Physico-chemical studies on samarium soaps in solid state

International Nuclear Information System (INIS)

Mehrotra, K.N.; Chauhan, M.; Shukla, R.K.

1989-01-01

The physico-chemical characteristics of samarium soaps (caproate and caprate) in solid state were investigated by IR, X-ray diffraction and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding and samarium soaps possess partial ionic character. The X-ray diffraction measurements were used to calculate the long spacings and the results confirmed the double layer structure of samarium soaps. The decomposition reaction was found kinetically of zero order and the values of energy of activation for the decomposition process for caproate and caprate were found to be 8,0 and 7,8 kcal mol -1 , respectively. (Authors)

The ion-exchange obtaining of high purity samarium oxide

International Nuclear Information System (INIS)

Brzyska, W.; Soltysiak, I.; Cygan, J.

1987-01-01

The use of lactic acid - EDTA mixture as an eluent for the obtaining of high purity samarium oxide was studied. The studies were carried out at room temperature on cation exchange resin Wofatit KPS X 8. The best results were obtained for lactic acid (0,26 mol/dm 3 ) - EDTA (0,013 mol/dm 3 ) mixture at pH 3,3. As the result of 57% samarium concentrate elution with column load 1:3 and flow rate 0,4 cm/min, over 99% pure samarium oxide with 73% yield has been obtained. The yield of spectrally pure Sm 2 O 3 exceeded 45%. (author)

Extraction of lanthanide elements and bismuth in molten lithium chloride-liquid bismuth-lithium alloy system

International Nuclear Information System (INIS)

Harada, Makoto; Adachi, Motonari; Kai, Yuichi; Koike, Kenichi

1987-01-01

The equilibrium distributions of neodymium and samarium between molten LiCl and liquid Bi-Li alloy were measured in a wide range of Li-mole fraction in the alloy phase, X Li . These lanthanide elements were extracted through redox reactions. In high X Li range, X Li > 0.03, the distributions of neodymium and bismuth in the salt phase increased markedly. The anomalous increase is attributed to the formation of the compound comprized of Nd, Li, Bi and oxygen in the salt phase. The reaction processes in samarium and neodymium were very fast and the extraction rates are controlled by the diffusion processes of the solutes and metallic lithium. (author)

Determination of 0.01–0.1% of samarium in 40–100 mg of lead chloride

NARCIS (Netherlands)

Agterdenbos, J.; Jütte, B.A.H.G.; Schuring, J.

1971-01-01

A method is described for the determination of 5–25 μg of samarium in about 40 mg of lead chloride, based on the removal of the lead by electrolysis and determination of the samarium by extraction with PAN and measurement of the extinction of the complex at 552 nm.

Implementation of an analytical technique for Samarium; Implementacion de una tecnica analitica para Samario

Energy Technology Data Exchange (ETDEWEB)

Garcia G, N. [ININ, Carretera Mexico-Toluca Km. 36.5, 52045 Estado de Mexico (Mexico)

2004-07-01

Since the Samarium presents the same chemical properties that the plutonium, it has been used as homologous in studies that allow us to know the behavior that the plutonium presents in solution, with the advantage of working with an inactive and not very dangerous element. At the moment studies of sorption of plutonium or samarium are made on some mineral matrices that present certain surface properties. Due to the low concentrations that are used in the studies of sorption of samarium on those reagent substrates, their detection becomes very difficult for the conventional analysis media. The luminescence is a technique that can detect lower concentrations, smaller at 1 X 10{sup -} {sup 2} M, but when fluorofors are used this limit of detection increases in several orders of magnitude. In this work it has been used the arsenazo-III as fluorofor agent since it reacts in a specific way with the samarium, forming a complex that presents a proportional luminescence to the concentration of the present samarium. The advantage of making the quantification of samarium by luminescence is that it can use the same instrumental equipment to determine the speciation of the samarium sipped in the zircon. (Author)

Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

International Nuclear Information System (INIS)

Castrillejo, Y.; Fernandez, P.; Medina, J.; Hernandez, P.; Barrado, E.

2011-01-01

This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) ↔ Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al 3 Sm and Al 2 Sm.

Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

Energy Technology Data Exchange (ETDEWEB)

Castrillejo, Y., E-mail: ycastril@qa.uva.es [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Fernandez, P. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Medina, J. [Dept Fisica Materia Condensada Cristalografia y Mineralogia, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Hernandez, P. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Carr. Pachuca-Tulancingo Km. 4.5, C.P. 42076 Pachuca, Hidalgo (Mexico); Barrado, E. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain)

2011-10-01

This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) {r_reversible} Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al{sub 3}Sm and Al{sub 2}Sm.

Samarium ion exchanged montmorillonite for high temperature cumene cracking reaction

International Nuclear Information System (INIS)

Binitha, N.N.

2009-01-01

Full text: Nano material Montmorillonite clay is cation exchanged with samarium and its catalytic influence in cumene cracking reaction is investigated. Effect of exchange with sodium ions on further exchange with samarium ions is also noted. Acidity measurements are done using TPD of ammonia. The retention of basic structure is proved from FTIR spectra and XRD patterns. Elemental analysis result shows that samarium exchange has occurred, which is responsible for the higher catalytic activity. Surface area and pore volume remains more or less unaffected upon exchange. Thermogravimetric analysis indicates the enhanced thermal stability on exchanging. Cumene cracking reaction is carried out at atmospheric pressure in a fixed bed glass reactor at 673 K. The predominance of Bronsted acidity is confirmed from high selectivity to benzene. (author)

Separation of lanthanum (3) and samarium (3) extraction with tributylphosphate in the solvent presence of solid phase

International Nuclear Information System (INIS)

Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.

1990-01-01

Lanthanum (3) and samarium (3) extraction from nitric acid solutions by tributylphosphate in the presence of solid phase has been investigated. An increase in samarium α-nitrate distribution factor in the presence of solid phase with a decrease in its concentration in the initial solution and with lanthanum nitrate concentration increase is detected. The greatest effect of separation is observed in samarium nitrate microregion. The method of quantitative extraction of samarium from lanthanum nitrate solutions with samarium-lanthanum separation factor exceeding 50 has been suggested

Biodistribution study of 153Sm-EDTMP produced by irradiation of natural and enriched Samarium, in rats

International Nuclear Information System (INIS)

Meftahi, M.; Bahrami Samani, A.; Babaei, M. H.; Shamsaei Zafarghandi, M.; Ghannadi Maragheh, M.

2010-01-01

''1 53 Sm-EDTMP is one of the well known radiopharmaceuticals for pain palliation of bone metastases. Despite that, it is used just in a few countries. It is due to some reasons like being costly enriched samarium that usually used as target for irradiation and short half-life of 153 Sm. In this investigation, certain amounts of radiopharmaceuticals prepared by irradiation of enriched and natural samarium were injected to some normal rats. Then, the rodents were sacrificed and some of their organs were removed. All of the mentioned stages were performed in order to consider the possibility of exploiting natural samarium instead of enriched samarium by study of biodistribution of both radiopharmaceuticals in various organs especially in bone as the target tissue. At the end, the acceptable results were obtained using natural samarium in comparison with the enriched samarium from the point of view of the biodistribution studies.

Influence of tellurite on lifetime for samarium doped lanthanum lead borate glass

Science.gov (United States)

Madhu, A.; Eraiah, B.

2018-04-01

Samarium substituted tellurium lanthanum lead borate glass is prepared using melt quenching technique. Luminescence spectra have been recorded upon excitation with 402 nm various transitions from 4G5/2 level, for samarium doped tellurite glasses are studied and also lifetime for all the samples exhibit single exponential behaviour of decay curve. Luminescence spectra of present glasses show quenching effect due to cross-relation channels of samarium ions. The lifetime of glass samples decrease as the tellurite concentration is decreased. So, it evidences that to attain longer lifetime for lasing material one can tune the host by selecting concentration of tellurite.

A NOVEL SAMARIUM COMPLEX WITH INTERESTING ...

African Journals Online (AJOL)

delocalized π-electrons of the pyridyl rings obtains increasing attention in ... BaSO4 plate was used as a reference (100% reflectance), on which the finely ground .... several are samarium-containing complex with bipy [41-45]. Figure 2.

Solubility isotherms in ternary systems of samarium nitrate, water and nitrates of amidopyrine, benzotriazole

International Nuclear Information System (INIS)

Starikova, L.I.

1991-01-01

Solubility in the system of samarium nitrate-amidopyrine nitrate-water at 25 and 50 deg C was studied. Solubility isotherms consist of three branches, corresponding to crystallization of samarium nitrate tetrahydrate, amidopyrine nitrate and congruently soluble compounds of Sm(NO 3 ) 3 · 2C 13 H 17 ON 3 ·HNO 3 composition. Its thermal behaviour was studied. The system of samarium nitrate-benzotriazole nitrate-water is referred to eutonic type

Basis for developing samarium AMS for fuel cycle analysis

International Nuclear Information System (INIS)

Buchholz, Bruce A.; Biegalski, Steven R.; Whitney, Scott M.; Tumey, Scott J.; Jordan Weaver, C.

2010-01-01

Modeling of nuclear reactor fuel burnup indicates that the production of samarium isotopes can vary significantly with reactor type and fuel cycle. The isotopic concentrations of 146 Sm, 149 Sm, and 151 Sm are potential signatures of fuel reprocessing, if analytical techniques can overcome the inherent challenges of lanthanide chemistry, isobaric interferences, and mass/charge interferences. We review the current limitations in measurement of the target samarium isotopes and describe potential approaches for developing Sm-AMS. AMS sample form and preparation chemistry will be discussed as well as possible spectrometer operating conditions.

4f and 5d magnetism in samarium

International Nuclear Information System (INIS)

Stunault, A.; Bernhoeft, N.; Vettier, C.; Dumesnil, K.; Dufour, C.

2001-01-01

We report on resonant magnetic X-ray scattering studies of a samarium epitaxial film at the samarium L 3 edge. We observe one quadrupolar resonance below the edge, reflecting the polarization of the 4f electrons, and two dipolar resonances above the edge, related to the polarization of the 5d band. We demonstrate, by following the thermal evolution of resonant magnetic intensities of both types, that the polarization of the 4f and 5d electrons present exactly the same temperature dependence, even very close to the ordering temperature, in agreement with the RKKY model for long-range magnetic order in rare earths

Studies on ultrasonic velocity and electrical conductivity of samarium soaps in non-aqueous medium

International Nuclear Information System (INIS)

Mehrotra, K.N.; Chauhan, M.; Shukla, R.K.

1990-01-01

The ultrasonic velocity of solutions of samarium soaps in non-aqueous medium has been measured at a constant temperature and the results have been used to evaluate the various acoustic parameters. The pre-micellar association and the formation of micelles in samarium soap solutions have been determined by conductometric measurements. The molar conductance at infinite dilution, degree of ionisation and ionisation constant have been evaluated. The results show that samarium soaps behave as weak electrolyte in dilute solutions. (Authors)

Nonlinear Faraday rotation in samarium vapor

International Nuclear Information System (INIS)

Barkov, L.M.; Melik-Pashaev, D.A.; Zolotorev, M.S.

1988-01-01

Experiments on nonlinear magnetic optical (Faraday) rotation on resonance transitions of atomic samarium are described. Measurements were carried out on transitions with different angular momenta of upper and lower states: 1→0, 0→1 and 1→1. Qualitative explanations of observed phenomena are given

Plasma sprayed samarium--cobalt permanent magnets

International Nuclear Information System (INIS)

Willson, M.C.; Janowiecki, R.J.

1975-01-01

Samarium--Co permanent magnets were fabricated by arc plasma spraying. This process involves the injection of relatively coarse powder particles into a high temperature gas for melting and spraying onto a substrate. The technique is being investigated as an economical method for fabricating Co--rare earth magnets for advanced traveling wave tubes and cross-field amplifiers. Plasma spraying permits deposition of material at high rates over large areas with optional direct bonding to the substrate, and offers the ability to fabricate magnets in a variety of shapes and sizes. Isotropic magnets were produced with high coercivity and good reproducibility in magnetic properties. Post-spray thermal treatments were used to enhance the magnetic properties of sprayed deposits. Samarium--Co magnets, sprayed from Sm-rich powder and subjected to post-spray heat treatment, displayed energy products in excess of 9 million G-Oe and coercive forces of approximately 6000 Oe. Bar magnet arrays were constructed by depositing magnets on ceramic substrates

Magnetoresistance of samarium in the 4.2-300 K range

International Nuclear Information System (INIS)

Trubitsyn, V.A.; Shalashov, V.F.

1980-01-01

Electric conductivity, transverse and longitudinal magnetoresistance of polycrystalline samarium with the purity of 99.9% in the 4.2-300 K temperature range and in magnetic fields up to 50 ke, are measured. The constituent of specific electric conductivity caused by spin disorder is 30.7 μOhmxcm, m*/m=2.6, the exchange parameter is G=3.1 eVxA 3 . Both transverse and longitudinal magnetoresistance are positive at 4.2 K; and the increase of temperature reveals a number of anomalies, evidently conditioned by the alteration of samarium magnetic structure

Synthesis of samarium complexes with the derivative binder of Schiff Quinolinic base. Characterization and photophysical study; Sintesis de complejos de samario con el ligante derivado de base de Schiff Quinolinica. Caracterizacion y estudio fotofisico

Energy Technology Data Exchange (ETDEWEB)

Lucas H, J.

2016-07-01

In this work we determined the metal: binder stoichiometry of the species formed during the UV/Vis spectrophotometric titration of the derivative binder of Schiff quinolinic base, L1 with the samarium nitrate pentahydrate in methanol. Statistical analysis of the data allowed proposing the metal: binder stoichiometry for the synthesis of the complexes which was one mole of samarium salt by 2.5 moles of binder and thus favor the formation of complexes with 1M: 1L and 1M: 2L stoichiometries. They were synthesized in aqueous-organic medium (water-ethanol), isolated and purified two complexes with stoichiometry 1 Sm: 1 L1, complex 1 and 1 Sm: 2 L1, complex 2. The overall yield of the reaction was 76%. The characterization of the formed complexes was performed by visible ultraviolet spectrometry (UV/Vis), nuclear magnetic resonance, X-ray photoelectron spectroscopy (XP S), thermal gravimetric analysis with differential scanning calorimetry (TGA/DSC), and radial distribution function. These complexes were studied by fluorescence and emission phosphorescence at variable temperature. Spectroscopic techniques used in both solution and solid demonstrated the formation and stability of these complexes. In addition XP S indicated that in both complexes the samarium retains its oxidation state 3+. Luminescence studies indicated that there is intra-binding charge transfer which decreases the transfer of light energy from the binder to the samarium. Based on the experimental results, L1 binder molecules and complexes 1 and 2 were modeled that demonstrated the proposed Nc for each complex, as well as allowed to visualize the structural arrangement of the molecules, complexes and binder. (Author)

Conductometric investigations on samarium soaps

International Nuclear Information System (INIS)

Mehrotra, K.N.; Chauhan, Mithlesh; Shukla, R.K.

1989-01-01

The critical micelle concentration (CMC), degree of dissociation and dissociation constant of samarium soaps (valerate, caproate, caprylate and caprate) in a mixture of 60 per cent benzene and 40 per cent methanol were determined by using conductometric measurements. The soaps behaved as simple electrolyte in dilute solutions and the CMC was found to decrease with increasing chainlength of the fatty acid constituent of the soap. (author). 7 refs., 2 tabs

Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

Science.gov (United States)

Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

2016-05-03

A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

Optical isotope shifts for unstable samarium isotopes

International Nuclear Information System (INIS)

Eastham, D.A.; Walker, P.M.; Griffith, J.A.R.; Evans, D.E.; Grant, I.S.; England, J.G.; Fawcett, M.J.

1984-01-01

Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144 Sm and 154 Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

The samarium Grignard reaction. In situ formation and reactions of primary and secondary alkylsamarium(III) reagents

Energy Technology Data Exchange (ETDEWEB)

Curran, D.P.; Totleben, M.J. [Univ. of Pittsburgh, PA (United States)

1992-07-15

This work shows that primary and secondary radicals are rapidly reduced in THF/HMPA to form primary- and secondary-alkylsamarium reagents. The primary- and secondary-radicals can be formed either by direct SmI{sup 2} reductions of primary- and secondary-halides or by a previous rapid radical cyclization. The samarium reagents have moderate stability in solution, and they react with a variety of typical electrophiles, including aldehydes and ketones. The work further shows that organosamarium intermediates can be involved in the traditional samarium Barbier reaction of aldehydes and ketones conducted in THF/HMPA. A new procedure called the {open_quotes}samarium Grignard{close_quotes} method is introduced, and it is suggested that this new procedure will have considerably more scope and generality than the samarium Barbier reaction. 37 refs., 4 tabs.

Fluorimetric determination of samarium(III) and europium(III) in neodymium oxide by separation with a resin column

Energy Technology Data Exchange (ETDEWEB)

Shaorong Liu; Jian Meng (Beijing Research Institute of Chemical Engineering and Metallurgy (China)); Wenhua Liu (General Research Institute for Non-Ferrous Metals (China))

1992-08-24

When thenoyltrifluoroacetone-phenanthroline-Triton X-100 is used to determine samarium(III) and europium(III) fluorimetrically, only a limited amount of neodymium(III) can be tolerated. By using an on- line separation which can partially separate neodymium(III) from samarium(III), a practical and convenient method was developed to detect samarium(III) at concentrations >0.05% and europium(III) at concentrations >0.005% in neodymium oxide. (author). 7 refs.; 4 figs.; 3 tabs.

Fluorimetric determination of samarium(III) and europium(III) in neodymium oxide by separation with a resin column

International Nuclear Information System (INIS)

Shaorong Liu; Jian Meng; Wenhua Liu

1992-01-01

When thenoyltrifluoroacetone-phenanthroline-Triton X-100 is used to determine samarium(III) and europium(III) fluorimetrically, only a limited amount of neodymium(III) can be tolerated. By using an on- line separation which can partially separate neodymium(III) from samarium(III), a practical and convenient method was developed to detect samarium(III) at concentrations >0.05% and europium(III) at concentrations >0.005% in neodymium oxide. (author). 7 refs.; 4 figs.; 3 tabs

Fabrication of a PVC membrane samarium(III) sensor based on N,N′,N″-tris(4-pyridyl)trimesic amide as a selectophore

International Nuclear Information System (INIS)

Zamani, Hassan Ali; Naghavi-Reyabbi, Fatemeh; Faridbod, Farnoush; Mohammadhosseini, Majid; Ganjali, Mohammad Reza; Tadjarodi, Azadeh; Rad, Maryam

2013-01-01

A new ion-selective electrode for Sm 3+ ion is described based on the incorporation of N,N′,N″-tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 ± 0.5 mV decade −1 over a wide concentration range of 1.0 × 10 −2 and 1 × 10 −6 mol L −1 , with a lower detection limit of 4.7 × 10 −7 mol L −1 and satisfactor applicable pH range of 3.6–9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm 3+ over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm 3+ . Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. - Highlights: ► A new Sm 3+ -PVC membrane sensor is introduced for determination of Sm 3+ ions in the solutions. ► N,N′,N″-tris(4-pyridyl)trimesic amide was used as a suitable selectophore for samarium sensor. ► Detection limit of the sensor is 4.7 × 10 −7 mol L −1 with a short response time of less than 10 s.

Alloying principles for magnesium base heat resisting alloys

International Nuclear Information System (INIS)

Drits, M.E.; Rokhlin, L.L.; Oreshkina, A.A.; Nikitina, N.I.

1982-01-01

Some binary systems of magnesium-base alloys in which solid solutions are formed, are considered for prospecting heat resistant alloys. It is shown that elements having essential solubility in solid magnesium strongly decreasing with temperature should be used for alloying maqnesium base alloys with high strength properties at increased temperatures. The strengthening phases in these alloys should comprise essential quantity of magnesium and be rather refractory

Adsorption and the initial stages of samarium condensation on iridium coated by graphite monolayer

International Nuclear Information System (INIS)

Abdullaev, R.M.; Tontegode, A.Ya.; Yusifov, F.K.

1978-01-01

Adsorption and the initial stages of vacuum samarium condensation on iridium coated by graphite monolayer (valent-saturated neutral substrate) were studied by the thermodesorption mass-spectrometry and thermoemission methods, and were compared with samarium adsorption and condensation on iridium. Desorption heat of samarium atoms with thin coating of Ir-C, equal to E approximately 1.9 eV has been determined. For desorption with Ir E is approximately 6 eV. Such a great difference in desorption heats is connected with the reduction of covalent constituent of adsorption bond in a neutral substrate. Samarium on Ir-C is found to be condensated in two states: loosely bound and tightly bound which sharply differ in properties. The tightly bound state is characterized by abnormally low vapour pressure. Possible nature of this state is discussed. Double effect on the condensation of the substrate valent saturation is noted. On the one hand, the reduction of the particle bond with the substrate decreases their concentration on the surface, preventing condensation. On the other hand, the release of the valent eloctrons of adatous brings about strong lateral interaction between them, which in its turn, promotes condensation during eased migration on the neutral substrate

Solar nebula heterogeneity in p-process samarium and neodymium isotopes.

Science.gov (United States)

Andreasen, Rasmus; Sharma, Mukul

2006-11-03

Bulk carbonaceous chondrites display a deficit of approximately 100 parts per million (ppm) in 144Sm with respect to other meteorites and terrestrial standards, leading to a decrease in their 142Nd/144Nd ratios by approximately 11 ppm. The data require that samarium and neodymium isotopes produced by the p process associated with photodisintegration reactions in supernovae were heterogeneously distributed in the solar nebula. Other samarium and neodymium isotopes produced by rapid neutron capture (r process) in supernovae and by slow neutron capture (s process) in red giants were homogeneously distributed. The supernovae sources supplying the p- and r-process nuclides to the solar nebula were thus disconnected or only weakly connected.

Solar Hydrogen Production via a Samarium Oxide-Based Thermochemical Water Splitting Cycle

Directory of Open Access Journals (Sweden)

Rahul Bhosale

2016-04-01

Full Text Available The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and water splitting steps are determined. The effect of oxygen partial pressure in the inert flushing gas on the thermal reduction temperature (TH is examined. An analysis based on the second law of thermodynamics is performed to determine the cycle efficiency (ηcycle and solar-to-fuel energy conversion efficiency (ηsolar−to−fuel attainable with and without heat recuperation. The results indicate that ηcycle and ηsolar−to−fuel both increase with decreasing TH, due to the reduction in oxygen partial pressure in the inert flushing gas. Furthermore, the recuperation of heat for the operation of the cycle significantly improves the solar reactor efficiency. For instance, in the case where TH = 2280 K, ηcycle = 24.4% and ηsolar−to−fuel = 29.5% (without heat recuperation, while ηcycle = 31.3% and ηsolar−to−fuel = 37.8% (with 40% heat recuperation.

Polypyrrole-coated samarium oxide nanobelts: fabrication, characterization, and application in supercapacitors

Science.gov (United States)

Liu, Peng; Wang, Yunjiao; Wang, Xue; Yang, Chao; Yi, Yanfeng

2012-11-01

Polypyrrole-coated samarium oxide nanobelts were synthesized by the in situ chemical oxidative surface polymerization technique based on the self-assembly of pyrrole on the surface of the amine-functionalized Sm2O3 nanobelts. The morphologies of the polypyrrole/samarium oxide (PPy/Sm2O3) nanocomposites were characterized using transmission electron microscope. The UV-vis absorbance of these samples was also investigated, and the remarkable enhancement was clearly observed. The electrochemical behaviors of the PPy/Sm2O3 composites were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge. The results indicated that the PPy/Sm2O3 composite electrode was fully reversible and achieved a very fast Faradaic reaction. After being corrected into the weight percentage of the PPy/Sm2O3 composite at a current density of 20 mA cm-2 in a 1.0 M NaNO3 electrolyte solution, a maximum discharge capacity of 771 F g-1 was achieved in a half-cell setup configuration for the PPy/Sm2O3 composites electrode with the potential application to electrode materials for electrochemical capacitors.

Silicon Alloying On Aluminium Based Alloy Surface

International Nuclear Information System (INIS)

Suryanto

2002-01-01

Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

Crystallization of Yttrium and Samarium Aluminosilicate Glasses

OpenAIRE

Lago, Diana Carolina; Prado, Miguel Oscar

2016-01-01

Aluminosilicate glasses containing samarium and yttrium (SmAS and YAS glasses) exhibit high glass transition temperatures, corrosion resistance, and glass stability on heating which make them useful for technological applications. Yttrium aluminosilicate glass microspheres are currently being used for internal selective radiotherapy of liver cancer. During the preparation process, crystallization needs to be totally or partially avoided depending on the final application. Thus knowing the cry...

Synthesis and structure of unprecedented samarium complex with bulky bis-iminopyrrolyl ligand via intramolecular C=N bond activation

Energy Technology Data Exchange (ETDEWEB)

Das, Suman; Anga, Srinivas; Harinath, Adimulam; Panda, Tarun K. [Department of Chemistry, Indian Institute of Technology, Hyderabad (India); Pada Nayek, Hari [Department of Applied Chemistry, Indian Institute of Technology, (ISM) Dhanbad, Jharkhand (India)

2017-12-29

An unprecedentate samarium complex of the molecular composition [{κ"3-{(Ph_2CH)N=CH}{sub 2}C{sub 4}H{sub 2}N}{κ"3-{(Ph_2CHN=CH)(Ph_2CHNCH)C_4H_2N}Sm}{sub 2}] (2), which was isolated by the reaction of a potassium salt of 2,5-bis{N-(diphenylmethyl)-iminomethyl}pyrrolyl ligand [K(THF){sub 2}{(Ph_2CH)N=CH}{sub 2}C{sub 4}H{sub 2}N] (1) with anhydrous samarium diiodide in THF at 60 C through the in situ reduction of imine bond is presented. The homoleptic samarium complex [[κ{sup 3}-{(Ph_2CH)-N=CH}{sub 2}C{sub 4}H{sub 2}N]{sub 3}Sm] (3) can also be obtained from the reaction of compound 1 with anhydrous samarium triiodide (SmI{sub 3}) in THF at 60 C. The molecular structures of complexes 2 and 3 were established by single-crystal X-ray diffraction analysis. The molecular structure of complex 2 reveals the formation of a C-C bond in the 2,5-bis{N-(diphenylmethyl)iminomethyl}pyrrole ligand moiety (Ph{sub 2}Py{sup -}). However, complex 3 is a homoleptic samarium complex of three bis-iminopyrrolyl ligands. In complex 2, the samarium ion adopts an octahedral arrangement, whereas in complex 3, a distorted three face-centered trigonal prismatic mode of nine coordination is observed around the metal ion. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Ultrasonic and viscosimetric studies of samarium laurate in benzene-dimethylsulfoxide mixtures

International Nuclear Information System (INIS)

Mehrotra, K.N.; Anis, M.

1995-01-01

Ultrasonic and viscosity measurements of samarium laurate in benzene-DMSO mixtures of different compositions (7:3 and 1:1 V/V) have been used to determine the critical micelle concentration (CMC), soap-solvent interaction, and various acoustic parameters of the system. The values of critical micelle concentration increase with increasing amount of DMSO in the solvent mixtures. The viscosity results have been explained on the basis of equations proposed by Einstein, Vand. Moulik, and Jones-Dole. The values of CMC for samarium laurate obtained from the viscosity measurements are in agreement with the results obtained from ultrasonic measurements. The results show that the soap molecules do not aggregate appreciably below CMC there is a marked change in the aggregation behaviour at CMC. (author)

Behavior of Samarium III during the sorption process; Comportamiento del Samario-III durante el proceso de sorcion

Energy Technology Data Exchange (ETDEWEB)

Ordonez R, E.; Garcia G, N.; Garcia R, G. [ININ, Carr. Mexico-Toluca Km 36.5, Salazar, Estado de Mexico (Mexico)]. e-mail: edo@nuclear.inin.mx

2004-07-01

In this work the results of the behavior of samarium in solution are presented, in front of a fine powder of zirconium silicate (zircon). For that which is necessary to characterize the zircon, studying the crystallinity, the morphology, the surface area and the isoelectric point. The behavior of samarium in solution is studied by means of the elaboration of isotherm of sorption, using the technique by lots. One observes that to pH values of nearer to the isoelectric point (pH = 7.23) the process of sorption of the samarium begins, reaching a maximum to near pH at 9. The technique of luminescence is used to determine the concentration of the sipped samarium (phosphorescence) and also to make the speciation of the species formed in the surface of the zircon (phosphorescence). The results can be extrapolated with the plutonium when making the modeling of the migration of alpha emitting coming from the repositories of radioactive waste since both they have similar chemical properties (they are homologous). (Author)

Inductively coupled plasma optical emission spectrometry analysis of lanthanum, samarium and gadolinium oxides for rare earths impurities

International Nuclear Information System (INIS)

Reino, L.C.P.; Lordello, A.R.

1990-09-01

An inductively coupled plasma optical emission spectrometry method is described for the determination of Sm, Eu, La, Gd, Dy, Pr, Ho, Nd, Tb and Y in purified oxides of lanthanum, samarium and gadolinium. The method enables a simple, precise and readily available determination. Dissolution of the samples is achieved with diluted hydrochloric acid (1:1). The solutions are diluted to volume for a concentration of 1mg/ml. The lowest determination limit is 0,01% for most elements and 0,05 or 0,1% for a few rare earths in samarium and gadolinium matrices. Lanthanum, Samarium and Gadolinium concentrates with purity grade of 99,9%, 99,6% and 99,8%, respectively, can be analysed by this procedure. (author)

Peculiarities of electronic, phonon and magnon subsystems of lanthanum and samarium tetraborides

Energy Technology Data Exchange (ETDEWEB)

Novikov, V.V., E-mail: vvnovikov@mail.ru; Mitroshenkov, N.V.; Matovnikov, A.V.

2015-10-15

Experimental research was carried out to study the temperature dependences of heat capacity C{sub p}(T = 2–300 K), lattice parameters a(T), and ≿(T), (5–300 K) of lanthanum and samarium tetraborides. A comparison with data obtained previously for LuB{sub 4} reveals the peculiar influence of lanthanide contraction and the rare-earths mass on the thermodynamic properties of rare earth tetraborides at low and high temperatures. Sharp anomalies were found in the heat capacity and thermal expansion for SmB{sub 4} at T{sub N} = 25.1 K, conditioned by the phase transition into antiferromagnetic state. The more poorly defined heat capacity anomaly around 7 K is referred to the quadrupole orbital fluctuation of the atomic magnetic moments for Sm{sup 3+} ions. The electronic, lattice, and magnetic contributions to the heat capacity and thermal expansion of samarium tetraboride were defined. Our approach makes it possible to adequately approximate the lattice components of heat capacity and thermal expansion by combining the Debye and Einstein contributions, which are based on the joint analysis of calorimetric and X-ray data. The influence of the frustration of the atomic magnetic moment system for Sm{sup 3+} ions on the thermodynamic characteristics of the samarium tetraboride magnetic phase transition was revealed. - Highlights: • The heat capacity and lattice parameters for LaB{sub 4} and SmB{sub 4} were determined at 2–300 K. • The anomalies of C{sub p}(T), a(T), c(T) for SmB{sub 4} due to the phase transition are revealed. • The lattice contributions to the thermal properties of LaB{sub 4} and SmB{sub 4} are analyzed.

Polypyrrole-coated samarium oxide nanobelts: fabrication, characterization, and application in supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Liu Peng, E-mail: pliu@lzu.edu.cn; Wang Yunjiao; Wang Xue; Yang Chao; Yi Yanfeng [College of Chemistry and Chemical Engineering, Lanzhou University, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry (China)

2012-11-15

Polypyrrole-coated samarium oxide nanobelts were synthesized by the in situ chemical oxidative surface polymerization technique based on the self-assembly of pyrrole on the surface of the amine-functionalized Sm{sub 2}O{sub 3} nanobelts. The morphologies of the polypyrrole/samarium oxide (PPy/Sm{sub 2}O{sub 3}) nanocomposites were characterized using transmission electron microscope. The UV-vis absorbance of these samples was also investigated, and the remarkable enhancement was clearly observed. The electrochemical behaviors of the PPy/Sm{sub 2}O{sub 3} composites were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge. The results indicated that the PPy/Sm{sub 2}O{sub 3} composite electrode was fully reversible and achieved a very fast Faradaic reaction. After being corrected into the weight percentage of the PPy/Sm{sub 2}O{sub 3} composite at a current density of 20 mA cm{sup -2} in a 1.0 M NaNO{sub 3} electrolyte solution, a maximum discharge capacity of 771 F g{sup -1} was achieved in a half-cell setup configuration for the PPy/Sm{sub 2}O{sub 3} composites electrode with the potential application to electrode materials for electrochemical capacitors.

Pemisahan Unsur Samarium dan Yttrium dari Mineral Tanah Jarang dengan Teknik Membran Cair Berpendukung (Supported Liquid Membrane

Directory of Open Access Journals (Sweden)

Amri Amin

2009-06-01

Full Text Available he increasing use of rare earth elements in high technology industries needs to be supported by developmental work for the separation of elements. The research objective is fiercely attracting and challenging considering the similarity of bath physical and chemical properties among these elements. The rate separation of samarium and yttrium elements using supported liquid membrane has been studied. Polytetrafluoroethylene (PTFE with pore size of 0.45 µm has been used as the membrane and di(2-ethylhexyl phosphate (D2EHP in hexane has been used as a carrier and nitric acid solution has been used as receiving phase. Result of experiments showed that the best separation rate of samarium and yttrium elements could be obtained at feeding phase of pH 3.0, di(2-ethylhexyl phosphate (D2EHP concentration of 0.3 M, agitation rate of 700 rpm, agitation time of 2 hours, and nitric acid and its solution concentrations of 1.0 M and 0.1 M, respectively. At this condition, separation rates of samarium and yttrium were 64.4 and 67.6%, respectively.   Keywords: liquid membrane, rare earth elements, samarium, yttrium

Samarium (III Selective Membrane Sensor Based on Tin (IV Boratophosphate

Directory of Open Access Journals (Sweden)

Ashok S. K. Kumar

2004-08-01

Full Text Available Abstract: A number of Sm (III selective membranes of varying compositions using tin (IV boratophosphate as electroactive material were prepared. Polyvinyl chloride, polystyrene and epoxy resin were used as binding materials. Membrane having composition of 40% exchanger and 60% epoxy resin exhibited best performance. This membrane worked well over a wide concentration range of 1x10-5M to 1x10-1 M of samarium ions with a Super-Nernstian slope of 40 mV/decade. It has a fast response time of less than 10 seconds and can be used for at least six months without any considerable divergence in potentials. The proposed sensor revealed good selectivities with respect to alkali, alkaline earth, some transition and rare earth metal ions and can be used in the pH range of 4.0-10.0. It was used as an indicator electrode in the potentiometric titration of Sm (III ions against EDTA. Effect of internal solution was studied and the electrode was successfully used in non-aqueous media, too.

Fabrication of a PVC membrane samarium(III) sensor based on N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide as a selectophore

Energy Technology Data Exchange (ETDEWEB)

Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Naghavi-Reyabbi, Fatemeh [Resident of General Surgery, Endoscopic and Minimaly Invasive Surgery Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Tadjarodi, Azadeh; Rad, Maryam [Department of Chemistry, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

2013-03-01

A new ion-selective electrode for Sm{sup 3+} ion is described based on the incorporation of N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide (TPTA) in a poly(vinylchloride) (PVC) matrix. The membrane sensor comprises nitrobenzene (NB) as a plasticizer, and oleic acid (OA) as an anionic additive. The sensor with the optimized composition shows a Nernstian potential response of 19.8 {+-} 0.5 mV decade{sup -1} over a wide concentration range of 1.0 Multiplication-Sign 10{sup -2} and 1 Multiplication-Sign 10{sup -6} mol L{sup -1}, with a lower detection limit of 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} and satisfactor applicable pH range of 3.6-9.2. Having a short response time of less than 10 s and a very good selectivity towards the Sm{sup 3+} over a wide variety of interfering cations (e.g. alkali, alkaline earth, transition and heavy metal ions) the sensor seemed to be a promising analytical tool for determination of the Sm{sup 3+}. Hence, it was used as an indicator electrode in the potentiometric titration of samarium ion with EDTA. It was also applied to the direct samarium recovery in binary mixtures. - Highlights: Black-Right-Pointing-Pointer A new Sm{sup 3+}-PVC membrane sensor is introduced for determination of Sm{sup 3+} ions in the solutions. Black-Right-Pointing-Pointer N,N Prime ,N Double-Prime -tris(4-pyridyl)trimesic amide was used as a suitable selectophore for samarium sensor. Black-Right-Pointing-Pointer Detection limit of the sensor is 4.7 Multiplication-Sign 10{sup -7} mol L{sup -1} with a short response time of less than 10 s.

Preparation and examination of properties of samarium-153-EDTMP complex

International Nuclear Information System (INIS)

Nowak, M.; Garnuszek, P.; Lukasiewicz, A.; Wozniak, I.; Zulczyk, W.; Licinska, I.

1995-01-01

Preparation and properties of ethylenediaminetetramethylenephosphonic acid (EDTMP) as well as some properties of 153 Sm-EDTMP chelate have been examined. The chelate formed by samarium-153 (46.3 h, β - -decay) with EDTMP exhibits high bone uptake and can be used for treatment of disseminated, painful skeletal metastases. The purity and stability of solutions of 153 Sm-EDTMP chelate were examined in a broad range of samarium concentration and 153 Sm specific activity. The complex under study was examined by radio-TLC, -electrophoresis and radio-HPLC. The results obtained suggest the small size of molecules of 153 Sm-EDTMP chelate as compared with molecules of ''free''EDTMP. The results of biodistribution of 153 Sm-EDTMP determined in rats indicate the quick blood clearance, high deposition of radioactivity in bone and quick excretion of radioactivity into urine. No specific uptake of 153 Sm-EDTMP in extra-skeletal organs was found. (author). 42 refs, 13 figs, 22 tabs

Expedient Method for Samarium(II) Iodide Preparation Utilizing a Flow Approach

Czech Academy of Sciences Publication Activity Database

Voltrová, Svatava; Šrogl, Jiří

2013-01-01

Roč. 24, č. 3 (2013), s. 394-396 ISSN 0936-5214 R&D Projects: GA MŠk LH12013 Institutional support: RVO:61388963 Keywords : flow * samarium * iodide * reduction Subject RIV: CC - Organic Chemistry Impact factor: 2.463, year: 2013

Optical properties of zinc–vanadium glasses doped with samarium ...

Indian Academy of Sciences (India)

Abstract. Zinc–vanadium glasses doped with samarium oxide having the chemical composition Sm2O3(x). ZnO(40−x)V2O5(60)(where x = 0·1–0·5 mol%) were prepared by melt quenching method. The density of these glasses was measured by Archimedes method; the corresponding molar volumes have also been ...

X-ray spectrum in the range (6-12) A emitted by laser-produced plasma of samarium

International Nuclear Information System (INIS)

Louzon, Einat; Henis, Zohar; Levi, Izhak; Hurvitz, Gilad; Ehrlich, Yosi; Fraenkel, Moshe; Maman, Shlomo; Mandelbaum, Pinchas

2009-01-01

A detailed analysis of the x-ray spectrum emitted by laser-produced plasma of samarium (6-12 A) is presented, using ab initio calculations with the HULLAC relativistic code and isoelectronic considerations. Resonance 3d-nf (n=4 to 7), 3p-4d, 3d-4p, and 3p-4s transitions in Ni samarium ions and in neighboring ionization states (from Mn to Zn ions) were identified. The experiment results show changes in the fine details of the plasma spectrum for different laser intensities.

Characteristics of mechanical alloying of Zn-Al-based alloys

International Nuclear Information System (INIS)

Zhu, Y.H.; Hong Kong Polytechnic; Perez Hernandez, A.; Lee, W.B.

2001-01-01

Three pure elemental powder mixtures of Zn-22%Al-18%Cu, Zn-5%Al-11%Cu, and Zn-27%Al-3%Cu (in wt.%) were mechanically alloyed by steel-ball milling processing. The mechanical alloying characteristics were investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques. It was explored that mechanical alloying started with the formation of phases from pure elemental powders, and this was followed by mechanical milling-induced phase transformation. During mechanical alloying, phases stable at the higher temperatures formed at the near room temperature of milling. Nano-structure Zn-Al-based alloys were produced by mechanical alloying. (orig.)

Synthesis of samarium binding bleomycin - a possible NCT radiosensitizer

Energy Technology Data Exchange (ETDEWEB)

Mendes, B.M., E-mail: bmm@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Mendes, T.M.; Campos, T.P.R., E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2011-07-01

Bleomycin (BLM) is a drug that has attractive features for the development of a new radiopharmaceutical, particularly with regard to neutron capture therapy (NCT) sensitized by Sm-149. It has the ability to chelate many metal ions. In vitro studies have shown that up to 78% of BLM present in a cell is accumulated inside the nucleus or in the nuclear membrane. In addition, this drug has higher affinity for tumor tissues than for normal tissues. Radioactive isotopes carried by this antibiotic would be taken preferentially to one important cellular targets DNA. Besides, BLM displays intrinsic anti-tumor activity - it is a chemotherapic antibiotic clinically used against some cancers. This study aimed to obtain bleomycin molecules bound to samarium (BLM-Sm) for NCT studies in vitro and in vivo. The binding technique employed in this work has great simplicity and low cost. Thin layer chromatography, high performance liquid chromatography, fast protein liquid chromatography and analysis by ICP-AES were applied to verify the binding molecule. ICP-AES results showed the presence of samarium in the sample peaks related to BLM-Sm. However, efficiency and stability of this bond needs to be investigated. (author)

Synthesis of samarium binding bleomycin - a possible NCT radiosensitizer

International Nuclear Information System (INIS)

Mendes, B.M.; Mendes, T.M.; Campos, T.P.R.

2011-01-01

Bleomycin (BLM) is a drug that has attractive features for the development of a new radiopharmaceutical, particularly with regard to neutron capture therapy (NCT) sensitized by Sm-149. It has the ability to chelate many metal ions. In vitro studies have shown that up to 78% of BLM present in a cell is accumulated inside the nucleus or in the nuclear membrane. In addition, this drug has higher affinity for tumor tissues than for normal tissues. Radioactive isotopes carried by this antibiotic would be taken preferentially to one important cellular targets DNA. Besides, BLM displays intrinsic anti-tumor activity - it is a chemotherapic antibiotic clinically used against some cancers. This study aimed to obtain bleomycin molecules bound to samarium (BLM-Sm) for NCT studies in vitro and in vivo. The binding technique employed in this work has great simplicity and low cost. Thin layer chromatography, high performance liquid chromatography, fast protein liquid chromatography and analysis by ICP-AES were applied to verify the binding molecule. ICP-AES results showed the presence of samarium in the sample peaks related to BLM-Sm. However, efficiency and stability of this bond needs to be investigated. (author)

New reduced variant in gadolinium and samarium monoxide thin films

Energy Technology Data Exchange (ETDEWEB)

Bist, B M.S.; Kumar, J; Srivastava, O N [Banaras Hindu Univ. (India). Dept. of Physics

1977-01-01

A new reduced phase has been observed in the thin films of gadolinium and samarium monoxides. This phase results on imparting an annealing treatment to the monoxides and is formed as a result of the creation and ordering of vacancies in the oxygen sublattice. The new phase has been analysed to possess a rhombohedral unit cell with lattice parameters a/sub R/ = a/sub 0/ square root of (3/2) and c/sub R/ = a/sub 0/ square root of 3 (based on hexagonal axes, a/sub 0/ being the lattice parameter of the fundamental zinc blende type unit cell of the monoxide). Based on the proposed structure, the new phase can be assigned the solid state chemical formula RO/sub x/ where R = Gd, Sm and x = 0.66.

Influence of pretreatment temperature cycling on the radiating defect formation in silicon doped by samarium

International Nuclear Information System (INIS)

Abdurakhmanov, K.P.; Nazyrov, D.E.

2006-01-01

Full text: The raise of thermal and radiation stability as it is known, is one of actual problems of physics semiconductors. Recently it is established, that the rare-earth elements (REE) raise a stability of silicon to exterior action. In this connection the investigation of silicon doped REE by samarium and influence on its properties of heat treatments and radiation exposure is important. In sectional operation the outcomes of investigations of influence of samarium on thermal (600 degree C are reduced; 600 deg. + 900 deg. C; 900 deg. C; 900 deg. C + 600 deg. C; 1100 deg. C; 600 deg. C + 900 deg. C + 1100 deg. C; 900 deg. C + 600 deg. C + 1100 deg. C) thermal defect formation and radiation defect formation (exposure of γ-quanta 60 Co) both in beforehand wrought, and in thermally unfinished samples. After each cycle of heat treatments samples cool fast (throwing off in oil) or slowly (together with the furnace). Doping n-silicon REE by gadolinium and samarium was carried out during cultivation. The concentration of gadolinium and samarium in silicon, on sectional of a neutron-activation analysis was equaled 10 14 - 10 18 cm -3 . As control is model monocrystal silicon such as KEP-15/50. Para-meters of deep levels originating in control and doped REE samples, both past heat treatment or temperature cycling, and irradiated by the γ-quanta are defined by methods of a capacity spectroscopy: DLTS and IRC. The obtained outcomes have shown, that in irradiated with the γ-quanta 60 Co deep levels samples are formed with energies: E C -0,17 eV, E C -0,32 eV, EC-0,41 eV. Thus the parameters of deep levels vary depending on requirements of prestress heat treatment. For example heat treatment at 600 deg. C essentially increments a velocity of introduction of and centre (deep level of E C -0,17 eV), in comparison with a velocity of introduction of this level in samples with prestress heat treatment at 900 deg. C. In samples n-Si doped by samarium effectiveness of formation

Sorption of samarium in iron (II) and (III) phosphates in aqueous systems

International Nuclear Information System (INIS)

Diaz F, J.C.

2006-01-01

The radioactive residues that are stored in the radioactive confinements its need to stay isolated of the environment while the radioactivity levels be noxious. An important mechanism by which the radioactive residues can to reach the environment, it is the migration of these through the underground water. That it makes necessary the investigation of reactive materials that interacting with those radionuclides and that its are able to remove them from the watery resources. The synthesis and characterization of materials that can be useful in Environmental Chemistry are very important because its characteristics are exposed and its behavior in chemical phenomena as the sorption watery medium is necessary to use it in the environmental protection. In this work it was carried out the sorption study of the samarium III ion in the iron (II) and (III) phosphate; obtaining the sorption isotherms in function of pH, of the phosphate mass and of the concentration of the samarium ion using UV-visible spectroscopy to determine the removal percentage. The developed experiments show that as much the ferrous phosphate as the ferric phosphate present a great affinity by the samarium III, for what it use like reactive material in contention walls can be very viable because it sorption capacity has overcome 90% to pH values similar to those of the underground and also mentioning that the form to obtain these materials is very economic and simple. (Author)

Application of mechanical alloying to synthesis of intermetallic phases based alloys

International Nuclear Information System (INIS)

Dymek, S.

2001-01-01

Mechanical alloying is the process of synthesis of powder materials during milling in high energetic mills, usually ball mills. The central event in mechanical alloying is the ball-powder-ball collision. Powder particles are trapped between the colliding balls during milling and undergo deformation and/or fracture. Fractured parts are cold welded. The continued fracture and cold welding results in a uniform size and chemical composition of powder particles. The main applications of mechanical alloying are: processing of ODS alloys, syntheses of intermetallic phases, synthesis of nonequilibrium structures (amorphous alloys, extended solid solutions, nanocrystalline, quasi crystals) and magnetic materials. The present paper deals with application of mechanical alloying to synthesis Ni A l base intermetallic phases as well as phases from the Nb-Al binary system. The alloy were processed from elemental powders. The course of milling was monitored by scanning electron microscopy and X-ray diffraction. After milling, the collected powders were sieved by 45 μm grid and hot pressed (Nb alloys and NiAl) or hot extruded (NiAl). The resulting material was fully dense and exhibited fine grain (< 1 μm) and uniform distribution of oxide dispersoid. The consolidated material was compression and creep tested. The mechanical properties of mechanically alloys were superior to properties of their cast counterparts both in the room and elevated temperatures. Higher strength of mechanically alloyed materials results from their fine grains and from the presence of dispersoid. At elevated temperatures, the Nb-Al alloys have higher compression strength than NiAl-based alloys processed at the same conditions. The minimum creep rates of mechanically alloyed Nb alloys are an order of magnitude lower than analogously processed NiAl-base alloys. (author)

JAEA thermodynamic database for performance assessment of geological disposal of high-level and TRU wastes. Refinement of thermodynamic data for trivalent actinoids and samarium

International Nuclear Information System (INIS)

Kitamura, Akira; Fujiwara, Kenso; Yui, Mikazu

2010-01-01

Within the scope of the JAEA thermodynamic database project for performance assessment of geological disposal of high-level radioactive and TRU wastes, the refinement of the thermodynamic data for the inorganic compounds and complexes of trivalent actinoids (actinium(III), plutonium(III), americium(III) and curium(III)) and samarium(III) was carried out. Refinement of thermodynamic data for these elements was based on the thermodynamic database for americium published by the Nuclear Energy Agency in the Organisation for Economic Co-operation and Development (OECD/NEA). Based on the similarity of chemical properties among trivalent actinoids and samarium, complementary thermodynamic data for their species expected under the geological disposal conditions were selected to complete the thermodynamic data set for the performance assessment of geological disposal of radioactive wastes. (author)

Impact of educational strategies in positioning Samarium-153 EDTMP as a treatment for metastatic bone pain

International Nuclear Information System (INIS)

Seminario, C.; Morales, R.; Castro, M.; Cano, R.A.; Mendoza, G.

2005-01-01

To educate is a difficult task but its results make efforts worthwhile. Many patients in Peru suffer from intractable bone pain due to metastases. Since 1993 radionuclides were used to palliate bone pain due to metastases in Peru. First, with the help of the IAEA, Peru participated in a clinical trial using Phosphorus 32 and Strontium 89. Then, efforts were performed to produce Samarium 153 EDMTP locally, which was achieved in 1995. Nevertheless, years passed and Samarium use did not increase proportionally to the needs of people with cancer and bone pain, mainly the poor. Educational strategies have been proven useful for delivering solutions to many health problems in other diseases and also in cancer. Health education makes patients and their relatives assume responsible care of their problems. The purpose of this work was to increase Samarium EDTMP use as palliative treatment in patients with bone pain due to metastases, using educational strategies as means to change attitudes towards this health problem. In September 2003, a task group conducted studies in order to apply several methods to achieve the goal of increasing Samarium EDTMP use. Educational strategies employed were performed to provide verbal and written information to patients, physicians, medical students, residents, pain specialists, oncologists and neurologists, as well as general public. Verbal information included radio interviews, television spots and a phone number (in charge of two secretaries, prepared for answering and if not possible, a physician was in charge of attending patient consultation), e-mail and a web page for consultation. Written material was delivered to several newspapers, including clinical use of Samarium, possibilities of being elected for treatment, benefits and risks and a photography of the product. Politics of the institution producing Samarium changed, in order to achieve minimum cost of the product and it was delivered to all publics at the lowest cost for a year

Lanthanum (samarium) nitrate-4-aminoantipyrine nitrate-water systems

International Nuclear Information System (INIS)

Starikova, L.I.; Zhuravlev, E.F.

1985-01-01

Using the isothermal method of cross-sections at 50 deg C systems lanthanum nitrate-4-aminoantipyrine nitrate-water (1), samarium nitrate-4-aminoantipyrine nitrate-water (2), are studied. Isotherms of system 1 consist of two crystallization branches of initial salt components. In system 2 formation of congruently soluble compounds of the composition Sm(No) 3 ) 3 xC 11 H 13 ON 3 xHNO 3 is established. Analytical, X-ray phase and thermogravimetric analysis of the isolated binary salt are carried out

Collective effects in even-mass samarium isotopes by polarized-proton scattering

NARCIS (Netherlands)

Petit, R.M.A.L.; Hall, van P.J.; Klein, S.S.; Moonen, W.H.L.; Nijgh, G.J.; Overveld, van C.W.A.M.; Poppema, O.J.

1993-01-01

The even-mass samarium isotopes 148,...,152Sm have been investigated by polarized proton scattering at 20.4 MeV beam energy. The data have been analysed with an 'extended' optical model, where the intensities of the first maxima of the main inelastic channels are fitted in a coupled-channels

Synthesis of samarium, europium and ytterbium acetylenides

International Nuclear Information System (INIS)

Bochkarev, M.N.; Fedorova, E.A.; Glushkova, N.V.; Protchenko, A.V.; Druzhkov , O.N.; Khorshev, S.Ya.

1995-01-01

Ethynyl complexes of samarium, europium and ytterbium were prepared by interaction of naphthalinides of metals with acetylene in tetrahydrofuran. The compounds are isolated in the form of dark-coloured pyrophore powders. Data of magnetic measurements suggest that in the course of the reaction Sm(2) is oxidized completely to Sm(3), Yb(2) transforms into Yb(3) partially, whereas europium preserves its initial bivalent state. Hydrolysis of the compounds prepared provides acetylene, ethylene, ethane and hydrogen which indicates the presence of acethylenide Ln 2 C 2 and hydride LnH groupings (Ln = Sm, Eu, Yb). 9 refs., 2 tabs

Vanadium-base alloys for fusion reactor applications

International Nuclear Information System (INIS)

Smith, D.L.; Loomis, B.A.; Diercks, D.R.

1984-10-01

Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R and D) needs are defined

Vanadium-base alloys for fusion reactor applications

Energy Technology Data Exchange (ETDEWEB)

Smith, D.L.; Loomis, B.A.; Diercks, D.R.

1984-10-01

Vanadium-base alloys offer potentially significant advantages over other candidate alloys as a structural material for fusion reactor first wall/blanket applications. Although the data base is more limited than that for the other leading candidate structural materials, viz., austenitic and ferritic steels, vanadium-base alloys exhibit several properties that make them particularly attractive for the fusion reactor environment. This paper presents a review of the structural material requirements, a summary of the materials data base for selected vanadium-base alloys, and a comparison of projected performance characteristics compared to other candidate alloys. Also, critical research and development (R and D) needs are defined.

Sorption-desorption of samarium in Febex bentonite

International Nuclear Information System (INIS)

Ramirez-Guinart, O.; Rigol, A.; Vidal, M.; Fernandez-Poyatos, P.; Alba, M. D.

2012-01-01

Document available in extended abstract form only. The chemical and physical nature of the clay is a key issue in the design of engineered barriers. The FEBEX bentonite is one of the clays candidates to be used in engineered barriers in deep geology repositories (DGR). Here, its performance was tested with respect to the sorption-desorption of samarium, which is a lanthanide that, besides being considered as a natural analogue of actinides, may also be present in high level radioactive waste in the form of the radioactive isotope 151 Sm. FEBEX bentonite was used in this study. This is a di-octahedral smectite, with isomorphic substitutions in tetrahedral and octahedral sheets. Its theoretical cation exchange capacity value is 1500 meq kg -1 . Sorption isotherms were obtained for Sm in the range of initial concentrations of 0.01 and 9 meq l -1 . Tests were carried out in deionized water and in a medium simulating the composition of interstitial water. Sorption tests were performed equilibrating 30 ml of the Sm solution with 0.2 g of clay. After a contact time of 24 hours, supernatants were decanted off after centrifugation. The quantification of the concentration of Sm in the initial and final solutions allowed us to quantify the Sm equilibrium concentration (C eq ), the fraction sorbed in the FEBEX bentonite (C sorb ) and to derive the sorption K d data. Desorption tests were applied to determine the desorption K d and the percentage of Sm reversibly sorbed. Desorption tests were performed with the bentonite residue from the sorption step, under the same experimental conditions, but without Sm. Powder X-ray diffractograms were obtained from 3 to 70 deg. 2θ with a step of 0.05 deg. and a counting time of 3 s. The crystalline phases were identified using the computer program X'Pert HighScore. The morphology of the samples was analyzed by SEM at 20 kV. An EDX system was fitted to the SEM equipment to perform chemical analyses of the samples using a Si/Li detector

Processing and properties of Nb-Ti-based alloys

International Nuclear Information System (INIS)

Sikka, V.K.; Viswanathan, S.

1992-01-01

The processing characteristics, tensile properties, and oxidation response of two Nb-Ti-Al-Cr alloys were investigated. One creep test at 650 C and 172 MPa was conducted on the base alloy which contained 40Nb-40Ti-10Al-10Cr. A second alloy was modified with 0.11 at. % carbon and 0.07 at. % yttrium. Alloys were arc melted in a chamber backfilled with argon, drop cast into a water-cooled copper mold, and cold rolled to obtain a 0.8-mm sheet. The sheet was annealed at 1,100 C for 0.5 h. Longitudinal tensile specimens and oxidation specimens were obtained for both the base alloy and the modified alloy. Tensile properties were obtained for the base alloy at room temperature, 400, 600, 700, 800, 900, and 1,000 C, and for the modified alloy at room temperature, 400, 600, 700, and 800 C. Oxidation tests on the base alloy and modified alloy, as measured by weight change, were carried out at 600, 700, 800, and 900 C. Both the base alloy and the modified alloy were extremely ductile and were cold rolled to the final sheet thickness of 0.8 mm without an intermediate anneal. The modified alloy exhibited some edge cracking during cold during cold rolling. Both alloys recrystallized at the end of a 0.5-h annealing treatment. The alloys exhibited moderate strength and oxidation resistance below 600 C, similar to the results of alloys reported in the literature

Laser spectroscopy of atomic samarium

International Nuclear Information System (INIS)

Barkov, L.M.; Melik-Pashaev, D.A.; Zolotorev, M.S.

1988-01-01

Samarium spectrum was studied with a purpose to find transitions to be used in experiments on parity nonconservation. Macaluso-Corbino effect - Faraday rotation near resonance was used for the search and study of spectral lines. We have identified previously unknown energy levels belonging to the 4f 5 6s 2 5 D term: 15914.55(3) cm -4 (J=1), 17864.29(3) cm -4 (J=2), 20195.76(3) cm -4 (J=3). M1-transitions to these levels from the levels of the ground 4f 5 6s 2 7 F term were observed. There are several peculiarities of these transitions which are due to the fact that they occut within an inner 4f 5 -shell, particularly, a very small presuure broadening by inert gases. 44 refs.; 17 figs.; 7 tabs

A sulfidation-resistant nickel-base alloy

International Nuclear Information System (INIS)

Lai, G.Y.

1989-01-01

For applications in mildly to moderately sulfidizing environments, stainless steels, Fe-Ni-Cr alloys (e.g., alloys 800 and 330), and more recently Fe-Ni-Cr-Co alloys (e.g., alloy 556) are frequently used for construction of process equipment. However, for many highly sulfidizing environments, few existing commercial alloys have adequate performance. Thus, a new nickel-based alloy containing 27 wt.% Co, 28 wt.% Cr, 4 wt.% Fe, 2.75 wt.% Si, 0.5 wt.% Mn and 0.05 wt.% C (Haynes alloy HR-160) was developed

Nickel base alloys

International Nuclear Information System (INIS)

Gibson, R.C.; Korenko, M.K.

1980-01-01

Nickel based alloy, the characteristic of which is that it mainly includes in percentages by weight: 57-63 Ni, 7-18 Cr, 10-20 Fe, 4-6 Mo, 1-2 Nb, 0.2-0.8 Si, 0.01-0.05 Zr, 1.0-2.5 Ti, 1.0-2.5 Al, 0.02-0.06 C and 0.002-0.015 B. The aim is to create new nickel-chromium alloys, hardened in a solid solution and by precipitation, that are stable, exhibit reduced swelling and resistant to plastic deformation inside the reactor. These alloys of the gamma prime type have improved mechanical strengthm swelling resistance, structural stability and welding properties compared with Inconel 625 [fr

Removal of trivalent samarium from aqueous solutions by activated biochar derived from cactus fibres

Institute of Scientific and Technical Information of China (English)

Loukia Hadjittofi; Styliana Charalambous; Ioannis Pashalidis

2016-01-01

The efficiency of activated biochar fibres obtained fromOpuntia Ficus Indica regarding the sorption of trivalent samarium (Sm(III)) from aqueous solutions was investigated by batch experiments. The effect of various physicochemical parameters (e.g. pH, initial metal concentration, ionic strength, temperature and contact time) on the Sm(III) adsorption was studied and the surface species were characterized by FTIR spectroscopy prior to and after the lanthanide sorption. The experimental results showed that the acti-vated biochar fibres possessed extraordinary sorption capacity for Sm(III) in acidic solutions (qmax=90 g/kg, pH 3.0) and near neutral solutions (qmax=350 g/kg, pH 6.5). This was attributed to the formation of samarium complexes with the surface carboxylic moieties, available in high density on the lamellar structures of the bio-sorbent.

Nickel and cobalt base alloys

International Nuclear Information System (INIS)

Houlle, P.

1994-01-01

Nickel base alloys have a good resistance to pitting, cavernous or cracks corrosion. Nevertheless, all the nickel base alloys are not equivalent. Some differences exit between all the families (Ni, Ni-Cu, Ni-Cr-Fe, Ni-Cr-Fe-Mo/W-Cu, Ni-Cr-Mo/W, Ni-Mo). Cobalt base alloys in corrosive conditions are generally used for its wear and cracks resistance, with a compromise to its localised corrosion resistance properties. The choice must be done from the perfect knowledge of the corrosive medium and of the alloys characteristics (chemical, metallurgical). A synthesis of the corrosion resistance in three medium (6% FeCl 3 , 4% NaCl + 1% HCl + 0.1% Fe 2 (SO 4 ) 3 , 11.5% H 2 SO 4 + 1.2% HCl + 1% Fe 2 (SO 4 ) 3 + 1% CuCl 2 ) is presented. (A.B.). 11 refs., 1 fig., 12 tabs

Engineering data bases for refractory alloys

International Nuclear Information System (INIS)

Cooper, R.H. Jr.; Harms, W.O.

1985-01-01

Refractory alloys based on niobium, molybdenum, tantalum, and tungsten are required for the multi-100kW(e) space nuclear reactor power concepts that have been assessed in the SP-100 Program because of the extremely high temperatures involved. A review is presented of the technology efforts on the candidate refractory alloys in the areas of availability/fabricability, mechanical properties, irradiation effects, and compatibility. Of the niobium-base alloys, only Nb-1Zr has a data base that is sufficiently comprehensive for the high level of confidence required in the reference-alloy selection process for the reactor concept to be tested in the Ground Engineering System (GES) Phase of the SP-100 Program. Based on relatively short-term tests, the alloy PWC-11 (Nb-1Zr-0.1C) appears to have significantly greater creep strength than Nb-1Zr; however, concerns as to whether this precipitation-hardened alloy will remain thermally stable during seven years of full-power reactor operation need to be resolved. Additional information on the reference GES alloy will be needed for the detailed engineering design of a space power system and the fabrication of prototypical GES test components. Expedient development and demonstration of an adequate total manufacturing capability will be required if a high risk of significant schedule slippages and cost overruns is to be avoided. 4 refs., 1 fig., 3 tabs

New Developments of Ti-Based Alloys for Biomedical Applications

Science.gov (United States)

Li, Yuhua; Yang, Chao; Zhao, Haidong; Qu, Shengguan; Li, Xiaoqiang; Li, Yuanyuan

2014-01-01

Ti-based alloys are finding ever-increasing applications in biomaterials due to their excellent mechanical, physical and biological performance. Nowdays, low modulus β-type Ti-based alloys are still being developed. Meanwhile, porous Ti-based alloys are being developed as an alternative orthopedic implant material, as they can provide good biological fixation through bone tissue ingrowth into the porous network. This paper focuses on recent developments of biomedical Ti-based alloys. It can be divided into four main sections. The first section focuses on the fundamental requirements titanium biomaterial should fulfill and its market and application prospects. This section is followed by discussing basic phases, alloying elements and mechanical properties of low modulus β-type Ti-based alloys. Thermal treatment, grain size, texture and properties in Ti-based alloys and their limitations are dicussed in the third section. Finally, the fourth section reviews the influence of microstructural configurations on mechanical properties of porous Ti-based alloys and all known methods for fabricating porous Ti-based alloys. This section also reviews prospects and challenges of porous Ti-based alloys, emphasizing their current status, future opportunities and obstacles for expanded applications. Overall, efforts have been made to reveal the latest scenario of bulk and porous Ti-based materials for biomedical applications. PMID:28788539

Pressure and irradiation effects on transport properties of samarium compounds with instable valence

International Nuclear Information System (INIS)

Morillo, J.

1981-01-01

Electron transport properties in samarium compounds with instable valence are studied in this thesis: from SmS in its integer valence phases at common pressure to SmB 6 compound IV at common pressure through SmSsub(1-x)Psub(x) (x 6 is presented [fr

Graphite furnace atomic absorption spectrometry with a tantalum boat for the determination of yttrium, samarium, and dysprosium in a mish metal

International Nuclear Information System (INIS)

Daidoji, Hidehiro; Tamura, Shohei

1982-01-01

The determination of yttrium, samarium, and dysprodium by means of graphite-furnace atomic absorption spectrometry (AAS) was studied by a tantalum boat inserted into a graphite tube atomizer. These elements could not be determined by the use of a commercial graphite tube, In the atomization from a tantalum boat, better analytical sensitivities and negligible memory effects for these rare earths are obtained. The analytical sensitivities of yttrium, samarium, and dysprodium with the tantalum boat were 0.60 ng, 0.86 ng, and 0.17 ng respectively. This method was applied for the determination of yttrium, samarium, and dysprosium in a mish metal. The measurements were performed with slightly acidified solutions (0.01 mol dm 3 HCI or HNO 3 ). The sensitivities and the precisions for these elements decreased with increasing acid concentration. An enhancement in the sensitivities of yttrium and dysprosium upon the addition of a large excess of lanthanum, neodymium, and praseodymium salts were observed. The yttrium, samarium, and dysprosium in a mish metal were determined with both analytical curves of standard solutions containing an excess of lanthanum, cerium, and neodymium ions and of the standard addition. The precisions for this work were in the 3 - 9.3% range. (author)

Ekstraksi Pemisahan Neodimium dari Samarium, Itrium dan Praseodimium Memakai Tri Butil Fosfat

Directory of Open Access Journals (Sweden)

Maria Veronica Purwani

2017-05-01

Full Text Available The extraction of Nd(OH3 (neodymium hydroxide concentrate containing Y (yttrium, Sm (samarium and Pr (praseodymium as product of monazite processed has been done. The purpose of this study is to determine the separation of Nd from Y, Pr and Nd Sm in Nd concentrate. The aqueous phase was concentrated Nd (OH3 in HNO3 and extractant while organic phase was Tri Butyl Phosphate (TBP in kerosene. Parameters studied were pH and concentration feed, concentration of TBP in kerosene, extraction time and stirring speed. The result showed that the optimization of separation extraction neodymium from samarium, yttrium and praseodymium in Nd(OH3 concentrated with TBP, obtained the optimum condition of pH = 0.2, concentration of feed 100 g /L, concentration of TBP in kerosene 5%, extraction time 15 minutes and stirring speed 150 rpm. With the conditions, Separation Factor (SF obtained for Nd-Y, Nd-Pr, Nd-Sm are 2.242, 4.811, 4.002 respectively, while D and extraction efficiency of Nd are 0.236 and 19.07%.

Variations of color with alloying elements in Pd-free Au-Pt-based high noble dental alloys

International Nuclear Information System (INIS)

Shiraishi, Takanobu; Takuma, Yasuko; Miura, Eri; Fujita, Takeshi; Hisatsune, Kunihiro

2007-01-01

The effects of alloying addition of a small amount of base metals (In, Sn, Fe, Zn) on color variations in Pd-free Au-Pt-based high noble dental alloys were investigated in terms of rectilinear and polar color coordinates. The ternary Au-Pt-X (X = In, Sn, Fe, Zn) and quaternary Au-Pt-In-Y (Y = Sn, Fe, Zn) alloys were prepared from high purity component metals. The amount of alloying base metals, X and Y, were restricted up to 2 at.%. The alloying addition of a small amount of Fe, In, Sn, to a binary Au-10 at.% Pt alloy (referred to as AP10) effectively increased chroma, C *. On the other hand, the addition of Zn to the parent alloy AP10 did not change color coordinates greatly. The increase in chroma in the present Au-Pt-based high noble alloys was attributed to the increase in the slope of spectral reflectance curve at its absorption edge near 515 nm. It was found that the addition of a small amount of Fe to the parent alloy AP10 markedly increased lightness, L *, and the addition of Sn gave a very light tint of red to the parent alloy. Although red-green chromaticity index a * contributed to chroma to some extent, contribution of yellow-blue chromaticity index b * was much greater in determining chroma in this Pd-free Au-Pt-based multi-component alloys. The present results are expected to be valuable in case color is to be taken into account in designing Pd-free Au-Pt-based high noble dental alloys

Variations of color with alloying elements in Pd-free Au-Pt-based high noble dental alloys

Energy Technology Data Exchange (ETDEWEB)

Shiraishi, Takanobu [Department of Dental and Biomedical Materials Science, Unit of Basic Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588 (Japan)]. E-mail: siraisi@nagasaki-u.ac.jp; Takuma, Yasuko [Department of Dental and Biomedical Materials Science, Unit of Basic Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588 (Japan); Miura, Eri [Department of Dental and Biomedical Materials Science, Unit of Basic Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588 (Japan); Fujita, Takeshi [Department of Dental and Biomedical Materials Science, Unit of Basic Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588 (Japan); Hisatsune, Kunihiro [Department of Dental and Biomedical Materials Science, Unit of Basic Medical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588 (Japan)

2007-06-15

The effects of alloying addition of a small amount of base metals (In, Sn, Fe, Zn) on color variations in Pd-free Au-Pt-based high noble dental alloys were investigated in terms of rectilinear and polar color coordinates. The ternary Au-Pt-X (X = In, Sn, Fe, Zn) and quaternary Au-Pt-In-Y (Y = Sn, Fe, Zn) alloys were prepared from high purity component metals. The amount of alloying base metals, X and Y, were restricted up to 2 at.%. The alloying addition of a small amount of Fe, In, Sn, to a binary Au-10 at.% Pt alloy (referred to as AP10) effectively increased chroma, C *. On the other hand, the addition of Zn to the parent alloy AP10 did not change color coordinates greatly. The increase in chroma in the present Au-Pt-based high noble alloys was attributed to the increase in the slope of spectral reflectance curve at its absorption edge near 515 nm. It was found that the addition of a small amount of Fe to the parent alloy AP10 markedly increased lightness, L *, and the addition of Sn gave a very light tint of red to the parent alloy. Although red-green chromaticity index a * contributed to chroma to some extent, contribution of yellow-blue chromaticity index b * was much greater in determining chroma in this Pd-free Au-Pt-based multi-component alloys. The present results are expected to be valuable in case color is to be taken into account in designing Pd-free Au-Pt-based high noble dental alloys.

Australian manufacture of QuadrametTM (Samarium-153 EDTMP)

International Nuclear Information System (INIS)

Wood, N.R.; Whitwell, J.

1997-01-01

Quadramet T (Samarium-153 EDTMP) has been shown overseas to be potentially useful in the palliation of painful osteoblastic skeletal metastases and has been approved this year for general marketing in the USA. Australian Radioisotopes (ARI) has licensed this product from the Australian patent holders, Dow Chemical. Within the facilities of ARI, a hot cell has been dedicated to this product and fitted out to manufacture it weekly on a cycle related to the operating cycle of the Australian reactor HIFAR. Due to neutron flux limitations of HIFAR, the local formulation has an elemental Samarium content up to 200μg/mL whereas the overseas formulation has a level of 20-46μg/mL. All other specifications of the two products are essentially the same. In 1995 and 1996 a small clinical trial with 19 patients was held which demonstrated that the pharmacokinetic behaviour was also essentially the same by measuring blood clearance rates and skeletal uptake dynamics. Soft tissue uptake was also qualitatively determined. The ARI version is now the subject of an application for general marketing within Australia. Some useful characteristics of this agent are: almost complete excretion or fixation in the skeleton within 6 hours, rapid onset of clinical effect, applicability in most cases where an abnormal diagnostic bone scan correlates with painful sites, dosage can be tailored to individual patient uptake due to easy dose measurement and retreatment is quite possible. The use of this class of agents in pain palliation continues to increase. Australian manufacture of Quadramet TM provides a further option in the management of these difficult cases

Samarium oxide as a radiotracer to evaluate the in vivo biodistribution of PLGA nanoparticles

CSIR Research Space (South Africa)

Mandiwana, V

2015-09-01

Full Text Available the biodistribution of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles containing samarium-153 oxide ([(sup153)Sm]Sm(sub2)O(sub3)) in vivo to prove that orally administered nanoparticles alter the biodistribution of a drug. These were then activated in a nuclear...

Studies on neutron irradiation effects of iron alloys and nickel-base heat resistant alloys

International Nuclear Information System (INIS)

Watanabe, Katsutoshi

1987-09-01

The present paper describes the results of neutron irradiation effects on iron alloys and nickel-base heat resistant alloys. As for the iron alloys, irradiation hardening and embrittlement were investigated using internal friction measurement, electron microscopy and tensile testings. The role of alloying elements was also investigated to understand the irradiation behavior of iron alloys. The essential factors affecting irradiation hardening and embrittlement were thus clarified. On the other hand, postirradiation tensile and creep properties were measured of Hastelloy X alloy. Irradiation behavior at elevated temperatures is discussed. (author)

Synthesis of Samarium Cobalt Nanoblades

Energy Technology Data Exchange (ETDEWEB)

Darren M. Steele

2010-08-25

As new portable particle acceleration technologies become feasible the need for small high performance permanent magnets becomes critical. With particle accelerating cavities of a few microns, the photonic crystal fiber (PCF) candidate demands magnets of comparable size. To address this need, samarium cobalt (SmCo) nanoblades were attempted to be synthesized using the polyol process. Since it is preferable to have blades of 1-2 {micro}m in length, key parameters affecting size and morphology including method of stirring, reaction temperature, reaction time and addition of hydroxide were examined. Nanoparticles consisting of 70-200 nm spherical clusters with a 3-5 nm polyvinylpyrrolidone (PVP) coating were synthesized at 285 C and found to be ferromagnetic. Nanoblades of 25nm in length were observed at the surface of the nanoclusters and appeared to suggest agglomeration was occurring even with PVP employed. Morphology and size were characterized using a transmission electron microscope (TEM). Powder X-Ray Diffraction (XRD) analysis was conducted to determine composition but no supportive evidence for any particular SmCo phase has yet been observed.

Neutron Capture and Transmission Measurements and Resonance Parameter Analysis of Samarium

International Nuclear Information System (INIS)

Leinweber, G.; Burke, J.A.; Knox, H.D.; Drindak, N.J.; Mesh, D.W.; Haines, W.T.; Ballad, R.V.; Block, R.C.; Slovacek, R.E.; Werner, C.J.; Trbovich, M.J.; Barry, D.P.; Sato, T.

2001-01-01

The purpose of the present work is to accurately measure the neutron cross sections of samarium. The most significant isotope is 149 Sm, which has a large neutron absorption cross section at thermal energies and is a 235 U fission product with a 1% yield. Its cross sections are thus of concern to reactor neutronics. Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic institute (RPI) LINAC facility using metallic and liquid Sm samples. The capture measurements were made at the 25 meter flight station with a multiplicity-type capture detector, and the transmission total cross-section measurements were performed at 15- and 25-meter flight stations with 6 Li glass scintillation detectors. Resonance parameters were determined by a combined analysis of six experiments (three capture and three transmission) using the multi-level R-matrix Bayesian code SAMMY version M2. The significant features of this work are as follows. Dilute samples of samarium nitrate in deuterated water (D 2 O) were prepared to measure the strong resonances at 0.1 and 8 eV without saturation. Disk-shaped spectroscopic quartz cells were obtained with parallel inner surfaces to provide a uniform thickness of solution. The diluent feature of the SAMMY program was used to analyze these data. The SAMMY program also includes multiple scattering corrections to capture yield data and resolution functions specific to the RPI facility. Resonance parameters for all stable isotopes of samarium were deduced for all resonances up to 30 eV. Thermal capture cross-section and capture resonance integral calculations were made using the resultant resonance parameters and were compared to results obtained using resonance parameters from ENDF/B-VI updated through release 3. Extending the definition of the capture resonance integral to include the strong 0.1 eV resonance in 149 Sm, present measurements agree within estimated uncertainties with En

Applications of thermodynamic calculations to Mg alloy design: Mg-Sn based alloy development

International Nuclear Information System (INIS)

Jung, In-Ho; Park, Woo-Jin; Ahn, Sang Ho; Kang, Dae Hoon; Kim, Nack J.

2007-01-01

Recently an Mg-Sn based alloy system has been investigated actively in order to develop new magnesium alloys which have a stable structure and good mechanical properties at high temperatures. Thermodynamic modeling of the Mg-Al-Mn-Sb-Si-Sn-Zn system was performed based on available thermodynamic, phase equilibria and phase diagram data. Using the optimized database, the phase relationships of the Mg-Sn-Al-Zn alloys with additions of Si and Sb were calculated and compared with their experimental microstructures. It is shown that the calculated results are in good agreement with experimental microstructures, which proves the applicability of thermodynamic calculations for new Mg alloy design. All calculations were performed using FactSage thermochemical software. (orig.)

Electron beam and laser surface alloying of Al-Si base alloys

International Nuclear Information System (INIS)

Vanhille, P.; Tosto, S.; Pelletier, J.M.; Issa, A.; Vannes, A.B.; Criqui, B.

1992-01-01

Surface alloying on aluminium-base alloys is achieved either by using an electron beam or a laser beam, in order to improve the mechanical properties of the near-surface region. A predeposit of nickel is first realized by plasma spraying. Melting of both the coating and part of the substrate produces a surface alloy with a fine, dendritic microstructure with a high hardness. Enhancement of this property requires an increase in the nickel content. Various problems occur during the formation of nickel-rich surface layers: incomplete homogenization owing to a progressive increase of the liquidus temperature, cracks owing to the brittleness of this hard suface alloy, formation of a plasma when experiments are carried out in a gaseous environment (laser surface alloying). Nevertheless, various kinds of surface layers may be achieved; for example very hard surface alloys (HV 0.2 =900), with a thickness of about 500-600 μm, or very thick surface alloys (e>2 mm), with a fairly good hardness (greater than 350 HV 0.2 ). Thus, it is possible to obtain a large variety of new materials by using high energy beams on aluminium substrates. (orig.)

Progress in development of iron base alloys

International Nuclear Information System (INIS)

Zackay, V.V.; Parker, E.R.

1980-01-01

The ways of development of new iron base high-strength alloys are considered. Perspectiveness of ferritic steel strengthening with intermetallides (TaFe 2 , for instance) is shown. Favourable combination of plasticity, strength and fracture toughness in nickel-free iron-manganese alloys (16-20%) is also pointed out. A strength level of alloyed maraging steels can be achieved by changes in chemical composition and by proper heat treatments of low- and medium-alloyed steels

Identification of the lines in the L emission spectrum of cerium and samarium

International Nuclear Information System (INIS)

Shrivastava, B.D.; Singh, D.

1992-01-01

The occurrence of a line at 2.1556 A in the L emission spectrum of cerium and two lines at 1.6679 and 1.8379 A in the L emission spectrum of samarium, reported many years ago, has remained a puzzle. These have now been identified as EXAFS minima occurring at the L absorption edges of the respective elements. (author)

Samarium-153-EDTMP in the metastatic bone pain treatment

International Nuclear Information System (INIS)

Lins Filho, M.L.M.; Santos, A.O.; Nappi, A.P.B.; Meirelles, M.B.; Arouca, P.T.; Ramos, C.D.; Etchebehere, E.C.S.C.; Teixeira, L.C.; Netto Junior, N.R.; D'Ancona Cal; Camargo, E.E.

1997-01-01

Full text: Bone metastasis is the most reason of pain in prostate and mammary cancer patients. The Samarium-153-EDTMP has been showed as an alternative to the treatment of the metastasis bone pain. With the objective to evaluate the use of the Sm-153-EDTMP as a systemic therapy for the metastasis bone pain, 30 patients (19 male, 11 female, average age of 64,5 years) were studied. 19 patients with prostate cancer and 11 with mammary cancer. All the patients presented previous bone scintiscanning with multiple metastasis; interruption of the chemotherapy or radiotherapy for two or more weeks and leukocyte count higher than 2,000 leukocytes/mm 3 and platelets higher than 80,000/mm 3 . The patients were classified previously to the radioisotope therapy, as far the intensity of the pain in a scale from 0 to 10 is concerned. All the patients received 37 MBq/kg (1m Ci/kg) of weight of Sm-153-EDTMP by venous via. The evaluation 6 weeks after the therapy showed complete or partial pain relief in 22 patients (73,3%). Complete or partial pain relief has been obtained in 91,0% (10 in 11) of the patients with mammary cancer and in 62,2% (12 in 19) of the patients with prostate cancer. Transitory leukopenia (lower than 2,000 leukocytes/mm 3 ) and platelet count (lower than 80,000/mm 3 ) occurred in 33,3% of the patients. 8 patients (26,7%) did not responded to the therapy. The therapy with Samarium-153-EDTMP is a simple, safe and efficient method in the treatment of the bone pain caused by metastasis

Stress corrosion crack tip microstructure in nickel-based alloys

International Nuclear Information System (INIS)

Shei, S.A.; Yang, W.J.

1994-04-01

Stress corrosion cracking behavior of several nickel-base alloys in high temperature caustic environments has been evaluated. The crack tip and fracture surfaces were examined using Auger/ESCA and Analytical Electron Microscopy (AEM) to determine the near crack tip microstructure and microchemistry. Results showed formation of chromium-rich oxides at or near the crack tip and nickel-rich de-alloying layers away from the crack tip. The stress corrosion resistance of different nickel-base alloys in caustic may be explained by the preferential oxidation and dissolution of different alloying elements at the crack tip. Alloy 600 (UNS N06600) shows good general corrosion and intergranular attack resistance in caustic because of its high nickel content. Thermally treated Alloy 690 (UNS N06690) and Alloy 600 provide good stress corrosion cracking resistance because of high chromium contents along grain boundaries. Alloy 625 (UNS N06625) does not show as good stress corrosion cracking resistance as Alloy 690 or Alloy 600 because of its high molybdenum content

Dependence of samarium-soil interaction on samarium concentration: Implications for environmental risk assessment.

Science.gov (United States)

Ramírez-Guinart, Oriol; Salaberria, Aitor; Vidal, Miquel; Rigol, Anna

2018-03-01

The sorption and desorption behaviour of samarium (Sm), an emerging contaminant, was examined in soil samples at varying Sm concentrations. The obtained sorption and desorption parameters revealed that soil possessed a high Sm retention capacity (sorption was higher than 99% and desorption lower than 2%) at low Sm concentrations, whereas at high Sm concentrations, the sorption-desorption behaviour varied among the soil samples tested. The fractionation of the Sm sorbed in soils, obtained by sequential extractions, allowed to suggest the soil properties (pH and organic matter solubility) and phases (organic matter, carbonates and clay minerals) governing the Sm-soil interaction. The sorption models constructed in the present work along with the sorption behaviour of Sm explained in terms of soil main characteristics will allow properly assessing the Sm-soil interaction depending on the contamination scenario under study. Moreover, the sorption and desorption K d values of radiosamarium in soils were strongly correlated with those of stable Sm at low concentrations (r = 0.98); indicating that the mobility of Sm radioisotopes and, thus, the risk of radioactive Sm contamination can be predicted using data from low concentrations of stable Sm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Technical assessment of vanadium-base alloys for fusion reactor applications

International Nuclear Information System (INIS)

Gold, R.E.; Harrod, D.L.; Ammon, R.L.; Buckman, R.W. Jr.; Svedberg, R.C.

1978-01-01

A large data base has been compiled on vanadium-base alloys but the data base on any one alloy is quite limited. Great flexibility exists in the composition-microstructure-property relationship and this facilitates alloy optimization to meet diverse property requirements. Tensile properties and creep properties of existing alloys exceed likely requirements. Fatigue strength, including crack growth rate, is probably the most critical material property but no data exists for vanadium alloys. Swelling and irradiated ductility behavior look promising but require further evaluation. Vanadium alloy-liquid metal compatibility, particularly interstitial mass transfer, may be equally as critical as fatigue behavior; viability cannot be established with the existing data base. Fabricability must be given early consideration in alloys selection to guard against potentially serious problems in subsequent scale-up and production

The dynamics of the laser-induced metal-semiconductor phase transition of samarium sulfide (SmS)

International Nuclear Information System (INIS)

Kaempfer, Tino

2009-01-01

The present thesis is dedicated to the experimental study of the metal-semiconductor phase transition of samarium sulfide (SmS): Temperature- and time-resolved experiments on the characterization of the phase transition of mixed-valence SmS samples (M-SmS) are presented. The measurement of the dynamics of the laser-induced phase transition pursues via time-resolved ultrashort-time microscopy and by X-ray diffraction with sub-picosecond time resolution. The electronic and structural processes, which follow an excitation of M-SmS with infrared femtosecond laser pulses, are physically interpreted on the base of the results obtained in this thesis and model imaginations. [de

Corrosion and oxidation of vanadium-base alloys

International Nuclear Information System (INIS)

Loomis, B.A.; Wiggins, G.

1983-10-01

The corrosion of several V-base alloys on exposure at elevated temperatures to helium environments containing hydrogen and/or water vapor are presented. These results are utilized to discuss the consequences of the selection of certain radiation-damage resistant, V-base alloys for structural materials applications in a fusion reactor

Effective visible light-active nitrogen and samarium co-doped BiVO4 for the degradation of organic pollutants

International Nuclear Information System (INIS)

Wang, Min; Niu, Chao; Liu, Jun; Wang, Qianwu; Yang, Changxiu; Zheng, Haoyan

2015-01-01

Nitrogen and samarium co-doped BiVO 4 (N–xSm–BiVO 4 ) nanoparticles were synthesized using a sol–gel method with a corn stem template. The physicochemical properties of the resultant N–xSm–BiVO 4 particles were characterized using various methods: XPS, XRD, SEM, BET, and UV–Vis DRS analyses. The visible-light photocatalytic activity was successfully demonstrated by degrading a model dye, namely, methyl orange. The dopant content was optimized, and the nitrogen and samarium co-doped BiVO 4 extended the light absorption spectrum toward the visible region, significantly enhancing the photodegradation of the model dye. The Sm and N co-doped BiVO 4 exhibited the highest photocatalytic activity compared to materials with a single dopant or no dopant. The significantly enhanced photocatalytic activity of the N–Sm co-doped BiVO 4 under visible-light irradiation can be attributed to the synergistic effects of the nitrogen and samarium. - Highlights: • The N–Sm codoped BiVO 4 were synthesized using a sol–gel method with a corn stem template. • The N and Sm codoped BiVO 4 has excellent photocatalytic activity of methyl orange degradation. • The maximum activity was observed when the molar ratio of Sm/Bi was 1.0. • The high photocatalytic activity was caused by the synergistic effects between N doping and Sm doping

My Experience with Ti-Ni-Based and Ti-Based Shape Memory Alloys

Science.gov (United States)

Miyazaki, Shuichi

2017-12-01

The present author has been studying shape memory alloys including Cu-Al-Ni, Ti-Ni-based, and Ni-free Ti-based alloys since 1979. This paper reviews the present author's research results for the latter two materials since 1981. The topics on the Ti-Ni-based alloys include the achievement of superelasticity in Ti-Ni alloys through understanding of the role of microstructures consisting of dislocations and precipitates, followed by the contribution to the development of application market of shape memory effect and superelasticity, characterization of the R-phase and monoclinic martensitic transformations, clarification of the basic characteristics of fatigue properties, development of sputter-deposited shape memory thin films and fabrication of prototypes of microactuators utilizing thin films, development of high temperature shape memory alloys, and so on. The topics of Ni-free Ti-based shape memory alloys include the characterization of the orthorhombic phase martensitic transformation and related shape memory effect and superelasticity, the effects of texture, omega phase and adding elements on the martensitic transformation and shape memory properties, clarification of the unique effects of oxygen addition to induce non-linear large elasticity, Invar effect and heating-induced martensitic transformation, and so on.

Self-positioned thin Pb-alloy base electrode Josephson junction

International Nuclear Information System (INIS)

Kuroda, K.; Sato, K.

1986-01-01

A self-positioned thin (SPOT) Pb-alloy base electrode Josephson junction is developed. In this junction, a 50-nm thick Pb-alloy base electrode is restricted within the junction region on an Nb underlayer using a self-alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5 x 5 μm 2 ) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb-alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb-alloy base electrodes from the resistors

Nano-structureal and nano-chemical analysis of Ni-based alloy/low alloy steel dissimilar metal weld interfaces

International Nuclear Information System (INIS)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun

2012-01-01

The dissimilar metal joints welded between Ni-based alloy, Alloy 690 and low alloy steel, A533 Gr. B with Alloy 152 filler metal were characterized by using optical microscope, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and 3-dimensional atom probe tomography. It was found that in the weld root region, the weld was divided into several regions including unmixed zone in Ni-base alloy, fusion boundary, and heat-affected zone in the low alloy steel. The result of nanostructural and nanochemical analyses in this study showed the non-homogeneous distribution of elements with higher Fe but lower Mn, Ni and Cr in A533 Gr. B compared with Alloy 152, and the precipitation of carbides near the fusion boundary.

Nano-structureal and nano-chemical analysis of Ni-based alloy/low alloy steel dissimilar metal weld interfaces

Energy Technology Data Exchange (ETDEWEB)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

2012-06-15

The dissimilar metal joints welded between Ni-based alloy, Alloy 690 and low alloy steel, A533 Gr. B with Alloy 152 filler metal were characterized by using optical microscope, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and 3-dimensional atom probe tomography. It was found that in the weld root region, the weld was divided into several regions including unmixed zone in Ni-base alloy, fusion boundary, and heat-affected zone in the low alloy steel. The result of nanostructural and nanochemical analyses in this study showed the non-homogeneous distribution of elements with higher Fe but lower Mn, Ni and Cr in A533 Gr. B compared with Alloy 152, and the precipitation of carbides near the fusion boundary.

Lead and lead-based alloys as waste matrix materials

International Nuclear Information System (INIS)

Arustamov, A.E.; Ojovan, M.I.; Kachalov, M.B.

1999-01-01

Metals and alloys with relatively low melting temperatures such as lead and lead-based alloys are considered in Russia as prospective matrices for encapsulation of spent nuclear fuel in containers in preparation for final disposal in underground repositories. Now lead and lead-based alloys are being used for conditioning spent sealed radioactive sources at radioactive waste disposal facilities

Influence of S. mutans on base-metal dental casting alloy toxicity.

Science.gov (United States)

McGinley, E L; Dowling, A H; Moran, G P; Fleming, G J P

2013-01-01

We have highlighted that exposure of base-metal dental casting alloys to the acidogenic bacterium Streptococcus mutans significantly increases cellular toxicity following exposure to immortalized human TR146 oral keratinocytes. With Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), S. mutans-treated nickel-based (Ni-based) and cobalt-chromium-based (Co-Cr-based) dental casting alloys were shown to leach elevated levels of metal ions compared with untreated dental casting alloys. We targeted several biological parameters: cell morphology, viable cell counts, cell metabolic activity, cell toxicity, and inflammatory cytokine expression. S. mutans-treated dental casting alloys disrupted cell morphology, elicited significantly decreased viable cell counts (p casting alloys induced elevated levels of cellular toxicity compared with S. mutans-treated Co-Cr-based dental casting alloys. While our findings indicated that the exacerbated release of metal ions from S. mutans-treated base-metal dental casting alloys was the likely result of the pH reduction during S. mutans growth, the exact nature of mechanisms leading to accelerated dissolution of alloy-discs is not yet fully understood. Given the predominance of S. mutans oral carriage and the exacerbated cytotoxicity observed in TR146 cells following exposure to S. mutans-treated base-metal dental casting alloys, the implications for the long-term stability of base-metal dental restorations in the oral cavity are a cause for concern.

Production and properties of light-metal base amorphous alloys

International Nuclear Information System (INIS)

Inoue, Akihisa; Masumoto, Tsuyoshi

1993-01-01

Light-metal base alloys with high specific strength and good corrosion resistance were produced through amorphization of Al and Mg-based alloys. The amorphous phase is formed in rapidly solidified Al-TM-Ln and Mg-TM-Ln (TM=transition metal, Ln=lanthanide metal) alloys. The highest tensile strength (σ f ) reaches 1,330 MPa for the Al base and 830 MPa for the Mg base. Furthermore, the Mg-based alloys have a large glass-forming capacity which enables to produce an amorphous phase by a metallic mold casting method. The extrusion of the Al-based amorphous powders at temperatures above crystallization temperature caused the formation of high strength materials with finely mixed structure consisting of dispersed intermetallic compounds in an Al matrix. The highest values of σ f and fatigue limit are as high as 940 and 313 MPa, respectively, at room temperature and 520 and 165 MPa at 473 K. The extruded Al-Ni-Mm alloy has already been used as machine parts and subsequent further development as practical materials is expected by taking these advantages

The development of platinum-based alloys and their thermodynamic database

Directory of Open Access Journals (Sweden)

Cornish L.A.

2002-01-01

Full Text Available A series of quaternary platinum-based alloys have been demonstrated to exhibit the same two-phase structure as Ni-based superalloys and showed good mechanical properties. The properties of ternary alloys were a good indication that the quaternary alloys, with their better microstructure, will be even better. The quaternary alloy composition has been optimised at Pt84:Al11:Ru2:Cr3 for the best microstructure and hardness. Work has begun on establishing a thermodynamic database for Pt-Al-Ru-Cr alloys, and further work will be done to enhance the mechanical and oxidation properties of the alloys by adding small amounts of other elements to the base composition of Pt84:Al11:Ru2:Cr3.

Resonances of coherent population trapping in samarium vapours

International Nuclear Information System (INIS)

Kolachevsky, Nikolai N; Akimov, A V; Kiselev, N A; Papchenko, A A; Sorokin, Vadim N; Kanorskii, S I

2001-01-01

Resonances of coherent population trapping were detected in atomic vapours of the rare-earth element samarium. The coherent population trapping was produced by two external-cavity diode lasers (672 and 686 nm) in a Λ-system formed by the three levels of 154 Sm: the 4f 6 6s 2 ( 7 F 0 ) ground state, the first fine-structure 4f 6 6s 2 ( 7 F 1 ) sublevel of the ground state and the 4f 6 ( 7 F)6s6p( 3 P o ) 9 F o 1 upper level. The dependence of the spectral shapes and resonance contrasts on the polarisation of the laser beams and the direction of the applied magnetic field was studied. The obtained results were analysed. (nonlinear optical phenomena)

Grain Refinement of Permanent Mold Cast Copper Base Alloys

Energy Technology Data Exchange (ETDEWEB)

M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

2005-04-01

Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

Oxidation Behavior of TiAl-Based Alloy Modified by Double-Glow Plasma Surface Alloying with Cr-Mo

Science.gov (United States)

Wei, Xiangfei; Zhang, Pingze; Wang, Qiong; Wei, Dongbo; Chen, Xiaohu

2017-07-01

A Cr-Mo alloyed layer was prepared on a TiAl-based alloy using plasma surface alloying technique. The isothermal oxidation kinetics of the untreated and treated samples was examined at 850 °C. The microstructure and phase composition of the alloyed layer were analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray powder diffraction (XRD). The morphology and constituent of the oxide scales were also analyzed. The results indicated that the oxidation resistance of TiAl was improved significantly after the alloying treatment. The oxide scale eventually became a mixture of Al2O3, Cr2O3 and TiO2. The oxide scale was dense and integrated throughout the oxidation process. The improvement was mainly owing to the enhancing of scale adhesion and the preferential oxidation of aluminum brought by the alloying effect for TiAl-based alloy.

The systems lanthanum (cerium, samarium) nitrate-tetramethyl-ammonium nitrate-water

International Nuclear Information System (INIS)

Zhuravlev, E.F.; Khisaeva, D.A.; Semenova, Eh.B.

1984-01-01

The method of cross sections at 25 and 50 deg C has been applied to study solubility in the systems lanthanum nitrate-tetramethyl ammonium nitrate-water (1), cesium (3) nitrate-tetramethyl ammonium nitrate-water (2) and samarium nitrate-tetramethyl ammonium nitrate-water (3). Crystallization fields of congruently dissolving compounds with 1:3 ratio of salt components (in system 1) and 1:2 ratio (in systems 2 and 3) are found in the systems. New solid phases are separated preparatively and subjected to chemical, differential thermal and IR spectroscopic analyses. Compositions of formed compounds are compared with the compositions known for nitrates of other representatives of light lanthanides

Diffusion of hydrogen interstitials in Zr based AB2 and mischmetal based AB5 alloys

International Nuclear Information System (INIS)

Mani, N; Ravi, N; Ramaprabhu, S

2005-01-01

The Zr based AB 2 alloys ZrMnFe 0.5 Ni 0.5 , ZrMnFe 0.5 Co 0.5 and mischmetal (Mm) based AB 5 alloy MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 have been prepared and characterized by means of powder x-ray diffractograms. The hydrogen absorption kinetics of these alloys have been studied in the temperature and pressure ranges 450-650 0 C and 10-100 mbar respectively with a maximum H to host alloy formula unit ratio of 0.01, using a pressure reduction technique. The diffusion coefficient of the hydrogen interstitials has been determined from hydrogen absorption kinetics experiments. The dependence of the diffusion coefficient on the alloy content has been discussed. For Mm based MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 alloy, the diffusion coefficient is about an order of magnitude higher than that of the Zr based alloys

Effect of Microstructure and Alloy Chemistry on Hydrogen Embrittlement of Precipitation-Hardened Ni-Based Alloys

Science.gov (United States)

Obasi, G. C.; Zhang, Z.; Sampath, D.; Morana, Roberto; Akid, R.; Preuss, M.

2018-04-01

The sensitivity to hydrogen embrittlement (HE) has been studied in respect of precipitation size distributions in two nickel-based superalloys: Alloy 718 (UNS N07718) and Alloy 945X (UNS N09946). Quantitative microstructure analysis was carried out by the combination of scanning and transmission electron microscopy and energy dispersive x-ray spectroscopy (EDS). While Alloy 718 is mainly strengthened by γ″, and therefore readily forms intergranular δ phase, Alloy 945X has been designed to avoid δ formation by reducing Nb levels providing high strength through a combination of γ' and γ″. Slow strain rate tensile tests were carried out for different microstructural conditions in air and after cathodic hydrogen (H) charging. HE sensitivity was determined based on loss of elongation due to the H uptake in comparison to elongation to failure in air. Results showed that both alloys exhibited an elevated sensitivity to HE. Fracture surfaces of the H precharged material showed quasi-cleavage and transgranular cracks in the H-affected region, while ductile failure was observed toward the center of the sample. The crack origins observed on the H precharged samples exhibited quasi-cleavage with slip traces at high magnification. The sensitivity is slightly reduced for Alloy 718, by coarsening γ″ and reducing the overall strength of the alloy. However, on further coarsening of γ″, which promotes continuous decoration of grain boundaries with δ phase, the embrittlement index rose again indicating a change of hydrogen embrittlement mechanism from hydrogen-enhanced local plasticity (HELP) to hydrogen-enhanced decohesion embrittlement (HEDE). In contrast, Alloy 945X displayed a strong correlation between strength, based on precipitation size and embrittlement index, due to the absence of any significant formation of δ phase for the investigated microstructures. For the given test parameters, Alloy 945X did not display any reduced sensitivity to HE compared with

The systems cerium(3) (samarium) nitrate-quinoline nitrate-water

International Nuclear Information System (INIS)

Khisaeva, D.A.; Zhuravlev, E.F.; Semenova, Eh.B.

1982-01-01

Using the method of cross sections at 25 and 50 deg C the solubility in the systems cerium (3) nitrate-quinoline nitrate-water and samarium nitrate-quinoline nitrate-water has been studied. It is established that in the systems during chemical interaction of components congruently melting compounds of the composition: Ce(NO 3 ) 2 x2[C 9 H 7 NxHNO 3 ]x6H 2 O and Sm(NO 3 ) 3 x2[C 9 H 7 NxHNO 3 ]x2H 2 O are formed. New solid phases are separated preparatively and are subjected to chemical, differential thermal and IR spectroscopic analyses. The investigation results are compared with similar ones for nitrates of other representatives of lanthanide group

Body composition analysis by DEXA by using dynamically changing samarium filtration

DEFF Research Database (Denmark)

Gotfredsen, Arne; Baeksgaard, L; Hilsted, J

1997-01-01

Dual-energy X-ray absorptiometry (DEXA) has a high accuracy for body composition analysis but is influenced by beam hardening and other error sources in the extremes of measurement. To compensate for beam hardening, the Norland XR-36 introduces a dynamically changing samarium filtration system......). Scans of six healthy volunteers covered with combinations of beef and lard (approximately 5-15 kg) showed a good agreement (r = 0.99) between reference and DEXA values of added soft tissue mass and fat percentage. We conclude that the DEXA method (and, in particular, the Norland XR-36 using dynamic...

Ti-Ni-based shape memory alloys as smart materials

International Nuclear Information System (INIS)

Otsuka, K.; Xu, Y.; Ren, X.

2003-01-01

Smart materials consist of three principal materials, ferroelectrics, shape memory alloys (SMA) and electro-active polymers (EAP). Among these SMAs, especially Ti-Ni-based alloys are important, since only they can provide large recoverable strains and high recovery stress. In the present paper the unique characteristics of Ti-Ni-based shape memory alloys are reviewed on an up-to-date basis with the aim of their applications to smart materials and structures. (orig.)

Fe-Mn-Si based shape memory alloys

International Nuclear Information System (INIS)

Hsu, T.Y.

2000-01-01

Characteristics of martensitic transformation fcc(γ)→hcp(ε) in Fe-Mn-Si based alloys are briefly reviewed. By analyzing the influences of constituents and treatments on shape memory effect (SME) in Fe-Mn-Si, the main factors controlling SME are summarized as austenite strengthening, stacking fault energy (probability) and antiferromagnetic temperature. Contribution of thermomechanical training to SME is introduced. The Fe-Mn-Si-RE (rare earth elements) and Fe-Mn-Si-Cr-N alloys are recommended as two novel shape memory alloys with superior SME. (orig.)

TiAu based shape memory alloys for high temperature applications

International Nuclear Information System (INIS)

Wadood, Abdul; Yamabe-Mitarai, Yoko; Hosoda, Hideki

2014-01-01

TiAu (equiatomic) exhibits phase transformaion from B2 (ordered bcc) to thermo-elastic orthorhombic B19 martensite at about 875K and thus TiAu is categorized as high temperature shape memory alloy. In this study, recent research and developments related to TiAu based high temperature shape memory alloys will be discussed in the Introduction part. Then some results of our research group related to strengthening of TiAu based high temperature shape memory alloys will be presented. Potential of TiAu based shape memory alloys for high temperature shape memory materials applications will also be discussed

Effective visible light-active nitrogen and samarium co-doped BiVO{sub 4} for the degradation of organic pollutants

Energy Technology Data Exchange (ETDEWEB)

Wang, Min; Niu, Chao [College of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110165 (China); Liu, Jun, E-mail: minwang62@msn.com [Shenyang Military General Hospital, Shenyang 110016 (China); Wang, Qianwu; Yang, Changxiu; Zheng, Haoyan [College of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110165 (China)

2015-11-05

Nitrogen and samarium co-doped BiVO{sub 4} (N–xSm–BiVO{sub 4}) nanoparticles were synthesized using a sol–gel method with a corn stem template. The physicochemical properties of the resultant N–xSm–BiVO{sub 4} particles were characterized using various methods: XPS, XRD, SEM, BET, and UV–Vis DRS analyses. The visible-light photocatalytic activity was successfully demonstrated by degrading a model dye, namely, methyl orange. The dopant content was optimized, and the nitrogen and samarium co-doped BiVO{sub 4} extended the light absorption spectrum toward the visible region, significantly enhancing the photodegradation of the model dye. The Sm and N co-doped BiVO{sub 4} exhibited the highest photocatalytic activity compared to materials with a single dopant or no dopant. The significantly enhanced photocatalytic activity of the N–Sm co-doped BiVO{sub 4} under visible-light irradiation can be attributed to the synergistic effects of the nitrogen and samarium. - Highlights: • The N–Sm codoped BiVO{sub 4} were synthesized using a sol–gel method with a corn stem template. • The N and Sm codoped BiVO{sub 4} has excellent photocatalytic activity of methyl orange degradation. • The maximum activity was observed when the molar ratio of Sm/Bi was 1.0. • The high photocatalytic activity was caused by the synergistic effects between N doping and Sm doping.

Physical and welding metallurgy of Gd-enriched austenitic alloys for spent nuclear fuel applications. Part II, nickel base alloys

International Nuclear Information System (INIS)

Mizia, Ronald E.; Michael, Joseph Richard; Williams, David Brian; Dupont, John Neuman; Robino, Charles Victor

2004-01-01

The physical and welding a metallurgy of gadolinium- (Gd-) enriched Ni-based alloys has been examined using a combination of differential thermal analysis, hot ductility testing. Varestraint testing, and various microstructural characterization techniques. Three different matrix compositions were chosen that were similar to commercial Ni-Cr-Mo base alloys (UNS N06455, N06022, and N06059). A ternary Ni-Cr-Gd alloy was also examined. The Gd level of each alloy was ∼2 wt-%. All the alloys initiated solidification by formation of primary austenite and terminated solidification by a Liquid γ + Ni 5 Gd eutectic-type reaction at ∼1270 C. The solidification temperature ranges of the alloys varied from ∼100 to 130 C (depending on alloy composition). This is a substantial reduction compared to the solidification temperature range to Gd-enriched stainless steels (360 to 400 C) that terminate solidification by a peritectic reaction at ∼1060 C. The higher-temperature eutectic reaction that occurs in the Ni-based alloys is accompanied by significant improvements in hot ductility and solidification cracking resistance. The results of this research demonstrate that Gd-enriched Ni-based alloys are excellent candidate materials for nuclear criticality control in spent nuclear fuel storage applications that require production and fabrication of large amounts of material through conventional ingot metallurgy and fusion welding techniques

The development of platinum-based alloys and their thermodynamic database

OpenAIRE

Cornish L.A.; Hohls J.; Hill P.J.; Prins S.; Süss R.; Compton D.N.

2002-01-01

A series of quaternary platinum-based alloys have been demonstrated to exhibit the same two-phase structure as Ni-based superalloys and showed good mechanical properties. The properties of ternary alloys were a good indication that the quaternary alloys, with their better microstructure, will be even better. The quaternary alloy composition has been optimised at Pt84:Al11:Ru2:Cr3 for the best microstructure and hardness. Work has begun on establishing a thermodynamic database for Pt-Al-Ru-Cr ...

Ferrites Ni0,5Zn0,5Fe2O4 doped with samarium: structural analysis, morphological and electromagnetic

International Nuclear Information System (INIS)

Costa, A.C.F.M.; Diniz, A.P.; Viana, K.M.S.; Cornejo, D.R.; Kiminami, R.H.G.A.

2010-01-01

This paper proposes to investigate the sintering at 1200 deg C/2h of Ni 0.5 Zn 0.5 Fe 2-x Sm x O 4 ferrite doped with 0.05; 0.075 e 0.1 mol of Sm synthesized by combustion reaction to evaluate the performance materials as absorbers of electromagnetic radiation. The influence of the concentration of samarium on the structure, morphology and electromagnetic properties of ferrites was studied. The resulting samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), magnetic measurements and reflectivity measurements in the frequency range between 8-12 GHz. The results showed that increasing the concentration of samarium caused a decrease in particle size of the samples, encouraging, therefore, to obtain materials with better values of magnetization and reflectivity, allowing for use as absorbers in narrow-band frequency between 9-10 GHz. (author)

Calculations of hydrogen diffusivity in Zr-based alloys: Influence of alloying elements and effect of stress

International Nuclear Information System (INIS)

Yu, J.; Jiang, C.; Zhang, Y.

2017-01-01

This report summarizes the progress on modeling hydrogen diffusivity in Zr-based alloys. The presence of hydrogen (H) can detrimentally affect the mechanical properties of many metals and alloys. To mitigate these detrimental effects requires fundamental understanding of the thermodynamics and kinetics governing H pickup and hydride formation. In this work, we focus on H diffusion in Zr-based alloys by studying the effects of alloying elements and stress, factors that have been shown to strongly affect H pickup and hydride formation in nuclear fuel claddings. A recently developed accelerated kinetic Monte Carlo method is used for the study. It is found that for the alloys considered here, H diffusivity depends weakly on composition, with negligible effect at high temperatures in the range of 600-1200 K. Therefore, the small variation in compositions of these alloys is likely not a major cause of the very different H pickup rates. In contrast, stress strongly affects H diffusivity. This effect needs to be considered for studying hydride formation and delayed hydride cracking.

Calculations of hydrogen diffusivity in Zr-based alloys: Influence of alloying elements and effect of stress

Energy Technology Data Exchange (ETDEWEB)

Yu, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-06-01

This report summarizes the progress on modeling hydrogen diffusivity in Zr-based alloys. The presence of hydrogen (H) can detrimentally affect the mechanical properties of many metals and alloys. To mitigate these detrimental effects requires fundamental understanding of the thermodynamics and kinetics governing H pickup and hydride formation. In this work, we focus on H diffusion in Zr-based alloys by studying the effects of alloying elements and stress, factors that have been shown to strongly affect H pickup and hydride formation in nuclear fuel claddings. A recently developed accelerated kinetic Monte Carlo method is used for the study. It is found that for the alloys considered here, H diffusivity depends weakly on composition, with negligible effect at high temperatures in the range of 600-1200 K. Therefore, the small variation in compositions of these alloys is likely not a major cause of the very different H pickup rates. In contrast, stress strongly affects H diffusivity. This effect needs to be considered for studying hydride formation and delayed hydride cracking.

Cerium Titanate Nano dispersoids in Ni-base ODS Alloy

Energy Technology Data Exchange (ETDEWEB)

Kang, Suk Hoon; Chun, Young-Bum; Rhee, Chang-Kyu; Jang, Jinsung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chung, Hee-Suk [Korea Basic Science Institute, Jeonju (Korea, Republic of)

2016-10-15

Oxide-dispersion-strengthened (ODS) nickel-base alloys have potential for use in rather demanding elevated-temperature environments, such as aircraft turbine engines, heat exchanger of nuclear reactor. For improved high temperature performance, several ODS alloys were developed which possess good elevated temperature strength and over-temperature capacity plus excellent static oxidation resistance. The high temperature strength of ODS alloys is due to the presence of a uniform dispersion of fine, inert particles. Ceria mixed oxides have been studied because of their application potential in the formation of nanoclusters. By first principle study, it was estimated that the formation energy of the Ce-O dimer with voids in the nickel base alloy is lower than other candidates. The result suggests that the dispersion of the Ceria mixed oxides can suppress the voiding or swelling behavior of nickel base alloy during neutron irradiation. In this study, the evolution of cerium titanate nano particles was investigated using in-situ TEM. It was found that the Ce{sub 2}Ti{sub 3}O{sub 9} phase was easily formed rather than remain as CeO{sub 2} during annealing; Ti was effective to form the finer oxide particles. Ce{sub 2}Ti{sub 3}O{sub 9} is expected to do the great roll as dispersoids in Ni-base alloy, contribute to achieve the better high temperature property, high swelling resistance during neutron radiation.

Electrochemical hydrogen storage alloys and batteries fabricated from Mg containing base alloys

Science.gov (United States)

Ovshinsky, Stanford R.; Fetcenko, Michael A.

1996-01-01

An electrochemical hydrogen storage material comprising: (Base Alloy).sub.a M.sub.b where, Base Alloy is an alloy of Mg and Ni in a ratio of from about 1:2 to about 2:1, preferably 1:1; M represents at least one modifier element chosen from the group consisting of Co, Mn, Al, Fe, Cu, Mo, W, Cr, V, Ti, Zr, Sn, Th, Si, Zn, Li, Cd, Na, Pb, La, Mm, and Ca; b is greater than 0.5, preferably 2.5, atomic percent and less than 30 atomic percent; and a+b=100 atomic percent. Preferably, the at least one modifier is chosen from the group consisting of Co, Mn, Al, Fe, and Cu and the total mass of the at least one modifier element is less than 25 atomic percent of the final composition. Most preferably, the total mass of said at least one modifier element is less than 20 atomic percent of the final composition.

Corrosion resistance of Fe-based amorphous alloys

International Nuclear Information System (INIS)

Botta, W.J.; Berger, J.E.; Kiminami, C.S.; Roche, V.; Nogueira, R.P.; Bolfarini, C.

2014-01-01

Highlights: ► We report corrosion properties of Fe-based amorphous alloys in different media. ► The Cr-containing alloys had corrosion resistance close to that of Pt in all media. ► The wide range of electrochemical stability is relevant in many industrial domains. -- Abstract: Fe-based amorphous alloys can be designed to present an attractive combination of properties with high corrosion resistance and high mechanical strength. Such properties are clearly adequate for their technological use as coatings, for example, in steel pipes. In this work, we studied the corrosion properties of amorphous ribbons of the following Fe-based compositions: Fe 66 B 30 Nb 4 , [(Fe 0.6 Co 0.4 ) 0.75 B 0.2 Si 0.05 ] 96 Nb 4 , [(Fe 0.7 Co 0.3 ) 0.75 B 0.2 Si 0.05 ] 96 Nb 4 , Fe 56 Cr 23 Ni 5.7 B 16 , Fe 53 Cr 22 Ni 5.6 B 19 and Fe 50 Cr 22 Ni 5.4 B 23 . The ribbons were obtained by rapid solidification using the melt-spinning process, and were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and optical (OM) and scanning electron microscopy (SEM). The corrosion properties were evaluated by corrosion potential survey and potentiodynamic polarization. The Cr containing alloys, that is the FeCrNiB type of alloys, showed the best corrosion resistance properties with the formation of a stable passive film that ensured a very large passivation plateau

LASER CLADDING ON ALUMINIUM BASE ALLOYS

OpenAIRE

Pilloz , M.; Pelletier , J.; Vannes , A.; Bignonnet , A.

1991-01-01

laser cladding is often performed on iron or titanium base alloys. In the present work, this method is employed on aluminum alloys ; nickel or silicon are added by powder injection. Addition of silicon leads to sound surface layers, but with moderated properties, while the presence of nickel induces the formation of hard intermetallic compounds and then to an attractive hardening phenomena ; however a recovery treatment has to be carried out, in order to eliminate porosity in the near surface...

Supercritical water corrosion of high Cr steels and Ni-base alloys

International Nuclear Information System (INIS)

Jang, Jin Sung; Han, Chang Hee; Hwang, Seong Sik

2004-01-01

High Cr steels (9 to 12% Cr) have been widely used for high temperature high pressure components in fossil power plants. Recently the concept of SCWR (supercritical water-cooled reactor) has aroused a keen interest as one of the next generation (Generation IV) reactors. Consequently Ni-base (or high Ni) alloys as well as high Cr steels that have already many experiences in the field are among the potential candidate alloys for the cladding or reactor internals. Tentative inlet and outlet temperatures of the anticipated SCWR are 280 and 510 .deg. C respectively. Among many candidate alloys there are austenitic stainless steels, Ni base alloys, ODS alloys as well as high Cr steels. In this study the corrosion behavior of the high Cr steels and Ni base (or high Ni) alloys in the supercritical water were investigated. The corrosion behavior of the unirradiated base metals could be used in the near future as a guideline for the out-of-pile or in-pile corrosion evaluation tests

Characterization of the microstructure in Mg based alloy

KAUST Repository

Kutbee, Arwa T

2013-06-01

The cast products Mg–Sn based alloys are promising candidates for automobile industries, since they provide a cheap yet thermally stable alternative to existing alloys. One drawback of the Mg–Sn based alloys is their insufficient hardness. The hardenability can be improved by engineering the microstructure through additions of Zn to the base alloy and selective aging conditions. Therefore, detailed knowledge about the microstructural characteristics and the role of Zn to promote precipitation hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT was employed to obtain precise chemical information on the distribution of Zn in the microstructure. It was found from microstructural studies that different precipitates with varying sizes and phases were present; lath-shaped precipitates of the Mg2Sn phase have an incoherent interface with the matrix, unlike the lath-shaped MgZn2 precipitates. Furthermore, nano-sized precipitates dispersed in the microstructure with short-lath morphology can either be enriched with Sn or Zn. On the other hand, APT analysis revealed the strong repulsion between Sn and Zn atoms in a portion of the analysis volume. However, larger reconstruction volume required to identify the role of Zn is still limited to the optimization of specimen preparation.

Fracture assessment for a dissimilar metal weld of low alloy steel and Ni-base alloy

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Takuya, E-mail: takuya4.ogawa@toshiba.co.jp [Toshiba Corporation Power Systems Company, Power and Industrial Systems Research and Development Center, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Itatani, Masao; Saito, Toshiyuki; Hayashi, Takahiro; Narazaki, Chihiro; Tsuchihashi, Kentaro [Toshiba Corporation Power Systems Company, Power and Industrial Systems Research and Development Center, 8, Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan)

2012-02-15

Recently, instances of SCC in Ni-base alloy weld metal of light water reactor components have been reported. Despite the possibility of propagation of SCC crack to the fusion line between low alloy steel (LAS) of pressure vessel and Ni-base alloy of internal structure, a fracture assessment method of dissimilar metal welded joint has not been established. The objective of this study is to investigate a fracture mode of dissimilar metal weld of LAS and Ni-base alloy for development of a fracture assessment method for dissimilar metal weld. Fracture tests were conducted using two types of dissimilar metal weld test plates with semi-elliptical surface crack. In one of the test plates, the fusion line lies around the surface points of the surface crack and the crack tips at the surface points have intruded into LAS. Material ahead of the crack tip at the deepest point is Ni-base alloy. In the other, the fusion line lies around the deepest point of the surface crack and the crack tip at the deepest point has intruded into LAS. Material ahead of the crack tip at the deepest point is LAS. The results of fracture tests using the former type of test plate reveal that the collapse load considering the proportion of ligament area of each material gives a good estimation for fracture load. That is, fracture assessment based on plastic collapse mode is applicable to the former type of test plate. It is also understood that a fracture assessment method based on the elastic-plastic fracture mode is suitable for the latter type of test plate.

Acoustic properties of TiNiMoFe base alloys

International Nuclear Information System (INIS)

Gyunter, V.Eh.; Chernyshev, V.I.; Chekalkin, T.L.

2000-01-01

The regularity of changing the acoustic properties of the TiNi base alloys in dependence on the alloy composition and impact temperature is studied. It is shown that the oscillations of the TiNiMoFe base alloys within the temperature range of the B2 phase existence and possible appearance of the martensite under the load differ from the traditional materials oscillations. After excitation of spontaneous oscillations within the range of M f ≤ T ≤ M d there exists the area of long-term and low-amplitude low-frequency acoustic oscillations. It is established that free low-frequency oscillations of the TH-10 alloy sample are characterized by the low damping level in the given temperature range [ru

Microstructures and oxidation behavior of some Molybdenum based alloys

Energy Technology Data Exchange (ETDEWEB)

Ray, Pratik Kumar [Iowa State Univ., Ames, IA (United States)

2011-01-01

The advent of Ni based superalloys revolutionized the high temperature alloy industry. These materials are capable of operating in extremely harsh environments, comprising of temperatures around 1050 C, under oxidative conditions. Demands for increased fuel efficiency, however, has highlighted the need for materials that can be used under oxidative conditions at temperatures in excess of 1200 C. The Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that melt in the 1250 - 1450 C, resulting in softening of the alloys above 1000 C. Therefore, recent research directions have been skewed towards exploring and developing newer alloy systems. This thesis comprises a part of such an effort. Techniques for rapid thermodynamic assessments were developed and applied to two different systems - Mo-Si alloys with transition metal substitutions (and this forms the first part of the thesis) and Ni-Al alloys with added components for providing high temperature strength and ductility. A hierarchical approach towards alloy design indicated the Mo-Ni-Al system as a prospective candidate for high temperature applications. Investigations on microstructures and oxidation behavior, under both isothermal and cyclic conditions, of these alloys constitute the second part of this thesis. It was seen that refractory metal systems show a marked microstructure dependence of oxidation.

Nanocrystalline Al-based alloys - lightweight materials with attractive mechanical properties

International Nuclear Information System (INIS)

Latuch, J; Cieslak, G; Dimitrov, H; Krasnowski, M; Kulik, T

2009-01-01

In this study, several ways of bulk nanocrystalline Al-based alloys' production by high-pressure compaction of powders were explored. The effect of chemical composition and compaction parameters on the structure, quality and mechanical properties of the bulk samples was studied. Bulk nanocrystalline Al-Mm-Ni-(Fe,Co) alloys were prepared by ball-milling of amorphous ribbons followed by consolidation. The maximum microhardness (540 HV0.1) was achieved for the samples compacted at 275 deg. C under 7.7 GPa (which resulted in an amorphous bulk) and nanocrystallised at 235 deg. C for 20 min. Another group of the produced materials were bulk nanocrystalline Al-Si-(Ni,Fe)-Mm alloys obtained by ball-milling of nanocrystalline ribbons and consolidation. The hardness of these samples achieved the value five times higher (350HV) than that of commercial 4xxx series Al alloys. Nanocrystalline Al-based alloys were also prepared by mechanical alloying followed by hot-pressing. In this group of materials, there were Al-Fe alloys containing 50-85 at.% of Al and ternary or quaternary Al-Fe-(Ti, Si, Ni, Mg, B) alloys. Microhardness of these alloys was in the range of 613 - 1235 HV0.2, depending on the composition.

Effect of alloying elements on the stability of Ni2M in Alloy690 based upon thermodynamic calculation

International Nuclear Information System (INIS)

Horiuchi, Toshiaki; Kuwano, Kazuhiro; Satoh, Naohiro

2012-01-01

Some researchers recently point out that Ni based alloys used in nuclear power plants have the ordering tendency, which is a potential to decrease mechanical properties within the expected lifetime of the plants. In the present study, authors evaluated the effect of 8 alloying elements on the ordering tendency in Alloy690 based upon thermodynamic calculation by Thermo-Calc. It is clarified that the additive amount of Fe, Cr, Ti and Si, particularly Fe and Cr, was influential for the stability of Ni 2 M, while that of Mn, Cu, B and C had almost no effect for that. Authors therefore designed the Ni 2 M stabilized alloy by no addition of Fe in Alloy690. Ni 2 M is estimated to be stable even at 773 K in the Ni 2 M stabilized alloy. The influence by long range ordering or precipitating of Ni 2 M in Alloy690 for mechanical properties or SCC susceptibility is expected to be clarified by the sample obtained in the present study. (author)

Porous Nb-Ti based alloy produced from plasma spheroidized powder

OpenAIRE

Li, Qijun; Zhang, Lin; Wei, Dongbin; Ren, Shubin; Qu, Xuanhui

2017-01-01

Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20–110 μm. With the decr...

Salt Fog Testing Iron-Based Amorphous Alloys

International Nuclear Information System (INIS)

Rebak, Raul B.; Aprigliano, Louis F.; Day, S. Daniel; Farmer, Joseph C.

2007-01-01

Iron-based amorphous alloys are hard and highly corrosion resistant, which make them desirable for salt water and other applications. These alloys can be produced as powder and can be deposited as coatings on any surface that needs to be protected from the environment. It was of interest to examine the behavior of these amorphous alloys in the standard salt-fog testing ASTM B 117. Three different amorphous coating compositions were deposited on 316L SS coupons and exposed for many cycles of the salt fog test. Other common engineering alloys such as 1018 carbon steel, 316L SS and Hastelloy C-22 were also tested together with the amorphous coatings. Results show that amorphous coatings are resistant to rusting in salt fog. Partial devitrification may be responsible for isolated rust spots in one of the coatings. (authors)

Determination of micro amounts of samarium and europium by analogue derivative spectrophotometry

International Nuclear Information System (INIS)

Ishii, H.; Satoh, K.

1982-01-01

Derivative spectrophotometry using the analogue differentiation circuit was applied to the determination of samarium and europium at ppm levels. By measuring the second or the fourth derivative spectra of the characteristic absorption bands of both the rare earth ions around 400 nm, they can be determined directly and selectively in the presence of large amounts of most other rare earths without any prior separation. Further, aptly selecting conditions for the measurement of the derivative spectra, the simultaneous determination of both the rare earth elements was feasible. The principle and the characteristics of analogue derivative spectrophotometry are also described. (orig.) [de

Formation and Applications of Bulk Glassy Alloys in Late Transition Metal Base System

International Nuclear Information System (INIS)

Inoue, Akihisa; Shen Baolong

2006-01-01

This paper reviews our recent results of the formation, fundamental properties, workability and applications of late transition metal (LTM) base bulk glassy alloys (BGAs) developed since 1995. The BGAs were obtained in Fe-(Al,Ga)-(P,C,B,Si), Fe-(Cr,Mo)-(C,B), Fe-(Zr,Hf,Nb,Ta)-B, Fe-Ln-B(Ln=lanthanide metal), Fe-B-Si-Nb and Fe-Nd-Al for Fe-based alloys, Co-(Ta,Mo)-B and Co-B-Si-Nb for Co-based alloys, Ni-Nb-(Ti,Zr)-(Co,Ni) for Ni-based alloys, and Cu-Ti-(Zr,Hf), Cu-Al-(Zr,Hf), Cu-Ti-(Zr,Hf)-(Ni,Co) and Cu-Al-(Zr,Hf)-(Ag,Pd) for Cu-based alloys. These BGAs exhibit useful properties of high mechanical strength, large elastic elongation and high corrosion resistance. In addition, Fe- and Co-based glassy alloys have good soft magnetic properties which cannot be obtained for amorphous and crystalline type magnetic alloys. The Fe- and Ni-based BGAs have already been used in some application fields. These LTM base BGAs are promising as new metallic engineering materials

Effects of alloying elements on nodular and uniform corrosion resistance of zirconium-based alloys

International Nuclear Information System (INIS)

Abe, Katsuhiro

1992-01-01

The effects of alloying and impurity elements (tin, iron, chromium, nickel, niobium, tantalum, oxygen, aluminum, carbon, nitrogen, silicon, and phosphorus) on the nodular and uniform corrosion resistance of zirconium-based alloys were studied. The improving effect of iron, nickel and niobium in nodular corrosion resistance were observed. The uniform corrosion resistance was also improved by nickel, niobium and tantalum. The effects of impurity elements, nitrogen, aluminum and phosphorus were negligibly small but increasing the silicon content seemed to improve slightly the uniform corrosion resistance. Hydrogen pick-up fraction were not changed by alloying and impurity elements except nickel. Nickel addition increased remarkably hydrogen pick-up fraction. Although the composition of secondary precipitates changed with contents of alloying elements, the correlation of composition of secondary precipitates to corrosion resistance was not observed. (author)

Indentation creep behaviors of amorphous Cu-based composite alloys

Science.gov (United States)

Song, Defeng; Ma, Xiangdong; Qian, Linfang

2018-04-01

This work reports the indentation creep behaviors of two Si2Zr3/amorphous Cu-based composite alloys utilizing nanoindentation technique. By analysis with Kelvin model, the retardation spectra of alloys at different positions, detached and attached regions to the intermetallics, were deduced. For the indentation of detached regions to Si2Zr3 intermetallics in both alloys, very similarity in creep displacement can be observed and retardation spectra show a distinct disparity in the second retardation peak. For the indentation of detached regions, the second retardation spectra also display distinct disparity. At both positions, the retardation spectra suggest that Si elements may lead to the relatively dense structure in the amorphous matrix and to form excessive Si2Zr3 intermetallics which may deteriorate the plastic deformation of current Cu-based composite alloys.

Alloying behavior of iron, gold and silver in AlCoCrCuNi-based equimolar high-entropy alloys

International Nuclear Information System (INIS)

Hsu, U.S.; Hung, U.D.; Yeh, J.W.; Chen, S.K.; Huang, Y.S.; Yang, C.C.

2007-01-01

High-entropy alloys are newly developed alloys that are composed, by definition, of at least five principal elements with concentrations in the range of 5-35 at.%. Therefore, the alloying behavior of any given principal element is significantly affected by all the other principal elements present. In order to elucidate this further, the influence of iron, silver and gold addition on the microstructure and hardness of AlCoCrCuNi-based equimolar alloys has been examined. The as-cast AlCoCrCuNi base alloy is found to have a dendritic structure, of which only solid solution FCC and BCC phases can be observed. The BCC dendrite has a chemical composition close to that of the nominal alloy, with a deficiency in copper however, which is found to segregate and form a FCC Cu-rich interdendrite. The microstructure of the iron containing alloys is similar to that of the base alloy. It is found that both of these aforementioned alloys have hardnesses of about 420 HV, which is equated to their similar microstructures. The as-cast ingot forms two layers of distinct composition with the addition of silver. These layers, which are gold and silver in color, are determined to have a hypoeutectic Ag-Cu composition and a multielement mixture of the other principal elements, respectively. This indicates the chemical incompatibility of silver with the other principal elements. The hardnesses of the gold (104 HV) and silver layers (451 HV) are the lowest and highest of the alloy systems studied. This is attributed to the hypoeutectic Ag-Cu composition of the former and the reduced copper content of the latter. Only multielement mixtures, i.e. without copper segregation, form in the gold containing alloy. Thus, it may be said that gold acts as a 'mixing agent' between copper and the other elements. Although several of the atom pairs in the gold containing alloy have positive enthalpies, thermodynamic considerations show that the high entropy contribution is sufficient to counterbalance

Segregation in welded nickel-base alloys

International Nuclear Information System (INIS)

Akhtar, J.I.; Shoaib, K.A.; Ahmad, M.; Shaikh, M.A.

1990-05-01

Segregation effects have been investigated in nickel-base alloys monel 400, inconel 625, hastelloy C-276 and incoloy 825, test welded under controlled conditions. Deviations from the normal composition have been observed to varying extents in the welded zone of these alloys. Least effect of this type occurred in Monel 400 where the content of Cu increased in some of the areas. Enhancement of Al and Ti has been found over large areas in the other alloys which has been attributed to the formation of low melting slag. Another common feature is the segregation of Cr, Fe or Ti, most likely in the form of carbides. Enrichment of Al, Ti, Nb, Mb, Mo, etc., to different amounts in some of the areas of these materials is in- terpretted in terms of the formation of gamma prime precipitates or of Laves phases. (author)

The development of cobalt-base alloy ball bearing

International Nuclear Information System (INIS)

Yu Xinshui; Chen Jianting; Wang Zaishu; Wang Ximei; Huang Chongming.

1986-01-01

The main technologies and experiences in developing a Cobalt-base alloy ball bearing are described. In the hardfacing of bearing races, a lower-hardness alloy of type St-6 is used rather than an alloy with hardness similar to that of the ball and finally the hardness of race is increased to match that of the ball by heat treatment. This improvement has certain advantages. The experience of whole developing technology indicates that strict control of the technology in the bearing-race hardfacing is the key problem in the quality assurance of bearings

Porous Nb-Ti based alloy produced from plasma spheroidized powder

Directory of Open Access Journals (Sweden)

Qijun Li

Full Text Available Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20–110 μm. With the decrease of particle size, a transformation from typical dendrite solidification structure to fine cell microstructure occurs. The surface of the spheroidized powder is coated by a layer of oxides consisting mainly of TiO2 and Nb2O5. Probabilities of sinter-neck formation and particle coalescence increases with increasing sintering temperature. Porous skeleton with relatively homogeneous pore distribution and open pore channel is formed after vacuum sintering at 1700 °C, and the porosity is 32%. The sintering kinetic analysis indicates that grain boundary diffusion is the primary mass transport mechanism during sintering process. Keywords: Powder metallurgy, Nb-Ti based alloy, Porous material, Mechanical alloying, Plasma spheroidizing, Solidification microstructure

Improved Mg-based alloys for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Sapru, K.; Ming, L.; Stetson, N.T.; Evans, J. [Energy Conversion Devices, Inc., Troy, MI (United States)

1998-08-01

The overall objective of this on-going work is to develop low temperature alloys capable of reversibly storing at least 3 wt.% hydrogen, allowing greater than for 2 wt.% at the system level which is required by most applications. Surface modification of Mg can be used to improve its H-sorption kinetics. The authors show here that the same Mg-transition metal-based multi-component alloy when prepared by melt-spinning results in a more homogeneous materials with a higher plateau pressure as compared to preparing the material by mechanical grinding. They have also shown that mechanically alloyed Mg{sub 50}Al{sub 45}Zn{sub 5} results in a sample having a higher plateau pressure.

Melting and casting of FeAl-based cast alloy

Energy Technology Data Exchange (ETDEWEB)

Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

1998-11-01

The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

Analysis of iron-base alloys by low-wattage glow discharge emission spectrometry

International Nuclear Information System (INIS)

Wagatsuma, K.; Hirokawa, K.

1984-01-01

Several iron-base alloys were investigated by low-wattage glow discharge emission spectrometry. The emission intensity principally depended on the sputtering parameters of constituent elements in the alloy. However, in the case of chromium, stable and firm oxides formed on the surface influencing the yield of ejected atoms. This paper discusses the relation between the sputtering parameters in Fe-Ni, Fe-Cr, and Fe-Co alloys and their relative emission intensities. Additionally, quantitative analysis was performed for some ternary iron-base alloys and commercial stainless steels with the calibration factors of binary alloy systems

The development of additive manufacturing technique for nickel-base alloys: A review

Science.gov (United States)

Zadi-Maad, Ahmad; Basuki, Arif

2018-04-01

Nickel-base alloys are an attractive alloy due to its excellent mechanical properties, a high resistance to creep deformation, corrosion, and oxidation. However, it is a hard task to control performance when casting or forging for this material. In recent years, additive manufacturing (AM) process has been implemented to replace the conventional directional solidification process for the production of nickel-base alloys. Due to its potentially lower cost and flexibility manufacturing process, AM is considered as a substitute technique for the existing. This paper provides a comprehensive review of the previous work related to the AM techniques for Ni-base alloys while highlighting current challenges and methods to solving them. The properties of conventionally manufactured Ni-base alloys are also compared with the AM fabricated alloys. The mechanical properties obtained from tension, hardness and fatigue test are included, along with discussions of the effect of post-treatment process. Recommendations for further work are also provided.

Charge and transition densities of samarium isotopes in the interacting Boson model

International Nuclear Information System (INIS)

Moinester, M.A.; Alster, J.; Dieperink, A.E.L.

1982-01-01

The interacting boson approximation (IBA) model has been used to interpret the ground-state charge distributions and lowest 2 + transition charge densities of the even samarium isotopes for A = 144-154. Phenomenological boson transition densities associated with the nucleons comprising the s-and d-bosons of the IBA were determined via a least squares fit analysis of charge and transition densities in the Sm isotopes. The application of these boson trasition densities to higher excited 0 + and 2 + states of Sm, and to 0 + and 2 + transitions in neighboring nuclei, such as Nd and Gd, is described. IBA predictions for the transition densities of the three lowest 2 + levels of 154 Gd are given and compared to theoretical transition densities based on Hartree-Fock calculations. The deduced quadrupole boson transition densities are in fair agreement with densities derived previously from 150 Nd data. It is also shown how certain moments of the best fit boson transition densities can simply and sucessfully describe rms radii, isomer shifts, B(E2) strengths, and transition radii for the Sm isotopes. (orig.)

Corrosion resistance and electrochemical potentiokinetic reactivation testing of some iron-base hardfacing alloys

International Nuclear Information System (INIS)

Cockeram, B.V.

1999-01-01

Hardfacing alloys are weld deposited on a base material to provide a wear resistant surface. Commercially available iron-base hardfacing alloys are being evaluated for replacement of cobalt-base alloys to reduce nuclear plant activation levels. Corrosion testing was used to evaluate the corrosion resistance of several iron-base hardfacing alloys in highly oxygenated environments. The corrosion test results indicate that iron-base hardfacing alloys in the as-deposited condition have acceptable corrosion resistance when the chromium to carbon ratio is greater than 4. Tristelle 5183, with a high niobium (stabilizer) content, did not follow this trend due to precipitation of niobium-rich carbides instead of chromium-rich carbides. This result indicates that iron-base hardfacing alloys containing high stabilizer contents may possess good corrosion resistance with Cr:C < 4. NOREM 02, NOREM 01, and NoCo-M2 hardfacing alloys had acceptable corrosion resistance in the as-deposited and 885 C/4 hour heat treated condition, but rusting from sensitization was observed in the 621 C/6 hour heat treated condition. The feasibility of using an Electrochemical Potentiokinetic Reactivation (EPR) test method, such as used for stainless steel, to detect sensitization in iron-base hardfacing alloys was evaluated. A single loop-EPR method was found to provide a more consistent measurement of sensitization than a double loop-EPR method. The high carbon content that is needed for a wear resistant hardfacing alloy produces a high volume fraction of chromium-rich carbides that are attacked during EPR testing. This results in inherently lower sensitivity for detection of a sensitized iron-base hardfacing alloy than stainless steel using conventional EPR test methods

Tungsten wire-nickel base alloy composite development

Science.gov (United States)

Brentnall, W. D.; Moracz, D. J.

1976-01-01

Further development and evaluation of refractory wire reinforced nickel-base alloy composites is described. Emphasis was placed on evaluating thermal fatigue resistance as a function of matrix alloy composition, fabrication variables and reinforcement level and distribution. Tests for up to 1,000 cycles were performed and the best system identified in this current work was 50v/o W/NiCrAlY. Improved resistance to thermal fatigue damage would be anticipated for specimens fabricated via optimized processing schedules. Other properties investigated included 1,093 C (2,000 F) stress rupture strength, impact resistance and static air oxidation. A composite consisting of 30v/o W-Hf-C alloy fibers in a NiCrAlY alloy matrix was shown to have a 100-hour stress rupture strength at 1,093 C (2,000 F) of 365 MN/square meters (53 ksi) or a specific strength advantage of about 3:1 over typical D.S. eutectics.

Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys

International Nuclear Information System (INIS)

Kalay, Yunus Eren

2008-01-01

Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current dissertation involves an extensive set of experimental, analytical, and computational studies designed to increase the overall understanding of morphological selection, phase competition, and structural hierarchy that occurs under far-from equilibrium conditions. High pressure gas atomization and Cu-block melt-spinning are the two different rapid solidification techniques applied in this study. The research is mainly focused on Al-Si and Al-Sm alloy systems. Silicon and samarium produce different, yet favorable, systems for exploration when alloyed with aluminum under far-from equilibrium conditions. One of the main differences comes from the positions of their respective T 0 curves, which makes Al-Si a good candidate for solubility extension while the plunging T 0 line in Al-Sm promotes glass formation. The rapidly solidified gas-atomized Al-Si powders within a composition range of 15 to 50 wt% Si are examined using scanning and transmission electron microscopy. The non-equilibrium partitioning and morphological selection observed by examining powders at different size classes are described via a microstructure map. The interface velocities and the amount of undercooling present in the powders are estimated from measured eutectic spacings based on Jackson-Hunt (JH) and Trivedi-Magnin-Kurz (TMK) models, which permit a direct comparison of theoretical predictions. For an average particle size of 10 (micro)m with a Peclet number of ∼0.2, JH and TMK deviate from each other. This

Elimination of Iron Based Particles in Al-Si Alloy

Directory of Open Access Journals (Sweden)

Bolibruchová D.

2015-03-01

Full Text Available This paper deals with influence on segregation of iron based phases on the secondary alloy AlSi7Mg0.3 microstructure by chrome. Iron is the most common and harmful impurity in aluminum casting alloys and has long been associated with an increase of casting defects. In generally, iron is associated with the formation of Fe-rich phases. It is impossible to remove iron from melt by standard operations, but it is possible to eliminate its negative influence by addition some other elements that affect the segregation of intermetallics in less harmful type. Realization of experiments and results of analysis show new view on solubility of iron based phases during melt preparation with higher iron content and influence of chrome as iron corrector of iron based phases. By experimental work were used three different amounts of AlCr20 master alloy a three different temperature of chill mold. Our experimental work confirmed that chrome can be used as an iron corrector in Al-Si alloy, due to the change of intermetallic phases and shortening their length.

Mechanisms of improving the cyclic stability of V-Ti-based hydrogen storage electrode alloys

International Nuclear Information System (INIS)

Miao He; Wang Weiguo

2010-01-01

Research highlights: → The corrosion resistance of V-based phase is much lower than that of C14 Laves phase of V-Ti-based alloys. → The addition of Cr which mostly distributes in V-based phase can effectively increase the anti-corrosion ability of V-Ti-based alloys. → The addition of Cr which mostly distributes in V-based phase can effectively increase the anti-corrosion ability of V-Ti-based alloys. - Abstract: In this work, the mechanisms of improving the cyclic stability of V-Ti-based hydrogen storage electrode alloys were investigated systemically. Several key factors for example corrosion resistance, pulverization resistance and oxidation resistance were evaluated individually. The V-based solid solution phase has much lower anti-corrosion ability than C14 Laves phase in KOH solution, and the addition of Cr in V-Ti-based alloys can suppress the dissolution of the main hydrogen absorption elements of the V-based phase in the alkaline solution. During the charge/discharge cycling, the alloy particles crack or break into several pieces, which accelerates their corrosion/oxidation and increases the contact resistance of the alloy electrodes. Proper decreasing the Vickers hardness and enhancing the fracture toughness can increase the pulverization resistance of the alloy particles. The oxidation layer thickness on the alloy particle surface obviously increases during charge/discharge cycling. This deteriorates their electro-catalyst activation to the electrochemical reaction, and leads to a quick degradation. Therefore, enhancing the oxide resistance can obviously improve the cyclic stability of V-Ti-based hydrogen storage electrode alloys.

Enhanced electron-lattice coupling under uniaxial stress in layered double hydroxides intercalated with samarium complexes

International Nuclear Information System (INIS)

Park, Ta-Ryeong

2004-01-01

We have applied uniaxial stress to samarium complexes by intercalating them into the gallery of a layered material and by using a diamond-anvil cell at 28 K. Although uniaxial stress reduces symmetry and removes degeneracy, the overall number of photoluminescence (PL) peaks evidently decreased with the application of uniaxial stress. This contradictory observation is explained by an increased electron-lattice coupling strength under uniaxial stress. This behavior is also confirmed by time-resolved PL data.

Microstructure and mechanical properties of multiphase NiAl-based alloys

Science.gov (United States)

Pank, D. R.; Koss, D. A.; Nathal, M. V.

1990-01-01

The effect of the gamma-prime phase on the deformation behavior and fracture resistance of melt-spun ribbons and consolidated bulk specimens of a series of Nial-based alloys with Co and Hf additions has been examined. The morphology, location, and volume fraction of the gamma-prime phase are significant factors in enhancing the fracture resistance of the normally brittle NiAl-based alloys. In particular, the results indicate that a continuous-grain-boundary film of gamma-prime can impart limited room-temperature ductility regardless of whether B2 or L10 NiAl is present. Guidelines for microstructure control in multiphase NiAl-based alloys are also presented.

Creep-Rupture Behavior of Ni-Based Alloy Tube Bends for A-USC Boilers

Science.gov (United States)

Shingledecker, John

Advanced ultrasupercritical (A-USC) boiler designs will require the use of nickel-based alloys for superheaters and reheaters and thus tube bending will be required. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section II PG-19 limits the amount of cold-strain for boiler tube bends for austenitic materials. In this summary and analysis of research conducted to date, a number of candidate nickel-based A-USC alloys were evaluated. These alloys include alloy 230, alloy 617, and Inconel 740/740H. Uniaxial creep and novel structural tests and corresponding post-test analysis, which included physical measurements, simplified analytical analysis, and detailed microscopy, showed that different damage mechanisms may operate based on test conditions, alloy, and cold-strain levels. Overall, creep strength and ductility were reduced in all the alloys, but the degree of degradation varied substantially. The results support the current cold-strain limits now incorporated in ASME for these alloys for long-term A-USC boiler service.

Excessively High Vapor Pressure of Al-based Amorphous Alloys

Directory of Open Access Journals (Sweden)

Jae Im Jeong

2015-10-01

Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

Phase Composition of Samarium Niobate and Tantalate Thin Films Prepared by Sol-Gel Method

Science.gov (United States)

Bruncková, H.; Medvecký, Ľ.; Múdra, E.; Kovalčiková, A.; Ďurišin, J.; Šebek, M.; Girman, V.

2017-12-01

Samarium niobate SmNbO4 (SNO) and tantalate SmTaO4 (STO) thin films ( 100 nm) were prepared by sol-gel/spin-coating process on alumina substrates with PZT interlayer and annealing at 1000°C. The precursors of films were synthesized using Nb or Ta tartrate complexes. The improvement of the crystallinity of monoclinic M'-SmTaO4 phase via heating was observed through the coexistence of small amounts of tetragonal T-SmTa7O19 phase in STO precursor at 1000°C. The XRD results of SNO and STO films confirmed monoclinic M-SmNbO4 and M'-SmTaO4 phases, respectively, with traces of orthorhombic O-SmNbO4 (in SNO). In STO film, the single monoclinic M'-SmTaO4 phase was revealed. The surface morphology and topography of thin films were investigated by SEM and AFM analysis. STO film was smoother with roughness 3.2 nm in comparison with SNO (6.3 nm). In the microstructure of SNO film, small spherical ( 50 nm) and larger cuboidal particles ( 100 nm) of the SmNbO4 phase were observed. In STO, compact clusters composed of fine spherical SmTaO4 particles ( 20-50 nm) were found. Effect of samarium can contribute to the formation different polymorphs of these films for the application to environmental electrolytic thin film devices.

Improvement of the performance of Mg-based alloy electrodes at ambient temperatures

International Nuclear Information System (INIS)

Liu, H.K.; Chen, J.; Sun, L.; Bradhurst, D.H.; Dou, S.X.

1998-01-01

Full text: Rechargeable batteries are finding increased application in modern communications, computers, and electric vehicles. The Nickel-Metal Hydride (Ni-MH) battery has the best comprehensive properties. It is known that the important step to increase the energy density of Ni-MH battery is to improve the negative (metal hydride) electrode properties. Of all the hydrogen storage alloys studied previously, (the best know alloys are LaNi 5 , Mg 2 Ni, Ti 2 Ni , TiNi and Zr 2 Ni), the intermetallic compound Mg 2 Ni has the highest theoretical hydrogen storage capacity. The Mg 2 Ni-based hydrogen storage alloy is a promising material for increasing the negative electrode capacity of Ni-MH batteries because this alloy is superior to the LaNi 5 -system or the Zr-based alloys in materials cost and hydrogen absorption capacity. A serious disadvantage, however, is that the reactions of most magnesium based alloys with hydrogen require relatively high temperature (>300 deg C) and pressure (up to 10 atm) due to the slowness of the hydriding/dehydriding reactions. In this paper it is shown that with a combination of modifications to the alloy composition and methods of electrode preparation, magnesium-based alloys can be made into electrodes which will not only be useful at ambient temperatures but will have a useful cycle life and extremely high capacity

Evaluation of samarium-153 and holmium-166-EDTMP in the normal baboon model

Energy Technology Data Exchange (ETDEWEB)

Louw, W.K.A.; Dormehl, I.C.; Rensburg, A.J. van; Hugo, N.; Alberts, A.S.; Forsyth, O.E.; Beverley, G.; Sweetlove, M.A.; Marais, J.; Loetter, M.G.; Aswegen, A. van

1996-11-01

Bone-seeking radiopharmaceuticals such as ethylenediaminetetramethylene phosphonate (EDTMP) complexes of samarium-153 and holmium-166 are receiving considerable attention for therapeutic treatment of bone metastases. In this study, using the baboon experimental model, multicompartmental analysis revealed that with regard to pharmacokinetics, biodistribution, and skeletal localisation, {sup 166}Ho-EDTMP was significantly inferior to {sup 153}Sm-EDTMP and {sup 99m}Tc-MDP. A more suitable {sup 166}Ho-bone-seeking agent should thus be sought for closer similarity to {sup 153}Sm-EDTMP to exploit fully the therapeutic potential of its shorter half-life and more energetic beta radiation.

Performance analysis of samarium cobalt P.M. synchronous motor fed from PWM inverters

International Nuclear Information System (INIS)

Rahman, M.A.; Choudhury, M.A.

1985-01-01

This paper presents an analysis and performance of samarium cobalt permanent magnet (P.M.) synchronous motors fed from two types of voltage source pulse width modulated (PWM) inverters. The analysis and test results on the steady state performance of a P.M. motor fed from PWM inverters are presented. PWM inverters are used in variable voltage variable frequency applications to avoid a double conversion process of ordinary inverters. In drives, they are used for voltage and speed regulation of motors. Use of modulation technique in inverters also allow to eliminate or minimize selected harmonics from the inverter output voltage

Neutronographic Texture Analysis of Zirconium Based Alloys

International Nuclear Information System (INIS)

Kruz'elová, M; Vratislav, S; Kalvoda, L; Dlouhá, M

2012-01-01

Neutron diffraction is a very powerful tool in texture analysis of zirconium based alloys used in nuclear technique. Textures of five samples (two rolled sheets and three tubes) were investigated by using basal pole figures, inversion pole figures, and ODF distribution function. The texture measurement was performed at diffractometer KSN2 on the Laboratory of Neutron Diffraction, Department of Solid State Engineering, Faculty of Nuclear Sciences and Physical Engineering, CTU in Prague. Procedures for studying textures with thermal neutrons and procedures for obtaining texture parameters (direct and inverse pole figures, three dimensional orientation distribution function) are also described. Observed data were processed by software packages HEXAL and GSAS. Our results can be summarized as follows: i) All samples of zirconium alloys show the distribution of middle area into two maxima in basal pole figures. This is caused by alloying elements. A characteristic split of the basal pole maxima tilted from the normal direction toward the transverse direction can be observed for all samples, ii) Sheet samples prefer orientation of planes (100) and (110) perpendicular to rolling direction and orientation of planes (002) perpendicular to normal direction, iii) Basal planes of tubes are oriented parallel to tube axis, meanwhile (100) planes are oriented perpendicular to tube axis. Level of resulting texture and maxima position is different for tubes and for sheets. The obtained results are characteristic for zirconium based alloys.

Nickel-base alloy forgings for advanced high temperature power plants

Energy Technology Data Exchange (ETDEWEB)

Donth, B.; Diwo, A.; Blaes, N.; Bokelmann, D. [Saarschmiede GmbH Freiformschmiede, Voelklingen (Germany)

2008-07-01

The strong efforts to reduce the CO{sub 2} emissions lead to the demand for improved thermal efficiency of coal fired power plants. An increased thermal efficiency can be realised by higher steam temperatures and pressures in the boiler and the turbine. The European development aims for steam temperatures of 700 C which requires the development and use of new materials and also associated process technology for large components. Temperatures of 700 C and above are too high for the application of ferritic steels and therefore only Nickel-Base Alloys can fulfill the required material properties. In particular the Nickel-Base Alloy A617 is the most candidate alloy on which was focused the investigation and development in several German and European programs during the last 10 years. The goal is to verify and improve the attainable material properties and ultrasonic detectability of large Alloy 617 forgings for turbine rotors and boiler parts. For many years Saarschmiede has been manufacturing nickel and cobalt alloys and is participating the research programs by developing the manufacturing routes for large turbine rotor forgings up to a maximum diameter of 1000 mm as well as for forged tubes and valve parts for the boiler side. The experiences in manufacturing and testing of very large forgings made from nickel base alloys for 700 C steam power plants are reported. (orig.)

Corrosion behaviour of powder metallurgical and cast Al-Zn-Mg base alloys

International Nuclear Information System (INIS)

Sameljuk, A.V.; Neikov, O.D.; Krajnikov, A.V.; Milman, Yu.V.; Thompson, G.E.

2004-01-01

The behaviour of Al-Zn-Mg base alloys produced by powder metallurgy and casting has been studied using potentiodynamic polarisation in 0.3% and 3% NaCl solutions. The influence of alloy production route on microstructure has been examined by scanning electron microscopy, Auger electron spectroscopy and secondary ion mass spectrometry. An improvement in performance of powder metallurgy (PM) materials, compared with the cast alloy, was evident in solutions of low chloride concentration; less striking differences were revealed in high chloride concentration. Both powder metallurgy and cast alloys show two main types of precipitates, which were identified as Zn-Mg and Zr-Sc base intermetallic phases. The microstructure of the PM alloys is refined compared with the cast material, which assists understanding of the corrosion performance. The corrosion process commences with dissolution of the Zn-Mg base phases, with the relatively coarse phases present in the cast alloy showing ready development of corrosion

Three dimensional atom probe study of Ni-base alloy/low alloy steel dissimilar metal weld interfaces

International Nuclear Information System (INIS)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun

2012-01-01

Three dimensional atom probe tomography (3D APT) is applied to characterize the dissimilar metal joint which was welded between the Ni-based alloy, Alloy 690 and the low alloy steel, A533 Gr. B, with Alloy 152 filler metal. While there is some difficulty in preparing the specimen for the analysis, the 3D APT has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multicomponent metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. In this study, the procedure for 3D APT specimen preparation was established, and those for dissimilar metal weld interface were prepared near the fusion boundary by a focused ion beam. The result of the analysis in this study showed the precipitation of chromium carbides near the fusion boundary between A533 Gr. B and Alloy 152.

Three dimensional atom probe study of Ni-base alloy/low alloy steel dissimilar metal weld interfaces

Energy Technology Data Exchange (ETDEWEB)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2012-08-15

Three dimensional atom probe tomography (3D APT) is applied to characterize the dissimilar metal joint which was welded between the Ni-based alloy, Alloy 690 and the low alloy steel, A533 Gr. B, with Alloy 152 filler metal. While there is some difficulty in preparing the specimen for the analysis, the 3D APT has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multicomponent metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. In this study, the procedure for 3D APT specimen preparation was established, and those for dissimilar metal weld interface were prepared near the fusion boundary by a focused ion beam. The result of the analysis in this study showed the precipitation of chromium carbides near the fusion boundary between A533 Gr. B and Alloy 152.

Highly corrosion resistant zirconium based alloy for reactor structural material

International Nuclear Information System (INIS)

Ito, Yoichi.

1996-01-01

The alloy of the present invention is a zirconium based alloy comprising tin (Sn), chromium (Cr), nickel (Ni) and iron (Fe) in zirconium (Zr). The amount of silicon (Si) as an impurity is not more than 60ppm. It is preferred that Sn is from 0.9 to 1.5wt%, that of Cr is from 0.05 to 0.15wt%, and (Fe + Ni) is from 0.17 to 0.5wt%. If not less than 0.12wt% of Fe is added, resistance against nodular corrosion is improved. The upper limit of Fe is preferably 0.40wt% from a view point of uniform suppression for the corrosion. The nodular corrosion can be suppressed by reducing the amount of Si-rich deposition product in the zirconium based alloy. Accordingly, a highly corrosion resistant zirconium based alloy improved for the corrosion resistance of zircaloy-2 and usable for a fuel cladding tube of a BWR type reactor can be obtained. (I.N.)

Retention capacity of samarium (III) in zircon for it possible use in retaining walls for confinement of nuclear residues

International Nuclear Information System (INIS)

Garcia G, N.

2006-01-01

Mexico, as country that produces part of its electric power by nuclear means, should put special emphasis in the development of technologies guided to the sure and long term confinement of the high level nuclear residuals. This work studies the capacity that has the natural zircon to retain to the samarium (III) in solution, by what due, firstly, to characterize the zircon for technical instrumental to determine the purity and characteristic of the mineral in study. The instrumental techniques that were used to carry out the physicochemical characterization were the neutron activation analysis (NAA), the infrared spectroscopy (IS), the thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), semiquantitative analysis, dispersive energy spectroscopy (EDS), X-ray diffraction (XRD) and luminescence technique. The characterization of the surface properties carries out by means of the determination of the surface area using the BET multipoint technique, acidity constants, hydration time, the determination of the point of null charge (pH PCN ) and density of surface sites (D s ). The luminescence techniques were useful to determine the optimal point hydration of the zircon and for the quantification of the samarium, for that here intends the development of both analysis techniques. With the adjustment of the titration curves in the FITEQL 4 package the constants of surface acidity in the solid/liquid interface were determined. To the finish of this study it was corroborated that the zircon is a mineral that presents appropriate characteristics to be proposed as a contention barrier for the deep geologic confinement. With regard to the study of adsorption that one carries out the samarium retention it is superior to 90% under the described conditions. This investigation could also be applicable in the confinement of dangerous industrial residuals. (Author)

Precipitation hardened nickel-base alloys for sour gas environments

International Nuclear Information System (INIS)

Igarashi, M.; Mukai, S.; Kudo, T.; Okada, Y.; Ikeda, A.

1987-01-01

SCC (Stress Corrosion Cracking) in sour gas environments of γ'(gamma prime: Ni/sub 3/(Ti and/or Al)) and γ''(gamma double prime: Ni/sub 3/Nb) precipitation hardened nickel-base alloys has been studied using the SSRT (Slow Strain Rate Tensile) test, anodic polarization measurement and transmission electron microscopy (TEM). The γ'-type alloy containing Ti was more susceptible to SCC in the SSRT tests up to 350 0 F(450 K) than the γ''-type alloy containing Nb. The susceptibility to SCC was related to their deformation structures in terms of stress localization and sensitivity to pitting corrosion in H/sub 2/S solutions. TEM observation showed the γ'-type alloy deformed by the superlattice dislocations in coplanar structures. This mode of deformation induced the stress localization to some boundaries such as grain boundary and as a result the susceptibility to SCC of the γ'-type alloy was increased. On the other hand, the γ''-type alloy deformed by the massive dislocation not in coplanar structures so that it was less susceptible to SCC in terms of the stress localization. The anodic polarization measurement suggested the γ'-type alloy was more susceptible to pitting corrosion compared with the γ''-type alloy

Optical properties and electronic transitions of zinc oxide, ferric oxide, cerium oxide, and samarium oxide in the ultraviolet and extreme ultraviolet

DEFF Research Database (Denmark)

Pauly, N; Yubero, F; Espinós, J P

2017-01-01

Optical properties and electronic transitions of four oxides, namely zinc oxide, ferric oxide, cerium oxide, and samarium oxide, are determined in the ultraviolet and extreme ultraviolet by reflection electron energy loss spectroscopy using primary electron energies in the range 0.3-2.0 ke...

Corrosion behavior of Nb-based and Mo-based super heat-resisting alloys in liquid Li

International Nuclear Information System (INIS)

Saito, J.; Kano, S.; Morinaga, M.

1998-07-01

Research on structural materials which will be utilized even in the severe environment of high-temperature liquid alkali metals has been promoted in order to develop the frontiers of materials techniques. The super-heat resisting alloys which are based on refractory metals, Nb and Mo, are aimed as promising materials used in such an environment. The corrosion resistance in liquid Li and the mechanical properties such as creep and tensile strengths at high temperatures are important for these structural materials. On the basis of many experiments and analyses of these properties at 1473 K, the material design of Nb-based and Mo-based alloys has been carried out successfully. In this report, all the previous experimental results of corrosion tests in liquid Li were summarized systematically for Nb-based and Mo-based alloys. The corrosion mechanism was proposed on the basis of a series of analyses, in particular, focussing on the deposition mechanism of corrosion products on the surface and also on the initiation and growth mechanism of cracks on the corroded surface of Nb-based alloys. The principal results are as follows. (1) For the deposition mechanism, a reaction took place first between dissolved metallic elements and nitrogen which existed as an impurity in liquid Li and then corrosion products (nitrides) precipitated on the metal surface. Subsequently, another reaction took place between dissolved metallic elements in liquid Li, and corrosion products (intermetallic compounds) precipitated on the metal surface. The composition of deposited corrosion products could be predicted on the basis of the deposition mechanism. (2) For the crack initiation mechanism, the chemical potential diagrams were utilized in order to understand the formation of Li-M-O ternary oxides which caused cracks to be formed on the corroded surface. Consequently, it was evident that not only the concentration of the dissolved oxygen in the alloy but also the concentration of Li which

Effect of ternary alloying elements on microstructure and mechanical property of Nb-Si based refractory intermetallic alloy

International Nuclear Information System (INIS)

Kim, W.Y.; Kim, H.S.; Kim, S.K.; Ra, T.Y.; Kim, M.S.

2005-01-01

Microstructure and mechanical property at room temperature and at 1773 K of Nb-Si based refractory intermetallic alloys were investigated in terms of compression and fracture toughness test. Mo and V were chosen as ternary alloying elements because of their high melting points, atomic sizes smaller than Nb. Both ternary alloying elements were found to have a significant role in modifying the microstructure from dispersed structure to eutectic-like structure in Nb solid solution/Nb 5 Si 3 intermetallic composites. The 0.2% offset yield strength at room temperature increased with increasing content of ternary elements in Nb solid solution and volume fraction of Nb 5 Si 3 . At 1773 K, Mo addition has a positive role in increasing the yield strength. On the other hand, V addition has a role in decreasing the yield strength. The fracture toughness of ternary alloys was superior to binary alloys. Details will be discussed in correlation with ternary alloying, volume fraction of constituent phase, and the microstructure. (orig.)

Transmission electron microscopy characterization of laser-clad iron-based alloy on Al-Si alloy

International Nuclear Information System (INIS)

Mei, Z.; Wang, W.Y.; Wang, A.H.

2006-01-01

Microstructure characterization is important for controlling the quality of laser cladding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the iron-based alloy laser-clad on Al-Si alloy and an unambiguous identification of phases in the coating was accomplished. It was found that there is austenite, Cr 7 C 3 and Cr 23 C 6 in the clad region; α-Al, NiAl 3 , Fe 2 Al 5 and FeAl 2 in the interface region; and α-Al and silicon in the heat-affected region. A brief discussion was given for their existence based on both kinetic and thermodynamic principles

Magnetic behavior study of samarium nitride using density functional theory

Science.gov (United States)

Som, Narayan N.; Mankad, Venu H.; Dabhi, Shweta D.; Patel, Anjali; Jha, Prafulla K.

2018-02-01

In this work, the state-of-art density functional theory is employed to study the structural, electronic and magnetic properties of samarium nitride (SmN). We have performed calculation for both ferromagnetic and antiferromagnetic states in rock-salt phase. The calculated results of optimized lattice parameter and magnetic moment agree well with the available experimental and theoretical values. From energy band diagram and electronic density of states, we observe a half-metallic behaviour in FM phase of rock salt SmN in while metallicity in AFM I and AFM III phases. We present and discuss our current understanding of the possible half-metallicity together with the magnetic ordering in SmN. The calculated phonon dispersion curves shows dynamical stability of the considered structures. The phonon density of states and Eliashberg functional have also been analysed to understand the superconductivity in SmN.

Myelotoxicity of Samarium Sm153 lexidronam in patients with painful bony metastases

International Nuclear Information System (INIS)

Ben Ghachem, T.; Mhiri, A.; Slim, I.; Bahloul, A.; Yeddes, I.; Elbez, I.; Meddeb, I.; Ben Slimene, M.F.

2015-01-01

Full text of publication follows. Introduction: the management of bone pain includes analgesia, radiation, hormones, radiofrequency (RF) ablation, chemotherapy, and surgery. Bone pain palliation therapy with radiopharmaceuticals is a cost-effective systemic therapy to relieve pain from skeletal metastases with a consequent decrease in morbidity and an improvement in quality of life. The aim of our study is to evaluate the effect of myelotoxicity of samarium lexidronam (Sm 153 ) in patients with painful bony metastasis. Methods: we reviewed 116 patients aged from 14 to 87 years old, 91 males (78%) and 25 females (22%), having received 1 to 4 treatments of Sm 153 (37 MBq/kg) for painful bony metastases from different primitive tumors: 67 cases of prostate cancer (57.7%), 22 cases of breast cancer (18.9%), 10 cases of pulmonary cancer (8.6%) and others in 14.6% of cases. Clinical follow-up was available for 159 treatments, consisting on blood count each week over at least two months, in order to evaluate myelotoxicity according to WHO classification. Results: no patients had grade 4 toxicity after its cures. A grade 2-3 myelotoxicity was observed after 52 treatments (34%) during the second week and after 50 treatments (32.6%) during the fourth week with a satisfactory reversibility. At 10 weeks of treatment, myelotoxicity was reclassified from 0 to 2 for 139 cures (90,8%). Moreover, we found that prior treatment with radiotherapy or chemotherapy did not affect the rates of myelotoxicity. Conclusion: multiple treatments with samarium Sm 153 lexidronam had no significant effect on myelotoxicity. Patients with bone predominant metastatic disease may survive for extended periods of time and may safely be treated with multiple modalities of therapy. (authors)

Microstructure evolution and texture development in thermomechanically processed Mg-Li-Al based alloys

Energy Technology Data Exchange (ETDEWEB)

Kumar, Vinod [Department of Materials Science and Engineering, IIT Kanpur (India); Govind [Vikram Sarabhai Space Center, Trivandrum (India); Shekhar, Rajiv; Balasubramaniam, R. [Department of Materials Science and Engineering, IIT Kanpur (India); Balani, Kantesh, E-mail: kbalani@iitk.ac.in [Department of Materials Science and Engineering, IIT Kanpur (India)

2012-06-15

Highlights: Black-Right-Pointing-Pointer Thermomechanical processing of novel LAT 971 and LATZ 9531 Mg-Al-Li based alloys. Black-Right-Pointing-Pointer Microstructural deviation from the equilibrium phase diagram. Black-Right-Pointing-Pointer Disparity in texture of these alloys after hot-rolling (recrystallization and grain growth). Black-Right-Pointing-Pointer Role of alloying and phase distribution in affecting the texture/interplaner spacing. - Abstract: In the present study, the influence of alloying and thermomechanical processing on the microstructure and texture evolution on the two Mg-Li-Al based alloys, namely Mg-9 wt% Li-7 wt% Al-1 wt% Sn (LAT971) and Mg-9 wt% Li-5 wt% Al-3 wt% Sn-1 wt% Zn (LATZ9531) has been elicited. Novel Mg-Li-Al based alloys were cast (induction melting under protective atmosphere) followed by hot rolling at {approx}573 K with a cumulative reduction of five. A contrary dual phase dendritic microstructure rich in {alpha}-Mg, instead of {beta}-Li phase predicted by equilibrium phase diagram of Mg-Li binary alloy was observed. Preferential presence of Mg-Li-Sn primary precipitates (size 4-10 {mu}m) within {alpha}-Mg phase and Mg-Li-Al secondary precipitates (<3 {mu}m) interspersed in {beta}-Li indicated their degree of dissolution during hot-rolling and homogenization in the dual phase matrix. Presence of Al, Sn and Zn alloying elements in the Mg-Li based alloy has resulted an unusual dual-phase microstructure, change in the lattice parameter, and intriguing texture evolution after hot-rolling of cast LAT 971 and LATZ9531 alloy. Strong texture was absent in the as-cast samples whereas texture development after hot-rolling revealed an increased activity of the non-basal (101{sup Macron }0) slip planes. The quantification of the grain average misorientation (less than 2 Degree-Sign ) using electron backscattered diffraction confirmed the presence of strain free grains in majority of the grains (fraction >0.75) after hot-rolling of Mg

Nitriding behavior of Ni and Ni-based binary alloys

Energy Technology Data Exchange (ETDEWEB)

Fonovic, Matej

2015-01-15

Gaseous nitriding is a prominent thermochemical surface treatment process which can improve various properties of metallic materials such as mechanical, tribological and/or corrosion properties. This process is predominantly performed by applying NH{sub 3}+H{sub 2} containing gas atmospheres serving as the nitrogen donating medium at temperatures between 673 K and 873 K (400 C and 600 C). NH{sub 3} decomposes at the surface of the metallic specimen and nitrogen diffuses into the surface adjacent region of the specimen whereas hydrogen remains in the gas atmosphere. One of the most important parameters characterizing a gaseous nitriding process is the so-called nitriding potential (r{sub N}) which determines the chemical potential of nitrogen provided by the gas phase. The nitriding potential is defined as r{sub N} = p{sub NH{sub 3}}/p{sub H{sub 2}{sup 3/2}} where p{sub NH{sub 3}} and p{sub H{sub 2}} are the partial pressures of the NH{sub 3} and H{sub 2} in the nitriding atmosphere. In contrast with nitriding of α-Fe where the nitriding potential is usually in the range between 0.01 and 1 atm{sup -1/2}, nitriding of Ni and Ni-based alloys requires employing nitriding potentials higher than 100 atm{sup -1/2} and even up to ∞ (nitriding in pure NH{sub 3} atmosphere). This behavior is compatible with decreased thermodynamic stability of the 3d-metal nitrides with increasing atomic number. Depending on the nitriding conditions (temperature, nitriding potential and treatment time), different phases are formed at the surface of the Ni-based alloys. By applying very high nitriding potential, formation of hexagonal Ni{sub 3}N at the surface of the specimen (known as external nitriding) leads to the development of a compound layer, which may improve tribological properties. Underneath the Ni{sub 3}N compound layer, two possibilities exist: (i) alloying element precipitation within the nitrided zone (known as internal nitriding) and/or (ii) development of metastable and

An overview of advanced high-strength nickel-base alloys for LWR applications

International Nuclear Information System (INIS)

Prybylowski, J.; Ballinger, R.G.

1989-01-01

This paper reviews our current understanding of the behavior of high strength nickel base alloys used in light water reactor (LWR) applications. Emphasis is placed on understanding the fundamental mechanisms controlling crack propagation in these environments. To provide a foundation for this survey, general mechanisms of stress corrosion cracking and hydrogen embrittlement are first reviewed. The behavior of high strength nickel base alloys in LWR environments, as well as in other relevant environments is then reviewed. Suggested mechanisms of crack propagation are discussed. Alternate alloys and microstructural modifications that may result in improved behavior are presented. It is now clear that, at temperatures near 100C, alloy X-750, the predominant high strength nickel base alloy used today in LWR applications, is susceptible to hydrogen embrittlement. A review of published data from hydrogen embrittlement studies of nickel base superalloys during electrolytic charging and in hydrogen sulfide/brine solutions suggests that other nickel base superalloys are available possessing resistance to hydrogen embrittlement superior to that of alloy X-750. Available results of tests in gaseous hydrogen suggest that reduced grain boundary precipitation and a fine distribution of intragranular precipitates that act as irreversible hydrogen traps is the optimum microstructure for hydrogen embrittlement resistance. 42 refs., 2 figs., 5 tabs

Preparation and biological behaviour of samarium-153-hydroxyapatite particles for radiation synovectomy

International Nuclear Information System (INIS)

Agrueelles, M.G.; Luppi Berlanga, I.S.; Torres, E.A.; Rutty Sola, G.A.; Rimoldi, G.

1998-01-01

The preparation and labelling procedures of 153 Sm-hydroxyapatite ( 153 Sm-HA) are described in this paper. Hydroxyapatite (HA) was prepared and studied as a radiosynovectomy agent. HA particles were prepared from the reaction of calcium nitrate and ammonia phosphate at high pH Samarium-153 labelling was done in two steps with citric acid. A serie of experimental conditions, such as specific activity, citric acid mass, radioactive solution volume, in-vitro stability, have been carried out. Radiolabelling efficiency was greater than 95%. In vitro studies showed high stability (≥99%). Animal studies showed a good retention in the synovium, with a very low extra-articular leakage over 6 days after administration. (author)

A new high-strength iron base austenitic alloy with good toughness and corrosion resistance (GE-EPRI alloy-TTL)

International Nuclear Information System (INIS)

Ganesh, S.

1989-01-01

A new high strength, iron based, austenitic alloy has been successfully developed by GE-EPRI to satisfy the strength and corrosion resistance requirements of large retaining rings for high capacity generators (>840Mw). This new alloy is a modified version of the EPRI alloy-T developed by the University of California, Berkeley, in an earlier EPRI program. It is age hardenable and has the nominal composition (weight %): 34.5 Ni, 5Cr, 3Ti, 1Nb, 1Ta, 1Mo, .5Al, .3V, .01B. This composition was selected based on detailed metallurgical and processing studies on modified versions of alloy-T. These studies helped establish the optimum processing conditions for the new alloy and enabled the successful scale-up production of three large (50-52 inch dia) test rings from a 5,000 lb VIM-VAR billet. The rings were metallurgically sound and exhibited yield strength capabilities in the range 145 to 220 ksi depending on the extent of hot/cold work induced. The test rings met or exceeded all the property goals. The above alloy can provide a good combination of strength, toughness and corrosion resistance and, through an suitable modification of chemistry or processing conditions, could be a viable candidate for high strength LWR internal applications. 3 figs

Corrosion and wear protective composition modulated alloy coatings based on ternary Ni-P-X alloys

DEFF Research Database (Denmark)

Leisner, P.; Benzon, M. E.; Christoffersen, Lasse

1996-01-01

Scattered reporting in the litterature describes a number of ternary Ni-P-X alloyes (where X can be Co, Cr, Cu, Mo, Pd, Re or W) with promising corrosin and wear protective performance. Based on a systematic study of Ni-P-X alloys it is the intention to produce coatings with improved corrosion...... and wear performance compared with conventional coatings like electroless nickel, hard chromioum and anodised aluminium....

On the superconductivity of vanadium based alloys

International Nuclear Information System (INIS)

Brouers, F.; Rest, J. Van der

1984-01-01

The electron density of states of solid solutions of vanadium based transition metal alloys V 90 X 10 is computed with the aim of calculating the superconducting transition temperature using the McMillan formula. As observed experimentally for X on the left hand side of V in the periodic table, one obtains an increase of Tc while for X on the right hand side of V the critical temperature decreases. The detailed comparison with experiments indicate that when the bandwidths of the two constituents are different, one cannot neglect the variation of the electron-phonon interactions. Another important conclusion is that for alloys which are in the split-band limit like VAu, VPd and VPt, the agreement with experimental data can be obtained only by assuming that these alloys have a short-range order favouring clusters of pure vanadium. (Author) [pt

Computational studies of physical properties of Nb-Si based alloys

Energy Technology Data Exchange (ETDEWEB)

Ouyang, Lizhi [Middle Tennessee State Univ., Murfreesboro, TN (United States)

2015-04-16

The overall goal is to provide physical properties data supplementing experiments for thermodynamic modeling and other simulations such as phase filed simulation for microstructure and continuum simulations for mechanical properties. These predictive computational modeling and simulations may yield insights that can be used to guide materials design, processing, and manufacture. Ultimately, they may lead to usable Nb-Si based alloy which could play an important role in current plight towards greener energy. The main objectives of the proposed projects are: (1) developing a first principles method based supercell approach for calculating thermodynamic and mechanic properties of ordered crystals and disordered lattices including solid solution; (2) application of the supercell approach to Nb-Si base alloy to compute physical properties data that can be used for thermodynamic modeling and other simulations to guide the optimal design of Nb-Si based alloy.

Zirconium-based alloys, nuclear fuel rods and nuclear reactors including such alloys, and related methods

Science.gov (United States)

Mariani, Robert Dominick

2014-09-09

Zirconium-based metal alloy compositions comprise zirconium, a first additive in which the permeability of hydrogen decreases with increasing temperatures at least over a temperature range extending from 350.degree. C. to 750.degree. C., and a second additive having a solubility in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. At least one of a solubility of the first additive in the second additive over the temperature range extending from 350.degree. C. to 750.degree. C. and a solubility of the second additive in the first additive over the temperature range extending from 350.degree. C. to 750.degree. C. is higher than the solubility of the second additive in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. Nuclear fuel rods include a cladding material comprising such metal alloy compositions, and nuclear reactors include such fuel rods. Methods are used to fabricate such zirconium-based metal alloy compositions.

Glass formation and crystallization in Zr based alloys

International Nuclear Information System (INIS)

Dey, G. K.

2011-01-01

Metallic glasses have come in to prominence in recent times because their nanocrystalline atomic arrangement imparts many useful and unusual properties to these metallic solids. Though these have been produced for the last four decades, the necessity of rapid solidification at cooling rates of 10 5 K/sec or higher for their production, have restricted their geometry to thin ribbons and prevented their application to many areas despite their excellent properties. It has been shown in recent investigations that, many Zr base multicomponent alloys can be obtained in glassy state by cooling at much lower rate typically 10 2 to 10 3 K/sec. This has enabled production of these alloys in the glassy stat in bulk. By now, bulk metallic glasses have been produced in Mg, Ln, Zr, Fe, Pd-Cu, Pd-Fe, Ti and Ni- based alloys. Production of these glasses in bulk has opened avenue for their application in many areas where their excellent mechanical properties an corrosion resistance can be exploited. The transformation of the amorphous phase in these alloys to one or more crystalline phases, is an interesting phase transformation and can lead to formation of crystals in a variety of morphologies and a wide range of crystal sizes, including nanometer size crystals or nanocrystals. The bulk amorphous alloys exhibit higher fracture stress, combined with higher hardness and lower young's modulus than those of any crystalline alloy. The Zr- and Ti-based bulk amorphous alloy exhibit high bending and flexural strength values which are typically 2.0 to 2.5 time higher than those for crystalline counterparts. The composites of bulk metallic glass containing crystalline phases have been found to have special properties. This has been demonstrated in the case of composites of bulk metallic glass and tungsten wires wit the glass forming the matrix. Such a composite has a very high impact strength and is especially suitable for application as an armour penetrator in various types of shells used

Influence of alkali metal hydroxides on corrosion of Zr-base alloys

International Nuclear Information System (INIS)

Jeong, Yong Hwan

1996-01-01

The influence of group-1 alkali hydroxides on different Zr-based alloys have been carried out in static autoclaves at 350 deg C in pressurized water, conditioned in low(0.32 mmol), medium(4.3 mmol) and high(31.5 mmol) equimolar concentration of Li-, Na-, K-, Rb- and Cs-hydroxide. Two types of alloys have been investigated: Zr-Sn-(TRM, Transition metal) and Zr-Sn-Nb-(TRM, Transition metal). From the experiments the cation could be identified as the responsible species for corrosion of Zr alloy in alkalized water. The radius of the cation governs the accelerated corrosion in the pre-transition region of Zr alloy. Incorporation of alkali cation into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significant lower effect for the other bases. Nb containing alloys showed lower corrosion resistance than Zr-Sn-TRM alloys in all alkali solutions. Both types of alloys were corroded significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behavior in the different alkali environments and taking into account the tendency to accelerate the corrosion of Zr alloys, CsOH and KOH are possible alternate alkali for PWR (Pressurized Water Reactor) application. (author)

Cu-based shape memory alloys with enhanced thermal stability and mechanical properties

International Nuclear Information System (INIS)

Chung, C.Y.; Lam, C.W.H.

1999-01-01

Cu-based shape memory alloys were developed in the 1960s. They show excellent thermoelastic martensitic transformation. However the problems in mechanical properties and thermal instability have inhibited them from becoming promising engineering alloys. A new Cu-Zn-Al-Mn-Zr Cu-based shape memory alloy has been developed. With the addition of Mn and Zr, the martensitic transformation behaviour and the grain size ca be better controlled. The new alloys demonstrates good mechanical properties with ultimate tensile strenght and ductility, being 460 MPa and 9%, respectively. Experimental results revealed that the alloy has better thermal stability, i.e. martensite stabilisation is less serious. In ordinary Cu-Zn-Al alloys, martensite stabilisation usually occurs at room temperature. The new alloy shows better thermal stability even at elevated temperature (∝150 C, >A f =80 C). A limited small amount of martensite stabilisation was observed upon ageing of the direct quenched samples as well as the step quenched samples. This implies that the thermal stability of the new alloy is less dependent on the quenching procedure. Furthermore, such minor martensite stabilisation can be removed by subsequent suitable parent phase ageing. The new alloy is ideal for engineering applications because of its better thermal stability and better mechanical properties. (orig.)

Elastic characteristics and microplastic deformation of amorphous alloys on iron base

International Nuclear Information System (INIS)

Pol'dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret'yakov, B.N.

1983-01-01

Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit σsub(0.01) and yield limit σsub(0.2)) of three amorphous alloys on iron base Fe 80 B 20 , Fe 70 Cr 10 B 20 and Fe 70 Cr 5 Ni 5 B 20 are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials

Pharmacokinetics of labelled compounds with technetium-99m and samarium-153

International Nuclear Information System (INIS)

Borda O, L.B.; Torres L, M.N.

1997-01-01

The purpose of this investigation was to establish the different pharmacokinetics parameters of the main radiopharmaceuticals labeled with technetium-99m and samarium-153. These parameters could be subsequently used as reference to compare other products with the same use. Mathematical models and a computerized pharmacokinetic program were used to this purpose. A biodistribution study in quadruplicate and/or quintuplicate was conducted for each radiopharmaceutical, data was was obtained in injection dose percentages. The biodistribution study involved the injection of a predetermined dose of the radiopharmaceutical into animals (rats or mice), which were subsequently put away at different time intervals, removing the relevant organs. Activity in each organ was read by means of a well-type NaI scintillation counter, data obtained in activity counts was transformed into injection dose percentages. Based on these percentages, the mathematical model was constructed and the pharmacokinetic parameters were obtained using the computerized program Expo 2 v. 1, which is written in C language and works in windows. Analyzing the results obtained, we can conclude that the use of the Expo 2 v. 1 program for a bi compartmental analysis allowed us to obtain reliable pharmacokinetic parameters which describe what happens in the organism when the radiopharmaceutical passes from the central compartment to the peripheral one and vice versa

Optical and physical properties of samarium doped lithium diborate glasses

Science.gov (United States)

Hanumantharaju, N.; Sardarpasha, K. R.; Gowda, V. C. Veeranna

2018-05-01

Sm3+ doped lithium di-borate glasses with composition 30Li2O-60B2O3-(10-x) PbO, (where 0 molar volume with samarium ion content indicates the openness of the glass structure. The gradual increase in average separation of boron-boron atoms with VmB clearly indicates deterioration of borate glass network, which in turn leads to decrease in the oxygen packing density. The replacements of Sm2O3 for PbO depolymerise the chain structure and that would increase the concentration of non-bridging oxygens. The marginal increase of optical band gap energy after 1.0 mol.% of Sm2O3 is explained by considering the structural modification in lead-borate. The influence of Sm3+ ion on physical and optical properties in lithium-lead-borate glasses is investigated and the results were discussed in view of the structure of borate glass network.

Corrosion assessment and enhanced biocompatibility analysis of biodegradable magnesium-based alloys

Science.gov (United States)

Pompa, Luis Enrique

Magnesium alloys have raised immense interest to many researchers because of its evolution as a new third generation material. Due to their biocompatibility, density, and mechanical properties, magnesium alloys are frequently reported as prospective biodegradable implant materials. Moreover, magnesium based alloys experience a natural phenomena to biodegrade in aqueous solutions due to its corrosive activity, which is excellent for orthopedic and cardiovascular applications. However, major concerns with such alloys are fast and non-uniform corrosion degradation. Controlling the degradation rate in the physiological environment determines the success of an implant. In this investigation, three grades of magnesium alloys: AZ31B, AZ91E and ZK60A were studied for their corrosion resistance and biocompatibility. Scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy and contact angle meter are used to study surface morphology, chemistry, roughness and wettability, respectively. Additionally, the cytotoxicity of the leached metal ions was evaluated by a tetrazolium based bio-assay, MTS.

Creep and creep rupture properties of unalloyed vanadium and solid-solution-strengthened vanadium-base alloys

International Nuclear Information System (INIS)

Kainuma, T.; Iwao, N.; Suzuki, T.; Watanabe, R.

1982-01-01

The creep and creep rupture properties of vanadium and vanadium-base alloys were studied at 700 and 1000 0 C. The alloys were vanadium-base binary alloys containing about 5 - 21 at.% Al, Ti, Nb, Ta, Cr, Mo or Fe, three V-20wt.%Nb-base ternary alloys containing 5 or 10 wt.% Al, Cr or Mo, V-10wt.%Ta-10wt.%Al and V-25wt.%Cr-0.8wt.%Zr. The creep rupture stress of the binary alloys, except the V-Al and V-Ti alloys, increased linearly with increasing concentration of the alloying elements. The V-Nb alloy had the best properties with respect to the rupture stress and creep rate at 700 0 C and the rupture stress at 1000 0 C, but the V-Mo alloy appeared likely to have better creep properties at longer times and higher temperatures. Of the five ternary alloys, V-20wt.%Nb-5wt.%Cr and V-20wt.%Nb-10wt.%Mo showed the best creep properties. The creep properties of these two alloys were compared with those of other vanadium alloys and of type 316 stainless steel. (Auth.)

Investigation on corrosion and wear behaviors of nanoparticles reinforced Ni-based composite alloying layer

International Nuclear Information System (INIS)

Xu Jiang; Tao Jie; Jiang Shuyun; Xu Zhong

2008-01-01

In order to investigate the role of amorphous SiO 2 particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO 2 particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO 2 was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO 2 particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of γ-phase and amorphous nano-SiO 2 particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO 2 particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite alloying layer was investigated by an electrochemical method in 3.5%NaCl solution. Compared with single alloying layer, the amorphous nano-SiO 2 particles slightly decreased the corrosion resistance of the Ni-Cr-Mo-Cu alloying layer. X-ray photoelectron spectroscopy (XPS) revealed that the passive films formed on the composite alloying consisted of Cr 2 O 3 , MoO 3 , SiO 2 and metallic Ni and Mo. The dry wear test results showed that the composite alloying layer had excellent friction-reduced property, and the wear weight loss of composite alloying layer was less than 60% of that of Ni-Cr-Mo-Cu alloying layer

Thermodynamic Tuning of Mg-Based Hydrogen Storage Alloys: A Review

Science.gov (United States)

Zhu, Min; Lu, Yanshan; Ouyang, Liuzhang; Wang, Hui

2013-01-01

Mg-based hydrides are one of the most promising hydrogen storage materials because of their relatively high storage capacity, abundance, and low cost. However, slow kinetics and stable thermodynamics hinder their practical application. In contrast to the substantial progress in the enhancement of the hydrogenation/dehydrogenation kinetics, thermodynamic tuning is still a great challenge for Mg-based alloys. At present, the main strategies to alter the thermodynamics of Mg/MgH2 are alloying, nanostructuring, and changing the reaction pathway. Using these approaches, thermodynamic tuning has been achieved to some extent, but it is still far from that required for practical application. In this article, we summarize the advantages and disadvantages of these strategies. Based on the current progress, finding reversible systems with high hydrogen capacity and effectively tailored reaction enthalpy offers a promising route for tuning the thermodynamics of Mg-based hydrogen storage alloys. PMID:28788353

Prospects for designing structural cast eutectic alloys on Al-Ce-Ni system base

International Nuclear Information System (INIS)

Belov, N.A.; Naumova, E.S.

1996-01-01

The phase diagram of Al-Ce-Ni system is built for an aluminium corner at component concentration up to 16 mass %Ce and 8 mass%Ni. A ternary eutectic reaction is established at 12%Ce, 5%Ni and 626 deg C. The ternary eutectic alloy is similar in structure to rapidly cooled Al base alloys with transition metals. The possibility to design new cast alloys based on three-phase (Al)+NiAl 3 +CeAl 4 eutectics is under consideration. Al-Zn-Mg-Cu, Al-Sc and Al-Zr base alloys can be used as (Al) constituent of the eutectics. The new alloys may be considered as heat resistant ones due to the fact that no structural changes are observed in castings on heating up to 350 deg C. 18 refs.; 4 figs.; 2 tabs

Surface alloying of nickel based superalloys by laser

International Nuclear Information System (INIS)

Rodriguez, G.P.; Garcia, I.; Damborenea, J.J. de

1998-01-01

Ni based superalloys present a high oxidation resistance at high temperature as well as good mechanical properties. But new technology developments force to research in this materials to improve their properties at high temperature. In this work, two Ni based superalloys (Nimonic 80A and Inconel 600) were surface alloyed with aluminium using a high power laser. SEM and EDX were used to study the microstructure of the obtained coatings. Alloyed specimens were tested at 1.273 K between 24 and 250 h. Results showed the generation of a protective and continuous coating of alumina on the laser treated specimens surface that can improve oxidation resistance. (Author) 8 refs

Dual Microstructure Heat Treatment of a Nickel-Base Disk Alloy

Science.gov (United States)

Gayda, John

2001-01-01

Existing Dual Microstructure Heat Treat (DMHT) technology was successfully applied to Alloy 10, a high strength, nickel-base disk alloy, to produce a disk with a fine grain bore and coarse grain rim. Specimens were extracted from the DMHT disk and tested in tension, creep, fatigue, and crack growth using conditions pertinent to disk applications. These data were then compared with data from "traditional" subsolvus and supersolvus heat treatments for Alloy 10. The results showed the DMHT disk to have a high strength, fatigue resistant bore comparable to that of subsolvus Alloy 10. Further, creep resistance of the DMHT rim was comparable to that of supersolvus Alloy 10. Crack growth resistance in the DMHT rim, while better than that for subsolvus, was inferior to that of supersolvus Alloy 10. The slow cool at the end of the DMHT conversion and/or the subsolvus resolution step are thought to be responsible for degrading rim DMHT crack growth resistance.

Nickel-based materials and high-alloy, special stainless steels. 2. new rev. and enl. ed.

International Nuclear Information System (INIS)

Heubner, U.; Brill, U.; Hoffmann, T.; Jasner, M.; Kirchheiner, R.; Koecher, R.; Richter, H.; Rockel, M.; White, F.

1993-01-01

The book is intended as a source of information on nickel-based materials and special stainless steels and apart from the up-to-date materials data presents information on recent developments and knowledge gained, so that it may be a valuable aid to materials engineers looking for cost-effective resolutions of their materials problems in the chemical process industry, power plant operation, and high-temperature applications. The book presents eight individual contributions entitled as follows: (1) Nickel-base alloys and high-alloy, special stainless steels. - Materials survey and data sheets (Ulrich Heubner). (2) Corrosion of nickel-base alloys and special stainless steels (Manfred Rockel). (3) Welding of nickel-base alloys and high-alloy, special stainless steels (Theo Hoffmann). (4) High-temperature resistant materials (Ulrich Brill). (5) Application and processing of nickel-base materials in the chemical process industry and in pollution abatement equipment (Reiner Koecher). (6) Selected examples of applications of nickel-base materials in chemical plant (Manfred Jasner, Frederick White). (7) Applications of nickel-base alloys and special stainless steels in power plant. (8) The use of nickel-base alloys and stainless steels in pollution abatement processes (R. Kirchheiner). (orig./MM). 151 figs., 226 refs [de

A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

Science.gov (United States)

2017-03-28

AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

Study of superficial films and of electrochemical behaviour of some nickel base alloys and titanium base alloys in solution representation of granitic, argillaceous and salted ground waters

International Nuclear Information System (INIS)

Quang, K.V.; Da Cunha Belo, M.; Benabed, M.S.; Bourelier, F.; Jallerat, N.; Pari, F.L.

1985-01-01

The corrosion behaviour of the stainless steels 304, 316 Ti, 25Cr-20Ni-Mo-Ti, nickel base alloys Hastelloy C4, Inconel 625, Incoloy 800, Ti and Ti-0.2% Pd alloy has been studied in the aerated or deaerated solutions at 20 0 C and 90 0 C whose compositions are representative of interstitial ground waters: granitic or clay waters or salt brine. The electrochemical techniques used are voltametry, polarization resistance and complexe impedance measurements. Electrochemical data show the respective influence of the parameters such as temperature, solution composition and dissolved oxygen, addition of soluble species chloride, fluoride, sulfide and carbonates, on which depend the corrosion current density, the passivation and the pitting potential. The inhibition efficiency of carbonate and bicarbonate activities against pitting corrosion is determined. In clay water at 90 0 C, Ti and Ti-Pd show very high passivation aptitude and a broad passive potential range. Alloying Pd increases cathodic overpotential and also transpassive potential. It makes the alloy less sensitive to the temperature effect. Optical Glow Discharge Spectra show three parts in the composition depth profiles of surface films on alloys. XPS and SIMS spectrometry analyses are also carried out. Electron microscopy observation shows that passive films formed on Ti and Ti-Pd alloy have amorphous structure. Analysis of the alloy constituents dissolved in solutions, by radioactivation in neutrons, gives the order of magnitude of the Ni base alloy corrosion rates in various media. It also points out the preferential dissolution of alloying iron and in certain cases of chromium

Preparation and examination of properties of samarium-153-EDTMP complex; Otrzymywanie chelatu kwasu etylenodiaminotetrametylenofosfonowego (EDTMP) z samarem-153 i badanie jego wlasciwosci

Energy Technology Data Exchange (ETDEWEB)

Nowak, M. [Institute of Atomic Energy, Otwock-Swierk (Poland); Garnuszek, P.; Lukasiewicz, A.; Wozniak, I.; Zulczyk, W. [Osrodek Badawczo-Rozwojowy Izotopow, Otwock-Swierk (Poland); Licinska, I. [Instytut Lekow, Warsaw (Poland)

1995-12-31

Preparation and properties of ethylenediaminetetramethylenephosphonic acid (EDTMP) as well as some properties of {sup 153}Sm-EDTMP chelate have been examined. The chelate formed by samarium-153 (46.3 h, {beta}{sup -}-decay) with EDTMP exhibits high bone uptake and can be used for treatment of disseminated, painful skeletal metastases. The purity and stability of solutions of {sup 153}Sm-EDTMP chelate were examined in a broad range of samarium concentration and {sup 153}Sm specific activity. The complex under study was examined by radio-TLC, -electrophoresis and radio-HPLC. The results obtained suggest the small size of molecules of {sup 153}Sm-EDTMP chelate as compared with molecules of ``free``EDTMP. The results of biodistribution of {sup 153}Sm-EDTMP determined in rats indicate the quick blood clearance, high deposition of radioactivity in bone and quick excretion of radioactivity into urine. No specific uptake of {sup 153}Sm-EDTMP in extra-skeletal organs was found. (author). 42 refs, 13 figs, 22 tabs.

Shape-Memory Effect and Pseudoelasticity in Fe-Mn-Based Alloys

Science.gov (United States)

La Roca, P.; Baruj, A.; Sade, M.

2017-03-01

Several Fe-based alloys are being considered as potential candidates for applications which require shape-memory behavior or superelastic properties. The possibility of using fabrication methods which are well known in the steel industry is very attractive and encourages a large amount of research in the field. In the present article, Fe-Mn-based alloys are mainly addressed. On the one hand, attention is paid to the shape-memory effect where the alloys contain (a) a maximum amount of Mn up to around 30 wt%, (b) several possible substitutional elements like Si, Cr, Ni, Co, and Nb and (c) some possible interstitial elements like C. On the other hand, superelastic alloys are analyzed, mainly the Fe-Mn-Al-Ni system discovered a few years ago. The most noticeable properties resulting from the martensitic transformations which are responsible for the mentioned properties, i.e., the fcc-hcp in the first case and the bcc-fcc in the latter are discussed. Selected potential applications are also analyzed.

Tuning the activity of Pt alloy electrocatalysts by means of the lanthanide contraction

DEFF Research Database (Denmark)

Escribano, Maria Escudero; Malacrida, Paolo; Hansen, Martin Hangaard

2016-01-01

is lanthanum, cerium, samarium, gadolinium, terbium, dysprosium, thulium, or calcium. The materials are among the most active polycrystalline Pt-based catalysts reported, presenting activity enhancement by a factor of 3 to 6 over Pt. The active phase consists of a Pt overlayer formed by acid leaching. The ORR...

Technical assessment of niobium alloys data base for fusion reactor applications

Energy Technology Data Exchange (ETDEWEB)

Pionke, L J; Davis, J W

1979-08-01

Refractory metals are one class of material to be developed in the Alloy Development For Irradiation Performance (ADIP) program recently initiated. A principal purpose of the assessment reported herein is to establish the existing data base for niobium alloys in order to help guide the work to be performed in the ADIP program. Major ADIP decisions include alloy selection/modification and irradiated/unirradiated material testing. This Assessment addressed the topics of: (1) niobium alloy development history and niobium metallurgy, (2) unirradiated mechanical properties, (3) irradiated properties, (4) corrosion, and (5) environmental effects.

Green inhibitors. Rare Earth based systems

International Nuclear Information System (INIS)

Aballe, A.; Bethencourt, M.; Botana, F.J.; Perez, J.; Rodriguez, M.A.; Marcos, M.

1997-01-01

Lanthanum, Cerium and Samarium chlorides have been investigated as uniform and pitting corrosion inhibitors of AISI 434 and AISI 304 stainless steels and AA 5083 Al-Mg alloy in 3.5% Na Cl aerated aqueous solutions. Their inhibitor power was evaluated by using electrochemical techniques such as Linear and Cyclic Polarisation. In each case, the highest protection degree was found in the solution dropped with 500 ppm of CeCl 3 . Similar results were obtained for additions of 500 ppm of LaCl 3 . Scanning Electron Microscopy and Energy Dispersive Spectroscopy allowed us to confirm the cathodic nature of the inhibition process. (Author) 27 refs

Replacement of Co-base alloy for radiation exposure reduction in the primary system of PWR

International Nuclear Information System (INIS)

Han, Jeong Ho; Nyo, Kye Ho; Lee, Deok Hyun; Lim, Deok Jae; Ahn, Jin Keun; Kim, Sun Jin

1996-01-01

Of numerous Co-free alloys developed to replace Co-base stellite used in valve hardfacing material, two iron-base alloys of Armacor M and Tristelle 5183 and one nickel-base alloy of Nucalloy 488 were selected as candidate Co-free alloys, and Stellite 6 was also selected as a standard hardfacing material. These four alloys were welded on 316SS substrate using TIG welding method. The first corrosion test loop of KAERI simulating the water chemistry and operation condition of the primary system of PWR was designed and fabricated. Corrosion behaviors of the above four kinds of alloys were evaluated using this test loop under the condition of 300 deg C, 1500 psi. Microstructures of weldment of these alloys were observed to identify both matrix and secondary phase in each weldment. Hardnesses of weld deposit layer including HAZ and substrate were measured using micro-Vickers hardness tester. The status on the technology of Co-base alloy replacement in valve components was reviewed with respect to the classification of valves to be replaced, the development of Co-free alloys, the application of Co-free alloys and its experiences in foreign NPPs, and the Co reduction program in domestic NPPs and industries. 18 tabs., 20 figs., 22 refs. (Author)

Elastic characteristics and microplastic deformation of amorphous alloys on iron base

Energy Technology Data Exchange (ETDEWEB)

Pol' dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret' yakov, B.N. (Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR))

1983-01-01

Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit sigmasub(0.01) and yield limit sigmasub(0.2)) of three amorphous alloys on iron base Fe/sub 80/B/sub 20/, Fe/sub 70/Cr/sub 10/B/sub 20/ and Fe/sub 70/Cr/sub 5/Ni/sub 5/B/sub 20/ are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials.

Effects of thermal aging on microstructures of low alloy steel–Ni base alloy dissimilar metal weld interfaces

International Nuclear Information System (INIS)

Choi, Kyoung Joon; Kim, Jong Jin; Lee, Bong Ho; Bahn, Chi Bum; Kim, Ji Hyun

2013-01-01

In this study, the advanced instrumental analysis has been performed to investigate the effect of long-term thermal aging on the microstructural evolution in the fusion boundary region between weld metal and low alloy steel in dissimilar metal welds. A representative dissimilar weld mock-up made of Alloy 690-Alloy 152-A533 Gr. B was fabricated and aged at 450 °C for 2750 h. The micro- and nano-scale characterization were conducted mainly near in a weld root region by using optical microscopy, scanning electron microscopy, transmission electron microscopy, and three dimensional atom probe tomography. It was observed that the weld root was generally divided into several regions including dilution zone in the Ni-base alloy weld metal, fusion boundary, and heat-affected zone in the low alloy steel. A steep gradient was shown in the chemical composition profile across the interface between A533 Gr. B and Alloy 152. The precipitation of carbides was also observed along and near the fusion boundary of as-welded and aged dissimilar metal joints. It was also found that the precipitation of Cr carbides was enhanced by the thermal aging near the fusion boundary

Effects of thermal aging on microstructures of low alloy steel–Ni base alloy dissimilar metal weld interfaces

Energy Technology Data Exchange (ETDEWEB)

Choi, Kyoung Joon; Kim, Jong Jin [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Lee, Bong Ho [National Center for Nanomaterials Technology (NCNT), Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Bahn, Chi Bum [Argonne National Laboratory, 9700 S. Cass Ave, Lemont, IL 60439 (United States); Kim, Ji Hyun, E-mail: kimjh@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

2013-10-15

In this study, the advanced instrumental analysis has been performed to investigate the effect of long-term thermal aging on the microstructural evolution in the fusion boundary region between weld metal and low alloy steel in dissimilar metal welds. A representative dissimilar weld mock-up made of Alloy 690-Alloy 152-A533 Gr. B was fabricated and aged at 450 °C for 2750 h. The micro- and nano-scale characterization were conducted mainly near in a weld root region by using optical microscopy, scanning electron microscopy, transmission electron microscopy, and three dimensional atom probe tomography. It was observed that the weld root was generally divided into several regions including dilution zone in the Ni-base alloy weld metal, fusion boundary, and heat-affected zone in the low alloy steel. A steep gradient was shown in the chemical composition profile across the interface between A533 Gr. B and Alloy 152. The precipitation of carbides was also observed along and near the fusion boundary of as-welded and aged dissimilar metal joints. It was also found that the precipitation of Cr carbides was enhanced by the thermal aging near the fusion boundary.

Reliability of copper based alloys for electric resistance spot welding

International Nuclear Information System (INIS)

Jovanovicj, M.; Mihajlovicj, A.; Sherbedzhija, B.

1977-01-01

Durability of copper based alloys (B-5 and B-6) for electric resistance spot-welding was examined. The total amount of Be, Ni and Zr was up to 2 and 1 wt.% respectively. Good durability and satisfactory quality of welded spots were obtained in previous laboratory experiments carried out on the fixed spot-welding machine of an industrial type (only B-5 alloy was examined). Electrodes made of both B-5 and B-6 alloy were tested on spot-welding grips and fixed spot-welding machines in Tvornica automobila Sarajevo (TAS). The obtained results suggest that the durability of electrodes made of B-5 and B-6 alloys is more than twice better than of that used in TAS

Mechanical properties of soldered joints of niobium base alloys

International Nuclear Information System (INIS)

Grishin, V.L.

1980-01-01

Mechanical properties of soldered joints of niobium alloys widely distributed in industry: VN3, VN4, VN5A, VN5AE, VN5AEP etc., 0.6-1.2 mm thick are investigated. It is found out that the usage of zirconium-vanadium, titanium-tantalum solders for welding niobium base alloys permits to obtain soldered joints with satisfactory mechanical properties at elevated temperatures

Effects of Cr and Nb contents on the susceptibility of Alloy 600 type Ni-base alloys to stress-corrosion cracking in a simulated BWR environment

International Nuclear Information System (INIS)

Akashi, Masatsune

1995-01-01

In order to discuss the effects of chromium and niobium contents on the susceptibility of Alloy 600 type nickel-base alloys to stress-corrosion cracking in the BWR primary coolant environment, a series of creviced bent-beam (CBB) tests were conducted in a high-temperature, high-purity water environment. Chromium, niobium, and titanium as alloying elements improved the resistivity to stress-corrosion cracking, whereas carbon enhanced the susceptibility to it. Alloy-chemistry-based correlations have been defined to predict the relative resistances of alloys to stress-corrosion cracking. A strong correlation was found, for several heats of alloys, between grain-boundary chromium depletion and the susceptibility to stress-corrosion cracking

Galvanic corrosion resistance of welded dissimilar nickel-base alloys

International Nuclear Information System (INIS)

Corbett, R.A.; Morrison, W.S.; Snyder, R.J.

1986-01-01

A program for evaluating the corrosion resistance of various dissimilar welded nickel-base alloy combinations is outlined. Alloy combinations included ALLCORR, Hastelloy C-276, Inconel 72 and Inconel 690. The GTAW welding process involved both high and minimum heat in-put conditions. Samples were evaluated in the as-welded condition, as well as after having been aged at various condtions of time and temperature. These were judged to be most representative of process upset conditions which might be expected. Corrosion testing evaluated resistance to an oxidizing acid and a severe service environment in which the alloy combinations might be used. Mechanical properties are also discussed

Potentiometric study of samarium oxides formation from its chloride in a molten eutectic mixture of sodium and cesium chlorides

International Nuclear Information System (INIS)

Smolenskij, V.V.; Bove, A.L.; Del'mukhamedov, R.D.; Borodina, N.P.; Gavrilov, A.G.

1997-01-01

Interaction of trivalent samarium cations with oxide-ions in NaCl-2CsCl melt at 973 K has been studied by potentiometric method using electrochemical cell with two platinum-oxygen electrodes with a solid electrolyte membrane. The mechanism of the interaction and composition of the reaction products, depending on the medium oxyacidity, have been considered. Certain thermodynamic characteristics of the process have been calculated

Fabrication of polymer-alloy based on polytetrafluoroethylene by radiation-crosslinking

International Nuclear Information System (INIS)

Oshima, A.; Asano, S.; Hyunga, T.; Ichizuri, S.; Washio, M.

2003-01-01

Perfluoropolymer such as polytetrafluoroethylene (PTFE), tetrafluoroethylene co-perfluoroalkylvinylether (PFA) and tetrafluoroethylene-co-hexafluoropropylene (FFP) have been classified to be a typical polymer of radiation-induced degradation. However, we confirmed that the crosslinking of PTFE, PFA and FEP proceed by irradiation under selective condition where oxygen-free and high temperature above the melting temperature of them. In this study, fabrication of polymer-alloy based on PTFE has been demonstrated by radiation-crosslinking techniques. The polymer alloy, which was PTFE fine powder contained with other polymeric materials, was obtained by electron beams irradiation under oxygen-free atmosphere. Characterization of polymer-alloy based on PTFE has been studied by various measurements such as solid state 19F- and 13C-NMR spectroscopy, thermal analysis (DSC, TGA)

Structural phase transition and electronic properties in samarium chalcogenides

Energy Technology Data Exchange (ETDEWEB)

Panwar, Y. S., E-mail: yspanwar2011@gmail.com [Department of Physics, Govt. New Science College Dewas-455001 (India); Aynyas, Mahendra [Department of Physics, C.S.A. Govt. P.G. College, Sehore, 466001 (India); Pataiya, J.; Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal, 462026 (India)

2016-05-06

The electronic structure and high pressure properties of samarium monochalcogenides SmS, SmSe and SmTe have been reported by using tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA). The total energy as a function of volume is evaluated. It is found that these monochalcogenides are stable in NaCl-type structure under ambient pressure. We predict a structural phase transition from NaCl-type (B{sub 1}-phase) structure to CsCl-type (B{sub 2}-type) structure for these compounds. Phase transition pressures were found to be 1.7, 4.4 and 6.6 GPa, for SmS, SmSe and SmTe respectively. Apart from this, the lattice parameter (a{sub 0}), bulk modulus (B{sub 0}), band structure (BS) and density of states (DOS) are calculated. From energy band diagram we observed that these compounds exhibit metallic character. The calculated values of equilibrium lattice parameter and phase transition pressure are in general good agreement with available data.

Multi-step wrought processing of TiAl-based alloys

International Nuclear Information System (INIS)

Fuchs, G.E.

1997-04-01

Wrought processing will likely be needed for fabrication of a variety of TiAl-based alloy structural components. Laboratory and development work has usually relied on one-step forging to produce test material. Attempts to scale-up TiAl-based alloy processing has indicated that multi-step wrought processing is necessary. The purpose of this study was to examine potential multi-step processing routes, such as two-step isothermal forging and extrusion + isothermal forging. The effects of processing (I/M versus P/M), intermediate recrystallization heat treatments and processing route on the tensile and creep properties of Ti-48Al-2Nb-2Cr alloys were examined. The results of the testing were then compared to samples from the same heats of materials processed by one-step routes. Finally, by evaluating the effect of processing on microstructure and properties, optimized and potentially lower cost processing routes could be identified

Precipitation sequence and kinetics in a Mg-4Sm-1Zn-0.4Zr (wt%) alloy

Energy Technology Data Exchange (ETDEWEB)

Xia, Xiangyu, E-mail: xxia5@wisc.edu [Materials Science Program, University of Wisconsin – Madison, 1509 University Ave., Madison, WI 53706 (United States); Department of Materials Science and Engineering, University of Wisconsin – Madison, 1509 University Ave, Madison, WI 53706 (United States); Luo, Alan A. [Department of Materials Science and Engineering, University of Wisconsin – Madison, 1509 University Ave, Madison, WI 53706 (United States); Department of Materials Science and Engineering, The Ohio State University, 116 W. 19th Ave, Columbus, OH 43210 (United States); Stone, Donald S. [Materials Science Program, University of Wisconsin – Madison, 1509 University Ave., Madison, WI 53706 (United States); Department of Materials Science and Engineering, University of Wisconsin – Madison, 1509 University Ave, Madison, WI 53706 (United States)

2015-11-15

The present research presents a series of investigations into phase identification and precipitation sequence in Mg-4Sm-1Zn-0.4Zr alloy, using differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The precipitation sequence is: super saturated solid solution (S.S.S.S) → solute atom clusters → γ″ → γ′ (→stacking faults) → γ. Structure of γ″ has been determined as an ordered hexagonal GP zone, a = 0.556 nm, c = 0.414 nm γ′ is composed of several γ″ layers. Kinetic studies show that quenched-in vacancies play an important role in the formation of solute clusters, while the growth of both precipitates are diffusion controlled. Analysis of microstructure evolution suggests that nucleation of γ′ happens near existing γ″ precipitates. - Highlights: • Precipitation sequence in a high-zinc magnesium-samarium-zinc-zirconium alloy has been identified. • Structures of metastable precipitates are modified directly with HAADF-STEM. • Kinetic calculations were performed to understand nucleation/growth mechanisms of these precipitates.

On the superconductivity of vanadium based alloys

International Nuclear Information System (INIS)

Brouers, F.; Rest, J.V. der

1985-01-01

We have computed the electron density of States of solid solutions of vanadium based transition metal alloys V 90 X 10 by using the tight-binding recursion method for degenerate d-bands in order to calculte the alloy superconducting transition temperature with the McMillan formula. As observed experimentally for X on the left hand side of V in the periodic table one obtains an increase of T c while for X on the right hand side of V the critical temperature decreases. The detailed comparison with experiments indicate that when the bandwidths of the two constituents are different, one cannot neglect the variation of the electron-phonon interactions. (author) [pt

Fabrication and study of double sintered TiNi-based porous alloys

Science.gov (United States)

Sergey, Anikeev; Valentina, Hodorenko; Timofey, Chekalkin; Victor, Gunther; Ji-hoon, Kang; Ji-soon, Kim

2017-05-01

Double-sintered porous TiNi-based alloys were fabricated and their structural characteristics and physico-mechanical properties were investigated. A fabrication technology of powder mixtures is elaborated in this article. Sintering conditions were chosen experimentally to ensure good structure and properties. The porous alloys were synthesized by solid-state double diffusion sintering (DDS) of Ti-Ni powder and prepare to obtain dense, crack-free, and homogeneous samples. The Ti-Ni compound sintered at various temperatures was investigated by scanning electron microscopy. Phase composition of the sintered alloys was determined by x-ray diffraction. Analysis of the data confirmed the morphology and structural parameters. Mechanical and physical properties of the sintered alloys were evaluated. DDS at 1250 °C was found to be optimal to produce porous samples with a porosity of 56% and mean pore size of 90 μm. Pore size distribution was unimodal within the narrow range of values. The alloys present enhanced strength and ductility, owing to both the homogeneity of the macrostructure and relative elasticity of the bulk, which is hardened by the Ni-rich precipitates. These results suggest the possibility to manufacture porous TiNi-based alloys for application as a new class of dental implants.

Glass-forming ability and crystallization behavior of some binary and ternary Ni-based glassy alloys

International Nuclear Information System (INIS)

Louzguine-Luzgin, Dmitri V.; Louzguina-Luzgina, Larissa V.; Xie Guoqiang; Li Song; Zhang Wei; Inoue, Akihisa

2008-01-01

The purpose of the current paper is to study the influence of Ti, V, Nb, Al, Sn and Pd additions on the glass-forming ability, formation of a supercooled liquid region and a devitrification process of some Ni-Zr glassy alloys as well as to compare the results with those obtained for similar Cu-based alloys studied earlier. The Ni-based glassy alloys were investigated by using X-ray diffraction, differential scanning and isothermal calorimetries. Although the studied Ni-based alloys showed high values of the reduced glass-transition temperature of about 0.6, their glass-forming ability is quite low. This fact may be explained by low stability of the supercooled liquid against crystallization and formation of the equilibrium intermetallic compounds with a high growth rate compared to those observed in similar Cu-based alloys studied earlier. Relatively low thermal conductivity of Ni-based alloys is also found to be another factor limiting their glass-forming ability

Sorption of samarium in iron (II) and (III) phosphates in aqueous systems; Sorcion de samario en fosfatos de hierro (II) y (III) en sistemas acuosos

Energy Technology Data Exchange (ETDEWEB)

Diaz F, J C

2006-07-01

The radioactive residues that are stored in the radioactive confinements its need to stay isolated of the environment while the radioactivity levels be noxious. An important mechanism by which the radioactive residues can to reach the environment, it is the migration of these through the underground water. That it makes necessary the investigation of reactive materials that interacting with those radionuclides and that its are able to remove them from the watery resources. The synthesis and characterization of materials that can be useful in Environmental Chemistry are very important because its characteristics are exposed and its behavior in chemical phenomena as the sorption watery medium is necessary to use it in the environmental protection. In this work it was carried out the sorption study of the samarium III ion in the iron (II) and (III) phosphate; obtaining the sorption isotherms in function of pH, of the phosphate mass and of the concentration of the samarium ion using UV-visible spectroscopy to determine the removal percentage. The developed experiments show that as much the ferrous phosphate as the ferric phosphate present a great affinity by the samarium III, for what it use like reactive material in contention walls can be very viable because it sorption capacity has overcome 90% to pH values similar to those of the underground and also mentioning that the form to obtain these materials is very economic and simple. (Author)

Discontinuous precipitation in copper base alloys

Indian Academy of Sciences (India)

Discontinuous precipitation (DP) is associated with grain boundary migration in the wake of which alternate plates of the precipitate and the depleted matrix form. Some copper base alloys show DP while others do not. In this paper the misfit strain parameter, , has been calculated and predicted that if 100 > ± 0.1, DP is ...

Effects of Alloying Elements on Room and High Temperature Tensile Properties of Al-Si Cu-Mg Base Alloys =

Science.gov (United States)

Alyaldin, Loay

In recent years, aluminum and aluminum alloys have been widely used in automotive and aerospace industries. Among the most commonly used cast aluminum alloys are those belonging to the Al-Si system. Due to their mechanical properties, light weight, excellent castability and corrosion resistance, these alloys are primarily used in engineering and in automotive applications. The more aluminum is used in the production of a vehicle, the less the weight of the vehicle, and the less fuel it consumes, thereby reducing the amount of harmful emissions into the atmosphere. The principal alloying elements in Al-Si alloys, in addition to silicon, are magnesium and copper which, through the formation of Al2Cu and Mg2Si precipitates, improve the alloy strength via precipitation hardening following heat treatment. However, most Al-Si alloys are not suitable for high temperature applications because their tensile and fatigue strengths are not as high as desired in the temperature range 230-350°C, which are the temperatures that are often attained in automotive engine components under actual service conditions. The main challenge lies in the fact that the strength of heat-treatable cast aluminum alloys decreases at temperatures above 200°C. The strength of alloys under high temperature conditions is improved by obtaining a microstructure containing thermally stable and coarsening-resistant intermetallics, which may be achieved with the addition of Ni. Zr and Sc. Nickel leads to the formation of nickel aluminide Al3Ni and Al 9FeNi in the presence of iron, while zirconium forms Al3Zr. These intermetallics improve the high temperature strength of Al-Si alloys. Some interesting improvements have been achieved by modifying the composition of the base alloy with additions of Mn, resulting in an increase in strength and ductility at both room and high temperatures. Al-Si-Cu-Mg alloys such as the 354 (Al-9wt%Si-1.8wt%Cu-0.5wt%Mg) alloys show a greater response to heat treatment as a

High temperature oxidation and electrochemical investigations on nickel-base alloys

International Nuclear Information System (INIS)

Obigodi-Ndjeng, Georgia

2011-01-01

This study examined high-temperature oxidation behavior of different Ni-base alloys. In addition, electrochemical characterization of the alloy's corrosion behavior was carried out, including comparison of the properties of native passive films grown at room temperature and high temperature oxide scales. PWA 1483 (single-crystalline Ni-base superalloy) and model alloys Ni-Cr-X (where X is either Co or Al) were oxidized at 800 and 900 C in air for different time periods. The superalloy showed the best oxidation behavior at both temperatures, which might be due to the fact that the oxidation growth function is subparabolic for the model alloys and parabolic for the superalloy at 800 C. At higher temperatures, changes in the kinetics are induced, as the oxides grow faster, thus only PWA 1483 growth follows the parabolic law. Different scales in a typical sandwich form were detected, with the inner layer comprised of mostly Cr 2 O 3 , the middle layer was mixture of different oxides and spinels, depending on the alloying elements, and the oxide at the interface oxygen/oxide was found to be NiO. The influence of sample preparation could also be shown, as rougher surfaces change the oxidation kinetics from parabolic and subparabolic for polished samples to linear. The influence of moisture on the oxidation behavior of the 2 nd generation single crystal Ni-base superalloys (PWA 1484, PWA 1487, CMSX 4, Rene N5 and Rene N5+) was studied at 1000 C after 100 h oxidation period. It was found that the moisture increased the oxidation rate and mostly the transient oxides growth rate. The water vapor content in air also influenced the behavior of these alloys, as they showed a higher mass gain in air + 30% water vapor than in air + 10% water vapor. The alloys PWA 1484 and CMSX 4 showed respectively the worst and best behavior in all the studied atmospheres. The addition of reactive elements, such as Yttrium, Hafnium and Lanthanum is likely to enhance the oxidation behavior of PWA

Hydrogen storage in binary and ternary Mg-based alloys. A comprehensive experimental study

Energy Technology Data Exchange (ETDEWEB)

Kalisvaart, W.P.; Harrower, C.T.; Haagsma, J.; Zahiri, B.; Luber, E.J.; Ophus, C.; Miltin, D. [Alberta Univ., Edmonton (Canada); Poirier, E.; Fritzsche, H. [Canadian Neutron Beam Centre, Chalk River, ON (Canada)

2010-07-01

This study focuses on hydrogen sorption properties of cosputtered 1.5 micrometer thick Mg-based films with Al, Fe and Ti as alloying elements. We show that ternary Mg-Al-Ti and Mg-Fe-Ti alloys in particular display remarkable sorption behavior: at 200 C, the films are capable of absorbing 4-6 wt.% hydrogen in seconds, and desorbing in minutes. Furthermore, this sorption behavior is stable for over 100 ab- and desorption cycles for Mg-Al-Ti and Mg-Fe-Ti alloys. No degradation in capacity or kinetics is observed. Based on these observations, some general design principles for Mg-based hydrogen storage alloys are suggested. For Mg-Fe-Ti, encouraging preliminary results on multilayered systems are also presented. (orig.)

Separation of lanthanum from samarium on solid aluminum electrode in LiCl-KCl eutectic melts

International Nuclear Information System (INIS)

De-Bin Ji; Mi-Lin Zhang; Xing Li; Xiao-Yan Jing; Wei Han; Yong-De Yan; Yun Xue; Zhi-Jian Zhang; Harbin Engineering University, Harbin

2015-01-01

This paper presents an electrochemical study on the separation of lanthanum from samarium on aluminum electrode at 773 K. The results from different electrochemical methods showed that Sm(III) and La(III) formed Al-Sm and Al-La intermetallic compounds on an aluminum electrode at electrode potential around -1.67 and -1.46 V, respectively. The electrochemical separation of lanthanum was carried out in LiCl-KCl-LaCl 3 -SmCl 3 melts on solid aluminum electrodes at 773 K by potentiostatic electrolysis at -1.45 V for 40 h and the separation efficiency was 99.1 %. (author)

Determination of trace impurities in iron-based alloy using neutron activation analysis

International Nuclear Information System (INIS)

Zaidi, J.H.; Waheed, S.; Ahmad, S.

2000-01-01

A radiochemical neutron activation analysis procedure has been developed and applied to investigate 40 major, minor, and trace impurities in iron-based alloy. A comparison of RNAA and INAA indicated a significant improvement in the detection limits. The extensive use of these alloys in the heavy mechanical industry, manufacturing of aircraft engines, nuclear applications, medical devices and chemical equipment requires their precise characterization. The concentration of iron in the iron-based alloy was found to be 86.7%, whereas Ca, Cr, K, Mg, Mn, V and W were the other constituents of the alloy, which constituted to around 12.89%. The rest of the elements were present in minor or trace levels. Most of the rare earth elements were also present in trace amounts. (orig.)

Plate-shaped transformation products in zirconium-base alloys

International Nuclear Information System (INIS)

Banerjee, S.; Dey, G.K.; Srivastava, D.

1997-01-01

Plate-shaped products resulting from martensitic, diffusional, and mixed mode transformations in zirconium-base alloys are compared in the present study. These alloys are particularly suitable for the comparison in view of the fact that the lattice correspondence between the parent β (bcc) and the product α (hcp) or γ-hydride (fct) phases are remarkably similar for different types of transformations. Crystallographic features such as orientation relations, habit planes, and interface structures associated with these transformations have been compared, with a view toward examining whether the transformation mechanisms have characteristic imprints on these experimental observables

Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys

Energy Technology Data Exchange (ETDEWEB)

Kalay, Yunus Eren [Iowa State Univ., Ames, IA (United States)

2009-01-01

Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current dissertation involves an extensive set of experimental, analytical, and computational studies designed to increase the overall understanding of morphological selection, phase competition, and structural hierarchy that occurs under far-from equilibrium conditions. High pressure gas atomization and Cu-block melt-spinning are the two different rapid solidification techniques applied in this study. The research is mainly focused on Al-Si and Al-Sm alloy systems. Silicon and samarium produce different, yet favorable, systems for exploration when alloyed with aluminum under far-from equilibrium conditions. One of the main differences comes from the positions of their respective T₀ curves, which makes Al-Si a good candidate for solubility extension while the plunging T₀ line in Al-Sm promotes glass formation. The rapidly solidified gas-atomized Al-Si powders within a composition range of 15 to 50 wt% Si are examined using scanning and transmission electron microscopy. The non-equilibrium partitioning and morphological selection observed by examining powders at different size classes are described via a microstructure map. The interface velocities and the amount of undercooling present in the powders are estimated from measured eutectic spacings based on Jackson-Hunt (JH) and Trivedi-Magnin-Kurz (TMK) models, which permit a direct comparison of theoretical predictions. For an average particle size of 10 {micro}m with a Peclet number of ~0.2, JH and TMK deviate from

Ductile-phase toughening and fatigue crack growth in Nb3Al base alloys

International Nuclear Information System (INIS)

Gnanamoorthy, R.; Hanada, S.

1996-01-01

Niobium aluminide (Nb 3 Al) base intermetallic compounds exhibit good high-temperature strength and creep properties and potential for applications above 1,200 C provided their inadequately low room-temperature ductility, fracture toughness and fatigue crack growth behavior are improved. Addition of tantalum to Nb 3 Al base materials improves the high-temperature strength significantly and seems to be a potential alloying element. In the present study, room temperature fracture toughness and fatigue crack growth behavior of tantalum alloyed Nb 3 Al base alloy prepared by ingot metallurgy are investigated

Cobalt-based orthopaedic alloys: Relationship between forming route, microstructure and tribological performance

Energy Technology Data Exchange (ETDEWEB)

Patel, Bhairav [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Favaro, Gregory [CSM Instruments SA, Rue de la Gare 4, Galileo Center, CH-2034 Peseux (Switzerland); Inam, Fawad [Advanced Composite Training and Development Centre and School of Mechanical and Aeronautical Engineering, Glyndwr University, Mold Road, Wrexham LL11 2AW (United Kingdom); School of Engineering and Materials Science and Nanoforce Technology Ltd, Queen Mary University of London, London E1 4NS (United Kingdom); Reece, Michael J. [School of Engineering and Materials Science and Nanoforce Technology Ltd, Queen Mary University of London, London E1 4NS (United Kingdom); Angadji, Arash [Orthopaedic Research UK, Furlong House, 10a Chandos Street, London W1G 9DQ (United Kingdom); Bonfield, William [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Huang, Jie [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom); Edirisinghe, Mohan, E-mail: m.edirisinghe@ucl.ac.uk [Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

2012-07-01

The average longevity of hip replacement devices is approximately 10-15 years, which generally depends on many factors. But for younger generation patients this would mean that revisions may be required at some stage in order to maintain functional activity. Therefore, research is required to increase the longevity to around 25-30 years; a target that was initially set by John Charnley. The main issues related to metal-on-metal (MoM) hip replacement devices are the high wear rates when malpositioned and the release of metallic ions into the blood stream and surrounding tissues. Work is required to reduce the wear rates and limit the amount of metallic ions being leached out of the current MoM materials, to be able to produce an ideal hip replacement material. The most commonly used MoM material is the cobalt-based alloys, more specifically ASTM F75, due to their excellent wear and corrosion resistance. They are either fabricated using the cast or wrought method, however powder processing of these alloys has been shown to improve the properties. One powder processing technique used is spark plasma sintering, which utilises electric current Joule heating to produce high heating rates to sinter powders to form an alloy. Two conventionally manufactured alloys (ASTM F75 and ASTM F1537) and a spark plasma sintered (SPS) alloy were evaluated for their microstructure, hardness, tribological performance and the release of metallic content. The SPS alloy with oxides and not carbides in its microstructure had the higher hardness, which resulted in the lowest wear and friction coefficient, with lower amounts of chromium and molybdenum detected from the wear debris compared to the ASTM F75 and ASTM F1537. In addition the wear debris size and size distribution of the SPS alloy generated were considerably small, indicating a material that exhibits excellent performance and more favourable compared to the current conventional cobalt based alloys used in orthopaedics. - Highlights

EXAFS investigation on microstructure of La-based alloy deuteride

CERN Document Server

Chen Bo Fei; Xie Chao Mei; Chen Xi Ping; Liu Li Juan; Xie Ya Ning; Hu Tian Dou; Zhang Jing

2002-01-01

Extended X-ray absorption fine structure (EXAFS) spectra were measured to investigate the microstructure of La-based alloy deuteride. The radial structural functions of LaNi sub 4 sub . sub 2 sub 5 Al sub 0 sub . sub 7 sub 5 D sub x samples were obtained and the comparisons among different samples were performed. The results show that removal of deuterium is fast in La-Ni-Al hydrogen storage alloys under non-airtight condition

Structural and luminescence properties of samarium doped lead alumino borate glasses

Science.gov (United States)

Mohan, Shaweta; Kaur, Simranpreet; Singh, D. P.; Kaur, Puneet

2017-11-01

The study reports the effect of samarium concentration on the physical, structural and spectroscopic characteristics of samarium doped lead alumino borate glasses having composition 20PbO-(10-x)Al2O3-70B2O3-xSm2O3; x = 0.1, 0.5, 1.0 and 2.0 mol %. The glasses were fabricated by conventional melt-quenching technique and then characterized by XRD, FTIR, optical absorption and fluorescence spectra. X-ray diffraction studies confirmed the amorphous nature of the prepared glasses. FTIR spectra indicate the presence of BO3, BO4, AlO6 and a few other structural groups. Various physical properties such as density, molar volume, refractive index, rare earth ion concentration, boron-boron distance and polarizability etc. were determined using conventional methods and standard formulae. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. The value of Ω2 was found to be highest for glass with 1 mol% Sm2O3 and attributed to the asymmetry of the ligand field at the rare earth ion site and the rare earth oxygen (Sm-O) covalency. The calculated intensity parameters and fluorescence spectra were further used to predict the radiative transition probability (A), radiative lifetime (τR), branching ratio (βR), peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σ) for the characteristic 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 transitions of the Sm3+ ion. Concentration quenching was observed for 2 mol% concentration of Sm2O3 and ascribed to energy transfer through various cross-relaxation channels between Sm3+ ions. Reasonably high values of branching ratios and stimulated emission cross-section for the prepared glasses points towards their utility in the development of visible lasers emitting in the reddish-orange spectral region. However, the glass with 1 mol% Sm2O3 was found to show better radiative properties.

Effect of heat treatment on the microstructure and properties of Ni based soft magnetic alloy.

Science.gov (United States)

Li, Chunhong; Ruan, Hui; Chen, Dengming; Li, Kejian; Guo, Donglin; Shao, Bin

2018-04-20

A Ni-based alloy was heat treated by changing the temperature and ambient atmosphere of the heat treatment. Morphology, crystal structure, and physical performance of the Ni-based alloy were characterized via SEM, XRD, TEM, and PPMS. Results show that due to the heat treatment process, the grain growth of the Ni-based alloy and the removal of impurities and defects are promoted. Both the orientation and stress caused by rolling are reduced. The permeability and saturation magnetization of the alloy are improved. The hysteresis loss and coercivity are decreased. Higher heat treatment temperature leads to increased improvement of permeability and saturation magnetization. Heat treatment in hydrogen is more conducive to the removal of impurities. At the same temperature, the magnetic performance of the heat-treated alloy in hydrogen is better than that of an alloy with heat treatment in vacuum. The Ni-based alloy shows an excellent magnetic performance on 1,373 K heat treatment in hydrogen atmosphere. In this process, the µ m , B s , P u , and H c of the obtained alloy are 427 mHm -1 , 509 mT, 0.866 Jm -3 , and 0.514 Am -1 , respectively. At the same time, the resistivity of alloy decreases and its thermal conductivity increases in response to heat treatment. © 2018 Wiley Periodicals, Inc.

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

CuZn Alloy- Based Electrocatalyst for CO2 Reduction

KAUST Repository

Alazmi, Amira

2014-06-01

ABSTRACT CuZn Alloy- Based Electrocatalyst for CO2 Reduction Amira Alazmi Carbon dioxide (CO2) is one of the major greenhouse gases and its emission is a significant threat to global economy and sustainability. Efficient CO2 conversion leads to utilization of CO2 as a carbon feedstock, but activating the most stable carbon-based molecule, CO2, is a challenging task. Electrochemical conversion of CO2 is considered to be the beneficial approach to generate carbon-containing fuels directly from CO2, especially when the electronic energy is derived from renewable energies, such as solar, wind, geo-thermal and tidal. To achieve this goal, the development of an efficient electrocatalyst for CO2 reduction is essential. In this thesis, studies on CuZn alloys with heat treatments at different temperatures have been evaluated as electrocatalysts for CO2 reduction. It was found that the catalytic activity of these electrodes was strongly dependent on the thermal oxidation temperature before their use for electrochemical measurements. The polycrystalline CuZn electrode without thermal treatment shows the Faradaic efficiency for CO formation of only 30% at applied potential ~−1.0 V vs. RHE with current density of ~−2.55 mA cm−2. In contrast, the reduction of oxide-based CuZn alloy electrode exhibits 65% Faradaic efficiency for CO at lower applied potential about −1.0 V vs. RHE with current density of −2.55 mA cm−2. Furthermore, stable activity was achieved over several hours of the reduction reaction at the modified electrodes. Based on electrokinetic studies, this improvement could be attributed to further stabilization of the CO2•− on the oxide-based Cu-Zn alloy surface.

Computational design of precipitation-strengthened titanium-nickel-based shape memory alloys

Science.gov (United States)

Bender, Matthew D.

Motivated by performance requirements of future medical stent applications, experimental research addresses the design of novel TiNi-based, superelastic shape-memory alloys employing nanoscale precipitation strengthening to minimize accommodation slip for cyclic stability and to increase output stress capability for smaller devices. Using a thermodynamic database describing the B2 and L21 phases in the Al-Ni-Ti-Zr system, Thermo-Calc software was used to assist modeling the evolution of phase composition during 600°C isothermal evolution of coherent L21 Heusler phase precipitation from supersaturated TiNi-based B2 phase matrix in an alloy experimentally characterized by atomic-scale Local Electrode Atom Probe (LEAP) microanalysis. Based on measured evolution of the alloy hardness (under conditions stable against martensitic transformation) a model for the combined effects of solid solution strengthening and precipitation strengthening was calibrated, and the optimum particle size for efficient strengthening was identified. Thermodynamic modeling of the evolution of measured phase fractions and compositions identified the interfacial capillary energy enabling thermodynamic design of alloy microstructure with the optimal strengthening particle size. Extension of alloy designs to incorporate Pt and Pd for reducing Ni content, enhancing radiopacity, and improving manufacturability were considered using measured Pt and Pd B2/L2 1 partitioning coefficients. After determining that Pt partitioning greatly increases interphase misfit, full attention was devoted to Pd alloy designs. A quantitative approach to radiopacity was employed using mass attenuation as a metric. Radiopacity improvements were also qualitatively observed using x-ray fluoroscopy. Transformation temperatures were experimentally measured as a function of Al and Pd content. Redlich-Kister polynomial modeling was utilized for the dependence of transformation reversion Af temperature on B2 matrix phase

Europium and samarium doped calcium sulfide thin films grown by PLD

International Nuclear Information System (INIS)

Christoulakis, S.; Suchea, M; Katsarakis, N.; Koudoumas, E

2007-01-01

Europium and samarium doped calcium sulfide thin films (CaS:Eu,Sm) with different thickness were prepared by the pulsed laser deposition technique using sintered targets. A typical homemade deposition chamber and XeCl excimer laser (308 nm) were employed and the films were deposited in helium atmosphere onto silicon and corning glass substrates. Structural investigations carried out by X-ray diffraction and atomic force microscopy showed a strong influence of the deposition parameters on the film properties. The films grown had an amorphous or polycrystalline structure depending on growth temperature and the number of pulses used, the same parameters affecting the film roughness, the grain shape and dimensions, the film thickness and the optical transmittance. This work indicates that pulsed laser deposition can be a suitable technique for the preparation of CaS:Eu,Sm thin films, the film characteristics being controlled by the growth conditions

Interstitial-phase precipitation in iron-base alloys: a comparative study

International Nuclear Information System (INIS)

Pelton, A.R.

1982-06-01

Recent developments have elucidated the atomistic mechanisms of precipitation of interstitial elements in simple alloy systems. However, in the more technologically important iron base alloys, interstitial phase precipitation is generally not well understood. The present experimental study was therefore designed to test the applicability of these concepts to more complex ferrous alloys. Hence, a comparative study was made of interstitial phase precipitation in ferritic Fe-Si-C and in austenitic phosphorus-containing Fe-Cr-Ni steels. These systems were subjected to a variety of quench-age thermal treatments, and the microstructural development was subsequently characterized by transmission electron microscopy

Corrosion of iron-base alloys by lithium

International Nuclear Information System (INIS)

Selle, J.E.

1976-01-01

A review of corrosion mechanisms operating in lithium-iron-base alloy systems is presented along with data obtained with thermal-convection loops of niobium-stabilized 2 1 / 4 percent Cr-1 percent Mo steel and types 304L and 321 stainless steels. A corrosion rate of 2.3 μm/year (0.09 mil/year) was obtained on the 2 1 / 4 percent Cr-1 percent Mo steel at 600 0 C. Considerably more mass transport of alloying constituents and a maximum corrosion rate of about 14 μm/year (0.55 mil/year) was obtained with the austenitic stainless steels. Results of metallography, x-ray fluorescence analysis, scanning electron microscopy, and weight-change data are presented and discussed

Magnesium-based hydrogen alloy anodes for a nickel metal hydrides secondary battery

Energy Technology Data Exchange (ETDEWEB)

Cui, N.; Luan, B.; Zhao, H.J.; Liu, H.K.; Dou, S.X. [Univ of Wollongong, Wollongong, NSW (Australia). Centre for Superconducting and Electronic Materials

1996-12-31

Extensive work has been carried out in our group to try utilizing magnesium-based hydrogen storage alloys as a low cost and high performance anode materials for Ni-MH battery. It was found that the modified Mg{sub 2}Ni alloy anodes were able to be charged-discharged effectively in a KOH aqueous solution at ambient temperature. The discharge capacity and cycle have been substantially improved in four ways: (1) by partial substitution of La, Ti, V, Zr, Ca for Mg and Fe, Co, Cu, Al, Si, Y, Mn for Ni in Mg{sub 2}Ni; (2) by composite of Mg{sub 2}Ni with another hydrogen storage alloys; (3) by room-temperature surface microencapsulation and, (4) by ultrasound treatment of alloy powders. A discharge capacity of 170 mAh/g has been obtained from the modified Mg{sub 2}Ni-type alloy electrode, and the cycle life has exceeded 350 cycles. The high rate dischargeability was also significantly improved by the modification. It was concluded that magnesium-based hydrogen storage alloys would become promising anode materials for Ni- MH secondary battery with further improvement of discharge capacity and cycling performance

Magnesium-based hydrogen alloy anodes for a nickel metal hydrides secondary battery

International Nuclear Information System (INIS)

Cui, N.; Luan, B.; Zhao, H.J.; Liu, H.K.; Dou, S.X.

1996-01-01

Extensive work has been carried out in our group to try utilizing magnesium-based hydrogen storage alloys as a low cost and high performance anode materials for Ni-MH battery. It was found that the modified Mg 2 Ni alloy anodes were able to be charged-discharged effectively in a KOH aqueous solution at ambient temperature. The discharge capacity and cycle have been substantially improved in four ways: (1) by partial substitution of La, Ti, V, Zr, Ca for Mg and Fe, Co, Cu, Al, Si, Y, Mn for Ni in Mg 2 Ni; (2) by composite of Mg 2 Ni with another hydrogen storage alloys; (3) by room-temperature surface microencapsulation and, (4) by ultrasound treatment of alloy powders. A discharge capacity of 170 mAh/g has been obtained from the modified Mg 2 Ni-type alloy electrode, and the cycle life has exceeded 350 cycles. The high rate dischargeability was also significantly improved by the modification. It was concluded that magnesium-based hydrogen storage alloys would become promising anode materials for Ni- MH secondary battery with further improvement of discharge capacity and cycling performance

Ductile Bulk Aluminum-Based Alloy with Good Glass-Forming Ability and High Strength

International Nuclear Information System (INIS)

Long-Chao, Zhuo; Shu-Jie, Pang; Hui, Wang; Tao, Zhang

2009-01-01

Based on a new approach for designing glassy alloy compositions, bulk Al-based alloys with good glass-forming ability (GFA) are synthesized. The cast Al 86 Si 0.5 Ni 4.06 Co 2.94 Y 6 Sc 0.5 rod with a diameter of 1 mm shows almost fully amorphous structure besides about 5% fcc-Al nucleated in the center of the rod. The bulk alloy with high Al concentration exhibits an ultrahigh yield strength of 1.18 GPa and maximum strength of 1.27 GPa as well as an obvious plastic strain of about 2.4% during compressive deformation. This light Al-based alloy with good GFA and mechanical properties is promising as a new high specific strength material with good deformability. (condensed matter: structure, mechanical and thermal properties)

Development of wear-resistant coatings for cobalt-base alloys

International Nuclear Information System (INIS)

Cockeram, B.V.

1999-01-01

The costs and hazards resulting from nuclear plant radiation exposure with activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant coating. However, the hardnesses of many cobalt-base wear alloys are significantly lower than conventional PVD hard coatings, and mechanical support of the hard coating is a concern. Four approaches have been taken to minimize the hardness differences between the substrate and PVD hard coating: (1) use a thin Cr-nitride hard coating with layers that are graded with respect to hardness, (2) use a thicker, multilayered coating (Cr-nitride or Zr-nitride) with graded layers, (3) use nitriding to harden the alloy subsurface followed by application of a multilayered coating of Cr-nitride, and (4) use of nitriding alone. Since little work has been done on application of PVD hard coatings to cobalt-base alloys, some details on process development and characterization of the coatings is presented. Scratch testing was used to evaluate the adhesion of the different coatings. A bench-top rolling contact test was used to evaluate the wear resistance of the coatings. The test results are discussed, and the more desirable coating approaches are identified

The prospects of biodegradable magnesium-based alloys in osteosynthesis

Directory of Open Access Journals (Sweden)

V. N. Chorny

2013-12-01

various types of implants for osteosynthesis in traumatology and orthopedics. As the analysis of scientific papers over the past decade, the number of scientific articles devoted to the study of the properties of magnesium alloys and their effect on bone formation, as well as their use in osteosynthesis has grown significantly. Implants which are based on magnesium, may have several advantages over bioinert metal alloys, polymers, and bioceramics. They are not toxic, not carcinogenic, the mechanical properties of a structure close to the cortical bone, and may have osteoinductive and anti-bacterial action. Also, there is no need for a second surgical intervention. The main problems to be addressed, in our view, are as follows. 1. Need to examine the nature of -bone formation in the fracture in the presence of the implant based on magnesium alloy. 2. To examine the impact of products of magnesium degradation on the surrounding tissue and the body as a whole. 3. Loss of rigidity of the implant magnesium based alloy in the process of biodegradation.

In vitro corrosion of dental Au-based casting alloys in polyvinylpyrrolidone-iodine solution.

Science.gov (United States)

Takasusuki, Norio; Ida, Yusuke; Hirose, Yukito; Ochi, Morio; Endo, Kazuhiko

2013-01-01

The corrosion and tarnish behaviors of two Au-based casting alloys (ISO type 1 and type 4 Au alloys) and their constituent pure metals, Au, Ag, Cu, Pt, and Pd in a polyvinylpyrrolidone-iodine solution were examined. The two Au alloys actively corroded, and the main anodic reaction for both was dissolution of Au as AuI₂(-). The amount of Au released from the ISO type 1 Au alloy was significantly larger than that from the ISO type 4 Au alloy (Palloy exhibited higher susceptibility to tarnishing than the type 4 alloy. The corrosion forms of the two Au alloys were found to be completely different, i.e., the type 1 alloy exhibited the corrosion attack over the entire exposed surface with a little irregularity whereas the type 4 alloy exhibited typical intergranular corrosion, which was caused by local cells produced by segregation of Pd and Pt.

Research into Oil-based Colloidal-Graphite Lubricants for Forging of Al-based Alloys

International Nuclear Information System (INIS)

Petrov, A.; Petrov, P.; Petrov, M.

2011-01-01

The presented paper describes the topical problem in metal forging production. It deals with the choice of an optimal lubricant for forging of Al-based alloys. Within the scope of the paper, the properties of several oil-based colloidal-graphite lubricants were investigated. The physicochemical and technological properties of these lubricants are presented. It was found that physicochemical properties of lubricant compositions have an influence on friction coefficient value and quality of forgings.The ring compression method was used to estimate the friction coefficient value. Hydraulic press was used for the test. The comparative analysis of the investigated lubricants was carried out. The forging quality was estimated on the basis of production test. The practical recommendations were given to choose an optimal oil-based colloidal-graphite lubricant for isothermal forging of Al-based alloy.

Characterization of fabricated cobalt-based alloy/nano bioactive glass composites

Energy Technology Data Exchange (ETDEWEB)

Bafandeh, Mohammad Reza, E-mail: mr.bafandeh@gmail.com [Department of Materials Science and Engineering, Faculty of Engineering, University of Kashan, Kashan (Iran, Islamic Republic of); Gharahkhani, Raziyeh; Fathi, Mohammad Hossein [Department of Materials Engineering, Isfahan University of Technology (IUT), Isfahan 84156-83111 (Iran, Islamic Republic of)

2016-12-01

In this work, cobalt-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. Scanning electron microscopy images of two- step sintered composites revealed relatively dense microstructure. The results showed that density of composite samples decreased with increase in NBG amount. The microstructure analysis as well as energy dispersive X-ray analysis (EDX) revealed that small amount of calcium phosphate phases precipitates on the surface of composite samples after 1 week immersion in SBF. After 2 weeks immersion, considerable amounts of cauliflower-like shaped precipitations were seen on the surface of the composites. Based on EDX analysis, these precipitations were composed mainly from Ca, P and Si. The observed bands in the Fourier transform infrared spectroscopy of immersed composites samples for 4 weeks in SBF, were characteristic bands of hydroxyapatite. Therefore it is possible to form hydroxyapatite layer on the surface of composite samples during immersion in SBF. The results indicated that prepared composites unlike cobalt-based alloy are bioactive, promising their possibility for implant applications. - Highlights: • Co-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared. • In order to study their bioactivity, composite samples were immersed in SBF solution for 1 to 4 weeks. • Immersion in SBF accompanied with precipitation of hydroxyapatite on surface of samples. • Prepared composite samples unlike cobalt-based alloy were bioactive.

Characterization of fabricated cobalt-based alloy/nano bioactive glass composites

International Nuclear Information System (INIS)

Bafandeh, Mohammad Reza; Gharahkhani, Raziyeh; Fathi, Mohammad Hossein

2016-01-01

In this work, cobalt-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared and their bioactivity after immersion in simulated body fluid (SBF) for 1 to 4 weeks was studied. Scanning electron microscopy images of two- step sintered composites revealed relatively dense microstructure. The results showed that density of composite samples decreased with increase in NBG amount. The microstructure analysis as well as energy dispersive X-ray analysis (EDX) revealed that small amount of calcium phosphate phases precipitates on the surface of composite samples after 1 week immersion in SBF. After 2 weeks immersion, considerable amounts of cauliflower-like shaped precipitations were seen on the surface of the composites. Based on EDX analysis, these precipitations were composed mainly from Ca, P and Si. The observed bands in the Fourier transform infrared spectroscopy of immersed composites samples for 4 weeks in SBF, were characteristic bands of hydroxyapatite. Therefore it is possible to form hydroxyapatite layer on the surface of composite samples during immersion in SBF. The results indicated that prepared composites unlike cobalt-based alloy are bioactive, promising their possibility for implant applications. - Highlights: • Co-based alloy/nano bioactive glass (NBG) composites with 10, 15 and 20 wt% NBG were prepared. • In order to study their bioactivity, composite samples were immersed in SBF solution for 1 to 4 weeks. • Immersion in SBF accompanied with precipitation of hydroxyapatite on surface of samples. • Prepared composite samples unlike cobalt-based alloy were bioactive.

Atomic-scale properties of Ni-based FCC ternary, and quaternary alloys

International Nuclear Information System (INIS)

Tamm, Artur; Aabloo, Alvo; Klintenberg, Mattias; Stocks, Malcolm; Caro, Alfredo

2015-01-01

The aim of this study is to characterize some atomic-scale properties of Ni-based FCC multicomponent alloys. For this purpose, we use Monte Carlo method combined with density functional theory calculations to study short-range order (SRO), atomic displacements, electronic density of states, and magnetic moments in equimolar ternary NiCrCo, and quaternary NiCrCoFe alloys. According to our study, the salient features for the ternary alloy are a negative SRO parameter between Ni–Cr and a positive between Cr–Cr pairs as well as a weakly magnetic state. For the quaternary alloy we predict negative SRO parameter for Ni–Cr and Ni–Fe pairs and positive for Cr–Cr and Fe–Fe pairs. Atomic displacements for both ternary and quaternary alloys are negligible. In contrast to the ternary, the quaternary alloy shows a complex magnetic structure. The electronic structure of the ternary and quaternary alloys shows differences near the Fermi energy between a random solid solution and the predicted structure with SRO. Despite that, the calculated EXAFS spectra does not show enough contrast to discriminate between random and ordered structures. The predicted SRO has an impact on point-defect energetics, electron–phonon coupling and thermodynamic functions and thus, SRO should not be neglected when studying properties of these two alloys

Bulk amorphous Mg-based alloys

DEFF Research Database (Denmark)

Pryds, Nini

2004-01-01

are discussed in this paper. On the basis of these measurements phase diagrams of the different systems were constructed. Finally, it is demonstrated that when pressing the bulk amorphous alloy onto a metallic dies at temperatures within the supercooled liquid region, the alloy faithfully replicates the surface...

Poor glass-forming ability of Fe-based alloys

DEFF Research Database (Denmark)

Zheng, H.J.; Hu, L.N.; Zhao, X.

2017-01-01

processes. By using the concept of fluid cluster and supercooled liquid fragility in metallic liquids, it has been found that this dynamic transition makes the Fe-based supercooled liquids become more unstable, which leads to the poor GFA of Fe-based alloys. Further, it has been found that the degree...

Microstructural characterisation of friction stir welding joints of mild steel to Ni-based alloy 625

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, J. [Brazilian Nanotechnology National Laboratory (LNNano), P.O. Box 6192, Campinas, SP (Brazil); University of Campinas (UNICAMP), Campinas, SP (Brazil); Ramirez, A.J., E-mail: ramirezlondono.1@osu.edu [Brazilian Nanotechnology National Laboratory (LNNano), P.O. Box 6192, Campinas, SP (Brazil); University of Campinas (UNICAMP), Campinas, SP (Brazil); Department of Materials Science and Engineering, The Ohio State University — OSU, Columbus, OH 43221 (United States)

2015-12-15

In this study, 6-mm-thick mild steel and Ni-based alloy 625 plates were friction stir welded using a tool rotational speed of 300 rpm and a travel speed of 100 mm·min{sup −1}. A microstructural characterisation of the dissimilar butt joint was performed using optical microscopy, scanning and transmission electron microscopy, and energy dispersive X-ray spectroscopy (XEDS). Six different weld zones were found. In the steel, the heat-affected zone (HAZ) was divided into three zones and was composed of ferrite, pearlite colonies with different morphologies, degenerated regions of pearlite and allotriomorphic and Widmanstätten ferrite. The stir zone (SZ) of the steel showed a coarse microstructure consisting of allotriomorphic and Widmanstätten ferrite, degenerate pearlite and MA constituents. In the Ni-based alloy 625, the thermo-mechanically affected zone (TMAZ) showed deformed grains and redistribution of precipitates. In the SZ, the high deformation and temperature produced a recrystallised microstructure, as well as fracture and redistribution of MC precipitates. The M{sub 23}C{sub 6} precipitates, present in the base material, were also redistributed in the stir zone of the Ni-based alloy. TMAZ in the steel and HAZ in the Ni-based alloy could not be identified. The main restorative mechanisms were discontinuous dynamic recrystallisation in the steel, and discontinuous and continuous dynamic recrystallisation in the Ni-based alloy. The interface region between the steel and the Ni-based alloy showed a fcc microstructure with NbC carbides and an average length of 2.0 μm. - Highlights: • Comprehensive microstructural characterisation of dissimilar joints of mild steel to Ni-based alloy • Friction stir welding of joints of mild steel to Ni-based alloy 625 produces sound welds. • The interface region showed deformed and recrystallised fcc grains with NbC carbides and a length of 2.0 μm.

Hydrogen storage in binary and ternary Mg-based alloys: A comprehensive experimental study

Energy Technology Data Exchange (ETDEWEB)

Kalisvaart, W.P.; Harrower, C.T.; Haagsma, J.; Zahiri, B.; Luber, E.J.; Ophus, C.; Mitlin, D. [Chemical and Materials Engineering, University of Alberta and National Research Council Canada, National Institute for Nanotechnology, T6G 2V4, Edmonton, Alberta (Canada); Poirier, E.; Fritzsche, H. [National Research Council Canada, SIMS, Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada)

2010-03-15

This study focused on hydrogen sorption properties of 1.5 {mu}m thick Mg-based films with Al, Fe and Ti as alloying elements. The binary alloys are used to establish as baseline case for the ternary Mg-Al-Ti, Mg-Fe-Ti and Mg-Al-Fe compositions. We show that the ternary alloys in particular display remarkable sorption behavior: at 200 C the films are capable of absorbing 4-6 wt% hydrogen in seconds, and desorbing in minutes. Furthermore, this sorption behavior is stable over cycling for the Mg-Al-Ti and Mg-Fe-Ti alloys. Even after 100 absorption/desorption cycles, no degradation in capacity or kinetics is observed. For Mg-Al-Fe, the properties are clearly worse compared to the other ternary combinations. These differences are explained by considering the properties of all the different phases present during cycling in terms of their hydrogen affinity and catalytic activity. Based on these considerations, some general design principles for Mg-based hydrogen storage alloys are suggested. (author)

Effect of Zinc Oxide Doping on Electroluminescence and Electrical Behavior of Metalloporphyrins-Doped Samarium Complex

Science.gov (United States)

Janghouri, Mohammad; Amini, Mostafa M.

2018-02-01

Samarium complex [(Sm(III)] as a new host material was used for preparation of red organic light-emitting diodes (OLEDs). Devices with configurations of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):(poly(styrenesulfonate) (PEDOT:PSS (50 nm)/polyvinyl carbazole (PVK):[zinc oxide (ZnO)] (50 nm)/[(Sm(III)]:[zinc(II) 2,3-tetrakis(dihydroxyphenyl)-porphyrin and Pt(II) 2,3-dimethoxyporphyrin] (60 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (15 nm)/Al (150 nm) have been fabricated and investigated. An electroplex occurring at the (PVK/Sm: Pt(II) 2,3-dimethoxyporphyrin) interface has been suggested when ZnO nanoparticles were doped in PVK. OLED studies have revealed that the photophysical characteristics and electrical behavior of devices with ZnO nanoparticles are much better than those of devices with pure PVK. The efficiency of devices based on [(Sm(III)] was superior than that of known aluminum tris(8-hydroxyquinoline) (Alq3) and also our earlier reports on red OLEDs under the same conditions.

Porous Nb-Ti based alloy produced from plasma spheroidized powder

Science.gov (United States)

Li, Qijun; Zhang, Lin; Wei, Dongbin; Ren, Shubin; Qu, Xuanhui

Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20-110 μm. With the decrease of particle size, a transformation from typical dendrite solidification structure to fine cell microstructure occurs. The surface of the spheroidized powder is coated by a layer of oxides consisting mainly of TiO2 and Nb2O5. Probabilities of sinter-neck formation and particle coalescence increases with increasing sintering temperature. Porous skeleton with relatively homogeneous pore distribution and open pore channel is formed after vacuum sintering at 1700 °C, and the porosity is 32%. The sintering kinetic analysis indicates that grain boundary diffusion is the primary mass transport mechanism during sintering process.

Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

Science.gov (United States)

Brady, Michael P [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN

2010-11-09

A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

Fabrication of tungsten wire reinforced nickel-base alloy composites

Science.gov (United States)

Brentnall, W. D.; Toth, I. J.

1974-01-01

Fabrication methods for tungsten fiber reinforced nickel-base superalloy composites were investigated. Three matrix alloys in pre-alloyed powder or rolled sheet form were evaluated in terms of fabricability into composite monotape and multi-ply forms. The utility of monotapes for fabricating more complex shapes was demonstrated. Preliminary 1093C (2000F) stress rupture tests indicated that efficient utilization of fiber strength was achieved in composites fabricated by diffusion bonding processes. The fabrication of thermal fatigue specimens is also described.

Lave phase precipitation in Nb- and Ti-based alloys

International Nuclear Information System (INIS)

Tewari, R.; Vishwanadh, B.; Dey, G.K.

2010-01-01

In multicomponent Nb-based alloys system, which are potential candidate materials for high temperature applications, the presence of Laves phase was noticed along with the silicides in equilibrium with the soft β-matrix. In Ti-Cr alloys, which show a tendency for inverse melting, the formation of the phase was noticed in the β matrix upon aging. The Laves phase being topologically closed pack structure appears to have strong tendency for the formation provided the criterion of atomic size factor is met

Ambient-temperature high damping capacity in TiPd-based martensitic alloys

Energy Technology Data Exchange (ETDEWEB)

Xue, Dezhen [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Zhou, Yumei, E-mail: zhouyumei@mail.xjtu.edu.cn [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ding, Xiangdong [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Otsuka, Kazuhiro [Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan); Lookman, Turab [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sun, Jun [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ren, Xiaobing [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan)

2015-04-24

Shape memory alloys (SMAs) have attracted considerable attention for their high damping capacities. Here we investigate the damping behavior of Ti{sub 50}(Pd{sub 50−x}D{sub x}) SMAs (D=Fe, Co, Mn, V) by dynamic mechanical analysis. We find that these alloys show remarkably similar damping behavior. There exists a sharp damping peak associated with the B2–B19 martensitic transformation and a high damping plateau (Q{sup −1}~0.02–0.05) over a wide ambient-temperature range (220–420 K) due to the hysteretic twin boundary motion. After doping hydrogen into the above alloys, a new relaxation-type damping peak appears in the martensite phase over 270–360 K. Such a peak is considered to originate from the interaction of hydrogen atoms with twin boundaries and the corresponding damping capacity (Q{sup −1}~0.05–0.09) is enhanced by roughly twice that of the damping plateau for each alloy. Moreover, the relaxation peaks are at higher temperatures for the TiPd-based alloys (270–370 K) than for the TiNi-based alloys (190–260 K). We discuss the influence of hydrogen diffusion, mobility of twin boundaries and hydrogen–twin boundary interaction on the temperature range of the relaxation peak. Our results suggest that a martensite, with appropriate values for twinning shear and hydrogen doping level, provides a route towards developing high damping SMAs for applications in desired temperature ranges.

Ambient-temperature high damping capacity in TiPd-based martensitic alloys

International Nuclear Information System (INIS)

Xue, Dezhen; Zhou, Yumei; Ding, Xiangdong; Otsuka, Kazuhiro; Lookman, Turab; Sun, Jun; Ren, Xiaobing

2015-01-01

Shape memory alloys (SMAs) have attracted considerable attention for their high damping capacities. Here we investigate the damping behavior of Ti 50 (Pd 50−x D x ) SMAs (D=Fe, Co, Mn, V) by dynamic mechanical analysis. We find that these alloys show remarkably similar damping behavior. There exists a sharp damping peak associated with the B2–B19 martensitic transformation and a high damping plateau (Q −1 ~0.02–0.05) over a wide ambient-temperature range (220–420 K) due to the hysteretic twin boundary motion. After doping hydrogen into the above alloys, a new relaxation-type damping peak appears in the martensite phase over 270–360 K. Such a peak is considered to originate from the interaction of hydrogen atoms with twin boundaries and the corresponding damping capacity (Q −1 ~0.05–0.09) is enhanced by roughly twice that of the damping plateau for each alloy. Moreover, the relaxation peaks are at higher temperatures for the TiPd-based alloys (270–370 K) than for the TiNi-based alloys (190–260 K). We discuss the influence of hydrogen diffusion, mobility of twin boundaries and hydrogen–twin boundary interaction on the temperature range of the relaxation peak. Our results suggest that a martensite, with appropriate values for twinning shear and hydrogen doping level, provides a route towards developing high damping SMAs for applications in desired temperature ranges

Influence of alkali metal hydroxides on corrosion of Zr-based alloys

International Nuclear Information System (INIS)

Jeong, Y.H.; Ruhmann, H.; Garzarolli, F.

1997-01-01

In this study the influence of group-1 alkali hydroxides on different zirconium based alloys has been evaluated. The experiments have been carried out in small stainless steel autoclaves at 350 deg. C in pressurized 17 MPa water, with in low (0.32 mmol), medium (4.3 mmol) and high (31.5 mmol) equimolar concentrations of Li-, Na-, K-, Rb- and Cs-Hydroxides. Two types of alloys have been investigated: Zr-Sn-(Transition metal) and Zr-Sn-Nb-(Transition metal). The corrosion behaviour was evaluated from weight gain measurements. From the experiments the cation could be identified as the responsible species for zirconium alloy corrosion in alkalized water. The radius of the cation governs the corrosion behaviour in the pre accelerated region of zircaloy corrosion. Incorporating of alkali cations into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significantly lower effect for the other bases. Nb containing alloys show lower corrosion resistance than alloys from the Zr-Sn-TRM system in all alkali solutions. Both types of alloys corrode significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behaviour in the different alkali environments and taking into account the tendency to promote accelerate corrosion, CsOH and KOH are possible alternate alkalis for PWR application. (author). 17 refs, 15 figs, 5 tabs

Influence of alkali metal hydroxides on corrosion of Zr-based alloys

Energy Technology Data Exchange (ETDEWEB)

Jeong, Y H [Korea Atomic Energy Research Inst., Dae Jun (Korea, Republic of); Ruhmann, H; Garzarolli, F [Siemens-KWU, Power Generation Group, Erlangen (Germany)

1997-02-01

In this study the influence of group-1 alkali hydroxides on different zirconium based alloys has been evaluated. The experiments have been carried out in small stainless steel autoclaves at 350 deg. C in pressurized 17 MPa water, with in low (0.32 mmol), medium (4.3 mmol) and high (31.5 mmol) equimolar concentrations of Li-, Na-, K-, Rb- and Cs-Hydroxides. Two types of alloys have been investigated: Zr-Sn-(Transition metal) and Zr-Sn-Nb-(Transition metal). The corrosion behaviour was evaluated from weight gain measurements. From the experiments the cation could be identified as the responsible species for zirconium alloy corrosion in alkalized water. The radius of the cation governs the corrosion behaviour in the pre accelerated region of zircaloy corrosion. Incorporating of alkali cations into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significantly lower effect for the other bases. Nb containing alloys show lower corrosion resistance than alloys from the Zr-Sn-TRM system in all alkali solutions. Both types of alloys corrode significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behaviour in the different alkali environments and taking into account the tendency to promote accelerate corrosion, CsOH and KOH are possible alternate alkalis for PWR application. (author). 17 refs, 15 figs, 5 tabs.

Effect of B addition to hypereutectic Ti-based alloys

International Nuclear Information System (INIS)

Louzguina-Luzgina, Larissa V.; Louzguine-Luzgin, Dmitri V.; Inoue, Akihisa

2009-01-01

The structure and mechanical properties of Ti-Fe-B and Ti-Fe-Co-B alloys produced in the shape of the arc-melted ingots of about 25 mm diameter and 10 mm height are studied. The hypereutectic alloys showed excellent compressive mechanical properties. The structures of the high-strength and ductile hypereutectic alloys studied by X-ray diffractometry and scanning electron microscopy were found to consist of the primary cubic cP2 intermetallic compound (TiFe-phase or a solid solution on its base) and a dispersed eutectic consisting of this cP2 intermetallic compound + BCC cI2 β-Ti supersaturated solid solution phase. The addition of B increased mechanical strength. Si causes embrittlement owing to the formation of alternative intermetallic compounds. The structure and deformation behaviour were studied

Long-life fatigue test results for two nickel-base structural alloys

International Nuclear Information System (INIS)

Mowbray, D.F.; Giaquinto, E.V.; Mehringer, F.J.

1978-11-01

The results are reported of fatigue tests on two nickel--base alloys, hot-cold-worked and stress-relieved nickel--chrome--iron Alloy 600 and mill-annealed nickel--chrome--moly--iron Alloy 625 in which S-N data were obtained in the life range of 10 6 to 10 10 cycles. The tests were conducted in air at 600 0 F, in the reversed membrane loading mode, at a frequency of approx. 1850 Hz. An electromagnetic, closed loop servo-controlled machine was built to perform the tests. A description of the machine is given

Investigation of phase stability of novel equiatomic FeCoNiCuZn based-high entropy alloy prepared by mechanical alloying

Science.gov (United States)

Soni, Vinay Kumar; Sanyal, S.; Sinha, S. K.

2018-05-01

The present work reports the structural and phase stability analysis of equiatomic FeCoNiCuZn High entropy alloy (HEA) systems prepared by mechanical alloying (MA) method. In this research effort some 1287 alloy combinations were extensively studied to arrive at most favourable combination. FeCoNiCuZn based alloy system was selected on the basis of physiochemical parameters such as enthalpy of mixing (ΔHmix), entropy of mixing (ΔSmix), atomic size difference (ΔX) and valence electron concentration (VEC) such that it fulfils the formation criteria of stable multi component high entropy alloy system. In this context, we have investigated the effect of novel alloying addition in view of microstructure and phase formation aspect. XRD plots of the MA samples shows the formation of stable solid solution with FCC (Face Cantered Cubic) after 20 hr of milling time and no indication of any amorphous or intermetallic phase formation. Our results are in good agreement with calculation and analysis done on the basis of physiochemical parameters during selection of constituent elements of HEA.

Advanced nickel base alloys for high strength, corrosion applications

Science.gov (United States)

Flinn, J.E.

1998-11-03

Improved nickel-base alloys of enhanced strength and corrosion resistance, produced by atomization of an alloy melt under an inert gas atmosphere and of composition 0--20Fe, 10--30Cr, 2--12Mo, 6 max. Nb, 0.05--3 V, 0.08 max. Mn, 0.5 max. Si, less than 0.01 each of Al and Ti, less than 0.05 each of P and S, 0.01--0.08C, less than 0.2N, 0.1 max. 0, bal. Ni. 3 figs.

A study of electron beam welding of Mo based TZM alloy

International Nuclear Information System (INIS)

Chakraborty, S.P.; Krishnamurthy, N.

2013-12-01

Mo based TZM alloy is one of the most promising refractory alloy having several unique high temperature properties suitable for structural applications in the new generation advanced nuclear reactors. However, this alloy easily picks up interstitial impurities such as N 2 , H 2 and C from air during welding due to its reactive nature. High melting point of TZM alloy also restricts use of conventional welding technique for welding. Hence, Electron beam welding (EBW) technique with its deep penetration power to produce narrow heat affected zones under high vacuum was employed to overcome the above welding constraints by conducting a systematic study using both processes of bead on plate and butt joint configuration. Uniform and defect free weld joints were produced. Weld joints were subjected to optical characterization, chemical homogeneity analysis and microhardness profile study across the width of welds. Improved grain structure with equiaxed grains was obtained in the weld zone as compared to fibrous base structure. Original chemical composition was retained in the weld zone. The detailed results are described in this report. (author)

Bimetallic low thermal-expansion panels of Co-base and silicide-coated Nb-base alloys for high-temperature structural applications

International Nuclear Information System (INIS)

Rhein, R.K.; Novak, M.D.; Levi, C.G.; Pollock, T.M.

2011-01-01

Research highlights: → Low net thermal expansion bimetallic structural lattice constructed. → Temperatures on the order of 1000 deg. C reached. → Improved silicide coating for niobium alloy developed. - Abstract: The fabrication and high temperature performance of low thermal expansion bimetallic lattices composed of Co-base and Nb-base alloys have been investigated. A 2D sheet lattice with a coefficient of thermal expansion (CTE) lower than the constituent materials of construction was designed for thermal cycling to 1000 deg. C with the use of elastic-plastic finite element analyses. The low CTE lattice consisted of a continuous network of the Nb-base alloy C-103 with inserts of high CTE Co-base alloy Haynes 188. A new coating approach wherein submicron alumina particles were incorporated into (Nb, Cr, Fe) silicide coatings was employed for oxidation protection of the Nb-base alloy. Thermal gravimetric analysis results indicate that the addition of submicron alumina particles reduced the oxidative mass gain by a factor of four during thermal cycling, increasing lifetime. Bimetallic cells with net expansion of 6 x 10 -6 /deg. C and 1 x 10 -6 /deg. C at 1000 deg. C were demonstrated and their measured thermal expansion characteristics were consistent with analytical models and finite element analysis predictions.

Thermogravimetric study of reduction of oxides present in oxidized nickel-base alloy powders

Science.gov (United States)

Herbell, T. P.

1976-01-01

Carbon, hydrogen, and hydrogen plus carbon reduction of three oxidized nickel-base alloy powders (a solid solution strengthened alloy both with and without the gamma prime formers aluminum and titanium and the solid solution strengthened alloy NiCrAlY) were evaluated by thermogravimetry. Hydrogen and hydrogen plus carbon were completely effective in reducing an alloy containing chromium, columbium, tantalum, molybdenum, and tungsten. However, with aluminum and titanium present the reduction was limited to a weight loss of about 81 percent. Carbon alone was not effective in reducing any of the alloys, and none of the reducing conditions were effective for use with NiCrAlY.

Alloying effect on K shell X-ray fluorescence cross-sections and yields in Ti-Ni based shape memory alloys

Directory of Open Access Journals (Sweden)

Bünyamin Alım

2018-04-01

Full Text Available K shell X-ray fluorescence cross-sections (σKα, σKβ and σK, and K shell fluorescence yields (ωK of Ti, Ni both in pure metals and in different alloy compositions (TixNi1-x; x = 0.3, 0.4, 0.5, 0.6, 0.7 were measured by using energy dispersive X-ray fluorescence (EDXRF technique. The samples were excited by 22.69 keV X-rays from a 10 mCi Cd-109 radioactive point source and K X rays emitted by samples were counted by a high resolution Si(Li solid-state detector coupled to a 4 K multichannel analyzer (MCA. The alloying effects on the X-ray fluorescence (XRF parameters of Ti-Ni shape memory alloys (SMAs were investigated. It is clearly observed that alloying effect causes to change in K shell XRF parameter values in Ti-Ni based SMAs for different compositions of x. Also, the present investigation makes it possible to perform reliable interpretation of experimental σKα, σKβ and ωK values for Ti and Ni in SMAs and can also provide quantitative information about the changes of K shell X-ray fluorescence cross sections and fluorescence yields of these metals with alloy composition. Keywords: Alloying effect, XRF, K X-ray fluorescence cross-section, K shell fluorescence yield, Shape memory alloy

Determination of trace amounts of rare earth elements in samarium, terbium and disprosium oxides by graphite furnace atomic-absorption spectrometry

International Nuclear Information System (INIS)

Dantas, E.S.K.

1990-01-01

A graphite furnace atomic-absorption spectrometry method for the determination of neodymium, europium, terbium, dysprosium and yttrium at trace level in samarium oxide; of samarium, europium, dysprosium, holmium, erbium and yttrium in terbium oxide and of europium, terbium, holmium, erbium and yttrium in dysprosium oxide was established. The best pyrolysis and atomization temperatures were determined for each lanthanide considered. Calibration curves were obtained for the pure elements, for binary mixtures formed by the matrix and each of the lanthanides studied and, finally, for the complex mixtures constituted by the matrix and all the other lanthanide of the group under scrutiny. This study has been carried out to examine the interference of the presence of one lanthanide on the behaviour of the other, since a lack of linearity on the calibration curves has been observed in some cases. Detection and determination limits have been determined as well. The detection limits encountered were within the range 0.002 to 0.3% for different elements. The precision of the method expressed as the relative standard deviation was calculated for each element present in each of the matrices studied. The conclusion arrived at is that the method can be applied for determining the above mentioned lanthanides present in the matrices studied with purity up to 99.50%. (author)

Grain Refinement of Al-Si-Fe-Cu-Zn-Mn Based Alloy by Al-Ti-B Alloy and Its Effect on Mechanical Properties.

Science.gov (United States)

Yoo, Hyo-Sang; Kim, Yong-Ho; Jung, Chang-Gi; Lee, Sang-Chan; Lee, Seong-Hee; Son, Hyeon-Taek

2018-03-01

We investigated the effects of Al-5.0wt%Ti-1.0wt%B addition on the microstructure and mechanical properties of the as-extruded Al-0.15wt%Si-0.2wt%Fe-0.3wt%Cu-0.15wt%Zn-0.9wt%Mn based alloys. The Aluminum alloy melt was held at 800 °C and then poured into a mould at 200 °C. Aluminum alloys were hot-extruded into a rod that was 12 mm in thickness with a reduction ratio of 38:1. AlTiB addition to Al-0.15Si-0.2Fe-0.3Cu-0.15Zn-0.9Mn based alloys resulted in the formation of Al3Ti and TiB2 intermetallic compounds and grain refinement. With increasing of addition AlTiB, ultimate tensile strength increased from 93.38 to 99.02 to 100.01 MPa. The tensile strength of the as-extruded alloys was improved due to the formation of intermetallic compounds and grain refinement.

FEATURES OF SPHEROIDIZING MODIFICATION OF HIGH-STRENGTH CAST IRON WITH MASTER ALLOYS BASED ON COPPER

Directory of Open Access Journals (Sweden)

A. S. Kalinichenko

2016-01-01

Full Text Available The increase of efficiency of modification process for ductile iron is topically, thereby increasing its mechanical and operational properties. For these purposes, in practice, various magnesium containing alloys are used, including «heavy» ones on the basis of Copper and Nickel. The analysis has shown that the application of bulk inoculating alloys based on copper basis were not effectively due to long dissolution period. From this point of view, the interest is high-speed casting, allowing the production of inoculating alloys in the form of strips – chips that are characterized by a low dissolution time and low piroeffekt. The aim of this work is to study the features of structure formation in nodular cast iron using different spheroidizing alloys based on copper. Studies have shown that the transition from the use of briquetted form alloys based on copper and magnesium to the «chips-inoculating alloys» allowed increasing the efficiency of the spheroidizing process. Further improvement in the quality of ductile iron can be achieved by the use in «chip-inoculating alloys» additives of nanosized yttrium oxide powder. 

Room temperature synthesis of Ni-based alloy nanoparticles by radiolysis.

Energy Technology Data Exchange (ETDEWEB)

Nenoff, Tina Maria; Berry, Donald T.; Lu, Ping; Leung, Kevin; Provencio, Paula Polyak; Stumpf, Roland Rudolph; Huang, Jian Yu; Zhang, Zhenyuan

2009-09-01

Room temperature radiolysis, density functional theory, and various nanoscale characterization methods were used to synthesize and fully describe Ni-based alloy nanoparticles (NPs) that were synthesized at room temperature. These complementary methods provide a strong basis in understanding and describing metastable phase regimes of alloy NPs whose reaction formation is determined by kinetic rather than thermodynamic reaction processes. Four series of NPs, (Ag-Ni, Pd-Ni, Co-Ni, and W-Ni) were analyzed and characterized by a variety of methods, including UV-vis, TEM/HRTEM, HAADF-STEM and EFTEM mapping. In the first focus of research, AgNi and PdNi were studied. Different ratios of Ag{sub x}- Ni{sub 1-x} alloy NPs and Pd{sub 0.5}- Ni{sub 0.5} alloy NP were prepared using a high dose rate from gamma irradiation. Images from high-angle annular dark-field (HAADF) show that the Ag-Ni NPs are not core-shell structure but are homogeneous alloys in composition. Energy filtered transmission electron microscopy (EFTEM) maps show the homogeneity of the metals in each alloy NP. Of particular interest are the normally immiscible Ag-Ni NPs. All evidence confirmed that homogeneous Ag-Ni and Pd-Ni alloy NPs presented here were successfully synthesized by high dose rate radiolytic methodology. A mechanism is provided to explain the homogeneous formation of the alloy NPs. Furthermore, studies of Pd-Ni NPs by in situ TEM (with heated stage) shows the ability to sinter these NPs at temperatures below 800 C. In the second set of work, CoNi and WNi superalloy NPs were attempted at 50/50 concentration ratios using high dose rates from gamma irradiation. Preliminary results on synthesis and characterization have been completed and are presented. As with the earlier alloy NPs, no evidence of core-shell NP formation occurs. Microscopy results seem to indicate alloying occurred with the CoNi alloys. However, there appears to be incomplete reduction of the Na{sub 2}WO{sub 4} to form the W

Ni-Cr based dental alloys; Ni release, corrosion and biological evaluation

Energy Technology Data Exchange (ETDEWEB)

Reclaru, L., E-mail: lucien.reclaru@pxgroup.com [PX Holding S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Unger, R.E.; Kirkpatrick, C.J. [Institute for Pathology, REPAIR Lab, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr.1, D-55101 Mainz (Germany); Susz, C.; Eschler, P.-Y.; Zuercher, M.-H. [PX Holding S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Antoniac, I. [Materials Science and Engineering Faculty, Politehnica of Bucharest, 060042 Bucharest (Romania); Luethy, H. [Institute of Dental Materials Science and Technology, University of Basel, Hebelstrasse 3, CH-4056 Basel (Switzerland)

2012-08-01

In the last years the dental alloy market has undergone dramatic changes for reasons of economy and biocompatibility. Nickel based alloys have become widely used substitute for the much more expensive precious metal alloys. In Europe the prevalence of nickel allergy is 10-15% for female adults and 1-3% for male adults. Despite the restrictions imposed by the EU for the protection of the general population in contact dermatitis, the use of Ni-Cr dental alloys is on the increase. Some questions have to be faced regarding the safety risk of nickel contained in dental alloys. We have collected based on many EU markets, 8 Ni-Cr dental alloys. Microstructure characterization, corrosion resistance (generalized, crevice and pitting) in saliva and the quantities of cations released in particular nickel and CrVI have been evaluated. We have applied non parametric classification tests (Kendall rank correlation) for all chemical results. Also cytotoxicity tests and an evaluation specific to TNF-alpha have been conducted. According to the obtained results, it was found that their behavior to corrosion was weak but that nickel release was high. The quantities of nickel released are higher than the limits imposed in the EU concerning contact with the skin or piercing. Surprisingly the biological tests did not show any cytotoxic effect on Hela and L929 cells or any change in TNF-alpha expression in monocytic cells. The alloys did not show any proinflammatory response in endothelial cells as demonstrated by the absence of ICAM-1 induction. We note therefore that there is really no direct relationship between the in vitro biological evaluation tests and the physico-chemical characterization of these dental alloys. Clinical and epidemiological studies are required to clarify these aspects. - Highlights: Black-Right-Pointing-Pointer Nickel released was higher than the limits imposed in EU in contact with the skin. Black-Right-Pointing-Pointer No direct relationship between the

Modification of fuel performance code to evaluate iron-based alloy behavior under LOCA scenario

Energy Technology Data Exchange (ETDEWEB)

Giovedi, Claudia; Martins, Marcelo Ramos, E-mail: claudia.giovedi@labrisco.usp.br, E-mail: mrmartin@usp.br [Laboratorio de Analise, Avaliacao e Gerenciamento de Risco (LabRisco/POLI/USP), São Paulo, SP (Brazil); Abe, Alfredo; Muniz, Rafael O.R.; Gomes, Daniel de Souza; Silva, Antonio Teixeira e, E-mail: ayabe@ipen.br, E-mail: dsgomes@ipen.br, E-mail: teixiera@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Accident tolerant fuels (ATF) has been studied since the Fukushima Daiichi accident in the research efforts to develop new materials which under accident scenarios could maintain the fuel rod integrity for a longer period compared to the cladding and fuel system usually utilized in Pressurized Water Reactors (PWR). The efforts have been focused on new materials applied as cladding, then iron-base alloys appear as a possible candidate. The aim of this paper is to implement modifications in a fuel performance code to evaluate the behavior of iron based alloys under Loss-of-Coolant Accident (LOCA) scenario. For this, initially the properties related to the thermal and mechanical behavior of iron-based alloys were obtained from the literature, appropriately adapted and introduced in the fuel performance code subroutines. The adopted approach was step by step modifications, where different versions of the code were created. The assessment of the implemented modification was carried out simulating an experiment available in the open literature (IFA-650.5) related to zirconium-based alloy fuel rods submitted to LOCA conditions. The obtained results for the iron-based alloy were compared to those obtained using the regular version of the fuel performance code for zircaloy-4. The obtained results have shown that the most important properties to be changed are those from the subroutines related to the mechanical properties of the cladding. The results obtained have shown that the burst is observed at a longer time for fuel rods with iron-based alloy, indicating the potentiality of this material to be used as cladding with ATF purposes. (author)

Modification of fuel performance code to evaluate iron-based alloy behavior under LOCA scenario

International Nuclear Information System (INIS)

Giovedi, Claudia; Martins, Marcelo Ramos; Abe, Alfredo; Muniz, Rafael O.R.; Gomes, Daniel de Souza; Silva, Antonio Teixeira e

2017-01-01

Accident tolerant fuels (ATF) has been studied since the Fukushima Daiichi accident in the research efforts to develop new materials which under accident scenarios could maintain the fuel rod integrity for a longer period compared to the cladding and fuel system usually utilized in Pressurized Water Reactors (PWR). The efforts have been focused on new materials applied as cladding, then iron-base alloys appear as a possible candidate. The aim of this paper is to implement modifications in a fuel performance code to evaluate the behavior of iron based alloys under Loss-of-Coolant Accident (LOCA) scenario. For this, initially the properties related to the thermal and mechanical behavior of iron-based alloys were obtained from the literature, appropriately adapted and introduced in the fuel performance code subroutines. The adopted approach was step by step modifications, where different versions of the code were created. The assessment of the implemented modification was carried out simulating an experiment available in the open literature (IFA-650.5) related to zirconium-based alloy fuel rods submitted to LOCA conditions. The obtained results for the iron-based alloy were compared to those obtained using the regular version of the fuel performance code for zircaloy-4. The obtained results have shown that the most important properties to be changed are those from the subroutines related to the mechanical properties of the cladding. The results obtained have shown that the burst is observed at a longer time for fuel rods with iron-based alloy, indicating the potentiality of this material to be used as cladding with ATF purposes. (author)

Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report

Energy Technology Data Exchange (ETDEWEB)

Rapp, R.A. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

1998-03-10

With the aid of computer-assisted calculations of the equilibrium vapor pressures in halide-activated cementation packs, processing conditions have been identified and experimentally verified for the codeposition of two or more alloying elements in a diffusion coating on a variety of steels and refractory metal alloys. A new comprehensive theory to treat the multi-component thermodynamic equilibria in the gas phase for several coexisting solid phases was developed and used. Many different processes to deposit various types of coatings on several types of steels were developed: Cr-Si codeposition for low- or medium-carbon steels, Cr-Al codeposition on low-carbon steels to yield either a Kanthal-type composition (Fe-25Cr-4Al in wt.%) or else a (Fe, Cr){sub 3}Al surface composition. An Fe{sub 3}Al substrate was aluminized to achieve an FeAl surface composition, and boron was also added to ductilize the coating. The developmental Cr-lean ORNL alloys with exceptional creep resistance were Cr-Al coated to achieve excellent oxidation resistance. Alloy wires of Ni-base were aluminized to provide an average composition of Ni{sub 3}Al for use as welding rods. Several different refractory metal alloys based on Cr-Cr{sub 2}Nb have been silicided, also with germanium additions, to provide excellent oxidation resistance. A couple of developmental Cr-Zr alloys were similarly coated and tested.

Self-passivating bulk tungsten-based alloys manufactured by powder metallurgy

Science.gov (United States)

López-Ruiz, P.; Ordás, N.; Lindig, S.; Koch, F.; Iturriza, I.; García-Rosales, C.

2011-12-01

Self-passivating tungsten-based alloys are expected to provide a major safety advantage compared to pure tungsten, which is at present the main candidate material for the first wall armour of future fusion reactors. WC10Si10 alloys were manufactured by mechanical alloying (MA) in a Planetary mill and subsequent hot isostatic pressing (HIP), achieving densities above 95%. Different MA conditions were studied. After MA under optimized conditions, a core with heterogeneous microstructure was found in larger powder particles, resulting in the presence of some large W grains after HIP. Nevertheless, the obtained microstructure is significantly refined compared to previous work. First MA trials were also performed on the Si-free system WCr12Ti2.5. In this case a very homogeneous structure inside the powder particles was obtained, and a majority ternary metastable bcc phase was found, indicating that almost complete alloying occurred. Therefore, a very fine and homogeneous microstructure can be expected after HIP in future work.

Self-passivating bulk tungsten-based alloys manufactured by powder metallurgy

International Nuclear Information System (INIS)

López-Ruiz, P; Ordás, N; Iturriza, I; García-Rosales, C; Lindig, S; Koch, F

2011-01-01

Self-passivating tungsten-based alloys are expected to provide a major safety advantage compared to pure tungsten, which is at present the main candidate material for the first wall armour of future fusion reactors. WC10Si10 alloys were manufactured by mechanical alloying (MA) in a Planetary mill and subsequent hot isostatic pressing (HIP), achieving densities above 95%. Different MA conditions were studied. After MA under optimized conditions, a core with heterogeneous microstructure was found in larger powder particles, resulting in the presence of some large W grains after HIP. Nevertheless, the obtained microstructure is significantly refined compared to previous work. First MA trials were also performed on the Si-free system WCr12Ti2.5. In this case a very homogeneous structure inside the powder particles was obtained, and a majority ternary metastable bcc phase was found, indicating that almost complete alloying occurred. Therefore, a very fine and homogeneous microstructure can be expected after HIP in future work.

Effects in Mg-Zn-based alloys strengthened by quasicrystalline phase

International Nuclear Information System (INIS)

Vlček, M; Čížek, J; Lukáč, F; Melikhova, O; Hruška, P; Procházka, I; Vlach, M; Stulíková, I; Smola, B; Jäger, A

2016-01-01

Magnesium Mg-based alloys are promising lightweight structural materials for automotive, aerospace and biomedical applications. Recently Mg-Zn-Y system attracted a great attention due to a stable icosahedral phase (I-phase) with quasicrystalline structure which is formed in these alloys. Positron lifetime spectroscopy and in situ synchrotron X-ray diffraction were used to study thermal stability of I-phase and precipitation effects in Mg-Zn-Y and Mg- Zn-Al alloys. All alloys containing quasicrystalline I-phase exhibit misfit defects characterized by positron lifetime of ∼ 300 ps. These defects are associated with the interfaces between I- phase particles and Mg matrix. The quasicrystalline I-phase particles were found to be stable up to temperatures as high as ∼ 370°C. The W-phase is more stable and melts at ∼ 420°C. Concentration of defects associated with I-phase decreases after annealing at temperatures above ∼ 300°C. (paper)

Investigations of carbon diffusion and carbide formation in nickel-based alloys

International Nuclear Information System (INIS)

Schulten, R.; Bongartz, K.; Quadakkers, W.J.; Schuster, H.; Nickel, H.

1989-11-01

The present thesis describes the carburization behaviour of nickel based alloys in heavily carburizing environments. The mechanisms of carbon diffusion and carbide precipitation in NiCr alloys with and without ternary additions of iron, cobalt or molybdenum have been investigated. Using the results of carburization experiments, a mathematical model which describes carbon diffusion and carbide formation, was developed. The simulation of the carburization process was carried out by an iterative calculation of the local thermodynamic equilibrium in the alloy. An accurate description of the carbon profiles as a function of time became possible by using a finite-difference calculation. (orig.) [de

Effect of Alloy 625 Buffer Layer on Hardfacing of Modified 9Cr-1Mo Steel Using Nickel Base Hardfacing Alloy

Science.gov (United States)

Chakraborty, Gopa; Das, C. R.; Albert, S. K.; Bhaduri, A. K.; Murugesan, S.; Dasgupta, Arup

2016-04-01

Dashpot piston, made up of modified 9Cr-1Mo steel, is a part of diverse safety rod used for safe shutdown of a nuclear reactor. This component was hardfaced using nickel base AWS ER NiCr-B alloy and extensive cracking was experienced during direct deposition of this alloy on dashpot piston. Cracking reduced considerably and the component was successfully hardfaced by application of Inconel 625 as buffer layer prior to hardface deposition. Hence, a separate study was undertaken to investigate the role of buffer layer in reducing the cracking and on the microstructure of the hardfaced deposit. Results indicate that in the direct deposition of hardfacing alloy on modified 9Cr-1Mo steel, both heat-affected zone (HAZ) formed and the deposit layer are hard making the thickness of the hard layer formed equal to combined thickness of both HAZ and deposit. This hard layer is unable to absorb thermal stresses resulting in the cracking of the deposit. By providing a buffer layer of Alloy 625 followed by a post-weld heat treatment, HAZ formed in the modified 9Cr-1Mo steel is effectively tempered, and HAZ formed during the subsequent deposition of the hardfacing alloy over the Alloy 625 buffer layer is almost completely confined to Alloy 625, which does not harden. This reduces the cracking susceptibility of the deposit. Further, unlike in the case of direct deposition on modified 9Cr-1Mo steel, dilution of the deposit by Ni-base buffer layer does not alter the hardness of the deposit and desired hardness on the deposit surface could be achieved even with lower thickness of the deposit. This gives an option for reducing the recommended thickness of the deposit, which can also reduce the risk of cracking.

Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy.

Science.gov (United States)

Dang, B; Zhang, X; Chen, Y Z; Chen, C X; Wang, H T; Liu, F

2016-08-09

Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy.

Corrosion resistance improvement of titanium base alloys

Directory of Open Access Journals (Sweden)

Mihai V. Popa

2010-01-01

Full Text Available The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy.

Ultrahigh temperature intermetallic alloys

Energy Technology Data Exchange (ETDEWEB)

Brady, M.P.; Zhu, J.H.; Liu, C.T.; Tortorelli, P.F.; Wright, J.L.; Carmichael, C.A.; Walker, L.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1997-12-01

A new family of Cr-Cr{sub 2}X based alloys with fabricability, mechanical properties, and oxidation resistance superior to previously developed Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys has been identified. The new alloys can be arc-melted/cast without cracking, and exhibit excellent room temperature and high-temperature tensile strengths. Preliminary evaluation of oxidation behavior at 1100 C in air indicates that the new Cr-Cr{sub 2}X based alloys form an adherent chromia-based scale. Under similar conditions, Cr-Cr{sub 2}Nb and Cr-Cr{sub 2}Zr based alloys suffer from extensive scale spallation.

Magnesium secondary alloys: Alloy design for magnesium alloys with improved tolerance limits against impurities

Energy Technology Data Exchange (ETDEWEB)

Blawert, C., E-mail: carsten.blawert@gkss.d [GKSS Forschungszentrum Geesthacht GmbH, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Fechner, D.; Hoeche, D.; Heitmann, V.; Dietzel, W.; Kainer, K.U. [GKSS Forschungszentrum Geesthacht GmbH, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Zivanovic, P.; Scharf, C.; Ditze, A.; Groebner, J.; Schmid-Fetzer, R. [TU Clausthal, Institut fuer Metallurgie, Robert-Koch-Str. 42, 38678 Clausthal-Zellerfeld (Germany)

2010-07-15

The development of secondary magnesium alloys requires a completely different concept compared with standard alloys which obtain their corrosion resistance by reducing the levels of impurities below certain alloy and process depending limits. The present approach suitable for Mg-Al based cast and wrought alloys uses a new concept replacing the {beta}-phase by {tau}-phase, which is able to incorporate more impurities while being electro-chemically less detrimental to the matrix. The overall experimental effort correlating composition, microstructure and corrosion resistance was reduced by using thermodynamic calculations to optimise the alloy composition. The outcome is a new, more impurity tolerant alloy class with a composition between the standard AZ and ZC systems having sufficient ductility and corrosion properties comparable to the high purity standard alloys.

Failure probability analyses for PWSCC in Ni-based alloy welds

International Nuclear Information System (INIS)

Udagawa, Makoto; Katsuyama, Jinya; Onizawa, Kunio; Li, Yinsheng

2015-01-01

A number of cracks due to primary water stress corrosion cracking (PWSCC) in pressurized water reactors and Ni-based alloy stress corrosion cracking (NiSCC) in boiling water reactors have been detected around Ni-based alloy welds. The causes of crack initiation and growth due to stress corrosion cracking include weld residual stress, operating stress, the materials, and the environment. We have developed the analysis code PASCAL-NP for calculating the failure probability and assessment of the structural integrity of cracked components on the basis of probabilistic fracture mechanics (PFM) considering PWSCC and NiSCC. This PFM analysis code has functions for calculating the incubation time of PWSCC and NiSCC crack initiation, evaluation of crack growth behavior considering certain crack location and orientation patterns, and evaluation of failure behavior near Ni-based alloy welds due to PWSCC and NiSCC in a probabilistic manner. Herein, actual plants affected by PWSCC have been analyzed using PASCAL-NP. Failure probabilities calculated by PASCAL-NP are in reasonable agreement with the detection data. Furthermore, useful knowledge related to leakage due to PWSCC was obtained through parametric studies using this code

Local atomic order in nanocrystalline Fe-based alloys obtained by mechanical alloying

International Nuclear Information System (INIS)

Jartych, E.

2003-01-01

Using the 57 Fe Moessbauer spectroscopy, a local atomic order in nanocrystalline alloys of iron with Al, Ni, W and Mo has been determined. Alloys were prepared by mechanical alloying method. Analysis of Moessbauer spectra was performed on the basis of the local environment model in terms of Warren-Cowley parameters. It was shown that impurity atoms are not randomly distributed in the volume of the first and the second co-ordination spheres of 57 Fe nuclei and they form clusters

Mechanical properties of molybdenum alloyed liquid phase-sintered tungsten-based composites

International Nuclear Information System (INIS)

Kemp, P.B.; German, R.M.

1995-01-01

Tungsten-based composites are fabricated from mixed elemental powders using liquid phase sintering, usually with a nickel-iron matrix. During sintering, the tungsten undergoes grain growth, leading to microstructure coarsening that lowers strength but increases ductility. Often the desire is to increase strength at the sacrifice of ductility, and historically, this has been performed by postsintering deformation. There has been considerable research on alloying to adjust the as-sintered mechanical properties to match those of swaged alloys. Prior reports cover many additions, seemingly including much of the periodic table. Unfortunately, many of the modified alloys proved disappointing, largely due to degraded strength at the tungsten-matrix interface. Of these modified alloys, the molybdenum-containing systems exhibit a promising combination of properties, cost, and processing ease. For example, the 82W-8Mo-7Ni-3Fe alloy gives a yield strength that is 34% higher than the equivalent 90W-7Ni-3Fe alloy (from 535 to 715 MPa) but with a 33% decrease in fracture elongation (from 30 to 20% elongation). This article reports on experiments geared to promoting improved properties in the W-Mo-Ni-Fe alloys. However, unlike the prior research which maintained a constant Ni + Fe content and varied the W:Mo ratio, this study considers the Mo:(Ni + Fe) ratio effect for 82, 90, and 93 wt pct W

Characterization of the microstructure in Mg based alloy

KAUST Repository

Kutbee, Arwa T

2013-01-01

hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT

Resistivity and Passivity Characterization of Ni-Base Glassy Alloys in NaOH Media

Directory of Open Access Journals (Sweden)

Khadijah M. Emran

2018-01-01

Full Text Available Resistivity and passivation behavior of two Ni-base bulk metallic glasses, with the nominal composition of Ni70Cr21Si0.5B0.5P8C ≤ 0.1Co ≤ 1Fe ≤ 1 (VZ1 and Ni72.65Cr7.3-Si6.7B2.15C ≤ 0.06Fe8.2Mo3 (VZ2, in various concentrations of NaOH solutions were studied. The investigations involved cyclic polarization (CP, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM methods. Cyclic polarization measurements showed spontaneous passivation for both Ni-base glassy alloys at all alkaline concentrations, due to the presence of chromium as an alloying element that formed an oxide film on the alloy surface. The EIS analysis showed that the passive layers grown on the two Ni-base glassy alloy surfaces are formed by a double oxide layer structure. Scanning electron microscope (SEM examinations of the electrode surface showed Cr, Ni, Fe, and O rich corrosion products that reduced the extent of corrosion damage. Atomic force microscopy (AFM imaging technique was used to evaluate the topographic and morphologic features of surface layers formed on the surface of the alloys.

Crevice corrosion propagation on alloy 625 and alloy C276 in natural seawater

International Nuclear Information System (INIS)

McCafferty, E.; Bogar, F.D.; Thomas, E.D. II; Creegan, C.A.; Lucas, K.E.; Kaznoff, A.I.

1997-01-01

Chemical composition of the aqueous solution within crevices on two different Ni-Cr-Mo-Fe alloys immersed in natural seawater was determined using a semiquantitative thin-layer chromatographic method. Active crevices were found to contain concentrated amounts of dissolved Ni 2+ , Cr 3+ , Mo 3+ , and Fe 2+ ions. Propagation of crevice corrosion for the two alloys was determined from anodic polarization curves in model crevice solutions based upon stoichiometric dissolution or selective dissolution of alloy components. Both alloys 625 (UNS N06625) and C276 (UNS N10276) underwent crevice corrosion in the model crevice electrolytes. For the model crevice solution based upon selective dissolution of alloy constituents, the anodic dissolution rate for alloy 625 was higher than that for alloy C276. This trend was reversed for the model crevice solution based upon uniform dissolution of alloy constituents

Hydrogen embrittlement considerations in niobium-base alloys for application in the ITER divertor

International Nuclear Information System (INIS)

Peterson, D.T.; Hull, A.B.; Loomis, B.A.

1991-01-01

The ITER divertor will be subjected to hydrogen from aqueous corrosion by the coolant and by transfer from the plasma. Global hydrogen concentrations are one factor in assessing hydrogen embrittlement but local concentrations affected by source fluxes and thermotransport in thermal gradients are more important considerations. Global hydrogen concentrations is some corrosion- tested alloys will be presented and interpreted. The degradation of mechanical properties of Nb-base alloys due to hydrogen is a complex function of temperature, hydrogen concentration, stresses and alloy composition. The known tendencies for embrittlement and hydride formation in Nb alloys are reviewed

Vanadium-based alloy hydrides for heat pumps, compressors, and isotope separation

International Nuclear Information System (INIS)

Libowitz, G.G.

1988-01-01

A series of body-centered cubic (b.c.c.) solid solution alloys have been developed which appears to be unusually suitable for several applications involving metal hydrides. It is normally very difficult to induce the body-centered cubic metals, Nb, V, and Ta, to react with hydrogen; in bulk form the reaction will simply not occur at room temperature. Alloys containing Nb exhibited very large hysteresis effects on hydride formation and thus are not suitable for most applications. However, the V-Ti based alloys showed relatively little hysteresis, and because of their unusual thermodynamic properties offer significant advantages for the specific applications discussed below. (orig./HB)

A Study on Development of High Strength Al-Zn Based alloy for Die Casting Ⅲ

Energy Technology Data Exchange (ETDEWEB)

Shin, Sang-Soo; Park, Ik-Min [Pusan National University, Busan (Korea, Republic of); Yeom, Gil-Young; Lim, Kyoung-Mook [Korea Institute of Industrial Technology, Incheon (Korea, Republic of); Son, Hyun-Jin [Oh-Sung Co. Ltd., Siheung (Korea, Republic of)

2015-09-15

In this study, the microstructural evolution and various characteristics of Al-20⁓45wt%Zn alloys were investigated. In terms of microstructure, as the amount of Zn addition to the alloys increased, the α-phase size decreased and the α+η non-equilibrium solidification phase fraction increased. Also, increasing Zn content improved the wear resistance of the alloys, but reduced the damping capacity and toughness of the alloys. Their physical properties of the Al-Zn alloy with high Zn content, specifically the wear resistance and toughness, were superior to those of commercial ALDC12 alloys for die-casting. Based on these results, we considered the possibility of application of the developed Al-Zn alloy as a structural material.

A Study on Development of High Strength Al-Zn Based alloy for Die Casting Ⅲ

International Nuclear Information System (INIS)

Shin, Sang-Soo; Park, Ik-Min; Yeom, Gil-Young; Lim, Kyoung-Mook; Son, Hyun-Jin

2015-01-01

In this study, the microstructural evolution and various characteristics of Al-20⁓45wt%Zn alloys were investigated. In terms of microstructure, as the amount of Zn addition to the alloys increased, the α-phase size decreased and the α+η non-equilibrium solidification phase fraction increased. Also, increasing Zn content improved the wear resistance of the alloys, but reduced the damping capacity and toughness of the alloys. Their physical properties of the Al-Zn alloy with high Zn content, specifically the wear resistance and toughness, were superior to those of commercial ALDC12 alloys for die-casting. Based on these results, we considered the possibility of application of the developed Al-Zn alloy as a structural material.

Corrosion mechanism of a Ni-based alloy in supercritical water: Impact of surface plastic deformation

International Nuclear Information System (INIS)

Payet, Mickaël; Marchetti, Loïc; Tabarant, Michel; Chevalier, Jean-Pierre

2015-01-01

Highlights: • The dissolution of Ni and Fe cations occurs during corrosion of Ni-based alloys in SCW. • The nature of the oxide layer depends locally on the alloy microstructure. • The corrosion mechanism changes when cold-work increases leading to internal oxidation. - Abstract: Ni–Fe–Cr alloys are expected to be a candidate material for the generation IV nuclear reactors that use supercritical water at temperatures up to 600 °C and pressures of 25 MPa. The corrosion resistance of Alloy 690 in these extreme conditions was studied considering the surface finish of the alloy. The oxide scale could suffer from dissolution or from internal oxidation. The presence of a work-hardened zone reveals the competition between the selective oxidation of chromium with respect to the oxidation of nickel and iron. Finally, corrosion mechanisms for Ni based alloys are proposed considering the effects of plastically deformed surfaces and the dissolution.

Combinatorial thin film materials science: From alloy discovery and optimization to alloy design

Energy Technology Data Exchange (ETDEWEB)

Gebhardt, Thomas, E-mail: gebhardt@mch.rwth-aachen.de; Music, Denis; Takahashi, Tetsuya; Schneider, Jochen M.

2012-06-30

This paper provides an overview of modern alloy development, from discovery and optimization towards alloy design, based on combinatorial thin film materials science. The combinatorial approach, combining combinatorial materials synthesis of thin film composition-spreads with high-throughput property characterization has proven to be a powerful tool to delineate composition-structure-property relationships, and hence to efficiently identify composition windows with enhanced properties. Furthermore, and most importantly for alloy design, theoretical models and hypotheses can be critically appraised. Examples for alloy discovery, optimization, and alloy design of functional as well as structural materials are presented. Using Fe-Mn based alloys as an example, we show that the combination of modern electronic-structure calculations with the highly efficient combinatorial thin film composition-spread method constitutes an effective tool for knowledge-based alloy design.

Combinatorial thin film materials science: From alloy discovery and optimization to alloy design

International Nuclear Information System (INIS)

Gebhardt, Thomas; Music, Denis; Takahashi, Tetsuya; Schneider, Jochen M.

2012-01-01

This paper provides an overview of modern alloy development, from discovery and optimization towards alloy design, based on combinatorial thin film materials science. The combinatorial approach, combining combinatorial materials synthesis of thin film composition-spreads with high-throughput property characterization has proven to be a powerful tool to delineate composition–structure–property relationships, and hence to efficiently identify composition windows with enhanced properties. Furthermore, and most importantly for alloy design, theoretical models and hypotheses can be critically appraised. Examples for alloy discovery, optimization, and alloy design of functional as well as structural materials are presented. Using Fe-Mn based alloys as an example, we show that the combination of modern electronic-structure calculations with the highly efficient combinatorial thin film composition-spread method constitutes an effective tool for knowledge-based alloy design.

Damage structures in fission-neutron irradiated Ni-based alloys at high temperatures

Science.gov (United States)

Yamakawa, K.; Shimomura, Y.

1999-01-01

The defects formed in Ni based (Ni-Si, Ni-Cu and Ni-Fe) alloys which were irradiated with fission-neutrons were examined by electron microscopy. Irradiations were carried out at 473 K and 573 K. In the 473 K irradiated specimens, a high density of large interstitial loops and small vacancy clusters with stacking fault tetrahedra (SFT) were observed. The number densities of these two types of defects did not strongly depend on the amount of solute atoms in each alloy. The density of the loops in Ni-Si alloys was much higher than those in Ni-Cu and Ni-Fe alloys, while the density of SFT only slightly depended on the kind of solute. Also, the size of the loops depended on the kinds and amounts of solute. In 573 K irradiated Ni-Cu specimens, a high density of dislocation lines developed during the growth of interstitial loops. In Ni-Si alloys, the number density and size of the interstitial loops changed as a function of the amount of solute. Voids were formed in Ni-Cu alloys but scarcely formed in Ni-Si alloys. The number density of voids was one hundredth of that of SFT observed in 473 K irradiated Ni-Cu alloys. Possible formation processes of interstitial loops, SFT dislocation lines and voids are discussed.

Damage structures in fission-neutron irradiated Ni-based alloys at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yamakawa, K.; Shimomura, Y. [Hiroshima Univ. (Japan). Faculty of Engineering

1999-01-01

The defects formed in Ni based (Ni-Si, Ni-Cu and Ni-Fe) alloys which were irradiated with fission-neutrons were examined by electron microscopy. Irradiations were carried out at 473 K and 573 K. In the 473 K irradiated specimens, a high density of large interstitial loops and small vacancy clusters with stacking fault tetrahedra (SFT) were observed. The number densities of these two types of defects did not strongly depend on the amount of solute atoms in each alloy. The density of the loops in Ni-Si alloys was much higher than those in Ni-Cu and Ni-Fe alloys, while the density of SFT only slightly depended on the kind of solute. Also, the size of the loops depended on the kinds and amounts of solute. In 573 K irradiated Ni-Cu specimens, a high density of dislocation lines developed during the growth of interstitial loops. In Ni-Si alloys, the number density and size of the interstitial loops changed as a function of the amount of solute. Voids were formed in Ni-Cu alloys but scarcely formed in Ni-Si alloys. The number density of voids was one hundredth of that of SFT observed in 473 K irradiated Ni-Cu alloys. Possible formation processes of interstitial loops, SFT, dislocation lines and voids are discussed. (orig.) 8 refs.

Fluorometric determination of samarium and europium in rare earth minerals with. beta. -diketoneternary complex

Energy Technology Data Exchange (ETDEWEB)

Huang, H; Hiraki, K; Nishikawa, Y [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology

1981-07-01

This communication reported the optimum conditions for the fluorometric determination of these ions, and the method was adopted in the simultaneous determination of samarium and europium in xenotime and monazite minerals. From the experimental results on the effect of diverse ions and the extraction pH of the aqueous phase, it became clear that TTA-TOPO hexane method was the best system for the determination of samarium and europium because of the highest fluorescence sensitivity of the ternary complex, and also because the lower extraction pH eliminated the effect of diverse ions. Moreover, the very high detection limit (2 ppb) of Sm was achieved by the use of a red sensitive photomultiplier. Which was used at 644 nm, and that of Eu (0.02 ppb) at 614 nm. The procedure was established as follows: The rare earth minerals (xenotime, monazite) sample was treated with hot conc. H/sub 2/SO/sub 4/ and twice precipitated with 0.5 mol dm/sup -3/ oxalic acid (pH was adjusted to 2.0 -- 2.2). Then the precipitate was filtered and ignited to give the rare earth oxide. Fifty milligrams of the oxide was dissolved in HCl and diluted with water in order to obtain the solution containing 5 ..mu..g cm/sup -3/ rare earth oxide. An aliquot of the solution ((1.0 -- 3.0) cm/sup 3/) was adjusted to pH 5.5 with sodium acetate and shaken with 1 x 10/sup -4/ mol dm/sup -3/ TTA- 2 x 10/sup -2/ mol dm/sup -3/ TOPO hexane solution. Then the fluorescence intensity of the organic layer was measured at 644 nm for Sm and 614 nm for Eu. In this procedure, the recovery of Sm and Eu was found to be about 96%. Xenotime contained 0.70% of Sm and 0.004% of Eu, and monazite contained 1.84% of Sm and 0.003% of Eu.

Effects of metallurgical factors on stress corrosion cracking of Ni-base alloys in high temperature water

International Nuclear Information System (INIS)

Yonezawa, T.; Sasaguri, N.; Onimura, K.

1988-01-01

Nickel-base Alloy 600 is the principal material used for the steam generator tubes of PWRs. Generally, this alloy has been proven to be satisfactory for this application, however when it is subjected to extremely high stress level in PWR primary water, it may suffer from stress corrosion cracking. The authors have systematically studied the effects of test temperature and such metallurgical factors as cold working, chemical composition and heat treatment on the stress corrosion cracking of Alloy 600 in high temperature water, and also on that of Alloy 690 which is a promising material for the tubes and may provide improved crrosion resistance for steam generators. The test materials, the stress corrosion cracking test and the test results are reported. When the test temperature was raise, the stress corrosion cracking of the nickel-base alloys was accelerated. The time of stress corrosion cracking occurrence decreased with increasing applied stress, and it occurred at the stress level higher than the 0.2 % offset proof stress of Alloy 600. In Alloy 690, stress corrosion cracking was not observed at such stress level. Cold worked Alloy 600 showed higher resistance to stress corrosion cracking than the annealed alloy. (Kako, I.)

Using the PSCPCSP computer software for optimization of the composition of industrial alloys and development of new high-temperature nickel-base alloys

Science.gov (United States)

Rtishchev, V. V.

1995-11-01

Using computer programs some foreign firms have developed new deformable and castable high-temperature nickel-base alloys such as IN, Rene, Mar-M, Udimet, TRW, TM, TMS, TUT, with equiaxial, columnar, and single-crystal structures for manufacturing functional and nozzle blades and other parts of the hot duct of transport and stationary gas-turbine installations (GTI). Similar investigations have been carried out in Russia. This paper presents examples of the use of the PSCPCSP computer software for a quantitative analysis of structural und phase characteristics and properties of industrial alloys with change (within the grade range) in the concentrations of the alloying elements for optimizing the composition of the alloys and regimes of their heat treatment.

Influence of aluminium content on the physical, mechanical and sliding wear properties of zinc-based alloys

International Nuclear Information System (INIS)

Prasad, B.K.; Patwardhan, A.K.; Yegneswaran, A.H.

1997-01-01

Attention has been focussed on the influence of Al content on the physical, mechanical and sliding wear properties of Zn-based alloys. Aspects studied include microstructure, density, electrical conductivity, hardness, tensile strength and elongation as well as sliding wear response of the alloys. Microstructural features of the alloys showed the presence of primary α, eutectic/eutectoid α + η (depending on whether the alloy was hypereutectic/hypereutectoid with regard to the concentration of Al) along with the meta stable ε phase. The study suggests that it is possible to design and develop Zn-based alloys with a wide range of concentration of Al. The alloys in turn attain different combinations of physical, mechanical and wear properties which could suit a variety of engineering applications. Increasing the Al content in the alloy system proves beneficial within limits. In other words, there exists an optimum quantity of Al which could reap its advantage to the maximum extent. This of course varies with reference to a specific property of the alloy(s). The changing response of the alloys has been explained in terms of their microstructural features and the effects produced as a result of the test conditions maintained while characterizing the specimens. (orig.)

Aqueous electrochemistry of precipitation-hardened nickel base alloys

International Nuclear Information System (INIS)

Hosoya, K.; Ballinger, R.; Prybylowski, J.; Hwang, I.S.

1990-11-01

An investigation has been conducted to explore the importance of local crack tip electrochemical processes in precipitation-hardened Ni-Cr-Fe alloys driven by galvanic couples between grain boundary precipitates and the local matrix. The electrochemical behavior of γ' [Ni 3 (Al,Ti)] has been determined as a function of titanium concentration, temperature, and solution pH. The electrochemical behavior of Ni-Cr-Fe solid solution alloys has been investigated as a function of chromium content for a series of 10 Fe-variable Cr (6--18%)-balance Ni alloys, temperature, and pH. The investigation was conducted in neutral and pH3 solutions over the temperature range 25--300 degree C. The results of the investigation show that the electrochemical behavior of these systems is a strong function of temperature and composition. This is especially true for the γ' [Ni 3 (Al,Ti)] system where a transition from active/passive behavior to purely active behavior and back again occurs over a narrow temperature range near 100 degree C. Behavior of this system was also found to be a strong function of titanium concentration. In all cases, the Ni 3 (Al,Ti) phase was active with respect to the matrix. The peak in activity near 100 degree C correlates well with accelerated crack growth in this temperature range, observed in nickel-base alloy X-750 heat treated to precipitate γ' on the grain boundaries. 20 refs., 23 figs., 3 tabs

Study of magnetic hardening in Sm(Co/sub 1-x/Cu/sub x/)/sub 5/ alloy

International Nuclear Information System (INIS)

Awan, M.S.; Bhatti, A.S.; Farooque, M.

2008-01-01

Magnetic hardening has been examined in the samarium (Sm), cobalt (Co) and copper (Cu) fused permanent magnets by correlating the magnetic properties with annealing temperature and microstructure of the samples. For the Sm(Co/sub 1-x/Cu/sub x/)/sub 5/ system, with various copper contents (x=0, 0.2, 0.3, 0.4 and 0.5) the shape of initial magnetization curve indicated that the magnetic hardening process involved in these types of magnets consists of domain wall pinning type. This is consistent with the microstructure studies which show the existence of nonmagnetic Cu-rich precipitates in the Co-rich matrix. Copper substituted samples were annealed in the temperature range (300 -1000) degree C for 3h under the protective atmosphere of argon (Ar) gas. Both cast and annealed samples prepared by tri-arc melting technique exhibit two-phase microstructure responsible for enhanced magnetic properties. Metallographic and surface studies were carried out using a digital optical microscope (OM). X-ray diffraction (XRD) studies confirmed that the alloys solidefied in the hexagonal crystal structure. The lattice parameters and unit cell volume increase with increasing Cu content. Scanning electron microscope (SEM) coupled with energy dispersive X-ray (EDX) was used to examine the surface morphology, compositional variations, elemental segregations, formation and effect of annealing on the different phases. Later these parameters were related to the magnetic properties. Copper-rich phase precipitates in the Co- rich matrix may serves as the pinning centers for the domain wall motion. Introduction of these pinning centers improved the magnetic hardening of the alloy. Annealing the Cu-substituted alloy further improved the magnetic properties. During annealing, diffusion of copper played the key role for enhanced magnetic properties. It was found that both Cu substitution and subsequent annealing are the dominating factors determining the magnetic properties of these magnetic

Oxide characterization and hydrogen behaviors of Zr-based alloys

International Nuclear Information System (INIS)

Kim, Y. S.; Kim, D. J.; Kwon, S. H.; Lee, H. S.; Oh, S. J.; Yim, B. J.; Son, S. B.; Yun, S. P.

2006-03-01

The work scope and contents of the research are as follows : basic properties of zirconium alloys, hydrogen pick-up mechanism of zirconium alloy, effects of hydride on the corrosion behaviors of zirconium alloys, estimation on stress of oxide layer in the zirconium alloy, microstructure and characteristic of oxide in pre-hydrided zirconium alloys

Aluminium base amorphous and crystalline alloys with Fe impurity

International Nuclear Information System (INIS)

Sitek, J.; Degmova, J.

2006-01-01

Aluminium base alloys show remarkable mechanical properties, however their low thermal stability still limits the technological applications. Further improvement of mechanical properties can be reached by partial crystallization of amorphous alloys, which gives rise to nanostructured composites. Our work was focused on aluminium based alloys with Fe, Nb and V additions. Samples of nominal composition Al 90 Fe 7 Nb 3 and Al 94 Fe 2 V 4 were studied in amorphous state and after annealing up to 873 K. From Moessbauer spectra taken on the samples in amorphous state the value of f-factor was determined as well as corresponding Debye temperatures were calculated. Annealing at higher temperatures induced nano and microcrystalline crystallization. Moessbauer spectra of samples annealed up to 573 K are fitted only by distribution of quadrupole doublets corresponding to the amorphous state. An increase of annealing temperature leads to the structural transformation, which consists in growth of nanometer sized aluminium nuclei. This is partly reflected in Moessbauer parameters. After annealing at 673 K intermetallic phase Al 3 Fe and other Al-Fe phases are created. In this case Moessbauer spectra are fitted by quadrupole doublets. During annealing up to 873 K large grains of Fe-Al phases are created. (authors)

Memory effect of calcined layered samarium hydroxy chlorides in aqueous solution

International Nuclear Information System (INIS)

Lee, Byung Il; Byeon, Song Ho

2015-01-01

The decomposition and recovery behavior of layered samarium hydroxychloride (Sm 2 (OH) 5 Cl·nH 2 O, LSmH) has been closely studied in various conditions. Although the heat treatment of LSmH at 700 °C completely collapsed typical layered structure, the calcined LSmH (c-LSmH) recovered its layered characteristics and consequently its ability to intercalate anions into the interlayer space when it was rehydroxylated and rehydrated in aqueous solutions containing organic and inorganic anions. This phenomenon is similar to the memory effect observed in classical layered double hydroxides (LDHs), where LDHs calcined to a mixture of metal oxides can recover their layered structures in aqueous solutions. In contrast, the recovery reaction of c-LSmH in water without any counter anions was unsuccessful and instead resulted in the formation of Sm(OH) 3 . Such a difference was interpreted on the basis of the salt effect on Sm 2 (OH) 5 Cl·nH 2 O–Sm(OH) 3 phase equilibria in water

Grain refinement of permanent mold cast copper base alloys. Final report

Energy Technology Data Exchange (ETDEWEB)

Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

2004-04-29

control tool was proved in two foundries. The method can also correctly predict the onset of fading. The corrosion resistance of the grain refined alloys was measured in two solutions having different hydrogen activities, pH 6 and pH8, and compared with the base alloys. Potentiodynamic polarization and long term weight loss experiments were conducted to evaluate the corrosion resistance. Cu-Zn alloys were evaluated for dezincification. In general, the grain refined alloys performed marginally better than the base alloys.

Study of oxidation behaviour of Zr-based bulk amorphous alloy Zr 65 ...

Indian Academy of Sciences (India)

The oxidation behaviour of Zr-based bulk amorphous alloy Zr65Cu17.5Ni10Al7.5 has been studied in air environment at various temperatures in the temperature range 591–684 K using a thermogravimetric analyser (TGA). The oxidation kinetics of the alloy in the amorphous phase obeys the parabolic rate law for oxidation ...

On the nature of the variation of martensitic transformation hysteresis and SME characteristics in Fe-Ni-base alloys

International Nuclear Information System (INIS)

Koval, Yu.N.; Monastyrsky, G.E.

1995-01-01

The purpose of this paper is to summarize the various investigations, both by the authors and other works, concerning with the martensitic transformation and SME in Fe-Ni-base alloys. The thermal hysteresis dependence on the alloying elements and thermal treatments are surveyed. The contribution and effect on SME characteristics of widely used alloying elements such as Ti, Nb, Ni, Al, Co, Ta and peculiarities of thermal treatment are discussed. It is noted the main goal of these treatments is to reduce the symmetry of transformation by the ordering or precipitation of a fine coherent phase. The physical principles of transformation hysteresis manipulation in Fe-base alloys is discussed and it concluded that the thermal cycling behavior of Fe-base alloys is very complex and is not clearly understood at present. On the other hand, it is pointed out that thermal cycling is an effective method for control and improvement of SME in these alloys. It is concluded that Fe-base alloys are highly evolved shape memory materials-having a wide working range, good workability and are relatively cheap. In addition, the properties are easily controlled by suitably alloying, aging and thermal cycling. (orig.)

Thermodynamic properties and atomic structure of Ca-based liquid alloys

Science.gov (United States)

Poizeau, Sophie

To identify the most promising positive electrodes for Ca-based liquid metal batteries, the thermodynamic properties of diverse Ca-based liquid alloys were investigated. The thermodynamic properties of Ca-Sb alloys were determined by emf measurements. It was found that Sb as positive electrode would provide the highest voltage for Ca-based liquid metal batteries (1 V). The price of such a battery would be competitive for the grid-scale energy storage market. The impact of Pb, a natural impurity of Sb, was predicted successfully and confirmed via electrochemical measurements. It was shown that the impact on the open circuit voltage would be minor. Indeed, the interaction between Ca and Sb was demonstrated to be much stronger than between Ca and Pb using thermodynamic modeling, which explains why the partial thermodynamic properties of Ca would not vary much with the addition of Pb to Sb. However, the usage of the positive electrode would be reduced, which would limit the interest of a Pb-Sb positive electrode. Throughout this work, the molecular interaction volume model (MIVM) was used for the first time for alloys with thermodynamic properties showing strong negative deviation from ideality. This model showed that systems such as Ca-Sb have strong short-range order: Ca is most stable when its first nearest neighbors are Sb. This is consistent with what the more traditional thermodynamic model, the regular association model, would predict. The advantages of the MIVM are the absence of assumption regarding the composition of an associate, and the reduced number of fitting parameters (2 instead of 5). Based on the parameters derived from the thermodynamic modeling using the MIVM, a new potential of mixing for liquid alloys was defined to compare the strength of interaction in different Ca-based alloys. Comparing this trend with the strength of interaction in the solid state of these systems (assessed by the energy of formation of the intermetallics), the systems with

Shape recovery characteristics of biaxially prestrained Fe-Mn-Si-based shape memory alloy

International Nuclear Information System (INIS)

Wada, M.; Naoi, H.; Yasuda, H.; Maruyama, T.

2008-01-01

Fe-Mn-Si-based shape memory alloy has already been used practically for steel pipe joints. In most of the applications including the steel pipe joints, it is possible to estimate the reduction of diameter from the experimental data of the shape recovery after uniaxial stretching of the alloy materials. However, studies on shape recovery effects after biaxial stretching are important for the extensive applications of the alloy. In this study, we investigated the shape recovery strain after uniaxial and biaxial stretching and the microstructures of the alloy in order to see the effects of uniaxial and biaxial prestrain on the stress-induced martensitic transformation. Amounts of shape recovery strain in the biaxially prestrained specimens are smaller than those in the uniaxially prestrained specimens. Transmission electron microscopy revealed that reverse transformations of stress-induced martensitic ε-phase are prevented by slip bands formed at the same time in the biaxially prestrained specimens, but not in the uniaxially prestrained specimens. The technological data and interpretations presented in this study should be useful in forming design guidelines for promoting the extensive applications of Fe-Mn-Si-based shape memory alloy

Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

International Nuclear Information System (INIS)

Uddin, M S; Hall, Colin; Murphy, Peter

2015-01-01

Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

Science.gov (United States)

Uddin, M S; Hall, Colin; Murphy, Peter

2015-01-01

Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

Metallic ion release from biocompatible cobalt-based alloy

Directory of Open Access Journals (Sweden)

Dimić Ivana D.

2014-01-01

Full Text Available Metallic biomaterials, which are mainly used for the damaged hard tissue replacements, are materials with high strength, excellent toughness and good wear resistance. The disadvantages of metals as implant materials are their susceptibility to corrosion, the elastic modulus mismatch between metals and human hard tissues, relatively high density and metallic ion release which can cause serious health problems. The aim of this study was to examine metallic ion release from Co-Cr-Mo alloy in artificial saliva. In that purpose, alloy samples were immersed into artificial saliva with different pH values (4.0, 5.5 and 7.5. After a certain immersion period (1, 3 and 6 weeks the concentrations of released ions were determined using Inductively Coupled Plasma - Mass Spectrophotometer (ICP-MS. The research findings were used in order to define the dependence between the concentration of released metallic ions, artificial saliva pH values and immersion time. The determined released metallic ions concentrations were compared with literature data in order to describe and better understand the phenomenon of metallic ion release from the biocompatible cobalt-based alloy. [Projekat Ministarstva nauke Republike Srbije, br. III 46010 i br. ON 174004

Corrosion resistance of tantalum base alloys

International Nuclear Information System (INIS)

Gypen, L.A.; Brabers, M.; Deruyttre, A.

1984-01-01

The corrosion behaviour of substitutional Ta-Mo, Ta-W, Ta-Nb, Ta-Hf, Ta-Zr, Ta-Re, Ta-Ni, Ta-V, Ta-W-Mo, Ta-W-Nb, Ta-W-Hf and Ta-W-Re alloys has been investigated in various corrosive media, i.e. (1) concentrated sulfuric acid at 250 0 C and 200 0 C, (2) boiling hydrochloric acid of azeotropic composition, (3) concentrated hydrochloric acid at 150 0 C under pressure, (4) HF-Containing solutions and (5) 0.5% H 2 SO 4 at room temperature (anodisation). In highly corrosive media such as concentrated H 2 SO 4 at 250 0 C and concentrated HCl at 150 0 C tantalum is hydrogen embrittled, probably by stress induced precipitation of β-hydride. Both corrosion rate and hydrogen embrittlement in concentrated H 2 SO 4 at 250 0 C are strongly influenced by alloying elements. Small alloying additions of either Mo or Re decrease the corrosion rate and the hydrogen embrittlement, while Hf has the opposite effect. Hydrogen embrittlement in concentrated H 2 SO 4 at 250 0 C is completely eliminated by alloying Ta with 1 to 3 at % Mo (0.5 to 1.5 wt % Mo). These results can be explained in terms of oxygen deficiency of the Ta 2 O 5 film and the electronic structure of these alloys. (orig.) [de

Hydrogen absorption/desorption properties in the TiCrV based alloys

Directory of Open Access Journals (Sweden)

A. Martínez

2012-10-01

Full Text Available Three different Ti-based alloys with bcc structure and Laves phase were studied. The TiCr1.1V0.9, TiCr1.1V0.45Nb0.45 and TiCr1.1V0.9 + 4%Zr7Ni10 alloys were melted in arc furnace under argon atmosphere. The hydrogen absorption capacity was measured by using aparatus type Sievert's. Crystal structures, and the lattice parameters were determined by using X-ray diffraction, XRD. Microestructural analysis was performed by scanning electron microscope, SEM and electron dispersive X-ray, EDS. The hydrogen storage capacity attained a value of 3.6 wt. (% for TiCr1.1V0.9 alloy in a time of 9 minutes, 3.3 wt. (% for TiCr1.1V0.45Nb0.45 alloy in a time of 7 minutes and 3.6 wt. (% TiCr1.1V0.9 + 4%Zr7Ni10 with an increase of the hydrogen absorption kinetics attained in 2 minutes. This indicates that the addition of Nb and 4%Zr7Ni10 to the TiCrV alloy acts as catalysts to accelerate the hydrogen absorption kinetics.

Zr - based alloys as hydride electrodes in Ni-MH batteries

International Nuclear Information System (INIS)

Biris, A.R.; Biris, A.S.; Misan, I.; Lupu, D.

1999-01-01

Hydrogen storage alloys, MH, are already used in Ni-MH alkaline batteries conquering an important share of the rechargeable nickel-cadmium battery market. This remarkable success is due not only to the replacement of the toxic material, cadmium, by metal hydrides but also to an increased specific energy, which makes them attractive for electric vehicles. Many research groups are concerned in the improvement of the hydride electrode characteristics: hydrogen storage capacity, high-rate discharge ability, increased cycle life. These properties can be modified by substitution of the base components of a given alloy. A comparison of two types of alloys suitable for MH electrodes LaNi 5 able to store 1.36 w/o hydrogen with Zr(Ti)-Ni alloys of the AB 2 Laves phase type structure showed that the latter could absorb higher amounts of hydrogen. We report part of studies on Zr-V-Cr-Ni of the 15 C type Laves phase structure using our original procedure for pasted electrodes. The substitution of Cr for V atoms in ZrV 0.5 Ni 1 . 5 did not increase the discharge capacity. However, it proved to have a remarkable effect on the discharge capacity C at low temperatures. C at - 12 deg. C as compared to 20 deg.C increases up to ∼ 65 % for Cr containing alloys. (authors)

Corrosion and oxidation of vanadium-base alloys in helium environments

International Nuclear Information System (INIS)

Loomis, B.A.; Smith, D.L.

1984-01-01

The increase in weight of unalloyed V and V-5Ti, V-15Cr and V-15Cr-5Ti alloys at 725, 825 and 925 K was determined for exposure times ranging up to 1000 hours in He containing H 2 and/or H 2 O impurity. The microhardness of the specimens in a transverse section was also determined after exposure for 1000 hours. These results were utilized to discuss the consequences of the selection of certain radiation-damage resistant, V-base alloys for structural materials applications in a fusion reactor

Quality assurance when surface welding nickel-based alloys; Qualitaetssicherung bei der Auftragsschweissung von Nickelbasislackierungen

Energy Technology Data Exchange (ETDEWEB)

Metschke, J. [Muellkraftwerk Schwandorf Betriebsgesellschaft mbH (Germany)

2003-07-01

The cladding of evaporator heat exchanger surfaces in refuse incineration boilers with alloy 625 can effectively protect against the corrosive wear of the basic tube if the described rules concerning the pre-treatment, processing, quality control and after-care are observed. This statement is supported by the positive experience with this alloy at the Schwandorf refuse-fired power plant over a period of eight years now. Since the maximum service temperature is limited to 420 C, alloy 625 is only suitable for protecting superheater pipes subject to certain conditions. Long-term experience with alternative nickel-based alloys (alloy 622, alloy 686 and others) are not yet available. (orig.) [German] Die Schweissplattierung von Verdampferwaermetauscherflaechen in Muellverbrennungskesseln mit Alloy 625 kann einen wirksamen Schutz gegen den korrosiven Verschleiss des Grundrohres darstellen, wenn die vorstehenden Regeln ueber Vorbehandlung, Verarbeitung, Qualitaetskontrolle und laufende Nachsorgearbeiten beachtet werden. Diese Aussage wird durch die positiven Erfahrungen mit dieser Legierung im Muellkraftwerk Schwandorf ueber einen Zeitraum von nunmehr acht Jahren gestuetzt. (orig.)

Correlation Between Superheated Liquid Fragility And Onset Temperature Of Crystallization For Al-Based Amorphous Alloys

Directory of Open Access Journals (Sweden)

Guo J.

2015-06-01

Full Text Available Amorphous alloys or metallic glasses have attracted significant interest in the materials science and engineering communities due to their unique physical, mechanical, and chemical properties. The viscous flow of amorphous alloys exhibiting high strain rate sensitivity and homogeneous deformation is considered to be an important characteristic in thermoplastic forming processes performed within the supercooled liquid region because it allows superplastic-like deformation behavior. Here, the correlation between the superheated liquid fragility, and the onset temperature of crystallization for Al-based alloys, is investigated. The activation energy for viscous flow of the liquid is also investigated. There is a negative correlation between the parameter of superheated liquid fragility and the onset temperature of crystallization in the same Al-based alloy system. The activation energy decreases as the onset temperature of crystallization increases. This indicates that the stability of a superheated liquid can affect the thermal stability of the amorphous alloy. It also means that a liquid with a large superheated liquid fragility, when rapidly solidified, forms an amorphous alloy with a low thermal stability.

Straining electrode behavior and corrosion resistance of nickel base alloys in high temperature acidic solution

International Nuclear Information System (INIS)

Yamanaka, Kazuo

1992-01-01

Repassivation behavior and IGA resistance of nickel base alloys containing 0∼30 wt% chromium was investigated in high temperature acid sulfate solution. (1) The repassivation rate was increased with increasing chromium content. And so the amounts of charge caused by the metal dissolution were decreased with increasing chromium content. (2) Mill-annealed Alloy 600 suffered IGA at low pH environment below about 3.5 at the fixed potentials above the corrosion potential in 10%Na 2 SO 4 +H 2 SO 4 solution at 598K. On the other hand, thermally-treated Alloy 690 was hard to occur IGA at low pH environments which mill-annealed Alloy 600 occurred IGA. (3) It was considered that the reason, why nickel base alloys containing high chromium content such as Alloy 690 (60%Ni-30%Cr-10%Fe) had high IGA/SCC resistance in high temperature acidic solution containing sulfate ion, is due to both the promotion of the repassivation and the suppression of the film dissolution by the formation of the dense chromium oxide film

Neutronics and activation analysis of lithium-based ternary alloys in IFE blankets

Energy Technology Data Exchange (ETDEWEB)

Jolodosky, Alejandra, E-mail: aleja311@berkeley.edu [University of California Berkeley, Berkeley, CA 94706 (United States); Kramer, Kevin [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA (United States); Meier, Wayne; DeMuth, James; Reyes, Susana [TerraPower, Bellevue, WA 98005 (United States); Fratoni, Massimiliano [University of California Berkeley, Berkeley, CA 94706 (United States)

2016-06-15

Highlights: • Monte Carlo calculations were performed on numerous lithium ternary alloys. • Elements with high neutron multiplication performed well with low absorbers. • Enriching lithium decreases minimum lithium concentration of alloys by 60% or more. • Alloys that performed well neutronically were selected for activation calculations. • Alloys activated, except LiBaBi, do not pose major environmental or safety concerns. - Abstract: An attractive feature of using liquid lithium as the breeder and coolant in fusion blankets is that it has very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns. The Lawrence Livermore National Laboratory is carrying an effort to develop a lithium-based ternary alloy that maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) and at the same time reduces overall flammability concerns. This study evaluates the neutronics performance of lithium-based alloys in the blanket of an inertial fusion energy chamber in order to inform such development. 3-D Monte Carlo calculations were performed to evaluate two main neutronics performance parameters for the blanket: tritium breeding ratio (TBR), and the fusion energy multiplication factor (EMF). It was found that elements that exhibit low absorption cross sections and higher q-values such as Pb, Sn, and Sr, perform well with those that have high neutron multiplication such as Pb and Bi. These elements meet TBR constrains ranging from 1.02 to 1.1. However, most alloys do not reach EMFs greater than 1.15. Additionally, it was found that enriching lithium with {sup 6}Li significantly increases the TBR and decreases the minimum lithium concentration by more than 60%. The amount of enrichment depends on how much total lithium is in the alloy to begin with. Alloys that performed well in the TBR

Corrosion of nickel-base heat resistant alloys in simulated VHTR coolant helium at very high temperatures

International Nuclear Information System (INIS)

Shindo, Masami; Kondo, Tatsuo

1976-01-01

A comparative evaluation was made on three commercial nickel-base heat resistant alloys exposed to helium-base atmosphere at 1000 0 C, which contained several impurities in simulating the helium cooled very high temperature nuclear reactor (VHTR) environment. The choice of alloys was made so that the effect of elements commonly found in commercial alloys were typically examined. The corrosion in helium at 1000 0 C was characterized by the sharp selection of thermodynamically unstable elements in the oxidizing process and the resultant intergranular penetration and internal oxidation. Ni-Cr-Mo-W type solution hardened alloy such as Hastelloy-X showed comparatively good resistance. The alloy containing Al and Ti such as Inconel-617 suffered adverse effect in contrast to its good resistance to air oxidation. The alloy nominally composed only of noble elements, Ni, Fe and Mo, such as Hastelloy-B showed least apparent corrosion, while suffered internal oxidation due to small amount of active impurities commonly existing in commercial heats. The results were discussed in terms of selection and improvement of alloys for uses in VHTR and the similar systems. (auth.)

Fabrication and nano-imprintabilities of Zr-, Pd- and Cu-based glassy alloy thin films

International Nuclear Information System (INIS)

Takenaka, Kana; Saidoh, Noriko; Nishiyama, Nobuyuki; Inoue, Akihisa

2011-01-01

With the aim of investigating nano-imprintability of glassy alloys in a film form, Zr 49 Al 11 Ni 8 Cu 32 , Pd 39 Cu 29 Ni 13 P 19 and Cu 38 Zr 47 Al 9 Ag 6 glassy alloy thin films were fabricated on Si substrate by a magnetron sputtering method. These films exhibit a very smooth surface, a distinct glass transition phenomenon and a large supercooled liquid region of about 80 K, which are suitable for imprinting materials. Moreover, thermal nano-imprintability of these obtained films is demonstrated by using a dot array mold with a dot diameter of 90 nm. Surface observations revealed that periodic nano-hole arrays with a hole diameter of 90 nm were successfully imprinted on the surface of these films. Among them, Pd-based glassy alloy thin film indicated more precise pattern imprintability, namely, flatter residual surface plane and sharper hole edge. It is said that these glassy alloy thin films, especially Pd-based glassy alloy thin film, are one of the promising materials for fabricating micro-machines and nano-devices by thermal imprinting.

Thermodynamic properties of uranium in gallium–aluminium based alloys

International Nuclear Information System (INIS)

Volkovich, V.A.; Maltsev, D.S.; Yamshchikov, L.F.; Chukin, A.V.; Smolenski, V.V.; Novoselova, A.V.; Osipenko, A.G.

2015-01-01

Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

Thermodynamic properties of uranium in gallium–aluminium based alloys

Energy Technology Data Exchange (ETDEWEB)

Volkovich, V.A., E-mail: v.a.volkovich@urfu.ru [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Maltsev, D.S.; Yamshchikov, L.F. [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Chukin, A.V. [Department of Theoretical Physics and Applied Mathematics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Smolenski, V.V.; Novoselova, A.V. [Institute of High-Temperature Electrochemistry UD RAS, Ekaterinburg, 620137 (Russian Federation); Osipenko, A.G. [JSC “State Scientific Centre - Research Institute of Atomic Reactors”, Dimitrovgrad, 433510 (Russian Federation)

2015-10-15

Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

Fragility of superheated melts and glass-forming ability in Pr-based alloys

International Nuclear Information System (INIS)

Meng, Q.G.; Zhou, J.K.; Zheng, H.X.; Li, J.G.

2006-01-01

The kinetic viscosity (η) of superheated melts, thermal properties (T x , T m , T L ) and X-ray diffraction analysis on the Pr-based bulk metallic glasses (BMG) are reported and discussed. A new refined concept, the superheated fragility defined as M' = E S δ x /k B , has been developed based on common solidification theory and the Arrhenius equation. The interrelationship between this kind of fragility and the glass-forming ability (GFA) is elaborated on and evaluated in Pr-based BMG and Al-based amorphous ribbon alloys. Using viscosity data of superheated melts, it is shown, theoretically and experimentally, that the fragility parameter M' may be used as a GFA indicator for metallic alloys

Dual Microstructure Heat Treatment of a Nickel-Base Disk Alloy Assessed

Science.gov (United States)

Gayda, John

2002-01-01

Gas turbine engines for future subsonic aircraft will require nickel-base disk alloys that can be used at temperatures in excess of 1300 F. Smaller turbine engines, with higher rotational speeds, also require disk alloys with high strength. To address these challenges, NASA funded a series of disk programs in the 1990's. Under these initiatives, Honeywell and Allison focused their attention on Alloy 10, a high-strength, nickel-base disk alloy developed by Honeywell for application in the small turbine engines used in regional jet aircraft. Since tensile, creep, and fatigue properties are strongly influenced by alloy grain size, the effect of heat treatment on grain size and the attendant properties were studied in detail. It was observed that a fine grain microstructure offered the best tensile and fatigue properties, whereas a coarse grain microstructure offered the best creep resistance at high temperatures. Therefore, a disk with a dual microstructure, consisting of a fine-grained bore and a coarse-grained rim, should have a high potential for optimal performance. Under NASA's Ultra-Safe Propulsion Project and Ultra-Efficient Engine Technology (UEET) Program, a disk program was initiated at the NASA Glenn Research Center to assess the feasibility of using Alloy 10 to produce a dual-microstructure disk. The objectives of this program were twofold. First, existing dual-microstructure heat treatment (DMHT) technology would be applied and refined as necessary for Alloy 10 to yield the desired grain structure in full-scale forgings appropriate for use in regional gas turbine engines. Second, key mechanical properties from the bore and rim of a DMHT Alloy 10 disk would be measured and compared with conventional heat treatments to assess the benefits of DMHT technology. At Wyman Gordon and Honeywell, an active-cooling DMHT process was used to convert four full-scale Alloy 10 disks to a dual-grain microstructure. The resulting microstructures are illustrated in the

Compatibility between vandium-base alloys and flowing lithium: Partitioning of hydrogen at elevated temperatures

International Nuclear Information System (INIS)

Hull, A.B.; Chopra, O.K.; Loomis, B.; Smith, D.

1989-12-01

A major concern in fusion reactor design is possible hydrogen-isotope-induced embrittlement of structural alloys in the neutron environment expected in these reactors. Hydrogen fractionation occurs between lithium and various refractory metals according to a temperature-dependent distribution coefficient, K H , that is defined as the ration of the hydrogen concentration in the metallic specimen to that in the liquid lithium. In the present work, K H was determined for pure vanadium and several binary and ternary alloys, and the commercial Vanstar 7. Hydrogen distribution studies were performed in an austenitic steel forced-circulation lithium loop. Equilibrium concentrations of hydrogen in vanadium-base alloys exposed to flowing lithium at temperatures of 350 to 550 degree C were measured by inert gas fusion techniques and residual gas analysis. Thermodynamic calculations are consistent with the effect of chromium and titanium in the alloys on the resultant hydrogen fractionation. Experimental and calculated results indicate that K H values are very low; i.e., the hydrogen concentrations in the lithium-equilibrated vanadium-base alloy specimens are about two orders of magnitude lower than those in the lithium. Because of this low distribution coefficient, embrittlement of vanadium alloys by hydrogen in lithium would not be expected. 15 refs., 5 figs., 4 tabs

Techniques for intergranular crack formation and assessment in alloy 600 base and alloy 182 weld metals

International Nuclear Information System (INIS)

Lee, Tae Hyun; Hwang, Il Soon; Kim, Hong Deok; Kim, Ji Hyun

2015-01-01

A technique developed to produce artificial intergranular stress corrosion cracks in structural components was applied to thick, forged alloy 600 base and alloy 182 weld metals for use in the qualification of nondestructive examination techniques for welded components in nuclear power plants. An externally controlled procedure was demonstrated to produce intergranular stress corrosion cracks that are comparable to service-induced cracks in both the base and weld metals. During the process of crack generation, an online direct current potential drop method using array probes was used to measure and monitor the sizes and shapes of the cracks. A microstructural characterization of the produced cracks revealed realistic conformation of the crack faces unlike those in machined notches produced by an electrodischarge machine or simple fatigue loading using a universal testing machine. A comparison with a destructive metallographic examination showed that the characteristics, orientations, and sizes of the intergranular cracks produced in this study are highly reproducible.

Quantitative assessment of intergranular damage due to PWR primary water exposure in structural Ni-based alloys

International Nuclear Information System (INIS)

Ter-Ovanessian, Benoît; Deleume, Julien; Cloué, Jean-Marc; Andrieu, Eric

2013-01-01

Highlights: ► IG damage occurred on Ni-base alloys during exposure at high temperature water. ► Two characterization methods yield a tomographic analysis of this IG damage. ► Connected or isolated intergranular oxygen/oxide penetrations are quantified. ► Such quantitative description provides information on IGSCC susceptibility. - Abstract: Two nickel-based alloys, alloy 718 and alloy 600, known to have different resistances to IGSCC, were exposed to a simulated PWR primary water environment at 360 °C for 1000 h. The intergranular oxidation damage was analyzed in detail using an original approach involving two characterization methods (Incremental Mechanical Polishing/Microcopy procedure and SIMS imaging) which yielded a tomographic analysis of the damage. Intergranular oxygen/oxide penetrations occurred either as connected or isolated penetrations deep under the external oxide/substrate interface as far as 10 μm for alloy 600 and only 4 μm for alloy 718. Therefore, assessing this damage precisely is essential to interpret IGSCC susceptibility.

First-principles investigations of iron-based alloys and their properties

Science.gov (United States)

Limmer, Krista Renee

Fundamental understanding of the complex interactions governing structure-property relationships in iron-based alloys is necessary to advance ferrous metallurgy. Two key components of alloy design are carbide formation and stabilization and controlling the active deformation mechanism. Following a first-principles methodology, understanding on the electronic level of these components has been gained for predictive modeling of alloys. Transition metal carbides have long played an important role in alloy design, though the complexity of their interactions with the ferrous matrix is not well understood. Bulk, surface, and interface properties of vanadium carbide, VCx, were calculated to provide insight for the carbide formation and stability. Carbon vacancy defects are shown to stabilize the bulk carbide due to increased V-V bonding in addition to localized increased V-C bond strength. The VCx (100) surface energy is minimized when carbon vacancies are at least two layers from the surface. Further, the Fe/VC interface is stabilized through maintaining stoichiometry at the Fe/VC interface. Intrinsic and unstable stacking fault energy, gammaisf and gamma usf respectively, were explicitly calculated in nonmagnetic fcc Fe-X systems for X = Al, Si, P, S, and the 3d and 4d transition elements. A parabolic relationship is observed in gamma isf across the transition metals with minimums observed for Mn and Tc in the 3d and 4d periods, respectively. Mn is the only alloying addition that was shown to decrease gamma isf in fcc Fe at the given concentration. The effect of alloying on gammausf also has a parabolic relationship, with all additions decreasing gammaisf yielding maximums for Fe and Rh.

Alloy 690 in PWR type reactors; Aleaciones base niquel en condiciones de primario de los reactores tipo PWR

Energy Technology Data Exchange (ETDEWEB)

Gomez Briceno, D.; Serrano, M.

2005-07-01

Alloy 690, used as replacement of Alloy 600 for vessel head penetration (VHP) nozzles in PWR, coexists in the primary loop with other components of Alloy 600. Alloy 690 shows an excellent resistance to primary water stress corrosion cracking, while Alloy 600 is very susceptible to this degradation mechanisms. This article analyse comparatively the PWSCC behaviour of both Ni-based alloys and associated weld metals 52/152 and 82/182. (Author)

Effects of composition on the order-disorder transformation in Ni-Cr based alloys

International Nuclear Information System (INIS)

Marucco, A.

1991-01-01

The Ni-Cr based alloys undergo an ordering transformation, due to the formation of an ordered Ni 2 Cr phase, which causes a lattice contraction and it is responsisble for ''negative creep'' or excessive stresses in constrained components. A short-range ordered (SRO) structure develops in the matrix phase after solution treatment and at early stages of ageing, which can transform to a long-range ordered (LRO) structure, depending on the alloy composition and on time and temperature of ageing, upon prolonged annealing below the critical temperature. In stoichiometric Ni 2 Cr alloy LRO forms in a few hours, but in off-stoichiometric alloys the transformation kinetics are very sluggish and LRO takes several tens of thousands of hours to form, when it forms. The ordering behaviours of stoichiometric Ni 2 Cr and Ni 3 Cr were studied by means of isothermal treatments in the temperature range 450-600degC for different ageing times up to 30 000 h, followed by lattice parameter measurements by X-ray diffraction and electrical resistivity measurements. Similar studies performed on a series of ternary Ni-Cr-Fe alloys revealed the dependence of the degree of order on Cr concentration and a markedly delaying influence of Fe on the ordering kinetics. Finally, long-term microstructural stability of some commercial Ni-Cr based alloys, widely used for high temperature applications, have been studied: the ordering behaviour and associated microstructural changes are discussed in this paper

Hot-working behavior of an advanced intermetallic multi-phase γ-TiAl based alloy

Energy Technology Data Exchange (ETDEWEB)

Schwaighofer, Emanuel, E-mail: emanuel.schwaighofer@unileoben.ac.at [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria); Clemens, Helmut [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria); Lindemann, Janny [Chair of Physical Metallurgy and Materials Technology, Brandenburg University of Technology, Konrad-Wachsmann-Allee 17, D-03046 Cottbus (Germany); GfE Fremat GmbH, Lessingstr. 41, D-09599 Freiberg (Germany); Stark, Andreas [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Mayer, Svea [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria)

2014-09-22

New high-performance engine concepts for aerospace and automotive application enforce the development of lightweight intermetallic γ-TiAl based alloys with increased high-temperature capability above 750 °C. Besides an increased creep resistance, the alloy system must exhibit sufficient hot-workability. However, the majority of current high-creep resistant γ-TiAl based alloys suffer from poor workability, whereby grain refinement and microstructure control during hot-working are key factors to ensure a final microstructure with sufficient ductility and tolerance against brittle failure below the brittle-to-ductile transition temperature. Therefore, a new and advanced β-solidifying γ-TiAl based alloy, a so-called TNM alloy with a composition of Ti–43Al–4Nb–1Mo–0.1B (at%) and minor additions of C and Si, is investigated by means of uniaxial compressive hot-deformation tests performed with a Gleeble 3500 simulator within a temperature range of 1150–1300 °C and a strain rate regime of 0.005–0.5 s{sup −1} up to a true deformation of 0.9. The occurring mechanisms during hot-working were decoded by ensuing constitutive modeling of the flow curves by a novel phase field region-specific surface fitting approach via a hyperbolic-sine law as well as by evaluation through processing maps combined with microstructural post-analysis to determine a safe hot-working window of the refined TNM alloy. Complementary, in situ high energy X-ray diffraction experiments in combination with an adapted quenching and deformation dilatometer were conducted for a deeper insight about the deformation behavior of the alloy, i.e. phase fractions and texture evolution as well as temperature uncertainties arising during isothermal and non-isothermal compression. It was found that the presence of β-phase and the contribution of particle stimulated nucleation of ζ-Ti{sub 5}Si{sub 3} silicides and h-type carbides Ti{sub 2}AlC enhance the dynamic recrystallization behavior during

Hot-working behavior of an advanced intermetallic multi-phase γ-TiAl based alloy

International Nuclear Information System (INIS)

Schwaighofer, Emanuel; Clemens, Helmut; Lindemann, Janny; Stark, Andreas; Mayer, Svea

2014-01-01

New high-performance engine concepts for aerospace and automotive application enforce the development of lightweight intermetallic γ-TiAl based alloys with increased high-temperature capability above 750 °C. Besides an increased creep resistance, the alloy system must exhibit sufficient hot-workability. However, the majority of current high-creep resistant γ-TiAl based alloys suffer from poor workability, whereby grain refinement and microstructure control during hot-working are key factors to ensure a final microstructure with sufficient ductility and tolerance against brittle failure below the brittle-to-ductile transition temperature. Therefore, a new and advanced β-solidifying γ-TiAl based alloy, a so-called TNM alloy with a composition of Ti–43Al–4Nb–1Mo–0.1B (at%) and minor additions of C and Si, is investigated by means of uniaxial compressive hot-deformation tests performed with a Gleeble 3500 simulator within a temperature range of 1150–1300 °C and a strain rate regime of 0.005–0.5 s −1 up to a true deformation of 0.9. The occurring mechanisms during hot-working were decoded by ensuing constitutive modeling of the flow curves by a novel phase field region-specific surface fitting approach via a hyperbolic-sine law as well as by evaluation through processing maps combined with microstructural post-analysis to determine a safe hot-working window of the refined TNM alloy. Complementary, in situ high energy X-ray diffraction experiments in combination with an adapted quenching and deformation dilatometer were conducted for a deeper insight about the deformation behavior of the alloy, i.e. phase fractions and texture evolution as well as temperature uncertainties arising during isothermal and non-isothermal compression. It was found that the presence of β-phase and the contribution of particle stimulated nucleation of ζ-Ti 5 Si 3 silicides and h-type carbides Ti 2 AlC enhance the dynamic recrystallization behavior during deformation within

The Hydrogen Pickup Behavior for Zirconium-based Alloys in Various Out-of-pile Corrosion Test Conditions

Energy Technology Data Exchange (ETDEWEB)

Aomi, M.; Etoh, Y.; Ishimoto, S.; Une, K. [Nippon Nuclear Fuel Development, Co., Ltd., 2163 Narita-cho, Oarai-machi, Ibaraki-ken, 311-1313 (Japan); Ito, K. [Global Nuclear Fuel Japan Co., Ltd., 3-1 Uchikawa 2-chome, Yokosuka-shi, Kanagawa-ken, 239-0836 (Japan)

2009-06-15

An acceleration of hydrogen absorption in zirconium alloy claddings at high burnups is one of the most important issues limiting the fuel performance from the viewpoint of cladding integrity. In this context, advanced cladding materials with higher corrosion resistant and lower hydrogen absorption properties have been widely searched in various organizations. In this study, four kinds of zirconium-based alloys, whose in-pile data had been acquired [1,2] were subjected to comprehensive out-of-pile corrosion tests with various temperature and atmosphere conditions in order to investigate the correlation between in-pile and out-of-pile corrosion and hydrogen pick-up behavior, i.e. Zry-2, GNF-Ziron (Zry-2-based alloy with {approx}0.25 wt % of Fe), Hi-FeNi Zircaloy (Zry-2-based alloy with {approx}0.25 wt % of Fe and {approx}0.1 wt% Ni), and VB (Zr-based alloy containing Sn, Cr, and {approx}0.5 wt % of Fe). All the alloys were annealed in RXA condition. The out-of-pile corrosion tests were carried out in three different conditions of 400 deg. C steam, 475 deg. C supercritical water, and 290 deg. C LiOH aqueous solution. In addition to these alloys, several Zry-2-based alloys with various iron contents were tested in 290 deg. C LiOH aqueous solution. Among the four corrosion conditions, the 290 deg. C LiOH aqueous solution test well screened the hydrogen pick-up behavior of the alloys. The hydrogen absorption decreased with higher iron contents in the alloys in both the out-of-pile and in-pile conditions. Especially, the distinct suppression of hydrogen absorption was observed for VB with the highest iron content. The similar dependence of iron content on the hydrogen pick-up fraction was also obtained for the Zry-2-based alloys with different iron contents, which were corroded in the 290 deg. C LiOH aqueous solution condition. As for the corrosion behavior in the 290 deg. C LiOH aqueous solution condition, the weight gains of Zry-2, GNF-Ziron and VB followed the 1

Biocompatibility of dental alloys

Energy Technology Data Exchange (ETDEWEB)

Braemer, W. [Heraeus Kulzer GmbH and Co. KG, Hanau (Germany)

2001-10-01

Modern dental alloys have been used for 50 years to produce prosthetic dental restorations. Generally, the crowns and frames of a prosthesis are prepared in dental alloys, and then veneered by feldspar ceramics or composites. In use, the alloys are exposed to the corrosive influence of saliva and bacteria. Metallic dental materials can be classified as precious and non-precious alloys. Precious alloys consist of gold, platinum, and small amounts of non-precious components such as copper, tin, or zinc. The non-precious alloys are based on either nickel or cobalt, alloyed with chrome, molybdenum, manganese, etc. Titanium is used as Grade 2 quality for dental purposes. As well as the dental casting alloys, high purity electroplated gold (99.8 wt.-%) is used in dental technology. This review discusses the corrosion behavior of metallic dental materials with saliva in ''in vitro'' tests and the influence of alloy components on bacteria (Lactobacillus casei and Streptococcus mutans). The test results show that alloys with high gold content, cobalt-based alloys, titanium, and electroplated gold are suitable for use as dental materials. (orig.)

Au-Ge based Candidate Alloys for High-Temperature Lead-Free Solder Alternatives

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

2009-01-01

Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The influence of the low melting point metals namely In, Sb and Sn to the Au-Ge eutectic with respect to the microstructure and microhard......Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The influence of the low melting point metals namely In, Sb and Sn to the Au-Ge eutectic with respect to the microstructure...... was primarily strengthened by the refined (Ge) dispersed phase. The distribution of phases played a relatively more crucial role in determining the ductility of the bulk solder alloy. In the present work it was found that among the low melting point metals, the addition of Sb to the Au-Ge eutectic would...

Advanced Class of FML on the Base Al-Li Alloy 1441 with Lower Density

Science.gov (United States)

Antipov, V. V.; Senatorova, O. G.; Lukina, N. F.

Structure, composition, properties combination of specimens and components, a number of technological parameters for production of advanced FML based on high-modulus Al-Li 1441 alloy (E 79 GPa) with reduced density (d 2.6 g/m3) and optimized adhesive prepreg reinforced with high-strength high-modulus VMP glass fibres are described. Service life 1441 alloy provides the possibility of manufacture of thin sheets (up to 0.3 mm), clad and unclad. Moreover, some experience on the usage of 1441 T1, T11 sheets and shapes in Be 200 and Be 103 aircraft was accumulated. The class of FML materials based on Al-Li alloy provide an 5% improvement in weight efficiency and stiffness of skin structures as compared with those made from FML with conventional Al-Cu-Mg (2024T3 a.o.) and Al-Zn-Mg-Cu (7475T76 a.o.) alloys.

Detection and distribution of lithium in Mg-Li-Al based alloy by ToF-SIMS

Energy Technology Data Exchange (ETDEWEB)

Kumar, Vinod, E-mail: vkt.meta@mnit.ac.in [Metallurgical and Materials Engineering, MNIT Jaipur, 302017 (India); Adjunct Faculty, Materials Research Centre, MNIT Jaipur, 302017 (India)

2016-12-01

Highlights: • First time, Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) is used to investigate the surface as well as bulk microstructural features of novel Mg-Li-Al based alloy. • There are six multi-oxide layers present within the surface film of LATZ9531R. • Secondary ion imaging by ToF-SIMS with mass contrast effect (including Li) is possible for a multiphase lithium-containing alloy systems. - Abstract: Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) is used to investigate the surface as well as bulk microstructural features of novel Mg-Li-Al based alloy namely Mg-9Li-7Al-3Sn-1Zn (LATZ9531). ToF-SIMS study indicates that there are six multi-oxide layers present within the surface film of LATZ9531. Furthermore, The presence of Li containing phase has been qualitatively confirmed based on the high number of Li-ion counts in SIMS, and the same is verified quantitatively by using electron probe microanalysis (EPMA). The novel approach may be useful to determine the chemical composition of the phases in various alloys which has lighter alloying elements such as lithium.

Microstructure-based modeling of tensile deformation of a friction stir welded AZ31 Mg alloy

Energy Technology Data Exchange (ETDEWEB)

He, Weijun, E-mail: weijun.he@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Zheng, Li [College of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Xin, Renlong, E-mail: rlxin@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Liu, Qing [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China)

2017-02-27

The deformation and fracture behaviors of friction stir welded (FSWed) Mg alloys are topics under investigation. The microstructure and texture of a FSWed Mg alloy were characterized by electron back scattered diffraction. Four characteristic sub-zones with different orientations in the FSWed Mg alloy joint were identified. The texture distribution across the stir zones and transition zone were obviously inhomogeneous. For comparison, four sub-regions in the base material were also characterized. Based on the experimental microstructure and texture, a crystal plasticity finite element model was developed to represent the friction stir welded Mg alloy. Simulations were carried out to study the effect of texture variation on the deformation behaviors during transverse tension. Compared with the base material case, strong macroscopic strain localization was observed for the FSWed joint case after transverse tension. Strain localization may have contributed to the decayed elongation of the FSWed joint in the transverse tension. Texture variation in the thermal-mechanical affected zone did not change the deformation mechanism in the stir zones, while it did decrease the strain localization, thus assuming to improve the elongation of the friction stir welded Mg alloy.

Microstructure-based modeling of tensile deformation of a friction stir welded AZ31 Mg alloy

International Nuclear Information System (INIS)

He, Weijun; Zheng, Li; Xin, Renlong; Liu, Qing

2017-01-01

The deformation and fracture behaviors of friction stir welded (FSWed) Mg alloys are topics under investigation. The microstructure and texture of a FSWed Mg alloy were characterized by electron back scattered diffraction. Four characteristic sub-zones with different orientations in the FSWed Mg alloy joint were identified. The texture distribution across the stir zones and transition zone were obviously inhomogeneous. For comparison, four sub-regions in the base material were also characterized. Based on the experimental microstructure and texture, a crystal plasticity finite element model was developed to represent the friction stir welded Mg alloy. Simulations were carried out to study the effect of texture variation on the deformation behaviors during transverse tension. Compared with the base material case, strong macroscopic strain localization was observed for the FSWed joint case after transverse tension. Strain localization may have contributed to the decayed elongation of the FSWed joint in the transverse tension. Texture variation in the thermal-mechanical affected zone did not change the deformation mechanism in the stir zones, while it did decrease the strain localization, thus assuming to improve the elongation of the friction stir welded Mg alloy.

Short-Range-Order for fcc-based Binary Alloys Revisited from Microscopic Geometry

Science.gov (United States)

Yuge, Koretaka

2018-04-01

Short-range order (SRO) in disordered alloys is typically interpreted as competition between chemical effect of negative (or positive) energy gain by mixing constituent elements and geometric effects comes from difference in effective atomic radius. Although we have a number of theoretical approaches to quantitatively estimate SRO at given temperatures, it is still unclear to systematically understand trends in SRO for binary alloys in terms of geometric character, e.g., effective atomic radius for constituents. Since chemical effect plays significant role on SRO, it has been believed that purely geometric character cannot capture the SRO trends. Despite these considerations, based on the density functional theory (DFT) calculations on fcc-based 28 equiatomic binary alloys, we find that while conventional Goldschmidt or DFT-based atomic radius for constituents have no significant correlation with SRO, atomic radius for specially selected structure, constructed purely from information about underlying lattice, can successfully capture the magnitude of SRO. These facts strongly indicate that purely geometric information of the system plays central role to determine characteristic disordered structure.

Formation and crystallization kinetics of Nd-Fe-B-based bulk amorphous alloy

Energy Technology Data Exchange (ETDEWEB)

Wu, Qiong; Ge, Hongliang; Zhang, Pengyue; Li, Dongyun; Wang, Zisheng [China Jiliang University, Magnetism Key Laboratory of Zhejiang Province, Hangzhou (China)

2014-06-15

In order to improve the glass-forming ability (GFA) of Nd-Fe-B ternary alloys to obtain fully amorphous bulk Nd-Fe-B-based alloy, the effects of Mo and Y doping on GFA of the alloys were investigated. It was found that the substitution of Mo for Fe and Y for Nd enhanced the GFA of the Nd-Y-Fe-Mo-B alloys. It was also revealed that the GFA of the samples was optimized by 4 at.% Mo doping and increased with theYcontent. The fully amorphous structures were all formed in the Nd{sub 6-x}Y{sub x}Fe{sub 68}Mo{sub 4}B{sub 22} (x =1-5) alloy rods with 1.5 mm-diameter. After subsequent crystallization, the devitrified Nd{sub 3}Y{sub 3}Fe{sub 68}Mo{sub 4}B{sub 22} alloy rod exhibited a uniform distribution of grains with a coercivity of 364.1 kA/m. The crystallization behavior of Nd{sub 3}Y{sub 3}Fe{sub 68}Mo{sub 4}B{sub 22} BMG was investigated in isothermal situation. The Avrami exponent n determined by JAM plot is lower than 2.5, implying that the crystallization is mainly governed by a growth of particles with decreasing nucleation rate. (orig.)

Composition Optimization of Lithium-Based Ternary Alloy Blankets for Fusion Reactors

Science.gov (United States)

Jolodosky, Alejandra

The goal of this dissertation is to examine the neutronic properties of a novel type of fusion reactor blanket material in the form of lithium-based ternary alloys. Pure liquid lithium, first proposed as a blanket for fusion reactors, is utilized as both a tritium breeder and a coolant. It has many attractive features such as high heat transfer and low corrosion properties, but most importantly, it has a very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns including degradation of the concrete containment structure. The work of this thesis began as a collaboration with Lawrence Livermore National Laboratory in an effort to develop a lithium-based ternary alloy that can maintain the beneficial properties of lithium while reducing the reactivity concerns. The first studies down-selected alloys based on the analysis and performance of both neutronic and activation characteristics. First, 3-D Monte Carlo calculations were performed to evaluate two main neutronics performance parameters for the blanket: tritium breeding ratio (TBR), and energy multiplication factor (EMF). Alloys with adequate results based on TBR and EMF calculations were considered for activation analysis. Activation simulations were executed with 50 years of irradiation and 300 years of cooling. It was discovered that bismuth is a poor choice due to achieving the highest decay heat, contact dose rates, and accident doses. In addition, it does not meet the waste disposal ratings (WDR). The straightforward approach to obtain Monte Carlo TBR and EMF results required 231 simulations per alloy and became computationally expensive, time consuming, and inefficient. Consequently, alternate methods were pursued. A collision history-based methodology recently developed for the Monte Carlo code Serpent, calculates perturbation effects on practically

Fatigue Strength Estimation Based on Local Mechanical Properties for Aluminum Alloy FSW Joints

Directory of Open Access Journals (Sweden)

Kittima Sillapasa

2017-02-01

Full Text Available Overall fatigue strengths and hardness distributions of the aluminum alloy similar and dissimilar friction stir welding (FSW joints were determined. The local fatigue strengths as well as local tensile strengths were also obtained by using small round bar specimens extracted from specific locations, such as the stir zone, heat affected zone, and base metal. It was found from the results that fatigue fracture of the FSW joint plate specimen occurred at the location of the lowest local fatigue strength as well as the lowest hardness, regardless of microstructural evolution. To estimate the fatigue strengths of aluminum alloy FSW joints from the hardness measurements, the relationship between fatigue strength and hardness for aluminum alloys was investigated based on the present experimental results and the available wide range of data from the references. It was found as: σa (R = −1 = 1.68 HV (σa is in MPa and HV has no unit. It was also confirmed that the estimated fatigue strengths were in good agreement with the experimental results for aluminum alloy FSW joints.

Evaluation of mechanically alloyed Cu-based powders as filler alloy for brazing tungsten to a reduced activation ferritic-martensitic steel

Energy Technology Data Exchange (ETDEWEB)

Prado, J. de, E-mail: javier.deprado@urjc.es; Sánchez, M.; Ureña, A.

2017-07-15

80Cu-20Ti powders were evaluated for their use as filler alloy for high temperature brazing of tungsten to a reduced activation ferritic/martensitic steel (Eurofer), and its application for the first wall of the DEMO fusion reactor. The use of alloyed powders has not been widely considered for brazing purposes and could improve the operational brazeability of the studied system due to its narrower melting range, determined by DTA analysis, which enhances the spreading capabilities of the filler. Ti contained in the filler composition acts as an activator element, reacting and forming several interfacial layers at the Eurofer-braze, which enhances the wettability properties and chemical interaction at the brazing interface. Brazing thermal cycle also activated the diffusion phenomena, which mainly affected to the Eurofer alloying elements causing in it a softening band of approximately 400 μm of thickness. However, this softening effect did not degrade the shear strength of the brazed joints (94 ± 23 MPa), because failure during testing was always located at the tungsten-braze interface. - Highlights: •W-Eurofer brazed joints, manufactured using Cu-based mechanically alloyed powders as filler is proposed. •The benefits derivate from the alloyed composition could improve the operational brazeability of the studied system. •Tested pre-alloyed fillers have a more homogeneous melting stage which enhances its spreading and flowing capabilities. •This behaviour could lead to work with higher heating rates and lower brazing temperatures.

Atomic scale properties of magnetic Mn-based alloys probed by emission Mössbauer spectroscopy

CERN Multimedia

Mn-based alloys are characterized by a wealth of properties, which are of interest both from fundamental physics point of view and particularly attractive for different applications in modern technology: from magnetic storage to sensing and spin-based electronics. The possibility to tune their magnetic properties through post-growth thermal processes and/or stoichiometry engineering is highly important in order to target different applications (i.e. Mn$_{x}$Ga) or to increase their Curie temperature above room temperature (i.e. off-stoichiometric MnSi). In this project, the Mössbauer effect will be applied at $^{57}$Fe sites following implantation of radioactive $^{57}$Mn, to probe the micro-structure and magnetism of Mn-based alloys on the atomic-scale. The proposed experimental plan is devoted to establish a direct correlation between the local structure and bulk magnetism (and other physical properties) of Mn-based alloys.

Electrode characteristics of the (Mm)Ni 5-based hydrogen storage alloys

Energy Technology Data Exchange (ETDEWEB)

Han, Dong Soo; Choi, Seung Jun; Chang, Min Ho; Choi, Jeon; Park, Choong Nyun [Chonnam National University, Kwangju (Korea, Republic of)

1995-06-01

The MmNi-based alloy electrode was studied for use a negative electrode in Ni-MH battery. Alloys with MmNi{sub 5}-{sub x} M{sub x}(M=Co,Al,Mn) composition were synthesized, and their electrode characteristics of activation rate, temperature dependence, electrode capacity and cycle life were investigated. With increasing Al content and decreasing Mn content in the alloys, the discharge capacity increased while the cycle life decreased. As x in MmNi{sub 5}-{sub x} M{sub x} increased from 1.5 to 2.0, decreasing the Ni content, the discharge capacity, the low temperature property and the rate capability decreased. However its cycle life was improved. Increasing Co content resulted in a prolonged cycle life and decrease of high rate discharge capacity. It can be concluded that the most promising alloy in view of discharge capacity and cycle life is MmNi{sub 3}.5 Co{sub 0}.7 Al{sub 0}.5 Mn{sub 0}.3. (author). 9 refs., 9 figs., 1 tab.

Monte Carlo simulation of ordering transformations in Ni-Mo-based alloys

International Nuclear Information System (INIS)

Kulkarni, U.D.

2004-01-01

The quenched in state of short range order (SRO) in binary Ni-Mo alloys is characterized by intensity maxima at {1 (1/2) 0} and equivalent positions in the reciprocal space. Ternary addition of a small amount of Al to the binary alloy, on the other hand, leads to a state of SRO that gives rise to intensity maxima at {1 0 0} and equivalent, in addition to {1 (1/2) 0} and equivalent, positions in the selected area electron diffraction patterns. Different geometric patterns of streaks of diffuse intensity, joining the SRO maxima with the superlattice positions of the emerging long range ordered (LRO) structures or in some cases between the superlattice positions of different LRO structures, are observed during the SRO-to-LRO transitions in the Ni-Mo-based and other 1 (1/2) 0 alloys. Monte Carlo simulations have been carried out here in order to shed some light on the atomic structures of the SRO and the SRO-to-LRO transition states in these alloys

Low in reactor creep Zr-base alloy tubes

International Nuclear Information System (INIS)

Cheadle, B.A.; Holt, R.A.

1984-01-01

This invention relates to zirconium alloy tubes especially for use in nuclear power reactors. More particularly it relates to quaternary 3.5 percent Sn, 1 percent Mo, 1 percent Nb, balance Zr alloy tubes which have been extruded, cold worked and heat treated to lower their dislocation density. In one embodiment the alloys are cold worked less than 5 percent and stress relieved to produce a low dislocation density and in another embodiment the alloys are cold worked up to about 50 percent and annealed to produce a very low dislocation density and also small equiaxed β grains

On the use of titanium hydride for powder injection moulding of titanium-based alloys

International Nuclear Information System (INIS)

Carrenoo-Morelli, E.; Bidaux, J.-E.

2009-01-01

Full text: Titanium and titanium-based alloys are excellent materials for a number of engineering applications because of their high strength, lightweight, good corrosion resistance, non magnetic characteristic and biocompatibility. The current processing steps are usually costly, and there is a growing demand for net-shape solutions for manufacturing parts of increasing complexity. Powder injection moulding is becoming a competitive alternative, thanks to the advances in production of good quality base-powders, binders and sintering facilities. Titanium hydride powders, have the attractiveness of being less reactive than fine titanium powders, easier to handle, and cheaper. This paper summarizes recent advances on PIM of titanium and titanium alloys from TiH2 powders, including shape-memory NiTi alloys. (author)

The properties of samarium-doped zinc oxide/phthalocyanine structure for optoelectronics prepared by pulsed laser deposition and organic molecular evaporation

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Marešová, Eva; Fitl, Přemysl; Vlček, Jan; Bergmann, M.; Vondráček, Martin; Yatskiv, Roman; Bulíř, Jiří; Hubík, Pavel; Hruška, Petr; Drahokoupil, Jan; Abdellaoui, N.; Vrňata, M.; Lančok, Ján

2016-01-01

Roč. 122, č. 3 (2016), 1-8, č. článku 225. ISSN 0947-8396 R&D Projects: GA MŠk(CZ) LG15050; GA ČR(CZ) GAP108/11/0958; GA MŠk(CZ) LM2011029; GA ČR(CZ) GA14-10279S; GA MŠk(CZ) 7AMB14FR010 Institutional support: RVO:68378271 ; RVO:67985882 Keywords : samarium-doped zinc oxide zinc/phthalocyanine deposition * evaporation * pulsed laser deposition * thin films Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.455, year: 2016

Development of new zirconium based alloys for burn-up extension of light water reactor fuels, (1)

International Nuclear Information System (INIS)

Isobe, Takeshi; Matsuo, Yutaka

1992-01-01

Steam corrosion tests and tensile were conducted to investigate the effects of alloying elements such as Sn, Nb, Fe, Cr, Mo and V, and the mechanical properties of Nb-containing Zr-base alloys. The corrosion resistance of Zr-base alloys in comparison to Zr'y-4 was significantly improved by the reduction of the Sn content by 0.5 wt% and by a small addition of Nb (about 0.05 to 0.2 wt%). However, the decrease in solute Sn atoms degraded mechanical properties. The increase of the total content of Fe and Cr from 0.3 to 0.7 wt% improved the mechanical properties without affecting the corrosion resistance. The decrease of the Fe/Cr ratio from 6.0 to 0.5 increased the corrosion resistance. Small addition of Mo and/or V resulted in a further improvement of mechanical properties. Based on these experiments, three Nb-containing Zr-base alloys with equivalent mechanical properties and superior corrosion resistance to Zr'y-4 were developed. (author)

Advanced ordered intermetallic alloy deployment

Energy Technology Data Exchange (ETDEWEB)

Liu, C.T.; Maziasz, P.J.; Easton, D.S. [Oak Ridge National Lab., TN (United States)

1997-04-01

The need for high-strength, high-temperature, and light-weight materials for structural applications has generated a great deal of interest in ordered intermetallic alloys, particularly in {gamma}-based titanium aluminides {gamma}-based TiAl alloys offer an attractive mix of low density ({approximately}4g/cm{sup 3}), good creep resistance, and high-temperature strength and oxidation resistance. For rotating or high-speed components. TiAl also has a high damping coefficient which minimizes vibrations and noise. These alloys generally contain two phases. {alpha}{sub 2} (DO{sub 19} structure) and {gamma} (L 1{sub 0}), at temperatures below 1120{degrees}C, the euticoid temperature. The mechanical properties of TiAl-based alloys are sensitive to both alloy compositions and microstructure. Depending on heat-treatment and thermomechanical processing, microstructures with near equiaxed {gamma}, a duplex structure (a mix of the {gamma} and {alpha}{sub 2} phases) can be developed in TiAl alloys containing 45 to 50 at. % Al. The major concern for structural use of TiAl alloys is their low ductility and poor fracture resistance at ambient temperatures. The purpose of this project is to improve the fracture toughness of TiAl-based alloys by controlling alloy composition, microstructure and thermomechanical treatment. This work is expected to lead to the development of TiAl alloys with significantly improved fracture toughness and tensile ductility for structural use.

Nickel-base alloy overlay weld with improved ultrasonic flaw detection by magnetic stirring welding

International Nuclear Information System (INIS)

Takashi, Hirano; Kenji, Hirano; Masayuki, Watando; Takahiro, Arakawa; Minoru, Maeda

2001-01-01

Ultrasonic flaw detection is more difficult in Nickel-base alloy welds containing dendrites owing to the decrease ultrasonic transmissibility they cause. The present paper discusses application of magnetic stirring welding as a means for reducing dendrite growth with consequent improvement in ultrasonic transmissibility. Single pass and multi-pass welding tests were conducted to determine optimal welding conditions. By PT and macro observation subsequent to welding was carried out, optimal operation conditions were clarified. Overlay welding tests and UT clearly indicated ultrasonic beam transmissibility in overlay welds to be improved and detection capacity to be greater through application of magnetic stirring welding. Optimal operation conditions were determined based on examination of temper bead effects in the heat affected zone of low alloy steel by application of magnetic stirring welding to the butt welded joints between low alloy and stainless steel. Hardness in this zone of low alloy steel after the fourth layer was less than 350 HV. (author)

Synthesis and characterization of Mg-based amorphous alloys and their use for decolorization of Azo dyes

International Nuclear Information System (INIS)

Iqbal, M; Wang, W H

2014-01-01

Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 alloys were prepared by melt spinning technique by using 3-4N pure metals. Characterization of the samples was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and energy dispersive x-ray analyzer (EDAX). Microstructural investigations were conducted by using scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as optical and stereo scan microscopy techniques. DSC results showed multistage crystallization. Activation energy was found to be 225 kJ/mol by Kissinger method indicating good thermal stability against crystallization. XRD, DSC, SEM and EDS (energy dispersive spectroscopy) results are agreed very well. In order to study decolorization, the MSRs of Mg 70 Zn 25 Ca 5 Mg 68 Zn 27 Ca 5 alloys were treated repeatedly with various azo dyes at room temperature. In order to compare the results, MSRs of amorphous Zr- and Ni-based metallic glasses were also treated. Reaction of MSRs with azo dyes results in their decolorization in a few hours. Decolorization of azo dyes takes place by introducing amorphous MSRs which results in breaking the -N=N- bonds that exist in dye contents. It is concluded that Mg-based alloys are useful for paint and dye industries and will be beneficial to control water pollution. Comparison of results showed that Mg-based alloys are more efficient than Zr- and Ni-based amorphous alloys for decolorization of azo dyes

Cross sections for d-{sup 3}H neutron interactions with samarium isotopes

Energy Technology Data Exchange (ETDEWEB)

Luo, Junhua; He, Long [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering; Wu, Chunlei; Jiang, Li [Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry

2016-11-01

The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the {sup 149}Sm(n,p){sup 149}Pm reaction are reported for the first time. The cross sections of the {sup 150}Sm(n,p){sup 150}Pm, {sup 144}Sm(n,p){sup 144}Pm, {sup 152}Sm(n,α){sup 149}Nd and {sup 144}Sm(n,α){sup 141}Nd reactions at different neutron energies reported in the present work can be added as new data in the nuclear databases.

Translating VDM to Alloy

DEFF Research Database (Denmark)

Lausdahl, Kenneth

2013-01-01

specifications. However, to take advantage of the automated analysis of Alloy, the model-oriented VDM specifications must be translated into a constraint-based Alloy specifications. We describe how a sub- set of VDM can be translated into Alloy and how assertions can be expressed in VDM and checked by the Alloy...

Thermodynamics of coproportionation reactions of homogeneous samarium (3) and yttrium (3) nitrates solvates with neutral organic phosphorus compounds

International Nuclear Information System (INIS)

Pyartman, A.K.

1995-01-01

Reaction heats of homogeneous samarium (3) and yttrium (3) nitrate solvates coproportionation with neutral organophosphoric compounds (tri-n.-butylphosphate, diisooctylmethylphosphonate, diisoamylmethylphosphonate) at T=298.15 K in hexane have been measured by thermochemical method. It has been ascertained that enthalpies of coproportionation reactions practically do not depend on the nature, concentration of rare earth metal (3) nitrate solvates in hexane, nature of neutral organophosphoric compound and constitute 1.1±-.2 kJ/mol. The Gibbs free energy of coproportionation reactions is -5.43 kJ/mol, while entropy of the reactions in 14.5±0.7 J/mol·K. 8 refs., 1 tab

Nickel base alloys

International Nuclear Information System (INIS)

Gibson, R.C.; Korenko, M.K.

1980-01-01

The specified alloys consist of Ni, Cr and Fe as main constituents, and Mo, Nb, Si, Zr, Ti, Al, C and B as minor constituents. They are said to exhibit high weldability and long-time structural stability, as well as low swelling under nuclear radiation conditions, making them especially suitable for use as a duct material and control element cladding for sodium-cooled nuclear reactors. (U.K.)

VANADIUM ALLOYS

Science.gov (United States)

Smith, K.F.; Van Thyne, R.J.

1959-05-12

This patent deals with vanadium based ternary alloys useful as fuel element jackets. According to the invention the ternary vanadium alloys, prepared in an arc furnace, contain from 2.5 to 15% by weight titanium and from 0.5 to 10% by weight niobium. Characteristics of these alloys are good thermal conductivity, low neutron capture cross section, good corrosion resistance, good welding and fabricating properties, low expansion coefficient, and high strength.

Stress corrosion cracking of nickel base alloys in PWR primary water

International Nuclear Information System (INIS)

Guerre, C.; Chaumun, E.; Crepin, J.; De Curieres, I.; Duhamel, C.; Heripre, E.; Herms, E.; Laghoutaris, P.; Molins, R.; Sennour, M.; Vaillant, F.

2013-01-01

Stress corrosion cracking (SCC) of nickel base alloys and associated weld metals in primary water is one of the major concerns for pressurized water reactors (PWR). Since the 90's, highly cold-worked stainless steels (non-sensitized) were also found to be susceptible to SCC in PWR primary water ([1], [2], [3]). In the context of the life extension of pressurized water reactors, laboratory studies are performed in order to evaluate the SCC behaviour of components made of nickel base alloys and of stainless steels. Some examples of these laboratory studies performed at CEA will be given in the talk. This presentation deals with both initiation and propagation of stress corrosion cracks. The aims of these studies is, on one hand, to obtain more data regarding initiation time or crack growth rate and, one the other hand, to improve our knowledge of the SCC mechanisms. The aim of these approaches is to model SCC and to predict components life duration. Crack growth rate (CGR) tests on Alloy 82 with and without post weld heat treatment are performed in PWR primary water (Figure 1). The heat treatment seems to be highly beneficial by decreasing the CGR. This result could be explained by the effect of thermal treatment on the grain boundary nano-scopic precipitation in Alloy 82 [4]. The susceptibility to SCC of cold worked austenitic stainless steels is also studied. It is shown that for a given cold-working procedure, SCC susceptibility increases with increasing cold-work ([2], [5]). Despite the fact that the SCC behaviour of Alloy 600 has been widely studied for many years, recent laboratory experiments and analysis ([6], [7], [8]) showed that oxygen diffusion is not a rate-limiting step in the SCC mechanism and that chromium diffusion in the bulk close the crack tip could be a key parameter. (authors)

Hydrogenation properties and microstructure of Ti-Mn-based alloys for hybrid hydrogen storage vessel

International Nuclear Information System (INIS)

Shibuya, Masachika; Nakamura, Jin; Akiba, Etsuo

2008-01-01

Ti-Mn-based AB 2 -type alloys which are suitable for a hybrid hydrogen storage vessel have been synthesized and evaluated hydrogenation properties. As the third element V was added to Ti-Mn binary alloys. All the alloys synthesized in this work mainly consist of the C14 Laves and BCC phase. In the case of Ti0.5V0.5Mn alloy, the amounts of hydrogen absorption was 1.8 wt.% at 243 K under the atmosphere of 7 MPa H 2 , and the hydrogen desorption pressure was in the range of 0.2-0.4 MPa at 243 K. The hydrogen capacity of this alloy did not saturate under 7 MPa H 2 and seems to increase with hydrogen pressure up to 35 MPa that is estimated working pressure of the hybrid hydrogen storage vessel

Corrosion performance of new Zircaloy-2-based alloys

International Nuclear Information System (INIS)

Rudling, P.; Mikes-Lindbaeck, M.; Lethinen, B.; Andren, H.O.; Stiller, K.

1994-01-01

A material development project was initiated to develop a new zirconium alloy, outside the ASTM specifications for Zircaloy-2 and Zircaloy-4, with optimized hydriding and corrosion properties for both boiling water reactors and pressurized water reactors. A number of different alloys were manufactured. These alloys were long-term corrosion tested in autoclaves at 400 C in steam. Also, a 520 C/24 h steam test was carried out. The zirconium metal microstructure and the chemistry of precipitates were characterized by analytical electron microscopy. The metal matrix chemistry was determined by atom probe analysis. The paper describes the correlations between corrosion material performance and zirconium alloy microstructure

Optical modeling of nickel-base alloys oxidized in pressurized water reactor

Energy Technology Data Exchange (ETDEWEB)

Clair, A. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France); Foucault, M.; Calonne, O. [Areva ANP, Centre Technique Departement Corrosion-Chimie, 30 Bd de l' industrie, BP 181, 71205 Le Creusot (France); Finot, E., E-mail: Eric.Finot@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France)

2012-10-01

The knowledge of the aging process involved in the primary water of pressurized water reactor entails investigating a mixed growth mechanism in the corrosion of nickel-base alloys. A mixed growth induces an anionic inner oxide and a cationic diffusion parallel to a dissolution-precipitation process forms the outer zone. The in situ monitoring of the oxidation kinetics requires the modeling of the oxide layer stratification with the full knowledge of the optical constants related to each component. Here, we report the dielectric constants of the alloys 600 and 690 measured by spectroscopic ellipsometry and fitted to a Drude-Lorentz model. A robust optical stratification model was determined using focused ion beam cross-section of thin foils examined by transmission electron microscopy. Dielectric constants of the inner oxide layer depleted in chromium were assimilated to those of the nickel thin film. The optical constants of both the spinels and extern layer were determined. - Highlights: Black-Right-Pointing-Pointer Spectroscopic ellipsometry of Ni-base alloy oxidation in pressurized water reactor Black-Right-Pointing-Pointer Measurements of the dielectric constants of the alloys Black-Right-Pointing-Pointer Optical simulation of the mixed oxidation process using a three stack model Black-Right-Pointing-Pointer Scattered crystallites cationic outer layer; linear Ni-gradient bottom layer Black-Right-Pointing-Pointer Determination of the refractive index of the spinel and the Cr{sub 2}O{sub 3} layers.

Room temperature deformation of in-situ grown quasicrystals embedded in Al-based cast alloy

Directory of Open Access Journals (Sweden)

Boštjan Markoli

2013-12-01

Full Text Available An Al-based cast alloy containing Mn, Be and Cu has been chosen to investigate the room temperature deformation behavior of QC particles embedded in Al-matrix. Using LOM, SEM (equipped with EDS, conventional TEM with SAED and controlled tensile and compression tests, the deformation response of AlMn2Be2Cu2 cast alloy at room temperature has been examined. Alloy consisted of Al-based matrix, primary particles and eutectic icosahedral quasicrystalline (QC i-phase and traces of Θ-Al2Cu and Al10Mn3. Tensile and compression specimens were used for evaluation of mechanical response and behavior of QC i-phase articles embedded in Al-cast alloy. It has been established that embedded QC i-phase particles undergo plastic deformation along with the Al-based matrix even under severe deformation and have the response resembling that of the metallic materials by formation of typical cup-and-cone feature prior to failure. So, we can conclude that QC i-phase has the ability to undergo plastic deformation along with the Al-matrix to greater extent contrary to e.g. intermetallics such as Θ-Al2Cu for instance.

Development of silicide coating over molybdenum based refractory alloy and its characterization

International Nuclear Information System (INIS)

Chakraborty, S.P.; Banerjee, S.; Sharma, I.G.; Suri, A.K.

2010-01-01

Molybdenum based refractory alloys are potential candidate materials for structural applications in high temperature compact nuclear reactors and fusion reactors. However, these alloys being highly susceptible to oxidation in air or oxygen at elevated temperature, undergoes severe losses from highly volatile molybdenum trioxide species. Present investigation, therefore, examines the feasibility of development of silicide type of coating over molybdenum base TZM alloy shape (Mo > 99 wt.%) using pack cementation coating technique. TZM alloy was synthesized in this laboratory from oxide intermediates of MoO 2 , TiO 2 and ZrO 2 in presence of requisite amount of carbon, by alumino-thermic reduction smelting technique. The arc melted and homogenized samples of TZM alloy substrate was then embedded in the chosen and intimately mixed pack composition consisting of inert matrix (Al 2 O 3 ), coating powder (Si) and activator (NH 4 Cl) taken in the judicious proportion. The sealed charge packs contained in an alumina crucible were heated at temperatures of 1000 o C for 8-16 h heating cycle to develop the coating. The coating phase was confirmed to be of made of MoSi 2 by XRD analysis. The morphology of the coating was studied by SEM characterization. It had revealed that the coating was diffusion bonded where Si from coating diffused inward and Mo from TZM substrate diffused outward to form the coating. The coating was found to be resistant to oxidation when tested in air up to 1200 o C. A maximum 100 μm of coating thickness was achieved on each side of the substrate.

Comparison of the tensile bond strength of high-noble, noble, and base metal alloys bonded to enamel.

Science.gov (United States)

Sen, D; Nayir, E; Pamuk, S

2000-11-01

Although the bond strengths of various resin composite luting materials have been reported in the literature, the evaluation of these systems with various cast alloys of different compositions has not been completely clarified. To evaluate the tensile bond strength of sandblasted high-noble, noble, and base metal alloys bonded to etched enamel by 2 different bonding agents of different chemical composition: Panavia-Ex (BIS-GMA) and Super-Bond (4-META acrylic). Flat enamel surfaces were prepared on buccal surfaces of 60 extracted noncarious human incisors. Teeth were divided into 3 groups of 20 each. Twenty circular disks of 5 mm diameter were prepared for casting for each group. Group I was cast with a high-noble, group II with a noble, and group III with a base metal alloy. The surfaces of the disks were sandblasted with 250 microm Al(2)O(3). Ten disks of each group were bonded to exposed enamel surfaces with Super-Bond and 10 disks with Panavia-Ex as recommended by the manufacturer. The tensile bond strength was measured with an Instron universal testing machine with a crosshead speed of 0.5 mm/min until failure occurred. Two-way ANOVA was used to evaluate the results. The differences in bond strengths of Super-Bond and Panavia-Ex with different alloys were not significant. The highest bond strengths were obtained in base metal alloys, followed by noble and high-noble alloys. These results were significant. Panavia-Ex and Super-Bond exhibited comparable tensile bond strengths. For both luting agents, the highest bond strengths were achieved with base metal alloys and the lowest with high-noble alloys.

Structural investigations of mechanical properties of Al based rapidly solidified alloys

International Nuclear Information System (INIS)

Karakoese, Ercan; Keskin, Mustafa

2011-01-01

Highlights: → Rapid solidification processing (RSP) involves exceptionally high cooling rates. → We correlate the microstructure of the intermetallic Al 3 Fe, Al 2 Cu and Al 3 Ni phases with the cooling rate. → The solidification rate is high enough to retain most of alloying elements in the Al matrix. → The rapid solidification has effect on the phase constitution. -- Abstract: In this study, Al based Al-3 wt.%Fe, Al-3 wt.%Cu and Al-3 wt.%Ni alloys were prepared by conventional casting. They were further processed using the melt-spinning technique and characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), differential scanning calorimetry (DSC) and the Vickers microhardness tester. The rapidly solidified (RS) binary alloys were composed of supersaturated α-Al solid solution and finely dispersed intermetallic phases. Experimental results showed that the mechanical properties of RS alloys were enhanced, which can be attributed to significant changes in the microstructure. RS samples were measured using a microhardness test device. The dependence of microhardness H V on the solidification rate (V) was analysed. These results showed that with the increasing values of V, the values of H V increased. The enthalpies of fusion for the same alloys were determined by DSC.

Effect of molybdenum and chromium additions on the mechanical properties of Fe3Al-based alloys

International Nuclear Information System (INIS)

Sun Yangshan; Xue Feng; Mei Jianping; Yu Xingquan; Zhang Lining

1995-01-01

Iron aluminides based on Fe 3 Al offer excellent oxidation and sulfidation resistance, with lower material cost and density than stainless steels. However, their potential use as structural material has been hindered by limited ductility and a sharp drop in strength above 600 C. Recent development efforts have indicated that adequate engineering ductility of 10--20% and tensile yield strength of as high as 500 MPa can be achieved through control of composition and microstructure. These improved tensile properties make Fe 3 Al-based alloys more competitive against conventional austenic and ferritic steels. The improvement of high temperature mechanical properties has been achieved mainly by alloying processes. Molybdenum has been found to be one of the most important alloying elements for strengthening Fe 3 Al-based alloys at high temperatures. However, the RT(room temperature) ductility decreases with the increase of a molybdenum addition. On the other hand, a chromium addition to Fe 3 Al-based alloys is very efficient for improving RT ductility but not beneficial to yield strength at temperatures to 800 C. The purpose of the present paper is to report the effects of combined additions of molybdenum and chromium on mechanical properties at ambient temperature and high temperature of 600 C

Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

International Nuclear Information System (INIS)

Fuchs, G.E.

1995-02-01

The effects of heat treatment and deformation processing on the microstructures and properties of γ-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation γ-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed

Thermodynamic properties of some gallium-based binary alloys

International Nuclear Information System (INIS)

Awe, O.E.; Odusote, Y.A.; Akinlade, O.; Hussain, L.A.

2008-01-01

We have studied the concentration dependence of the free energy of mixing, concentration-concentration fluctuations in the long-wavelength limit, the chemical short-range order parameter, the enthalpy and entropy of mixing of Ga-Zn, Ga-Mg and Al-Ga binary alloys at different temperatures using a quasi-chemical approximation for compound forming binary alloys and that for simple regular alloys. From the study of the thermodynamic quantities, we observed that thermodynamic properties of Ga-Zn and Al-Ga exhibit positive deviations from Raoultian behaviour, while Ga-Mg exhibits negative deviation. Hence, this study reveals that both Ga-Zn and Al-Ga are segregating systems, while chemical order exists in Ga-Mg alloy in the whole concentration range. Furthermore, our investigation indicate that Al-Ga binary alloy have a tendency to exhibit ideal mixture behaviour in the concentration range 0≤c Al ≤0.30 and 0.7≤c Al ≤1

Designing magnetic compensated states in tetragonal Mn{sub 3}Ge-based Heusler alloys

Energy Technology Data Exchange (ETDEWEB)

You, Yurong; Xu, Guizhou, E-mail: gzxu@njust.edu.cn; Hu, Fang; Gong, Yuanyuan; Liu, Er; Peng, Guo; Xu, Feng, E-mail: xufeng@njust.edu.cn

2017-05-01

Magnetic compensated materials attracted much interests due to the observed large exchange bias and large coercivity, and also their potential applications in the antiferromagnetic spintronics with merit of no stray field. In this work, by using ab-initio studies, we designed several Ni (Pd, Pt) doped Mn{sub 3}Ge-based D0{sub 22}-type tetragonal Heusler alloys with fully compensated states. Theoretically, we find the total moment change is asymmetric across the compensation point (at ~x=0.3) in Mn{sub 3-x}Y{sub x}Ge (Y=Ni, Pd, Pt). In addition, an uncommon discontinuous jump is observed across the critical zero-moment point, indicating that some non-trivial properties may emerge at this point. Further electronic analyses of these compensated alloys reveal high spin polarizations at the Fermi level, which is advantageous for spin transfer torque applications. - Highlights: • Several new fully compensated magnetic states are identified in Mn{sub 3}Ge-based tetragonal alloys. • The magnetic moment changes are asymmetric upon Ni, Pd and Pt substitution. • Discontinuous jumps exist across the compensated points. • The three compensated alloys possess large spin polarizations.

High temperature cathodic charging of hydrogen in zirconium alloys and iron and nickel base alloys

International Nuclear Information System (INIS)

John, J.T.; De, P.K.; Gadiyar, H.S.

1990-01-01

These investigations lead to the development of a new technique for charging hydrogen into metals and alloys. In this technique a mixture of sulfates and bisulfates of sodium and potassium is kept saturated with water at 250-300degC in an open pyrex glass beaker and electrolysed using platinum anode and the material to be charged as the cathode. Most of the studies were carried out on Zr alloys. It is shown that because of the high hydrogen flux available at the surface and the high diffusivity of hydrogen in metals at these temperatures the materials pick up hydrogen faster and more uniformly than the conventional electrolytic charging at room temperature and high temperature autoclaving in LiOH solutions. Chemical analysis, metallographic examination and XRD studies confirm this. This technique has been used to charge hydrogen into many iron and nickel base austentic alloys, which are very resistant to hydrogen pick up and to H-embrittlement. Since this involved a novel method of electrolysing water, the hydrogen/deuterium isotopic ratio has been studied. At this temperatures the D/H ratio in the evolved hydrogen gas was found to be closer to the value in the liquid water, which means a smaller separation factor. This confirm the earlier observation that separation factor decreases with increase of temperature. (author). 16 refs., 21 fi gs., 6 tabs

Liquid alkali metals and alkali-based alloys as electron-ion plasmas

International Nuclear Information System (INIS)

Tosi, M.P.

1981-06-01

The article reviews the theory of thermodynamic and structural properties of liquid alkali metals and alkali-based alloys, within the framework of linear screening theory for the electron-ion interactions. (author)

Nanoscale characterization of martensite structures in copper based shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

Adiguzel, O, E-mail: oadiguzel@firat.edu.t [Firat University Department of Physics, 23169 Elazig (Turkey)

2010-11-01

Martensitic transformations are first order displacive transitions and occur in the materials on cooling from high temperature. Shape memory effect is an unusual property exhibited by certain alloy systems, and leads to martensitic transition. Copper-based alloys exhibit this property in beta phase field which possess simple bcc- structures, austenite structure at high-temperatures. As temperature is lowered the austenite undergoes martensitic transition following two ordering reactions, and structural changes in nanoscale govern this transition. Atomic movements are also confined to interatomic lengths in sub-{mu}m or angstrom scale in martensitic transformation. The formation of the layered structures in copper based alloys consists of shears and shear mechanism. Martensitic transformations occur in a few steps with the cooperative movement of atoms less than interatomic distances by means of lattice invariant shears on a {l_brace}110{r_brace} - type plane of austenite matrix which is basal plane or stacking plane of martensite. The lattice invariant shears occurs, in two opposite directions, <110> -type directions on the {l_brace}110{r_brace}-type plane. These shears gives rise to the formation of layered structure.

Surface modification of 5083 Al alloy by electrical discharge alloying processing with a 75 mass% Si-Fe alloy electrode

Energy Technology Data Exchange (ETDEWEB)

Stambekova, Kuralay [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Rd., Taichung 40227, Taiwan (China); Lin, Hung-Mao [Department of Mechanical Engineering, Far East University, No. 49, Zhonghua Rd., Xinshi Dist., Tainan City 74448, Taiwan (China); Uan, Jun-Yen, E-mail: jyuan@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Rd., Taichung 40227, Taiwan (China)

2012-03-01

This study experimentally investigates the surface modification of 5083 Al alloy by the electrical discharge alloying (EDA) process with a Si-Fe alloy as an electrode. Samples were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), micro-hardness and corrosion resistance tests. The micro-hardness of EDA alloyed layer was evidently higher than that of the base metal (5083 Al alloy). The TEM results show that the matrix of the alloyed layer has an amorphous-like structure; the matrix contains fine needle-like Si particles, block-like Si particles and nano-size Al{sub 4.5}FeSi and Al{sub 13}Fe{sub 4} particles. The TEM results support experimental results for the high hardness of the alloyed layer. Moreover, the EDA alloyed layer with composite microstructures has good corrosion resistance in NaCl aqueous solution.

Magnetic properties of Co and Ni based alloy nanoparticles dispersed in a silica matrix

Energy Technology Data Exchange (ETDEWEB)

De Julian Fernandez, C. E-mail: dejulian@padova.infm.it; Sangregorio, C.; Mattei, G.; Maurizio, C.; Battaglin, G.; Gonella, F.; Lascialfari, A.; Lo Russo, S.; Gatteschi, D.; Mazzoldi, P.; Gonzalez, J.M.; D' Acapito, F

2001-04-01

A comparative study of the magnetic properties of Co and Ni based alloy nanoparticles (Ni-Co, Ni-Cu and Co-Cu) formed in a silica matrix by ion implantation is presented. Different ion doses and implantation sequences were realized in order to obtain different nanostructures. The structural and magnetic properties observed for the Cu{sub 50}Ni{sub 50} nanoparticles are similar to those of the Cu{sub 60}Ni{sub 40} bulk alloy. The crystal structure of Co{sub x}Ni{sub 1-x} (0{<=}x{<=}1) nanoparticles is similar to that of the corresponding bulk alloy. The magnetic properties depend on the ion-implanted dose and on the alloy composition. The samples prepared by implanting a 15x10{sup 16} ions/cm{sup 2} total dose contain nanoparticles, which are superparamagnetic at room temperature and their magnetic behavior is influenced by dipolar interparticle interactions. The magnetization of the CoNi samples at high magnetic field is larger than that of the corresponding bulk alloy and follows the same composition dependence of that quantity measured in the alloy.

Magnetic properties of Co and Ni based alloy nanoparticles dispersed in a silica matrix

International Nuclear Information System (INIS)

De Julian Fernandez, C.; Sangregorio, C.; Mattei, G.; Maurizio, C.; Battaglin, G.; Gonella, F.; Lascialfari, A.; Lo Russo, S.; Gatteschi, D.; Mazzoldi, P.; Gonzalez, J.M.; D'Acapito, F.

2001-01-01

A comparative study of the magnetic properties of Co and Ni based alloy nanoparticles (Ni-Co, Ni-Cu and Co-Cu) formed in a silica matrix by ion implantation is presented. Different ion doses and implantation sequences were realized in order to obtain different nanostructures. The structural and magnetic properties observed for the Cu 50 Ni 50 nanoparticles are similar to those of the Cu 60 Ni 40 bulk alloy. The crystal structure of Co x Ni 1-x (0≤x≤1) nanoparticles is similar to that of the corresponding bulk alloy. The magnetic properties depend on the ion-implanted dose and on the alloy composition. The samples prepared by implanting a 15x10 16 ions/cm 2 total dose contain nanoparticles, which are superparamagnetic at room temperature and their magnetic behavior is influenced by dipolar interparticle interactions. The magnetization of the CoNi samples at high magnetic field is larger than that of the corresponding bulk alloy and follows the same composition dependence of that quantity measured in the alloy

Advancement of Compositional and Microstructural Design of Intermetallic γ-TiAl Based Alloys Determined by Atom Probe Tomography

Science.gov (United States)

Klein, Thomas; Clemens, Helmut; Mayer, Svea

2016-01-01

Advanced intermetallic alloys based on the γ-TiAl phase have become widely regarded as most promising candidates to replace heavier Ni-base superalloys as materials for high-temperature structural components, due to their facilitating properties of high creep and oxidation resistance in combination with a low density. Particularly, recently developed alloying concepts based on a β-solidification pathway, such as the so-called TNM alloy, which are already incorporated in aircraft engines, have emerged offering the advantage of being processible using near-conventional methods and the option to attain balanced mechanical properties via subsequent heat-treatment. Development trends for the improvement of alloying concepts, especially dealing with issues regarding alloying element distribution, nano-scale phase characterization, phase stability, and phase formation mechanisms demand the utilization of high-resolution techniques, mainly due to the multi-phase nature of advanced TiAl alloys. Atom probe tomography (APT) offers unique possibilities of characterizing chemical compositions with a high spatial resolution and has, therefore, been widely used in recent years with the aim of understanding the materials constitution and appearing basic phenomena on the atomic scale and applying these findings to alloy development. This review, thus, aims at summarizing scientific works regarding the application of atom probe tomography towards the understanding and further development of intermetallic TiAl alloys. PMID:28773880

Inconel type resistive alloys based on ultrahigh purity nickel

International Nuclear Information System (INIS)

Matsarin, K.A.; Matsarin, S.K.

2000-01-01

The new nickel high-ohm alloys (ρ = 1.2-1.4 μOhm · m), containing the W, Al, Mo alloying elements in the quantity, not exceeding their solubility in a solid solution, are developed on the basis of the Inconel-type standard alloy. The optical composition of the alloy was determined by the results of the alloy was determined by the results of the electric resistance measurement and technological effectiveness indices (relative to the pressure and workable metal yield). The following optimal component concentrations were established: 14-17 %Cr; 10-12 %Fe; 0.5-1.0 %Cu; 1.0-1.5 %Mn; 0.1-0.2 %C; 0.4-0.6 %Si; 0.5-3.0 %W; 5-16 %Mo; 0.5-2.0 %Al; the remainder - Ni. The new alloys are recommended as materials for resistive elements of direct-glow cathode nodes of low capacity electron tubes [ru

Shape memory and pseudoelastic properties of Fe-Mn-Si and Ti-Ni based alloys

International Nuclear Information System (INIS)

Guenin, G.

1997-01-01

The aim of this presentation is to analyse and discuss some recent advances in shape memory and pseudoelastic properties of different alloys. Experimental work in connection with theoretical ones will be reviewed. The first part is devoted to the microstructural origin of shape memory properties of Fe-Mn-Si based alloys (γ-ε transformation); the second part is a synthetic analysis of the effects of thermomechanical treatments on shape memory and pseudoelastic effects in Ti-Ni alloys, with some focus on the behaviour of the R phase introduced. (orig.)

High temperature steam oxidation of Al3Ti-based alloys for the oxidation-resistant surface layer on Zr fuel claddings

International Nuclear Information System (INIS)

Park, Jeong-Yong; Kim, Il-Hyun; Jung, Yang-Il; Kim, Hyun-Gil; Park, Dong-Jun; Choi, Byung-Kwon

2013-01-01

We investigated the feasibility to apply Al 3 Ti-based alloys as the surface layer for improving the oxidation resistance of Zr fuel claddings under accident conditions. Two types of Al 3 Ti-based alloys with the compositions of Al–25Ti–10Cr and Al–21Ti–23Cr in atomic percent were prepared by arc-melting followed by homogenization annealing at 1423 K for 48 h. Al–25Ti–10Cr alloy showed an L1 2 quasi-single phase microstructure with a lot of needle-shaped minor phase and pores. Al–21Ti–23Cr alloy consisted of an L1 2 matrix and Cr 2 Al as the second phase. Al 3 Ti-based alloys showed an extremely low oxidation rate in a 1473 K steam for up to 7200 s when compared to Zircaloy-4. Both alloys exhibited almost the same oxidation rate in the early stage of oxidation, but Al–25Ti–10Cr showed a little lower oxidation rate after 4000 s than Al–21Ti–23Cr. The difference in the oxidation rate between two types of Al 3 Ti-based alloys was too marginal to distinguish the oxidation behavior of each alloy. The resultant oxide exhibited almost the same characteristics in both alloys even though the microstructure was explicitly distinguished from each other. The crystal structure of the oxide formed up to 2000 s was identified as Al 2 O 3 in both alloys. The oxide morphology consisted of columnar grains whose length was almost identical to the average oxide thickness. On the basis of the results obtained, it is considered that Al 3 Ti-based alloy is one of the promising candidates for the oxidation-resistant surface layer on Zr fuel claddings

Lifetime assessment of thick-walled components made of nickel-base alloys under near-service loading conditions

International Nuclear Information System (INIS)

Hueggenberg, Daniel

2015-01-01

Until 2050 the renewable energies should provide 80% of the power in Germany according to Renewable Energy law. Due to that reason the conventional power plants are not used for base load, but rather for the supply of average and peak load. The change of the operating mode leads to shorter times at stationary temperatures and the number of faster start-ups/shut-downs of the power plants will increase. As a result of this the components are exposed to an interacting load of creep and fatigue which reduces the lifetimes. The aim of this thesis is the development and verification of a lifetime assessment procedure for components made of the nickel-base alloys Alloy 617 mod. and Alloy 263 under creep fatigue loading conditions based on numerical phenomenological models and on the approaches of different standards/recommendations. The focus lies on two components of the high temperature material test rig II (HWT II), a header made of Alloy 617 mod. and Alloy 263 as well as a formed part made of Alloy 617 mod. For the basis characterization of the HWT II melts, specimens of the Alloy 617 mod. and Alloy 263 are tested in uniaxial tensile tests, (creep-)fatigue tests, creep tests and charpy tests in a temperature range between 20 C and 725 C. From the comparisons of the test results and the material specifications respectively the results of the projects COORETEC DE4, MARCKO DE2 and MARCKO700 no deviations were obvious for both materials with the exception of the creep test results with Alloy 617 mod. material. The creep tests with Alloy 617 mod. material of the HWT II melt show differences regarding the deformation and damage behavior. In addition to the basis characterization tests some complex lab tests for the characterization of the material behavior under creep-fatigue and multiaxial loading conditions were conducted. The developments of the microstructure, the precipitations as well as the structure of dislocations are investigated in the light optical microscope

Fatigue properties of MA 6000E, a gamma-prime strengthened ODS alloy. [Oxide Dispersion Strengthened Ni-base alloy for gas turbine blade applications

Science.gov (United States)

Kim, Y. G.; Merrick, H. F.

1980-01-01

MA 6000E is a corrosion resistant, gamma-prime strengthened ODS alloy under development for advanced turbine blade applications. The high temperature, 1093 C, rupture strength is superior to conventional nickel-base alloys. This paper addresses the fatigue behavior of the alloy. Excellent properties are exhibited in low and high cycle fatigue and also thermal fatigue. This is attributed to a unique combination of microstructural features, i.e., a fine distribution of dispersed oxides and other nonmetallics, and the highly elongated grain structure which advantageously modify the deformation characteristics and crack initiation and propagation modes from that characteristic of conventional gamma-prime hardened superalloys.

Production and characterization of stainless steel based Fe-Cr-Ni-Mn-Si(-Co) shape memory alloys

International Nuclear Information System (INIS)

Otubo, J.

1995-01-01

It is well known that the Fe based alloys can exhibit shape memory effect due to the γ to ε martensitic transformation. The effect may not be as striking as observed in the NiTi alloy but it might become attractive from the practical point of view. In this work, two compositions of Fe-Cr-Ni-Mn-Si(-Co) stainless steel based shape memory alloy, prepared by the VIM technique, will be presented. The results are good with shape recovery of 95% for a pre-strain of 4% after some training cycles. In terms of workability the alloys produced are worse than the usual AISI304. However, adjusting the thermo-mechanical processing, it is perfectly possible to produce wire as thin as 1,20mm in dia. or down. (orig.)

An experimental study of the magnetic ordering in Pd-based Fe and Mn alloys

International Nuclear Information System (INIS)

Verbeek, B.H.

1979-01-01

This thesis presents the results of an investigation on the magnetic ordering phenomena in some Pd based alloys with small concentrations of magnetic impurities. It has been the object to explore the ordering mechanisms in these alloys which lead to various types of magnetism at low temperature. The experimental techniques used are described. (Auth.)

High-temperature deformation of a mechanically alloyed niobium-yttria alloy

International Nuclear Information System (INIS)

Chou, I.; Koss, D.A.; Howell, P.R.; Ramani, A.S.

1997-01-01

Mechanical alloying (MA) and hot isostatic pressing have been used to process two Nb alloys containing yttria particles, Nb-2 vol.%Y 2 O 3 and Nb-10 vol.%Y 2 O 3 . Similar to some thermomechanically processed nickel-based alloys, both alloys exhibit partially recrystallized microstructures, consisting of a 'necklace' of small recrystallized grains surrounding much larger but isolated, unrecrystallized, cold-worked grains. Hot compression tests from 1049 to 1347 C (0.5-0.6T MP ) of the 10% Y 2 O 3 alloy show that MA material possesses a much higher yield and creep strength than its powder-blended, fully recrystallized counterpart. In fact, the density-compensated specific yield strength of the MA Nb-10Y 2 O 3 exceeds that of currently available commercial Nb alloys. (orig.)

Development of aluminide coatings on vanadium-base alloys in liquid lithium

International Nuclear Information System (INIS)

Park, J.H.; Dragel, D.

1993-01-01

Aluminide coatings were produced on vanadium and vanadium-base alloys by exposure of the materials to liquid lithium that contained 3/5 at.% dissolved aluminum in sealed V and V-20 wt.% Ti capsules at temperatures between 775 and 880 degrees C. After each test, the capsules were opened and the samples were examined by optical microscopy and scanning electron microscopy (SEM), and analyzed by electron-energy-dispersive spectroscopy (EDS) and X-ray diffraction. Hardness of the coating layers and bulk alloys was determined by microidentation techniques. The nature of the coatings, i.e., surface coverage, thickness, and composition, varied with exposure time and temperature, solute concentration in lithium, and alloy composition. Solute elements that yielded adherent coatings on various substrates can provide a means of developing in-situ electrical insulator coatings by reaction of the reactive layers with dissolved nitrogen in liquid lithium

Intergranular tellurium cracking of nickel-based alloys in molten Li, Be, Th, U/F salt mixture

Science.gov (United States)

Ignatiev, Victor; Surenkov, Alexander; Gnidoy, Ivan; Kulakov, Alexander; Uglov, Vadim; Vasiliev, Alexander; Presniakov, Mikhail

2013-09-01

In Russia, R&D on Molten Salt Reactor (MSR) are concentrated now on fast/intermediate spectrum concepts which were recognized as long term alternative to solid fueled fast reactors due to their attractive features: strong negative feedback coefficients, easy in-service inspection, and simplified fuel cycle. For high-temperature MSR corrosion of the metallic container alloy in primary circuit is the primary concern. Key problem receiving current attention include surface fissures in Ni-based alloys probably arising from fission product tellurium attack. This paper summarizes results of corrosion tests conducted recently to study effect of oxidation state in selected fuel salt on tellurium attack and to develop means of controlling tellurium cracking in the special Ni-based alloys recently developed for molten salt actinide recycler and tranforming (MOSART) system. Tellurium corrosion of Ni-based alloys was tested at temperatures up to 750 °C in stressed and unloaded conditions in molten LiF-BeF2 salt mixture fueled by about 20 mol% of ThF4 and 2 mol% of UF4 at different [U(IV)]/[U(III)] ratios: 0.7, 4, 20, 100 and 500. Following Ni-based alloys (in mass%): HN80М-VI (Mo—12, Cr—7.6, Nb—1.5), HN80МТY (Mo—13, Cr—6.8, Al—1.1, Ti—0.9), HN80МТW (Mo—9.4, Cr—7.0, Ti—1.7, W—5.5) and ЕМ-721 (W—25.2, Cr—5.7, Ti—0.17) were used for the study in the corrosion facility. If the redox state the fuel salt is characterized by uranium ratio [U(IV)]/[U(III)] uranium intermetallic compounds and alloys with nickel and molybdenum. This leads to spontaneous behavior of alloy formation processes on the specimens' surface and further diffusion of uranium deep into the metallic phase. As consequence of this films of intermetallic compounds and alloys of nickel, molybdenum, tungsten with uranium are formed on the alloys specimens' surface, and intergranular corrosion does not take place. In the fuel salt with [U(IV)]/[U(III)] = 4-20 the potentials of uranium

High Frequency Vibration Based Fatigue Testing of Developmental Alloys

Science.gov (United States)

Holycross, Casey M.; Srinivasan, Raghavan; George, Tommy J.; Tamirisakandala, Seshacharyulu; Russ, Stephan M.

Many fatigue test methods have been previously developed to rapidly evaluate fatigue behavior. This increased test speed can come at some expense, since these methods may require non-standard specimen geometry or increased facility and equipment capability. One such method, developed by George et al, involves a base-excited plate specimen driven into a high frequency bending resonant mode. This resonant mode is of sufficient frequency (typically 1200 to 1700 Hertz) to accumulate 107 cycles in a few hours. One of the main limitations of this test method is that fatigue cracking is almost certainly guaranteed to be surface initiated at regions of high stress. This brings into question the validity of the fatigue test results, as compared to more traditional uniaxial, smooth-bar testing, since high stresses are subjecting only a small volume to fatigue damage. This limitation also brings into question the suitability of this method to screen developmental alloys, should their initiation life be governed by subsurface flaws. However, if applicable, the rapid generation of fatigue data using this method would facilitate faster design iterations, identifying more quickly, material and manufacturing process deficiencies. The developmental alloy used in this study was a powder metallurgy boron-modified Ti-6Al-4V, a new alloy currently being considered for gas turbine engine fan blades. Plate specimens were subjected to fully reversed bending fatigue. Results are compared with existing data from commercially available Ti-6Al-4V using both vibration based and more traditional fatigue test methods.

Efficacy and toxicity of Samarium-153-EDTMP locally produced in the treatment of painful skeletal metastases

International Nuclear Information System (INIS)

Olea, E.; Quintana, J.C.; Nagel, J.; Arenas, L.; Tomicic, M.; Gil, M.C.; Araya, G.

2001-01-01

Samarium-153 emits medium-energy beta particles an a gamma photon with a physical half-life of 46,3 hours. When chelated to ethylenediaminetetramethylenephosphonic acid (EDTMP), it is remarkably stable in vitro and in vivo. In this study we administered randomly 0,5 and 1,0 mCi/Kg body weight (two groups), to 30 patients with painful metastatic bone cancer. Slight and spontaneously reversible myelotoxicity was observed. A bigger leukocyte and platelet suppression was obtained with 1,0 mCi/kg than 0,5 mCi/Kg dose. Pain palliation was obtained in 66% of the treated patients. Our preliminary results indicate that 153 Sm-EDTMP is a promising radiotherapeutic agent for palliative treatment of metastatic bone cancer pain where a reactor is available and at a very affordable cost. (author)

Room-Temperature Deformation and Martensitic Transformation of Two Co-Cr-Based Alloys

Science.gov (United States)

Cai, S.; Schaffer, J. E.; Huang, D.; Gao, J.; Ren, Y.

2018-05-01

Deformation of two Co-Cr alloys was studied by in situ synchrotron X-ray diffraction. Both alloys show stress-induced martensite transformation, which is affected by phase stabilities and transformation strains. Crystal structure of WC in Co-20Cr-15W-10Ni is identified. Compared with other phases present, it is elastically isotropic, exhibits high strength, and can elastically withstand strains exceeding 1 pct. Texture change during phase transformation is explained based on the crystal orientation relationship between γ- and ɛ-phases.

The electrochemical behaviour of various non-precious Ni and Co based alloys in artificial saliva

Directory of Open Access Journals (Sweden)

Mareci D.

2005-07-01

Full Text Available Five non-precious Ni-Co based alloys were analyzed with respect to their corrosion behaviour. The correlation between the amount of the elements Cr, Mo, V and the corrosion behaviour, expressed by the PREN (pitting resistance equivalent number index in the case of the allied steels, was extended for Ni-Cr and Co-Cr dental alloys characterization. Open circuit potential, corrosion current densities, as a measure of the corrosion rate, and main parameters of the corrosion process were evaluated from linear and cyclic polarization curves, for five Ni-Cr or Co-Cr alloys in an Afnor type artificial saliva. The maintenance times of the alloy in the corrosive medium influence the corrosion rate; the corrosion current values decrease with the maintenance time due to their passivation in solution. The microscopic analysis of the alloy surfaces shows that this passivation in solution does not modify the corrosion type. The alloys with PREN 32.9 are susceptible of localized corrosion.

Fabrication of samarium strontium aluminate ceramic and deposition of thermal barrier coatings by air plasma spray process

Directory of Open Access Journals (Sweden)

Baskaran T

2018-01-01

Full Text Available Thermal barrier coatings (TBC with the metallic NiCrAlY bond coat are often used in many aircraft engines to protect superalloy components from high-temperature corrosion thereby to improve the life of gas turbine components. The search for new TBC material has been intensified in recent years due to lack of thermo-physical properties of conventionally used Yttria stabilized Zirconia (YSZ TBCs. Recently, the rare earth containing Samarium Strontium Aluminate (SSA based ceramic was proposed as a new TBC material due to its matching thermo-physical properties with the substrate. The present work focused on the synthesis of SSA ceramics for TBCs application and its coatings development on Ni-based superalloy Inconel 718 substrate by air plasma spray process. The X-ray photoelectron spectroscopy (XPS result confirmed the formation of single phase SSA ceramic after synthesis. The surface morphology of SSA TBCs is mainly composed of melted splats, semi and un-melted particles. The cross-sectional SEM micrographs did not show any spallation at the interface which indicated good mechanical interlocking between the bond coat and ceramic top coat. The Young’s modulus and hardness of SSA TBCs were found to be 80 and 6.1 GPa, respectively. The load-depth curve of SSA TBC showed good elastic recovery about 47 %.

Experimental Studies on Al (5.7% Zn) Alloy based Hybrid MMC

Science.gov (United States)

Shivaprakash, Y. M.; Ramu, H. C.; Chiranjivee; Kumar, Roushan; Kumar, Deepak

2018-02-01

In this investigation, an attempt is made to disperse SiC (20-25 microns) and Gr (15-20 microns) in the aluminium alloy having Zn, Mg and coper as major alloying elements. The composite is further subjected to mechanical testing to determine various properties like hardness, tensile strength and wear resistance. The alloy and composite samples were tested in the un heat treated conditions. All the tests were done at the laboratory conditions as per ASTM standards. The Pin-On-Disc tribometer is used to test the two-body abrasive sliding wear behaviour in dry conditions. The wear pattern is analysed by the optical images of worn surface taken in an inverted metallurgical microscope. The calculated density is found to be reducing as the SiC and Gr quantity is increased in the base alloy. The as cast Al alloy was found to be having highest hardness. The introduction of SiC tend to increase the hardness and UTS, since Gr is also introduced simultaneously which tends to reduce the hardness and UTS of composite. The composite having highest quantity of Gr showed superior wear resistance which is mainly because the Gr particulates provide an inbuilt lubricating properties to composite. The analysis of images of worn surface showed the abrasive and delamination pattern of wear. The composites developed in the present work can be used in the automobile and aerospace parts that are light in weight and require self-lubricating properties to enhance the wear resistance.