fiber by phase mask method verified its larger photosensitivity and greatly suppression of cladding mode coupling.

  11. Thermomechanical loading applied on the cladding tube during the pellet cladding mechanical interaction phase of a rapid reactivity initiated accident

    OpenAIRE

    2014-01-01

    International audience; Calculations of the CABRI REP-Na5 pulse were performed with the ALCYONE code in order to determine the evolution of the thermomechanical loading applied on the cladding tube during the Pellet-Cladding Mechanical Interaction (PCMI) phase of a rapid Reactivity Initiated Accident (RIA) initiated at 280 °C that lasted 8.8 ms. The evolution of the following parameters are reported: the cladding temperature, heating rate, strain rate and loading biaxiality. The impact of the...

  12. Design of Matched Cladding Fiber with UV-sensitive Cladding for Minimization of Claddingmode Losses in Fiber Bragg Gratings

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Berendt, Martin Ole; Bjarklev, Anders Overgaard;

    2000-01-01

    The effect on the Bragg-grating-induced cladding-mode coupling of varying the extent of the photosensitive region in a step-index fiber is analyzed. We introduce a figure of merit for the suppression of cladding-mode loss and compare different matched cladding fiber designs. It is found...... to be advantageous to increase the extent of the photosensitive region. However, no significant improvement is obtained by extending the photosensitive region more than approximately 10 mu m into the cladding. This result is not in agreement with a simple analysis that neglects UV absorption, which suggests...

  13. Thermomechanical loading applied on the cladding tube during the pellet cladding mechanical interaction phase of a rapid reactivity initiated accident

    Science.gov (United States)

    Hellouin de Menibus, Arthur; Sercombe, Jerome; Auzoux, Quentin; Poussard, Christophe

    2014-10-01

    Calculations of the CABRI REP-Na5 pulse were performed with the ALCYONE code in order to determine the evolution of the thermomechanical loading applied on the cladding tube during the Pellet-Cladding Mechanical Interaction (PCMI) phase of a rapid Reactivity Initiated Accident (RIA) initiated at 280 °C that lasted 8.8 ms. The evolution of the following parameters are reported: the cladding temperature, heating rate, strain rate and loading biaxiality. The impact of these parameters on the cladding mechanical behavior and fracture are then briefly reviewed.

  14. Study of the effects of surface cladding on 3D transmon

    Science.gov (United States)

    Yoscovits, Zachary Robert

    Quantum computing is a very interesting field, due to the ability of quantum computers to solve many problems much faster than a classical computer. Superconducting qubits are electronic circuits composed of superconducting capacitors, inductors and Josephson junctions, which can implement a physical qubit. However they need improvements in their coherence time to create a viable quantum computing. In this work I study the effect on decoherence caused by two level systems in the native oxide that forms on the surface of qubit. To this end I fabricate 3D transmon qubits using materials grown my molecular beam epitaxy, to which a variety of different surface treatments had been applied. I began by fabricating qubits from niobium/aluminum oxide/niobium trilayers. To this end I developed a self-aligned process for fabricating sub-micron Josephson junctions. This process presented many challenges. During the development of this process, it became clear that niobium was an inferior material for fabricating qubits compared to aluminum. I then switched to making qubits from Aluminum. I began by studying the growth of aluminum on sapphire, and was able to achieve aluminum films with an RMS roughness of 0.2 nm by growing on c-plane sapphire that had been annealed in oxygen at 1100 °C and dipped in BOE. Next I fabricated 3D transmon qubits by adapting the standard shadowmask process for use with MBE. I fabricated qubits with a long in situ oxidation to fully passivate the surface before exposure to air. I also passivated the surface by means of growing co deposited aluminum oxide, and by grown aluminum nitride using a nitrogen plasma source. The coherence times of these qubits were compared to those a control sample that had been exposed to air immediately after growth. Overall it doesn't appear that cladding the surface changes the coherence time much, however it is difficult to form conclusions with this small sample size. The coated samples appeared to have slightly

  15. Metallographic Analyses of Laser Cladded WC-Ni and WC-Co Hard-facing Metals

    Institute of Scientific and Technical Information of China (English)

    HK Chikwanda; M Chiremba; C Van Rooyen

    2004-01-01

    Laser cladding is performed to improve the surface properties of metallic machine components. Extensive work is being conducted to investigate the relationships among the cladding parameters, clad powder characteristics and the quality of the clad layer. This work presents some of the metallographic analyses results of WC -Ni and WC-Co clad layers. The clad layers are characterised with non-uniform carbide particles, mostly WC imbedded in a more ductile matrix.The transition from the clad layer to the substrate metal had a distinct dilution zone. The ratio of this zone to the clad height was in the range of 10 -12% and this still needs to be refined.

  16. Photonic lantern with cladding-removable fibers

    Science.gov (United States)

    Sun, Weimin; Yan, Qi; Bi, Yao; Yu, Haijiao; Liu, Xiaoqi; Xue, Jiuling; Tian, He; Liu, Yongjun

    2014-07-01

    Recently, spectral measurement becomes an important tool in astronomy to find exoplanets etc. The fibers are used to transfer light from the focal plate to spectrometers. To get high-resolution spectrum, the input slits of the spectrometers should be as narrow as possible. In opposite, the light spots from the fibers are circle, which diameters are clearly wider than the width of the spectrometer slits. To reduce the energy loss of the fiber-guide star light, many kinds of image slicers were designed and fabricated to transform light spot from circle to linear. Some different setup of fiber slicers are introduced by different research groups around the world. The photonic lanterns are candidates of fiber slicers. Photonic lantern includes three parts: inserted fibers, preform or tubing, taped part of the preform or tubing. Usually the optical fields concentrate in the former-core area, so the light spots are not uniform from the tapered end of the lantern. We designed, fabricated and tested a special kind of photonic lantern. The special fibers consist polymer cladding and doped high-index core. The polymer cladding could be easily removed using acetone bath, while the fiber core remains in good condition. We inserted the pure high-index cores into a pure silica tubing and tapered it. During the tapering process, the gaps between the inserted fibers disappeared. Finally we can get a uniform tapered multimode fiber end. The simulation results show that the longer the taper is, the lower the loss is. The shape of the taper should be controlled carefully. A large-zone moving-flame taper machine was fabricated to make the special photonic lantern. Three samples of photonic lanterns were fabricated and tested. The lanterns with cladding-removable fibers guide light uniform in the tapered ends that means these lanterns could collect more light from those ends.

  17. Effect of the composition of Al-Li alloys on the quantitative relation between the δ'(Al3Li), S1(Al2MgLi), and T1(Al2CuLi) phases

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Grushin, I. A.; Knyazev, M. I.; Khokhlatova, L. B.; Alekseev, A. A.

    2015-01-01

    Al-Li alloys are considered. A quantitative approach to the determination of the ratio of the fractions of the binary and ternary intermetallic phases in Al-Mg(Cu)-Li alloys is developed on the basis of chemical and phase composition balance equations and the experimentally measured lattice parameter of the α solid solution. The ratio of the fractions of the δ'(Al3Li) and S1(T1) phases in Al-Mg(Cu)-Li alloys is shown to be determined by the ratio of the mole fractions of Li and Mg(Cu). Equations are proposed for calculating the weight fractions of the S1(Al2MgLi), T1(Al2CuLi) and δ'(Al3Li) phases in domestic and foreign Al-Mg-Li alloys 1420, 1424, 5090 and Al-Cu-Li alloys 1440, 1460, 1461, 1441, 1469, 2090, 2095, 8090, and Weldalite 049.

  18. Ferrous Alloy Powder for Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    WEN Jialing; NIU Quanfeng; XU Yanmin

    2005-01-01

    This investigation aimed at how to improve the hardness and wear resistance by B, Si and Cr, and how to improve the synthesis property by Re (rare-earth element). Based on the experiment of Fe-based alloys of Fe-Cr-Ni-B-Si-Re, through experiments and a serious of synthesis analysis, including surface quality, spectrum composite, micro-hardness, scanning electron microscopy, as well as the synthesis evaluation,etc, prescriptions were optimized. As a result, a Fe-Cr-Ni-B-Si-Re cladding material with a high property was obtained.

  19. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  20. Evolución de la fricción interna del material compuesto de matriz Al-Li 8090 reforzado con partículas de SiC

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Urrutia, I.

    2001-04-01

    Full Text Available The present study has been undertaken to investigate the mechanism of thermal stress relief at the range of temperatures below room temperature for the metal matrix composite Al-Li 8090/SiC. For this aim the experimental technique of internal friction has been used which has been showed up very effective. Several thermal cycles from 453 K to 100 K were used in order to measure the internal friction as well as the elastic modulus of the material concluding that thermal stresses are relaxed by microplastic deformation around the reinforcements. It has been also related the variation in the elastic modulus with the different levels of precipitation.

    El presente trabajo investiga el mecanismo de relajación de tensiones térmicas a temperaturas por debajo de la de ambiente en el material compuesto Al-Li 8090/SiC. Para ello se ha empleado la técnica experimental de fricción interna que se ha mostrado la más eficaz para tal fin. Aplicando diferentes ciclos térmicos de 453 K a 100 K se midió tanto la fricción interna como el módulo elástico del material concluyendo que el mecanismo de relajación de tensiones térmicas es el de microdeformación plástica alrededor del reforzamiento. También se relaciona la variación del módulo elástico con los diferentes estadios de precipitación.

  1. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Ocelik, V.; Pei, Y.T.; de Hosson, J.T.M.; Popoola, O; Dahotre, NB; Midea, SJ; Kopech, HM

    2003-01-01

    Two functionally graded coatings were prepared by different laser surface engineering techniques. Laser cladding of AlSi40 powder leads to the formation of functionally graded material (FGM) coating on AI-Si cast alloy substrate. Mapping of strain fields near the laser clad track using the digital i

  2. Cladding of Advanced Al Alloys Employing Friction Stir Welding

    NARCIS (Netherlands)

    Stelt, van der A.A.; Bor, T.C.; Geijselaers, H.J.M.; Akkerman, R.; Boogaard, van den A.H.

    2013-01-01

    In this paper an advanced solid state cladding process, based on Friction Stir Welding, is presented. The Friction Surface Cladding (FSC) technology enables the deposition of a solid-state coating using filler material on a substrate with good metallurgical bonding. A relatively soft AA1050 filler m

  3. Compact cladding-pumped planar waveguide amplifier and fabrication method

    Science.gov (United States)

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  4. Thermal shock in a circumferentially cracked hollow cylinder with cladding

    Science.gov (United States)

    Nied, H. F.

    1984-01-01

    An theoretical analysis is presented which demonstrates the effect of cladding on the thermal resistance of a circumferentially cracked hollow cylinder. The cladding is assumed to be bonded to the inner wall of the hollow cylinder. The axisymmetric circumferential crack may be either embedded in the cylinder wall or may be an edge crack which passes through the clad and opens into the inner wall of the hollow cylinder. The problem is formulated mathematically and a solution is found which is in the form of a single integral equation. The integral equation is solved numerically and yields estimates of transient temperature distributions, thermal stresses in the uncracked cylinder, and stress intensity factors as a function of time for various cladding thickness to cylinder wall thickness ratios. It is shown that yielding of the clad under certain conditions can result in a reduction in the magnitude of the stress intensity factor for the crack tip in the elastic base material.

  5. Reduction of Bragg-grating-induced coupling to cladding modes

    DEFF Research Database (Denmark)

    Berendt, Martin Ole; Bjarklev, Anders Overgaard; Soccolich, C.E.

    1999-01-01

    We discuss fiber designs that have been suggested for the reduction of Bragg-grating induced coupling to cladding modes. The discussion is based on a theoretical approach that includes the effect of asymmetry in the UV-induced index grating, made by UV-side writing. Experimental results from...... gratings in a depressed-cladding fiber are compared with simulations. The model gives good agreement with the measured transmission spectrum and accounts for the pronounced coupling to asymmetrical cladding modes, even when the grating is written with the smallest possible blaze. The asymmetry causing...... this is accounted for by the unavoidable attenuation of the UV light. It is found for the considered fiber designs that a high numerical-aperture fiber increases the spectral separation between the Bragg resonance and the onset of cladding-mode losses. A depressed-cladding fiber reduces the coupling strength...

  6. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogeniz......Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any...... homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence...

  7. Prediction of inhomogeneous texture in clad sheet metals by hot roll bond method

    Science.gov (United States)

    Choi, Shi-Hoon; Kwon, Jae Wook; Oh, Kyu Hwan

    1996-06-01

    A finite element analysis was applied to analyze the evolution of an inhomogeneity of rolling texture in hot rolled clad metal with Taylor-Bishop-Hill model and Renourd-Winterberger method. The shear texture has been developed in the surface layer of the aluminum and plane strain texture has been developed in the center layer. The calculated texture variations through thickness direction could simulate experimental texture using deformation gradient from FEM. The ratio of shear strain to rolling strain, x, which represents the degree of rotation about transverse direction could give the degree of development of shear texture. The larger value of x gives the larger crystal rotation about transverse direction and subsequently the development of shear texture. The calculated (111) pole figures were in good agreement with experimentally measured pole figures.

  8. Cladding embrittlement during postulated loss-of-coolant accidents.

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  9. Material Selection for Accident Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Snead, Lance Lewis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Alternative cladding materials to Zr-based alloys are being investigated for accident tolerance, which can be defined as > 100X improvement (compared to Zr-based alloys) in oxidation resistance to steam or steam-H2 environments at ≥ 1200°C for short times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. However, commercial Ti2AlC that was not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore Ti2AlC may be challenging to form as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation-assisted α´ formation. The composition effects and critical limits to retaining protective scale formation at > 1400°C are still being evaluated.

  10. Fabrication and Lasing Property of YbYb3+-doped Double-Clad Fibers with Novel Inner Cladding

    Institute of Scientific and Technical Information of China (English)

    Ding Ning; Yang Xiang; Zhaowen Xu; Wande Fan; Yongqing Yi; Shuzhong Yuan; Xiaoyi Dong

    2003-01-01

    The Yb3+-doped double-clad fibers with novel inner cladding have been made by using MCVD process, solution-doping method and optical machining together. The laser power and slope efficiency of the fiber lasers are higher than 1.8W and 50% respectively.

  11. Glass-clad semiconductor core optical fibers

    Science.gov (United States)

    Morris, Stephanie Lynn

    Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen

  12. Dynamic properties of Aluminum-Lithium and Aluminum-Magnesium melts

    Science.gov (United States)

    Kiselev, A. I.

    2010-08-01

    A comparison of calculated concentration dependences of the electrical resistivities of the Al-Li and Al-Mg systems suggests that a metal-nonmetal phase transition takes place in the Al-Li system. This assumption casts some doubt on the mechanism of quasi-chemical electron localization used to explain the metal-nonmetal phase transition in Pb-Li and Sn-Li melts.

  13. Towards refractive index sensitivity of long-period gratings at level of tens of µm per refractive index unit: fiber cladding etching and nano-coating deposition.

    Science.gov (United States)

    Śmietana, Mateusz; Koba, Marcin; Mikulic, Predrag; Bock, Wojtek J

    2016-05-30

    In this work we report experimental results on optimizing the refractive index (RI) sensitivity of long-period gratings (LPGs) by fiber cladding etching and thin aluminum oxide (Al2O3) overlay deposition. The presented LPG takes advantage of work in the dispersion turning point (DTP) regime as well as the mode transition (MT) effect for higher-order cladding modes (LP09 and LP010). The MT was obtained by depositing Al2O3 overlays with single-nanometer precision using the Atomic Layer Deposition method (ALD). Etching of both the overlay and the fiber cladding was performed using hydrofluoric acid (HF). For shallow etching of the cladding, i.e., DTP observed at next = 1.429 and 1.439 RIU for an LPG with no overlay, followed by deposition of an overlay of up to 167 nm in thickness, HF etching allowed for post-deposition fine-tuning of the overlay thickness resulting in a significant increase in RI sensitivity mainly at the DTP of the LP09 cladding mode. However, at an external RI (next) above 1.39 RIU, the DTP of LP010 was noticed, and its RI sensitivity exceeded 9,000 nm/RIU. Deeper etching of the cladding, i.e., DTP observed for next above 1.45 RIU, followed by the deposition of thicker overlays (up to 201 nm in thickness) allowed the sensitivity to reach values of over 40,000 nm/RIU in a narrow RI range. Sensitivity exceeding 20,000 nm/RIU was obtained in an RI range suitable for label-free biosensing applications.

  14. Tensile Hoop Behavior of Irradiated Zircaloy-4 Nuclear Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Jaramillo, Roger A [ORNL; Hendrich, WILLIAM R [ORNL; Packan, Nicolas H [ORNL

    2007-03-01

    A method for evaluating the room temperature ductility behavior of irradiated Zircaloy-4 nuclear fuel cladding has been developed and applied to evaluate tensile hoop strength of material irradiated to different levels. The test utilizes a polyurethane plug fitted within a tubular cladding specimen. A cylindrical punch is used to compress the plug axially, which generates a radial displacement that acts upon the inner diameter of the specimen. Position sensors track the radial displacement of the specimen outer diameter as the compression proceeds. These measurements coupled with ram force data provide a load-displacement characterization of the cladding response to internal pressurization. The development of this simple, cost-effective, highly reproducible test for evaluating tensile hoop strain as a function of internal pressure for irradiated specimens represents a significant advance in the mechanical characterization of irradiated cladding. In this project, nuclear fuel rod assemblies using Zircaloy-4 cladding and two types of mixed uranium-plutonium oxide (MOX) fuel pellets were irradiated to varying levels of burnup. Fuel pellets were manufactured with and without thermally induced gallium removal (TIGR) processing. Fuel pellets manufactured by both methods were contained in fuel rod assemblies and irradiated to burnup levels of 9, 21, 30, 40, and 50 GWd/MT. These levels of fuel burnup correspond to fast (E > 1 MeV) fluences of 0.27, 0.68, 0.98, 1.4 and 1.7 1021 neutrons/cm2, respectively. Following irradiation, fuel rod assemblies were disassembled; fuel pellets were removed from the cladding; and the inner diameter of cladding was cleaned to remove residue materials. Tensile hoop strength of this cladding material was tested using the newly developed method. Unirradiated Zircaloy-4 cladding was also tested. With the goal of determining the effect of the two fuel types and different neutron fluences on clad ductility, tensile hoop strength tests were

  15. Role of the micro/macro structure of welds in crack nucleation and propagation in aerospace aluminum-lithium alloy

    Science.gov (United States)

    Talia, George E.

    1996-01-01

    Al-Li alloys offer the benefits of increased strength, elastic modulus and lower densities as compared to conventional aluminum alloys. Martin Marietta Laboratories has developed an Al-Li alloy designated 2195 which is designated for use in the cryogenic tanks of the space shuttle. The Variable Polarity Plasma Arc (VPPA) welding process is currently being used to produce these welds [1]. VPPA welding utilizes high temperature ionized gas (plasma) to transfer heat to the workpiece. An inert gas, such as Helium, is used to shield the active welding zone to prevent contamination of the molten base metal with surrounding reactive atmospheric gases. [1] In the Space Shuttle application, two passes of the arc are used to complete a butt-type weld. The pressure of the plasma stream is increased during the first pass to force the arc entirely through the material, a practice commonly referred to as keyholing. Molten metal forms on either side of the arc and surface tension draws this liquid together as the arc passes. 2319 Al alloy filler material may also be fed into the weld zone during this pass. During the second pass, the plasma stream pressure is reduced such that only partial penetration of the base material is obtained. Al 2319 filler material is added during this pass to yield a uniform, fully filled welded joint. This additional pass also acts to alter the grain structure of the weld zone to yield a higher strength joint.

  16. Materials considerations in accelerator targets

    Science.gov (United States)

    Peacock, H. B.; Iyer, N. C.; Louthan, M. R.

    1995-09-01

    Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from, the coextruded product was modeled from experimental and operational data. The model assumed that tritium atoms, formed by the 6Li(n,a)3He reaction, were produced in solid solution in the Al-Li alloy. Because of the low solubility of hydrogen isotopes in aluminum alloys, the irradiated Al-Li rapidly became supersaturated in tritium. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes

  17. Cladding material, tube including such cladding material and methods of forming the same

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2016-03-01

    A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.

  18. Hollow Core Photonic Crystal Fibre Comprising a Fibre Grating in the Cladding and its Applications

    DEFF Research Database (Denmark)

    2010-01-01

    An optical fibre is provided having a fibre cladding around a longitudinally extending optical propagation core. The cladding has a reflection region of a varying refractive index in the longitudinal direction.......An optical fibre is provided having a fibre cladding around a longitudinally extending optical propagation core. The cladding has a reflection region of a varying refractive index in the longitudinal direction....

  19. Hollow core anti-resonant fiber with split cladding.

    Science.gov (United States)

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Yong, Ken-Tye; Luan, Feng; Yoo, Seongwoo

    2016-04-04

    An improved design for hollow core anti-resonant fibers (HAFs) is presented. A split cladding structure is introduced to reduce the fabrication distortion within design tolerance. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF and is comparable to that of the nested antiresonant nodeless fiber (NANF) with the same core size. In addition, the SCF allows stacking multiple layers of cladding rings to control the CL. The influences of the number of cladding layers and the cladding gap width on the CL of the SCFs have been studied. SCF with three cladding rings is fabricated by the stack-and-draw technique. A measured attenuation spectrum matches well with the calculation prediction. The measured near field mode patterns also prove the feasibility of our fiber design.

  20. Effect of Foam Cladding for Blast Mitigation: Numerical Simulation

    Institute of Scientific and Technical Information of China (English)

    MA Guowei; YE Ziqing; ZHANG Xingui

    2006-01-01

    Two numerical simulations were performed to investigate the protective effect of the foam cladding.One simulation is based on a previous experimental study,which is a ballistic pendulum with and without a foam cladding subjected to close-range blast loading.The other model is a steel beam with and without a foam cladding under blast loading.The overpressure due to the blast event can be calculated by the empirical function ConWep or by an arbitrary Lagrangian-Eulerian (ALE)coupling model.The first approach is relatively simple and widely used.The second approach can model the propagation of the blast wave in the air and the interaction between the air and the solid.Itis found that the pendulum with the foam cladding always swings to a larger rotation angel compared to a bare pendulum.However,the steel beam with an appropriate foam cladding has a smaller deflection compared to the bare beam without a foam cladding.It is concluded that the protective effect of the foam cladding depends on the properties of the foam and the protected structure.

  1. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B. [General Electric Global Research, Schnectady, NY (United States)

    2014-12-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  2. Ferritic Alloys as Accident Tolerant Fuel Cladding Material for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B. [General Electric Global Research, Schnectady, NY (United States)

    2014-09-30

    The objective of the GE project is to demonstrate that advanced steels such as iron-chromium-aluminum (FeCrAl) alloys could be used as accident tolerant fuel cladding material in commercial light water reactors. The GE project does not include fuel development. Current findings support the concept that a FeCrAl alloy could be used for the cladding of commercial nuclear fuel. The use of this alloy will benefit the public since it is going to make the power generating light water reactors safer. In the Phase 1A of this cost shared project, GE (GRC + GNF) teamed with the University of Michigan, Los Alamos National Laboratory, Brookhaven National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory to study the environmental and mechanical behavior of more than eight candidate cladding materials both under normal operation conditions of commercial nuclear reactors and under accident conditions in superheated steam (loss of coolant condition). The main findings are as follows: (1) Under normal operation conditions the candidate alloys (e.g. APMT, Alloy 33) showed excellent resistance to general corrosion, shadow corrosion and to environmentally assisted cracking. APMT also showed resistance to proton irradiation up to 5 dpa. (2) Under accident conditions the selected candidate materials showed several orders of magnitude improvement in the reaction with superheated steam as compared with the current zirconium based alloys. (3) Tube fabrication feasibility studies of FeCrAl alloys are underway. The aim is to obtain a wall thickness that is below 400 µm. (4) A strategy is outlined for the regulatory path approval and for the insertion of a lead fuel assembly in a commercial reactor by 2022. (5) The GE team worked closely with INL to have four rodlets tested in the ATR. GE provided the raw stock for the alloys, the fuel for the rodlets and the cost for fabrication/welding of the rodlets. INL fabricated the rodlets and the caps and welded them to

  3. Study on Cracking Tendency and Mechanism of Gray Cast Iron Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    YEHong; YANZhong-lin; HUANGQi; YANGHui

    2004-01-01

    In this paper, NiCrSiB and COWC35 powder has been used in laser cladding of gray cast iron. The cracking tendency has also been discussed. The cracks have been observed with a scan electron microscopy to analyze the cracking mechanism. The results show that cracks have not appeared in NiCrSiB cladding. Nevertheless, the cracking tendency of CoWC35 cladding is extremely high and there are both cold cracks and hot cracks in the cladding. The cracking tendency of laser cladding depends on physical properties of the cladding material and plasticity and roughness of the cladding.

  4. Study on Cracking Tendency and Mechanism of Gray Cast Iron Laser Cladding

    Institute of Scientific and Technical Information of China (English)

    YE Hong; YAN Zhong-lin; HUANG Qi; YANG Hui

    2004-01-01

    In this paper, NiCrSiB and CoWC35 powder has been used in laser cladding of gray cast iron. The cracking tendency has also been discussed. The cracks have been observed with a scan electron microscopy to analyze the cracking mechanism. The results show that cracks have not appeared in NiCrSiB cladding. Nevertheless, the cracking tendency of CoWC35 cladding is extremely high and there are both cold cracks and hot cracks in the cladding. The cracking tendency of laser cladding depends on physical properties of the cladding material and plasticity and roughness of the cladding.

  5. Weld overlay cladding with iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, G.M. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions have limited their use in applications where good weldability is required. Using hot crack testing techniques invented at ORNL, and experimental determinations of preheat and postweld heat treatment needed to avoid cold cracking, we have developed iron aluminide filler metal compositions which can be successfully used to weld overlay clad various substrate materials, including 9Cr-1Mo steel, 2-1/4Cr-1Mo steel, and 300-series austenitic stainless steels. Dilution must be carefully controlled to avoid crack-sensitive deposit compositions. The technique used to produce the current filler metal compositions is aspiration-casting, i.e. drawing the liquid from the melt into glass rods. Future development efforts will involve fabrication of composite wires of similar compositions to permit mechanized gas tungsten arc (GTA) and/or gas metal arc (GMA) welding.

  6. Bending of pipes with inconel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Nachpitz, Leonardo; Menezes, Carlos Eduardo B.; Vieira, Carlos R. Tavares [Primus Processamento de Tubos S.A. (PROTUBO), Macae, RJ (Brazil)

    2009-07-01

    The high-frequency induction bending process, using API pipes coated with Inconel 625 reconciled to a mechanical transformation for a higher degree of resistance, was developed through a careful specification and control of the manufacturing parameters and inherent heat treatments. The effects of this technology were investigated by a qualification process consisting of a sequence of tests and acceptance criteria typically required by the offshore industry, and through the obtained results was proved the effectiveness of this entire manufacturing process, without causing interference in the properties and the quality of the inconel cladding, adding a gain of resistance to the base material, guaranteed by the requirements of the API 5L Standard. (author)

  7. Deep-probe metal-clad waveguide biosensors

    DEFF Research Database (Denmark)

    Skivesen, Nina; Horvath, Robert; Thinggaard, S.

    2007-01-01

    Two types of metal-clad waveguide biosensors, so-called dip-type and peak-type, are analyzed and tested. Their performances are benchmarked against the well-known surface-plasmon resonance biosensor, showing improved probe characteristics for adlayer thicknesses above 150-200 nm. The dip-type metal......-clad waveguide sensor is shown to be the best all-round alternative to the surface-plasmon resonance biosensor. Both metal-clad waveguides are tested experimentally for cell detection, showing a detection linut of 8-9 cells/mm(2). (c) 2006 Elsevier B.V. All rights reserved....

  8. Long-range plasmonic waveguides with hyperbolic cladding.

    Science.gov (United States)

    Babicheva, Viktoriia E; Shalaginov, Mikhail Y; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V

    2015-11-30

    We study plasmonic waveguides with dielectric cores and hyperbolic multilayer claddings. The proposed design provides better performance in terms of propagation length and mode confinement in comparison to conventional designs, such as metal-insulator-metal and insulator-metal-insulator plasmonic waveguides. We show that the proposed structures support long-range surface plasmon modes, which exist when the permittivity of the core matches the transverse effective permittivity component of the metamaterial cladding. In this regime, the surface plasmon polaritons of each cladding layer are strongly coupled, and the propagation length can be on the order of a millimeter.

  9. Long-range plasmonic waveguides with hyperbolic cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia E.; Shalaginov, Mikhail Y.; Ishii, Satoshi;

    2015-01-01

    We study plasmonic waveguides with dielectric cores and hyperbolic multilayer claddings. The proposed design provides better performance in terms of propagation length and mode confinement in comparison to conventional designs, such as metal-insulator-metal and insulator-metal-insulator plasmonic...... waveguides. We show that the proposed structures support long-range surface plasmon modes, which exist when the permittivity of the core matches the transverse effective permittivity component of the metamaterial cladding. In this regime, the surface plasmon polaritons of each cladding layer are strongly...

  10. Innovations in laser cladding and direct metal deposition

    Science.gov (United States)

    Brückner, Frank; Nowotny, Steffen; Leyens, Christoph

    2012-03-01

    The present paper reviews recent progress in productivity, precision and quality of laser-based cladding and additive layer manufacturing. Recently, we have demonstrated the great benefits obtained from induction assisted laser cladding. This novel hybrid technology combines high deposition rates with excellent cladding properties. Laser-based direct metal deposition is a novel concept for the fabrication of components and repair as well as geometrical surface modifications. Newly developed nozzle design allows focused powder spots to generate wall thicknesses of about 30 μm. An in-depth understanding of the processes and the resulting materials properties is key for the development of technically viable and economically reasonable customized solutions.

  11. Linear inner cladding fiber amplifier suppressing mode instability

    Science.gov (United States)

    Li, Zebiao; Huang, Zhihua; Lin, Honghuan; Xu, Shanhui; Yang, Zhongmin; Wang, Jianjun; Jing, Feng

    2016-11-01

    We use a semi-analytical model considering pump power saturation in high power fiber laser systems of multi-kW-class to calculate mode instability threshold. A novel designed fiber, linear inner-cladding fiber, can mitigate mode instability effect by decreasing nonlinear coupling coefficient and smoothing heat profile along the fiber. We investigate strong pump absorption of linear inner-cladding fiber, leading to shorter fiber length. With 915 nm pumping, linear inner-cladding fiber can reach 10 kW output power without mode instability in theory.

  12. The Information Sources in Building Cladding Supply Chain

    Directory of Open Access Journals (Sweden)

    Qiang Du

    2012-11-01

    Full Text Available The increasing complexity of the cladding procurement and fragmentation of the supply chain bring challenges for information management. The purpose of this research was to identify the issues concerning the information sources. A questionnaire survey was the key method of this research, while industry meetings and informal interviews were employed to provide in-depth understanding of the communication related issues in the industry. It was found that the participants of the cladding supply chain were experiencing difficulties of identifying information sources and accessing information, and that an industry level third party acting as an independent information source could be accepted by the cladding industry.

  13. Roll caster for the three-layer clad-strip

    OpenAIRE

    Nakamura, R; T. Yamabayashi; T. Haga; S. Kumai; H. Watari

    2010-01-01

    Purpose: of this paper is to show the characteristics of two kinds of roll casters for three-layer clad strip of aluminium alloys. Moreover, the characteristics of these twin roll casters were compeered with the early type of roll casters for clad strip.Design/methodology/approach: Design was tried to attain the fabrication of the roll casters to cast the three-layers-clad-strip. One caster was an unequal diameter roll caster equipped with a scraper. The scraper was adopted to prevent the mix...

  14. Aspects of aluminum toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  15. Microstructure & performance of laser cladding on pick surface of coal mining machine

    Institute of Scientific and Technical Information of China (English)

    SUN Hui-lai; ZHAO Fang-fang; ZHANG Shou-xin; QI Xiang-yang

    2006-01-01

    Laser cladding of 316 L steel powders on pick substrate of coal mining machine was conducted, and microstructure of laser cladding coating was analyzed. The micro-hardness of laser cladding coating was examined. The results show that microstructure of laser cladding zone is exiguous dentrite, and there are hard spots dispersible distribution in the laser cladding zone. Performances of erode-resistant, surface micro-hardness and wear-resistant are improved obviously.

  16. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  17. A study of aluminum-lithium alloy solidification using acoustic emission techniques. Ph.D. Thesis, 1991

    Science.gov (United States)

    Henkel, Daniel P.

    1992-01-01

    Physical phenomena associated with the solidification of an aluminum lithium alloy was characterized using acoustic emission (AE) techniques. It is shown that repeatable patterns of AE activity may be correlated to microstructural changes that occur during solidification. The influence of the experimental system on generated signals was examined in the time and frequency domains. The analysis was used to show how an AE signal from solidifying aluminum is changed by each component in the detection system to produce a complex waveform. Conventional AE analysis has shown that a period of high AE activity occurs in pure aluminum, an Al-Cu alloy, and the Al-Li alloy, as the last fraction of solid forms. A model attributes this to the internal stresses of grain boundary formation. An additional period of activity occurs as the last fraction of solid forms, but only in the two alloys. A model attributes this to the formation of interdendritic porosity which was not present in the pure aluminum. The AE waveforms were dominated by resonant effects of the waveguide and the transducer.

  18. 时效处理对Al-Li二元合金力学性能的影响%Influence of aging treatment on mechanical properties of Al-Li binary alloys

    Institute of Scientific and Technical Information of China (English)

    梁宇; 王赫男; 刘春忠

    2015-01-01

    Al-1Li,Al-2Li and Al-3Li binary alloys were prepared by using vacuum induction melting fur-nace. The as-cast microstructure was observed with an optical microscopy and the phase transition tempera-tures of the three alloys were determined by differential scanning calorimetry( DSC). After solution and ag-ing treatment,the hardness of the three alloy samples were measured by using Vickers hardness tester. The Al-Li alloy samples were selected with different aging time and tensile test was conducted. The fracture mor-phologies of the samples were observed by scanning electron microscope( SEM ). The results indicate that both Al-2 Li alloy and Al-3 Li alloy have aging hardening and strengthening effects but Al-1 Li alloy does not. The maximum tensile strength of Al-1Li,Al-2Li and Al-3Li binary alloys are 63MPa,162MPa and 298MPa respectively. The tensile strength is increased and the toughness of Al-Li alloys is decreased with the growth of Li element. The fracture mechanism of alloys is changed to the brittle fracture from the ductile fracture due to Li addition.%采用真空感应熔炼炉制备Al-1Li、Al-2Li和Al-3Li二元合金,用金相显微镜观察其铸态组织,并用DSC确定其相转变温度。对3种合金进行固溶和时效处理,用维氏硬度计测量试样的硬度。选择具有不同时效时间的Al-Li合金进行拉伸实验,并用SEM观察断口形貌。结果表明:除Al-1Li合金外,Al-2Li和Al-3Li合金具有明显时效硬化和强化效应;Al-1Li、Al-2Li和Al-3Li合金的最大抗拉强度分别为63 MPa、162 MPa和298 MPa;合金元素Li在提高Al-Li合金强度的同时,导致其韧性降低,断裂由韧性向脆性转变。

  19. Manufacturing Technology and Application Trends of Titanium Clad Steel Plates

    Institute of Scientific and Technical Information of China (English)

    Hang SU; Xiao-bing LUO; Feng CHAI; Jun-chang SHEN; Xin-jun SUN; Feng LU

    2015-01-01

    Some of the major manufacturing processes and corresponding mechanical properties of titanium clad steel plates were analyzed, and the consequences of research, manufacturing, and application of titanium clad steel plates in both markets of China and overseas were also summarized. As an economical and environmentally friendly technology, the roll bonding process is ex-pected to become the next-generation mainstream process for the manufacturing of titanium clad steel plate. Some of the crucial and most important technical problems of this particular process, including vacuum sealing technology, surface treatment process technology, application of a transition layer, and rolling process, were discussed along with the advantageous mechanical properties and life-cycle economy of these plates processed by this technology. Finally, the market needs, application trends, and requirements of titanium clad steel plate were also considered from industries of petrochemical, shipbuilding, marine, and electric power.

  20. High Temperature Resistance Claddings for Nuclear Thermal Rockets Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program will develop a series of nano-/micro-composite coated nuclear reactor facing components using MesoCoat's CermaCladTM process. This proposed SBIR program...

  1. High Temperature Steam Corrosion of Cladding for Nuclear Applications: Experimental

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M; Garnier, John E; Sergey Rashkeev; Michael V. Glazoff; George W. Griffith; Shannong M. Bragg-Sitton

    2013-01-01

    Stability of cladding materials under off-normal conditions is an important issue for the safe operation of light water nuclear reactors. Metals, ceramics, and metal/ceramic composites are being investigated as substitutes for traditional zirconium-based cladding. To support down-selection of these advanced materials and designs, a test apparatus was constructed to study the onset and evolution of cladding oxidation, and deformation behavior of cladding materials, under loss-of-coolant accident scenarios. Preliminary oxidation tests were conducted in dry oxygen and in saturated steam/air environments at 1000OC. Tube samples of Zr-702, Zr-702 reinforced with 1 ply of a ß-SiC CMC overbraid, and sintered a-SiC were tested. Samples were induction heated by coupling to a molybdenum susceptor inside the tubes. The deformation behavior of He-pressurized tubes of Zr-702 and SiC CMC-reinforced Zr-702, heated to rupture, was also examined.

  2. Jet slurry erosion performance of composite clad and its characterization

    Science.gov (United States)

    B, Lohit R.; Horakeri, Gururaj S.; Bhovi, Prabakhar M.

    2016-09-01

    In the present work, development of composite cladding consists of Cr23C6 (chromium carbide) as reinforcement particles 20 wt. % in Ni-based matrix 80 wt. % on austenitic stainless steel through exposure of microwave radiation has been carried out. The jet slurry erosion test was performed on microwave composite clad. The functional performance of composite clad has been evaluated for different parametric conditions like varying impingement velocity and impact angle. The increasing weight loss trend was observed with time for the first 30 min. after that the individual trend decreased; at high impingement velocity and maximum impact angle. SEM micrographs of eroded clad samples at various impact angle and impingement velocity were discussed. The maximum weight loss occurred at 90° angle and velocity of 60 m/s, and minimum at 30° angle and velocity of 20 m/s.

  3. Properties of multilayer coatings produced by coaxial laser cladding

    Science.gov (United States)

    Petrovskiy, V. N.; Bykovskiy, D. P.; Dzhumaev, P. S.; Polskiy, V. I.; Prokopova, N. M.; Chirikov, S. N.

    2016-09-01

    This article contains results of the study of multilayer coatings produced by laser cladding on the substrate steel 34HMA using iron based powder PR-10R6M5 as the filler material. The coatings were produced with consistent application of the tracks with fixed overlapping. The dependencies between the characteristics of tracks and the technological mode of deposition were revealed. Properties of coatings were determined for various overlapping of tracks and directions of the cladding layers.

  4. Cladding for transverse-pumped solid-state laser

    Science.gov (United States)

    Byer, Robert L. (Inventor); Fan, Tso Y. (Inventor)

    1989-01-01

    In a transverse pumped, solid state laser, a nonabsorptive cladding surrounds a gain medium. A single tranverse mode, namely the Transverse Electromagnetic (TEM) sub 00 mode, is provided. The TEM sub 00 model has a cross sectional diameter greater than a transverse dimension of the gain medium but less than a transverse dimension of the cladding. The required size of the gain medium is minimized while a threshold for laser output is lowered.

  5. Theoretical analysis of radiation-balanced double clad fiber laser

    Institute of Scientific and Technical Information of China (English)

    CHEN Ji-xin; SUI Zhan; CHEN Fu-shen; LI Ming-zhong; WANG Jian-jun

    2005-01-01

    In this letter,a theoretical model of radiation-balanced double clad fiber laser is presented.The characteristic of the laser with Yb doped double clad fiber is analyzed numerically.It is concluded that high output laser power can be obtained by selecting output coupling mirror with lower reflectivity,improving Yb doped concentration and choosing fiber length. This result can help us to design radiation balanced fiber laser.

  6. Surface treatment method for cladding tube of LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suda, Yoshitaka; Matsumoto, Kunio; Ito, Kenji.

    1994-06-07

    Upon surface finishing by polishing, shot peening or blasting is applied on the outer surface of a cladding tube to eliminate orientation of residual stresses on the surface layer in order to eliminate residual stresses formed on the outer surface in the circumferential direction. This can suppress occurrence of cracks in oxide membranes formed on the outer surface to suppress development of corrosion on the outer surface irrespective of the ingredient composition of fuel cladding tube made of zircaloy. (T.M.).

  7. Is the Aluminum Hypothesis Dead?

    OpenAIRE

    Lidsky, Theodore I.

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed w...

  8. High energy density aluminum battery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  9. Evolutionary developments of advanced PWR nuclear fuels and cladding materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyu-Tae, E-mail: ktkim@dongguk.ac.kr

    2013-10-15

    Highlights: • PWR fuel and cladding materials development processes are provided. • Evolution of PWR advanced fuel in U.S.A. and in Korea is described. • Cutting-edge design features against grid-to-rod fretting and debris are explained. • High performance data of advanced grids, debris filters and claddings are given. -- Abstract: The evolutionary developments of advanced PWR fuels and cladding materials are explained with outstanding design features of nuclear fuel assembly components and zirconium-base cladding materials. The advanced PWR fuel and cladding materials development processes are also provided along with verification tests, which can be used as guidelines for newcomers planning to develop an advanced fuel for the first time. The up-to-date advanced fuels with the advanced cladding materials may provide a high level of economic utilization and reliable performance even under current and upcoming aggressive operating conditions. To be specific, nuclear fuel vendors may achieve high fuel burnup capability of between 45,000 and 65,000 MWD/MTU batch average, overpower thermal margin of as much as 15% and longer cycle length up to 24 months on the one hand and fuel failure rates of around 10{sup −6} on the other hand. However, there is still a need for better understanding of grid-to-rod fretting wear mechanisms leading to major PWR fuel defects in the world and subsequently a driving force for developing innovative spacer grid designs with zero fretting wear-induced fuel failure.

  10. Fuel clad chemical interactions in fast reactor MOX fuels

    Science.gov (United States)

    Viswanathan, R.

    2014-01-01

    Clad corrosion being one of the factors limiting the life of a mixed-oxide fast reactor fuel element pin at high burn-up, some aspects known about the key elements (oxygen, cesium, tellurium, iodine) in the clad-attack are discussed and many Fuel-Clad-Chemical-Interaction (FCCI) models available in the literature are also discussed. Based on its relatively superior predictive ability, the HEDL (Hanford Engineering Development Laboratory) relation is recommended: d/μm = ({0.507 ṡ [B/(at.% fission)] ṡ (T/K-705) ṡ [(O/M)i-1.935]} + 20.5) for (O/M)i ⩽ 1.98. A new model is proposed for (O/M)i ⩾ 1.98: d/μm = [B/(at.% fission)] ṡ (T/K-800)0.5 ṡ [(O/M)i-1.94] ṡ [P/(W cm-1)]0.5. Here, d is the maximum depth of clad attack, B is the burn-up, T is the clad inner surface temperature, (O/M)i is the initial oxygen-to-(uranium + plutonium) ratio, and P is the linear power rating. For fuels with [n(Pu)/n(M = U + Pu)] > 0.25, multiplication factors f are recommended to consider the potential increase in the depth of clad-attack.

  11. Laser multi-layer cladding of Mg-based alloys

    Institute of Scientific and Technical Information of China (English)

    陈长军; 王东生; 王茂才

    2003-01-01

    By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1. 0 mm. The microstructure of the substrate and the cladding zone wasstudied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hard-ness analysis. It is observed that constituent of ZM5 alloy is δ+Mg17 Al12, that of ZM2 alloy is α+MgZn+Mg9Ce.That of cladding layer ZM2 alloy(L-ZM2) is Mg+ Mg2 Zn11 +MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg32 (Al, Zn)49. The hardness of the cladding area can be increased to values above HV127. Veryfine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now,many repaired Mg-based alloy components have been passed by flying test in outside field.

  12. Is the Aluminum Hypothesis dead?

    Science.gov (United States)

    Lidsky, Theodore I

    2014-05-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust.

  13. Anodizing Aluminum with Frills.

    Science.gov (United States)

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

  14. 铝锂合金中原子簇聚和有序化的计算机模拟研究%Investigations on Ordering and Atom Clustering in Al-Li Alloy by Computer Simulation

    Institute of Scientific and Technical Information of China (English)

    李晓玲; 陈铮; 王永欣; 胡明娟

    2006-01-01

    通过计算机模拟对铝锂合金时效过程中的有序化和原子簇聚进行了研究.长程序参数和成分偏离序参数通过锂原子格点占位几率计算得出.结果表明:随合金成分由相图上的亚稳区向失稳区转变,有序化与原子簇聚过程相比逐渐加快,而相变孕育期逐渐缩短.%Investigations on the ordering and atom clustering in aged binary Al-Li alloy have been carried out by computer simulation. The long range order parameter (lro.) and composition deviation order parameter were calculated from single-site occupation probabilities of Li atom. The results show that as the composition of the alloy increases from metastable region to instable region in the phase diagram ordering occurs faster than atom clustering gradually and the incubation period of the phase transformation is shortened.

  15. Comparison of fiber lasers based on distributed side-coupled cladding-pumped fibers and double-cladding fibers.

    Science.gov (United States)

    Huang, Zhihe; Cao, Jianqiu; Guo, Shaofeng; Chen, Jinbao; Xu, Xiaojun

    2014-04-01

    We compare both analytically and numerically the distributed side-coupled cladding-pumped (DSCCP) fiber lasers and double cladding fiber (DCF) lasers. We show that, through optimization of the coupling and absorbing coefficients, the optical-to-optical efficiency of DSCCP fiber lasers can be made as high as that of DCF lasers. At the same time, DSCCP fiber lasers are better than the DCF lasers in terms of thermal management.

  16. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  17. Mechanical Property and Oxidation Behavior of ATF cladding developed in KAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Gil; Kim, Il-Hyun; Jung, Yang-Il; Park, Dong-Jun; Park, Jung-Hwan; Park, Jeong-Yong; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    To realize the coating cladding, coating material (Cr-based alloy) as well as coating technology (3D laser coating and arc ion plating combined with vacuum annealing) can be developed to meet the fuel cladding criteria. The coated Zr cladding can be produced after the optimization of coating technologies. The coated cladding sample showed the good oxidation/corrosion and adhesion properties without the spalling and/or severe interaction with the Zr alloy cladding from the various tests. Thus, it is known that the mechanical property and oxidation behavior of coated cladding concept developed in KAERI is reasonable for applying the ATF cladding in LWRs. At the present time various ATF concepts have been proposed and developing in many countries. The ATF concepts with potentially improved accident performance can be summarized to the coating cladding, Mo-Zr cladding, FeCrAl cladding, and SiCf/SiC cladding. Regarding the cladding performance, ATF cladding concepts will be evaluated with respect to the accident scenarios and normal operations of LWRs as well as to the fuel cladding fabrication.

  18. Bragg grating induced cladding mode coupling due to asymmetrical index modulation in depressed cladding fibers

    DEFF Research Database (Denmark)

    Berendt, Martin Ole; Grüne-Nielsen, Lars; Soccolich, C.F.

    1998-01-01

    to reduce this problem. None of these designs seems to give complete solutions. In particular, the otherwise promising depressed cladding design gives a pronounced coupling to one LP01 mode, this has been referred to as a Ghost grating. To find the modes of the fiber we have established a numerical mode......-solver based on the staircase-approximation method. The Bragg grating causes coupling between the fundamental LP01 mode and higher order LP1p modes that satisfy phase-matching. The coupling strength is determined by the overlap integral of the LP01, the LP1p mode, and the UV-induced index perturbation. For LP0...

  19. Microstructure and properties of the Ti/Al{sub 2}O{sub 3}/NiCr composites fabricated by explosive compaction/cladding

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bingfeng, E-mail: biw009@ucsd.edu [School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Departments of Mechanical and Aerospace Engineering and Nanoengineering, University of California, San Diego (United States); Key Lab of Nonferrous Materials, Ministry of Education, Central South University, Changsha, Hunan (China); Xie, Fangyu [School of Materials Science and Engineering, Central South University, Changsha, Hunan (China); Wang, Bin [Departments of Mechanical and Aerospace Engineering and Nanoengineering, University of California, San Diego (United States); Luo, Xiaozhou [School of Materials Science and Engineering, Central South University, Changsha, Hunan (China)

    2015-05-01

    Titanium/aluminum oxide/nickel chromium (Ti/Al{sub 2}O{sub 3}/NiCr) composite bar prepared by explosive compaction/cladding technique represents a new kind of sandwich-structural composites for medical application. Formation of the interfaces of Ti/Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}/NiCr govern the properties of the composite material. The electrical resistivity and microstructure of the intermediate layer and the interfaces of the Ti/Al{sub 2}O{sub 3}/NiCr explosive compaction/cladding bar are investigated by means of four-point probe analysis, optical microscopy, scanning electron microscopy, electron microprobe analysis, and X-ray diffraction. The Ti/Al{sub 2}O{sub 3}/NiCr composite bar is characterized by the consolidated ceramic intermediate layer and the metallurgical bonding interfaces. The intermediate ceramic layer plays a role of insulation and thermal conductance in this composite. The average shear strength of the composite bar is about 9.36 MPa. The heat affected zone characterized by relatively larger sizes of grains is distinguished from the other part of the Ti tube. The intermetallics AlTi{sub 3} and Al{sub 0.9}Ni{sub 4.22} are generated at the intermediate ceramic layer. Formation mechanism of the interfaces of the explosive compaction/cladding bar are described. - Highlights: • Ti/Al{sub 2}O{sub 3}/NiCr composite bar is prepared by explosive compaction/cladding technique. • Consolidated intermediate ceramic layer plays insulation role in the cladding bar. • Ti/Al{sub 2}O{sub 3}/NiCr composite bar has the metallurgical bonding interfaces. • Formation mechanism of the interface of the composite bar is proposed.

  20. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States); Lepage, R. [Building Science Corporation, Somerville, MA (United States)

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1.What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2.Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3.What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  1. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  2. Clinical biochemistry of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    King, S.W.; Savory, J.; Wills, M.R.

    1981-05-01

    Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

  3. Vanadium diffusion coating on HT-9 cladding for mitigating the fuel cladding chemical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Wei-Yang; Yang, Yong, E-mail: yongyang@ufl.edu

    2014-08-01

    Fuel cladding chemical interaction (FCCI) has been identified as one of the crucial issues for developing Ferritic/Martensitic (F/M) stainless steel claddings for metallic fuels in a fast reactor. The anticipated elevated temperature and high neutron flux can significantly aggravate the FCCI, in terms of formation of inter-diffusion and lower melting point eutectic phases. To mitigate the FCCI, vanadium carbide coating as a diffusion barrier was deposited on the HT-9 substrate using a pack cementation diffusion coating (PCDC) method, and the processing temperature was optimized down to 730 °C. A solid metallurgical bonding between the coating layer and substrate was achieved, and the coating is free from through depth cracks. The microstructural characterizations using SEM and TEM show a nanostructured grain structure. EDS/WDS and XRD analysis confirm the phase of coating layer as V{sub 2}C. Diffusion couple tests at 660 °C for 100 h demonstrate that V{sub 2}C layer with a thickness of less than 5 μm can effectively eliminate the inter-diffusion between the lanthanide cerium and HT-9 steel.

  4. Vanadium diffusion coating on HT-9 cladding for mitigating the fuel cladding chemical interactions

    Science.gov (United States)

    Lo, Wei-Yang; Yang, Yong

    2014-08-01

    Fuel cladding chemical interaction (FCCI) has been identified as one of the crucial issues for developing Ferritic/Martensitic (F/M) stainless steel claddings for metallic fuels in a fast reactor. The anticipated elevated temperature and high neutron flux can significantly aggravate the FCCI, in terms of formation of inter-diffusion and lower melting point eutectic phases. To mitigate the FCCI, vanadium carbide coating as a diffusion barrier was deposited on the HT-9 substrate using a pack cementation diffusion coating (PCDC) method, and the processing temperature was optimized down to 730 °C. A solid metallurgical bonding between the coating layer and substrate was achieved, and the coating is free from through depth cracks. The microstructural characterizations using SEM and TEM show a nanostructured grain structure. EDS/WDS and XRD analysis confirm the phase of coating layer as V2C. Diffusion couple tests at 660 °C for 100 h demonstrate that V2C layer with a thickness of less than 5 μm can effectively eliminate the inter-diffusion between the lanthanide cerium and HT-9 steel.

  5. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  6. Ultra-Low Index and Rad-Hard Total Internal Reflection Claddings for High Numerical Aperture Scintillating, Waveshifting, Cerenkov, or Clear Optical Fibers, Capillaries, and Plates

    CERN Document Server

    Sanzeni, C; Winn, D R

    2013-01-01

    Novel low index (n less than 1.3)/high light trapping cladding films consisting of nanoporous alumina (sapphire), as formed by controlled anodization of aluminum, are described. These films are mechanically hard, intrinsically very rad-hard, and have an index of refraction n sufficiently small to triple the light capture of waveshifting or scintillating fibers and transparent plastic, glass or quartz core fibers. The low indices enable light-piping of water Cerenkov light. Applications are in Energy, Intensity, and Cosmic/Astroparticle detectors.

  7. Improving 6061-Al Grain Growth and Penetration across HIP-Bonded Clad Interfaces in Monolithic Fuel Plates: Initial Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hackenberg, Robert E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McCabe, Rodney J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Edwards, Randall L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trujillo, R. Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollis, Kendall J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lienert, Thomas J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Forsyth, Robert T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harada, Kiichi L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-05-06

    Grain penetration across aluminum-aluminum cladding interfaces in research reactor fuel plates is desirable and was obtained by a legacy roll-bonding process, which attained 20-80% grain penetration. Significant grain penetration in monolithic fuel plates produced by Hot Isostatic Press (HIP) fabrication processing is equally desirable but has yet to be attained. The goal of this study was to modify the 6061-Al in such a way as to promote a much greater extent of crossinterface grain penetration in monolithic fuel plates fabricated by the HIP process. This study documents the outcomes of several strategies attempted to attain this goal. The grain response was characterized using light optical microscopy (LOM) electron backscatter diffraction (EBSD) as a function of these prospective process modifications done to the aluminum prior to the HIP cycle. The strategies included (1) adding macroscopic gaps in the sandwiches to enhance Al flow, (2) adding engineering asperities to enhance Al flow, (3) adding stored energy (cold work), and (4) alternative cleaning and coating. Additionally, two aqueous cleaning methods were compared as baseline control conditions. The results of the preliminary scoping studies in all the categories are presented. In general, none of these approaches were able to obtain >10% grain penetration. Recommended future work includes further development of macroscopic grooving, transferred-arc cleaning, and combinations of these with one another and with other processes.

  8. Optical monitoring of high power direct diode laser cladding

    Science.gov (United States)

    Liu, Shuang; Farahmand, Parisa; Kovacevic, Radovan

    2014-12-01

    Laser cladding is one of the most advanced surface modification techniques which can be used to build and repair high-value components. High power direct diode laser (HPDDL) offers unique quality and cost advantages over other lasers (CO2, Nd:YAG). Especially its rectangular laser beam with top-hat intensity distribution makes HPDDL an ideal tool for large area cladding. In order to utilize this technique successfully, the development of on-line monitoring and process control is necessary. In this study, an optical monitoring system consisting of a high-speed CCD camera, a pyrometer, and an infrared camera was used to analyze the mass- and heat-transfer in the cladding process. The particle transport in flight was viewed by a high-speed CCD camera; the interaction between powder flow and laser beam was observed by an infrared camera; and the thermal behavior of the molten pool was recorded by the pyrometer and the infrared camera. The effects of the processing parameters on the laser attenuation, particle heating and clad properties were investigated based on the obtained signals. The optical monitoring method improved the understanding about mutual interrelated phenomena in the cladding process.

  9. Laser cladding of Ni-based alloy on copper substrate

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Changsheng Liu; Xingqi Tao; Suiyuan Chen

    2006-01-01

    The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate (Hv 85). OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of (Cu, Ni) solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.

  10. Cladding Alloys for Fluoride Salt Compatibility Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Wilson, Dane F [ORNL; Santella, Michael L [ORNL; Holcomb, David Eugene [ORNL

    2011-05-01

    This interim report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for coating large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for coating inaccessible surfaces such as the interior surfaces of heat exchangers. The final project report will feature an experimental evaluation of the performance of the two selected cladding techniques.

  11. A simple but realistic model for laser cladding

    Energy Technology Data Exchange (ETDEWEB)

    Picasso, M.; Marsden, C.F.; Wagniere, J.D.; Frenk, A.; Rappaz, M. (Ecole Polytechnique Federale de Lausanne (Switzerland))

    1994-04-01

    The steady development of high-power lasers has encouraged the industrial application of laser surface treatments. The aim of the laser-cladding process is to deposit a protective layer (from 0.1 to 1.5 mm) onto a workpiece and for the two to be joined by a fusion bond. A model which takes into account the main phenomena occurring during the laser-cladding process is proposed. For a given laser power, beam radius, powder jet geometry, and clad height, this model evaluates two other processing parameters, namely, the laser-beam velocity and the powder feed rate. It considers the interactions between the powder particles, the laser beam, and the molten pool. The laser power reaching the surface of the workpiece is estimated and, assuming this power is used to remelt the substrate with the clad having been predeposited, the melt-pool shape is computed using a three-dimensional (3-D) analytical model, which produces immediate results, even on personal computers. The predictions obtained with this numerical model are in good agreement with experimental results. Processing engineers may therefore use this model to choose the correct processing parameters and to establish cladding maps.

  12. Evaluation of alternative descriptions of PWR cladding corrosion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Quecedo, M.; Serna, J. J.; Weiner, R. A.; Kersting, P. J.

    1999-05-15

    A statistical procedure has been used to evaluate several alternative descriptions of pressurized water reactor (PWR) cladding corrosion behavior, using an extensive database of Improved (low tin) Zr-4 cladding corrosion measurements from fuel irradiated in commercial PWRs. The in-reactor corrosion enhancement factors considered in the model development are based on a comprehensive review of the current literature for PWR cladding corrosion phenomenology and models. In addition, because prediction of PWR cladding corrosion behavior is very sensitive to the values used for the oxide surface temperatures, several models for the forced convection and sub-cooled nucleate boiling (SNB) coolant heat transfer under PWR conditions have also been evaluated. This evaluation determined that the choice of the forced convection heat transfer has the greatest impact on the ability to fit the data. In addition, the SNB heat transfer model used must account for a continuous transition from forced convection conditions to fully developed SNB conditions. With these choices for the heat transfer models, the evaluation determined that the significant in-reactor corrosion enhancement factors are related to the formation of a hydride rim at the cladding outer diameter, the coolant lithium concentration, and the fast neutron fluence (author) (ml)

  13. The effect of fabrication on corrosion in aluminum 2195: Environmental and microstructural considerations

    Science.gov (United States)

    Walsh, Daniel W.

    1994-01-01

    Aluminum alloys containing lithium are particularly attractive to the aerospace structural designer. Lithium's density is only 0.53 g/cc, thus an addition of one weight percent lithium not only increases yield strength, but decreases the density by almost three percent while increasing the modulus by over six percent. The fact that lithium improves these physical properties simultaneously has led to intense study and development of the alloy system. Heretofore, problems in large scale alloy production have retarded commercial development. During the last fifteen years, advances in production technology have rekindled interest in Al-Li alloys, and aluminum suppliers have developed many candidate aerospace materials. However, if these alloys are to be employed successfully, a more complete understanding of their nonequilibrium metallurgy is required. Peel and Starke have each pointed out that an understanding of the weldability of these alloys is a critical step in their implementation. This study addresses the critical lack of information on the environmental compatibility of welded Al 2195 components. Corrosion data for these systems is incomplete, particularly for welded materials exposed to sea water or sea water condensate.

  14. Microstructure and Wear Behaviour of Laser-Induced Thermite Reaction Al2O3 Ceramic Coatings on Pure Aluminum and AA7075 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    HUANG Kaijin; LIN Xin; XIE Changsheng; T M Yue

    2008-01-01

    Wear-resistant laser-induced thermite reaction Al2O3 ceramic coatings can be fabricated on pure Al and AA7075 aluminum alloy by laser cladding(one-step method)and laser cladding followed by laser re-melting(two-step method)using mixed powders CuO-Al-SiO2 in order to improve the wear properties of aluminum and aluminum alloy,respectively.The microstructure of the coatings was characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The wear resistance of the coatings was evaluated under dry sliding wear test condition at room temperature.Owing to the presence of hard a-Al2O3 and γ-Al2O,3phases,the coatings exhibited excellent wear resistance.In addition,the wear resistance of the coatings fabricated by two-step method is superior to that of the coatings fabricated by one-step method.

  15. Development of advanced LWR fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong Hwan; Park, S. Y.; Lee, M. H. [and others

    2000-04-01

    This report describes the results from evaluating the preliminary Zr-based alloys to develop the advanced Zr-based alloys for the nuclear fuel claddings, which should have good corrosion resistance and mechanical properties at high burn-up over 70,000MWD/MTU. It also includes the results from the basic studies for optimizing the processes which are involved in the development of the advanced Zr-based alloys. Ten(10) kinds of candidates for the alloys of which performance is over that of the existing Zircaloy-4 or ZIRLO alloy were selected out of the preliminary alloys of 150 kinds which were newly designed and repeatedly manufactured and evaluated to find out the promising alloys. First of all, the corrosion tests on the preliminary alloys were carried out to evaluate their performance in both pure water and LiOH solution at 360 deg C and in steam at 400 deg C. The tensile tests were performed on the alloys which proved to be good in the corrosion resistance. The creep behaviors were tested at 400 deg C for 10 days with the application of constant load on the samples which showed good performance in the corrosion resistance and tensile properties. The effect of the final heat treatment and A-parameters as well as Sn or Nb on the corrosion resistance, tensile properties, hardness, microstructures of the alloys was evaluated for some alloys interested. The other basic researches on the oxides, electrochemical properties, corrosion mechanism, and the establishment of the phase diagrams of some alloys were also carried out.

  16. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  17. Advances in aluminum anodizing

    Science.gov (United States)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  18. CORROSION PROTECTION OF ALUMINUM

    Science.gov (United States)

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  19. Low-Stress Silicon Cladding for Surface Finishing Large UVOIR Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I research, ZeCoat Corporation demonstrated a low-stress silicon cladding process for surface finishing large UVOIR mirrors. A polishable cladding is...

  20. Metaliographic Analyses of Laser Cladded WC-Ni and WC-Co Hard-facing Metals

    Institute of Scientific and Technical Information of China (English)

    HKChikwanda; MChiremba; CVanRooyen

    2004-01-01

    Laser cladding is performed to improve the surface properties of metallic machine components. Extensive work is being conducted to investigate the relationships among the cladding parameters, clad powder characteristics and the quality of the clad layer. This work presents some of the metallographic analyses results of WC-Ni and WC-Co clad layers. The clad layers are chayacterised with non-uniform carbide par[icles, mostly WC imbedded in a more ductile matrix. The transition from the clad layer to the subslxate metal had a distinct dilution zone. The ratio of this zone to the clad height was in the range of 10-12% and this still needs robe refined.

  1. Complete Non-Radioactive Operability Tests for Cladding Hull Chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Emory D [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Jared A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hylton, Tom D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brunson, Ronald Ray [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunt, Rodney Dale [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DelCul, Guillermo Daniel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bradley, Eric Craig [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Spencer, Barry B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    Non-radioactive operability tests were made to test the metal chlorination reactor and condenser and their accessories using batch chlorinations of non-radioactive cladding samples and to identify optimum operating practices and components that need further modifications prior to installation of the equipment into the hot cell for tests on actual used nuclear fuel (UNF) cladding. The operability tests included (1) modifications to provide the desired heating and reactor temperature profile; and (2) three batch chlorination tests using, respectively, 100, 250, and 500 g of cladding. During the batch chlorinations, metal corrosion of the equipment was assessed, pressurization of the gas inlet was examined and the best method for maintaining solid salt product transfer through the condenser was determined. Also, additional accessing equipment for collection of residual ash and positioning of the unit within the hot cell were identified, designed, and are being fabricated.

  2. Nanoscale light-matter interactions in atomic cladding waveguides.

    Science.gov (United States)

    Stern, Liron; Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

    2013-01-01

    Alkali vapours, such as rubidium, are being used extensively in several important fields of research such as slow and stored light nonlinear optics quantum computation, atomic clocks and magnetometers. Recently, there is a growing effort towards miniaturizing traditional centimetre-size vapour cells. Owing to the significant reduction in device dimensions, light-matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for nonlinear interactions. Here, taking advantage of the mature platform of silicon photonics, we construct an efficient and flexible platform for tailored light-vapour interactions on a chip. Specifically, we demonstrate light-matter interactions in an atomic cladding waveguide, consisting of a silicon nitride nano-waveguide core with a rubidium vapour cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and show that due to the high confinement of the optical mode, the rubidium absorption saturates at powers in the nanowatt regime.

  3. Clad thickness variation N-Reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E.A.

    1966-05-12

    The current specifications for the cladding on {open_quotes}N{close_quotes} fuels were established early in the course of process development and were predicted on several basic considerations. Among these were: (a) a desire to provide an adequate safety factor in cladding thickness to insure against corrosion penetration and rupture from uranium swelling stresses; (b) an apprehension that the striations in the zircaloy cladding of the U/zircaloy interface and on the exterior surface might serve as stress-raisers, leading to untimely failures of the jacket; and (c) then existing process capability - the need to maintain a specified ratio between zircaloy and uranium in the billet assembly to effect satisfactory coextrusion. It now appears appropriate to review these specifications in an effort to determine whether some of them may be revised, with attendant gains in economy and/or operating smoothness.

  4. Laser cladding of Ni-based alloy on stainless steel

    Institute of Scientific and Technical Information of China (English)

    XUE Chun-fang; TIAN Xin-li; TAN Yong-sheng; WU Zhi-yuan

    2004-01-01

    The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

  5. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating

    OpenAIRE

    2016-01-01

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending ...

  6. Results of NDE Technique Evaluation of Clad Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Kunerth, Dennis C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report fulfills the M4 milestone, M4FT-14IN0805023, Results of NDE Technique Evaluation of Clad Hydrides, under Work Package Number FT-14IN080502. During service, zirconium alloy fuel cladding will degrade via corrosion/oxidation. Hydrogen, a byproduct of the oxidation process, will be absorbed into the cladding and eventually form hydrides due to low hydrogen solubility limits. The hydride phase is detrimental to the mechanical properties of the cladding and therefore it is important to be able to detect and characterize the presence of this constituent within the cladding. Presently, hydrides are evaluated using destructive examination. If nondestructive evaluation techniques can be used to detect and characterize the hydrides, the potential exists to significantly increase test sample coverage while reducing evaluation time and cost. To demonstrate the viability this approach, an initial evaluation of eddy current and ultrasonic techniques were performed to demonstrate the basic ability to these techniques to detect hydrides or their effects on the microstructure. Conventional continuous wave eddy current techniques were applied to zirconium based cladding test samples thermally processed with hydrogen gas to promote the absorption of hydrogen and subsequent formation of hydrides. The results of the evaluation demonstrate that eddy current inspection approaches have the potential to detect both the physical damage induced by hydrides, e.g. blisters and cracking, as well as the combined effects of absorbed hydrogen and hydride precipitates on the electrical properties of the zirconium alloy. Similarly, measurements of ultrasonic wave velocities indicate changes in the elastic properties resulting from the combined effects of absorbed hydrogen and hydride precipitates as well as changes in geometry in regions of severe degradation. However, for both approaches, the signal responses intended to make the desired measurement incorporate a number of contributing

  7. Ceramic Coatings for Clad (The C3 Project): Advanced Accident-Tolerant Ceramic Coatings for Zr-Alloy Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Sickafus, Kurt E. [Univ. of Tennessee, Knoxville, TN (United States); Wirth, Brian [Univ. of Tennessee, Knoxville, TN (United States); Miller, Larry [Univ. of Tennessee, Knoxville, TN (United States); Weber, Bill [Univ. of Tennessee, Knoxville, TN (United States); Zhang, Yanwen [Univ. of Tennessee, Knoxville, TN (United States); Patel, Maulik [Univ. of Tennessee, Knoxville, TN (United States); Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Wolfe, Doug [Pennsylvania State Univ., University Park, PA (United States); Fratoni, Max [Univ. of California, Berkeley, CA (United States); Raj, Rishi [Univ. of Colorado, Boulder, CO (United States); Plunkett, Kenneth [Univ. of Colorado, Boulder, CO (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Hollis, Kendall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Andy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stanek, Chris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Comstock, Robert [Westinghouse Electric Corporation, Pittsburgh, PA (United States); Partezana, Jonna [Westinghouse Electric Corporation, Pittsburgh, PA (United States); Whittle, Karl [Univ. of Sheffield (United Kingdom); Preuss, Michael [Univ. of Manchester (United Kingdom); Withers, Philip [Univ. of Manchester (United Kingdom); Wilkinson, Angus [Univ. of Oxford (United Kingdom); Donnelly, Stephen [Univ. of Huddersfield (United Kingdom); Riley, Daniel [Australian Nuclear Science and Technology Organisation, Syndney (Australia)

    2017-02-14

    The goal of this NEUP-IRP project is to develop a fuel concept based on an advanced ceramic coating for Zr-alloy cladding. The coated cladding must exhibit demonstrably improved performance compared to conventional Zr-alloy clad in the following respects: During normal service, the ceramic coating should decrease cladding oxidation and hydrogen pickup (the latter leads to hydriding and embrittlement). During a reactor transient (e.g., a loss of coolant accident), the ceramic coating must minimize or at least significantly delay oxidation of the Zr-alloy cladding, thus reducing the amount of hydrogen generated and the oxygen ingress into the cladding. The specific objectives of this project are as follows: To produce durable ceramic coatings on Zr-alloy clad using two possible routes: (i) MAX phase ceramic coatings or similar nitride or carbide coatings; and (ii) graded interface architecture (multilayer) ceramic coatings, using, for instance, an oxide such as yttria-stabilized zirconia (YSZ) as the outer protective layer. To characterize the structural and physical properties of the coated clad samples produced in 1. above, especially the corrosion properties under simulated normal and transient reactor operating conditions. To perform computational analyses to assess the effects of such coatings on fuel performance and reactor neutronics, and to perform fuel cycle analyses to assess the economic viability of modifying conventional Zr-alloy cladding with ceramic coatings. This project meets a number of the goals outlined in the NEUP-IRP call for proposals, including: Improve the fuel/cladding system through innovative designs (e.g. coatings/liners for zirconium-based cladding) Reduce or eliminate hydrogen generation Increase resistance to bulk steam oxidation Achievement of our goals and objectives, as defined above, will lead to safer light-water reactor (LWR) nuclear fuel assemblies, due to improved cladding properties and built-in accident resistance, as well as

  8. Spatial mode-selective waveguide with hyperbolic cladding.

    Science.gov (United States)

    Tang, Y; Xi, Z; Xu, M; Bäumer, S; Adam, A J L; Urbach, H P

    2016-09-15

    Hyperbolic metamaterials (HMMs) are anisotropic materials with a permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as a cladding material, a waveguide that only supports higher-order modes can be achieved, while the lower-order modes become leaky and are absorbed in the HMM cladding. This counter-intuitive property can lead to novel application in optical communications and photonic integrated circuits. The loss in our HMM insulator-HMM (HIH) waveguide is smaller than that of similar guided modes in a metal-insulator-metal (MIM) waveguide.

  9. Method and system for edge cladding of laser gain media

    Science.gov (United States)

    Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene

    2014-03-25

    A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.

  10. Efficient microfluidic photocatalysis in a symmetrical metal-cladding waveguide.

    Science.gov (United States)

    Zhu, Shu; Dai, Hailang; Jiang, Bei; Shen, Zhenhua; Chen, Xianfeng

    2016-02-14

    In this paper, a symmetrical metal-cladding optical waveguide based microfluidic chip with a self-organized and free-standing TiO2 nanotube membrane was utilized to perform efficient photocatalysis. The chip has a microchannel bonded with TiO2 nanotube coated glass. The employment of microfluidic chip for hydrolysis reaction can enable the transfer of mass and photons. Moreover, the incorporation of the double metal-cladding waveguide enhances the light-matter interaction and effectively improves the efficiency of photocatalysis.

  11. A COMPREHENSIVE MODEL OF LASER CLADDING BY POWDER FEEDING

    Institute of Scientific and Technical Information of China (English)

    Y.L. Huang; G.Y. Liang; J.Y. Su

    2004-01-01

    A novel model was presented to predict the evolutionary development of cladding layer,and a method based on Lambert-Beer theorem and Mie's theory was adopted to treat the interaction between powder stream and laser beam. By using the continuum model and enthalpy-porosity method, the fluid flow and heat transfer in solid-liquid phase change system were simulated. The commercial software PHOENICS, to which several modules were appended, was used to accomplish the simulation. Numerical computation was performed for Stellite 6 cladding on steel, the obtained results are coincident with those measured in experiment basically.

  12. Spatial mode-selective waveguide with hyperbolic cladding

    Science.gov (United States)

    Tang, Y.; Xi, Z.; Xu, M.; Bäumer, S.; Adam, A. J. L.; Urbach, H. P.

    2016-09-01

    Hyperbolic Meta-Materials~(HMMs) are anisotropic materials with permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as cladding material, a waveguide which only supports higher order modes can be achieved, while the lower order modes become leaky and are absorbed in the HMM cladding. This counter intuitive property can lead to novel application in optical communication and photonic integrated circuit. The loss in our HMM-Insulator-HMM~(HIH) waveguide is smaller than that of similar guided mode in a Metal-Insulator-Metal~(MIM) waveguide.

  13. Characterization of Hydrogen Content in ZIRCALOY-4 Nuclear Fuel Cladding

    Science.gov (United States)

    Pfeif, E. A.; Lasseigne, A. N.; Krzywosz, K.; Mader, E. V.; Mishra, B.; Olson, D. L.

    2010-02-01

    Assessment of hydrogen uptake of underwater nuclear fuel clad and component materials will enable improved monitoring of fuel health. Zirconium alloys are used in nuclear reactors as fuel cladding, fuel channels, guide tubes and spacer grids, and are available for inspection in spent fuel pools. With increasing reactor exposure zirconium alloys experience hydrogen ingress due to neutron interactions and water-side corrosion that is not easily quantified without destructive hot cell examination. Contact and non-contact nondestructive techniques, using Seebeck coefficient measurements and low frequency impedance spectroscopy, to assess the hydrogen content and hydride formation within zircaloy 4 material that are submerged to simulate spent fuel pools are presented.

  14. Gradient microstructure in laser clad TiC-reinforced Ni-alloy composite coating

    NARCIS (Netherlands)

    Pei, Y.T.; Zuo, T.C.

    1998-01-01

    A gradient TiC–(Ni alloy) composite coating was produced by one step laser cladding with pre-placed mixture powder on a 1045 steel substrate. The clad layers consisted of TiC particles, γ-Ni primary dendrites and interdendritic eutectics. From the bottom to the top of the clad layer produced at 2000

  15. Aluminum, parathyroid hormone, and osteomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

    1983-01-01

    Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

  16. Novel accelerated corrosion test for LY12CZ and LC4CS aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    CAI Jian-ping; LIU Ming

    2006-01-01

    A new accelerated corrosion test-comprehensive environmental test (CET) was developed in order to estimate the outdoor corrosion of aluminum alloys in marine environment. The environmental characteristics in CET were studied by atmospheric corrosion monitor (ACM), and the morphology of corrosion product was observed by SEM. The correlation between the accelerated corrosion tests and outdoor exposure was discussed. The results show that the anti-corrosion ranking for LY12CZ, LC4CS, clad LY12CZ, and clad LC4CS in CET is the same as that of the alloys exposed outdoor, and ACM study shows that CET demonstrates the same environmental characteristics as that exposed outdoor. CET is a more accurate accelerated corrosion test, and a mathematical relation was obtained to describe the relation between CET and outdoor test.

  17. Microstructure and properties of the Ti/Al2O3/NiCr composites fabricated by explosive compaction/cladding.

    Science.gov (United States)

    Wang, Bingfeng; Xie, Fangyu; Wang, Bin; Luo, Xiaozhou

    2015-05-01

    Titanium/aluminum oxide/nickel chromium (Ti/Al2O3/NiCr) composite bar prepared by explosive compaction/cladding technique represents a new kind of sandwich-structural composites for medical application. Formation of the interfaces of Ti/Al2O3 and Al2O3/NiCr govern the properties of the composite material. The electrical resistivity and microstructure of the intermediate layer and the interfaces of the Ti/Al2O3/NiCr explosive compaction/cladding bar are investigated by means of four-point probe analysis, optical microscopy, scanning electron microscopy, electron microprobe analysis, and X-ray diffraction. The Ti/Al2O3/NiCr composite bar is characterized by the consolidated ceramic intermediate layer and the metallurgical bonding interfaces. The intermediate ceramic layer plays a role of insulation and thermal conductance in this composite. The average shear strength of the composite bar is about 9.36 MPa. The heat affected zone characterized by relatively larger sizes of grains is distinguished from the other part of the Ti tube. The intermetallics AlTi3 and Al0.9Ni4.22 are generated at the intermediate ceramic layer. Formation mechanism of the interfaces of the explosive compaction/cladding bar are described.

  18. Fabrication of aluminum foam from aluminum scrap Hamza

    Directory of Open Access Journals (Sweden)

    O. A. Osman1 ,

    2015-02-01

    Full Text Available In this study the optimum parameters affecting the preparation of aluminum foam from recycled aluminum were studied, these parameters are: temperature, CaCO3 to aluminum scrap wt. ratio as foaming agent, Al2O3 to aluminum scrap wt. ratio as thickening agent, and stirring time. The results show that, the optimum parameters are the temperature ranged from 800 to 850oC, CaCO3 to aluminum scrap wt. ratio was 5%, Al2O3 to aluminum scrap wt. ratio was 3% and stirring time was 45 second with stirring speed 1200 rpm. The produced foam apparent densities ranged from 0.40-0.60 g/cm3. The microstructure of aluminum foam was examined by using SEM, EDX and XRD, the results show that, the aluminum pores were uniformly distributed along the all matrices and the cell walls covered by thin oxide film.

  19. Wear resistance and hot corrosion behaviour of laser cladding Co-based alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    2Cr13 stainless steel was surface cladded with Co-based alloy using a high power carbon dioxide laser. The microstructure, wear resistance and corrosion properties of the clad layer were investigated. It is found that the high temperature corrosion behavior and wearing resistant property of the clad layer are 3 and 2.5 times higher than those of the parent metal. Under the high temperature molten lead sulphate salt corrosion condition, the clad layer fails by spalling which is caused by intergrannular corrosion within the clad layer. The fine dendritic structure and the oxide help to retard the penetration of the sulphur ion that induces the intergrannular corrosion.

  20. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating.

    Science.gov (United States)

    Yang, Tingting; Qiao, Xueguang; Rong, Qiangzhou; Bao, Weijia

    2016-09-11

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending dependence, together with a strong orientation dependence because of asymmetrical distribution of the "cladding" FBG along the fiber cross-section.

  1. A state of the Art report on Manufacturing technology of high burn-up fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Ho; Nam, Cheol; Baek, Jong Hyuk; Choi, Byung Kwon; Park, Sang Yoon; Lee, Myung Ho; Jeong, Yong Hwan

    1999-09-01

    In order to manufacturing the prototype fuel cladding, overall manufacturing processes and technologies should be thoroughly understood on the manufacturing processes and technologies of foreign cladding tubes. Generally, the important technology related to fuel cladding tube manufacturing processes for PWRs/PHWRs is divided into three stages. The first stage is to produce the zirconium sponge from zirconium sand, the second stage is to produce the zircaloy shell or TREX from zirconium sponge ingot and finally, cladding is produced from TREX or zircaloy shell. Therefore, the manufacturing processes including the first and second stages are described in brief in this technology report in order to understand the whole fuel cladding manufacturing processes. (author)

  2. 78 FR 7451 - Clad Steel Plate From Japan; Determination

    Science.gov (United States)

    2013-02-01

    ..., 2012 (77 FR 5052) and determined on May 7, 2012 that it would conduct a full review (77 FR 37439, June..., 2012 (77 FR 38825). The hearing was held in Washington, DC, on December 6, 2012, and all persons who... COMMISSION Clad Steel Plate From Japan; Determination On the basis of the record \\1\\ developed in the...

  3. Laser clad AlSiCuNi functionally graded coatings

    NARCIS (Netherlands)

    Pei, Yutao; de Hosson, J.T.M.; Brebbia, CA

    2001-01-01

    This paper presents an exploration of laser clad AlSiCuNi-alloy FGCs on cast Al-alloy substrates. SEM microstructure observations indicate that, besides Si primary particles, hard Al3Ni2 compounds also exhibits a continuous increase in both particle sizes and volume fractions from the bottom to the

  4. Elimination of Start/Stop defects in laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Eekma, M.; Hemmati, I.; De Hosson, J. Th. M.

    2012-01-01

    Laser cladding represents an advanced hard facing technology for the deposition of hard, corrosion and wear resistant layers of controlled thickness onto a selected area of metallic substrate. When a circular geometry is required, the beginning and the end of the laser track coincide in the same are

  5. Comments on ""Contact Diffusion Interaction of Materials with Cladding''

    Science.gov (United States)

    Morris, J. F.

    1972-01-01

    A Russian paper by A. A. Babad-Zakhryapina contributes much to the understanding of fuel, clad interactions, and thus to nuclear thermionic technology. In that publication the basic diffusion expression is a simple one. A more general but complicated equation for this mass transport results from the present work. With appropriate assumptions, however, the new relation reduces to Babad-Zakhryapina's version.

  6. Ultrahigh temperature-sensitive silicon MZI with titania cladding

    Directory of Open Access Journals (Sweden)

    Jong-Moo eLee

    2015-05-01

    Full Text Available We present a possibility of intensifying temperature sensitivity of a silicon Mach-Zehnder interferometer (MZI by using a highly negative thermo-optic property of titania (TiO2. Temperature sensitivity of an asymmetric silicon MZI with a titania cladding is experimentally measured from +18pm/C to -340 pm/C depending on design parameters of MZI.

  7. Direct Laser Cladding , Current Status and Future Scope of Application

    Science.gov (United States)

    Weisheit, A.; Gasser, A.; Backes, G.; Jambor, T.; Pirch, N.; Wissenbach, K.

    During the last decades Direct Laser Cladding has become an established technique in many industrial fields for applying wear and corrosion protection layers on metallic surfaces as well as for the repair of high value-added components. The most important application fields are die and tool making, turbine components for aero engines and power generation, machine components such as axes and gears, and oil drilling components. Continuous wave (CW) lasers with a power up to 18 kW are used on automated machines with three or more axes, enabling 3D cladding . The outstanding feature of DLC is the high precision which leads to a minimum heat input into the work piece and a very low distortion. Due to the high cooling rates a fine grained microstructure is achieved during solidification. A new development in laser cladding is micro cladding in a size range below 50 \\upmum especially for electronic and medical applications. Furthermore, additive manufacturing is coming again into focus as a clean and resource-efficient method to manufacture and modify functional prototypes as well as unique and small lot parts.

  8. Photonic crystal fiber with a hybrid honeycomb cladding

    DEFF Research Database (Denmark)

    Mortensen, Niels Asger; Nielsen, Martin Dybendal; Folkenberg, Jacob Riis;

    2004-01-01

    be formed by manipulating the cladding region ratherthan the core region itself. Germanium-doping of the honeycomb lattice has recently been suggested for the formation of a photonic band-gap guiding silica-core and here we experimentally demonstrate how an index-guiding silica-core can be formed...

  9. Characterisation of crack-like defects in the cladding

    Energy Technology Data Exchange (ETDEWEB)

    Tscharntke, D.; Tessaro, U.; Erhard, A. [Federal Inst. for Materials Research and Testing (BAM), Berlin (Germany); Schmitz, V. [Fraunhofer Inst. for Non-destructive Testing (IZFP), Saarbruecken (Germany); Mletzko, U. [Materials Testing Inst. of the Univ. of Stuttgart (MPA), Stuttgart (Germany)

    2004-07-01

    The results of a common research project of the Fraunhofer Institute for Nondestructive Testing (IZFP) in Saarbruecken, the Materials Testing Institute of the University of Stuttgart (MPA) and the Federal Institute for Materials Research and Testing (BAM) in Berlin are presented in the following. The measurements within the project shall give information about if and how characterisation of defects in the surface zone of cladded components is possible. On the basis of the measured data it should be possible to make a decision if the defect 1. is associated with the surface, 2. only lies in the cladding or in the base material, 3. extends from the cladding through to the base material. To achieve the project's aim measurements were carried out on different specimens, which are presented in conjunction with the following results. Thereby different inspection techniques and data interpretation algorithms were applied and the obtained results were compared. Inspection techniques employed include the impulse- echo- technique, the transmitter- receiver- technique and the time of flight diffraction technique (TOFD-technique). On some of the impulse- echo- measurements the synthetic- aperture- focussing- technique (SAFT) was applied. If possible the measurements were carried out on both sides of the specimens, that is coupling on the ferritic and on the cladded surface. Furthermore the influence of the angle of incidence, the direction of the weld process and the wave mode on the verifiability of the defects came also under investigation. This paper focuses on the results which were obtained at the BAM. (orig.)

  10. Crack resistance curves determination of tube cladding material

    Science.gov (United States)

    Bertsch, J.; Hoffelner, W.

    2006-06-01

    Zirconium based alloys have been in use as fuel cladding material in light water reactors since many years. As claddings change their mechanical properties during service, it is essential for the assessment of mechanical integrity to provide parameters for potential rupture behaviour. Usually, fracture mechanics parameters like the fracture toughness KIC or, for high plastic strains, the J-integral based elastic-plastic fracture toughness JIC are employed. In claddings with a very small wall thickness the determination of toughness needs the extension of the J-concept beyond limits of standards. In the paper a new method based on the traditional J approach is presented. Crack resistance curves (J-R curves) were created for unirradiated thin walled Zircaloy-4 and aluminium cladding tube pieces at room temperature using the single sample method. The procedure of creating sharp fatigue starter cracks with respect to optical recording was optimized. It is shown that the chosen test method is appropriate for the determination of complete J-R curves including the values J0.2 (J at 0.2 mm crack length), Jm (J corresponding to the maximum load) and the slope of the curve.

  11. Rebuilding of metal components with laser cladding forming

    Science.gov (United States)

    Song, Jianli; Deng, Qilin; Chen, Changyuan; Hu, Dejin; Li, Yongtang

    2006-09-01

    Laser cladding forming (LCF) is a novel powerful tool for the repairing of metal components. Rebuilding of V-grooves on medium carbon steel substrates has been carried out with laser cladding forming technique using stainless steel powder as the cladding material. Microstructure of the deposited layers has been characterized using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDAX), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Mechanical properties of the rebuilt V-groove samples have been evaluated by tensile and impacting tests and microhardness measurement. Experimental results show that good fusion bonding between the rebuilt layers and the substrate has been formed, and the microstructure of the cladding layers is mainly composed of fine, dense and defect-free epitaxial columnar dendrites. Due to the effect of grain size refinement, the tensile strength, impacting toughness, elongation and microhardness of the rebuilt samples have been greatly enhanced compared to those of the substrate. Microhardness is also very uniform throughout the rebuilt regions. With the growth of the deposited layers, the microhardness increases gradually. The good ductility of the deposited regions is verified by the SEM fracture analysis.

  12. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Pei, Y. T.; Ocelik, V.; De Hosson, J. T. M.

    2003-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-situ microstructural observations during straining in a field-emission

  13. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    De Hosson, JTM; Pei, YT; Ocelik, [No Value; Sudarshan, TS; Stiglich, JJ; Jeandin, M

    2002-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-sitit microstructural observations during straining in an FEG-ESEM (fi

  14. Optimization of Hydride Rim Formation in Unirradiated Zr 4 Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Hanson, Brady D.; MacFarlan, Paul J.

    2013-09-30

    The purpose of this work is to build on the results reported in the M2 milestone M2FT 13PN0805051, document number FCRD-USED-2013-000151 (Hanson, 2013). In that work, it was demonstrated that unirradiated samples of zircaloy-4 cladding could be pre-hydrided at temperatures below 400°C in pure hydrogen gas and that the growth of hydrides on the surface could be controlled by changing the surface condition of the samples and form a desired hydride rim on the outside diameter of the cladding. The work performed at Pacific Northwest National Laboratory since the issuing of the M2 milestone has focused its efforts to optimize the formation of a hydride rim on available zircaloy-4 cladding samples by controlling temperature variation and gas flow control during pre-hydriding treatments. Surface conditioning of the outside surface was also examined as a variable. The results of test indicate that much of the variability in the hydride thickness is due to temperature variation occurring in the furnaces as well as how hydrogen gas flows across the sample surface. Efforts to examine other alloys, gas concentrations, and different surface conditioning plan to be pursed in the next FY as more cladding samples become available

  15. THE INTERFACE OF TERNARY-BORIDE-BASED HARD CLADDING MATERIAL

    Institute of Scientific and Technical Information of China (English)

    Y.G. Wang; Z.Q. Li; D. Zhang

    2004-01-01

    The interfacial microstructure of ternary-boride-based hard cladding material (YF2) has been studied using scanning electron microanalyser (SEM), X-ray diffraction (XRD) and energy disperse spectroscopy (EDS). Results show that there are chemical reactions and elements diffusion in the interfacial zone, which make the interface bonding well and bonding strength ideal at the interface. The results gotten by studying of crack produced by Vickers indentation technique in the interfacial zone show that it is difficult to produce crack in the interface, the crack length in the cladding layer is longer than that to the interface, the crack which propagate to the interface stops at the interface rather than propagates along the interface. This suggests negligible residual stresses have developed because of thermal expansion mismatch. The bonding strength of the interface is 550MPa, which has been gotten by cutting test. The result gotten by analyzing the fracture surface shows that the fracture occurs at the side of cladding layer, which confirms that the bonding strength at the interface is higher than that in the cladding layer.

  16. 77 FR 31834 - Clad Steel Plate from Japan: Final Results of the Expedited Third Sunset Review of the...

    Science.gov (United States)

    2012-05-30

    ... layer of cladding material (usually stainless steel or nickel) which is metallurgically bonded to a base... weight. \\1\\ Cladding is the association of layers of metals of different colors or natures by molecular... cladding processes include pouring molten cladding metal onto the basic metal followed by rolling;...

  17. Air-clad fibers: pump absorption assisted by chaotic wave dynamics?

    CERN Document Server

    Mortensen, Niels Asger

    2007-01-01

    Wave chaos is a concept which has already proved its practical usefulness in design of double-clad fibers for cladding-pumped fiber lasers and fiber amplifiers. In general, classically chaotic geometries will favor strong pump absorption and we address the extent of chaotic wave dynamics in typical air-clad geometries. While air-clad structures supporting sup-wavelength convex air-glass interfaces (viewed from the high-index side) will promote chaotic dynamics we find guidance of regular whispering-gallery modes in air-clad structures resembling an overall cylindrical symmetry. Highly symmetric air-clad structures may thus suppress the pump-absorption efficiency eta below the ergodic scaling law eta proportional to Ac/Acl, where Ac and Acl are the areas of the rare-earth doped core and the cladding, respectively.

  18. Electrically conductive anodized aluminum coatings

    Science.gov (United States)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  19. China’s Aluminum Resources

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> The aluminum industry makes one of the keyindustries in China’s industrial and agriculturalmodernization and features a high degree ofrelevance with all industries.Of all the 124existing industries in China,113 use aluminum,representing an industrial relevance rate of91%.The consumption of aluminum is also ofhigh relevance with China’s GDP.

  20. Aluminum for Plasmonics

    Science.gov (United States)

    2014-01-01

    in plasmon-enhanced light harvesting,14 photocatalysis ,511 surface- enhanced spectroscopies,1216 optics-based sensing,1722 nonlinear optics,2326...optical response of Al nanoparticles has appeared inconsistent relative to calculated spectra, even forwell-characterized geometries. Some studies have...model- ing their optical response. These results pro- vide a method for estimating the metallic purity of aluminum nanoparticles directly from their

  1. Evaluation of Tritium Content and Release from Pressurized Water Reactor Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Sharon M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chattin, Marc Rhea [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giaquinto, Joseph [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    It is expected that tritium pretreatment will be required in future reprocessing plants to prevent the release of tritium to the environment (except for long-cooled fuels). To design and operate future reprocessing plants in a safe and environmentally compliant manner, the amount and form of tritium in the used nuclear fuel (UNF) must be understood and quantified. Tritium in light water reactor (LWR) fuel is dispersed between the fuel matrix and the fuel cladding, and some tritium may be in the plenum, probably as tritium labelled water (THO) or T2O. In a standard processing flowsheet, tritium management would be accomplished by treatment of liquid streams within the plant. Pretreating the fuel prior to dissolution to release the tritium into a single off-gas stream could simplify tritium management, so the removal of tritium in the liquid streams throughout the plant may not be required. The fraction of tritium remaining in the cladding may be reduced as a result of tritium pretreatment. Since Zircaloy® cladding makes up roughly 25% by mass of UNF in the United States, processes are being considered to reduce the volume of reprocessing waste for Zircaloy® clad fuel by recovering the zirconium from the cladding for reuse. These recycle processes could release the tritium in the cladding. For Zircaloy-clad fuels from light water reactors, the tritium produced from ternary fission and other sources is expected to be divided between the fuel, where it is generated, and the cladding. It has been previously documented that a fraction of the tritium produced in uranium oxide fuel from LWRs can migrate and become trapped in the cladding. Estimates of the percentage of tritium in the cladding typically range from 0–96%. There is relatively limited data on how the tritium content of the cladding varies with burnup and fuel history (temperature, power, etc.) and how pretreatment impacts its release. To gain a better understanding of how tritium in cladding

  2. Development and property evaluation of nuclear grade wrought FeCrAl fuel cladding for light water reactors

    Science.gov (United States)

    Yamamoto, Y.; Pint, B. A.; Terrani, K. A.; Field, K. G.; Yang, Y.; Snead, L. L.

    2015-12-01

    Development of nuclear grade, iron-based wrought FeCrAl alloys has been initiated for light water reactor (LWR) fuel cladding to serve as a substitute for zirconium-based alloys with enhanced accident tolerance. Ferritic alloys with sufficient chromium and aluminum additions can exhibit significantly improved oxidation kinetics in high-temperature steam environments when compared to zirconium-based alloys. In the first phase, a set of model FeCrAl alloys containing 10-20Cr, 3-5Al, and 0-0.12Y in weight percent, were prepared by conventional arc-melting and hot-working processes to explore the effect of composition on the properties of FeCrAlY alloys. It was found that the tensile properties were insensitive to the alloy compositions studied; however, the steam oxidation resistance strongly depended on both the chromium and the aluminum contents. The second phase development focused on strengthening Fe-13Cr-5Al with minor alloying additions of molybdenum, niobium, and silicon. Combined with an optimized thermo-mechanical treatment, a thermally stable microstructure was produced with improved tensile properties at temperatures up to 741 °C.

  3. Multiresponse Optimization of Laser Cladding Steel + VC Using Grey Relational Analysis in the Taguchi Method

    Science.gov (United States)

    Zhang, Zhe; Kovacevic, Radovan

    2016-07-01

    Laser cladding of metal matrix composite coatings (MMCs) has become an effective and economic method to improve the wear resistance of mechanical components. The clad quality characteristics such as clad height, carbide fraction, carbide dissolution, and matrix hardness in MMCs determine the wear resistance of the coatings. These clad quality characteristics are influenced greatly by the laser cladding processing parameters. In this study, American Iron and Steel Institute (AISI) 420 + 20% vanadium carbide (VC) was deposited on mild steel with a high powder direct diode laser. The Taguchi-based Grey relational method was used to optimize the laser cladding processing parameters (laser power, scanning speed, and powder feed rate) with the consideration of multiple clad characteristics related to wear resistance (clad height, carbide volume fraction, and Fe-matrix hardness). A Taguchi L9 orthogonal array was designed to study the effects of processing parameters on each response. The contribution and significance of each processing parameter on each clad characteristic were investigated by the analysis of variance (ANOVA). The Grey relational grade acquired from Grey relational analysis was used as the performance characteristic to obtain the optimal combination of processing parameters. Based on the optimal processing parameters, the phases and microstructure of the laser-cladded coating were characterized by using x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS).

  4. Core temperature in super-Gaussian pumped air-clad photonic crystal fiber lasers compared with double-clad fiber lasers

    Indian Academy of Sciences (India)

    P Elahi; H Nadgaran; F Kalantarifard

    2007-03-01

    In this paper we investigate the core temperature of air-clad photonic crystal fiber (PCF) lasers pumped by a super-Gaussian (SG) source of order four. The results are compared with conventional double-clad fiber (DCF) lasers pumped by the same super-Gaussian and by top-hat pump profiles.

  5. Clad — Automatic Differentiation Using Clang and LLVM

    Science.gov (United States)

    Vassilev, V.; Vassilev, M.; Penev, A.; Moneta, L.; Ilieva, V.

    2015-05-01

    Differentiation is ubiquitous in high energy physics, for instance in minimization algorithms and statistical analysis, in detector alignment and calibration, and in theory. Automatic differentiation (AD) avoids well-known limitations in round-offs and speed, which symbolic and numerical differentiation suffer from, by transforming the source code of functions. We will present how AD can be used to compute the gradient of multi-variate functions and functor objects. We will explain approaches to implement an AD tool. We will show how LLVM, Clang and Cling (ROOT's C++11 interpreter) simplifies creation of such a tool. We describe how the tool could be integrated within any framework. We will demonstrate a simple proof-of-concept prototype, called Clad, which is able to generate n-th order derivatives of C++ functions and other language constructs. We also demonstrate how Clad can offload laborious computations from the CPU using OpenCL.

  6. Cutoff-cladding waveguides: Subdiffraction guided modes near cutoff

    CERN Document Server

    Gan, C H

    2014-01-01

    We propose a class of waveguides operating near cutoff such that electromagnetic energy is mainly bound to the cladding rather than the dielectric core to achieve subdiffraction confinement of light. The cladding incorporates an alternating stack of thin films that exhibit uniaxial form birefringence with a high contrast between the effective principal dielectric constants. In contrast to conventional dielectric waveguides, the effective modal length for the fundamental mode of the proposed waveguide diverges at a much slower rate for core thicknesses less than a twentieth of the illumination wavelength, and is comparable to that attainable for plasmonic waveguides. The proposed waveguide can be exploited for important applications such as optoelectronic integration, and the fundamental mode exhibits a near-uniform spatial field distribution potentially allowing for position-independent spontaneous emission enhancement effects.

  7. Enhanced optical nonlinearities in air-cladding silicon pedestal waveguides

    CERN Document Server

    Zhang, Yaojing; Yao, Yifei; Tsang, Hon Ki

    2016-01-01

    The third-order optical nonlinearity in optical waveguides has found applications in optical switching, optical wavelength conversion, optical frequency comb generation, and ultrafast optical signal processing. The development of an integrated waveguide platform with a high nonlinearity is therefore important for nonlinear integrated photonics. Here, we report the observation of an enhancement in the nonlinearity of an air-cladding silicon pedestal waveguide. We observe enhanced nonlinear spectral broadening compared to a conventional silicon-on-insulator waveguide. At the center wavelength of 1555 nm, the nonlinear-index coefficient of air-cladding silicon pedestal waveguide is measured to be about 5% larger than that of a conventional silicon-on-insulator waveguide. We observe enhanced spectral broadening from self-phase modulation of an optical pulse in the pedestal waveguide. The interaction of light with the confined acoustic phonons in the pedestal structure gives rise to a larger nonlinear-index coeffi...

  8. Modeling of Zircaloy cladding degradation under repository conditions

    Energy Technology Data Exchange (ETDEWEB)

    Santanam, L.; Raghavan, S.; Chin, B.A. [Auburn Univ., AL (USA). Dept. of Materials Engineering; Shaw, H. [Lawrence Livermore National Lab., CA (USA)

    1989-07-01

    Two potential degradation mechanisms, creep and stress corrosion cracking, of Zircaloy cladding during repository storage of spent nuclear fuel have been investigated. The deformation and fracture map methodology has been used to predict maximum allowable initial storage temperatures to achieve a thousand year life without rupture as a function of spent-fuel history. A stress analysis of fuel rods has been performed. Stresses in the outer zirconium oxide layer and the inner Zircaloy tube have been predicted for typical internal pressurization, oxide layer thickness, volume expansion from formation of the oxide layer and thermal expansion coefficients of the cladding and oxide. Stress relaxation occurring in-reactor has also been taken into account. The calculations indicate that for the anticipated storage conditions investigated, the outer zirconium oxide layer is in a state of compression thus making it unlikely that stress corrosion cracking of the exterior surface will occur. 20 refs., 6 figs., 9 tabs.

  9. Retrospective dosimetry analyses of reactor vessel cladding samples

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, L. R.; Soderquist, C. Z. [Battelle Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Fero, A. H. [Westinghouse Electric Company, Cranberry Twp., PA 16066 (United States)

    2011-07-01

    Reactor pressure vessel cladding samples for Ringhals Units 3 and 4 in Sweden were analyzed using retrospective reactor dosimetry techniques. The objective was to provide the best estimates of the neutron fluence for comparison with neutron transport calculations. A total of 51 stainless steel samples consisting of chips weighing approximately 100 to 200 mg were removed from selected locations around the pressure vessel and were sent to Pacific Northwest National Laboratory for analysis. The samples were fully characterized and analyzed for radioactive isotopes, with special interest in the presence of Nb-93m. The RPV cladding retrospective dosimetry results will be combined with a re-evaluation of the surveillance capsule dosimetry and with ex-vessel neutron dosimetry results to form a comprehensive 3D comparison of measurements to calculations performed with 3D deterministic transport code. (authors)

  10. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Guoping [Univ. of Wisconsin, Madison, WI (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States)

    2013-12-19

    To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.

  11. Effect of nanoparticles on the structure and properties of an aluminum alloy poured into a mould with the use of a magnetohydrodynamic disk pump

    Science.gov (United States)

    Katsnelson, S. S.; Pozdnyakov, G. A.; Cherepanov, A. N.

    2015-09-01

    The influence of two nanomodifiers with different compositions during their homogenization in the AL7 aluminum melt and moulding on the properties of the modified aluminum alloy is studied. Experiments are performed with the use of a centrifugal conductive magnetohydrodynamic pump. The melt is poured into a graphite mould with three cylindrical channels 38 mm in diameter and 160 mm long, which are designed for a metal mass of 500 g. Two compositions are used as modifying agents: nano-scale particles of the aluminum nitride powder 40-100 nm in size and metallized carbon nanotubes smaller than 25 nm, which are clad with aluminum to improve wetting of their surface. The analysis of the structure of the experimental and reference samples shows that the use of modifiers leads to refinement of the grain structure of the cast metal. According to the Hall-Petch theory, this effect may result in improvement of mechanical characteristics of the cast metal.

  12. Failure Characteristic of Laser Cladding Samples on Repeated Impact

    Institute of Scientific and Technical Information of China (English)

    SHI Shi-hong; ZHENG Qi-guang; FU Ge-yan; ZHANG Jin-ping

    2004-01-01

    Using self-made impact fatigue test instruments and related analytic devices,the mechanical components with laser cladding layer have been attempted.It is found that,on repeated impact force,several failure modes of the components include the surface cracks,surface plastic deformation,corrosive pitting and coat collapse,etc.The paper reported the test method and initial analysis conclusions about the unique failure characteristics of the mechanical components on repeated impact load.

  13. Electrical Characterization of Silicon Cores from Glass-Cladded Fibres

    OpenAIRE

    Lapointe, Kyle

    2014-01-01

    Semiconductor core fibres represent an emerging technology with potential applications in many areas, including photovoltaics and optical transmission. Recent advances in fibre manufacturing techniques has allowed long, continuous silicon core fibres to be produced in commercial draw towers. The effect of the molten core fibre fabrication method on the electrical properties of silicon cores from glass-clad fibres have been studied. Fibres with core diameters ranging from 60 to 300 µm wer...

  14. Influence of curvature on the losses of doubly clad fibers.

    Science.gov (United States)

    Marcuse, D

    1982-12-01

    The loss increase of the HE(11) mode of a doubly clad (depressed-index) fiber due to constant curvature is considered. The calculations presented in this paper are based on a simplified theory. We find that for typical fibers the leakage loss of the HE(11) mode begins to increase significantly when the radius of curvature of the fiber axis reaches the 1-10-cm range.

  15. Ion irradiation testing of Improved Accident Tolerant Cladding Materials

    Energy Technology Data Exchange (ETDEWEB)

    Anderoglu, Osman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tesmer, Joseph R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maloy, Stuart A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-14

    This report summarizes the results of ion irradiations conducted on two FeCrAl alloys (named as ORNL A&B) for improving the accident tolerance of LWR nuclear fuel cladding. After irradiation with 1.5 MeV protons to ~0.5 to ~1 dpa and 300°C nanoindentations were performed on the cross-sections along the ion range. An increase in hardness was observed in both alloys. Microstructural analysis shows radiation induced defects.

  16. Final report on accident tolerant fuel performance analysis of APMT-Steel Clad/UO₂ fuel and APMT-Steel Clad/UN-U₃Si₅ fuel concepts

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Galloway, Jack D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-12

    In FY2014 our group completed and documented analysis of new Accident Tolerant Fuel (ATF) concepts using BISON. We have modeled the viability of moving from Zircaloy to stainless steel cladding in traditional light water reactors (LWRs). We have explored the reactivity penalty of this change using the MCNP-based burnup code Monteburns, while attempting to minimize this penalty by increasing the fuel pellet radius and decreasing the cladding thickness. Fuel performance simulations using BISON have also been performed to quantify changes to structural integrity resulting from thinner stainless steel claddings. We account for thermal and irradiation creep, fission gas swelling, thermal swelling and fuel relocation in the models for both Zircaloy and stainless steel claddings. Additional models that account for the lower oxidation stainless steel APMT are also invoked where available. Irradiation data for HT9 is used as a fallback in the absence of appropriate models. In this study the isotopic vectors within each natural element are varied to assess potential reactivity gains if advanced enrichment capabilities were levied towards cladding technologies. Recommendations on cladding thicknesses for a robust cladding as well as the constitutive components of a less penalizing composition are provided. In the first section (section 1-3), we present results accepted for publication in the 2014 TOPFUEL conference regarding the APMT/UO₂ ATF concept (J. Galloway & C. Unal, Accident Tolerant and Neutronically Favorable LWR Cladding, Proceedings of WRFPM 2014, Sendai, Japan, Paper No.1000050). Next we discuss our preliminary findings from the thermo-mechanical analysis of UN-U₃Si₅ fuel with APMT clad. In this analysis we used models developed from limited data that need to be updated when the irradiation data from ATF-1 test is available. Initial results indicate a swelling rate less than 1.5% is needed to prevent excessive clad stress.

  17. Microbial Biofilm Growth on Irradiated, Spent Nuclear Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    S.M. Frank

    2009-02-01

    A fundamental criticism regarding the potential for microbial influenced corrosion in spent nuclear fuel cladding or storage containers concerns whether the required microorganisms can, in fact, survive radiation fields inherent in these materials. This study was performed to unequivocally answer this critique by addressing the potential for biofilm formation, the precursor to microbial-influenced corrosion, in radiation fields representative of spent nuclear fuel storage environments. This study involved the formation of a microbial biofilm on irradiated spent nuclear fuel cladding within a hot cell environment. This was accomplished by introducing 22 species of bacteria, in nutrient-rich media, to test vessels containing irradiated cladding sections and that was then surrounded by radioactive source material. The overall dose rate exceeded 2 Gy/h gamma/beta radiation with the total dose received by some of the bacteria reaching 5 × 103 Gy. This study provides evidence for the formation of biofilms on spent-fuel materials, and the implication of microbial influenced corrosion in the storage and permanent deposition of spent nuclear fuel in repository environments.

  18. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices.

  19. Topological dependence of mechanical responses of solidification microstructures in aluminum brazed joints

    Institute of Scientific and Technical Information of China (English)

    GAO Feng(高峰); QIAN Yi-yu(钱乙余); D.P.Sekulic; MA Xin(马鑫); F.Yoshida

    2003-01-01

    The main objective is to provide an evidence of spatial dependence of mechanical responses of a heterogeneous aluminum brazed joint re-solidified clad,and to confirm a sufficient sensitivity of a nano-indentation--load curve method for identifying the dependence.Topological features of a network of solidification microstructures(αphase and eutectic),formed during quench in a brazing process of aluminum alloy,influence significantly dynamic mechanical responses of resulting heterogeneous material.Nano/micro indentation depth vs load characteristics of differing phases suggest a spatially sensitive mechanical response of a re-solidified fillet in the joint zone.Hence,a spatial distribution,pattern formations and other morphological characteristics of microstructures have a direct impact on an ultimate joint integrity.Topology-induced variations of indentation-load curves was presented.A hypothesis involving microstructures'spatial distribution vs mechanical response was formulated.

  20. PRESSURE-IMPULSE DIAGRAM OF MULTI-LAYERED ALUMINUM FOAM PANELS UNDER BLAST PRESSURE

    Directory of Open Access Journals (Sweden)

    CHANG-SU SHIM

    2013-06-01

    Full Text Available Anti-terror engineering has increasing demand in construction industry, but basis of design (BOD is normally not clear for designers. Hardening of structures has limitations when design loads are not defined. Sacrificial foam claddings are one of the most efficient methods to protect blast pressure. Aluminum foam can have designed yield strength according to relative density and mitigate the blast pressure below a target transmitted pressure. In this paper, multi-layered aluminum foam panels were proposed to enhance the pressure mitigation by increasing effective range of blast pressure. Through explicit finite element analyses, the performance of blast pressure mitigation by the multi-layered foams was evaluated. Pressure-impulse diagrams for the foam panels were developed from extensive analyses. Combination of low and high strength foams showed better applicability in wider range of blast pressure.

  1. Refractive index sensitivity enhancement of optical fiber cladding mode by depositing nanofilm via ALD technology.

    Science.gov (United States)

    Zhao, Ying; Pang, Fufei; Dong, Yanhua; Wen, Jianxiang; Chen, Zhenyi; Wang, Tingyun

    2013-11-04

    The atomic layer deposition (ALD) technology is introduced to enhance the sensitivity of optical fiber cladding mode to surrounding refractive index (SRI) variation. The highly uniform Al2O nanofilm was deposited around the double cladding fiber (DCF) which presents cladding mode resonant feature. With the high refractive index coating, the cladding mode resonant spectrum was tuned. And the sensitivity enhancement for SRI sensor was demonstrated. Through adjusting the deposition cycles, a maximum sensitivity of 723 nm/RIU was demonstrated in the DCF with 2500 deposition cycles at the SRI of 1.34. Based on the analysis of cladding modes reorganization, the cladding modes transition of the coated DCF was investigated theoretically. With the high performance nanofilm coating, the proposed SRI sensor is expected to have wide applications in chemical sensors and biosensors.

  2. Long-Period Fibre Grating Thin Film Sensors Based on Cladding Mode Coupling

    Institute of Scientific and Technical Information of China (English)

    XU Yan-Ping; GU Zheng-Tian; CHEN Jia-Bi

    2005-01-01

    @@ Based on a method of rigorous vector-field analysis, a numerical model of triple-clad long-period fibre grating is established. The vector components of the electric field for the HE11 cladding mode are plotted to study the field distribution of the cladding mode. The local intensity curves of the first six l = 1 cladding modes are also given. It is found that the low-order HE modes have a larger proportion of intensity localized in the core than the low-order EH modes, just like the double-clad LPFG. Further, the coupling constant between the core mode and the cladding mode is analysed. The results show that the coupling constant of the low-order HE increases monotonously when the mode number becomes larger, and it varies monotonously with the film thickness except for a certain specific region.

  3. An improved method for stripping cladding light in high power fiber lasers

    Science.gov (United States)

    Li, Tenglong; Wu, Juan; Sun, Yinghong; Wang, Yanshan; Ma, Yi

    2015-02-01

    In order to ensure the high power all-fiber laser reliability and excellent beam quality, it is necessary to strip the unwanted cladding light. The common method for stripping cladding light is to recoat the double cladding fiber with a high index gel, but localized heating and low thermal conductivity of the recoating gel are the prime factors limiting the power-handling capability of the cladding power stripper(CPS). An improved fabrication technique to manufacture the CPS is presented. Light stripping section of the fiber is fused with a transparent quartz tube, by applying different amount of etchant along the quartz tube, frosted surface is created and uniformly removal of the cladding light is achieved. The quartz tube is joined to water-cooled thermal enclosure tightly without the gel to avoid heat aggregation. The power-handling capability of the device is tested under 200W of cladding light, and attenuation of 20 dB is achieved.

  4. Enhanced ductility in round tensile bars produced by cladding a ductile ring

    Science.gov (United States)

    Chen, X. X.; Wu, P. D.; Embury, J. D.; Huang, Y.

    2010-03-01

    The effect of cladding a ductile ring on necking and fracture in round bars under tension is studied numerically using the finite element method based on the Gurson damage model. It is demonstrated that the cladding increases both the necking strain and the fracture strain. The effects of topological arrangement of cladding ring on necking and fracture are numerically investigated. It is indicated that while a topological arrangement of cladding has no noticeable effect on necking, it significantly influences the fracture strain. For a given volume fraction of cladding, the fracture strain could increase about 11% if the ductile ring is moved from the outmost to the innermost. It is also found that the subtle appearance of fracture surface due to cladding displays strong mesh sensitivity and may even be an artefact of the mesh.

  5. Development of the recovery technology for nickel superalloy blades of the aircraft engine by laser cladding

    Science.gov (United States)

    Bykovskiy, D. P.; Petrovskiy, V. N.; Polskiy, V. I.; Chirikov, S. N.; Dzhumaev, P. S.

    2016-09-01

    Development of cladding modes was performed with a superalloy nickel based powder on a flat substrate from material identical to compressor and turbine blades. Cross sections were made, and a visual inspection of the shape and the quality of the clad track as well as themetallographic analysis were performed. Microhardness of the deposition zone, chemical composition of the base, cladded metals, and the heat affected zone were determined.

  6. Optical Cladding Waveguides in Dielectric Crystals Produced by Femtosecond Laser Inscription

    Directory of Open Access Journals (Sweden)

    Chen Feng

    2013-11-01

    Full Text Available In this work, the recent progress of our research on optical cladding waveguides in dielectric crystals produced by femtosecond laser inscription has been overviewed. With different scales at cross sections, the cladding waveguides support guidance from single mode to highly multi-modes, and work for wavelength till mid-infrared regimes. Applications of the fabricated cladding structures as new integrated light sources are introduced.

  7. Effect of cladding procedures on mechanical properties of heat treated dissimilar joint

    Directory of Open Access Journals (Sweden)

    B. Mateša

    2012-10-01

    Full Text Available The specimens plated by different cladding procedures (hot rolling, submerged arc welding surfacing using strip electrode (SAW and explosion welding were heat treated by annealing (650 ºC through 2 hours. Charpy impact energy testing, as well as shear strength testing of clad joints were performed. Testing results indicated significance of cladding procedure and determined heat treatment infl uences on stated mechanical properties.

  8. A method for limitation of probability of accumulation of fuel elements claddings damage in WWER

    OpenAIRE

    Sergey N. Pelykh; Mark V. Nikolsky; S. D. Ryabchikov

    2014-01-01

    The aim is to reduce the probability of accumulation of fuel elements claddings damage by developing a method to control the properties of the fuel elements on stages of design and operation of WWER. An averaged over the fuel assembly WWER-1000 fuel element is considered. The probability of depressurization of fuel elements claddings is found. The ability to predict the reliability of claddings by controlling the factors that determine the properties of the fuel elements is proved. The expedi...

  9. Aluminum Carbothermic Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Marshall J.

    2005-03-31

    This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry

  10. Raman probes based on optically-poled double-clad fiber and coupler

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

    2012-01-01

    Two fiber Raman probes are presented, one based on an optically-poled double-clad fiber and the second based on an optically-poled double-clad fiber coupler respectively. Optical poling of the core of the fiber allows for the generation of enough 532nm light to perform Raman spectroscopy...... of a sample of dimethyl sulfoxide (DMSO), when illuminating the waveguide with 1064nm laser light. The Raman signal is collected in the inner cladding, from which it is retrieved with either a bulk dichroic mirror or a double-clad fiber coupler. The coupler allows for a substantial reduction of the fiber...

  11. CO2 laser-fabricated cladding light strippers for high-power fiber lasers and amplifiers.

    Science.gov (United States)

    Boyd, Keiron; Simakov, Nikita; Hemming, Alexander; Daniel, Jae; Swain, Robert; Mies, Eric; Rees, Simon; Andrew Clarkson, W; Haub, John

    2016-04-10

    We present and characterize a simple CO2 laser processing technique for the fabrication of compact all-glass optical fiber cladding light strippers. We investigate the cladding light loss as a function of radiation angle of incidence and demonstrate devices in a 400 μm diameter fiber with cladding losses of greater than 20 dB for a 7 cm device length. The core losses are also measured giving a loss of cladding light stripping of a 300 W laser diode with minimal heating of the fiber coating and packaging adhesives.

  12. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, W., E-mail: wyman.zhuang@dsto.defence.gov.au [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Liu, Q.; Djugum, R.; Sharp, P.K. [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Paradowska, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2232 (Australia)

    2014-11-30

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface.

  13. Formation quality optimization of laser hot wire cladding for repairing martensite precipitation hardening stainless steel

    Science.gov (United States)

    Wen, Peng; Feng, Zhenhua; Zheng, Shiqing

    2015-01-01

    Laser cladding is an advantaged repairing technology due to its low heat input and high flexibility. With preheating wire by resistance heat, laser hot wire cladding shows better process stability and higher deposition efficiency compared to laser cold wire/powder cladding. Multi-pass layer were cladded on the surface of martensite precipitation hardening stainless steel FV520B by fiber laser with ER410NiMo wire. Wire feed rate and preheat current were optimized to obtain stable wire transfer, which guaranteed good formation quality of single pass cladding. Response surface methodology (RSM) was used to optimize processing parameters and predict formation quality of multi-pass cladding. Laser power P, scanning speed Vs, wire feed rate Vf and overlap ratio η were selected as the input variables, while flatness ratio, dilution and incomplete fusion value as the responses. Optimal clad layer with flat surface, low dilution and no incomplete fusion was obtained by appropriately reducing Vf, and increasing P, Vs and η. No defect like pore or crack was found. The tensile strength and impact toughness of the clad layer is respectively 96% and 86% of those of the substrate. The clad layer showed nonuniform microstructure and was divided into quenched areas with coarse lath martensite and tempered areas with tempered martensite due to different thermal cycles in adjacent areas. The tempered areas showed similar hardness to the substrate.

  14. Review of experimental data for modelling LWR fuel cladding behaviour under loss of coolant accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park (Sweden)

    2007-02-15

    Extensive range of experiments has been conducted in the past to quantitatively identify and understand the behaviour of fuel rod under loss-of-coolant accident (LOCA) conditions in light water reactors (LWRs). The obtained experimental data provide the basis for the current emergency core cooling system acceptance criteria under LOCA conditions for LWRs. The results of recent experiments indicate that the cladding alloy composition and high burnup effects influence LOCA acceptance criteria margins. In this report, we review some past important and recent experimental results. We first discuss the background to acceptance criteria for LOCA, namely, clad embrittlement phenomenology, clad embrittlement criteria (limitations on maximum clad oxidation and peak clad temperature) and the experimental bases for the criteria. Two broad kinds of test have been carried out under LOCA conditions: (i) Separate effect tests to study clad oxidation, clad deformation and rupture, and zirconium alloy allotropic phase transition during LOCA. (ii) Integral LOCA tests, in which the entire LOCA sequence is simulated on a single rod or a multi-rod array in a fuel bundle, in laboratory or in a tests and results are discussed and empirical correlations deduced from these tests and quantitative models are conferred. In particular, the impact of niobium in zirconium base clad and hydrogen content of the clad on allotropic phase transformation during LOCA and also the burst stress are discussed. We review some recent LOCA integral test results with emphasis on thermal shock tests. Finally, suggestions for modelling and further evaluation of certain experimental results are made.

  15. Development of data base with mechanical properties of un- and pre-irradiated VVER cladding

    Energy Technology Data Exchange (ETDEWEB)

    Asmolov, V.; Yegorova, L.; Kaplar, E.; Lioutov, K. [Nuclear Safety Inst. of Russian Research Centre, Moscow (Russian Federation). Kurchatov Inst.; Smirnov, V.; Prokhorov, V.; Goryachev, A. [State Research Centre, Dimitrovgrad (Russian Federation). Research Inst. of Atomic Reactors

    1998-03-01

    Analysis of recent RIA test with PWR and VVER high burnup fuel, performed at CABRI, NSRR, IGR reactors has shown that the data base with mechanical properties of the preirradiated cladding is necessary to interpret the obtained results. During 1997 the corresponding cycle of investigations for VVER clad material was performed by specialists of NSI RRC KI and RIAR in cooperation with NRC (USA), IPSN (France) in two directions: measurements of mechanical properties of Zr-1%Nb preirradiated cladding versus temperature and strain rate; measurements of failure parameters for gas pressurized cladding tubes. Preliminary results of these investigations are presented in this paper.

  16. Microstructure and Abrasive Wear Performance of Ni-Wc Composite Microwave Clad

    Science.gov (United States)

    Bansal, Amit; Zafar, Sunny; Sharma, Apurbba Kumar

    2015-10-01

    In the present work, Ni-WC powder was deposited on mild steel substrate to develop clads through microwave hybrid heating technique. The cladding trials were carried out in an industrial microwave applicator at 1.1 kW for 540 s. The Ni-WC composite clads were characterized for microstructure and abrasive wear performance through combination of x-ray diffraction, electron and optical microscopy, microhardness, and wear tests. Phase analysis of the Ni-WC clad indicated the presence of stable carbides such as WC, W2C, Ni2W4C, and Fe6W6C. The microstructure study of the clad layer revealed the presence of a uniformly distributed interlocked WC-based reinforcement embedded in the Ni-based matrix. The average Vicker's microhardness in the clad layer was observed to be 1028 ± 90 HV, which was approximately three times the microhardness of the substrate. Abrasive wear resistance of the microwave clads was superior to the MS substrate. Abrasion was the main wear mechanism in the Ni-WC clads and the substrate samples. However, the presence of WC-based reinforcement in the composite clads reduced microcutting, resulting in enhanced wear resistance.

  17. Air-clad fibers: pump absorption assisted by chaotic wave dynamics?

    DEFF Research Database (Denmark)

    Mortensen, Niels Asger

    2007-01-01

    Wave chaos is a concept which has already proved its practical usefulness in design of double-clad fibers for cladding-pumped fiber lasers and fiber amplifiers. In general, classically chaotic geometries will favor strong pump absorption and we address the extent of chaotic wave dynamics in typical...... air-clad structures may thus suppress the pump-absorption efficiency η below the ergodic scaling law η∞ Ac/Acl, where Ac and Acl are the areas of the rare-earth doped core and the cladding, respectively....

  18. Dependence of bending losses on cladding thickness in plastic optical fibers.

    Science.gov (United States)

    Durana, Gaizka; Zubia, Joseba; Arrue, Jon; Aldabaldetreku, Gotzon; Mateo, Javier

    2003-02-20

    Our main goal is to provide a comprehensive explanation of the existing differences in bending losses arising from having step-index multimode plastic optical fibers with different cladding thickness and under different types of conditions, namely, the variable bend radius R, the number of fiber turns, or the fiber diameter. For this purpose, both experimental and numerical result of bending losses are presented for different cladding thicknesses and conditions. For the measurements, two cladding thicknesses have been considered: one finite and another infinite. A fiber in air has a finite cladding thickness, and rays are reflected at the cladding-air interface, whereas a fiber covered by oil is equivalent to having an infinite cladding, since the very similar refractive index of oil prevents reflections from occurring at the cladding-oil interface. For the sake of comparison, numerical simulations based on ray tracing have been performed for finite-cladding step-index multimode waveguides. The numerical results reinforce the experimental data, and both the experimental measurements and the computational simulations turn out to be very useful to explain the behavior of refracting and tunneling rays along bent multimode waveguides and along finite-cladding fibers.

  19. A vertical type twin roll caster for an aluminium alloy clad strip

    OpenAIRE

    T. Haga; Nakamura, R; Kuma, S; H. Watari

    2013-01-01

    Purpose: of this paper: Twin roll casters that can cast two layers and three layers clad strip of aluminium alloys were invented. One of the purposes of this paper is to report that the two layers and three layers clad strip could be cast by the twin roll caster of this study. The investigation of the characters of these casters and the clad strips was purpose of this paper, too. The connecting at the interface between the strips was most important in the casting of the clad strip. Therefore,...

  20. Impact of thicker cladding on the nuclear parameters of the NPP Krsko fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kromar, Marjan, E-mail: marjan.kromar@ijs.s [Jozef Stefan Institute, Reactor Physics Department, Jamova 39, 1001 Ljubljana (Slovenia); Kurincic, Bojan [Nuclear Power Plant Krsko, Engineering Division, Nuclear Fuel and Reactor Core, Vrbina 12, 8270 Krsko (Slovenia)

    2011-04-15

    To make fuel rods more resistant to grid-to-rod fretting or other cladding penetration failures, the cladding thickness could be increased or strengthened. Implementation of thicker fuel rod cladding was evaluated for the NPP Krsko that uses 16 x 16 fuel design. Cladding thickness of the Westinghouse standard fuel design (STD) and optimized fuel design (OFA) is increased. The reactivity effect during the fuel burnup is determined. To obtain a complete realistic view of the fuel behaviour a typical, near equilibrium, 18-month fuel cycle is investigated. The most important nuclear core parameters such as critical boron concentrations, isothermal temperature coefficient and rod worth are determined and compared.

  1. Laser assisted foaming of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kathuria, Y.P. [Laser X Co. Ltd., Aichi (Japan)

    2001-09-01

    Recently aluminum foams have evoked considerable interest as an alternative material owing to their wide range of applications ranging from microelectronics, through automobiles to aerospace industries. The manufacturing techniques and characterization methods for aluminum foams require further development to achieve effective and economical use of this material. In this communication the authors demonstrate the feasibility of unidirectional and localized expansion of the aluminum foam using the Nd-YAG/CO{sub 2} laser and powder metallurgy. (orig.)

  2. Thermocurrent dosimetry with high purity aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Fullerton, G.D.; Cameron, J.R.; Moran, P.R.

    1976-01-01

    The application of thermocurrent (TC) to ionizing radiation dosimetry was studied. It was shown that TC in alumina (Al/sub 2/O/sub 3/) has properties that are suited to personnel dosimetry and environmental monitoring. TC dosimeters were made from thin disks of alumina. Aluminum electrodes were evaporated on each side: on one face a high voltage electrode and on the opposite face a measuring electrode encircled by a guard ring. Exposure to ionizing radiation resulted in stored electrons and holes in metastable trapping sites. The signal was read-out by heating the dosimeter with a voltage source and picnometer connected in series between the opposite electrodes. The thermally remobilized charge caused a transient TC. The thermogram, TC versus time or temperature, is similar to a TL glow curve. Either the peak current or the integrated current is a measure of absorbed dose. Six grades of alumina were studied from a total of four commercial suppliers. All six materials displayed radiation induced TC signals. Sapphire of uv-grade quality from the Adolf Meller Co. (AM) had the best dosimetry properties of those investigated. Sources of interference were studied. Thermal fading, residual signal and radiation damage do not limit TC dosimetry. Ultraviolet light can induce a TC response but it is readily excluded with uv-opaque cladding. Improper surface preparation prior to electrode evaporation was shown to cause interference. A spurious TC signal resulted from polarization of surface contaminants. Spurious TC was reduced by improved cleaning prior to electrode application. Polished surfaces resulted in blocking electrodes and caused a sensitivity shift due to radiation induced thermally activated polarization. This was not observed with rough cut surfaces.

  3. Results of U-xMo (x=7, 10, 12 wt.%) Alloy versus Al-6061 Cladding Diffusion Couple Experiments Performed at 500, 550 and 600 Degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel Perez; Dennis D. Keiser, Jr.; Yongho Sohn

    2013-04-01

    The Reduced Enrichment for Research and Test Reactors (RERTR) program has been developing low enrichment fuel systems encased in Al 6061 for use in research and test reactors. U–Mo alloys in contact with Al and Al alloys can undergo diffusional interactions that can result in the development of interdiffusion zones with complex fine-grained microstructures composed of multiple phases. A monolithic fuel currently being developed by the RERTR program has local regions where the U–Mo fuel plate is in contact with the Al 6061 cladding and, as a result, the program finds information about interdiffusion zone development at high temperatures of interest. In this study, the microstructural development of diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo, and U-12wt.%Mo vs. Al 6061 (or 6061 aluminum) cladding, annealed at 500, 550, 600 degrees C for 1, 5, 20, 24, or 132 hours, was analyzed by backscatter electron microscopy and x-ray energy dispersive spectroscopy on a scanning electron microscope. Concentration profiles were determined by standardized wavelength dispersive spectroscopy and standardless x-ray energy dispersive spectroscopy. The results of this work shows that the presence of surface layers at the U–Mo/Al 6061 interface can dramatically impact the overall interdiffusion behavior in terms of rate of interaction and uniformity of the developed interdiffusion zones. It further reveals that relatively uniform interaction layers with higher Si concentrations can develop in U–Mo/Al 6061 couples annealed at shorter times and that longer times at temperature result in the development of more non-uniform interaction layers with more areas that are enriched in Al. At longer annealing times and relatively high temperatures, U–Mo/Al 6061 couples can exhibit more interaction compared to U–Mo/pure Al couples. The minor alloying constituents in Al 6061 cladding can result in the development of many complex phases in the interaction layer of U

  4. Corrosion behavior on aluminum alloy LY12 in simulated atmospheric corrosion process

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-yao; MA Teng; HAN Wei; YU Guo-cai

    2007-01-01

    The corrosion behavior of typical high-strength aluminum alloy LY12 was studied by accelerated corrosion tests of cyclic wet-dry-immersion containing media of NaHSO3 and NaCl to simulate the corrosion process in different atmosphere environment, and the corrosion mechanism was also discussed. The main experimental techniques include mass loss, morphological check, analysis of corrosion products and electrochemical measurement. The result shows that the mass loss of LY12, with or without cladding, has linear relationship with test time in the three kinds of chemical media, 0.02 mol/L NaHSO3, 0.006 mol/L NaCl and 0.02 mol/L NaHSO3+0.006 mol/L NaCl, respectively. A layer of cladding on high-strength aluminum alloy can raise evidently the resistance of atmospheric corrosion. Cl- can promote pitting generation on the oxide film of LY12 when HOS3- exists, LY12 can react much intensely with HOS3- derived from anions.

  5. Neurofibrillary pathology and aluminum in Alzheimer's disease

    OpenAIRE

    Shin, R. W.; Lee, V.M.Y.; Trojanowski, J.Q.

    1995-01-01

    Since the first reports of aluminum-induced neurofibrillary degeneration in experimental animals, extensive studies have been performed to clarify the role played by aluminum in the pathogenesis of Alzheimer's disease (AD). Additional evidence implicating aluminum in AD includes elevated levels of aluminum in the AD brain, epidemiological data linking aluminum exposure to AD, and interactions between aluminum and protein components in the pathological lesions o...

  6. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  7. Surface development of an aluminum brazing sheet during heating studied by XPEEM and XPS

    Science.gov (United States)

    Rullik, L.; Bertram, F.; Niu, Y. R.; Evertsson, J.; Stenqvist, T.; Zakharov, A. A.; Mikkelsen, A.; Lundgren, E.

    2016-10-01

    X-ray photoelectron emission microscopy (XPEEM) was used in combination with other microscopic and spectroscopic techniques to follow the surface development of an aluminum brazing sheet during heating. The studied aluminum alloy sheet is a composite material designed for vacuum brazing. Its surface is covered with a native aluminum oxide film. Changes in the chemical state of the alloying elements and the composition of the surface layer were detected during heating to the melting temperature. It was found that Mg segregates to the surface upon heating, and the measurements indicate the formation of magnesium aluminate. During the heating the aluminum oxide as well as the silicon is observed to disappear from the surface. Our measurements is in agreement with previous studies observing a break-up of the oxide and the outflow of the braze cladding onto the surface, a process assisted by the Mg segregation and reaction with surface oxygen. This study also demonstrates how XPEEM can be utilized to study complex industrial materials.

  8. Improved LWR Cladding Performance by EPD Surface Modification Technique

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael; Sridharan, Kumar

    2012-11-26

    This project will utilize the electro-phoretic deposition technique (EPD) in conjunction with nanofluids to deposit oxide coatings on prototypic zirconium alloy cladding surfaces. After demonstrating that this surface modification is reproducible and robust, the team will subject the modified surface to boiling and corrosion tests to characterize the improved nucleate boiling behavior and superior corrosion performance. The scope of work consists of the following three tasks: The first task will employ the EPD surface modification technique to coat the surface of a prototypic set of zirconium alloy cladding tube materials (e.g. Zircaloy and advanced alloys such as M5) with a micron-thick layer of zirconium oxide nanoparticles. The team will characterize the modified surface for uniformity using optical microscopy and scanning-electron microscopy, and for robustness using standard hardness measurements. After zirconium alloy cladding samples have been prepared and characterized using the EPD technique, the team will begin a set of boiling experiments to measure the heat transfer coefficient and critical heat flux (CHF) limit for each prepared sample and its control sample. This work will provide a relative comparison of the heat transfer performance for each alloy and the surface modification technique employed. As the boiling heat transfer experiments begin, the team will also begin corrosion tests for these zirconium alloy samples using a water corrosion test loop that can mimic light water reactor (LWR) operational environments. They will perform extended corrosion tests on the surface-modified zirconium alloy samples and control samples to examine the robustness of the modified surface, as well as the effect on surface oxidation

  9. Fabrication of a tantalum-clad tungsten target for LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.T., E-mail: atnelson@lanl.gov [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); O' Toole, J.A.; Valicenti, R.A. [Accelerator Operations and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Maloy, S.A. [Civilian Nuclear Program Office, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-12-15

    Development of a solid state bonding technique suitable to clad tungsten targets with tantalum was completed to improve operation of the Los Alamos Neutron Science Centers spallation target. Significant deterioration of conventional bare tungsten targets has historically resulted in transfer of tungsten into the cooling system through corrosion resulting in increased radioactivity outside the target and reduction of delivered neutron flux. The fabrication method chosen to join the tantalum cladding to the tungsten was hot isostatic pressing (HIP) given the geometry constraints of a cylindrical assembly and previous success demonstrated at KENS. Nominal HIP parameters of 1500 Degree-Sign C, 200 MPa, and 3 h were selected based upon previous work. Development of the process included significant surface engineering controls and characterization given tantalums propensity for oxide and carbide formation at high temperatures. In addition to rigorous acid cleaning implemented at each step of the fabrication process, a three layer tantalum foil gettering system was devised such that any free oxygen and carbon impurities contained in the argon gas within the HIP vessel was mitigated to the extent possible before coming into contact with the tantalum cladding. The result of the numerous controls and refined techniques was negligible coarsening of the native Ta{sub 2}O{sub 5} surface oxide, no measureable oxygen diffusion into the tantalum bulk, and no detectable carburization despite use of argon containing up to 5 ppm oxygen and up to 40 ppm total CO, CO{sub 2}, or organic contaminants. Post bond characterization of the interface revealed continuous bonding with a few microns of species interdiffusion.

  10. Fabrication of a tantalum-clad tungsten target for LANSCE

    Science.gov (United States)

    Nelson, A. T.; O'Toole, J. A.; Valicenti, R. A.; Maloy, S. A.

    2012-12-01

    Development of a solid state bonding technique suitable to clad tungsten targets with tantalum was completed to improve operation of the Los Alamos Neutron Science Centers spallation target. Significant deterioration of conventional bare tungsten targets has historically resulted in transfer of tungsten into the cooling system through corrosion resulting in increased radioactivity outside the target and reduction of delivered neutron flux. The fabrication method chosen to join the tantalum cladding to the tungsten was hot isostatic pressing (HIP) given the geometry constraints of a cylindrical assembly and previous success demonstrated at KENS. Nominal HIP parameters of 1500 °C, 200 MPa, and 3 h were selected based upon previous work. Development of the process included significant surface engineering controls and characterization given tantalums propensity for oxide and carbide formation at high temperatures. In addition to rigorous acid cleaning implemented at each step of the fabrication process, a three layer tantalum foil gettering system was devised such that any free oxygen and carbon impurities contained in the argon gas within the HIP vessel was mitigated to the extent possible before coming into contact with the tantalum cladding. The result of the numerous controls and refined techniques was negligible coarsening of the native Ta2O5 surface oxide, no measureable oxygen diffusion into the tantalum bulk, and no detectable carburization despite use of argon containing up to 5 ppm oxygen and up to 40 ppm total CO, CO2, or organic contaminants. Post bond characterization of the interface revealed continuous bonding with a few microns of species interdiffusion.

  11. 35CrMo steel surface by laser cladding Fe-based WC composite coating performance analysis

    Science.gov (United States)

    Zhou, Houming; Zhang, Haomin; Qin, Hengfeng

    2014-12-01

    The laser cladding technique in 35CrMo steel substrate prepared with different dosage under WC iron-based alloy cladding.Research the effects of different cladding WC addition on surface morphology, microstructure, microhardness and wear properties. The results show that 5% and 10% WC added amount of the surface quality of the cladding layer is preferably 15 % and 25 % of the volume of the WC surface of the cladding layer with varying degrees of cracks and pores, WC adding cladding layer can significantly improve the hardness. Through analysis we draw the conculation that,with 10% WC addition of iron-based alloy cladding the microhardness is 4.2 times the substrate , the relative wear resistance increased 4.1 than the substrate , enabling optimum cladding friction and wear properties.

  12. Ballistic Evaluation of 2060 Aluminum

    Science.gov (United States)

    2016-05-24

    experiments in Experimental Facilities (EFs) 108 and 106, as well as John Hogan of ARL/AMB, Hugh Walter of Bowhead Science and Technology, and David Handshoe...new aluminum (Al)-based monocoque armored-vehicle hulls such as those of the M2 Bradley Infantry Fighting Vehicles. Also in 2012 the Aluminum

  13. Pellet cladding interaction — Evaluation of lubrication by graphite

    Science.gov (United States)

    Wood, J. C.; Surette, B. A.; Aitchison, I.; Clendening, W. R.

    1980-01-01

    Graphite CANLUB interlayers between UO 2 pellets and Zircaloy cladding increase the tolerance of fuel pins to power ramping defects. This paper evaluates the effectiveness of graphite as a lubricant in dry, low oxygen potential environments such as exist at the UO 2 — Zircaloy interface of an operating fuel pin. Two types of laboratory tests were performed at 573 ± 5 K in moist air and also dry inert gas. In the first test series, graphite-coated Zircaloy cladding was expanded by the outward movement of a 4-segment bronze mandrel. Depleting the oxygen and water vapour reduced circumferential failure strains from about 19% to about 12%, but there remained a large margin of improvement over the 4% failure strain attained with bare Zircaloy. In the second series of laboratory tests a disc of UO 2 was clamped between Zircaloy plates, and the force required to cause it to slide was measured as a function of normal loading with and without graphite lubrication. The coefficient of friction μ for graphite lubricating a Zircaloy-UO 2 interface rose only slightly from 0.19 to 0.24 on changing the gaseous environment from laboratory air to dry deoxygenated helium. These values were low compared with μ ~ 0.9 for bare Zircaloy-UO 2 interfaces in air or inert gas. An indirect evaluation was made of whether or not graphite acts as a lubricant in-service by counting peripheral radial UO 2 cracks in metallographic cross-sections of irradiated fuel pins. The number of peripheral cracks in highly powered fuel depends on the interfacial shear stress at the pellet-clad interface, and hence on the friction coefficient. In fuel pins ramped to a linear power of 55 kW/m there were, on average, 17 peripheral UO 2 cracks in graphite lubricated CANLUB fuel compared with 30 in bare Zircaloy-clad fuel. We deduce that the ratio of friction coefficients in-service (CANLUB graphite : bare Zircaloy) had been 0.57 : 1.0. Finally, we discuss theoretical limitations of CAN-LUB coatings and their

  14. Widely tunable femtosecond solitonic radiation in photonic crystal fiber cladding

    DEFF Research Database (Denmark)

    Peng, J. H.; Sokolov, A. V.; Benabid, F.;

    2010-01-01

    We report on a means to generate tunable ultrashort optical pulses. We demonstrate that dispersive waves generated by solitons within the small-core features of a photonic crystal fiber cladding can be used to obtain femtosecond pulses tunable over an octave-wide spectral range. The generation...... process is highly efficient and occurs at the relatively low laser powers available from a simple Ti:sapphire laser oscillator. The described phenomenon is general and will play an important role in other systems where solitons are known to exist....

  15. Standard specification for architectural flat glass clad polycarbonate

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This specification covers the quality requirements for cut sizes of glass clad polycarbonate (GCP) for use in buildings as security, detention, hurricane/cyclic wind-resistant, and blast and ballistic-resistant glazing applications. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Wettability of Aluminum on Alumina

    Science.gov (United States)

    Bao, Sarina; Tang, Kai; Kvithyld, Anne; Tangstad, Merete; Engh, Thorvald Abel

    2011-12-01

    The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10-8 bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al2O3 system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al2O3 system increases with temperature.

  17. Oxidation resistant chromium coating on Zircaloy-4 for accident tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung-Hwan; Kim, Eui-Jung; Jung, Yang-Il; Park, Dong-Jun; Kim, Hyun-Gil; Park, Jeong-Yong; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The attributes of such a fuel are approved reaction kinetics with steam, a slower hydrogen generation rate, and good cladding thermo-mechanical properties. Many researchers have tried to modify zirconium alloys to improve their oxidation resistance in the early stages of the ATF development. Corrosion resistant coating on cladding is one of the candidate technologies to improve the oxidation resistance of zirconium cladding. By applying coating technology to zirconium cladding, it is easy to obtain corrosion resistance without a change in the base materials. Among the surface coating methods, arc ion plating (AIP) is a coating technology to improve the adhesion owing to good throwing power, and a dense deposit (Fig. 1). Owing to these advantages, AIP has been widely used to efficiently form protective coatings on cutting tools, dies, bearings, etc. In this study, The AIP technique for the protection of zirconium claddings from the oxidation in a high-temperature steam environment was studied. The homogeneous Cr film with a high adhesive ability to the cladding was deposited by AIP and acted as a protection layer to enhance the corrosion resistance of the zirconium cladding. It was concluded that the AIP technology is effective for coating a protective layer on claddings.

  18. Raman Spectroscopy Analysis of Oxide Film on Spent Fuel Rod Cladding from Qinshan PhaseⅠNPP

    Institute of Scientific and Technical Information of China (English)

    WANG; Hua-cai; TANG; Qi; FU; Cheng; LIANG; Zheng-qiang

    2015-01-01

    The outside surface of cladding is one of the important factors limiting the service life of the fuel rods.Studying the structure of oxide film under reactor operating conditions has great significance in study of the cause of different appearances of cladding,establishing the relationship between oxide film thickness and oxide structure

  19. Dielectric tube waveguides with absorptive cladding for broadband, low-dispersion and low loss THz guiding

    DEFF Research Database (Denmark)

    Bao, Hualong; Nielsen, Kristian; Bang, Ole;

    2015-01-01

    and dielectrics in this frequency range. Here we report on a novel twist on the classical tube waveguide where we deliberately introduce a thick and highly lossy cladding layer. By this we attenuate the field in the cladding and thus prevent interference with the core field. This mechanism breaks the well...

  20. Assessment of the Durability of Marble Cladding by Laboratory Exposure compared to Natural Exposure

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Leksø, Henrik; Grelk, Bent

    2003-01-01

    cladding panel exposed for the south facing natural climate during 29, 60 and 61 years, respectively, and a cladding panel of each of the marble types only exposed for indoor climate are cut in bars of size 30x30x300 mm. The bars from indoor are exposed to temperature cycles between 10 °C and 60 °C...

  1. Characteristics of WDM Couplers Based on 80 μm Cladding Fiber

    Institute of Scientific and Technical Information of China (English)

    Hyunsook; Shin; Woojin; Shin; Manjung; Han; Kyoungrok; Kim; Seungryong; Han; Yunsong; Jeong; K.; Oh

    2003-01-01

    We have fabricated 1310/1550 and 1480/1550nm WDM couplers using a fiber of 80μm cladding diameter, whose tapering length is shortened by 4~8mm for the identical coupling strength compared to those of 125μm cladding fibers. We also report their splicing loss to conventional single mode fibers.

  2. Thick metallic coatings produced by coaxial and side laser cladding : Processing and properties

    NARCIS (Netherlands)

    Ocelík, V.; De Hosson, J.T.M.

    2010-01-01

    Cobalt and iron-based, defect-free coatings with thicknesses from 1 to 3.3. mm were created by a laser cladding process on different steel substrates. Extensive laser cladding experiments with a gradual change of laser power were used to study relations between main processing parameters and geometr

  3. An electrochemical investigation of the corrosion behavior of aluminum alloys in chloride containing solutions; Investigacao eletroquimica da corrosao de ligas de aluminio em solucoes contendo cloretos

    Energy Technology Data Exchange (ETDEWEB)

    Campos Filho, Jorge Eustaquio de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica]. E-mail: jorgecamposfilho@yahoo.com.br; Neves, Celia de Figueiredo Cordeiro; Campos, Wagner Reis da Costa; Moreira, Marcilio Soares [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: caf@cdtn.br; wrcc@cdtn.br; msm@cdtn.br

    2005-07-01

    Aluminum alloys have been used as cladding materials for nuclear fuel in research reactors due to its corrosion resistance. Aluminum owes its good corrosion resistance to a protective barrier oxide film formed and strongly bonded to its surface. In pool type TRIGA IPR-R1 reactor, located at Centro de Desenvolvimento da Tecnologia Nuclear in Belo Horizonte, previous immersion coupon tests revealed that aluminum alloys suffer from pitting corrosion, in spite of high quality of water control. Corrosion attack is initiated by breaking the protective oxide film on aluminum alloy surface. Chloride ions can break this oxide film and stimulate metal dissolution. In this study the aluminum alloys 1050, 5052 and 6061 were used to evaluate their corrosion behavior in chloride containing solutions. The electrochemical techniques used were potentiodynamic anodic polarization and cyclic polarization. Results showed that aluminum alloys 5052 and 6061 present similar corrosion resistance in low chloride solutions (0,1 ppm NaCl) and in reactor water but both alloys are less resistant in high chloride solution (1 ppm NaCl). Aluminum alloy 1050 presented similar behavior in the three electrolytes used, regarding to pitting corrosion, indicating that the concentration of the chloride ions was not the only variable to influence its corrosion susceptibility. (author)

  4. Properties and features of structure formation CuCr-contact alloys in electron beam cladding

    Energy Technology Data Exchange (ETDEWEB)

    Durakov, Vasiliy G., E-mail: electron@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Dampilon, Bair V., E-mail: dampilon@ispms.tsc.ru, E-mail: gnusov@rambler.ru; Gnyusov, Sergey F., E-mail: dampilon@ispms.tsc.ru, E-mail: gnusov@rambler.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2014-11-14

    The microstructure and properties of the contact CuCr alloy produced by electron-beam cladding have been investigated. The effect of the electron beam cladding parameters and preheating temperature of the base metal on the structure and the properties of the coatings has been determined. The bimodal structure of the cladding coating has been established. The short circuit currents tests have been carried out according to the Weil-Dobke synthetic circuit simulating procedure developed for vacuum circuit breakers (VCB) test in real electric circuits. Test results have shown that the electron beam cladding (EBC) contact material has better breaking capacity than that of commercially fabricated sintered contact material. The application of the technology of electron beam cladding for production of contact material would significantly improve specific characteristics and reliability of vacuum switching equipment.

  5. Space-efficient fiber ribbon composed of reduced-cladding single-mode fibers

    Science.gov (United States)

    Chang, J. H.; Bae, S. H.; Kim, Hoon; Ouh, C. H.; Jung, C. H.; Cho, H. S.; Chung, Y. C.

    2016-09-01

    We develop a space-efficient single-mode fiber (SMF) having a cladding diameter of only 82 μm. This SMF has the depressed-cladding index profile and its mode-field diameter, cutoff wavelength, and macro bending loss are designed to be similar to those of the conventional step-index SMF. We fabricate this reduced-cladding SMF and measure its optical and mechanical characteristics. The results show that this fiber satisfies major specifications of the ITU-T G.654 recommendations. We also fabricate a fiber ribbon by using twelve of these reduced-cladding SMFs. Compared to a commercial fiber ribbon made of twelve standard SMFs having 125-μm cladding diameter, this fiber ribbon can improve the spatial efficiency by ∼75%.

  6. Wear resistance of laser cladding and plasma spray welding layer on stainless steel surface

    Institute of Scientific and Technical Information of China (English)

    Xinlin Wang(王新林); Shihong Shi(石世宏); Qiguang Zheng(郑启光)

    2004-01-01

    The effect of coatings, which are formed with laser cladding and plasma spray welding on 1Cr18Ni9Ti base metal, on wear resistance is studied, A 5-kW transverse flowing CO2 laser is used for cladding Co base alloy powder pre-placed on the substrate. Comparing with the plasma spray coatings, the spoiled rate of products with laser clad layers was lower and the rate of finished products was higher. Their microstructure is extremely fine. They have close texture and small size grain. Their dilution resulting from the compositions of the base metal and thermal effect on base metal are less. The hardness, toughness,and strength of the laser cladding layers are higher. Wear tests show that the laser layers have higher properties of anti-friction, anti-scour and high-temperature sliding strike. The wear resistance of laser clad layers are about one time higher than that of plasma spray welding layer.

  7. A large effective area multi-core fiber with an optimized cladding thickness.

    Science.gov (United States)

    Takenaga, Katsuhiro; Arakawa, Yoko; Sasaki, Yusuke; Tanigawa, Shoji; Matsuo, Shoichiro; Saitoh, Kunimasa; Koshiba, Masanori

    2011-12-12

    The cladding thickness of trench-assisted multi-core fibers was theoretically and experimentally investigated in terms of excess losses of outer cores. No significant micro-bending loss increase was observed on multi-core fibers with the cladding thickness of about 30 µm. The tolerance for the micro-bending loss of a multi-core fiber is larger than that of the single core fiber. However, the cladding thickness will be limited by the occurrence of the excess loss on outer cores. The reduction of cladding thickness is probably limited around 40 µm in terms of the excess loss. The multi-core fiber with an effective area of 110 µm(2) at 1.55 µm and 181-µm cladding diameter was realized without any excess loss.

  8. Microstructural and electrochemical characterization of laser deposited 18-10 austenitic stainless steel clad layers

    Energy Technology Data Exchange (ETDEWEB)

    Fouquet, F. (GEMPPM/CALFETMAT, 69 Villeurbanne (France)); Sallamand, P. (GEMPPM/CALFETMAT, 69 Villeurbanne (France)); Millet, J.P. (GEMPPM/CALFETMAT, 69 Villeurbanne (France) Physicochimie Industrielle, 69 Villeurbanne (France)); Frenk, A. (GEMPPM/CALFETMAT, 69 Villeurbanne (France) Centre de Traitement des Materiaux par Laser (CTML), Ecole Polytechnique Federale de Lausanne (Switzerland)); Wagniere, J.D. (GEMPPM/CALFETMAT, 69 Villeurbanne (France) Centre de Traitement des Materiaux par Laser (CTML), Ecole Polytechnique Federale de Lausanne (Switzerland))

    1993-11-01

    The present work reports on 18-10 stainless steel coatings produced by laser powder cladding technique on a mild steel. Uniform clad layers - about 600 [mu]m thick - have been produced through partially overlapping single cladding tracks. The clad layers thus obtained show excellent adherence, no cracks, few porosities and good chemical homogeneity. The microstructure is dendritic or cellular. Dentrites or cells have an austenitic structure and a small amount of [delta]-ferrite is detected in the interdendritic areas. The corrosion resistance of the clad layers is tested by electrochemical techniques in various neutral or acidified aqueous saline media, deaerated or naturally aerated. In every case, the coatings show an excellent uniform corrosion resistance. (orig.).

  9. The influence of hydride on fracture toughness of recrystallized Zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiao-Hung, E-mail: 175877@mail.csc.com.tw [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China); China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chiang, Ming-Feng [China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chen, Yen-Chen [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China)

    2014-04-01

    In this work, RXA cladding tubes were hydrogen-charged to target hydrogen content levels between 150 and 800 wppm (part per million by weight). The strings of zirconium hydrides observed in the cross sections are mostly oriented in the circumferential direction. The fracture toughness of hydrided RXA Zircaloy-4 cladding was measured to evaluate its hydride embrittlement susceptibility. With increasing hydrogen content, the fracture toughness of hydrided RXA cladding decreases at both 25 °C and 300 °C. Moreover, highly localized hydrides (forming a hydride rim) aggravate the degradation of the fracture properties of RXA Zircaloy-4 cladding at both 25 °C and 300 °C. Brittle features in the form of quasi-cleavages and secondary cracks were observed on the fracture surface of the hydride rim, even for RXA cladding tested at 300 °C.

  10. The Mechanical Response of Advanced Claddings during Proposed Reactivity Initiated Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cinbiz, Mahmut N [ORNL; Brown, Nicholas R [ORNL; Terrani, Kurt A [ORNL; Lowden, Rick R [ORNL; ERDMAN III, DONALD L [ORNL

    2017-01-01

    This study investigates the failure mechanisms of advanced nuclear fuel cladding of FeCrAl at high-strain rates, similar to design basis reactivity initiated accidents (RIA). During RIA, the nuclear fuel cladding was subjected to the plane-strain to equibiaxial tension strain states. To achieve those accident conditions, the samples were deformed by the expansion of high strength Inconel alloy tube under pre-specified pressure pulses as occurring RIA. The mechanical response of the advanced claddings was compared to that of hydrided zirconium-based nuclear fuel cladding alloy. The hoop strain evolution during pressure pulses were collected in situ; the permanent diametral strains of both accident tolerant fuel (ATF) claddings and the current nuclear fuel alloys were determined after rupture.

  11. Sensitivity analysis of a PWR fuel element using zircaloy and silicon carbide claddings

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Rochkhudson B. de; Cardoso, Fabiano; Salome, Jean A.D.; Pereira, Claubia; Fortini, Angela, E-mail: rochkhudson@ufmg.br, E-mail: claubia@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear

    2015-07-01

    The alloy composed of zirconium has been used effectively for over 50 years in claddings of nuclear fuel, especially for PWR type reactors. However, to increase fuel enrichment with the aim of raising the burning and maintaining the safety of nuclear plants is of great relevance the study of new materials that can replace safely and efficiently zircaloy cladding. Among several proposed material, silicon carbide (SiC) has a potential to replace zircaloy as fuel cladding material due to its high-temperature tolerance, chemical stability and low neutron affinity. In this paper, the goal is to expand the study with silicon carbide cladding, checking its behavior when submitted to an environment with boron, burnable poison rods, and temperature variations. Sensitivity calculation and the impact in multiplication factor to both claddings, zircaloy and silicon carbide, were performed during the burnup. The neutronic analysis was made using the SCALE 6.0 (Standardized Computer Analysis for Licensing Evaluation) code. (author)

  12. Introduction of an Innovative Cladding Panel System for Multi-Story Buildings

    Directory of Open Access Journals (Sweden)

    Hathairat Maneetes

    2014-08-01

    Full Text Available An Energy Dissipating Cladding System has been developed for use in buildings designed based on the concept of damage-controlled structure in seismic design. This innovative cladding panel system is capable of functioning both as a structural brace, as well as a source of energy dissipation, without demanding inelastic action and ductility from the basic lateral force resisting system. The structural systems of many modern buildings typically have large openings to accommodate glazing systems, and a popular type of construction uses spandrel precast cladding panels at each floor level that supports strip window systems. The present study focuses on developing spandrel type precast concrete cladding panels as supplementary energy dissipating devices that are added to the basic structural system. Through a series of analytical studies, the result of evaluating the ability of the proposed Energy Dissipating Cladding system to improve the earthquake resistance of the buildings is presented here.

  13. Laser cladding of Al + Ir powders on ZM5 magnesium base alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Laser cladding of preplaced Al + Ir powders on a ZM5 magnesium alloy was performed to enhance the corrosion resistance of the ZM5 magnesium alloy. A metallurgical bond was obtained at the coating/substrate interface. The corrosion potential (Ecorr) of the laser cladded sample was 169 mV positive to that of the untreated ZM5 substrate, while the corrosion current (Icorr) was some one order of magnitude lower. The laser cladded sample, unlike the untreated ZM5 substrate,showed a passive region in the polarization plot. Immersion tests confirmed that the corrosion resistance of the laser cladded ZM5 sample was significantly enhanced in 3.5 wt.% NaCl solution. The Al-rich phases of AlIr, Mg17Al12, and Al formed in the cladding layer and the rapid solid characteristics were contributed to the improved corrosion behavior of the coating.

  14. Hualu Aluminum Will Construct Large Coal-Power-Aluminum Aluminum Processing Industrial Chain

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The reporter learned from relevant departments of Baiyin City that in order to further push forward industrial upgrading,fulfill expansion and consolidation of the enterprise,Gansu Hualu Aluminum Co.,Ltd(Hualu Aluminum)will implement Out-Of-City-Into-Park project,

  15. 78 FR 3853 - Retrievability, Cladding Integrity and Safe Handling of Spent Fuel at an Independent Spent Fuel...

    Science.gov (United States)

    2013-01-17

    ... COMMISSION 10 CFR Parts 71 and 72 Retrievability, Cladding Integrity and Safe Handling of Spent Fuel at an... several key areas, such as: retrievability, cladding integrity, and safe handling of spent fuel... potential policy issues and requirements related to retrievability, cladding integrity, and safe handling...

  16. Microstructure and Tribological Properties of In Situ Synthesized TiN Reinforced Ni/Ti Alloy Clad Layer Prepared by Plasma Cladding Technique

    Science.gov (United States)

    Jin, Guo; Li, Yang; Cui, Huawei; Cui, Xiufang; Cai, Zhaobing

    2016-06-01

    A Ni/Ti composite coating enhanced by an in situ synthesized TiN phase was fabricated on FV520B steel by plasma cladding technology. The in situ formation of the TiN phase was confirmed by XRD, SEM, and TEM. The cladding layer consisted of three regions on going from the top to the bottom, namely, columnar grain regions, columnar dendritic regions, and fine grain regions. The cladding layer was composed of Ni3Ti, TiN, (Fe, Ni), and Ti phases. The dendritic and columnar regions were mainly composed of the Ni3Ti and (Fe, Ni) phases. The Ti phase was observed at the branches of dendrite crystals and columnar grains. The volume fraction of the TiN phase in the cladding layer was about 3.2%. The maximum micro-hardness value of the in situ formed coating (760 HV0.2) was higher than that of the pure coating (537 HV0.2). The cladding layer had a small amount of scratch and wear debris when a load of 20 N was used. As the test load increased, the wear debris in the cladding layer also increased and the massive furrows were not observed.

  17. Technical basis for storage of Zircaloy-clad spent fuel in inert gases

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Gilbert, E.R.

    1983-09-01

    This report summarizes the technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. In addition, dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor (PWR) fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved {similar_to}5,000 fuel rods, and {similar_to}600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570{sup 0}C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at {similar_to}70{sup 0}C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the United States. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380{sup 0}C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400{sup 0}C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved.

  18. Cladding and Structural Materials for Advanced Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Was, G S; Allen, T R; Ila, D; C,; Levi,; Morgan, D; Motta, A; Wang, L; Wirth, B

    2011-06-30

    The goal of this consortium is to address key materials issues in the most promising advanced reactor concepts that have yet to be resolved or that are beyond the existing experience base of dose or burnup. The research program consists of three major thrusts: 1) high-dose radiation stability of advanced fast reactor fuel cladding alloys, 2) irradiation creep at high temperature, and 3) innovative cladding concepts embodying functionally-graded barrier materials. This NERI-Consortium final report represents the collective efforts of a large number of individuals over a period of three and a half years and included 9 PIs, 4 scientists, 3 post-docs and 12 students from the seven participating institutions and 8 partners from 5 national laboratories and 3 industrial institutions (see table). University participants met semi-annually and participants and partners met annually for meetings lasting 2-3 days and designed to disseminate and discuss results, update partners, address outstanding issues and maintain focus and direction toward achieving the objectives of the program. The participants felt that this was a highly successful program to address broader issues that can only be done by the assembly of a range of talent and capabilities at a more substantial funding level than the traditional NERI or NEUP grant. As evidence of the success, this group, collectively, has published 20 articles in archival journals and made 57 presentations at international conferences on the results of this consortium.

  19. Novel Accident-Tolerant Fuel Meat and Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Robert D. Mariani; Pavel G Medvedev; Douglas L Porter; Steven L Hayes; James I. Cole; Xian-Ming Bai

    2013-09-01

    A novel accident-tolerant fuel meat and cladding are here proposed. The fuel meat design incorporates annular fuel with inserts and discs that are fabricated from a material having high thermal conductivity, for example niobium. The inserts are rods or tubes. Discs separate the fuel pellets. Using the BISON fuel performance code it was found that the peak fuel temperature can be lowered by more than 600 degrees C for one set of conditions with niobium metal as the thermal conductor. In addition to improved safety margin, several advantages are expected from the lower temperature such as decreased fission gas release and fuel cracking. Advantages and disadvantages are discussed. An enrichment of only 7.5% fully compensates the lost reactivity of the displaced UO2. Slightly higher enrichments, such as 9%, allow uprates and increased burnups to offset the initial costs for retooling. The design has applications for fast reactors and transuranic burning, which may accelerate its development. A zirconium silicide coating is also described for accident tolerant applications. A self-limiting degradation behavior for this coating is expected to produce a glassy, self-healing layer that becomes more protective at elevated temperature, with some similarities to MoSi2 and other silicides. Both the fuel and coating may benefit from the existing technology infrastructure and the associated wide expertise for a more rapid development in comparison to other, more novel fuels and cladding.

  20. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  1. Subsurface Aluminum Nitride Formation in Iron-Aluminum Alloys

    Science.gov (United States)

    Bott, June H.

    Transformation-induced plasticity (TRIP) steels containing higher amounts of aluminum than conventional steels are ideal for structural automotive parts due to their mechanical properties. However, the aluminum tends to react with any processing environment at high temperatures and therefore presents significant challenges during manufacturing. One such challenge occurs during secondary cooling, reheating, and hot-rolling and is caused by a reaction with nitrogen-rich atmospheres wherein subsurface aluminum nitride forms in addition to internal and external oxides. The nitrides are detrimental to mechanical properties and cause surface cracks. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron-aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectrometry, and transmission electron microscopy to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen-depleted region. By using model alloys and controlling the experimental atmosphere, this study is able to understand some of the more fundamental materials science behind aluminum nitride formation in aluminum-rich iron alloys and the relationship between internal nitride and oxide precipitation and external oxide scale morphology and composition. The iron-aluminum alloys were heated in N2 atmospheres containing oxygen impurities. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with a diffusion-based model. Increasing aluminum content to 3 and 5 wt% had the effects of modifying the surface-oxide scale composition and increasing its continuity

  2. Influence of processing parameters on microstructure and wear resistance of Ti+TiC laser clad layer on titanium alloy

    Institute of Scientific and Technical Information of China (English)

    WU Wan-liang; SUN Jian-feng; DONG Sheng-min; LIU Rongx-iang

    2006-01-01

    Laser cladding experiments were carried out on Ti-6Al-4V alloy with Ti+33%TiC(volume fraction) powders. Laser processing parameters were studied systematically to investigate the influences on the surface quality. Microstructure, microhardness and wear resistance of the clad layer were evaluated. The results show that the laser parameter has considerable influence on microstructure and wear resistance of laser clad layer. With the optimized technical parameters, a clad layer with good surface quality and uniform microstructure was obtained. The microhardness of the clad layer HV0.2 is 1 080, and the wear rate is reduced by 57 times.

  3. Orientation-dependent fiber-optic accelerometer based on grating inscription over fiber cladding.

    Science.gov (United States)

    Rong, Qiangzhou; Qiao, Xueguang; Guo, Tuan; Bao, Weijia; Su, Dan; Yang, Hangzhou

    2014-12-01

    An orientation-sensitive fiber-optic accelerometer based on grating inscription over fiber cladding has been demonstrated. The sensor probe comprises a compact structure in which a short section of thin-core fiber (TCF) stub containing a "cladding" fiber Bragg grating (FBG) is spliced to another single-mode fiber (SMF) without any lateral offset. A femtosecond laser side-illumination technique was utilized to ensure that the grating inscription remains close to the core-cladding interface of the TCF. The core mode and the cladding mode of the TCF are coupled at the core-mismatch junction, and two well-defined resonances in reflection appear from the downstream FBG, in which the cladding resonance exhibits a strong polarization and bending dependence due to the asymmetrical distribution of the cladding FBG along the fiber cross section. Strong orientation dependence of the vibration (acceleration) measurement has been achieved by power detection of the cladding resonance. Meanwhile, the unwanted power fluctuations and temperature perturbations can be referenced out by monitoring the fundamental core resonance.

  4. Early implementation of SiC cladding fuel performance models in BISON

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    SiC-based ceramic matrix composites (CMCs) [5–8] are being developed and evaluated internationally as potential LWR cladding options. These development activities include interests within both the DOE-NE LWR Sustainability (LWRS) Program and the DOE-NE Advanced Fuels Campaign. The LWRS Program considers SiC ceramic matrix composites (CMCs) as offering potentially revolutionary gains as a cladding material, with possible benefits including more efficient normal operating conditions and higher safety margins under accident conditions [9]. Within the Advanced Fuels Campaign, SiC-based composites are a candidate ATF cladding material that could achieve several goals, such as reducing the rates of heat and hydrogen generation due to lower cladding oxidation rates in HT steam [10]. This work focuses on the application of SiC cladding as an ATF cladding material in PWRs, but these work efforts also support the general development and assessment of SiC as an LWR cladding material in a much broader sense.

  5. Evaluation of Missing Pellet Surface Geometry on Cladding Stress Distribution and Magnitude

    Energy Technology Data Exchange (ETDEWEB)

    Capps, Nathan A.; Montgomery, Robert O.; Sunderland, Dion J.; Spencer, Ben; Pytel, Martin; Wirth, Brian D.

    2014-10-01

    Missing pellet surface (MPS) defects are local geometric defects that periodically occur in nuclear fuel pellets, usually as a result of the mishandling during the manufacturing process. The presences of these defects can lead to clad stress concentrations that are substantial enough to cause a through wall failure for certain conditions of power level, burnup, and power increase. Consequently, the impact of potential MPS defects has limited the rate of power increase or ramp rates in both PWR and BWR systems. Improved 3D MPS models that consider the effect of the MPS geometry can provide better understanding of the margins against PCMI clad failure. The Peregrine fuel performance code has been developed as a part the Consortium of Advanced Simulations of Light Water Reactors (CASL) to consider the inherently multi-physics and multi-dimensional mechanisms that control fuel behavior, including cladding failure by the presence of MPS defects. This paper presents an evaluation of the cladding stress concentrations as a function of MPS defect geometry. The results are the first step in a probabilistic approach to assess cladding failure during power maneuvers. This analysis provides insight into how varying pellet defect geometries affect the distribution of the cladding stress and fuel and cladding temperature and will be used to develop stress concentration factors for 2D and 3D models.

  6. Potential for fuel melting and cladding thermal failure during a PCM event in LWRs

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Croucher, D.W.

    1979-01-01

    The primary concern in nuclear reactor safety is to ensure that no conceivable accident, whether initiated by a failure of the reactor system or by incorrect operation, will lead to a dangerous release of radiation to the environment. A number of hypothesized off-normal power or cooling conditions, generally termed as power-cooling-mismatch (PCM) accidents, are considered in the safety analysis of light water reactors (LWRs). During a PCM accident, film boiling may occur at the cladding surface and cause a rapid temperature increase in the fuel and the cladding, perhaps producing embrittlement of the zircaloy cladding by oxidation. Molten fuel may be produced at the center of the pellets, extrude radially through open cracks in the outer, unmelted portion of the pellet and relocate in the fuel-cladding gap. If the amount of extruded molten fuel is sufficient to establish contact with the cladding, which is at a high temperature during film boiling, the zircaloy cladding may melt. The present work assesses the potential for central fuel melting and thermal failure of the zircaloy cladding due to melting upon being contacted by extruded molten UO/sub 2/-fuel during a PCM event.

  7. Characterization of Fe3Si-based coatings on low silicon steel by pulsed Nd:YAG laser cladding

    Institute of Scientific and Technical Information of China (English)

    Dan-yang Dong; Chang-sheng Liu; Sui-yuan Chen; Bin Zhang

    2009-01-01

    The Fe3Si based coating was produced on the Fe-lSi steel surface by a pulsed Nd:YAG (yttrium aluminum garnet) laser. Its phase constitution and microstructure were characterized by using X-ray diffraction (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM) with associated energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The hyperfine structure of the coating was studied by Mossbauer spectra (MS) and the magnetic property was also measured at room temperature by a vibrating sample magnetometer (VSM). The obtained coating is pore and crack-free with dense microstructure and high Si content. The metallurgical bonding between the coating and the substrate was realized. The micro-structure of the coating is typical fine dendrites. The major phase was confirmed by XRD and TEM to be the ordering DO3 structured Fe3Si phase. In addition, there were smaller amounts of the Fe5Si3 phase and the T-Fe phase in the coating. Compared with the sub-strate, the laser cladding coating has a lower saturation magnetization and a higher coercive force. The poor magnetic property might be because of rapid solidification microstructure and phase constitution in the coating.

  8. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  9. Design of erbium doped double clad ZBLAN Fibre laser

    Science.gov (United States)

    Oladeji, A.; Phillips, A.; Lamrini, S.; Scholle, K.; Fuhrberg, P.; Seddon, A. B.; Benson, T. M.; Sujecki, S.

    2015-06-01

    A high powered octagonal double clad ZBLAN (33 μm/330 μm, NA=0.13) glass fibre for mid-infrared light generation is studied using a one dimensional rate equation model. The fibre laser design employs the concept of cascade lasing and includes up-conversion phenomena. The results obtained demonstrate that efficient cascade lasing may be achieved in practice without the need for fibre grating fabrication, as a sufficient level of feedback for laser action is provided by Fresnel light reflection at ZBLAN glass fibre air interfaces. Further enhancement of the laser efficiency can be achieved by terminating one of the fibre ends with a mirror. Simulation results show that the laser operation with 20 W of pump power at 0.98 μm wavelength can be achieved at 2.75 μm operating wavelength with Er3+ ion concentrations of 60,000 ppm.

  10. Bioactivity of calcium phosphate bioceramic coating fabricated by laser cladding

    Science.gov (United States)

    Zhu, Yizhi; Liu, Qibin; Xu, Peng; Li, Long; Jiang, Haibing; Bai, Yang

    2016-05-01

    There were always strong expectations for suitable biomaterials used for bone regeneration. In this study, to improve the biocompatiblity of titanium alloy, calcium phosphate bioceramic coating was obtained by laser cladding technology. The microstructure, phases, bioactivity, cell differentiation, morphology and resorption lacunae were investigated by optical microscope (OM), x-ray diffraction (XRD), methyl thiazolyl tetrazolium (MTT) assay, tartrate-resistant acid phosphatase (TRAP) staining and scanning electronic microscope (SEM), respectively. The results show that bioceramic coating consists of three layers, which are a substrate, an alloyed layer and a ceramic layer. Bioactive phases of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) were found in ceramic coating. Osteoclast precursors have excellent proliferation on the bioceramic surface. The bioceramics coating could be digested by osteoclasts, which led to the resorption lacunae formed on its surface. It revealed that the gradient bioceramic coating has an excellent bioactivity.

  11. Evanescent light-matter Interactions in Atomic Cladding Wave Guides

    CERN Document Server

    Stern, Liron; Goykhman, Ilya; Levy, Uriel

    2012-01-01

    Alkali vapors, and in particular rubidium, are being used extensively in several important fields of research such as slow and stored light non-linear optics3 and quantum computation. Additionally, the technology of alkali vapors plays a major role in realizing myriad industrial applications including for example atomic clocks magentometers8 and optical frequency stabilization. Lately, there is a growing effort towards miniaturizing traditional centimeter-size alkali vapor cells. Owing to the significant reduction in device dimensions, light matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for non-linear interactions. Here, taking advantage of the mature Complimentary Metal-Oxide-Semiconductor (CMOS) compatible platform of silicon photonics, we construct an efficient and flexible platform for tailored light vapor interactions on a chip. Specifically, we demonstrate light matter interactions in an atomic cladding wave guide (ACWG), consisting of CMOS ...

  12. Pulsed Eddy Current Detecting for Ferromagnetic Specimen with a Cladding Layer%有包覆层铁磁试件的脉冲涡流检测

    Institute of Scientific and Technical Information of China (English)

    傅迎光; 王健; 孙明璇; 刘再斌; 范智勇; 石坤

    2013-01-01

    The extent of corrosion can be obtained by measuring the wall thicknesses of pressure vessels and pipes made of steel plates. When measuring the thicknesses of steel plates and other ferromagnetic materials by using pulsed eddy current technology, the cladding layer which consists of a protective layer and an insulat ing layer could affect the measurement results. In this paper, we mainly study this problem. According to the principle of pulsed eddy current detecting, using the finite element method, we simulated the thickness mea surement of the ferromagnetic specimen with cladding layer, and emphatically analyzed the effects of the clad ding layer on the measurement. The effects of the cladding layer on the measurement are related to the protec tive layer material, the specimen and insulating layer thickness. The effects of aluminum sheet on the mea surement range of the specimen thickness are larger than that of iron sheet. When using aluminum sheet as protective layer, we cannot measure the thickness if the specimen is less than 6 mm thickness. The smaller thickness of the specimen and insulating layer is, the smaller measurement error is. When the specimen thick ness is more than 10 mm, and insulating layer thickness is more than 50 mm, the effect of the cladding layer on the measurement can be neglected.%测量由钢板制作的压力容器和管道的壁厚,可以了解其腐蚀程度.用脉冲涡流检测钢板等铁磁材料的厚度时,由保护层和保温层构成的包覆层会对测厚结果产生影响.根据脉冲涡流检测的工作原理,使用有限元法,对有包覆层铁磁试件的厚度测量进行了仿真研究,重点分析了覆盖层对测量结果的影响.研究结果表明:包覆层对测量的影响与保护层材料、试件厚度和保温层厚度有关;对试件厚度测量范围的影响铝皮比铁皮保护层大,使用铝皮保护层时,不能测量厚度小于6 mm的试件;试件与保温层越厚,测量误

  13. Pulsed Eddy Current Detecting for Ferromagnetic Specimen with a Cladding Layer%有包覆层铁磁试件的脉冲涡流检测

    Institute of Scientific and Technical Information of China (English)

    傅迎光; 王健; 孙明璇; 刘再斌; 范智勇; 石坤

    2013-01-01

    By measuring the wall thicknesses of pressure vessels and pipes made of steel plates,one can determine their extent of corrosion.When the pulsed eddy current technology is used to measure the thicknesses of steel plates and other ferromagnetic materials,the cladding layer which consists of a protective layer and an insulating layer could affect the measurement results.In this paper,we mainly study this problem.According to the principle of pulsed eddy current detecting,using the finite element method,we simulated the thickness measurement of the ferromagnetic specimen with cladding layer,and emphatically analyzed the effects of the cladding layer on the measurement.The effects of the cladding layer on the measurement are related to the protective layer material,the specimen and insulating layer thickness.The effects of aluminum sheet on the measurement range of the specimen thickness are larger than those of iron sheet.When using aluminum sheet as protective layer,we cannot measure the thickness if the specimen is less than 6 mm thickness.The smaller thickness of the specimen and insulating layer is,the smaller measurement error is.When the specimen thickness is more than 10 mm,and insulating layer thickness is more than 50 mm,one can neglect effects of the cladding layer on the measurement.%测量由钢板制作的压力容器和管道的壁厚,可以了解其腐蚀程度.用脉冲涡流检测钢板等铁磁材料的厚度时,由保护层和保温层构成的包覆层,会对测厚结果产生影响.根据脉冲涡流检测的工作原理,使用有限元法,对有包覆层铁磁试件的厚度测量进行了仿真研究,重点分析了覆盖层对测量结果的影响.结果表明,包覆层对测量的影响与保护层材料、试件厚度和保温层厚度有关;对试件厚度测量范围的影响铝皮比铁皮保护层大,使用铝皮保护层时,不能测量厚度小于6mm的试件;试件与保温层越厚,测量误差越小,试件的厚度大于10 mm

  14. Air movement in a re-clad medium rise building and its effect on energy usage

    Energy Technology Data Exchange (ETDEWEB)

    Kula, H.G. [Lawrence Berkeley Lab., CA (United States). Energy Performance of Buildings; Ward, I.C. [Sheffield Univ. (United Kingdom). Dept. of Building Science

    1994-12-31

    This paper presents the results of a monitoring programme on a medium sized educational building which has had the external walls re-clad. The objective behind the re-cladding was to improve the durability of the building and to improve the thermal performance. The objectives of this work were to establish the viability of the calculation techniques used to simulate the ventilation, thermal and moisture performance of the re-cladding system. The results have shown that there is a good agreement between the methods currently being used and the actual performance. (author)

  15. Impact of core-cladding boundary shape on the waveguide properties of hollow core microstructured fibers

    Science.gov (United States)

    Pryamikov, A. D.; Alagashev, G. K.; Kosolapov, A. F.; Biriukov, A. S.

    2016-12-01

    In this paper we consider an interaction between the air core modes (ACMs) of hollow core waveguide microstructures and core-cladding boundary walls in various shapes. The analysis is based on well-established models such as the ARROW (anti-resonant reflecting optical waveguide) model and on the models proposed for the first time. In particular, we consider the dynamics of light localization in the polygonal core cladding boundary wall as dependant on the type of its discrete rotational symmetry. Based on our findings we analyze the mechanisms of light localization in the core-cladding boundary walls of negative curvature hollow core microstructured fibers (NC HCMFs).

  16. 10-W cladding-pumped fiber laser with single transverse mode output

    Institute of Scientific and Technical Information of China (English)

    Ping Yan(闰平); Mali Gong(巩马理); Pan Ou(欧攀); Wenlou Wei(韦文楼); Ruizhen Cui(崔瑞贞); Qiang Liu(柳强); Weipu Jia(贾维溥)

    2003-01-01

    A Yb-doped double-clad fiber laser is demonstrated with a measured power output of 10.6 W and a fundamental spatial mode. The optical-to-optical conversion efficiency is 44% and the slope efficiency is 86% closed to quantum efficiency of optical conversion. In our laser system, a D-shape (340 μm/400 μm) inner cladding Yb-doped fiber is used as the gain material within the Fabry-Perot cavity. Multimode diode pump radiation is injected into the cladding through an end facet of the composite fiber.

  17. Impact of core cladding boundary shape on the waveguide properties of hollow core microstructured fibers

    CERN Document Server

    Pryamikov, A D; Biriukov, A S

    2016-01-01

    In this paper we consider an interaction between the air core modes of hollow core waveguide microstructures and core cladding boundary walls in various shapes. The analysis is based on well established models such as the anti-resonant reflecting optical waveguide model and on the models proposed for the first time. In particular, we consider the dynamics of light localization in the polygonalcore cladding boundary wall as dependant on the type of its discrete rotational symmetry. Based on our findings we analyze the mechanisms of light localization in the core cladding boundary walls of negative curvature hollow core microstructured fibers.

  18. Yb3+-Doped Double-Clad Fibre Laser Based on Fibre Bragg Grating

    Institute of Scientific and Technical Information of China (English)

    范万德; 付圣贵; 张强; 宁鼎; 李丽君; 王志; 袁树忠; 董孝义

    2003-01-01

    A novel Yb3+-doped double-clad fibre laser based on a double-clad fibre Bragg grating is presented. The fibre Bragg grating, as the output mirror, has been formed in Yb3+-doped double-clad fibre with the phase-mask method. When the input pump power is 2.8 W, the maximum laser output power is 570mW, with < 0.2 nm in line-width at the wavelength of 1.058μm, over 40dB signal-to-noise ratio and 24% slope efficiency.

  19. Effect of MAE on the properties of phosphate edge-cladding glasses

    Institute of Scientific and Technical Information of China (English)

    Fenggang Zhao; Guonian Wang; Lili Hu

    2007-01-01

    Edge-cladding is a key factor in improving saturated small signal gain coefficient βs of large laser disc glass. In this paper, the glasses were melted with traditional method. The influences of mixed alkali effect (MAE) on refractive index, thermal expansion coefficient α, glass transition temperature Tg, dilatometer softening temperature Td, and relative chemical durability of phosphate edge-cladding glasses were studied.The results reveal that when Li/(Na + Li) = 0.5, Tg, Td, and dissolution rate (DR) reach a minimal value.These results are preferred in phosphate edge-cladding glasses.

  20. A large effective area multi-core fiber with an optimized cladding thickness

    OpenAIRE

    2011-01-01

    The cladding thickness of trench-assisted multi-core fibers was theoretically and experimentally investigated in terms of excess losses of outer cores. No significant micro-bending loss increase was observed on multi-core fibers with the cladding thickness of about 30 μm. The tolerance for the micro-bending loss of a multi-core fiber is larger than that of the single core fiber. However, the cladding thickness will be limited by the occurrence of the excess loss on outer cores. The reduction ...