WorldWideScience

Sample records for alloy system materials

  1. Alloy catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel alloy catalyst material for use in the synthesis of hydrogen peroxide from oxygen and hydrogen, or from oxygen and water. The present invention also relates to a cathode and an electrochemical cell comprising the novel catalyst material, and the process use...... of the novel catalyst material for synthesising hydrogen peroxide from oxygen and hydrogen, or from oxygen and water....

  2. Wettability in the liquid Cu-Ag alloy – fireproof material – gas phase system

    Directory of Open Access Journals (Sweden)

    G. Siwiec

    2013-07-01

    Full Text Available In the present paper, results of wettability studies on the liquid metal – fireproof material – gas phase system using copper and Cu-Ag alloys as well as typical fireproof materials, i.e. aluminium oxide, magnesium oxide and graphite, are presented. Contact angle measurements were conducted at 1 373–1 573 K by means of a high-temperature microscope coupled with a camera and a computer equipped with a program for recording and analysing images. For the measurements, the sessile drop method was used.

  3. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R. P. Martukanitz and S. Babu

    2007-05-03

    precipitation of titanium carbonitrides during laser surface alloying provided there was sufficient amount of dissolved titanium, carbon, and nitrogen in the liquid steel. This was confirmed experimentally by using a powder mixture of 431-martensitic steel, titanium carbide powder, and nitrogen shielding, during laser deposition to produce deposits exhibiting relatively high hardness (average surface hardness of 724 HV). The same approach was extended to direct diode laser processing and similar microstructures were attained. The above analysis was extended to develop an in-situ precipitation of Ti(CN) during laser deposition. The Ti addition was achieving by mixing the 431 martensitic steel powders with ferro-titanium. The dissolution of nitrogen was achieved by using 100% nitrogen shielding gas, which was indicated by thermodynamic analysis. Demonstrations were also conducted utilizing the tools developed during the program and resulted in several viable composite coating systems being identified. This included the use of TiC and ferro-titanium in martensitic-grade stainless steel matrix material with and without the use of active N2 shielding gas, WC hard particles in a martensitic-grade stainless steel matrix material, WC and BN in a nickel-based matrix material, and WC in highly alloyed iron-based matrix. Although these demonstrations indicated the potential of forming composite coatings, in certain instances, the intended industrial applications involved unique requirements, such as coating of internal surfaces, which hindered the full development of the improved coating technology. However, it is believed that the addition of common hard particles, such as WC or TiC, to matrix material representing martensitic grades of stainless steel offer opportunities for improved performance at relatively low material cost.

  4. Mechanical alloying in immiscible alloy systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In recent years, mechanical alloying (MA) of immiscible alloy systems characterized by positive heat of mixing has been extensively investigated. The present article reviews the latest progress in MA of immiscible alloy systems including the mechanisms of non-equilibrium phase transformation and metastable phase formation of the MA-driven supersaturated solid solutions, amorphous phases and nanophase composites as well as their mechanical and physical properties related to those metastable phases.

  5. Materials data handbook: Aluminum alloy 2219

    Science.gov (United States)

    Muraca, R. F.; Whittick, J. S.

    1972-01-01

    A summary of the materials property information for aluminum 2219 alloy is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and joining techniques is developed.

  6. A Study of the effect of gamma radiation on some alloy materials for use as dosimetry systems and its applications

    International Nuclear Information System (INIS)

    Alloys are metallic materials consisting of two or more elements combined in such a way that they cannot be readily separated by physical means. More than 90% of metals used are in the form of alloys. Alloys can be divided into two types: ferrous and non- ferrous. In metallurgy, a nonferrous metal is any metal that is not ferrous, including alloys, that does not contain iron in appreciable amounts. Groups of inorganic glassy materials which always contain one or more of the chalcogen elements S, Se or Te, in conjunction with more electropositive elements as As, Sb and Bi, are recognized as chalcogenide glasses but Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements, for example ferrotitanium alloy. Chalcogenide glasses are generally less robust, more weakly bonded materials than oxide glasses. Glasses were prepared from Ge, Se, As and Te elements with purity 99.999%.These glasses are reactive at high temperature with oxygen. Therefore, synthesis was accomplished in evacuated clean silica tubes. The tubes were washed by distilled water, and then dried in a furnace whose temperature was about 100 degree C. The weighted materials were introduced into the cleaned silica tubes and then evacuated to about 10-4 torr and sealed. The sealed tubes were placed inside the furnace and the temperature of the furnace was raised gradually up to 900 degree C within 1 hour and kept constant for 10 hours. Moreover, shaking of the constituent materials inside the tube in the furnace was necessary for realizing the homogeneity of the composition. After synthesis, the tube was quenched into ice water. The glassy ingots could be obtained by drastic quenching. Then materials were removed from the tubes and kept in dry atmosphere. Thin films of the selected compositions were prepared by thermal evaporation technique under vacuum 10-4 torr with constant thickness 100 nm. Ferrotitanium alloy is prepared by the reduction of rutile and ilmenite ores

  7. Mechanical alloying in the Fe-Cu system

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Gente, C.; Bormann, R.

    1998-01-01

    in the Fe-Cu system is; (3) where the positive energy is stored in the alloys; (4) what the decomposition process of the supersaturated alloys is; and (5) what type of magnetic properties the new materials have. The elucidation of these problems will shed light on the understanding of the mechanisms...... for the preparation of materials under highly non-equilibrium conditions in systems with positive heats of mixing by mechanical alloying....

  8. Computational Materials Program for Alloy Design

    Science.gov (United States)

    Bozzolo, Guillermo

    2005-01-01

    The research program sponsored by this grant, "Computational Materials Program for Alloy Design", covers a period of time of enormous change in the emerging field of computational materials science. The computational materials program started with the development of the BFS method for alloys, a quantum approximate method for atomistic analysis of alloys specifically tailored to effectively deal with the current challenges in the area of atomistic modeling and to support modern experimental programs. During the grant period, the program benefited from steady growth which, as detailed below, far exceeds its original set of goals and objectives. Not surprisingly, by the end of this grant, the methodology and the computational materials program became an established force in the materials communitiy, with substantial impact in several areas. Major achievements during the duration of the grant include the completion of a Level 1 Milestone for the HITEMP program at NASA Glenn, consisting of the planning, development and organization of an international conference held at the Ohio Aerospace Institute in August of 2002, finalizing a period of rapid insertion of the methodology in the research community worlwide. The conference, attended by citizens of 17 countries representing various fields of the research community, resulted in a special issue of the leading journal in the area of applied surface science. Another element of the Level 1 Milestone was the presentation of the first version of the Alloy Design Workbench software package, currently known as "adwTools". This software package constitutes the first PC-based piece of software for atomistic simulations for both solid alloys and surfaces in the market.Dissemination of results and insertion in the materials community worldwide was a primary focus during this period. As a result, the P.I. was responsible for presenting 37 contributed talks, 19 invited talks, and publishing 71 articles in peer-reviewed journals, as

  9. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael;

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  10. Hydrogen storage systems from waste Mg alloys

    Science.gov (United States)

    Pistidda, C.; Bergemann, N.; Wurr, J.; Rzeszutek, A.; Møller, K. T.; Hansen, B. R. S.; Garroni, S.; Horstmann, C.; Milanese, C.; Girella, A.; Metz, O.; Taube, K.; Jensen, T. R.; Thomas, D.; Liermann, H. P.; Klassen, T.; Dornheim, M.

    2014-12-01

    The production cost of materials for hydrogen storage is one of the major issues to be addressed in order to consider them suitable for large scale applications. In the last decades several authors reported on the hydrogen sorption properties of Mg and Mg-based systems. In this work magnesium industrial wastes of AZ91 alloy and Mg-10 wt.% Gd alloy are used for the production of hydrogen storage materials. The hydrogen sorption properties of the alloys were investigated by means of volumetric technique, in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and calorimetric methods. The measured reversible hydrogen storage capacity for the alloys AZ91 and Mg-10 wt.% Gd are 4.2 and 5.8 wt.%, respectively. For the Mg-10 wt.% Gd alloy, the hydrogenated product was also successfully used as starting reactant for the synthesis of Mg(NH2)2 and as MgH2 substitute in the Reactive Hydride Composite (RHC) 2LiBH4 + MgH2. The results of this work demonstrate the concrete possibility to use Mg alloy wastes for hydrogen storage purposes.

  11. High-entropy alloys as high-temperature thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Shafeie, Samrand [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Guo, Sheng, E-mail: sheng.guo@chalmers.se [Surface and Microstructure Engineering Group, Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Hu, Qiang [Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang 330029 (China); Fahlquist, Henrik [Bruker AXS Nordic AB, 17067 Solna (Sweden); Erhart, Paul [Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg (Sweden); Palmqvist, Anders, E-mail: anders.palmqvist@chalmers.se [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg (Sweden)

    2015-11-14

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  12. High-entropy alloys as high-temperature thermoelectric materials

    Science.gov (United States)

    Shafeie, Samrand; Guo, Sheng; Hu, Qiang; Fahlquist, Henrik; Erhart, Paul; Palmqvist, Anders

    2015-11-01

    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials.

  13. Influence of alloy ingredients on mechanical properties of ternary boride hard alloy clad materials

    Institute of Scientific and Technical Information of China (English)

    LIU Fu-tian; SONG Shi-xue; YANG Jun-ru; HUANG Wei-ling; HUANG Chuan-zhen; CHENG Xin; LI Zhao-qian

    2004-01-01

    Using Mo, B-Fe alloy and Fe powders as raw materials, and adding C, Cr and Ni ingredients, respectively, or C, Cr and Ni mixed powders, ternary boride hard alloy clad materials was prepared on Q235 steel substrate by means of in-situ reaction and vacuum liquid phase sintering technology. The influence of alloy ingredients on the mechanical properties of ternary boride hard alloy clad materials was investigated. The results indicate that a mixture of 0.8% C, 5% Cr and 2% Ni ingredients gives a ternary boride hard alloy clad material with optimal mechanical properties, such as high transverse rupture strength, high hardness and good wear resistance.

  14. Developing of an expert system for nonferrous alloy design

    Institute of Scientific and Technical Information of China (English)

    李义兵; 何红波; 周继承; 李斌

    2004-01-01

    Expert systems have been used widely in the predictions and design of alloy systems. But the expert systems are based on the macroscopic models that have no physical meanings. Microscopic molecular dynamics is also a standard computational technique used in materials science. An approach is presented to the design system of nonferrous alloy that integrates the molecular dynamical simulation together with an expert system. The knowledge base in the expert system is able to predict nonferrous alloy properties by using machine learning technology. The architecture of the system is presented.

  15. 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.

  16. PERSPECTIVES OF MOLIBDENUM CONTAINING MATERIALS APPLICATION FOR ALLOYING OF IRONCARBON ALLOYS DURING MANUFACTURING OF CRITICAL CASTINGS

    Directory of Open Access Journals (Sweden)

    A. G. Slutsky

    2015-01-01

    Full Text Available Motor is one of most important part of automobile determine its economical effectiveness of usage. On the other hand, sleeves, pistons and rings are crucible parts as they determine the service life of a motor. These parts are producing in big scale – dozens of millions pieces. Increase of cylinder sleeves physical-mechanical properties results in prolongation of motor service life and improvement of motor’s characteristics. Nowadays low alloyed cast irons with perlite structure are used to manufacture motor’s sleeves. For alloying purposes such traditional elements as Cr, Ni, Cu, and V are applied. But it is interesting to use molybdenum for cast iron alloying. It is known that alloying of alloys allows considerable increasing of consumption properties of castings. But in spite of advantages of alloys alloying the increase of molybdenum containing iron-carbon alloys production is restricted by economical reasons – high cost of alloying additions. Expenditures on alloying additions can be reduced by the application cheap secondary alloys in the charge. So, the present paper is devoted to investigation of alloying peculiarities during the treatment of ferrous alloys with molybdenum applying different initial materials.

  17. Equiatomic quaternary Heusler alloys: A material perspective for spintronic applications

    Science.gov (United States)

    Bainsla, Lakhan; Suresh, K. G.

    2016-09-01

    agreement with those estimated using the Slater-Pauling rule in most of the cases. Electrical resistivity and Hall measurements are being used to distinguish between SGS and HMF nature in detail. The current spin polarization value, P = 0.70 ± 0.01, for CoFeMnGe is found to be highest among the EQHAs. CoFeMnSi and CoFeCrGa are found to show SGS behavior with high Curie temperatures, thus making them suitable substitutes for diluted magnetic semiconductors. CoRuFeSi is found to have the highest TC among EQHAs. Theoretical prediction of magnetic properties on the basis of electronic structure calculations has also been reported in a few systems, which are also discussed in this review. Thus, this review presents a consolidated picture of the magnetic and spintronic properties of this important, but relatively new class of Heusler alloys. It is expected that this will stimulate further interest in these alloys, thereby paving the way for the identification of more HMF and SGS materials. As a result of this, it is expected that more efficient spintronic devices using these alloys would emerge in the near future.

  18. Shape memory alloys: New materials for future engineering

    Science.gov (United States)

    Hornbogen, E.

    1988-01-01

    Shape memory is a new material property. An alloy which experiences relative severe plastic deformation resumes its original shape again after heating by 10 to 100 C. Besides simple shape memory, in similar alloys there is the second effect where the change in shape is caused exclusively by little temperature change. In pseudo-elasticity, the alloy exhibits a rubber-like behavior, i.e., large, reversible deformation at little change in tension. Beta Cu and beta NiTi alloys have been used in practice. The probability is that soon alloys based on Fe will become available. Recently increasing applications for this alloy were found in various areas of technology, even medical technology. A review with 24 references is given, including properties, production, applications and fundamental principles of the shape memory effect.

  19. Switchable Shape Memory Alloys (SMA) Thermal Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Shape memory alloys applies to a group of materials that demonstrate the ability to return to some previously defined shape when subjected to the appropriate...

  20. Complex metallic alloys as new materials for additive manufacturing

    International Nuclear Information System (INIS)

    Additive manufacturing processes allow freeform fabrication of the physical representation of a three-dimensional computer-aided design (CAD) data model. This area has been expanding rapidly over the last 20 years. It includes several techniques such as selective laser sintering and stereolithography. The range of materials used today is quite restricted while there is a real demand for manufacturing lighter functional parts or parts with improved functional properties. In this article, we summarize recent work performed in this field, introducing new composite materials containing complex metallic alloys. These are mainly Al-based quasicrystalline alloys whose properties differ from those of conventional alloys. The use of these materials allows us to produce light-weight parts consisting of either metal–matrix composites or of polymer–matrix composites with improved properties. Functional parts using these alloys are now commercialized. (review)

  1. Investigations of mechanically alloyed nanocrystalline materials by microacoustic techniques

    Science.gov (United States)

    Dubief, P.; Hunsinger, J. J.; Gaffet, E.

    1996-09-01

    The purpose of this work is to determine whether yes or no, there is a difference between the physico-chemical properties of the nanocrystalline and the microcrystalline materials. This paper deals with the acoustical behavior of nanocrystalline materials which were prepared by ball- milling and mechanical alloying. Based on two specific techniques (acoustic microinterferometry and acoustic microechography), some of the mechanical properties (elastic ones) may be determined, related to a materials volume of about a few micrometers 3 (for the high frequency 600 MHz apparatus). Thus the mechanically alloyed powders (typically 200 micrometers in diameter), behave as massive materials in this range of frequency. The measurements are directly obtained on the grains and do not take into account the voids induced by further sinthering process. The result of such a micromechanical approach will be given for pure ball-milled elements (Fe) and for the supersaturated solid phase Fe(Si) obtained by mechanical alloying.

  2. Design of multi materials combining crystalline and amorphous metallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Volland, A.; Ragani, J.; Liu, Y.; Gravier, S.; Suery, M. [Grenoble University/CNRS, SIMAP Laboratory, Grenoble INP/UJF, 38402 Saint-Martin d' Heres (France); Blandin, J.J., E-mail: jean-jacques.blandin@simap.grenoble-inp.fr [Grenoble University/CNRS, SIMAP Laboratory, Grenoble INP/UJF, 38402 Saint-Martin d' Heres (France)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Elaboration of multi materials associating metallic glasses and conventional crystalline alloys by co-deformation performed at temperatures close to the glass transition temperature of the metallic glasses. Black-Right-Pointing-Pointer Elaboration of filamentary metal matrix composites with a core in metallic glass by co extrusion. Black-Right-Pointing-Pointer Sandwich structures produced by co-pressing. Black-Right-Pointing-Pointer Detection of atomic diffusion from the glass to the crystalline alloys during the processes. Black-Right-Pointing-Pointer Good interfaces between the metallic glasses and the crystalline alloys, as confirmed by mechanical characterisation. - Abstract: Multi materials, associating zirconium based bulk metallic glasses and crystalline metallic alloys like magnesium alloys or copper are elaborated by co-deformation processing performed in the supercooled liquid regions (SLR) of the bulk metallic glasses. Two processes are investigated: co-extrusion and co-pressing. In the first case, filamentary composites with various designs can be produced whereas in the second case sandwich structures are obtained. The experimental window (temperature, time) in which processing can be carried out is directly related to the crystallisation resistance of the glass which requires getting information about the crystallisation conditions in the selected metallic glasses. Thermoforming windows are identified for the studied BMGs by thermal analysis and compression tests in their SLR. The mechanical properties of the produced multi materials are investigated thanks to specifically developed mechanical devices and the interfaces between the amorphous and the crystalline alloys are characterised.

  3. Tungsten alloy research at the US Army Materials Technology Laboratory

    International Nuclear Information System (INIS)

    This paper reports that recent research into tungsten heavy alloys at the U. S. Army Materials Technology Laboratory (MTL) has explored many areas of processing and process development. The recrystallization and respheroidization of tungsten grains in a heavily cold worked heavy alloy has been examined and resulted in the identification of a method of grain refinement. Another area of investigation has been lightly cold worked. It was determined that it was possible to increase the strength and hardness of the tungsten grains by proper hat treatment. MTL has been involved in the Army's small business innovative research (SBIR) program and several programs have been funded. Included among these are a method of coating the tungsten powders with the alloying elements and the development of techniques of powder injection molding of heavy alloys

  4. Forming analysis and application for aluminum-alloy material

    Institute of Scientific and Technical Information of China (English)

    Wei Yuansheng

    2012-01-01

    The increase in car ownership brought about by energy shortages, and environmental crises became more acute. The most effective way to achieve energy saving and emission reduction of car is to improve engine efficiency. In addition to that, lightweight body is the key. Aluminum, magnesium alloy as significant materials of lightweight, and the application amount in the car body is a significant upward trend. However, there is high cost of material, with im- mature applied technology and a series of bottleneck problems. All of them affect general application of lightweight mate- rials. This paper focuses on forming process issues for aluminum, magnesium alloy and the solutions to achieve.

  5. Applicability of existing magnesium alloys as biomedical implant materials

    NARCIS (Netherlands)

    Erinc, M.; Sillekens, W.H.; Mannens, R.G.T.M.; Werkhoven, R.J.

    2009-01-01

    Being biocompatible and biodegradable, magnesium alloys are considered as the new generation biomedical implant materials, such as for stents, bone fixtures, plates and screws. A major drawback is the poor chemical stability of metallic magnesium; it corrodes at a pace that is too high for most pros

  6. Diamond-cBN alloy: A universal cutting material

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pei [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); High Pressure Science and Engineering Center and Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States); He, Duanwei, E-mail: duanweihe@scu.edu.cn; Kou, Zili; Li, Yong; Hu, Qiwei; Xu, Chao; Lei, Li; Wang, Qiming [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Wang, Liping; Zhao, Yusheng [High Pressure Science and Engineering Center and Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States); Xiong, Lun; Liu, Jing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-09-07

    Diamond and cubic boron nitride (cBN) as conventional superhard materials have found widespread industrial applications, but both have inherent limitations. Diamond is not suitable for high-speed cutting of ferrous materials due to its poor chemical inertness, while cBN is only about half as hard as diamond. Because of their affinity in structural lattices and covalent bonding character, diamond and cBN could form alloys that can potentially fill the performance gap. However, the idea has never been demonstrated because samples obtained in the previous studies were too small to be tested for their practical performance. Here, we report the synthesis and characterization of transparent bulk diamond-cBN alloy compacts whose diameters (3 mm) are sufficiently large for them to be processed into cutting tools. The testing results show that the diamond-cBN alloy has superior chemical inertness over polycrystalline diamond and higher hardness than single crystal cBN. High-speed cutting tests on hardened steel and granite suggest that diamond-cBN alloy is indeed a universal cutting material.

  7. Fundamentals of radiation materials science metals and alloys

    CERN Document Server

    Was, Gary S

    2017-01-01

    The revised second edition of this established text offers readers a significantly expanded introduction to the effects of radiation on metals and alloys. It describes the various processes that occur when energetic particles strike a solid, inducing changes to the physical and mechanical properties of the material. Specifically it covers particle interaction with the metals and alloys used in nuclear reactor cores and hence subject to intense radiation fields. It describes the basics of particle-atom interaction for a range of particle types, the amount and spatial extent of the resulting radiation damage, the physical effects of irradiation and the changes in mechanical behavior of irradiated metals and alloys. Updated throughout, some major enhancements for the new edition include improved treatment of low- and intermediate-energy elastic collisions and stopping power, expanded sections on molecular dynamics and kinetic Monte Carlo methodologies describing collision cascade evolution, new treatment of t...

  8. VAMAS tests of structural materials on aluminum alloy and composite material at cryogenic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, T. [National Research Institute for Metals, Tsukuba, Ibaraki (Japan); Evans, D. [Rutherford Appleton Lab., Chilton (United Kingdom)

    1997-06-01

    A Technical Working Area 17, cryogenic structural materials, has been organized in the Versailles Project on Advanced Materials and Standards (VAMAS) to promote the prestandardization program on material properties tests of glass fiber reinforced polymer (GFRP) composite materials and alloys at liquid helium temperature. A series of international interlaboratory comparisons of both tensile and fracture toughness tests for aluminum alloy 2219 and compression and shear tests for composite material G-10CR were performed. Nine research institutes from seven nations have participated in this project. The results prove that there are few problems in cryogenic tensile tests for alloy materials. In compression and shear tests, the amount of data scatter was identified and further experiments are planned. This paper presents the program details and interim results of round robin tests.

  9. VAMAS tests of structural materials on aluminum alloy and composite material at cryogenic temperatures

    International Nuclear Information System (INIS)

    A Technical Working Area 17, cryogenic structural materials, has been organized in the Versailles Project on Advanced Materials and Standards (VAMAS) to promote the prestandardization program on material properties tests of glass fiber reinforced polymer (GFRP) composite materials and alloys at liquid helium temperature. A series of international interlaboratory comparisons of both tensile and fracture toughness tests for aluminum alloy 2219 and compression and shear tests for composite material G-10CR were performed. Nine research institutes from seven nations have participated in this project. The results prove that there are few problems in cryogenic tensile tests for alloy materials. In compression and shear tests, the amount of data scatter was identified and further experiments are planned. This paper presents the program details and interim results of round robin tests

  10. A study of surface tension driven segregation in monotectic alloy systems

    Science.gov (United States)

    Andrews, J. Barry; Andrews, Rosalia N.; Gowens, Terrell F.

    1988-01-01

    The compatibilities of various monotectic alloy systems with several different crucible materials were evaluated. The study was carried out using small candidate alloy samples of compositions that produced fifty volume percent of each liquid phase at the monotectic temperature. Compatibility was based on the evaluation of the wetting tendency of the two immiscible phases with the crucible material in a one-g solidified sample. Three types of wetting phenomena were observed during the evaluation. Type 1 indicates an alloy-crucible combination where the L2 phase preferentially wets the crucible material. Since L2 is usually the minority phase in desirable alloys, this material combination would be difficult to process and is therefore considered incompatible. Type 2 behavior indicates an alloy-crucible combination where the L1 phase preferentially wets the crucible material. This type of combination is considered compatible since surface tension effects should aid in processing the alloy to a useful form. Type 3 indicates any combination that leads to major reactions between the alloy and crucible material, gas entrapment, or separation of the metal from the crucible wall. Additional compatibility evaluations would have to be carried out on combinations of this category. The five alloy systems studied included aluminum-bismuth, copper-lead, aluminum-indium, aluminum-lead and cadmium-gallium. The systems were combined with crucibles of alumina, boron nitride, mullite, quartz, silicon carbide and zirconia.

  11. Advanced gas cooled nuclear reactor materials evaluation and development program. Selection of candidate alloys. Vol. 1. Advanced gas cooled reactor systems definition

    Energy Technology Data Exchange (ETDEWEB)

    Marvin, M.D.

    1978-10-31

    Candidate alloys for a Very High Temperature Reactor (VHTR) Nuclear Process Heal (NPH) and Direct Cycle Helium Turbine (DCHT) applications in terms of the effect of the primary coolant exposure and thermal exposure were evaluated. (FS)

  12. NASA-UVa light aerospace alloy and structures technology program supplement: Aluminum-based materials for high speed aircraft

    Science.gov (United States)

    Starke, E. A., Jr. (Editor)

    1995-01-01

    This report on the NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from July 1, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) Ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) Powder metallurgy 2XXX alloys, (3) Rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) Discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  13. A Study on the Material Reliability of a Ni Alloy Electrodeposition

    International Nuclear Information System (INIS)

    Due to the occasional occurrences of a localized corrosion such as a SCC and pitting in steam generator tubing(Alloy 600), the degraded tube is removed from service and fixed by a plugging leading to a significant economical loss. Otherwise, a degraded steam generator tube is repaired for re-use. Apart from the typical sleeving method by introducing welding and mechanical expansions which causes a residual stress in the parent tube, an electrodeposition inside a tube does not induce a parent tube deformation and hence a significant residual stress. For a successful electrodeposition inside a tube, many processes should be developed. Among these processes, an anode to be installed inside a tube, a degreasing condition to remove any dirt and grease, an activation condition for a surface oxide elimination, a strike layer forming condition to be adhered tightly between the electroforming layer and the parent tube and a condition for an electroforming layer should be established. Through a combination of these various process parameters, the desired material properties can be accomplished. For an application in a plant, it should be noted that a material reliability of the electrodeposit concerned with a variation of a material property as a function of the electrodeposit position in the vertical direction of a tube is also very important. It is natural that a Ni alloy electrodeposition is selected as a proper electrodeposition system because Alloy 600 is mainly composed of nickel and a nickel electroplating has been widely studied to improve a corrosion resistance, and the mechanical and magnetic properties. Moreover, a Ni alloy electrodeposition process can be used for a PWSCC mitigation of various components including a steam generator tube because a Ni alloy electrodeposit shows an excellent SCC resistance. This work is related to an anode development for an electrodeposition inside a tube and a variation of material properties of the Ni alloy electrodeposits formed

  14. Arc welding of high strength aluminium alloys for armour systems applications

    OpenAIRE

    Pickin, Craig Graeme

    2011-01-01

    The ternary Al-Cu-Mg system 2xxx series aluminium alloys were examined as construction materials for armour system applications based upon comparable ballistic properties to the currently employed Al-7xxx series alloys. Utilising MIG welding solidification cracking was evident when welding constrained Al-2024 candidate base material using Al-2319 filler, the only available consumable wire for this series. A previously developed thermodynamic model suggested that an incompatible...

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

    International Nuclear Information System (INIS)

    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)

  16. Palladium-rare-earth metal alloys-advanced materials for hydrogen power engineering

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Hydrogen of no less than 99. 999 % (vol. fraction) purity is a principal power media of hydrogen power engineering. A single method for the preparation of high purity hydrogen consists in its separation from vapour-gas mixtures via the selective diffusion of hydrogen through a palladium membrane. The rate of hydrogen diffusion and the strength and stability during the operation in aggressive gases are important characteristics of palladium membranes. The increase in the strength, plasticity, and hydrogen-permeability of membrane alloys can be reached by alloying palladium with the formation of solid solutions.The formation of wide ranges of palladium-rare-earth metal (REM) solid solutions is an interesting feature of palladium. Earlier, we have shown that the alloying of Pd with REM substantially increases the rate of hydrogen diffusion and markedly increases the strength of palladium on retention of the adequate plasticity.In this work, we have studied alloys of the Pd-Y and Pd-Y-Me systems. It was shown that the following conditions should be satisfied to prepare high-quality alloys exhibiting high service properties: (1)the use of high-purity components (whose purity is no less than 99.95%, mass fraction), in particular,high-purity Y prepared by vacuum distillation, and (2) holding the reached purity for the final product.For this purpose, we suggested a cycle of manufacturing operations including the preparation of a vacuumtight foil of 50 (m thick as the final stage.The hydrogen-permeability of the alloys was measured at different temperatures and hydrogen pressures. The instability of operation of binary Pd-Y alloys w alloying the composition with a Ⅷ Group metal. For example, the alloy of the optimum composition Pd-8Y-Me in the annealed state exhibits the following mechanical properties: HV= 75 kg/mm2 , σu = 58 kg/mm2 , and δ= 20%. Its hydrogen-permeability (QH2) measured as a function of the temperature exceeds that of the Pd-23Ag alloy (that is widely

  17. Rare earth-Mg-Ni-based hydrogen storage alloys as negative electrode materials for Ni/MH batteries

    International Nuclear Information System (INIS)

    Research highlights: → State-of-the-art of new R-Mg-Ni-based hydrogen storage electrode alloys is reviewed. → Electrode performances of the R-Mg-Ni-based alloys depend strongly on the stoichiometric ratio, alloy components and microstructure. → Optimized alloy compositions contain mainly metallic elements of La, Mg, Ni, Co, Mn and Al. → Pulverization of particles and oxidation/corrosion of active components are responsible for the fast capacity degradation. → Low-Co or Co-free R-Mg-Ni-based electrode alloys should be developed. - Abstract: This review is devoted to new rare earth-Mg-Ni-based (R-Mg-Ni-based) hydrogen storage alloys that have been developed over the last decade as the most promising next generation negative electrode materials for high energy and high power Ni/MH batteries. Preparation techniques, structural characteristics, gas-solid reactions and electrochemical performances of this system alloy are systematically summarized and discussed. The improvement in electrochemical properties and their degradation mechanisms are covered in detail. Optimized alloy compositions with high discharge capacities, good electrochemical kinetics and reasonable cycle lives are described as well. For their practical applications in Ni/MH batteries, however, it is essential to develop an industrial-scale homogeneous preparation technique, and a low-cost R-Mg-Ni-based electrode alloy (low-Co or Co-free) with high discharge capacity, long cycle life and good kinetics.

  18. Material system for high temperature jet engine operation

    International Nuclear Information System (INIS)

    A materials system is presented which is adapted for use in jet engines operable at high temperature and at lower density than possible with nickel base superalloys. A range of niobium base alloys is combined with a range of protective metallic coatings to provide a material system which permits a wide variety of alloy properties and performance characteristics to be combined in structural components of jet engines

  19. Corrosion, Al containing corrosion barriers and mechanical properties of steels foreseen as structural materials in liquid lead alloy cooled nuclear systems

    International Nuclear Information System (INIS)

    A key problem in development of heavy liquid metal cooled nuclear energy and transmutation reactors is the corrosion of structural and fuel. Above 500 oC steels have to be protected by stable, thin oxide scales. A well understood measure is alloying of stable oxide formers into the surface. Two methods, alloying an Al layer into the steel surface using pulsed electron beams (GESA - gepulste Elektronenstrahlanlage) and coating the surface with an Al-alloy with subsequent GESA treatment are applied. In the range of 4-10 wt% Al on the surface a stable thin alumina scale is formed by Al diffusion to the surface and selective oxidation. The alumina scale grows only very slowly and prevents migration of oxygen into the steel as well as migration of steel components onto the surface. A number of corrosion experiments showed the good protective behaviour of Al scales in LBE with 10-6 wt% oxygen up to 650 oC and for exposure times up to 10,000 h. Furthermore the influence of parameters like stresses in the cladding wall, creep behaviour, different flow velocities of the LBE and changing temperatures and oxygen concentrations in LBE is discussed. This paper will provide an overview on the activities concerning Pb-PbBi corrosion and corrosion protection performed at the Institute of Pulsed Power and Microwave Technology (IHM) at the KIT.

  20. Material Fatigue Testing System

    Science.gov (United States)

    Gilley, P. J. (Inventor)

    1973-01-01

    A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading.

  1. Emerging smart materials systems

    Energy Technology Data Exchange (ETDEWEB)

    Strock, H.B. [Strock Technology Associates Inc., Holden, MA (United States)

    1996-04-01

    Smart materials systems are nonliving systems that integrate the functions of sensing, actuation, logic and control to respond adaptively to changes in their condition or the environment to which they are exposed, in a useful and usually repetitive manner. Smart materials possess both sensing and actuation capability. They can adaptively respond to changing stimuli, e.g., the variable darkening of photochromic glass or plastic on exposure to sunlight. Such passively smart materials behavior has relatively limited, although marketable, functionality.

  2. Advanced materials for space nuclear power systems

    Science.gov (United States)

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  3. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, modified alloy 800, and two sulfidation resistant alloys: HR160 and HR120. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700{degrees}C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925{degrees}C with good weldability and ductility.

  4. Unravelling the materials genome: Symmetry relationships in alloy properties

    Energy Technology Data Exchange (ETDEWEB)

    Toda-Caraballo, Isaac [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Galindo-Nava, Enrique I. [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Delft University of Technology, Mekelweg 2, Delft 2628 CD (Netherlands); Rivera-Díaz-del-Castillo, Pedro E.J., E-mail: pejr2@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2013-07-25

    Highlights: ► Research strategy for Accelerated Metallurgy project is outlined. ► Surprising symmetry among atomic, nanoscale and mechanical properties. ► Generalisation of Ashby diagrams via principal component analysis. ► Atomic-related properties can be described with linear regression. ► Mechanical properties modelled via Kocks–Mecking-type physical method. -- Abstract: Metals and alloys have been indispensable for technological progress, but only a fraction of the possible ternary systems (combinations of three elements) is known. Statistical inference methods combined with physical models are presented to discover new systems of enhanced properties. It is demonstrated that properties originating from atomic-level interactions can be described employing a linear regression analysis, but properties incorporating microstructural and thermal history effects require a balance between physical and statistical modelling. In spite of this, there is a remarkable degree of symmetry among all properties, and by employing a principal components analysis it is shown that ten properties essential to engineering can be described well in a three dimensional space. This will aid in the discovery of novel alloying systems.

  5. Unravelling the materials genome: Symmetry relationships in alloy properties

    International Nuclear Information System (INIS)

    Highlights: ► Research strategy for Accelerated Metallurgy project is outlined. ► Surprising symmetry among atomic, nanoscale and mechanical properties. ► Generalisation of Ashby diagrams via principal component analysis. ► Atomic-related properties can be described with linear regression. ► Mechanical properties modelled via Kocks–Mecking-type physical method. -- Abstract: Metals and alloys have been indispensable for technological progress, but only a fraction of the possible ternary systems (combinations of three elements) is known. Statistical inference methods combined with physical models are presented to discover new systems of enhanced properties. It is demonstrated that properties originating from atomic-level interactions can be described employing a linear regression analysis, but properties incorporating microstructural and thermal history effects require a balance between physical and statistical modelling. In spite of this, there is a remarkable degree of symmetry among all properties, and by employing a principal components analysis it is shown that ten properties essential to engineering can be described well in a three dimensional space. This will aid in the discovery of novel alloying systems

  6. Super-High Temperature Alloys and Composites from NbW-Cr Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shailendra Varma

    2008-12-31

    Nickel base superalloys must be replaced if the demand for the materials continues to rise for applications beyond 1000{sup o}C which is the upper limit for such alloys at this time. There are non-metallic materials available for such high temperature applications but they all present processing difficulties because of the lack of ductility. Metallic systems can present a chance to find materials with adequate room temperature ductility. Obviously the system must contain elements with high melting points. Nb has been chosen by many investigators which has a potential of being considered as a candidate if alloyed properly. This research is exploring the Nb-W-Cr system for the possible choice of alloys to be used as a high temperature material.

  7. Finishing Titanium Alloy Cutting Zone Analysis Via Multifunction Measuring System

    Science.gov (United States)

    Andrej, Czán; Michal, Šajgalík; Drbúl, Mário; Holubják, Jozef; Mrázik, Jozef; Babík, Ondrej; Zaušková, Lucia; Piešová, Marianna

    2015-12-01

    With the development of automotive, aerospace and biomedical industry, there is higher demand for exotic alloys, often based on titanium or nickel, though they are hard to machine. Therefore, it is essential to thoroughly understand their behavior during machining. Processes in the cutting zone of said materials are due to the complexity and dynamics defined by specific models. These include some deviations, thus it is essential to improve machining observation methodology, so exhibited errors and deviations are minimal or none. Based on the observations, multifunction measuring system has been designed, which allows simultaneous observation of characteristics such as e.g. cutting forces, deformations and thermal spread without uninterrupting machining process.

  8. Mapping Chemical Selection Pathways for Designing Multicomponent Alloys: an informatics framework for materials design

    Science.gov (United States)

    Srinivasan, Srikant; Broderick, Scott R.; Zhang, Ruifeng; Mishra, Amrita; Sinnott, Susan B.; Saxena, Surendra K.; Lebeau, James M.; Rajan, Krishna

    2015-12-01

    A data driven methodology is developed for tracking the collective influence of the multiple attributes of alloying elements on both thermodynamic and mechanical properties of metal alloys. Cobalt-based superalloys are used as a template to demonstrate the approach. By mapping the high dimensional nature of the systematics of elemental data embedded in the periodic table into the form of a network graph, one can guide targeted first principles calculations that identify the influence of specific elements on phase stability, crystal structure and elastic properties. This provides a fundamentally new means to rapidly identify new stable alloy chemistries with enhanced high temperature properties. The resulting visualization scheme exhibits the grouping and proximity of elements based on their impact on the properties of intermetallic alloys. Unlike the periodic table however, the distance between neighboring elements uncovers relationships in a complex high dimensional information space that would not have been easily seen otherwise. The predictions of the methodology are found to be consistent with reported experimental and theoretical studies. The informatics based methodology presented in this study can be generalized to a framework for data analysis and knowledge discovery that can be applied to many material systems and recreated for different design objectives.

  9. Investigation on low activated materials on the base of V-Ti-Cr alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Low activated materials on the base of vanadium are among the key materials for future fusion reactors. In the Russian Federation the long term National Program on the development of such vanadium alloys is under the way.

  10. Investigation on low activated materials on the base of V-Ti-Cr alloys

    Institute of Scientific and Technical Information of China (English)

    Potapenko; M.; Shikov; A.; Chernov; V.; Drobishev; V.; Gubkin; I.

    2005-01-01

    Low activated materials on the base of vanadium are among the key materials for future fusion reactors. In the Russian Federation the long term National Program on the development of such vanadium alloys is under the way.……

  11. Improved Damage Resistant Composite Materials Incorporating Shape Memory Alloys

    Science.gov (United States)

    Paine, Jeffrey S. N.; Rogers, Craig A.

    1996-01-01

    Metallic shape memory alloys (SMA) such as nitinol have unique shape recovery behavior and mechanical properties associated with a material phase change that have been used in a variety of sensing and actuation applications. Recent studies have shown that integrating nitinol-SMA actuators into composite materials increases the composite material's functionality. Hybrid composites of conventional graphite/epoxy or glass/epoxy and nitinol-SMA elements can perform functions in applications where monolithic composites perform inadequately. One such application is the use of hybrid composites to function both in load bearing and armor capacities. While monolithic composites with high strength-to-weight ratios function efficiently as loadbearing structures, because of their brittle nature, impact loading can cause significant catastrophic damage. Initial composite failure modes such as delamination and matrix cracking dissipate some impact energy, but when stress exceeds the composite's ultimate strength, fiber fracture and material perforation become dominant. One of the few methods that has been developed to reduce material perforation is hybridizing polymer matrix composites with tough kevlar or high modulus polyethynylene plies. The tough fibers increase the impact resistance and the stiffer and stronger graphite fibers carry the majority of the load. Similarly, by adding nitinol-SMA elements that absorb impact energy through the stress-induced martensitic phase transformation, the composites' impact perforation resistance can be greatly enhanced. The results of drop-weight and high velocity gas-gun impact testing of various composite materials will be presented. The results demonstrate that hybridizing composites with nitinol-SMA elements significantly increases perforation resistance compared to other traditional toughening elements. Inspection of the composite specimens at various stages of perforation by optical microscope illustrates the mechanisms by which

  12. Polyphase alloys as rechargeable electrodes in advanced battery systems

    Science.gov (United States)

    Huggins, Robert A.

    1987-01-01

    The rechargeability of electrochemical cells is often limited by negative electrode problems. These may include loss of capacity, increased impedance, macroscopic shape change, dendrite growth, or a tendency for filamentary or whisker growth. In principle, these problems can be reduced or eliminated by the use of alloys that undergo either displacement or insertion reactions at reactant species activities less than unity, rather than pure elements. The fundamental reasons for some of these problems with elemental electrodes, as well as the basic principles involved in the different behavior of alloys, are briefly discussed. More information is now available concerning the thermodynamic and kinetic properties of a number of alloys of potential interest for use as electrodes in elevated temperature lithium battery systems. Recent results have extended these results down to ambient temperatures, indicating that some such materials may be of interest for use with new low temperature molten salt electrolytes, or with organic solvent electrolytes. The all solid mixed conductor matrix concept is also reviewed.

  13. Structural alloys for superconducting magnets in fusion energy systems

    International Nuclear Information System (INIS)

    The behaviour of selected alloys for superconducting magnet structures in fusion energy systems is reviewed with emphasis on the following austenitic stainless steels (AISI grades 304, 310S and 316), nitrogen-strengthened austenitic stainless steels (types 304LN, 316LN and 21Cr-6Ni-9Mn) and aluminium alloys (grades 5083, 6061 and 2219). The mechanical and physical properties of the selected alloys at 4 K are reviewed. Welding, the properties of weldments, and other fabrication considerations are briefly discussed. The available information suggests that several commercial alloys have adequate properties at 4 K and sufficient fabrication characteristics for the large magnet structures needed for fusion energy systems. (orig.)

  14. Structural alloys for superconducting magnets in fusion energy systems

    International Nuclear Information System (INIS)

    The behavior of selected alloys for superconducting magnet structures in fusion energy systems is reviewed with emphasis on austenitic stainless steels (AISI grades 304, 310S, and 316), nitrogen-strengthened austenitic stainless steels (304LN, 316LN, and 21Cr-6Ni-9Mn) and aluminum alloys (5083, 6061, and 2219). The mechanical and physical properties of the selected alloys at 40K are reviewed. Welding, properties of weldments, and other fabrication considerations are briefly discussed. The available information suggests that several commercial alloys have adequate properties at 40K and sufficient fabrication characteristics for the large magnet structures needed for fusion energy systems

  15. Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Bernd; Sievers, Birte; Utzschneider, Sandra; Mueller, Peter; Jansson, Volkmar [Department of Orthopedic Surgery, Ludwig-Maximilians-University of Munich, Marchioninistrasse 15, 81377 Muenchen (Germany); Roessler, Sophie; Nies, Berthold [InnoTERE GmbH, Tatzberg 47, 01307 Dresden (Germany); Stephani, Guenter; Kieback, Bernd [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany); Quadbeck, Peter, E-mail: peter.quadbeck@ifam-dd.fraunhofer.de [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany)

    2011-12-15

    Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.

  16. Development of a new β Ti alloy with low modulus and favorable plasticity for implant material.

    Science.gov (United States)

    Liang, S X; Feng, X J; Yin, L X; Liu, X Y; Ma, M Z; Liu, R P

    2016-04-01

    One of the most important development directions of the Ti and its alloys is the applications in medical field. Development of new Ti alloys with low elastic modulus and/or favorable biocompatibility plays an important role for promoting its application in medical field. In this work, a new β Ti alloy (Ti-31Nb-6Zr-5Mo, wt.%) was designed for implant material using d-electron alloy design method. Microstructure and tensile properties of the designed alloy after hot rolling (HR) and solution followed by aging treatments (SA) were investigated. Results show that the designed alloy is composed of single β phase. However, microstructural analysis shows that the β phase in the designed alloy separates into Nb-rich and Nb-poor phase regions. The Nb-rich regions in HR specimen are typical elongated fiber texture, but are equiaxed particles with several micrometers in SA specimen. Tensile results show that the designed alloy has low Young's modulus of 44 GPa for HR specimen and 48 GPa for SA specimen which are very close to the extreme of Young's modulus of bulk titanium alloys. At the same time, the designed alloy has favorable plasticity in term of elongation of 26.7% for HR specimen and 20.6% for SA specimen, and appropriate tensile strength over 700 MPa. In short, the designed alloy has low elastic modulus close to that of bone and favorable plasticity and strength which can be a potential candidate for hard tissue replacements. PMID:26838858

  17. Transients in the composition of material sputtered from alloy targets

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, H.H.; Stenum, B.; Soerensen, T.; Whitlow, H.J. (Aarhus Univ. (Denmark). Inst. of Physics)

    1984-03-01

    Material sputtered with 20-320 keV Ar/sup +/ ions from the binary alloy CuPt, Ni/sub 5/Pt and NiPt has been collected sequentially on thin carbon foils. The composition of the collected material was analyzed by Rutherford backscattering to reveal transients in the composition of the sputtered flux. In the beginning Cu and Ni were preferentially ejected. These results, together with earlier data for AgAu and Cu/sub 3/Au, where Ag and Cu were preferentially ejected, show the lighter element to be preferentially emitted during the transient, but particularly the results for Cu/sub 3/Au and Ni/sub 5/Pd suggest that a native oxide layer may play a substantial role, although only for the case of Cu/sub 3/Au did such an oxide have a sufficient thickness to be revealed by Rutherford backscattering. Measurements have further been carried out for pure copper bombarded with 45 keV Bi/sup +/ ions. Here, the bismuth re-emission reaches a steady-state a factor of 10 faster than the copper yield, a fact which again may be related to oxygen-driven surface segregation. 39 refs.

  18. Tantalum-niobium-alloys as electrolyte capacitor materials

    Energy Technology Data Exchange (ETDEWEB)

    Chamdawalla, N.; Ettmayer, P.; Leuprecht, R.; Aschenbrenner, W.; Bildstein, H.

    1986-07-01

    The properties of Na-Nb-alloys with respect to their use in electrolytic foil condensers were examined by measuring the etching factor, the formability of Ta-Nb foils and the residual current of Ta-Nb alloy wires used for contact leads. Alloys with Nb contents up to 25 wt.-% can be used instead of unalloyed Ta without loss of quality. If the etching and forming procedures were optimized for different compositions, the use of alloys with up to 50 wt.-% Nb for capacitors might be feasible.

  19. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  20. High strength alloys

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  1. A comparison of thermoelectric phenomena in diverse alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Bruce

    1999-01-01

    The study of thermoelectric phenomena in solids provides a wealth of opportunity for exploration of the complex interrelationships between structure, processing, and properties of materials. As thermoelectricity implies some type of coupled thermal and electrical behavior, it is expected that a basic understanding of transport behavior in materials is the goal of such a study. However, transport properties such as electrical resistivity and thermal diffusivity cannot be fully understood and interpreted without first developing an understanding of the material's preparation and its underlying structure. It is the objective of this dissertation to critically examine a number of diverse systems in order to develop a broad perspective on how structure-processing-property relationships differ from system to system, and to discover the common parameters upon which any good thermoelectric material is based. The alloy systems examined in this work include silicon-germanium, zinc oxide, complex intermetallic compounds such as the half-Heusler MNiSn, where M = Ti, Zr, or Hf, and rare earth chalcogenides.

  2. AlSi17Cu5Mg alloy as future material for castings of pistons for internal combustion engines

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2015-07-01

    Full Text Available The paper presents chosen properties and microstructure of AlSi17Cu5Mg alloy as future material for casting pistons in automotive industry. Tests were conducted to elaborate technology of preparation, assessment of crystallisation parameters and shaping the primary structure of the silumin with the aim to improve the working parameters and the functioning efficiency in cylinder-piston system. Refinement of Si crystals, achieved due to overheating above the temperature Tliq. causes that the alloy reaches satisfactory properties in working chamber of the engine are optimised. Such condition of material characteristics causes that hypereutectic silumins, for chosen applications in transport, may serve as an alternative to Al - Si alloys of hypoeutectic and near - eutectic type.

  3. Development of a database system for operational use in the selection of titanium alloys

    Science.gov (United States)

    Han, Yuan-Fei; Zeng, Wei-Dong; Sun, Yu; Zhao, Yong-Qing

    2011-08-01

    The selection of titanium alloys has become a complex decision-making task due to the growing number of creation and utilization for titanium alloys, with each having its own characteristics, advantages, and limitations. In choosing the most appropriate titanium alloys, it is very essential to offer a reasonable and intelligent service for technical engineers. One possible solution of this problem is to develop a database system (DS) to help retrieve rational proposals from different databases and information sources and analyze them to provide useful and explicit information. For this purpose, a design strategy of the fuzzy set theory is proposed, and a distributed database system is developed. Through ranking of the candidate titanium alloys, the most suitable material is determined. It is found that the selection results are in good agreement with the practical situation.

  4. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  5. Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

    Science.gov (United States)

    Yuan, Chen; Jones, Sam; Blackburn, Stuart

    2012-12-01

    Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

  6. Materials selection guidelines for geothermal energy utilization systems

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, P.F. II; Conover, M.F.

    1981-01-01

    This manual includes geothermal fluid chemistry, corrosion test data, and materials operating experience. Systems using geothermal energy in El Salvador, Iceland, Italy, Japan, Mexico, New Zealand, and the United States are described. The manual provides materials selection guidelines for surface equipment of future geothermal energy systems. The key chemical species that are significant in determining corrosiveness of geothermal fluids are identified. The utilization modes of geothermal energy are defined as well as the various physical fluid parameters that affect corrosiveness. Both detailed and summarized results of materials performance tests and applicable operating experiences from forty sites throughout the world are presented. The application of various non-metal materials in geothermal environments are discussed. Included in appendices are: corrosion behavior of specific alloy classes in geothermal fluids, corrosion in seawater desalination plants, worldwide geothermal power production, DOE-sponsored utilization projects, plant availability, relative costs of alloys, and composition of alloys. (MHR)

  7. Nuclear Systems Materials Handbook

    International Nuclear Information System (INIS)

    The NSM Handbook is a multi-volume document being compiled on a continuing basis to meet the broad materials data requirements of those involved in the development of advanced nuclear energy systems. The present focus of the Handbook is upon nuclear systems that have not yet achieved commercial status, with near-term emphasis on the nation's Liquid Metal Fast Breeder Reactor Program. Actual use of the Handbook extends to other advanced nuclear concepts sharing the same needs, and to many nonnuclear engineering activities as well

  8. Quantitative estimation of structure homogeneity of mechanically alloyed dispersion-strengthened composite materials

    International Nuclear Information System (INIS)

    A method of quantitative estimation of microstructure homogeneity of mechanical alloyed composite materials is proposed. As an indicator of satisfactory degree of microstructure homogeneity a value of variation coefficient of 10% is accepted.

  9. NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-based materials for high speed aircraft

    Science.gov (United States)

    Starke, E. A., Jr.

    1993-01-01

    This report on the NASA-UVa Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from January 1, 1992 to June 30, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) powder metallurgy 2XXX alloys, (3) rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  10. On the Choice of Tool Material in Friction Stir Welding of Titanium Alloys

    OpenAIRE

    Settineri, Luca

    2012-01-01

    Friction Stir Welding (FSW) is a solid state welding process patented in 1991 by TWI; initially adopted to weld aluminum alloys, is now being successfully used also for magnesium alloys, copper and steels. The wide diffusion the process is having is due to the possibility to weld both materials traditionally considered difficult to be welded or "unweldable" by traditional fusion welding processes due to peculiar thermal and chemical material properties, and complex geometries as sandwich stru...

  11. Sol-gel derived nanocomposite materials for corrosion protection of aluminium alloys

    OpenAIRE

    Schmidt, Helmut K.; Müller, Peter; Dittfurth, Carola; Albayrak, Sener; Puhl, Anne

    2000-01-01

    Thermally curable nanocomposite coating materials have been developed to seal and protect copper-containing aluminium alloys against corrosion. The coating material was prepared via the sol-gel-process starting from epoxy functionalised silanes, nanoscaled silica and organic diole crosslinker. This coating matrix was additionally supplied with a varying content of cerium oxide (1-20 wt.%). The corrosion protective efficiency of these coatings was investigated on aluminium alloys Al 6013-T6 an...

  12. Crystallization behavior and magnetic properties in High Fe content FeBCSiCu alloy system

    International Nuclear Information System (INIS)

    High Fe content FeBCSiCu nanocrystalline alloys are prepared by annealing melt-spun amorphous ribbons with aim at increasing saturation magnetic flux density. Microstructures identified by XRD and TEM reveal that Cu addition inhibits the surface crystallization of Fe86B7C7 alloy and improve its glass-forming ability. Activation energy of crystallization calculated by Kissinger's equation indicates that both Cu and Si addition promotes the precipitation of α-Fe phase and improves the thermal stability. VSM and DC B–H loop tracer measurements show that the Fe85.5B7C6Si1Cu0.5 nanocrystalline alloy exhibits high saturation magnetic flux density of 1.8 T and low coercivity of 10 A/m, respectively. AC properties measured by AC B–H analyzer show this alloy exhibits low core loss of 0.35 W/kg at 1 T at 50 Hz. Low material cost and convenient productivity make the Fe85.5B7C6Si1Cu0.5 nanocrystalline alloy an economical application in industry. - Highlights: • Cu addition inhibits the surface crystallization and improves the GFA. • The competitive formation of Fe3C and α-Fe phase impedes the devitrification. • Fe85.5B7C6Si1Cu0.5 nanocrystalline alloy exhibits excellent magnetic properties. • The alloy system has an economical advantage and convenient productivity

  13. Novel metallic alloys as phase change materials for heat storage in direct steam generation applications

    Science.gov (United States)

    Nieto-Maestre, J.; Iparraguirre-Torres, I.; Velasco, Z. Amondarain; Kaltzakorta, I.; Zubieta, M. Merchan

    2016-05-01

    Concentrating Solar Power (CSP) is one of the key electricity production renewable energy technologies with a clear distinguishing advantage: the possibility to store the heat generated during the sunny periods, turning it into a dispatchable technology. Current CSP Plants use an intermediate Heat Transfer Fluid (HTF), thermal oil or inorganic salt, to transfer heat from the Solar Field (SF) either to the heat exchanger (HX) unit to produce high pressure steam that can be leaded to a turbine for electricity production, or to the Thermal Energy Storage (TES) system. In recent years, a novel CSP technology is attracting great interest: Direct Steam Generation (DSG). The direct use of water/steam as HTF would lead to lower investment costs for CSP Plants by the suppression of the HX unit. Moreover, water is more environmentally friendly than thermal oils or salts, not flammable and compatible with container materials (pipes, tanks). However, this technology also has some important challenges, being one of the major the need for optimized TES systems. In DSG, from the exergy point of view, optimized TES systems based on two sensible heat TES systems (for preheating of water and superheating vapour) and a latent heat TES system for the evaporation of water (around the 70% of energy) is the preferred solution. This concept has been extensively tested [1, 2, 3] using mainly NaNO3 as latent heat storage medium. Its interesting melting temperature (Tm) of 306°C, considering a driving temperature difference of 10°C, means TES charging steam conditions of 107 bar at 316°C and discharging conditions of 81bar at 296°C. The average value for the heat of fusion (ΔHf) of NaNO3 from literature data is 178 J/g [4]. The main disadvantage of inorganic salts is their very low thermal conductivity (0.5 W/m.K) requiring sophisticated heat exchanging designs. The use of high thermal conductivity eutectic metal alloys has been recently proposed [5, 6, 7] as a feasible alternative. Tms

  14. Corrosion of copper alloys in sulphide containing district heting systems

    DEFF Research Database (Denmark)

    Thorarinsdottir, R.I.; Maahn, Ernst Emanuel

    1999-01-01

    Copper and some copper alloys are prone to corrosion in sulphide containing geothermal water analogous to corrosion observed in district heating systems containing sulphide due to sulphate reducing bacteria. In order to study the corrosion of copper alloys under practical conditions a test...... was carried out at four sites in the Reykjavik District Heating System. The geothermal water chemistry is different at each site. The corrosion rate and the amount and chemical composition of deposits on weight loss coupons of six different copper alloys are described after exposure of 12 and 18 months...

  15. Lithium alloys and metal oxides as high-capacity anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Highlights: •Progress in lithium alloys and metal oxides as anode materials for lithium-ion batteries is reviewed. •Electrochemical characteristics and lithium storage mechanisms of lithium alloys and metal oxides are summarized. •Strategies for improving electrochemical lithium storage properties of lithium alloys and metal oxides are discussed. •Challenges in developing lithium alloys and metal oxides as commercial anodes for lithium-ion batteries are pointed out. -- Abstract: Lithium alloys and metal oxides have been widely recognized as the next-generation anode materials for lithium-ion batteries with high energy density and high power density. A variety of lithium alloys and metal oxides have been explored as alternatives to the commercial carbonaceous anodes. The electrochemical characteristics of silicon, tin, tin oxide, iron oxides, cobalt oxides, copper oxides, and so on are systematically summarized. In this review, it is not the scope to retrace the overall studies, but rather to highlight the electrochemical performances, the lithium storage mechanism and the strategies in improving the electrochemical properties of lithium alloys and metal oxides. The challenges and new directions in developing lithium alloys and metal oxides as commercial anodes for the next-generation lithium-ion batteries are also discussed

  16. Use of Intermetallic Alloys as Reactive Materials for Warhead Applications

    Institute of Scientific and Technical Information of China (English)

    Jürgen Evers; Thomas M.Klapötke

    2015-01-01

    With this communication we want to suggest the system ZrW2 ,a high-density and very hard intermetallic compound that reacts/burns highly exothermic with air at high temperature.This intermetallic phase should provide a very suitable reactive material for warhead applications.

  17. Double Retort System for Materials Compatibility Testing

    International Nuclear Information System (INIS)

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contamination has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented

  18. Double Retort System for Materials Compatibility Testing

    Energy Technology Data Exchange (ETDEWEB)

    V. Munne; EV Carelli

    2006-02-23

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contamination has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented.

  19. Mechanical alloying nanotechnology, materials science and powder metallurgy

    CERN Document Server

    El-Eskandarany, M Sherif

    2015-01-01

    This book is a detailed introduction to mechanical alloying, offering guidelines on the necessary equipment and facilities needed to carry out the process and giving a fundamental background to the reactions taking place. El-Eskandarany, a leading authority on mechanical alloying, discusses the mechanism of powder consolidations using different powder compaction processes. A new chapter will also be included on thermal, mechanically-induced and electrical discharge-assisted mechanical milling. Fully updated to cover recent developments in the field, this second edition also introduces new a

  20. A Computational Investigation of Precipitates in Mg-RE Alloys With Applications To Mg-X Systems

    Science.gov (United States)

    Issa, Ahmed

    Increasing fuel efficiency in transportation vehicles is a major policy goal for both government and auto and aerospace manufacturers. Lightweight structural materials, such as magnesium alloys, hold great promise in enabling such fuel efficiency gains. Understanding the controlling factors in Mg alloy strengthening is crucial for the rational design of structurally strong and inexpensive Mg alloys. In this work, we seek to understand the energetic underpinnings giving rise to a class of remarkably strong Mg alloys: Mg-RE systems. We use first-principles methods to efficiently explore seventeen Mg-RE systems, drawing out broad patterns and distilling our knowledge into simple design rules for Mg alloys. We begin by investigating the controlling factors for the Mg-strengthening prismatic plate precipitates in Mg-RE systems, discovering the critical role of strain in such systems. We then proceed to investigate the surprising role of interfacial energies in determining the course of the Mg-RE precipitation reactions. Using strain and interfacial energies, we construct a phase-field model which accurately depicts the precipitate morphology as a function of time and size in a Mg-Nd system. Finally, we combine our gained insights to implement a computational alloy design scheme on a large portion of the periodic table where we seek Mg-strengthening solutes. Our work advances the understanding of strengthening in Mg alloys and lays the groundwork for full scale computational alloy design.

  1. Dissolution of Plutonium Scrub Alloy and Anode Heel Materials in H-Canyon

    International Nuclear Information System (INIS)

    H-Canyon has a ''gap'' in dissolver operations during the last three months of FY03. One group of material to be processed during the gap is pre-existing scrub alloy material. There are 14 cans of material containing approximately 3.8 kilograms of plutonium. Of the 14 cans, it was anticipated that four cans contain salts, two cans contain anode heel materials, and eight cans contain scrub alloy buttons. H-Canyon desires to process the materials using a flowsheet similar to the SS and C (sand, slag and crucible) dissolution flowsheet used in F-Canyon. The materials will be loaded into carbon steel cans and then placed into aluminum metal charging bundles. Samples were sent to Savannah River Technology Center (SRTC) for characterization and flowsheet testing -- four MSE salts, two anode heels, and seven scrub alloy buttons. SRTC dissolved and characterized each of the samples. Two of them, originally thought to be MSE salts, were found to be graphite mold materials and were unsuitable for processing in H-Canyon. Characterization studies confirmed that the identification of the remaining items as MSE salts, scrub alloy buttons, and anode heel materials was correct. The MSE salts and anode heels solids are comprised primarily of plutonium, potassium, sodium and chloride. Both the MSE salts and anode heels left behind small amounts of residual solids. The scrub alloy buttons are comprised primarily of plutonium and aluminum. The solids dissolve readily with light, effervescent gas generation at the material surface and only trace amounts of NOx generation. Of the seven button samples, four dissolved completely. Two button samples contained small amounts of tantalum that did not dissolve. The last of the seven scrub alloy samples left a trace amount of residual plutonium solids. It is anticipated that the presence of undissolved fissile material is a function of where the sample was located relative to the button surface

  2. Material effects in fretting wear: application to iron, titanium, and aluminum alloys

    Science.gov (United States)

    Blanchard, P.; Colombie, C.; Pellerin, V.; Fayeulle, S.; Vincent, L.

    1991-07-01

    Fretting wear tests were performed on several alloys (low alloyed and stainless steels, Ti6A14V titanium alloy, 2024 and 7075 aluminum alloys) slid against themselves in air under relatively low stresses for various displacements (±15 to ±50 μm). Friction logs, where tangential force is plotted as a function of displacement and number of cycles, were used to characterize the fretting behavior of the materials. Wear scars and cross sections were characterized by optical and scanning electron microscopy. Depending on the amplitude of displacement, sticking, partial slip, or gross slip occurs at the interface. Gross slip leads to debris formation. Metallic particles are detached from localized, very highly deformed areas whose properties and structures are different from those of the initial material. Sticking is observed on titanium and aluminum alloys tested under the smallest displacement. Samples are only deformed elastically. During partial slip, cracks can initiate and propagate in titanium and aluminum alloys. Millimeters-long cracks are observed on aluminum alloys after 106 cycles. Mechanisms for crack formation and propagation are described in terms of fatigue properties.

  3. Effects of molybdenum on microstructural evolution and mechanical properties in Zr–Nb alloys as nuclear fuel cladding materials

    International Nuclear Information System (INIS)

    The Zr–Nb alloys were modified by doping of Mo as a minor alloying element to seek for the nuclear fuel cladding materials with better characteristics. The effects of Mo on microstructural evolution and mechanical properties in Zr–Nb alloys were systematically investigated and elucidated. Results showed that the martensitic microstructure, a mixture of lath martensites and lens martensites with internal twins, was observed in the alloys quenched from β-phase. Width of the lath martensite reduced with the increasing Mo concentration, and the volume fraction of lens martensite increased with increase in the Mo concentration. After final annealing, a new kind of precipitate, namely β-(Nb, Mo, Zr), was identified in the Mo-containing alloys. It was also found that Mo reduced the growth of the precipitates but increased their number density. Furthermore, Mo addition retarded the recrystallization process strongly and reduced the grain size significantly. In terms of the mechanical properties, Mo addition enhanced the yield strength and the ultimate tensile strength at room temperature, however decreased the ductility. The grain size strengthening was presumed as the greatest contributor in this system. (author)

  4. Transmutation of alloys in MFE facilities as calculated by REAC (a computer code system for activation and transmutation)

    International Nuclear Information System (INIS)

    A computer code system for fast calculation of activation and transmutation has been developed. The system consists of a driver code, cross-section libraries, flux libraries, a material library, and a decay library. The code is used to predict transmutations in a Ti-modified 316 stainless steel, a commercial ferritic alloy (HT9), and a V-15%Cr-5%Ti alloy in various magnetic fusion energy (MFE) test facilities and conceptual reactors

  5. Interrelation of material microstructure, ultrasonic factors, and fracture toughness of two phase titanium alloy

    Science.gov (United States)

    Vary, A.; Hull, D. R.

    1982-01-01

    The pivotal role of an alpha-beta phase microstructure in governing fracture toughness in a titanium alloy, Ti-662, is demonstrated. The interrelation of microstructure and fracture toughness is demonstrated using ultrasonic measurement techniques originally developed for nondestructive evaluation and material property characterization. It is shown that the findings determined from ultrasonic measurements agree with conclusions based on metallurgical, metallographic, and fractographic observations concerning the importance of alpha-beta morphology in controlling fracture toughness in two phase titanium alloys.

  6. Selection of alternative material for common rail direct injection system

    Directory of Open Access Journals (Sweden)

    N. Senguttuvan

    2014-03-01

    Full Text Available Common rail direct fuel injection is a modern variant of direct fuel injection system for petrol and diesel engines. The common rail system prototype was developed in the late 1960s by Robert Huber of Switzerland and the technology further developed by Dr. Marco. In petrol engine MPFI technology was developed and implemented in earlier days. Basically common rail tube was fabricated by steel for petrol engines. In the current study Steel, Brass, Aluminum alloy a356 and ABS materials were analyzed separately and aluminum is found the best material among the steel, brass and ABS material for common rail injection tube. Keywords: Common Rail Injection System, Alternate Material.

  7. System for ultra high vacuum made of aluminum alloys

    International Nuclear Information System (INIS)

    We have developed the system for ultra high vacuum made of aluminum alloys for proton and electron synchrotron. This is the first system for ultra high vacuum in which bakable metal seal flange and small diametral bellows of aluminum alloys have been put to practical use. The system consists of the flange protected by a CrN thin film and made of 2219-T87 alloy, the chamber made of 6063-T6 alloy, the aluminum metal gasket of Helico Flex and the bellows made of 5052 alloy. As a result of experiments at the National Laboratory for High Energy Physics (KEK), it had been confirmed that this system shows the special qualities of ultra high vacuum operation, resistance to hard radiation and baking and cooling operations. Up to now, this system has been widely used for the beam lines of the booster synchrotron utilization facility, K1, K2, linac, PI 1 and EP2-B extension of the KEK proton synchrotron. We investigate that this system is applicable to nuclear energy utilization facility and general vacuum apparatus. (author)

  8. Random alloy diffusion kinetics for the application to multicomponent alloy systems

    Science.gov (United States)

    Paul, T. R.; Belova, I. V.; Murch, G. E.

    2016-04-01

    In this paper, extensive Monte Carlo simulation results are reported on tracer and collective diffusion correlation effects in the random ternary alloy, as an example of a multicomponent alloy system. The problem of analytically describing both collective and tracer diffusion kinetics is also addressed for the random multicomponent alloy by application of a combination of the Manning theory and Holdsworth and Elliott theory. It is found that the overall results from the combined theory agree reasonably well with Monte Carlo results. This combined approach is much more accurate than Manning's approach itself and much more manageable than the almost exact, but unfortunately difficult to use, self-consistent theory of Moleko, Allnatt and Allnatt. Some relations between the Onsager phenomenological coefficients and tracer diffusion coefficients are derived and are tested with our Monte Carlo data. Good agreement is found.

  9. Effects of Cerium on Alloy Elements Distribution in Ferrous Matrix Material

    Institute of Scientific and Technical Information of China (English)

    刘英才; 刘俊友; 尹衍生; 刘国权

    2001-01-01

    The effect of the addition of rare earths in Fe-based high chromium alloy powders on elements distribution in matrix materials and mechanical properties were studied. The results show that the addition of cerium can increase the chromium amount in carbonides and increase the micro-hardness after carbonization and the wear-resistant property of materials.

  10. Thermodynamic Analysis on Interaction between MoltenTi Alloys and Oxide Molding Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A thermodynamic model has been built up for the interactions between molten Ti alloys and oxide molding materials in the way of decomposition and solution of molding materials, then the influences on the reaction free energy changes have been calculated and discussed.

  11. Microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system.

    Science.gov (United States)

    Yang, S S; Lin, J Y; Lin, Y T

    1998-09-01

    To investigate the microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system, aluminum alloys A356, AA 5052, AA 5083 and AA 6061 were chosen as the test alloys and Cladosporium and several fuel-oil contaminated microbes isolated in Taiwan were used as test organisms. Aluminum alloy AA 5083 in fuel-oil/aqueous system was the most susceptible material for microbial corrosion, then followed by aluminum alloys AA 5052 and A356, and AA 6061 was more resistant to microbial aggression. Mixed culture had high capability of corrosion, then followed by Penicillium sp. AM-F5, Fusarium sp. AM-F1, Pseudomonas aeruginosa AM-B5, Ps. fluorescens AM-B9, C. resinae ATCC 22712, Penicillium sp. AM-F2, Candida sp. AM-Y1 and Ps. aeruginosa AM-B11. From energy dispersive spectrometer analysis, aluminum and magnesium contents decreased in the corrosion area, while chlorine and sulfur contents increased. The major organic acid produced in fuel-oil/aqueous system was acetic acid, and the total organic acids content had a positive correlation with the degree of microbial corrosion. PMID:10496152

  12. Surface properties of aluminum alloy as material for ultrahigh vacuum

    International Nuclear Information System (INIS)

    The characteristics of aluminum alloy (2017 alloy) for the vacuum chambers of TRISTAN were studied. Machining, electric discharge machining and chemical polishing were made successively on the samples of the 2017 alloy. The observation of surface state, the analysis of surface composition and high temperature desorption experiment were performed. The measurement of surface roughness with a probe, the observation with a scanning electron microscope (SEM), and the measurement of surface roughness factor (SRF) were carried out as the study of the surface state. The analysis of surface composition was made by the Auger electron spectrometry. It was found that the surfaces of samples treated by discharge machining were rough and have thick oxide layer. When chemical polishing was applied to these samples, the surfaces became smooth, and the oxide layer became thin. By heating the samples to raise the temperature, the desorption of H2O, CO and CO2 was caused. The amount of desorption was in close relation with the SRF. (Kato, T.)

  13. Recent progress in R and D on tungsten alloys for divertor structural and plasma facing materials

    Energy Technology Data Exchange (ETDEWEB)

    Wurster, S., E-mail: stefan.wurster@oeaw.ac.at [Erich Schmid Institute of Materials Science, Austria and Association EURATOM-ÖAW, Jahnstrasse 12, A-8700 Leoben (Austria); Baluc, N.; Battabyal, M. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Villigen PSI (Switzerland); Crosby, T. [University of California, Mechanical and Aerospace Engineering Department, Los Angeles, CA (United States); Du, J. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); García-Rosales, C. [Centro de Estudios e Investigaciones Técnicas de Gipuzkoa (CEIT), San Sebastián (Spain); Hasegawa, A. [Department of Quantum Science and Energy Engineering, Faculty of Engineering, Tohoku University (Japan); Hoffmann, A. [Plansee Metall GmbH, Reutte (Austria); Kimura, A. [Institute of Advanced Energy, Kyoto University (Japan); Kurishita, H. [International Research Center for Nuclear Material Science, Institute for Materials Research, Tohoku University (Japan); Kurtz, R.J. [Pacific Northwest National Laboratory, Richland, WA (United States); Li, H. [Erich Schmid Institute of Materials Science, Austria and Association EURATOM-ÖAW, Jahnstrasse 12, A-8700 Leoben (Austria); Chair of Atomistic Modelling and Design of Materials, University of Leoben, Leoben (Austria); Noh, S.; Reiser, J. [Karlsruhe Institute of Technology, Karlsruhe (Germany); Riesch, J. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Rieth, M. [Karlsruhe Institute of Technology, Karlsruhe (Germany); Setyawan, W. [Pacific Northwest National Laboratory, Richland, WA (United States); Walter, M. [Karlsruhe Institute of Technology, Karlsruhe (Germany); You, J.-H. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); and others

    2013-11-15

    Tungsten materials are candidates for plasma-facing components for the International Thermonuclear Experimental Reactor and the DEMOnstration power plant because of their superior thermophysical properties. Because these materials are not common structural materials like steels, knowledge and strategies to improve the properties are still under development. These strategies discussed here, include new alloying approaches and microstructural stabilization by oxide dispersion strengthened as well as TiC stabilized tungsten based materials. The fracture behavior is improved by using tungsten laminated and tungsten wire reinforced materials. Material development is accompanied by neutron irradiation campaigns. Self-passivation, which is essential in case of loss-of-coolant accidents for plasma facing materials, can be achieved by certain amounts of chromium and titanium. Furthermore, modeling and computer simulation on the influence of alloying elements and heat loading and helium bombardment will be presented.

  14. Material characterization and finite element simulations of aluminum alloy sheets during non-isothermal forming process

    Science.gov (United States)

    Zhang, Nan

    The utilization of more non-ferrous materials is one of the key factors to succeed out of the constantly increasing demand for lightweight vehicles in automotive sector. Aluminum-magnesium alloys have been identified as the most promising substitutions to the conventional steel without significant compromise in structural stiffness and strength. However, the conventional forming methods to deform the aluminum alloy sheets are either costly or insufficient in formability which limit the wide applications of aluminum alloy sheets. A recently proposed non-isothermal hot stamping approach, which is also referred as Hot Blank - Cold Die (HB-CD) stamping, aims at fitting the commercial grade aluminum alloy sheets, such as AA5XXX and AA7XXX, into high-volume and cost-effective production for automotive sector. In essence, HB-CD is a mutation of the conventional hot stamping approach for boron steel (22MnB5) which deforms the hot blank within the cold tool set. By elevating the operation temperature, the formability of aluminum alloy sheets can be significantly improved. Meanwhile, heating the blank only and deforming within the cold tool sets allow to reduce the energy and time consumed. This research work aims at conducting a comprehensive investigation of HB-CD with particular focuses on material characterization, constitutive modeling and coupled thermo-mechanical finite element simulations with validation. The material properties of AA5182-O, a popular commercial grade of aluminum alloy sheet in automotive sector, are obtained through isothermal tensile testing at temperatures from 25° to 300°, covering a quasi-static strain-rate range (0.001--0.1s-1). As the state-of-the-art non-contact strain measurement technique, digital image correlation (DIC) system is utilized to evaluate the stress-strain curves as well as to reveal the details of material deformation with full-field and multi-axis strain measurement. Material anisotropy is characterized by extracting the

  15. Microstructure and mechanical properties of Ti-15Zr alloy used as dental implant material.

    Science.gov (United States)

    Medvedev, Alexander E; Molotnikov, Andrey; Lapovok, Rimma; Zeller, Rolf; Berner, Simon; Habersetzer, Philippe; Dalla Torre, Florian

    2016-09-01

    Ti-Zr alloys have recently started to receive a considerable amount of attention as promising materials for dental applications. This work compares mechanical properties of a new Ti-15Zr alloy to those of commercially pure titanium Grade4 in two surface conditions - machined and modified by sand-blasting and etching (SLA). As a result of significantly smaller grain size in the initial condition (1-2µm), the strength of Ti-15Zr alloy was found to be 10-15% higher than that of Grade4 titanium without reduction in the tensile elongation or compromising the fracture toughness. The fatigue endurance limit of the alloy was increased by around 30% (560MPa vs. 435MPa and 500MPa vs. 380MPa for machined and SLA-treated surfaces, respectively). Additional implant fatigue tests showed enhanced fatigue performance of Ti-15Zr over Ti-Grade4. PMID:27258932

  16. Titanium–35niobium alloy as a potential material for biomedical implants: In vitro study

    International Nuclear Information System (INIS)

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium–niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti–35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150 μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti–35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti–35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti–35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. - Highlights: • Powder metallurgy is effective in producing porous biomaterials. • Ti–35Nb alloy improved mineralized matrix formation. • Porous surface favored a multidirectional pattern of cell spreading. • Porous surface Ti–35Nb alloy appears to be more favorable to bone formation than existing alloys

  17. Titanium–35niobium alloy as a potential material for biomedical implants: In vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Andrade, Dennia; Marotta Reis de Vasconcellos, Luana; Chaves Silva Carvalho, Isabel; Ferraz de Brito Penna Forte, Lilibeth; Souza Santos, Evelyn Luzia de [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil); Falchete do Prado, Renata, E-mail: renatafalchete@hotmail.com [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil); Santos, Dalcy Roberto dos; Alves Cairo, Carlos Alberto [Division of Materials, Air and Space Institute, CTA, Praça Mal. do Ar Eduardo Gomes, 14, São José dos Campos 12904-000, SP (Brazil); Rodarte Carvalho, Yasmin [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, UNESP — Univ Estadual Paulista, State University of São Paulo (UNESP), Av. Engenheiro Francisco José Longo, 777, São José dos Campos 12245-000, SP (Brazil)

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium–niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti–35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150 μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti–35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti–35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti–35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. - Highlights: • Powder metallurgy is effective in producing porous biomaterials. • Ti–35Nb alloy improved mineralized matrix formation. • Porous surface favored a multidirectional pattern of cell spreading. • Porous surface Ti–35Nb alloy appears to be more favorable to bone formation than existing alloys.

  18. Lunar Materials Handling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of bulk materials and products into and out of process equipment in support of lunar and Mars in...

  19. Materials Properties of Modifeied Ni-Based Alloy

    Directory of Open Access Journals (Sweden)

    Kraus, L.

    2007-01-01

    Full Text Available The thermomechanical processing of NiMoCr solid solution nickel base superalloy is the way to considerably influence the grain size. As uniform coarse grain size increases the creep strength and crack growth resistance. In the work, the processing to achieve uniform recrystallized grain structure with variation of thermomechanical parameters is investigated. The creep behavior of the alloy after various hot working conditions is determined. The results of creep tests showed that creep characteristics such as strain rate and lifetime were greatly dependent on the initial hot working conditions and annealing parameters.

  20. The Effect of Novel Mercapto Silane Systems on Resin Bond Strength to Dental Noble Metal Alloys.

    Science.gov (United States)

    Lee, Yangho; Kim, Kyo-Han; Kim, Young Kyung; Son, Jun Sik; Lee, Eunkyung; Kwon, Tae-Yub

    2015-07-01

    Self-assembled monolayers of thiols (RSH), which are key elements in nanoscience and nanotechnology, have been used to link a range of materials to planar gold surfaces or gold nanoparticles. In this study, the adhesive performance of mercapto silane systems to dental noble metal alloys was evaluated in vitro and compared with that of commercial dental primers. Dental gold-palladium-platinum (Au-Pd-Pt), gold-palladium-silver (Au-Pd-Ag), and palladium-silver (Pd-Ag) alloys were used as the bonding substrates after air-abrasion (sandblasting). One of the following primers was applied to each alloy: (1) no primer treatment (control), (2) three commer- cial primers: V-Primer, Metal Primer II, and M.L. Primer, and (3) two experimental silane primer systems: 2-step application with 3-mercaptopropyltrimethoxysilane (SPS) (1.0 wt%) and then 3-methacryloxypropyltrimethoxysilane (MPS) (1.0 wt%), and a silane blend consisting of SPS and MPS (both 1.0 wt%). Composite resin cylinders with a diameter of 2.38 mm were bonded to the surfaces and irradiated for 40 sec using a curing light. After storage in water at 37 °C for 24 h, all the bonded specimens were thermocycled 5000 times before the shear bond strength test. Regardless of the alloy type, the mercapto silane systems (both the 2-step and blend systems) consistently showed superior bonding performance than the commercial primers. Contact angle analysis of the primed surfaces indicated that higher resin bond strengths were produced on more hydrophilic alloy surfaces. These novel mercapto silane systems are a promising alternative for improving resin bonding to dental noble metal alloys. PMID:26373046

  1. Effect of substitutional element in the microstructure and hardness of Ti-Zr system alloys used as biomaterials

    International Nuclear Information System (INIS)

    New titanium alloys had been developed with the aim of obtaining materials with improved properties for application as biomaterial, and alloys of the Ti-Zr system are among those most promising. The objective of this study is to analyze the influence of the zirconium concentration on microstructure and hardness of the Ti-5Zr, Ti-10Zr and Ti-15Zr alloys. After arc-melting melting, the samples were analyzed by chemical and gas composition, and characterized by density measurements, optical microscopy, x-ray diffraction and hardness. The results showed a microstructure formed by alpha phase (hexagonal close-packed structure) and increased of hardness. (author)

  2. Low Temperature Shape Memory Alloys for Adaptive, Autonomous Systems Project

    Science.gov (United States)

    Falker, John; Zeitlin, Nancy; Williams, Martha; Benafan, Othmane; Fesmire, James

    2015-01-01

    The objective of this joint activity between Kennedy Space Center (KSC) and Glenn Research Center (GRC) is to develop and evaluate the applicability of 2-way SMAs in proof-of-concept, low-temperature adaptive autonomous systems. As part of this low technology readiness (TRL) activity, we will develop and train low-temperature novel, 2-way shape memory alloys (SMAs) with actuation temperatures ranging from 0 C to 150 C. These experimental alloys will also be preliminary tested to evaluate their performance parameters and transformation (actuation) temperatures in low- temperature or cryogenic adaptive proof-of-concept systems. The challenge will be in the development, design, and training of the alloys for 2-way actuation at those temperatures.

  3. Standard Test Method for Stress-Corrosion of Titanium Alloys by Aircraft Engine Cleaning Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method establishes a test procedure for determining the propensity of aircraft turbine engine cleaning and maintenance materials for causing stress corrosion cracking of titanium alloy parts. 1.2 The evaluation is conducted on representative titanium alloys by determining the effect of contact with cleaning and maintenance materials on tendency of prestressed titanium alloys to crack when subsequently heated to elevated temperatures. 1.3 Test conditions are based upon manufacturer's maximum recommended operating solution concentration. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see and .

  4. Titanium-35niobium alloy as a potential material for biomedical implants: In vitro study.

    Science.gov (United States)

    de Andrade, Dennia Perez; de Vasconcellos, Luana Marotta Reis; Carvalho, Isabel Chaves Silva; Forte, Lilibeth Ferraz de Brito Penna; de Souza Santos, Evelyn Luzia; Prado, Renata Falchete do; Santos, Dalcy Roberto Dos; Cairo, Carlos Alberto Alves; Carvalho, Yasmin Rodarte

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium-niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti-35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti-35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti-35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti-35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants.

  5. Titanium-35niobium alloy as a potential material for biomedical implants: In vitro study.

    Science.gov (United States)

    de Andrade, Dennia Perez; de Vasconcellos, Luana Marotta Reis; Carvalho, Isabel Chaves Silva; Forte, Lilibeth Ferraz de Brito Penna; de Souza Santos, Evelyn Luzia; Prado, Renata Falchete do; Santos, Dalcy Roberto Dos; Cairo, Carlos Alberto Alves; Carvalho, Yasmin Rodarte

    2015-11-01

    Research on new titanium alloys and different surface topographies aims to improve osseointegration. The objective of this study is to analyze the behavior of osteogenic cells cultivated on porous and dense samples of titanium-niobium alloys, and to compare them with the behavior of such type of cells on commercial pure titanium. Samples prepared using powder metallurgy were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and metallographic and profilometer analyses. Osteogenic cells from newborn rat calvaria were plated over different groups: dense or porous samples composed of Ti or Ti-35niobium (Nb). Cell adhesion, cell proliferation, MTT assay, cell morphology, protein total content, alkaline phosphatase activity, and mineralization nodules were assessed. Results from XRD and EDS analysis confirmed the presence of Ti and Nb in the test alloy. Metallographic analysis revealed interconnected pores, with pore size ranging from 138 to 150μm. The profilometer analysis detected the greatest rugosity within the dense alloy samples. In vitro tests revealed similar biocompatibility between Ti-35Nb and Ti; furthermore, it was possible to verify that the association of porous surface topography and the Ti-35Nb alloy positively influenced mineralized matrix formation. We propose that the Ti-35Nb alloy with porous topography constitutes a biocompatible material with great potential for use in biomedical implants. PMID:26249625

  6. Endothelial responses of magnesium and other alloying elements in magnesium-based stent materials

    Science.gov (United States)

    Zhao, Nan; Zhu, Donghui

    2016-01-01

    Biodegradable tailored magnesium (Mg) alloys are some of the most promising scaffolds for cardiovascular stents. During the course of degradation after implantation, all the alloying elements in the scaffold will be released to the surrounding vascular tissues. However, fundamental questions regarding the toxicity of alloying elements towards vascular cells, the maximum amount of each element that could be used in alloy design, or how each of the alloying elements affects vascular cellular activity and gene expression, are still not fully answered. This work systematically addressed these questions by revealing how application of different alloying elements commonly used in Mg stent materials influences several indices of human endothelial cell health, i.e., viability, proliferations, cytoskeletal reorganizations, migration, and the gene expression profile. The overall cell viability and proliferation showed a decreasing trend with increasing concentrations of the ions, and the half maximal effective concentrations (EC50) for each element were determined. When applied at a low concentration of around 10 mM, Mg had no adverse effects but improved cell proliferation and migration instead. Mg ions also altered endothelial gene expression significantly in a dose dependent manner. Most of the changed genes are related to angiogenesis and the cell adhesion signaling pathways. Findings from this work provide useful information on maximum safe doses of these ions for endothelial cells, endothelial responses towards these metal ions, and some guidance for future Mg stent design. PMID:25363018

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-30

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-30

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

  9. STRUCTURAL HEALTH MONITORING IN COMPOSITE MATERIALS USING EMBEDDED SHAPE MEMORY ALLOY(SMA) WIRE SENSORS

    Institute of Scientific and Technical Information of China (English)

    QIU Zixue; YAO Xingtian; COSTAS Soutis

    2006-01-01

    Shape memory alloy (SMA) materials possess completely superelasticity or pseudoelasticity above the austenite finish temperature and many unique mechanical, thermal,thermal-mechanical and electrical properties compared with other conventional materials. Many studies have reported that the superelastic and hysteresis properties of the SMA materials can absorb energies coming from external excitations or sudden impacts. In addition, due to the special electrical properties of NiTi superelastic wires, they can also be used as strain-sensing elemem to monitor structural health conditions. Composite laminated specimens embedded with SMA wire sensors are fabricated and detailed testing system is designed such as multi-parameters measuring for impact and weak signal processing for SMA sensor. Low velocity impact test shows that SMA wire sensors embedded in fiber-reinforced plastic (FRP) laminate can be well used to monitor impact responses,such as the location of impact damage, impact degree, and strain distribution. Experimental results and theoretical predictions reveal almost the same. Comparing with other method, a simple, economic and reliable technique method monitoring important engineering structures on line is provided.

  10. Crystallization behavior and magnetic properties in High Fe content FeBCSiCu alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Fan, X.D., E-mail: fanxd@seu.edu.cn; Shen, B.L., E-mail: blshen@seu.edu.cn

    2015-07-01

    High Fe content FeBCSiCu nanocrystalline alloys are prepared by annealing melt-spun amorphous ribbons with aim at increasing saturation magnetic flux density. Microstructures identified by XRD and TEM reveal that Cu addition inhibits the surface crystallization of Fe{sub 86}B{sub 7}C{sub 7} alloy and improve its glass-forming ability. Activation energy of crystallization calculated by Kissinger's equation indicates that both Cu and Si addition promotes the precipitation of α-Fe phase and improves the thermal stability. VSM and DC B–H loop tracer measurements show that the Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy exhibits high saturation magnetic flux density of 1.8 T and low coercivity of 10 A/m, respectively. AC properties measured by AC B–H analyzer show this alloy exhibits low core loss of 0.35 W/kg at 1 T at 50 Hz. Low material cost and convenient productivity make the Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy an economical application in industry. - Highlights: • Cu addition inhibits the surface crystallization and improves the GFA. • The competitive formation of Fe{sub 3}C and α-Fe phase impedes the devitrification. • Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy exhibits excellent magnetic properties. • The alloy system has an economical advantage and convenient productivity.

  11. Development and characterization of Powder Metallurgy (PM) 2XXX series Al alloy products and Metal Matrix Composite (MMC) 2XXX Al/SiC materials for high temperature aircraft structural applications

    Science.gov (United States)

    Chellman, D. J.; Gurganus, T. B.; Walker, J. A.

    1992-01-01

    The results of a series of material studies performed by the Lockheed Aeronautical Systems Company over the time period from 1980 to 1991 are discussed. The technical objective of these evaluations was to develop and characterize advanced aluminum alloy materials with temperature capabilities extending to 350 F. An overview is given of the first five alloy development efforts under this contract. Prior work conducted during the first five modifications of the alloy development program are listed. Recent developments based on the addition of high Zr levels to an optimum Al-Cu-Mg alloy composition by powder metallurgy processing are discussed. Both reinforced and SiC or B4C ceramic reinforced alloys were explored to achieve specific target goals for high temperature aluminum alloy applications.

  12. Structural materials challenges for advanced reactor systems

    Science.gov (United States)

    Yvon, P.; Carré, F.

    2009-03-01

    Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials

  13. Radiation Resistance Studies of Amorphous Silicon Alloy Photovoltaic Materials

    Science.gov (United States)

    Woodyard, James R.

    1994-01-01

    The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys was investigated. A number of different device structures were irradiated with 1.0 MeV protons. The cells were insensitive to proton fluences below 1E12 sq cm. The parameters of the irradiated cells were restored with annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters for fluences below lE14 sq cm require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed in dark I-V measurements. The current mechanisms were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

  14. Molybdenum and molybdenum alloys as materials for high temperature furnaces and hot isostatic presses

    Energy Technology Data Exchange (ETDEWEB)

    Aschenbrenner, W.; Palme, R.

    1983-04-01

    Owing to their excellent high-temperature properties molybdenum and the molybdenum alloy TZM are used as materials for high-temperature furnaces and hot isostatic presses. The setup and the function of the high-temperature furnaces and hot isostatic presses and their applications are described.

  15. Photovoltaic semiconductor materials based on alloys of tin sulfide, and methods of production

    Energy Technology Data Exchange (ETDEWEB)

    Lany, Stephan

    2016-06-07

    Photovoltaic thin-film materials comprising crystalline tin sulfide alloys of the general formula Sn.sub.1-x(R).sub.xS, where R is selected from magnesium, calcium and strontium, as well as methods of producing the same, are disclosed.

  16. Selection of alternative material for common rail direct injection system

    OpenAIRE

    Senguttuvan, N.; Raja, S; R. Sasidharan

    2014-01-01

    Common rail direct fuel injection is a modern variant of direct fuel injection system for petrol and diesel engines. The common rail system prototype was developed in the late 1960s by Robert Huber of Switzerland and the technology further developed by Dr. Marco. In petrol engine MPFI technology was developed and implemented in earlier days. Basically common rail tube was fabricated by steel for petrol engines. In the current study Steel, Brass, Aluminum alloy a356 and ABS materials were anal...

  17. Nuclear data information system for nuclear materials

    International Nuclear Information System (INIS)

    The conceptual system for nuclear material design is considered and some trials on WWW server with functions of the easily accessible simulation of nuclear reactions are introduced. Moreover, as an example of the simulation on the system using nuclear data, transmutation calculation was made for candidate first wall materials such as 9Cr-2W steel, V-5Cr-5Ti and SiC in SUS316/Li2O/H2O(SUS), 9Cr-2W/Li2O/H2O(RAF), V alloy/Li/Be(V), and SiC/Li2ZrO3/He(SiC) blanket/shield systems based on ITER design model. Neutron spectrum varies with different blanket/shield compositions. The flux of low energy neutrons decreases in order of V< SiC< RAF< SUS blanket/shield systems. Fair amounts of W depletion in 9Cr-2W steel and the increase of Cr content in V-5Cr-5Ti were predicted in SUS or RAF systems. Concentration change in W and Cr is estimated to be suppressed if Li coolant is used in place of water. Helium and hydrogen production are not strongly affected by the different blanket/shield compositions. (author)

  18. Ab-initio vibrational properties of transition metal chalcopyrite alloys determined as high-efficiency intermediate-band photovoltaic materials

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, P. [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM. Ciudad Universitaria s/n, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica, CSIC. Marie Curie 2, Cantoblanco, 28049 Madrid (Spain)], E-mail: pablop@etsit.upm.es; Aguilera, I.; Wahnon, P. [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM. Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2008-08-30

    In this work, we present frozen phonon and linear response ab-initio research into the vibrational properties of the CuGaS{sub 2} chalcopyrite and transition metal substituted (CuGaS{sub 2})M alloys. These systems are potential candidates for developing a novel solar-cell material with enhanced optoelectronic properties based in the implementation of the intermediate-band concept. We have previously carried out ab-initio calculations of the electronic properties of these kinds of chalcopyrite metal alloys showing a narrow transition metal band isolated in the semiconductor band gap. The substitutes used in the present work are the 3d metal elements, Titanium and Chromium. For the theoretical calculations we use standard density functional theory at local density and generalized gradient approximation levels. We found that the optical phonon branches of the transition metal chalcopyrite, are very sensitive to the specific bonding geometry and small changes in the transition metal environment.

  19. Solid state amorphisation in binary systems prepared by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, G., E-mail: gemagonz@ivic.v [Lab. Ciencia e Ing. de Materiales, Instituto Venezolano de Investigaciones Cientificas, IVIC, Caracas (Venezuela, Bolivarian Republic of); Sagarzazu, A. [Lab. Ciencia e Ing. de Materiales, Instituto Venezolano de Investigaciones Cientificas, IVIC, Caracas (Venezuela, Bolivarian Republic of); Bonyuet, D. [Instituto de Investigacion en Biomedicina y Ciencias Aplicadas, Universidad de Oriente, Cumana (Venezuela, Bolivarian Republic of); D' Angelo, L. [UNEXPO, Universidad Experimental Politecnica Luis Caballero Mejias, Dpto. Ing. Mecanica (Venezuela, Bolivarian Republic of); Villalba, R. [Lab. Ciencia e Ing. de Materiales, Instituto Venezolano de Investigaciones Cientificas, IVIC, Caracas (Venezuela, Bolivarian Republic of)

    2009-08-26

    In the present work a detailed study of amorphisation in different systems prepared by mechanical alloying under the same experimental conditions was carried out, milling up to 50 and 100 h in some cases. The systems studied were: AlTi, AlNi, AlFe, FeNi, FeCo, NiMo, NiW, NiCo, MoW, CoMo. These systems were chosen to study the effect of Al-transition metal, transition metal-transition metal and also systems with large and small negative heat of mixing, different and similar crystal structures, atomic sizes and diffusion coefficients. Calculations based on the Miedema model for alloy formation and amorphisation on all the alloys studied were performed. The experimental results from X-ray diffraction and transmission electron microscopy showed that the systems based on Fe (FeNi, FeCo and FeAl) did not amorphised, even after milling for 100 h, and formed a stable solid solution with a nanometric grain size of 7 nm. The systems NiMo, NiW, MoW and CoMo (systems with small negative heat of mixing), showed amorphisation after 50 h of milling. NiAl and TiAl form an intermediate amorphous phase after around 20 h of milling and with further milling they recrystallize into a fcc solid solution. Agreement between the theoretical calculations based on the Miedema model and the experimental results was found in most of the systems.

  20. Hydriding and Dehydriding Characteristics of Mechanically Alloyed LaMg17Ni Composite Material

    Institute of Scientific and Technical Information of China (English)

    李谦; 蒋利军; 林勤; 周国治; 詹峰; 郑强; 魏秀英

    2003-01-01

    A composite material with the nominal composition LaMg17Ni was synthesized by mechanical alloying and the hydriding/dehydriding (H/D) behaviors of this material were studied at several temperatures. This material has a hydrogen storage capacity (5.76% H2, mass fraction) lower than conventionally alloyed La2Mg17 (6.63% H2, mass fraction) without activation but shows a superior hydriding/dehydriding kinetic property. At 523 K it absorbed 4.97% (mass fraction) in less than 1 min, approximately 100 times faster than La2Mg17 alloy under the same conditions. This attractive kinetic property of the alloy can be ascribed to the catalytic action of Mg2Ni, LaH2 and La as well as the multiphase structure formed in the preparation processes. The relationships between the equilibrium plateau pressure and the temperature can be expressed as lgpeq=-2797/T+4.267 (553 K≤T≤623 K) for hydriding and lgpeq=-3957/T+6.063(553 K≤T≤623 K) for dehydriding.

  1. Review of PWSCC and mitigation management strategies of Alloy 600 materials of PWRs

    Science.gov (United States)

    Hwang, Seong Sik

    2013-11-01

    Primary water stress corrosion cracking (PWSCC) of Alloy 600 penetration nozzles in pressurized water reactors (PWRs) was reported in the control rod drive mechanism (CRDM), pressurizer instrumentation, and pressurizer heater sleeves. Recently, two cases of boric acid precipitation that indicated leaking of the primary cooling water were reported on the bottom head surface of the steam generators (SGs) in Korea. PWSCC crack indication in CRDM was also detected in a Korea plant. It is necessary to set up a rigid maintenance and inspection guidelines for the components. The PWSCC history of Alloy 600 penetration nozzles of PWRs and maintenance strategies are reviewed based upon the open literature and some experiences in Korea. The inspection requirements, repair techniques such as material changes, the isolation, weld overlays, stress improvements, water chemistry changes are reviewed. Management strategies for the Alloy 600 nozzles are also described.

  2. Review of PWSCC and mitigation management strategies of Alloy 600 materials of PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Sik, E-mail: sshwang@kaeri.re.kr

    2013-11-15

    Primary water stress corrosion cracking (PWSCC) of Alloy 600 penetration nozzles in pressurized water reactors (PWRs) was reported in the control rod drive mechanism (CRDM), pressurizer instrumentation, and pressurizer heater sleeves. Recently, two cases of boric acid precipitation that indicated leaking of the primary cooling water were reported on the bottom head surface of the steam generators (SGs) in Korea. PWSCC crack indication in CRDM was also detected in a Korea plant. It is necessary to set up a rigid maintenance and inspection guidelines for the components. The PWSCC history of Alloy 600 penetration nozzles of PWRs and maintenance strategies are reviewed based upon the open literature and some experiences in Korea. The inspection requirements, repair techniques such as material changes, the isolation, weld overlays, stress improvements, water chemistry changes are reviewed. Management strategies for the Alloy 600 nozzles are also described.

  3. Review of PWSCC and mitigation management strategies of Alloy 600 materials of PWRs

    International Nuclear Information System (INIS)

    Primary water stress corrosion cracking (PWSCC) of Alloy 600 penetration nozzles in pressurized water reactors (PWRs) was reported in the control rod drive mechanism (CRDM), pressurizer instrumentation, and pressurizer heater sleeves. Recently, two cases of boric acid precipitation that indicated leaking of the primary cooling water were reported on the bottom head surface of the steam generators (SGs) in Korea. PWSCC crack indication in CRDM was also detected in a Korea plant. It is necessary to set up a rigid maintenance and inspection guidelines for the components. The PWSCC history of Alloy 600 penetration nozzles of PWRs and maintenance strategies are reviewed based upon the open literature and some experiences in Korea. The inspection requirements, repair techniques such as material changes, the isolation, weld overlays, stress improvements, water chemistry changes are reviewed. Management strategies for the Alloy 600 nozzles are also described

  4. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    International Nuclear Information System (INIS)

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute α grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase (α and β) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase α and near-α (Ti Gr 12) alloys

  5. Degradation mode survey candidate titanium-base alloys for Yucca Mountain project waste package materials. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.

    1997-12-01

    The Yucca Mountain Site Characterization Project (YMP) is evaluating materials from which to fabricate high-level nuclear waste containers (hereafter called waste packages) for the potential repository at Yucca Mountain, Nevada. Because of their very good corrosion resistance in aqueous environments titanium alloys are considered for container materials. Consideration of titanium alloys is understandable since about one-third (in 1978) of all titanium produced is used in applications where corrosion resistance is of primary importance. Consequently, there is a considerable amount of data which demonstrates that titanium alloys, in general, but particularly the commercial purity and dilute {alpha} grades, are highly corrosion resistant. This report will discuss the corrosion characteristics of Ti Gr 2, 7, 12, and 16. The more highly alloyed titanium alloys which were developed by adding a small Pd content to higher strength Ti alloys in order to give them better corrosion resistance will not be considered in this report. These alloys are all two phase ({alpha} and {beta}) alloys. The palladium addition while making these alloys more corrosion resistant does not give them the corrosion resistance of the single phase {alpha} and near-{alpha} (Ti Gr 12) alloys.

  6. Japanese R&D on new cast alloys and materials

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, H.W.

    1996-05-01

    On the basis of observations of the JTEC team, it appears that Japanese universities and research institutes are leading long-term R&D thrusts for development of new materials casting technologies. Significant efforts include amorphous metals, intermetallics, application of MHD in continuous casting of steel, and energy efficient furnace technology. Industrial R&D seems focused more on process improvements than on new product technologies, but significant efforts in new cast materials included cast metal matrix composites, materials substitutions for thinner wall products, and advanced ceramic products for foundry industry applications.

  7. Micro-scale mechanics of the surface-nanocrystalline Al-alloy material

    Institute of Scientific and Technical Information of China (English)

    WEI Yueguang; ZHU Chen; WU Xiaolei

    2004-01-01

    Based on the microscopic observations and measurements, the mechanical behavior of the surface-nanocrystallized Al-alloy material at microscale is investigated experimentally and theoretically. In the experimental research, the compressive stress-strain curves and the hardness depth curves are measured. In the theoretical simulation, based on the material microstructure characteristics and the experimental features of the compression and indentation, the microstructure cell models are developed and the strain gradient plasticity theory is adopted. The material compressive stress-strain curves and the hardness depth curves are predicted and simulated. Through comparison of the experimental results with the simulation results, the material and model parameters are determined.

  8. Chemical equilibrium studies of tritium--lithium and tritium--lithium alloy systems

    International Nuclear Information System (INIS)

    In deuterium-tritium fusion reactors currently under design, the production of tritium is accomplished by utilizing a lithium-bearing blanket. Lithium metal is presently the leading candidate for the blanket material, although molten Li2BeF4, solid Li--Al (50-50 at. percent) alloy and other lithium-containing materials are distinct possibilities. This paper summarizes progress of ongoing studies of the thermodynamics of some of these lithium containing systems. The individual solubilities of hydrogen, deuterium, and tritium in lithium as a function of temperature (700 to 10000C) and pressure are presented. Recent work with the solid alloy Li--Al (50-50 at. percent) has shown that the tritium solubility between 400 and 6000C is low. When the tritium pressure was between 0.14 and 0.52 torr, the Li--Al samples contained only 1 to 4 ppm tritium

  9. Lunar Materials Handling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of lunar soil into and out of process equipment in support of in situ resource utilization...

  10. Information system revives materials management

    International Nuclear Information System (INIS)

    Through a change in philosophy and the development of a new, more efficient information management system, Arizona Public Service Co. (APSW) has, in less than two years, reduced material and service costs by 10 percent. The utility plans to cut these costs form 1993 figures by 25 percent before 2000. The utility is breaking new ground with ongoing implementation of new business processes and the new Materials Logistics Information System (MLIS), which has been co-developed with Texas Instruments Software Division (TISD)

  11. Mold Materials For Permanent Molding of Aluminum Alloys

    Energy Technology Data Exchange (ETDEWEB)

    John F Wallace; David Schwam; Wen Hong dxs11@po.cwru.edu

    2001-09-14

    A test that involves immersion of the potential mod materials for permanent molds has been developed that provides a thermal cycle that is similar to the experienced during casting of aluminum in permanent molds. This test has been employed to determine the relative thermal fatigue resistance of several different types of mold materials. Four commercial mold coatings have been evaluated for their insulating ability, wear resistance and roughness. The results indicate that composition and structure of the mold materials have considerable effect on their thermal fatigue cracking behavior. Irons with a gray iron structure are the most prone to thermal fatigue cracking followed by compacted graphite irons with the least thermal fatigue cracking of the cast irons experienced by ductile iron. The composition of these various irons affects their behavior.

  12. Experimental analyses of dynamical systems involving shape memory alloys

    DEFF Research Database (Denmark)

    Enemark, Søren; Savi, Marcelo A.; Santos, Ilmar F.

    2015-01-01

    The use of shape memory alloys (SMAs) in dynamical systems has an increasing importance in engineering especially due to their capacity to provide vibration reductions. In this regard, experimental tests are essential in order to show all potentialities of this kind of systems. In this work, SMA...... springs are incorporated in a dynamical system that consists of a one degree of freedom oscillator connected to a linear spring and a mass, which is also connected to the SMA spring. Two types of springs are investigated defming two distinct systems: a pseudoelastic and a shape memory system...

  13. Materials challenges for nuclear systems

    Directory of Open Access Journals (Sweden)

    Todd Allen

    2010-12-01

    Full Text Available The safe and economical operation of any nuclear power system relies to a great extent, on the success of the fuel and the materials of construction. During the lifetime of a nuclear power system which currently can be as long as 60 years, the materials are subject to high temperature, a corrosive environment, and damage from high-energy particles released during fission. The fuel which provides the power for the reactor has a much shorter life but is subject to the same types of harsh environments. This article reviews the environments in which fuels and materials from current and proposed nuclear systems operate and then describes how the creation of the Advanced Test Reactor National Scientific User Facility is allowing researchers from across the United States to test their ideas for improved fuels and materials.

  14. ANALYSIS OF THE SURFACE PROFILE AND ITS MATERIAL SHARE DURING THE GRINDING INCONEL 718 ALLOY

    Directory of Open Access Journals (Sweden)

    Martin Novák

    2015-05-01

    Full Text Available Grinding is still an important method for surface finishing. At FPTM JEPU research, which deals with this issue is conducted. Experiments are carried out with grinding various materials under different conditions and then selected components of the surface integrity are evaluated. They include roughness Ra, Rm and Rz, Material ratio curve (Abbott Firestone curve and also the obtained roundness. This article deals with grinding nickel Inconel 718 alloy, when selected cutting grinding conditions were used and subsequently the surface profile and the material ratio curve were measured and evaluated.

  15. Erosion resistance in a stationary arc of powder materials on the base of heat resisting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Minakova, R.V.; Kostenetskaya, L.I.; Krusanova, A.P.; Kukhtikov, V.A.; Smirnov, A.V.; Lugovskaya, E.S. (AN Ukrainskoj SSR, Kiev. Inst. Problem Materialovedeniya)

    1983-08-01

    Comparison investigations of some properties of the Mo-Cu, Mo-Ni(Co)-Cu materials and the W-Cu, W-Ni-Cu compositions used at the present time as well as contact pairs prepared from them is conducted. It is shown that electroerosion wear of the contacts is connected not only with the material properties but also with features of structural changes in the working layer under effect of arc discharge. It is shown also that directed alloying with respect to the origin of phase transition in the electrode material and the medium effect during current commutation promotes electroerosion resistance.

  16. Microstructure and mechanical behavior of metal injection molded Ti-Nb binary alloys as biomedical material.

    Science.gov (United States)

    Zhao, Dapeng; Chang, Keke; Ebel, Thomas; Qian, Ma; Willumeit, Regine; Yan, Ming; Pyczak, Florian

    2013-12-01

    The application of titanium (Ti) based biomedical materials which are widely used at present, such as commercially pure titanium (CP-Ti) and Ti-6Al-4V, are limited by the mismatch of Young's modulus between the implant and the bones, the high costs of products, and the difficulty of producing complex shapes of materials by conventional methods. Niobium (Nb) is a non-toxic element with strong β stabilizing effect in Ti alloys, which makes Ti-Nb based alloys attractive for implant application. Metal injection molding (MIM) is a cost-efficient near-net shape process. Thus, it attracts growing interest for the processing of Ti and Ti alloys as biomaterial. In this investigation, metal injection molding was applied to the fabrication of a series of Ti-Nb binary alloys with niobium content ranging from 10wt% to 22wt%, and CP-Ti for comparison. Specimens were characterized by melt extraction, optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Titanium carbide formation was observed in all the as-sintered Ti-Nb binary alloys but not in the as-sintered CP-Ti. Selected area electron diffraction (SAED) patterns revealed that the carbides are Ti2C. It was found that with increasing niobium content from 0% to 22%, the porosity increased from about 1.6% to 5.8%, and the carbide area fraction increased from 0% to about 1.8% in the as-sintered samples. The effects of niobium content, porosity and titanium carbides on mechanical properties have been discussed. The as-sintered Ti-Nb specimens exhibited an excellent combination of high tensile strength and low Young's modulus, but relatively low ductility.

  17. Microstructure and mechanical behavior of metal injection molded Ti-Nb binary alloys as biomedical material.

    Science.gov (United States)

    Zhao, Dapeng; Chang, Keke; Ebel, Thomas; Qian, Ma; Willumeit, Regine; Yan, Ming; Pyczak, Florian

    2013-12-01

    The application of titanium (Ti) based biomedical materials which are widely used at present, such as commercially pure titanium (CP-Ti) and Ti-6Al-4V, are limited by the mismatch of Young's modulus between the implant and the bones, the high costs of products, and the difficulty of producing complex shapes of materials by conventional methods. Niobium (Nb) is a non-toxic element with strong β stabilizing effect in Ti alloys, which makes Ti-Nb based alloys attractive for implant application. Metal injection molding (MIM) is a cost-efficient near-net shape process. Thus, it attracts growing interest for the processing of Ti and Ti alloys as biomaterial. In this investigation, metal injection molding was applied to the fabrication of a series of Ti-Nb binary alloys with niobium content ranging from 10wt% to 22wt%, and CP-Ti for comparison. Specimens were characterized by melt extraction, optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Titanium carbide formation was observed in all the as-sintered Ti-Nb binary alloys but not in the as-sintered CP-Ti. Selected area electron diffraction (SAED) patterns revealed that the carbides are Ti2C. It was found that with increasing niobium content from 0% to 22%, the porosity increased from about 1.6% to 5.8%, and the carbide area fraction increased from 0% to about 1.8% in the as-sintered samples. The effects of niobium content, porosity and titanium carbides on mechanical properties have been discussed. The as-sintered Ti-Nb specimens exhibited an excellent combination of high tensile strength and low Young's modulus, but relatively low ductility. PMID:23994942

  18. Handbook on Lead-bismuth Eutectic Alloy and Lead Properties, Materials Compatibility, Thermal-hydraulics and Technologies - 2015 Edition

    International Nuclear Information System (INIS)

    Heavy liquid metals such as lead or lead-bismuth have been proposed and investigated as coolants for fast reactors since the 1950's. More recently, there has been renewed interest worldwide in the use of these materials to support the development of systems for the transmutation of radioactive waste. Heavy liquid metals are also under evaluation as a reactor core coolant and accelerator-driven system neutron spallation source. Several national and international R and D programmes are ongoing for the development of liquid lead-alloy technology and the design of liquid lead-alloy-cooled reactor systems. In 2007, a first edition of the handbook was published to provide deeper insight into the properties and experimental results in relation to lead and lead-bismuth eutectic technology and to establish a common database. This handbook remains a reference in the field and is a valuable tool for designers and researchers with an interest in heavy liquid metals. The 2015 edition includes updated data resulting from various national and international R and D programmes and contains new experimental data to help understand some important phenomena such as liquid metal embrittlement and turbulent heat transfer in a fuel bundle. The handbook provides an overview of liquid lead and lead-bismuth eutectic properties, materials compatibility and testing issues, key aspects of thermal-hydraulics and existing facilities, as well as perspectives for future R and D. (authors)

  19. Composite materials based on porous ceramic preform infiltrated by aluminium alloy

    OpenAIRE

    Nagel, A.; A. J. Nowak; M. Kremzer; L.A. Dobrzański

    2007-01-01

    Purpose: The goal of this project is the optimization of manufacturing technology of the ceramic preforms basedon Al2O3 powder manufactured by the pressure infiltration method with liquid metal alloy.Design/methodology/approach: Ceramic preforms were manufactured by the method of sintering of ceramicpowder. The preform material consists of powder Condea Al2O3 CL 2500, however, as the forming factor ofthe structure of canals and pores inside the ceramic agglomerated framework the carbon fibers...

  20. SAW surfacing of low-alloyed steel with super-ferrite additional material

    OpenAIRE

    Klimpel, A; T. Kik; J. Górka; A. Czupryński; P. Sitarz

    2009-01-01

    Purpose: of these researches was to investigate influence of heat input in SAW surfacing of low-alloyed steel with super-ferrite filler material on quality of deposits.Design/methodology/approach: the quality of single and multilayer, stringer beads was assessed by metallographic examinations, stresses measurements and hardness tests.Findings: due to the fact that it was used at automated surfacing stand, the analysis of properties of the deposits was performed for single and multilayer, str...

  1. Investigation of Material Performance Degradation for High-Strength Aluminum Alloy Using Acoustic Emission Method

    Directory of Open Access Journals (Sweden)

    Yibo Ai

    2015-02-01

    Full Text Available Structural materials damages are always in the form of micro-defects or cracks. Traditional or conventional methods such as micro and macro examination, tensile, bend, impact and hardness tests can be used to detect the micro damage or defects. However, these tests are destructive in nature and not in real-time, thus a non-destructive and real-time monitoring and characterization of the material damage is needed. This study is focused on the application of a non-destructive and real-time acoustic emission (AE method to study material performance degradation of a high-strength aluminum alloy of high-speed train gearbox shell. By applying data relative analysis and interpretation of AE signals, the characteristic parameters of materials performance were achieved and the failure criteria of the characteristic parameters for the material tensile damage process were established. The results show that the AE method and signal analysis can be used to accomplish the non-destructive and real-time detection of the material performance degradation process of the high-strength aluminum alloy. This technique can be extended to other engineering materials.

  2. Mechatronic systems and materials III

    CERN Document Server

    Gosiewski, Zdzislaw

    2009-01-01

    This very interesting volume is divided into 24 sections; each of which covers, in detail, one aspect of the subject-matter: I. Industrial robots; II. Microrobotics; III. Mobile robots; IV. Teleoperation, telerobotics, teleoperated semi-autonomous systems; V. Sensors and actuators in mechatronics; VI. Control of mechatronic systems; VII. Analysis of vibration and deformation; VIII. Optimization, optimal design; IX. Integrated diagnostics; X. Failure analysis; XI. Tribology in mechatronic systems; XII. Analysis of signals; XIII. Measurement techniques; XIV. Multifunctional and smart materials;

  3. Digestive ripening: a synthetic method par excellence for core-shell, alloy, and composite nanostructured materials

    Indian Academy of Sciences (India)

    Srilakshmi P Bhaskar; Balaji R Jagirdar

    2012-11-01

    The solvated metal atom dispersion (SMAD) method has been used for the synthesis of colloids of metal nanoparticles. It is a top-down approach involving condensation of metal atoms in low temperature solvent matrices in a SMADreactor maintained at 77 K.Warming of the matrix results in a slurry ofmetal atoms that interact with one another to form particles that grow in size. The organic solvent solvates the particles and acts as a weak capping agent to halt/slow down the growth process to a certain extent. This as-prepared colloid consists of metal nanoparticles that are quite polydisperse. In a process termed as digestive ripening, addition of a capping agent to the as-prepared colloid which is polydisperse renders it highly monodisperse either under ambient or thermal conditions. In this, as yet not well-understood process, smaller particles grow and the larger ones diminish in size until the system attains uniformity in size and a dynamic equilibrium is established. Using the SMAD method in combination with digestive ripening process, highly monodisperse metal, core-shell, alloy, and composite nanoparticles have been synthesized. This article is a review of our contributions together with some literature reports on this methodology to realize various nanostructured materials.

  4. The characteristics of laser welded magnesium alloy using silver nanoparticles as insert material

    Energy Technology Data Exchange (ETDEWEB)

    Ishak, M., E-mail: mahadzir@ump.edu.my [University Malaysia Pahang, Faculty of Mechanical Engineering, 26600 Pekan, Pahang Darul Makmur (Malaysia); Maekawa, K., E-mail: mae@mx.ibaraki.ac.jp [Ibaraki University, Faculty of Engineering, Department of Mechanical Engineering, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Yamasaki, K., E-mail: kyama@mx.ibaraki.ac.jp [Ibaraki University, Faculty of Engineering, Department of Mechanical Engineering, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2012-02-28

    Highlights: Black-Right-Pointing-Pointer Ag nanoparticles are used as insert material for welding Mg alloy with laser. Black-Right-Pointing-Pointer We examine the microstructure and mechanical properties of welded Mg alloys. Black-Right-Pointing-Pointer Nananoparticle promote grain refinement to the weld structure. Black-Right-Pointing-Pointer Finer nanoparticle produces high weld efficiency and mechanical properties. - Abstract: This paper describes the characteristics of the laser welding of thin-sheet magnesium alloys using silver (Ag) nanoparticles as an insert material. The experiment was conducted using nanoparticles with 5 nm and 100 nm diameters that were welded with a Nd:YAG laser. The microstructure and mechanical properties of the specimens welded using inserts with different sizes of nanoparticles and without an insert material, were examined. Electron probe micro-analyzer (EPMA) analysis was conducted to confirm the existence of Ag in the welded area. The introduction of the Ag nanoparticle insert promoted large area of fine grain and broadened the acceptable range of scanning speed parameters compared to welds without an insert. Welds with 5 nm nanoparticles yielded the highest fracture load of up to 818 N while the lowest fracture load was found for weld specimens with 100 nm nanoparticles. This lower fracture load was due to larger voids and a smaller throat length, which contributed to a lower fracture load when using larger nanoparticles.

  5. Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates

    KAUST Repository

    Chen, Tianyou

    2016-05-16

    Transition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.

  6. Thermophysical characterization of Mg–51%Zn eutectic metal alloy: A phase change material for thermal energy storage in direct steam generation applications

    International Nuclear Information System (INIS)

    The possibility of using magnesium based eutectic metal alloys as phase change material (PCM) for thermal energy storage (TES) in concentrated solar power (CSP) applications is analysed. An extensive thermophysical characterization of the Mg–51%Zn eutectic metal alloy between room temperature and melting temperature has been performed. The results are compared with some available data in the literature, and differences found are discussed. A comparison with pure, binary and ternary inorganic salts used as PCM is presented highlighting the advantages and disadvantages of the different systems. This alloy is proposed not only as a candidate for latent heat thermal energy storage for direct steam generation (DSG) in CSP applications but for high pressure and high energy steam processes as well. Reported data are essential for ensuing modelling and experimental reactor studies employing this alloy as a PCM for TES. - Highlights: • Storage material for direct steam generation applications. • Metal alloy as PCM with high thermal conductivity. • Thermal energy storage for high pressure and high energy steam processes

  7. Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

    Science.gov (United States)

    Watanabe, Shoji

    2008-01-01

    This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory. PMID:18075217

  8. Microstructural refinement of hyper-eutectic Al?Si?Fe?Mn cast alloys to produce a recyclable wrought material

    OpenAIRE

    Umezawa, Osamu; Nakamoto, Munefumi; Osawa, Yoshiaki; Suzuki, Kenta; Kumai, Shinji

    2005-01-01

    Although the cascade of material flow is presently suitable for the aluminum recycling, a better utilization of secondary alloys is required. In order to establish an upgradeable recycling design for developing wrought products from secondary aluminum alloys, a fine distribution of the primary phases in hyper-eutectic Al?Si?Fe?Mn cast materials has been achieved. Two novel processes were adopted. One was repeated thermomechanical treatment (RTMT), which involves a repetition of a multi-step c...

  9. Aluminium EN AC-AlSi12 alloy matrix composite materials reinforced by Al2O3 porous preforms

    OpenAIRE

    Nagel, A.; M. Kremzer; L.A. Dobrzański,

    2007-01-01

    Purpose: The purpose of this work is to elaborate the method of manufacturing of composite materials based on porous ceramic preforms infiltrated by eutectic aluminium alloy.Design/methodology/approach: The material for investigations was fabricated by pressure infiltration method of ceramic porous preforms. The eutectic aluminium alloy EN AC – AlSi12 was use as a matrix while as reinforcement were used ceramic preforms fabricated by sintering of Al2O3 Alcoa CL 2500 powder with addition of po...

  10. Shape memory alloys applied to improve rotor-bearing system dynamics - an experimental investigation

    OpenAIRE

    Enemark, Søren; Santos, Ilmar; Marcelo A. Savi

    2015-01-01

    tor-bearing systems have critical speeds and to pass through them is an ongoing challenge in the field of mechanical engineering. The incorporation of shape memory alloys in rotating systems has an increasing importance to improve system performance and to avoid potential damaging situations when passing through critical speeds. In this work, the feasibility of applying shape memory alloys to a rotating system is experimentally investigated. Shape memory alloys can change their stiffness with...

  11. Selection of a Microbiological Corrosion System for Studying Effects on Structural Aluminum Alloys.

    Science.gov (United States)

    Hedrick, H G; Miller, C E; Halkias, J E; Hildebrand, J E

    1964-05-01

    Two laboratory methods, a metal-strip test and a tank test, were evaluated as microbiological corrosion systems for producing corroded test specimens on a structural aluminum alloy. The results show that corrosion of the test alloy occurred best in the metal-strip test in a deionized water-fuel medium inoculated with a mixture of microorganisms under aerated conditions. The metal-strip test was more successful for producing large numbers of corroded test specimens and proved more economical than the tank-type test, since less structural material is needed to obtain a specimen with sufficient corrosion areas, and since the corrosion can more easily be restricted by maskants to certain areas for specific test purposes. PMID:16349646

  12. Effects of graphite on Zn-Sb alloys as anode materials for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The electrochemical properties of multiphases Zn4Sb3C7 and ZnSbC2 as new lithium-ion anode materials wereinvestigated. The composition and microstructures of these multiphase materials were analyzed by XRD and TEM. It wasfound that the addition of graphite modifies the microstructures of pure alloys. The capacities and the cycle stability of theanodes are greatly improved. The reversible capacity of Zn4Sb3C7 reaches as high as 510 mAh/g at the first cycle, andkeeps higher than 300 mAh/g after 10 charge/discharge cycles

  13. System and method of forming nanostructured ferritic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dial, Laura Cerully; DiDomizio, Richard; Alinger, Matthew Joseph; Huang, Shenyan

    2016-07-26

    A system for mechanical milling and a method of mechanical milling are disclosed. The system includes a container, a feedstock, and milling media. The container encloses a processing volume. The feedstock and the milling media are disposed in the processing volume of the container. The feedstock includes metal or alloy powder and a ceramic compound. The feedstock is mechanically milled in the processing volume using metallic milling media that includes a surface portion that has a carbon content less than about 0.4 weight percent.

  14. Dead lithium phase investigation of Sn-Zn alloy as anode materials for lithium ion battery

    Institute of Scientific and Technical Information of China (English)

    HUANG ZhaoWen; HU SheJun; HOU XianHua; RU Qiang; YU HongWen; ZHAO LingZhi; LI WeiShan

    2009-01-01

    In this work, based on First-principle plane wave pseudo-potential method, we have carried out an in-depth study on the possible dead lithium phase of Sn-Zn alloy as anode materials for lithium ion batteries. Through investigation, we found that the phases LixSn4Zn4(x = 2, 4, 6, 8) contributed to reversible capacity, while the phases LixSn4Zns-(x-4)(x = 4.74, 7.72) led to capacity loss due to high formation energy, namely, they were the dead lithium phases during the charge/discharge process. And we come up with a new idea that stable lithium alloy phase with high lithiation formation energy (dead lithium phase) can also result in high loss of active lithium ion, besides the traditional expression that the formation of solid electrolyte interface film leads to high capacity loss.

  15. Mechanical Alloying Synthesis of Co9S8 Particles as Materials for Supercapacitors

    Directory of Open Access Journals (Sweden)

    Bo Li

    2016-06-01

    Full Text Available Cobalt sulfide (Co9S8 particles are compounded as the electrode materials of supercapacitors by a mechanical alloying method. They show excellent properties including good cycling stability and high specific capacitance. A supercapacitor is assembled using Co9S8 as the anode and activated carbon (AC as the cathode. It gains a maximum specific capacitance of 55 F·g−1 at a current density of 0.5 A·g−1, and also an energy density of 15 Wh·kg−1. Those results show that the novel and facile synthetic route may be able to offer a new way to synthesize alloy compounds with excellent supercapacitive properties.

  16. Modeling of Stress Development During Thermal Damage Healing in Fiber-reinforced Composite Materials Containing Embedded Shape Memory Alloy Wires

    NARCIS (Netherlands)

    Bor, T.C.; Warnet, L.; Akkerman, R.; Boer, de A.

    2010-01-01

    Fiber-reinforced composite materials are susceptible to damage development through matrix cracking and delamination. This article concerns the use of shape memory alloy (SMA) wires embedded in a composite material to support healing of damage through a local heat treatment. The composite material co

  17. Alloys in energy development

    International Nuclear Information System (INIS)

    The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems

  18. Nuclear Systems Materials Handbook. [Materials requirements for nuclear energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Marchbanks, M.F; Moen, R.A.; Irvin, J.E.

    1976-01-01

    The NSM Handbook is a multi-volume document being compiled on a continuing basis to meet the broad materials data requirements of those involved in the development of advanced nuclear energy systems. The present focus of the Handbook is upon nuclear systems that have not yet achieved commercial status, with near-term emphasis on the nation's Liquid Metal Fast Breeder Reactor Program. Actual use of the Handbook extends to other advanced nuclear concepts sharing the same needs, and to many nonnuclear engineering activities as well.

  19. An investigation on the effects of phase change material on material components used for high temperature thermal energy storage system

    Science.gov (United States)

    Kim, Taeil; Singh, Dileep; Zhao, Weihuan; Yua, Wenhua; France, David M.

    2016-05-01

    The latent heat thermal energy storage (LHTES) systems for concentrated solar power (CSP) plants with advanced power cycle require high temperature phase change materials (PCMs), Graphite foams with high thermal conductivity to enhance the poor thermal conductivity of PCMs. Brazing of the graphite foams to the structural metals of the LHTES system could be a method to assemble the system and a method to protect the structural metals from the molten salts. In the present study, the LHTES prototype capsules using MgCl2-graphite foam composites were assembled by brazing and welding, and tested to investigate the corrosion attack of the PCM salt on the BNi-4 braze. The microstructural analysis showed that the BNi-4 braze alloy can be used not only for the joining of structure alloy to graphite foams but also for the protecting of structure alloy from the corrosion by PCM.

  20. Calibration and Finite Element Implementation of an Energy-Based Material Model for Shape Memory Alloys

    Science.gov (United States)

    Junker, Philipp; Hackl, Klaus

    2016-06-01

    Numerical simulations are a powerful tool to analyze the complex thermo-mechanically coupled material behavior of shape memory alloys during product engineering. The benefit of the simulations strongly depends on the quality of the underlying material model. In this contribution, we discuss a variational approach which is based solely on energetic considerations and demonstrate that unique calibration of such a model is sufficient to predict the material behavior at varying ambient temperature. In the beginning, we recall the necessary equations of the material model and explain the fundamental idea. Afterwards, we focus on the numerical implementation and provide all information that is needed for programing. Then, we show two different ways to calibrate the model and discuss the results. Furthermore, we show how this model is used during real-life industrial product engineering.

  1. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W.

    1996-06-01

    The objective of the research is to provide databases and design criteria to assist in the selection of optimum alloys for construction of components needed to contain process streams in advanced heat recovery and hot-gas cleanup systems. Typical components include: steam line piping and superheater tubing for low emission boilers (600 to 700{degrees}C), heat exchanger tubing for advanced steam cycles and topping cycle systems (650 to 800{degrees}C), foil materials for recuperators, on advanced turbine systems (700 to 750{degrees}C), and tubesheets for barrier filters, liners for piping, cyclones, and blowback system tubing for hot-gas cleanup systems (850 to 1000{degrees}C). The materials being examined fall into several classes, depending on which of the advanced heat recovery concepts is of concern. These classes include martensitic steels for service to 650{degrees}C, lean stainless steels and modified 25Cr-30Ni steels for service to 700{degrees}C, modified 25Cr-20Ni steels for service to 900{degrees}C, and high Ni-Cr-Fe or Ni-Cr-Co-Fe alloys for service to 1000{degrees}C.

  2. Implants for surgery -- Metallic materials -- Part 3: Wrought titanium 6-aluminium 4-vanadium alloy

    CERN Document Server

    International Organization for Standardization. Geneva

    1996-01-01

    Specifies the characteristics of, and corresponding test methods for, the wrought titanium alloy known as titanium 6-aluminium 4-vanadium alloy (Ti 6-Al 4-V alloy) for use in the manufacture of surgical implants.

  3. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X N; Zhou, W R; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Li, X L [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Cheng, Y, E-mail: yfzheng@pku.edu.c [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2010-06-01

    Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s{sup -1}, 30 m s{sup -1} and 45 m s{sup -1}) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 {mu}m) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr{sup -1} for RS15, 0.94 mm yr{sup -1} for RS30 and 0.36 mm yr{sup -1} for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

  4. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material.

    Science.gov (United States)

    Gu, X N; Li, X L; Zhou, W R; Cheng, Y; Zheng, Y F

    2010-06-01

    Rapidly solidified (RS) Mg–3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s(-1), 30 m s(-1) and 45 m s(-1) with the as-cast Mg–3Ca alloy ingot as a raw material. The RS45 Mg–3Ca alloy ribbon showed a much more fine grain size feature (approximately 200–500 nm) in comparison to the coarse grain size (50–100 μm)of the original as-cast Mg–3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg–3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds(1.43 mm yr(-1) for RS15, 0.94 mm yr(-1) for RS30 and 0.36 mm yr(-1) for RS45). The RS Mg–3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg–3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg–3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells,whereas the as-cast Mg–3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg–3Ca alloy ribbons than that of the as-cast Mg–3Ca alloy ingot.

  5. Microstructural investigation of uranium rich U-Zr-Nb ternary alloy system

    Science.gov (United States)

    Ghoshal, Kaushik; Kaity, Santu; Mishra, Sudhir; Kumar, Arun

    2014-03-01

    Uranium rich U-Zr-Nb alloy system is a potential candidate among the family of alloys considered as metallic fuel for fast reactors application. As a part of the program U-7% Zr, U-5% Zr-2% Nb, U-3.5% Zr-3.5% Nb, U-2% Zr-5% Nb and U-7% Nb (composition in wt.%) alloys were prepared. The total amount of Nb and Zr was restricted, because higher addition of non-fissile alloying element not only reduces the fissile content it also decreases the breeding ratio due to parasitic absorption. The alloys were characterized by SEM micrograph. The phase analysis was performed with the help of XRD and the phase transformation temperatures were determined by DTA. The variation in crystal structure with subsequent replacement of Zr with Nb as an alloying element has been highlighted. The as quenched U-7% Nb alloy shows complete γ° phase at ambient temperature.

  6. Supercapacitors materials, systems and applications

    CERN Document Server

    Lu, Max; Frackowiak, Elzbieta

    2013-01-01

    Written by an international group of leading experts from both academia and industry, this is the first comprehensive book on the topic for 10 years. Taking into account the commercial interest in these systems and the scientific and technological developments over the past decade, all important materials and systems are covered, with several chapters devoted to topics of direct industrial relevance.The book starts by providing an introduction to the general principles of electrochemistry, the properties of electrochemical capacitors, and electrochemical characterization techniques. There

  7. Yield Asymmetry Design of Magnesium Alloys by Integrated Computational Materials Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongsheng; Joshi, Vineet V.; Lavender, Curt A.; Khaleel, Mohammad A.; Ahzi, Said

    2013-11-01

    Deformation asymmetry of magnesium alloys is an important factor on machine design in automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to microstructure, characterized by texture and grain size. Modified intermediate phi-model, a polycrystalline viscoplasticity model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry by thermomechanical processing. In some texture, for example, rolled texture, CYS/TYS is smaller than 1 under different loading directions. In some texture, for example, extruded texture, asymmetry is large along normal direction. Starting from rolled texture, the asymmetry will increased to close to 1 along rolling direction after compressed to a strain of 0.2. Our model shows that grain refinement increases CYS/TYS. Besides texture control, grain refinement can also optimize the yield asymmetry. After the grain size decreased to a critical value, CYS/TYS reaches to 1 since CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.

  8. Materials Compatibility of HVACR System Materials with Low GWP Refrigerants

    OpenAIRE

    Majurin, Julie A.; Gilles, William; Staats, Steven J.

    2014-01-01

    When assessing the suitability of next generation refrigerants for use with current HVACR system materials, two areas of concern need to be thoroughly investigated and understood: 1) chemical stability of the fluids when exposed to system materials under the anticipated conditions of use, and 2) compatibility of the system materials when in contact with the fluids. This paper will summarize materials compatibility evaluations of unsaturated hydrofluorocarbon (HFO) refrigerants, and HFO refrig...

  9. Ballistic impact properties of mixed multi-layered amorphous surface alloyed materials fabricated by high-energy electron-beam irradiation

    International Nuclear Information System (INIS)

    The objective of this study is to investigate ballistic impact properties of multi-layered amorphous surface alloyed materials fabricated by high-energy electron-beam irradiation. The mixture of Zr-based amorphous alloy powders and LiF+MgF2 flux powders was deposited on a Ti alloy substrate, and then electron beam was irradiated on this powder mixture to fabricate an one-layered surface alloyed material. On top of this layer, the powder mixture was deposited again and then irradiated with electron beam whose beam current was decreased to fabricate the multi-layered surface alloyed material. In the mixed multi-layered surface alloyed materials fabricated with LM1 alloy powders and LM2 or LM10 alloy powders, the surface region consisted of amorphous phases, together with a small amount of crystalline particles, whereas the center region was complicatedly composed of amorphous phases, crystallized phases, and dendritic β phases. Since the surface region mostly composed of amorphous matrix was quite hard, the alloyed materials sufficiently blocked the travel of a projectile. When cracks formed at the surface region propagated into the center region, the formation of many cracks or debris was accelerated, which could beneficially work for absorbing the ballistic impact energy, thereby leading to the higher ballistic impact properties than the surface alloyed materials fabricated with LM1 or LM2 alloy powders

  10. Corrosion of structural materials for Generation IV systems

    International Nuclear Information System (INIS)

    The Generation IV International Forum aims at developing future generation nuclear energy systems. Six systems have been selected for further consideration: sodium-cooled fast reactor (SFR), gas-cooled fast reactor (GFR), lead-cooled fast reactor (LFR), molten salt reactor (MSR), supercritical water-cooled reactor (SCWR) and very high temperature reactor (VHTR). CEA, in the frame of a national program, of EC projects and of the GIF, contributes to the structural materials developments and research programs. Particularly, corrosion studies are being performed in the complex environments of the GEN IV systems. As a matter of fact, structural materials encounter very severe conditions regarding corrosion concerns: high temperatures and possibly aggressive chemical environments. Therefore, the multiple environments considered require also a large diversity of materials. On the other hand, the similar levels of working temperatures as well as neutron spectrum imply also similar families of materials for the various systems. In this paper, status of the research performed in CEA on the corrosion behavior of the structural material in the different environments is presented. The materials studied are either metallic materials as austenitic (or Y, La, Ce doped) and ferrito-martensitic steels, Ni base alloys, ODS steels, or ceramics and composites. In all the environments studied, the scientific approach is identical, the objective being in all cases the understanding of the corrosion processes to establish recommendations on the chemistry control of the coolant and to predict the long term behavior of the materials by the development of corrosion models. (author)

  11. Crevice corrosion resistance of high alloyed materials in 3.5 % NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Alar, Vesna; Stojanovic, Ivan; Simunovic, Vinko [Zagreb Univ. (Croatia). Faculty of Mechanical Engineering and Naval Architecture; Novak, Tomislav [NMP Produkt Ltd., Nedelisce (Croatia)

    2014-06-15

    The effects of applied torque on the corrosion behaviour of W.-Nr. 1.4404 and 1.4462 stainless steels and W.-Nr. 2.4605 and 2.4858 nickel alloys with crevices were investigated using the cyclic potentiodynamic polarization method. Crevice corrosion (material-to-polytetrafluoroethylene) was tested in 3.5 % NaCl solution at 22 C. The corroded surface was examined using scanning electron microscopy. The results indicate similar trends in susceptibility to crevice corrosion with increasing torque. Among the four specimens, the W.-Nr. 1.4404 is the most susceptible to crevice corrosion. (orig.)

  12. Optimized constitutive equation of material property based on inverse modeling for aluminum alloy hydroforming simulation

    Institute of Scientific and Technical Information of China (English)

    LANG Li-hui; LI Tao; ZHOU Xian-bin; B. E. KRISTENSEN; J. DANCKERT; K. B. NIELSEN

    2006-01-01

    By using aluminum alloys, the properties of the material in sheet hydroforming were obtained based on the identification of parameters for constitutive models by inverse modeling in which the friction coefficients were also considered in 2D and 3D simulations. With consideration of identified simulation parameters by inverse modeling, some key process parameters including tool dimensions and pre-bulging on the forming processes in sheet hydroforming were investigated and optimized. Based on the optimized parameters, the sheet hydroforming process can be analyzed more accurately to improve the robust design. It proves that the results from simulation based on the identified parameters are in good agreement with those from experiments.

  13. Computational Analysis of Material Flow During Friction Stir Welding of AA5059 Aluminum Alloys

    Science.gov (United States)

    Grujicic, M.; Arakere, G.; Pandurangan, B.; Ochterbeck, J. M.; Yen, C.-F.; Cheeseman, B. A.; Reynolds, A. P.; Sutton, M. A.

    2012-09-01

    Workpiece material flow and stirring/mixing during the friction stir welding (FSW) process are investigated computationally. Within the numerical model of the FSW process, the FSW tool is treated as a Lagrangian component while the workpiece material is treated as an Eulerian component. The employed coupled Eulerian/Lagrangian computational analysis of the welding process was of a two-way thermo-mechanical character (i.e., frictional-sliding/plastic-work dissipation is taken to act as a heat source in the thermal-energy balance equation) while temperature is allowed to affect mechanical aspects of the model through temperature-dependent material properties. The workpiece material (AA5059, solid-solution strengthened and strain-hardened aluminum alloy) is represented using a modified version of the classical Johnson-Cook model (within which the strain-hardening term is augmented to take into account for the effect of dynamic recrystallization) while the FSW tool material (AISI H13 tool steel) is modeled as an isotropic linear-elastic material. Within the analysis, the effects of some of the FSW key process parameters are investigated (e.g., weld pitch, tool tilt-angle, and the tool pin-size). The results pertaining to the material flow during FSW are compared with their experimental counterparts. It is found that, for the most part, experimentally observed material-flow characteristics are reproduced within the current FSW-process model.

  14. Laser Welding Characterization of Kovar and Stainless Steel Alloys as Suitable Materials for Components of Photonic Devices Packaging

    Science.gov (United States)

    Fadhali, M. M. A.; Zainal, Saktioto J.; Munajat, Y.; Jalil, A.; Rahman, R.

    2010-03-01

    The weldability of Kovar and stainless steel alloys by Nd:YAG laser beam is studied through changing of some laser beam parameters. It has been found that there is a suitable interaction of the pulsed laser beam of low power laser pulse with both the two alloys. The change of thermophysical properties with absorbed energy from the laser pulse is discussed in this paper which reports the suitability of both Kovar and stainless steel 304 as the base materials for photonic devices packaging. We used laser weld system (LW4000S from Newport) which employs Nd:YAG laser system with two simultaneous beams output for packaging 980 nm high power laser module. Results of changing both laser spot weld width and penetration depth with changing both the pulse peak power density, pulse energy and pulse duration show that there are good linear relationships between laser pulse energy or peak power density and pulse duration with laser spot weld dimensions( both laser spot weld width and penetration depth). Therefore we concluded that there should be an optimization for both the pulse peak power and pulse duration to give a suitable aspect ratio (laser spot width to penetration depth) for achieving the desired welds with suitable penetration depth and small spot width. This is to reduce the heat affected zone (HAZ) which affects the sensitive optical components. An optimum value of the power density in the order of 105 w/cm2 found to be suitable to induce melting in the welded joints without vaporization. The desired ratio can also be optimized by changing the focus position on the target material as illustrated from our measurements. A theoretical model is developed to simulate the temperature distribution during the laser pulse heating and predict the penetration depth inside the material. Samples have been investigated using SEM with EDS. The metallographic measurements on the weld spot show a suitable weld yield with reasonable weld width to depth ratio.

  15. Effect of thione primers on adhesive bonding between an indirect composite material and Ag-Pd-Cu-Au alloy.

    Science.gov (United States)

    Imai, Hideyuki; Koizumi, Hiroyasu; Shimoe, Saiji; Hirata, Isao; Matsumura, Hideo; Nikawa, Hiroki

    2014-01-01

    The current study evaluated the effect of primers on the shear bond strength of an indirect composite material joined to a silverpalladium-copper-gold (Ag-Pd-Cu-Au) alloy (Castwell). Disk specimens were cast from the alloy and were air-abraded with alumina. Eight metal primers were applied to the alloy surface. A light-polymerized indirect composite material (Solidex) was bonded to the alloy. Shear bond strength was determined both before and after the application of thermocycling. Two groups primed with Metaltite (thione) and M. L. Primer (sulfide) showed the greatest post-thermocycling bond strength (8.8 and 6.5 MPa). The results of the X-ray photoelectron spectroscopic (XPS) analysis suggested that the thione monomer (MTU-6) in the Metaltite primer was strongly adsorbed onto the Ag-Pd-Cu-Au alloy surface even after repeated cleaning with acetone. The application of either the thione (MTU-6) or sulfide primer is effective for enhancing the bonding between a composite material and Ag-Pd-Cu-Au alloy.

  16. Smart Materials for Ranging Systems

    CERN Document Server

    Franse, Jaap; Sirenko, Valentyna

    2006-01-01

    The problem of determining the location of an object (usually called ranging) attracts at present much attention in different areas of applications, among them in ecological and safety devices. Electromagnetic waves along with sound waves are widely used for these purposes. Different aspects of materials with specific magnetic, electric and elastic properties are considered in view of potential application in the design and manufacturing of smart materials. Progress is reported in the fabrication and understanding of in-situ formation and characterization of solid state structures with specified properties. Attention is paid to the observation and study of the mobility of magnetic structures and of the kinetics of magnetic ordering transitions. Looking from a different perspective, one of the outcomes of the ARW is the emphasis on the important role that collective phenomena (like spin waves in systems with a magnetically ordered ground state, or critical currents in superconductors) could play at the design ...

  17. Material control system simulator program reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Hollstien, R.B.

    1978-01-24

    A description is presented of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts. Although MCSS may be used independently in the design or analysis of material handling and processing systems, it has been tailored toward the determination of material accountability and the response of material control systems to adversary action sequences.

  18. Materials Properties Database for Selection of High-Temperature Alloys and Concepts of Alloy Design for SOFC Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z Gary; Paxton, Dean M.; Weil, K. Scott; Stevenson, Jeffry W.; Singh, Prabhakar

    2002-11-24

    To serve as an interconnect / gas separator in an SOFC stack, an alloy should demonstrate the ability to provide (i) bulk and surface stability against oxidation and corrosion during prolonged exposure to the fuel cell environment, (ii) thermal expansion compatibility with the other stack components, (iii) chemical compatibility with adjacent stack components, (iv) high electrical conductivity of the surface reaction products, (v) mechanical reliability and durability at cell exposure conditions, (vii) good manufacturability, processability and fabricability, and (viii) cost effectiveness. As the first step of this approach, a composition and property database was compiled for high temperature alloys in order to assist in determining which alloys offer the most promise for SOFC interconnect applications in terms of oxidation and corrosion resistance. The high temperature alloys of interest included Ni-, Fe-, Co-base superal

  19. Properties and Potential of Two (ni,pt)ti Alloys for Use as High-temperature Actuator Materials

    Science.gov (United States)

    Noebe, Ronald; Gaydosh, Darrell; Padula, Santo, II.; Garg, Anita; Biles, Tiffany; Nathal, Michael

    2005-01-01

    The microstructure, transformation temperatures, basic tensile properties, shape memory behavior, and work output for two (Ni,Ti)Pt high-temperature shape memory alloys have been characterized. One was a Ni30Pt20Ti50 alloy (referred to as 20Pt) with transformation temperatures above 230 C and the other was a Ni20Pt30Ti50 alloy (30Pt) with transformation temperatures about 530 C. Both materials displayed shape memory behavior and were capable of 100% (no-load) strain recovery for strain levels up to their fracture limit (3-4%) when deformed at room temperature. For the 20Pt alloy, the tensile strength, modulus, and ductility dramatically increased when the material was tested just about the austenite finish (A(sub f)) temperature. For the 30Pt alloy, a similar change in yield behavior at temperatures above the A(sub f) was not observed. In this case the strength of the austentite phase was at best comparable and generally much weaker than the martensite phase. A ductility minimum was also observed just below the A(sub s) temperature in this alloy. As a result of these differences in tensile behavior, the two alloys performed completely different when thermally cycled under constant load. The 20Pt alloy behaved similar to conventional binary NiTi alloys with work output due to the martensite-to-austenite transformation initially increasing with applied stress. The maximum work output measured in the 20Pt alloy was nearly 9 J/cu cm and was limited by the tensile ductility of the material. In contrast, the martensite-to-austenite transformation in the 30Pt alloy was not capable of performing work against any bias load. The reason for this behavior was traced back to its basic mechanical properties, where the yield strength of the austenite phase was similar to or lower than that of the martensite phase, depending on temperature. Hence, the recovery or transformation strain for the 30Pt alloy under load was essentially zero, resulting in zero work output.

  20. LABORATORY SYSTEM FOR INVESTIGATION OF FATIGUE DEGRADATION IN FERROMAGNETIC MATERIALS AND EXAMPLES OF ITS IMPLEMENTATION

    Directory of Open Access Journals (Sweden)

    V. N. Busko

    2012-01-01

    Full Text Available Shows the block diagram of the laboratory system for investigation of fatigue degradation in ferromagnetic materials by method of magnetic noise. Describes the principle operation of the system, given the practical results its using in assessment of the degree fatigue degradation in ferromagnetic structural steels and alloys on the basis of cyclic testing and measuring the intensity of the magnetic noise.

  1. Corrosion phenomena of alloys and electrode materials in molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Biedenkopf, P. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Werkstoffe und Verfahren der Energietechnik; Bischoff, M.M. [MTU-Friedrichshafen GmbH, - Neue Technologien - ZEB -, Muenchen (Germany); Wochner, T. [MTU-Friedrichshafen GmbH, Abt. TQZ, Friedrichshafen (Germany)

    2000-05-01

    The corrosion behavior of different alloys and the electrical conductivity of the growing corrosion scales was investigated under simulated and real molten carbonate fuel cell conditions. The corrosion of the usually used NiO cathode material was also investigated. In several exposure tests in oxidizing atmospheres, the FeCrMnNi steel 1.3965 showed a higher corrosion resistance to the aggressive carbonate media than the FeCrNi alloy 1.4404 (SS316L). This superior corrosion resistance is explained by the formation of a mixed (Fe,Ni,Mn){sub x}Cr{sub 3-x}O{sub 4} spinel layer, which reduces the outward diffusion of iron ions more than the mixed (Fe,Ni)Cr{sub 2}O{sub 4} spinel formed on austenitic FeCrNi steels. Oxide debris, which spalls off the current collectors, was investigated by XRD. The corrosion scales spalled off mainly at the curved area of the current collector and not at the cathode/current collector interface. The debris was strongly magnetic and consisted of several, in some cases lithiated iron oxides, whereby {alpha}-Fe{sub 2}O{sub 3} (hematite), {gamma}-Fe{sub 2}O{sub 3} (maghemite) and Fe{sub 3}O{sub 4} (magnetite) formed most of the debris. The investigations of the electrical conductivity of the corrosion scales have shown that the electrical conductivity is limited by the inner, Cr-containing oxide of the multi-layered corrosion scale. Cr-rich alloys which contain more than 20 wt.% Cr showed extremely high ohmic resistance of the corrosion scale, much higher than that of alloys containing less than 20 wt.% Cr due to the formation of highly conductive mixed spinel layers. Small additions of Al in the alloy increased the ohmic resistance of the corrosion scale by many orders of magnitude. Corrosion tests in the fuel environment showed, that common uncoated stainless steels are not suitable for the use as anodic current collectors.

  2. Shape memory alloy microvalves for a fluidic control system

    Science.gov (United States)

    Megnin, Christof; Kohl, Manfred

    2014-02-01

    This paper presents the design, fabrication, and performance of shape memory alloy (SMA) microvalves with a novel plug-in interface that enable arbitrary combinations and interchange of individual valve components in order to realize customized fluidic control systems. Actuation of the valves relies on a micromachined SMA foil, which is prestrained in order to adjust for a given flow, and pressure requirement. A demonstrator system is presented consisting of up to nine microvalves, flow channels and control electronics arranged in different functional layers that are stacked onto each other. The microvalves are designed for flow rates of 12.5 ml min-1 (water) in open state at a pressure difference of 200 kPa. Flow regulation is tested in closed-loop control mode using a flow sensor with a short time constant. The accuracy of flow control is in the order of 1.5%. The response times are below 24 ms.

  3. Application Of Shape Memory Alloy In Harvesto-Absorber System

    Directory of Open Access Journals (Sweden)

    Kęcik Krzysztof

    2015-09-01

    Full Text Available This paper presents a conception of the harvester-absorber system consisting of two parts. The first is the pendulum attached to the main system (oscillator, which is suspended on the linear damper and the nonlinear spring made of shape memory alloy. The spring is modelled as a polynomial function based on Landau–Ginzburg theory of phase transitions (similar as ferroelectric and ferromagnets. The obtained results show, that SMA element can increase harvesting energy level, while the absorber effect can be impaired (but not loss. Additionally, introducing SMA element causes changes in dynamics, introduces a new unstable solutions and bifurcations. The analysis was done by classical integration and continuation solution methods.

  4. Heavy ion irradiation effects in Zr excel alloy pressure tube material

    International Nuclear Information System (INIS)

    Zirconium Excel alloy (Zr-3.5wt.%Sn-0.8%Nb-0.8%Mo) is the candidate material for pressure tubes in the Generation-IV CANDU® Super Critical Water-cooled Reactor (SCWR) design. Changes in microstructure induced by neutron irradiation are known to have important consequences on the in-reactor deformation behavior. The in-situ ion irradiation technique has been employed to elucidate the irradiation damage in dual phase Zr-excel alloy (~60% hcp alpha and ~40% bcc beta). 1 MeV Kr ion irradiation experiments were conducted at different temperatures ranging from 100oC-400oC. Damage microstructures have been characterized by Transmission Electron Microscopy in both the alpha and beta phases at different temperatures after a maximum dose of 10 dpa. Several new observations including irradiation induced omega (ω) phase precipitation have been reported. The ω/β orientation relationship was determined by the detailed analysis of selected area diffraction patterns. In-situ irradiation provided an opportunity to observe the nucleation and growth of basal plane c-component loops. It has been shown that under Kr ion irradiation the c-loops start to nucleate and grow above a threshold dose, as has been observed for neutron irradiation. Furthermore, the role of temperature, material composition and pre-irradiation microstructure has been discussed in detail. (author)

  5. Optimisation of the rivet joints of the CFRP composite material and aluminium alloy

    Directory of Open Access Journals (Sweden)

    A. Czulak

    2007-01-01

    Full Text Available Purpose: The project included analysis of strain, cracking, and failure of riveted joints of plate elements madefrom the carbon-fibre-reinforced plastics (CFRP and from the 6061 aluminium alloy.Design/methodology/approach: The modelled static tensile strength test carried out for the plates from CFRPand from the 6061 aluminium alloy joined with the steel rivet. Computer simulation was carried out with IDEASsoftware package employing the FEM.Findings: Simulations using the mesh with a bigger number of FEM elements do not yield better accuracy ofcalculations and do not improve convergence with the results of laboratory experiments. Only the calculationtime gets longer. Computer simulation has also show that the type of contacts employed between elementsaffects the results significantly.Research limitations/implications: For the composite materials, joints between materials and computersimulation examinations are planed.Practical implications: Results obtained for the mesh with 4 and 5 FEM elements are the closest to the resultsof laboratory experiments, which is confirmed by the strain plot. Simulations using the mesh with a biggernumber of FEM elements do not yield better accuracy of calculations and do not improve convergence with theresults of laboratory experiments. Only the calculation time gets longer. Computer simulation has show that thetype of contacts employed between elements affects the results significantly.Originality/value: The paper presents influence of fibre mesh closeness on convergence of the results with laboratorytests. Simulation results were collected and compared with the laboratory static tensile strength tests results.

  6. Length-Scale Effects and Material Models at Numerical Simulations of Nanoindentation of A Metallic Alloy

    Directory of Open Access Journals (Sweden)

    Nikolov N.

    2014-06-01

    Full Text Available Some specially designed metallic alloys crystallize during process of rapid quenching which aims their amorphization. Nevertheless, change in their mechanical properties could be seen compared to these obtained during conventional technological regimes of cooling. That attracts the attention in this elaboration. Full 3-D numerical simulations of nanoindentation process of two material models are performed. The models reflect equivalent elastic and different plastic material properties. The plastic behaviour of the first one is subjected to yield criterion of Dracker-Prager and this of the second one to yield criterion of Mises. The reported numerical results depending on the nanoindentation scale length of 1000 nanometers, suggest different adequacy of the two yield criteria to the data obtained experimentally with a Zr-Al-Cu-Ni-Mo alloy. It could be speculated that the different effects developed depending on the indenter travel of 1000 nanometers and taken into account in the two yield criteria stand behind this fact and determinate three structural levels of plastic deformation.

  7. Material modelling and its application to creep-age forming of aluminium alloy 7B04

    Directory of Open Access Journals (Sweden)

    Lam Aaron C.L.

    2015-01-01

    Full Text Available Creep-ageing behaviour of aluminium alloy 7B04-T651 at 115 °C under a range of tensile stress levels has been experimentally investigated and numerically modelled for creep-age forming (CAF applications. Creep strain, yield strength evolution and precipitate growth of creep-aged specimens were investigated. The alloy was modelled using a set of unified constitutive equations, which captures its creep deformation and takes into account yield strength contributions from three creep-age hardening mechanisms. Applications of the present work are demonstrated by implementing the determined material model into a commercial finite element analysis solver to analyse CAF operations carried out in a novel flexible CAF tool. Stress relaxation, yield strength, precipitate size and springback were predicted for the creep-age formed plates. The predicted springback were further quantified and compared with experimental measurements and a good agreement of 2.5% deviation was achieved. This material model now enables further investigations of 7B04 under various CAF scenarios to be conducted inexpensively via computational modelling.

  8. Evaluation of the Characteristics of the Aluminum Alloy Casting Material by Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Syung Yul; Park, Dong Hyun; Won, Jong Pil; Kim, Yun Hae; Lee, Myung Hoon; Moon, Kyung Man; Jeong, Jae Hyun [Korea Maritime Univ., Busan (Korea, Republic of)

    2012-06-15

    Aluminum is on active metal, but it is well known that its oxide film plays a role as protective barrier which is comparatively stable in air and neutral aqueous solution. Thus, aluminum alloys have been widely applied in architectural trim, cold and hot-water storage vessels and piping etc., furthermore, the aluminum alloy of AC8A have been widely used in mold casting material of engine piston because of its properties of temperature and wear resistance. In recent years, the oil price is getting higher and higher, thus the using of low quality oil has been significantly increased in engines of ship and vehicle. Therefore it is considered that evaluation of corrosion resistance as well as wear resistance of AC8A material is also important to improve its property and prolong its lifetime. In this study, the effect of solution and tempering heat treatment to corrosion and wear resistance is investigated with electrochemical method and measurement of hardness. The hardness decreased with solution heat treatment compared to mold casting condition, but its value increased with tempering heat treatment and exhibited the highest value of hardness with tempering heat treatment temperature at 190 .deg. C for 24hrs. Furthermore, corrosion resistance increased with decreasing of the hardness, and decreased with increasing of the hardness reversely. As a result, it is suggested that the optimum heat treatment to improve both corrosion and wear resistance is tempering heat treatment temperature at 190 .deg. C for 16hrs.

  9. Novel tribological systems using shape memory alloys and thin films

    Science.gov (United States)

    Zhang, Yijun

    Shape memory alloys and thin films are shown to have robust indentation-induced shape memory and superelastic effects. Loading conditions that are similar to indentations are very common in tribological systems. Therefore novel tribological systems that have better wear resistance and stronger coating to substrate adhesion can be engineered using indentation-induced shape memory and superelastic effects. By incorporating superelastic NiTi thin films as interlayers between chromium nitride (CrN) and diamond-like carbon (DLC) hard coatings and aluminum substrates, it is shown that the superelasticity can improve tribological performance and increase interfacial adhesion. The NiTi interlayers were sputter deposited onto 6061 T6 aluminum and M2 steel substrates. CrN and DLC coatings were deposited by unbalanced magnetron sputter deposition. Temperature scanning X-ray diffraction and nanoindentation were used to characterize NiTi interlayers. Temperature scanning wear and scratch tests showed that superelastic NiTi interlayers improved tribological performance on aluminum substrates significantly. The two-way shape memory effect under contact loading conditions is demonstrated for the first time, which could be used to make novel tribological systems. Spherical indents in NiTi shape memory alloys and thin films had reversible depth changes that were driven by temperature cycling, after thermomechanical cycling, or one-cycle slip-plasticity deformation training. Reversible surface topography was realized after the indents were planarized. Micro- and nano- scale circular surface protrusions arose from planarized spherical indents in bulk and thin film NiTi alloy; line surface protrusions appeared from planarized scratch tracks. Functional surfaces with reversible surface topography can potentially result in novel tribological systems with reversible friction coefficient. A three dimensional constitutive model was developed to describe shape memory effects with slip

  10. Novel Concepts for Damage-Resistant Alloys in Next Generation Nuclear Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Stephen M. Bruemmer; Peter L. Andersen; Gary Was

    2002-12-27

    The discovery of a damage-resistant alloy based on Hf solute additions to a low-carbon 316SS is the highlight of the Phase II research. This damage resistance is supported by characterization of radiation-induced microstructures and microchemistries along with measurements of environmental cracking. The addition of Hf to a low-carbon 316SS reduced the detrimental impact of radiation by changing the distribution of Hf. Pt additions reduced the impact of radiation on grain boundary segregation but did not alter its effect on microstructural damage development or cracking. Because cracking susceptibility is associated with several material characteristics, separate effect experiments exploring strength effects using non-irradiated stainless steels were conducted. These crack growth tests suggest that irradiation strength by itself can promote environmental cracking. The second concept for developing damage resistant alloys is the use of metastable precipitates to stabilize the microstructure during irradiation. Three alloys have been tailored for evaluation of precipitate stability influences on damage evolution. The first alloy is a Ni-base alloy (alloy 718) that has been characterized at low neutron irradiation doses but has not been characterized at high irradiation doses. The other two alloys are Fe-base alloys (PH 17-7 and PH 17-4) that have similar precipitate structures as alloy 718 but is more practical in nuclear structures because of the lower Ni content and hence lesser transmutation to He.

  11. Recent developments of the aluminium-lithium system alloys for aircraft uses; Recentes desenvolvimentos das ligas do sistema aluminio-litio para fins aeronauticos

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Marcelo; Plaut, Ronald Lesley

    1992-12-31

    A brief review is made of the latest developments in the production of Aluminium-Lithium alloys. The necessity for new materials in the field of aeronautics has speeded up research on metallic and non-metallic materials. Lately, a good part of the research in the field of metallic components has been directed at Al-Li alloys. More recently, with the development of quaternary alloys Al-Li-X-X, the old problem of low toughness was overcome. The finality of this study is to cover the developments of the mentioned alloys, including the fundamentals of physical metallurgy of the complex system recently developed Al-Li-Cu-Mg. (author) 27 refs., 2 figs., 4 tabs.

  12. NASA-UVA Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft

    Science.gov (United States)

    Starke, E. A., Jr.

    1997-01-01

    This is the final report of the study "Aluminum-Based Materials for High Speed Aircraft" which had the objectives (1) to identify the most promising aluminum-based materials with respect to major structural use on the HSCT and to further develop those materials and (2) to assess the materials through detailed trade and evaluation studies with respect to their structural efficiency on the HSCT. The research team consisted of ALCOA, Allied-Signal, Boeing, McDonnell Douglas, Reynolds Metals and the University of Virginia. Four classes of aluminum alloys were investigated: (1) I/M 2XXX containing Li and I/M 2XXX without Li, (2) I/M 6XXX, (3) two P/M 2XXX alloys, and (4) two different aluminum-based metal matrix composites (MMC). The I/M alloys were targeted for a Mach 2.0 aircraft and the P/M and MMC alloys were targeted for a Mach 2.4 aircraft. Design studies were conducted using several different concepts including skin/stiffener (baseline), honeycomb sandwich, integrally stiffened and hybrid adaptations (conventionally stiffened thin-sandwich skins). Alloy development included fundamental studies of coarsening behavior, the effect of stress on nucleation and growth of precipitates, and fracture toughness as a function of temperature were an integral part of this program. The details of all phases of the research are described in this final report.

  13. Simultaneous material flow analysis of nickel, chromium, and molybdenum used in alloy steel by means of input-output analysis.

    Science.gov (United States)

    Nakajima, Kenichi; Ohno, Hajime; Kondo, Yasushi; Matsubae, Kazuyo; Takeda, Osamu; Miki, Takahiro; Nakamura, Shinichiro; Nagasaka, Tetsuya

    2013-05-01

    Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of materials/substances in supply chains. This study combined a waste input-output material flow model and physical unit input-output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Improvement in EoL sorting technologies and implementation of designs for recycling/disassembly at the manufacturing phase are needed. Possible solutions include development of sorting processes for steel scrap and introduction of easier methods for identifying the composition of secondary resources. Recovery of steel scrap with a high alloy content will reduce primary inputs of alloying elements and contribute to more efficient resource use. PMID:23528100

  14. Design for additive manufacturing of composite materials and potential alloys: a review

    Directory of Open Access Journals (Sweden)

    Hegab Hussien A.

    2016-01-01

    Full Text Available As a first step of applying additive manufacturing (AM technology, plastic prototypes have been produced using various AM Process such as Fusion Deposition Modeling (FDM, Stereolithography (SLA and other processes. After more research and development, AM has become capable of producing complex net shaped in materials which can be used in applicable parts. These materials include metals, ceramics, and composites. Polymers and metals are considered as commercially available materials for AM processes; however, ceramics and composites are still considered under research and development. In this study, a literature review on design for AM of composite materials and potential alloys is discussed. It is investigated that polymer matrix, ceramic matrix, metal matrix, and fiber reinforced are most common composites through AM. Furthermore, Functionally Graded Materials (FGM is considered as an effective application of AM because AM offers the ability to control the composition and optimize the properties of the built part. An example of FGM through using AM technology is the missile nose cone which includes an ultra-high temperature ceramic graded to a refractory metal from outside to inside and it used for sustaining extreme external temperatures. During this work, different applications of AM on different classifications of composite materials are shown through studying of industrial objective, the importance of application, processing, results and future challenges.

  15. Advances in Materials and System Technology for Portable Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram R.

    2007-01-01

    This viewgraph presentation describes the materials and systems engineering used for portable fuel cells. The contents include: 1) Portable Power; 2) Technology Solution; 3) Portable Hydrogen Systems; 4) Direct Methanol Fuel Cell; 5) Direct Methanol Fuel Cell System Concept; 6) Overview of DMFC R&D at JPL; 7) 300-Watt Portable Fuel Cell for Army Applications; 8) DMFC units from Smart Fuel Cell Inc, Germany; 9) DMFC Status and Prospects; 10) Challenges; 11) Rapid Screening of Well-Controlled Catalyst Compositions; 12) Screening of Ni-Zr-Pt-Ru alloys; 13) Issues with New Membranes; 14) Membranes With Reduced Methanol Crossover; 15) Stacks; 16) Hybrid DMFC System; 17) Small Compact Systems; 18) Durability; and 19) Stack and System Parameters for Various Applications.

  16. Carbon-coated Ni 20Si 80 alloy-graphite composite as an anode material for lithium-ion batteries

    Science.gov (United States)

    Lee, Heon-Yong; Kim, Young-Lae; Hong, Moon-Ki; Lee, Sung-Man

    A carbon-coated Ni 20Si 80 alloy-graphite composite has been studied as the anode for lithium-ion batteries. The composite is prepared by simple heat-treatment of a mixture of coal tar pitch and a Ni 20Si 80-graphite composite at 900 °C and under argon. The Ni 20Si 80 alloy powders are synthesized by mechanical alloying. The composite demonstrates promising electrochemical properties such as high reversible capacity, excellent cycle performance, and sufficiently high initial charge-discharge coulombic efficiency. This suggests buffering and conductive actions on the main active material, viz., Ni 20Si 80 alloy, of the graphite. These two effects are strongly enhanced by the carbon coating treatment.

  17. The effect of the solute on the structure, selected mechanical properties, and biocompatibility of Ti–Zr system alloys for dental applications

    Energy Technology Data Exchange (ETDEWEB)

    Correa, D.R.N.; Vicente, F.B. [UNESP — Univ. Estadual Paulista, Laboratório de Anelasticidade e Biomateriais, 17.033-360, Bauru, SP (Brazil); Donato, T.A.G.; Arana-Chavez, V.E. [USP — Universidade de São Paulo, Faculdade de Odontologia, Departamento de Biologia Oral e Biomateriais, 05.508-900, São Paulo, SP (Brazil); Buzalaf, M.A.R. [USP — Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Ciências Biológicas, 17.012-901, Bauru, SP (Brazil); Grandini, C.R., E-mail: betog@fc.unesp.br [UNESP — Univ. Estadual Paulista, Laboratório de Anelasticidade e Biomateriais, 17.033-360, Bauru, SP (Brazil)

    2014-01-01

    New titanium alloys have been developed with the aim of utilizing materials with better properties for application as biomaterials, and Ti–Zr system alloys are among the more promising of these. In this paper, the influence of zirconium concentrations on the structure, microstructure, and selected mechanical properties of Ti–Zr alloys is analyzed. After melting and swaging, the samples were characterized through chemical analysis, density measurements, X-ray diffraction, optical microscopy, Vickers microhardness, and elasticity modulus. In-vitro cytotoxicity tests were performed on cultured osteogenic cells. The results showed the formation essentially of the α′ phase (with hcp structure) and microhardness values greater than cp-Ti. The elasticity modulus of the alloys was sensitive to the zirconium concentrations while remaining within the range of values of conventional titanium alloys. The alloys presented no cytotoxic effects on osteoblastic cells in the studied conditions. - Highlights: • Ti–Zr alloys for biomedical applications were developed. • Only α′ phase was observed. • Influence of zirconium concentrations on the properties of Ti–Zr alloys was analyzed. • No cytotoxic effects were observed.

  18. The effect of the solute on the structure, selected mechanical properties, and biocompatibility of Ti–Zr system alloys for dental applications

    International Nuclear Information System (INIS)

    New titanium alloys have been developed with the aim of utilizing materials with better properties for application as biomaterials, and Ti–Zr system alloys are among the more promising of these. In this paper, the influence of zirconium concentrations on the structure, microstructure, and selected mechanical properties of Ti–Zr alloys is analyzed. After melting and swaging, the samples were characterized through chemical analysis, density measurements, X-ray diffraction, optical microscopy, Vickers microhardness, and elasticity modulus. In-vitro cytotoxicity tests were performed on cultured osteogenic cells. The results showed the formation essentially of the α′ phase (with hcp structure) and microhardness values greater than cp-Ti. The elasticity modulus of the alloys was sensitive to the zirconium concentrations while remaining within the range of values of conventional titanium alloys. The alloys presented no cytotoxic effects on osteoblastic cells in the studied conditions. - Highlights: • Ti–Zr alloys for biomedical applications were developed. • Only α′ phase was observed. • Influence of zirconium concentrations on the properties of Ti–Zr alloys was analyzed. • No cytotoxic effects were observed

  19. Material challenges for the next generation of fission reactor systems

    International Nuclear Information System (INIS)

    The new generation of fission reactor systems wil require the deployment and construction of a series of advanced water cooled reactors as part of a package of measures to meet UK and European energy needs and to provide a near term non-fossil fuel power solution that addresses CO2 emission limits. In addition new longer term Generation IV reactor tye systems are being developed and evaluated to enhance safety, reliability, sustainability economics and proliferation resistance requirements and to meet alternative energy applications (outside of electricity generation) such as process heat and large scale hydrogen generation. New fission systems will impose significant challenges on materials supply and development. In the near term, because of the need to 'gear up' to large scale construction after decades of industrial hibernation/contraction and, in the longer term, because of the need for materials to operate under more challenging environments requiring the deployment and development of new alternative materials not yet established to an industrial stage. This paper investigates the materials challenges imposed by the new Generation III+ and Generation IV systems. These include supply and fabrication issues, development of new high temperature alloys and non-metallic materials, the use of new methods of manufacture and the best use of currently available resources and minerals. Recommendations are made as to how these materials challenges might be met and how governments, industry, manufacturers and researchers can all play their part. (orig.)

  20. Material challenges for the next generation of fission reactor systems

    Energy Technology Data Exchange (ETDEWEB)

    Buckthorpe, Derek [AMEC, Knutsford, Cheshire (United Kingdom)

    2010-07-01

    The new generation of fission reactor systems wil require the deployment and construction of a series of advanced water cooled reactors as part of a package of measures to meet UK and European energy needs and to provide a near term non-fossil fuel power solution that addresses CO{sub 2} emission limits. In addition new longer term Generation IV reactor tye systems are being developed and evaluated to enhance safety, reliability, sustainability economics and proliferation resistance requirements and to meet alternative energy applications (outside of electricity generation) such as process heat and large scale hydrogen generation. New fission systems will impose significant challenges on materials supply and development. In the near term, because of the need to 'gear up' to large scale construction after decades of industrial hibernation/contraction and, in the longer term, because of the need for materials to operate under more challenging environments requiring the deployment and development of new alternative materials not yet established to an industrial stage. This paper investigates the materials challenges imposed by the new Generation III+ and Generation IV systems. These include supply and fabrication issues, development of new high temperature alloys and non-metallic materials, the use of new methods of manufacture and the best use of currently available resources and minerals. Recommendations are made as to how these materials challenges might be met and how governments, industry, manufacturers and researchers can all play their part. (orig.)

  1. Modelling of residual stresses in valves Norem hard-facing alloys: a material characterization issue

    International Nuclear Information System (INIS)

    Replacement of cobalt-based hard-facing alloys (Stellite) is of high interest within the topic of reduction of human radiation exposure during field-work. Iron-based hard-facing alloys, such as Norem, are considered as good replacement candidates. Their wear characteristics are known to be quite equivalent to Stellite but are counter-balanced by lack of feedback in the field, especially about their resistance/toughness to brutal thermal shocks (60 C - 280 C for primary water). Norem alloys show a solid-solution strengthened austenitic dendrites matrix with a continuous network of eutectic and non-eutectic carbides at the grain boundaries. Toughness evaluation also requires information about residual stresses due to the welding (deposition) process: this work aims at furnishing tools for this purpose. First part of the work involved a microstructural study in order to compare the as-received material to other Norem samples previously observed in EDF's works and literature. A characterization of the different phase evolutions after heating and fast cooling of Norem is then made, in order to characterize whether metallurgical aspects have to be considered in the mechanical part during welding modelling: it appears that no strong solid-solid phase transformation may occur in welding situation. Tensile characterization is then performed on bulk PTAW (Plasma Transferred Arc Welding) specimens. A simplified welding simulation is eventually conducted on different axis-symmetric geometry and on real valve geometry in order to define a representative sample that will be used for further investigation on residual stresses. (authors)

  2. Material flow and microstructural evolution during friction stir spot welding of AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, W. [Center for Friction Stir Processing, Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Mishra, R.S., E-mail: rajiv.mishra@unt.edu [Center for Friction Stir Processing, Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Carlson, B.; Verma, R.; Mishra, R.K. [General Motors R and D Center, Warren, MI 48090 (United States)

    2012-05-01

    Material flow and local texture evolution during friction stir spot welding (FSSW) of AZ31 magnesium alloy was characterized by varying tool rotation rates. Texture at various locations of the welded region was measured using electron backscatter diffraction (EBSD). Material flow is significantly influenced by tool rotation rate with a conical step spiral pin tool, and FSSW introduces a unique basal fiber texture in the welded region. Results indicate that local texture evolution is dominated by shear deformation through material flow. The tool shoulder applies both shear and compressive deformation to the upper region material; however, the rotating pin introduces only shear deformation to the adjacent material. As the tool rotation rate increases, the effect of both tool shoulder and pin becomes more prominent by introducing a higher degree of basal pole tilt with respect to the initial rolling texture at the periphery of the pin, but less tilt in the upper region beneath the tool shoulder undersurface. The equiaxed fine grain structure in the stir zone appears to result from the twinning-induced dynamic recrystallization and discontinuous dynamic recrystallization.

  3. Thermodynamic potential of electrons and phonons system of disordered alloy

    CERN Document Server

    Repetskij, S P

    2002-01-01

    The cluster decomposition for the delayed two-time Green functions and the disordered crystal dynamic potential is obtained with an account of the electron-phonon and electron-electron interactions. The system electron states are described within the frames of the multizone strong coupling model. The calculations are based on the diagram technique for the Green temperature functions. The coherent potential approximation is chosen as the zero mononode approximation in this cluster decomposition method. It is shown that the processes of the contributions of the elementary excitations scattering on the clusters decrease with the cluster nodes number growth in the cluster in correspondence with certain small parameters. The analytical evaluations of the electron-phonon interaction impact on the electron energy spectrum of the ordering alloy are made in the monozone model. The possibility of applying the obtained results for describing the strong electron correlations impact on the electron structure and propertie...

  4. Compatibility of refractory materials for nuclear reactor poison control systems

    Science.gov (United States)

    Sinclair, J. H.

    1974-01-01

    Metal-clad poison rods have been considered for the control system of an advanced space power reactor concept studied at the NASA Lewis Research Center. Such control rods may be required to operate at temperatures of about 140O C. Selected poison materials (including boron carbide and the diborides of zirconium, hafnium, and tantalum) were subjected to 1000-hour screening tests in contact with candidate refractory metal cladding materials (including tungsten and alloys of tantalum, niobium, and molybdenum) to assess the compatibility of these materials combinations at the temperatures of interest. Zirconium and hafnium diborides were compatible with refractory metals at 1400 C, but boron carbide and tantalum diboride reacted with the refractory metals at this temperature. Zirconium diboride also showed promise as a reaction barrier between boron carbide and tungsten.

  5. Material control system simulator user's manual

    International Nuclear Information System (INIS)

    This report describes the use of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts

  6. Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development program. Progress report, October 1, 1981-December 31, 1981. [Alloy-MA-956; alloy-MA-754

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, O.F.

    1982-06-15

    Work covered in this report includes the activities associated with the status of the simulated reactor helium supply systems and testing equipment. The progress in the screening test program is descibed; this includes: screening creep results and metallographic analysis for materials thermally exposed or tested at 750/sup 0/, 850/sup 0/, 950/sup 0/ and 1050/sup 0/C (1382/sup 0/, 1562/sup 0/, 1742/sup 0/, and 1922/sup 0/F) in controlled-purity helium. The status of creep-rupture in controlled-purity helium and air and fatigue testing in the controlled-purity helium in the intensive screening test program is discussed. The results of metallographic studies of screening alloys exposed in controlled-purity helium for 3000 hours at 750/sup 0/C and 5500 hours at 950/sup 0/C, 3000 hours at 1050/sup 0/C and 6000 hours at 1050/sup 0/C and for weldments exposed in controlled-purity helium for 6000 hours at 750/sup 0/C and 6000 hours at 1050/sup 0/C are presented and discussed.

  7. Sulfidation, down time corrosion and corrosion assisted cracking on high alloyed materials in synthetic coal gasifier environments

    Energy Technology Data Exchange (ETDEWEB)

    Huijbregts, W.M.M.; Kokmeijer, E.; Van Zuilen, H.G. (KEMA Inspecties en Materialen, Arnhem (Netherlands))

    1993-01-01

    The research on the title subject is aimed at finding suitable materials for heat exchangers in coal gasification installations. Some materials are tested regarding their sensitivity for the title corrosion types under coal gasification conditions. The tested materials are AISI 310, Sanicro 28, AC66, Alloy 800, chromium diffusion coatings and Inconel 625. To investigate and qualify the corrosion layers use is made of light and electron microscopy techniques

  8. Materials for spaceborne laser systems

    International Nuclear Information System (INIS)

    Advanced laser systems are attracting a growing interest for space missions, in particular for LIDAR (LIght Detection And Ranging) applications. An important issue for the LIDARs is the very strict requirements on the optical performance and more specifically the need for a high optical output power combined with a nearly perfect output beam quality. These features are traditionally in conflict with each other. Thermally induced phase distortions indeed corrupt the beam quality of high-power solid-state lasers and it becomes increasingly difficult to maintain a good beam quality while increasing the output power. A possible solution of the problem is to use the optical phase conjugation, which provides a method to dynamically correct for those aberrations. A process by which phase-conjugated waves can be generated is the SBS (stimulated Brillouin scattering). SBS mirrors commonly used in terrestrial application are based on liquids or gases, which are not 'space-friendly' and often toxic. The solid-state alternative seems the most appropriate for space. Such PCMs (Phase-Conjugating Mirrors) have been the subject of many research efforts in recent years and a significant progress in improving their characteristics has been achieved. However, the issue of space qualification remains open. To address it, the European Space Agency initiated in 2004 the research project named Solid-State Phase Conjugation, Radiation Testing and Evaluation for Core Laser Technologies with the TRT (Thales Research and Technology), France, as the prime contractor, and the CSL (Centre Spatial de Liege) and SCKCEN as the subcontractors. The project is to be completed in 2006. To qualify a PCM for a spaceborne laser system, one has to address a number of specific issues. Such a component must be mechanically rugged to sustain vibrations during the launch phase, provide a low out-gassing to prevent optical surfaces contamination in vacuum, be highly reliable to operate properly without

  9. Influence of cooling rates on properties of pre-alloyed PM materials

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-11-01

    Full Text Available Purpose: The paper focuses on microstructural and mechanical properties of pre-alloyed Astaloy CrL and CrM sintered steels with high addition of carbon.Design/methodology/approach: The main objective of the present work was to establish the effect of cooling rates on the microstructure and properties such as: Charpy impact test, microhardness, wear resistance (disk on disk test were evaluated depending on chemical composition. Compacts containing low amounts of chromium, molybdenum and high amount of graphite were sintered in a vacuum furnace at 1120ºC in vacuum atmosphere and rapidly cooled in nitrogen with two different rates. Then compacts were tempered in vacuum, and cooled in nitrogen. Obtained samples were analysed by light optical microscopy (LOM for microstructure observation and scanning electron microscopy (SEM with EDS for chemical composition.Findings: Sinter hardening is a cost-effective process that consists of sintering and heat treatment in one step, so it minimizes the number of processing steps. It is known that the cooling rate following sintering greatly affect material microstructure, which determine the final properties of sinter-hardened materials. The objective was to understand how sintering conditions influence the development of microstructures and thereby control mechanical properties of materials.Practical implications: Changing the amount of graphite element and cooling rates, will affect the amount of ferrite, perlite, martensite and bainite in the microstructure. Further tests should be carried out in order to examine different cooling rates.Originality/value: Sinter-hardening of CrL and CrM pre-alloyed powders with addition of graphite was investigated to study cooling mechanism.

  10. Generator cooling hydrogen purity improvement system using hydrogen absorbing alloy; Suiso kyuzo gokin riyo hatsudenkinai suiso jundo kojo system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, H.; Kabutomori, T.; Wakisaka, Y. [Japan Steel Works, Ltd., Tokyo (Japan); Nishimura, Y.; Kogi, T.; Sato, J.; Haruki, N. [Kansai Electric Power Co. Inc., Osaka (Japan); Fujita, T. [Mitsubishi Electric Corp., Tokyo (Japan)

    1998-09-15

    Described herein is a system which uses a hydrogen-absorbing alloy to purify a hydrogen gas stream used as a coolant for power generator. Hydrogen in the stream containing impurities such as nitrogen can be selectively absorbed by sufficiently cooled hydrogen-absorbing alloy. Impurity gases concentrated in the alloy pores are released, and then the alloy is heated to release hydrogen. This purifies hydrogen to at least 99.99%. This system essentially consists of an hydrogen-absorbing unit, hot water production/supply system which circulates hot water of 80 to 90degC to release hydrogen out of the alloy, pretreatment unit, and temperature and pressure sensors. It is confirmed, by the test in which the system is connected to a commercial power generator of 600MW, that the system can be continuously operated to purify hydrogen to at least 99.9% for an extended period. 4 refs., 18 figs., 1 tab.

  11. Material modelling for creep-age forming of aluminium alloy 7B04

    Directory of Open Access Journals (Sweden)

    Lam Aaron C.L.

    2015-01-01

    Full Text Available This paper presents a study on the creep-ageing behaviour of a peak-aged aluminium alloy 7B04 under different tensile loads at 115oC and subsequently modelling it for creep-age forming (CAF applications. Mechanical properties and microstructural evolutions of creep-aged specimens were investigated. The material was modelled using a set of unified constitutive equations, which not only captures the material's creep deformation but also takes into account yield strength contributions from solid solution hardening, age hardening and dislocation hardening during creep-ageing. A possible application of the present work is demonstrated by implementing the determined material model into a commercial finite element analysis solver via a user-defined subroutine for springback prediction of creep-age formed plates. A good agreement is observed between the simulated springback values and experimental results. This material model now enables further investigations of 7B04 under various CAF scenarios to be conducted inexpensively via computational modelling.

  12. Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System

    International Nuclear Information System (INIS)

    Microbiologically influenced corrosion (MIC) may decrease the functional lifetime of nuclear waste packaging materials in the potential geologic repository at Yucca Mountain (YM), Nevada. Biochemical contributions to corrosion of package materials are being determined in reactors containing crushed repository-site rock with the endogenous microbial community, and candidate waste package materials. These systems are being continually supplied with simulated ground water. Periodically, bulk chemistries are analyzed on the system outflow, and surfacial chemistries are assessed on withdrawn material coupons. Both Fe and Mn dissolved from C1020 coupons under conditions that included the presence of YM microorganisms. Insoluble corrosion products remained in a reduced state at the coupon surface, indicating at least a localized anoxic condition; soluble reduced Mn and Fe were also detected in solution, while precipitated and spalled products were oxidized. Alloy 22 surfaces showed a layer of chrome oxide, almost certainly in the Cr(III) oxidation state, on microcosm-exposed coupons, while no soluble chrome was detected in solution. The results of these studies will be compared to identical testing on systems containing sterilized rock to generate, and ultimately predict, microbial contributions to waste package corrosion chemistries

  13. Investigation of austenitic alloys for advanced heat recovery and hot gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.; Ren, W. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    Alloys for design and construction of structural components needed to contain process streams and provide internal structures in advanced heat recovery and hot gas cleanup systems were examined. Emphasis was placed on high-strength, corrosion-resistant alloys for service at temperatures above 1000 {degrees}F (540{degrees}C). Data were collected that related to fabrication, joining, corrosion protection, and failure criteria. Alloys systems include modified type 310 and 20Cr-25Ni-Nb steels and sulfidation-resistance alloys HR120 and HR160. Types of testing include creep, stress-rupture, creep crack growth, fatigue, and post-exposure short-time tensile. Because of the interest in relatively inexpensive alloys for high temperature service, a modified type 310 stainless steel was developed with a target strength of twice that for standard type 310 stainless steel.

  14. Designing Biomimetic, Dissipative Material Systems

    Energy Technology Data Exchange (ETDEWEB)

    Balazs, Anna C. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Whitesides, George M. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology; Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering. Dept. of Chemistry. Dept. of Molecular Genetics and Microbiology. Center for Micro-Engineered Materials; Aranson, Igor S. [UChicago, LLC., Argonne, IL (United States); Chaikin, Paul [New York Univ. (NYU), NY (United States). Dept. of Physics; Dogic, Zvonimir [Brandeis Univ., Waltham, MA (United States). Dept. of Physics; Glotzer, Sharon [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering. Dept. of Materials Science and Engineering. Dept. of Macromolecular Science and Engineering Physics; Hammer, Daniel [Univ. of Pennsylvania, Philadelphia, PA (United States). School of Engineering and Applied Science; Irvine, Darrell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering and Biological Engineering; Little, Steven R. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Olvera de la Cruz, Monica [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Parikh, Atul N. [Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering. Dept. of Chemical Engineering and Materials Science; Stupp, Samuel [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering. Dept. of Chemistry. Dept. of Medicine. Dept. of Biomedical Engineering; Szostak, Jack [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology

    2016-01-21

    Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.

  15. Characterization of excel alloy pressure tube material for CANDU SCW reactors

    International Nuclear Information System (INIS)

    The phase transformation temperatures, aging response, and creep rupture strength of Zr alloy Excel (Zr- 3.5%Sn- 0.8%Nb- 0.8%Mo) pressure tube material were investigated. The α → α+β and α+β → β transus temperatures were found to be in the range of 600-690 °C and 962-975 °C respectively. Precipitation hardening was observed in the microstructures water-quenched from high in the α+β or β regions followed by aging at 400-500 °C for 1 hr. The results of creep-rupture experiments at 400 °C suggest that a fully martensitic and aged microstructure has better creep properties at high stress levels (>700 MPa) and a microstructure obtained by air-cooling from high in the α+β region shows good creep properties at lower stresses (<560 MPa). (author)

  16. Biologically-Induced Micropitting of Alloy 22, a Candidate Nuclear Waste Packaging Material

    International Nuclear Information System (INIS)

    The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment (or microcosm) consisting of crushed rock (tuff) from the Yucca Mountain repository site and a continual flow of simulated groundwater for periods up to five years at room temperature and 30 C. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis by scanning electron microscopy of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Room temperature, biotically-incubated coupons show a wide distribution of pores covering the coupon surface, while coupons incubated at 30 C show the pores restricted to polishing ridges

  17. Composition of sputtered material from CuNi alloy during Xe + ion sputtering at elevated temperatures

    Science.gov (United States)

    Sekine, Shigeyuki; Shimizu, Hazime; Ichimura, Singo

    1995-04-01

    Polycrystalline CuNi alloys were sputtered by 3 kV Xe + ions at elevated temperatures to analyze the ion-beam-induced diffusion. The time evolution of the composition of the sputtered materials from the start of the sputtering was measured by TOF-SNMS (time-of-flight sputtered neutral mass spectrometry). During removal of the Gibbsian segregation layer of copper, the sputtered flux consisted of almost only copper atoms. Then, the copper content gradually decreased due to the formation of a sputter-induced copper-depleted surface layer, and reached an almost steady state with still higher copper content than the bulk composition. From the temperature dependence of the composition at the quasi-steady state the activation energy of copper transportation through a high diffusivity path was derived to be 54 kJ mol -1 (0.56 eV). The high diffusivity path was assigned to copper diffusion through grain boundaries.

  18. Corrosion of alloys of the niobium--titanium--aluminium system

    International Nuclear Information System (INIS)

    The mechanical properties and corrosion resistance of niobium--titanium--aluminum alloys in 20 percent HCl and 40--75 percent H2SO4 at 40 and 1000C are considered. Current density vs potential and corrosion rate vs potential potentiostatic curves plotted in 75 percent H2SO4 at 1400C for the alloys with different titanium contents at a constant content of aluminum and also for alloys with a constant titanium content at different contents of aluminum are given. It was shown that the corrosion resistance of the alloys in 75 percent H2SO4 at 1400C is an exponential function of the atomic content of the alloying components (Ti, Al) in them; aluminum vitiates the corrosion resistance very strongly

  19. Research on arc erosion of silver-based alloy contact materials under low voltage, resistive load and small current at 400 Hz and 50 Hz

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Zhi-ying Ma

    2009-01-01

    By using a self-developed IF power and a ASTM contact material experimental system of small-capacity and variable frequency, the value of arcing characteristics and the welding force of the silver-based contact material are acquired under low voltage, resistive load and small current at 400 Hz and 50 Hz. By means of an electricity-ray analytical balance, SEM and EDAX, the weighing values of the contact materials and the changes of AgCdO, AgNi, AgC and AgW contact material surface profile and micro-area constituent are obtained and analyzed. The arc erosion causes of silver-based alloy contact materials at 400 Hz and 50 Hz are also discussed.

  20. Solid State Joining of High Temperature Alloy Tubes for USC and Heat-Exchanger Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bimal Kad

    2011-12-31

    The principal objective of this project was to develop materials enabling joining technologies for use in forward looking heat-exchanger fabrication in Brayton cycle HIPPS, IGCC, FutureGen concepts capable of operating at temperatures in excess of 1000{degree}C as well as conventional technology upgrades via Ultra Super-Critical (USC) Rankine-cycle boilers capable of operating at 760{degree}C (1400F)/38.5MPa (5500psi) steam, while still using coal as the principal fossil fuel. The underlying mission in Rankine, Brayton or Brayton-Rankine, or IGCC combined cycle heat engine is a steady quest to improving operating efficiency while mitigating global environmental concerns. There has been a progressive move to higher overall cycle efficiencies, and in the case of fossil fuels this has accelerated recently in part because of concerns about greenhouse gas emissions, notably CO{sub 2}. For a heat engine, the overall efficiency is closely related to the difference between the highest temperature in the cycle and the lowest temperature. In most cases, efficiency gains are prompted by an increase in the high temperature, and this in turn has led to increasing demands on the materials of construction used in the high temperature end of the systems. Our migration to new advanced Ni-base and Oxide Dispersion Strengthened (ODS) alloys poses significant fabrication challenges, as these materials are not readily weldable or the weld performs poorly in the high temperature creep regime. Thus the joining challenge is two-fold to a) devise appropriate joining methodologies for similar/dissimilar Ni-base and ODS alloys while b) preserving the near baseline creep performance in the welded region. Our program focus is on solid state joining of similar and dissimilar metals/alloys for heat exchanger components currently under consideration for the USC, HIPPS and IGCC power systems. The emphasis is to manipulate the joining methods and variables available to optimize joint creep

  1. Mechanisms Governing the Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Vijay [Univ. of Cincinnati, OH (United States); Carroll, Laura [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sham, Sam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-06

    This research project, which includes collaborators from INL and ORNL, focuses on the study of alloy 617 and alloy 800H that are candidates for applications as intermediate heat exchangers in GEN IV nuclear reactors, with an emphasis on the effects of grain size, grain boundaries and second phases on the creep properties; the mechanisms of dislocation creep, diffusional creep and cavitation; the onset of tertiary creep; and theoretical modeling for long-term predictions of materials behavior and for high temperature alloy design.

  2. Effect of materials and temperature on the forward extrusion of magnesium alloys

    International Nuclear Information System (INIS)

    Magnesium alloys are being extensively used in weight-saving applications and as a potential replacement for plastics in electronic and computer applications. However, processing of magnesium has always been a challenge for manufacturing industries owing to their high brittleness despite their good EMI shielding property and high specific strength. Despite these advantages, they are limited by their processability. The present work aims to evaluate lower temperature formability of magnesium alloys. Three different materials were selected for axisymmetric extrusion tests, namely AZ31, AZ61 and the forging alloy, ZK 60. To establish the size and capacity of the press required to perform these forming trials and to know the formability, simulation using finite element analysis was carried on a representative material AZ31 using the properties established based on earlier work. A die set with a die shoe was designed to perform the forward extrusion trials. The area reduction ratio for forward extrusion was fixed at 41% for the die design and simulation. The maximum strain is given as ln(Ao/Af) ∼ 0.88 in the case of forward extrusion. The temperature was varied with a temperature controller built in-house from room temperature (RT) to 300 deg.C. However, the results provided below only include the tests carried out at RT, 100, 150, 175 and 200 deg.C. Although the forming trials were successful above 200 deg.C, there was difficulty in removing the specimens from the die cavity. Secondly, the process of removing the samples in the case of AZ31 and ZK 60 resulted in cracking, so it was difficult to evaluate the samples and the process. However, AZ61 samples did not show any evidence of crack formation during ejection of the formed sample. Simulation results and experimental trials showed that magnesium (AZ31) could be easily formed at elevated temperatures of 300 deg.C. Though there was a good correlation on the yield point prediction between simulation and experimental

  3. Incorporation of Integral Fuel Burnable Absorbers Boron and Gadolinium into Zirconium-Alloy Fuel Clad Material

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, K.; Renk, T.J.; Lahoda, E.J.; Corradini, M.L

    2004-12-14

    Long-lived fuels require the use of higher enrichments of 235U or other fissile materials. Such high levels of fissile material lead to excessive fuel activity at the beginning of life. To counteract this excessive activity, integral fuel burnable absorbers (IFBA) are added to some rods in the fuel assembly. The two commonly used IFBA elements are gadolinium, which is added as gadolinium-oxide to the UO2 powder, and boron, which is applied as a zirconium-diboride coating on the UO2 pellets using plasma spraying or chemical vapor deposition techniques. The incorporation of IFBA into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be very costly because of their small volume and can add from 20 to 30% to the manufacturing cost of the fuel. Other manufacturing issues that impact cost and performance are maintaining the correct levels of dosing, the reduction in fuel melting point due to gadolinium-oxide additions, and parasitic neutron absorption at fuel's end-of-life. The goal of the proposed research is to develop an alternative approach that involves incorporation of boron or gadolinium into the outer surface of the fuel cladding material rather than as an additive to the fuel pellets. This paradigm shift will allow for the introduction of the IFBA in a non-nuclear regulated environment and will obviate the necessity of additional handling and processing of the fuel pellets. This could represent significant cost savings and potentially lead to greater reproducibility and control of the burnable fuel in the early stages of the reactor operation. The surface alloying is being performed using the IBEST (Ion Beam Surface Treatment) process developed at Sandia National Laboratories. IBEST involves the delivery of energetic ion beam pulses onto the surface of a material, near-surface melting, and rapid solidification. The non-equilibrium nature of such processing allows for

  4. Materials Selection for Aerospace Systems

    Science.gov (United States)

    Arnold, Steven M.; Cebon, David; Ashby, Mike

    2012-01-01

    A systematic design-oriented, five-step approach to material selection is described: 1) establishing design requirements, 2) material screening, 3) ranking, 4) researching specific candidates and 5) applying specific cultural constraints to the selection process. At the core of this approach is the definition performance indices (i.e., particular combinations of material properties that embody the performance of a given component) in conjunction with material property charts. These material selection charts, which plot one property against another, are introduced and shown to provide a powerful graphical environment wherein one can apply and analyze quantitative selection criteria, such as those captured in performance indices, and make trade-offs between conflicting objectives. Finding a material with a high value of these indices maximizes the performance of the component. Two specific examples pertaining to aerospace (engine blades and pressure vessels) are examined, both at room temperature and elevated temperature (where time-dependent effects are important) to demonstrate the methodology. The discussion then turns to engineered/hybrid materials and how these can be effectively tailored to fill in holes in the material property space, so as to enable innovation and increases in performance as compared to monolithic materials. Finally, a brief discussion is presented on managing the data needed for materials selection, including collection, analysis, deployment, and maintenance issues.

  5. Nickel and its alloys as perspective materials for intermediate temperature steam electrolysers operating on proton conducting solid acids as electrolyte

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Jensen, Jens Oluf;

    2012-01-01

    Several stainless steels, nickel-based alloys, Ta-coated stainless steel, niobium, nickel, platinum and gold were evaluated as possible materials for use in the intermediate temperature water electrolysers. The corrosion resistance was measured in molten KH2PO4 as simulated conditions corresponding...

  6. Shape memory alloys applied to improve rotor-bearing system dynamics - an experimental investigation

    DEFF Research Database (Denmark)

    Enemark, Søren; Santos, Ilmar; Savi, Marcelo A.

    2015-01-01

    passing through critical speeds. In this work, the feasibility of applying shape memory alloys to a rotating system is experimentally investigated. Shape memory alloys can change their stiffness with temperature variations and thus they may change system dynamics. Shape memory alloys also exhibit......tor-bearing systems have critical speeds and to pass through them is an ongoing challenge in the field of mechanical engineering. The incorporation of shape memory alloys in rotating systems has an increasing importance to improve system performance and to avoid potential damaging situations when...... hysteretic stress-strain relations which may be utilized for damping purposes. These ideas are tested in this study on a dedicated test-rig, consisting of a rigid shaft and disc held vertically by passive magnetic bearings, where the damping is low. The bearing housings is flexibly supported by shape memory...

  7. Inline evenflow material distributor for pneumatic material feed systems

    Science.gov (United States)

    Thiry, Michael J.

    2007-02-20

    An apparatus for reducing clogs in a pneumatic material feed line, such as employed in abrasive waterjet machining systems, by providing an evenflow feed of material therethrough. The apparatus preferably includes a hollow housing defining a housing volume and having an inlet capable of connecting to an upstream portion of the pneumatic material feed line, an outlet capable of connecting to a downstream portion of the pneumatic material feed line, and an air vent located between the inlet and outlet for venting excess air pressure out from the housing volume. A diverter, i.e. an impingement object, is located at the inlet and in a path of incoming material from the upstream portion of the pneumatic material feed line, to break up clumps of ambient moisture-ridden material impinging on the diverter. And one or more filter screens is also preferably located in the housing volume to further break up clumps and provide filtering.

  8. Perspectives of molibdenum containing materials application for alloying of iron-carbon alloys during manufacturing of critical castings

    OpenAIRE

    A. G. Slutsky; A. S. Kalinichenko; R. E. Trubitsky; V. A. Sheinert

    2015-01-01

    Motor is one of most important part of automobile determine its economical effectiveness of usage. On the other hand, sleeves, pistons and rings are crucible parts as they determine the service life of a motor. These parts are producing in big scale – dozens of millions pieces. Increase of cylinder sleeves physical-mechanical properties results in prolongation of motor service life and improvement of motor’s characteristics. Nowadays low alloyed cast irons with perlite structure are used to m...

  9. Comparative study on structure, corrosion and hardness of Zn-Ni alloy deposition on AISI 347 steel aircraft material

    Energy Technology Data Exchange (ETDEWEB)

    Gnanamuthu, RM. [Department of Chemical Engineering, College of Engineering, Kyung Hee University, 1732 Deogyeong-daero, Gihung, Yongin, Gyeonggi 446-701 (Korea, Republic of); Mohan, S., E-mail: sanjnamohan@yahoo.com [Central Electrochemical Research Institute, (CSIR), Karaikudi 630 006, Tamilnadu (India); Saravanan, G. [Central Electrochemical Research Institute, (CSIR), Karaikudi 630 006, Tamilnadu (India); Lee, Chang Woo, E-mail: cwlee@khu.ac.kr [Department of Chemical Engineering, College of Engineering, Kyung Hee University, 1732 Deogyeong-daero, Gihung, Yongin, Gyeonggi 446-701 (Korea, Republic of)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Electrodeposition of Zn-Ni alloy on AISI 347 steel as an aircraft material has been carried out from various baths. Black-Right-Pointing-Pointer The effect of pulse duty cycle on thickness, current efficiency and hardness reached maximum values at 40% duty cycle and for 50 Hz frequencies average current density of 4 A dm{sup -2}. Black-Right-Pointing-Pointer The XRF characterizations of 88:12% Zn-Ni alloy provided excellent corrosion resistance. Black-Right-Pointing-Pointer It is found that Zn-Ni alloy on AISI 347 aircraft material has better structure and corrosion resistance by pulse electrodeposits from electrolyte-4. - Abstract: Zn-Ni alloys were electrodeposited on AISI 347 steel aircraft materials from various electrolytes under direct current (DCD) and pulsed electrodepositing (PED) techniques. The effects of pulse duty cycle on thickness, current efficiency and hardness of electrodeposits were studied. Alloy phases of the Zn-Ni were indexed by X-ray diffraction (XRD) techniques. Microstructural morphology, topography and elemental compositions were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray fluorescence spectroscopy (XRF). The corrosion resistance properties of electrodeposited Zn-Ni alloy in 3.5% NaCl aqueous solution obtained by DCD and PED were compared using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) technique. Elemental analysis showed that 88% of Zn and 12% of Ni obtained from electrolyte-4 by PED technique at 40% duty cycle for 50 Hz frequencies having better corrosion resistance than that of deposits obtained from other electrolytes.

  10. Mechanistic Studies Of Combustion And Structure Formation During Combustion Synthesis Of Advanced Materials: Phase Separation Mechanism For Bio-Alloys

    Science.gov (United States)

    Varma, A.; Lau, C.; Mukasyan, A.

    2003-01-01

    Among all implant materials, Co-Cr-Mo alloys demonstrate perhaps the most useful balance of resistance to corrosion, fatigue and wear, along with strength and biocompatibility [1]. Currently, these widely used alloys are produced by conventional furnace technology. Owing to high melting points of the main alloy elements (e.g. Tm.p.(Co) 1768 K), high-temperature furnaces and long process times (several hours) are required. Therefore, attempts to develop more efficient and flexible methods for production of such alloys with superior properties are of great interest. The synthesis of materials using combustion phenomena is an advanced approach in powder metallurgy [2]. The process is characterized by unique conditions involving extremely fast heating rates (up to 10(exp 6 K/s), high temperatures (up to 3500 K), and short reaction times (on the order of seconds). As a result, combustion synthesis (CS) offers several attractive advantages over conventional metallurgical processing and alloy development technologies. The foremost is that solely the heat of chemical reaction (instead of an external source) supplies the energy for the synthesis. Also, simple equipment, rather than energy-intensive high-temperature furnaces, is sufficient. This work was devoted to experiments on CS of Co-based alloys by utilizing thermite (metal oxide-reducing metal) reactions, where phase separation subsequently produces materials with tailored compositions and properties. Owing to high reaction exothermicity, the CS process results in a significant increase of temperature (up to 3000 C), which is higher than melting points of all products. Since the products differ in density, phase separation may be a gravitydriven process: the heavy (metallic phase) settles while the light (slag) phase floats. The goal was to determine if buoyancy is indeed the major mechanism that controls phase segregation.

  11. Modeling and Simulating Material Behavior during Hot Blank - Cold Die (HB-CD) Stamping of Aluminium Alloy Sheets

    Science.gov (United States)

    Zhang, Nan; Abu-Farha, Fadi

    2016-08-01

    Hot blank - cold die (HB-CD) stamping, non-isothermal hot stamping, of aluminium alloy sheets offers great opportunities for high production rates at low cost, while overcoming limited material formability issues. Yet developing an accurate model that can describe the complex material behavior over the wide ranging conditions of HB-CD stamping (temperatures ranging between 25 and 350 °C) is challenging. Moreover, validation of the developed models under transient conditions is problematic. This work presents he results of a comprehensive characterization, material modeling, FE simulation and experimental validation effort to capture the behavior of an aluminium alloy sheet during HB-CD stamping. In particular, we highlight the integration between temperature measurements (thermography) and strain measurements (digital image correlation) for the accurate validation of model predictions of non-isothermal material deformation.

  12. Reference material systems: a sourcebook for material assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N. (ed.)

    1976-12-01

    A reference set of data related to material systems and a framework for carrying out the material technologies assessment are presented. While the bulk of renewables have been considered in this report, the nonrenewable materials dealt with here include structural materials only, such as steel, aluminum, cement and concrete, and bricks. The complete data set is supposed to include material flows, energy requirements, capital and labor inputs, and environmental effects for each process that a resource must go through to become a useful material for an end use. Although effort has been made to obtain as much information as possible, considerable gaps in data, apparent throughout this report, could not be avoided. A new material technology can be evaluated by substituting that technology for appropriate elements of the reference materials system and calculating the net change in material resource, energy, capital and labor requirements, and environmental impacts. This combination of information thus serves as a means of evaluating the potential benefits to be gained by research in various material technologies.

  13. Nonlinear Analysis of Shape Memory Alloy Component in Rotor System

    Institute of Scientific and Technical Information of China (English)

    王洪礼; 赵涛; 竺致文

    2004-01-01

    The active control of rotor vibration was studied while shape memory alloy (SMA) spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SMA with electric heating method. The SMA spring component has nonlinear coupling problem of thermal stress and thermal elasticity,because thermal constants α,β and elasticity constants λ,G vary with temperature when temperature changes sharply. Because δ,ε were both small parameters, their square items could be ignored and approximate results were obtained by perturbation. The characters of α,β,λ,G changing with temperature were analyzed. Results show that the character of thermal diffusivity α changes with temperature, which cannot influence U,Ψ,So the nonlinearity of α can be ignored; the character of β changes with temperature, which cannot influence U, but influences Ψ at high temperature; the character of λ,G change with temperature, which cannot influence Ψ, but influences U with U(01)ε. The more λ,G, the more their influence on U; the nonlinearity of (βT)/(ρcv)εkk influences U and Ψ, which must be calculated.

  14. Structure and mechanical properties of the three-layer material based on a vanadium alloy and corrosion-resistant steel

    Science.gov (United States)

    Nikulin, S. A.; Rozhnov, A. B.; Nechaikina, T. A.; Rogachev, S. O.; Zavodchikov, S. Yu.; Khatkevich, V. M.

    2014-10-01

    The quality of three-layer pipes has been studied; they are manufactured by hot pressing of a three-layer assembly of tubular billets followed by forging and cold rolling. The operating core is made from a V-4Ti-4Cr alloy. The protective claddings are made from corrosion-resistant steels of two grades, 08Kh17T and 20Kh13. The results of investigation into the structure and microhardness of the junction zone of steel and the vanadium alloy, which includes a contact zone and a transition diffusion layer, are reported. The 08Kh17T steel is shown to be a preferred cladding material.

  15. Particle Based Alloying by Accumulative Roll Bonding in the System Al-Cu

    Directory of Open Access Journals (Sweden)

    Mathias Göken

    2011-11-01

    Full Text Available The formation of alloys by particle reinforcement during accumulative roll bonding (ARB, and subsequent annealing, is introduced on the basis of the binary alloy system Al-Cu, where strength and electrical conductivity are examined in different microstructural states. An ultimate tensile strength (UTS of 430 MPa for Al with 1.4 vol.% Cu was reached after three ARB cycles, which almost equals UTS of the commercially available Al-Cu alloy AA2017A with a similar copper content. Regarding electrical conductivity, the UFG structure had no significant influence. Alloying of aluminum with copper leads to a linear decrease in conductivity of 0.78 µΩ∙cm/at.% following the Nordheim rule. On the copper-rich side, alloying with aluminum leads to a slight strengthening, but drastically reduces conductivity. A linear decrease of electrical conductivity of 1.19 µΩ∙cm/at.% was obtained.

  16. Systems and methods for treating material

    Energy Technology Data Exchange (ETDEWEB)

    Scheele, Randall D; McNamara, Bruce K

    2014-10-21

    Systems for treating material are provided that can include a vessel defining a volume, at least one conduit coupled to the vessel and in fluid communication with the vessel, material within the vessel, and NF.sub.3 material within the conduit. Methods for fluorinating material are provided that can include exposing the material to NF.sub.3 to fluorinate at least a portion of the material. Methods for separating components of material are also provided that can include exposing the material to NF.sub.3 to at least partially fluorinate a portion of the material, and separating at least one fluorinated component of the fluorinated portion from the material. The materials exposed to the NF.sub.3 material can include but are not limited to one or more of U, Ru, Rh, Mo, Tc, Np, Pu, Sb, Ag, Am, Sn, Zr, Cs, Th, and/or Rb.

  17. Titanium alloys in total joint replacement--a materials science perspective.

    Science.gov (United States)

    Long, M; Rack, H J

    1998-09-01

    Increased use of titanium alloys as biomaterials is occurring due to their lower modulus, superior biocompatibility and enhanced corrosion resistance when compared to more conventional stainless steels and cobalt-based alloys. These attractive properties were a driving force for the early introduction of alpha (cpTi) and alpha + beta (Ti-6A1-4V) alloys as well as for the more recent development of new Ti-alloy compositions and orthopaedic metastable beta titanium alloys. The later possess enhanced biocompatibility, reduced elastic modulus, and superior strain-controlled and notch fatigue resistance. However, the poor shear strength and wear resistance of titanium alloys have nevertheless limited their biomedical use. Although the wear resistance of beta-Ti alloys has shown some improvement when compared to alpha + beta alloys, the ultimate utility of orthopaedic titanium alloys as wear components will require a more complete fundamental understanding of the wear mechanisms involved. This review examines current information on the physical and mechanical characteristics of titanium alloys used in artifical joint replacement prostheses, with a special focus on those issues associated with the long-term prosthetic requirements, e.g., fatigue and wear.

  18. Broadband Phonon Scattering in PbTe-based Materials Driven Near the Peierls Phase Transition by Strain or Alloying

    Science.gov (United States)

    Savic, Ivana; Murphy, Ronan; Murray, Eamonn; Fahy, Stephen

    Efficient thermoelectric energy conversion is highly desirable as 60% of the consumed energy is wasted as heat. Low lattice thermal conductivity is one of the key factors leading to high thermoelectric efficiency of a material. However, the major obstacle in the design of such materials is the difficulty in efficiently scattering phonons across the frequency spectrum. Using first principles calculations, we predict that driving PbTe materials close to a Peierls-like phase transition could be a powerful strategy to solve this problem. We illustrate this concept by applying tensile [001] strain to PbTe and its alloys with another rock-salt IV-VI material, PbSe; and by alloying PbTe with a IV-VI Peierls-distorted material, GeTe. This induces extremely soft optical modes, which increase acoustic-optical phonon coupling and decrease phonon lifetimes at all frequencies. We show that PbTe, Pb(Se,Te) and (Pb,Ge)Te alloys driven near the phase transition in the described manner could have the lattice thermal conductivity considerably lower than that of PbTe. The proposed concept may open new opportunities for the development of more efficient thermoelectric materials. This work was supported by Science Foundation Ireland and the Marie-Curie Action COFUND under Starting Investigator Research Grant 11/SIRG/E2113.

  19. Preselection of Ni-Cr(-Mo) alloys as potential canister materials for vitrified high active nuclear waste by electrochemical testing

    Science.gov (United States)

    Bort, H.; Wolf, I.; Leistikow, S.

    1987-07-01

    Several Ni-Cr(-Mo) alloys (Hastelloy C4, Inconel 625, Sanicro 28, Incoloy 825, Inconel 690) were tested by electrochemical methods to characterize their corrosion behavior in chloride containing solutions at various temperatures and pH-values in respect to their application as canister materials for final radioactive waste storage. Especially, Hastelloy C4 was tested by potentiodynamic, potentiostatic and galvanostic measurements. As electrolytes H 2SO 4 solutions were used, as parameters temperature, chloride content and pH-value were varied. All tested alloys showed a clearly limited resistance against pitting corrosion phenomena; under severe conditions even crevice corrosion phenomena were observed. The best corrosion behavior, however, is shown by Hastelloy C4, which has the lowest passivation current density of all tested alloys and the largest potential region with protection against local corrosion phenomena.

  20. Preselection of Ni-Cr(-Mo) alloys as potential canister materials for vitrified high active nuclear waste by electrochemical testing

    Energy Technology Data Exchange (ETDEWEB)

    Bort, H.; Wolf, I.; Leistikow, S.

    1987-07-01

    Several Ni-Cr(-Mo) alloys (Hastelloy C4, Inconel 625, Sanicro 28, Incoloy 825, Inconel 690) were tested by electrochemical methods to characterize their corrosion behavior in chloride containing solutions at various temperatures and pH-values in respect to their application as canister materials for final radioactive waste storage. Especially, Hastelloy C4 was tested by potentiodynamic, potentiostatic and galvanostic measurements. As electrolytes H/sub 2/SO/sub 4/ solutions were used, as parameters temperature, chloride content and pH-value were varied. All tested alloys showed a clearly limited resistance against pitting corrosion phenomena; under severe conditions even crevice corrosion phenomena were observed. The best corrosion behavior, however, is shown by Hastelloy C4, which has the lowest passivation current density of all tested alloys and the largest potential region with protection against local corrosion phenomena.

  1. New alloying systems for ferrous powder metallurgy precision parts

    Directory of Open Access Journals (Sweden)

    Danninger H.

    2008-01-01

    Full Text Available Traditionally, the common alloy elements for sintered steels have been Cu and Ni. With increasing requirements towards mechanical properties, and also as a consequence of soaring prices especially for these two metals, other alloy elements have also become more and more attractive for sintered steels, which make the steels however more tricky to process through PM. Here, the chances and risks of using in particular Cr and Mn alloy steels are discussed, considering the different alloying techniques viable in powder metallurgy, and it is shown that there are specific requirements in particular for sintering process. The critical importance of chemical reactions between the metal and the atmosphere is described, and it is shown that not only O2 and H2O but also H2 and even N2 can critically affect sintering and microstructural homogenization.

  2. Structural, mechanical and electrical properties of alloys in ternary Ag-Bi-Zn system

    Energy Technology Data Exchange (ETDEWEB)

    Minic, D. M.; Premovic, M. M.; Zivkovic, D. T.; Manasijevic, D. M.; Dimie, M. Z.; Petrovic, Z. R.; Markovic, S. M.

    2015-07-01

    Structural, mechanical and electrical properties of selected alloys in ternary Ag-Bi-Zn system are presented in this paper. Chosen alloys were investigated using X-Ray Diffraction (XRD), light optical microscopy, Scanning Electron Microscopy combined with Energy Dispersive Spectrometry (SEM-EDS), as well as by electrical conductivity and Brinell hardness measurements. Isolines of electrical conductivity and hardness for the entire Ag-Bi-Zn system were calculated using regression models. (Author)

  3. Gating System Design for Casting thin Aluminium Alloy (Al-Si Plates

    Directory of Open Access Journals (Sweden)

    Victor ANJO

    2013-11-01

    Full Text Available The main problems caused by improper gating are entrained aluminium oxide films, cuts and washes, low casting yield and entrapped gas. This study describes the design of a gating system to produce thin Aluminium cast alloy plates of different sizes and thicknesses of 4mm, 6mm, 8mm, and 10mm using the non-pressurized gating with ratio of 1:4:4 and green sand moulding technique. The gating design was based on the laws of fluid mechanics and empirical rules of gating for non ferrous metals. The equipments used for this experiment includes; a coal fired crucible furnace and an X-Ray machine. Materials used include; silica sand, clay, wood, glue and Aluminium alloy scraps. The experimental procedure involved: the gating design calculations, construction of wooden pattern and gating; using the wooden pattern and gating to produce the mould cavities and gating; melting, melt treatment and pouring of melt in the sand mould to produce the casting. The plate castings after removal from mould were visually examined for surface defects and after fettling and cleaning X-Ray radiography was used to find the internal soundness of the castings. From the results obtained in the experiment, it was found that there were no internal defects and quality castings were produced.

  4. Processing Parameters Optimization for Material Deposition Efficiency in Laser Metal Deposited Titanium Alloy

    Science.gov (United States)

    Mahamood, Rasheedat M.; Akinlabi, Esther T.

    2016-03-01

    Ti6Al4V is an important Titanium alloy that is mostly used in many applications such as: aerospace, petrochemical and medicine. The excellent corrosion resistance property, the high strength to weight ratio and the retention of properties at high temperature makes them to be favoured in most applications. The high cost of Titanium and its alloys makes their use to be prohibitive in some applications. Ti6Al4V can be cladded on a less expensive material such as steel, thereby reducing cost and providing excellent properties. Laser Metal Deposition (LMD) process, an additive manufacturing process is capable of producing complex part directly from the 3-D CAD model of the part and it also has the capability of handling multiple materials. Processing parameters play an important role in LMD process and in order to achieve desired results at a minimum cost, then the processing parameters need to be properly controlled. This paper investigates the role of processing parameters: laser power, scanning speed, powder flow rate and gas flow rate, on the material utilization efficiency in laser metal deposited Ti6Al4V. A two-level full factorial design of experiment was used in this investigation, to be able to understand the processing parameters that are most significant as well as the interactions among these processing parameters. Four process parameters were used, each with upper and lower settings which results in a combination of sixteen experiments. The laser power settings used was 1.8 and 3 kW, the scanning speed was 0.05 and 0.1 m/s, the powder flow rate was 2 and 4 g/min and the gas flow rate was 2 and 4 l/min. The experiments were designed and analyzed using Design Expert 8 software. The software was used to generate the optimized process parameters which were found to be laser power of 3.2 kW, scanning speed of 0.06 m/s, powder flow rate of 2 g/min and gas flow rate of 3 l/min.

  5. Heavy vehicle propulsion system materials program semiannual progress report for April 1999 through September 1999

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.

    2000-01-01

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks.

  6. Building Self-Healing Alloy Architecture for Stable Sodium-Ion Battery Anodes: A Case Study of Tin Anode Materials.

    Science.gov (United States)

    Mao, Jianfeng; Fan, Xiulin; Luo, Chao; Wang, Chunsheng

    2016-03-23

    The rational design of anode materials is a challenge in developing sodium ion batteries. Alloy anodes provide high gravimetric and volumetric capacities but suffer the short cycle life as a result of the continuous and accumulated pulverization, resulting from a large volume change during the cycling process. Herein, using pure Sn, an irreversible conversion reaction combined with an alloy reaction (SnO), and a reversible conversion reaction combined with an alloy reaction (Sn4P3) as samples, we demonstrate that the pulverization and aggregation of the alloy anode can be partially recovered and the accumulation of pulverization and aggregation during charge/discharge cycles can be terminated using a reversible conversion reaction combined with an alloy reaction. The cycling stability of three Sn-based anodes increases in order of Sn4P3 > SnO > Sn. The enhancement in Sn4P3 can be attributed to a reversible reaction of Sn4P3 + 9Na ↔ 4Sn + 3Na3P, which repairs the cracks, damage, and aggregation of Sn particles that occurred in the alloy process of 4Sn + 15Na ↔ Na15Sn4 during cycling and, hence, terminates the pulverization. The repair mechanism looks like the self-healing feature in nature, where the damage can be healed by itself. Therefore, the suggested mechanism can be called self-healing, while the repaired anode can be termed as the self-healing anode. The use of self-healing strategies to build an electrode architecture is new and highly desirable because it can increase the cycle life and provide a general approach toward stable electrode materials. PMID:26937998

  7. Study of the titanium alloys surfaces used in orthopaedic systems

    International Nuclear Information System (INIS)

    Total hip prosthesis (THP) is a highly successful orthopaedic device. However, its durability is generally limited to a few decades due to difficult conditions in the human body and huge demands it is subjected to. A hip prosthesis is deteriorating due to high surface pressures caused by mechanical movements of the body. The aim of this project is to improve the characteristics of hip prostheses, in order to increase their functionality and their life span. This paper presents an analysis regarding the topography and tribological parameters of femoral heads structures and of femoral heads coated with TiN. We studied the tribological properties of the surfaces of some femoral heads made of Ti alloys or coated with TiN. These femoral heads were obtained from some prostheses after revision surgery. Afterwards, we used TiN nanostructured coatings for reducing the wear process. TiN thin films were deposited using physical vapour deposition (PVD) and some scratch tests have been realized on these coatings surfaces. The study of coatings surfaces was made using atomic force microscopy (AFM) that offers the possibility to obtain nanometric 3D control of thin films. Main result of these researches is that used coatings offer the possibility to improve the system properties. (authors)

  8. Numerical simulation of influence of material parameters on splitting spinning of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    HUANG Liang; YANG He; ZHAN Mei; HU Li-jin

    2008-01-01

    During the splitting spinning process,the material parameters of disk blank have a significant effect on the determination of forming parameters and the quality of deformed blank.The influence laws of material parameters,including yield stress.hardening exponent and elastic modulus,on splitting spinning force,splitting spinning moment,degree of inhomogeneous deformation and quality of flange (average thickness and average deviation angle) were investigated by 3D-FE numerical simulation based on elasto-plastic dynamic explicit FEM under ABAQUS/Explicit environment.The results show that.the splitting spinning force and the splitting spinning moment increase wim the increase of yield stress.hardening exponent and elastic modulus.The degree of inhomogeneous deformation increases with the decrease of yield stress and hardening exponent and the increase of elastic modulus.The average thickness of flange increases with the decrease of yield stress and the increase of hardening exponent and elastic modulus.The average deviation angle of upper surface increases with the increase of yield stress and the decrease of hardening exponent and elastic modulus.The average deviation angle of lower surface increases with the decrease of yield stress.hardening exponent and elastic modulus.Meanwhile,the corresponding variation ranges are given.The achievements may serve as an important guide for selecting the reasonable processing parameters of splitting spinning based on different aluminum alloys,and are very significant for optimum design and precision control of the splitting spinning process.

  9. Microsegregation of oxygen in Zr-2.5Nb alloy materials

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, R. [AECL Research, Pinawa, Manitoba (Canada); Jackman, J.A. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.

    1996-02-01

    Oxygen partitioning between the primary-{alpha} and {beta} phases during heating at an ({alpha} + {beta}) temperature was investigated in a Zr-2.5 Nb alloy containing about 1,100 ppm (wt) oxygen. Standard pressure tubes used in CANDU reactors have been produced from this material by hot extrusion of billets after preheating in the ({alpha} + {beta}) temperature range. Secondary ion mass spectroscopy (SIMS) was found most suitable for oxygen mapping and for determining quantitatively the extent of preferential oxygen enrichment of primary-{alpha} grains in pressure tube samples previously subjected to experimental preheat treatments at an ({alpha} + {beta}) temperature of 870 C for different soak times up to 24 hours. For the ({alpha} + {beta})-treated materials, the oxygen concentration in the primary-{alpha} grains increased with soak time, reaching up to about 8 times the concentration in the primary-{beta} matrix region. Samples from two standard pressure tubes with different fracture toughness properties were also examined. Significant differences between these tubes were found in their primary-{alpha} grain size and in the levels of oxygen enrichment of the {alpha} grains, which could provide an explanation for the difference in the toughness of these tubes.

  10. Prediction of Material removal rate for Aluminum BIS-24345 Alloy in wire-cut EDM

    Directory of Open Access Journals (Sweden)

    PUJARI SRINIVASA RAO

    2010-12-01

    Full Text Available In the present work, the parametric optimization method using Taguchi’s robust design is proposed for wire-cut electric discharge machining of Aluminum BIS-24345 alloy. In the recent past this material gained dominance, where high strength and/or hardness is required at elevated temperatures. So, experimentation has been done by using Taguchi’s L18 (21x37 orthogonal array. Each experiment was conducted under different conditions of pulse on time, pulse off time, peak current, flushing pressure of dielectric fluid, wire feed rate, wire tension, spark gap voltage and servo feed setting. The response of material removal rate is considered for improving themachining efficiency. Optimal combinations of parameters were obtained by this method. Mathematical and artificial neural network models has been developed relating the machining performance and process parameters. The study shows that the Taguchi’s method is suitable to solve the stated problem with minimum number of trails as compared with a full factorial design.

  11. Market Opportunity of Some Aluminium Silicon Alloys Materials through Changing the Casting Process

    Directory of Open Access Journals (Sweden)

    Delfim SOARES

    2012-08-01

    Full Text Available Fatigue is considered to be the most common mechanism by which engineering components fail, and it accounts for at least 90% of all service failures attributed to mechanical causes. Mechanical properties (tensile strength, tensile strain, Young modulus, etc as well as fatigue properties (fatigue life are very dependent on casting method. The most direct effects of casting techniques are on the metallurgical microstructure that bounds the mechanical properties. One of the important variables affected by the casting technique is the cooling rate which is well known to strongly restrict the microstructure. In the present research has been done a comparison of fatigue properties of two aluminum silicon alloys obtained by two casting techniques. It was observed that the fatigue life is increasing with 24% for Al12Si and 31% for AL18Si by using centrifugal casting process instead of gravity casting. This increasing in fatigue life means that a component tailored from materials obtained by centrifugal casting will stay longer in service. It was made an estimation of the time required to recover the costs of technology in order to use the centrifuge process that will allow to obtain materials with improved properties. The amortization can be achieved by using two different marketing techniques: through the release of the product at the old price and with much longer life of the component which means "same price - longer life", or increasing price, by highlighting new product performance which means "higher price - higher properties".

  12. Irradiation damage behavior of low alloy steel wrought and weld materials

    International Nuclear Information System (INIS)

    A study was undertaken to evaluate the irradiation damage response of several different types of low alloy steel. The materials included vitange type ASTM A302 Grade B (A302B) plates and welds containing different nickel (Ni) and copper (Cu) concentrations, 3.5% Ni steels similar to ASTM A508 Class 4, welds containing about 1% Ni (similar to type 105S), and 3.5% Ni steels with 'superclean' composition (extremely low phosphorus, sulfur, manganese and silicon). To determine irradiation damage behavior, all materials were irradiated at several different irradiation damage levels ranging from 0.0003 dpa to 0.06 dpa at an irradiation damage levels ranging from 0.003 dpa to 0.06 dpa at an irradiation temperature of about 232 degrees C (450 degrees F). Complete Charpy V-notch impact energy transition temperature curves were generated for all materials before and after irradiation to determine the transition temperature at 41J (30 ft-lb) or 47J (35 ft-lb) and the upper shelf energy. The irradiation damage behavior was measured by the shift in the Charpy 41J or 47J transition temperature (ΔTT41J or ΔTT47J) and lowering of the upper shelf Charpy energy at a given irradiation damage level. It was found that chemical composition greatly influenced irradiation damage behavior. The highest irradiation damage (greatest ΔTT) was found in an A302B type weld contaiNing 1.28% Ni and 0.20% CU while the least irradiation damage was found in the 3.5% Ni, 0.05% Cu, superclean wrought materials

  13. PAMTRAK: A personnel and material tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Anspach, D.A. [Sandia National Labs., Albuquerque, NM (United States); Anspach, J.P. [Allied-Signal, Inc., Albuquerque, NM (United States). Kansas City Operations; Walters, B.G. [Argonne National Lab., Idaho Falls, ID (United States); Crain, B. Jr. [Science Applications International Corp., Aiken, SC (United States)

    1996-06-01

    There is a need for an automated system for protecting and monitoring sensitive or classified parts and material. Sandia has developed a real-time personnel and material tracking system (PAMTRAK) that has been installed at selected DOE facilities. It safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. It includes remote control and alarm display capabilities and a complementary program in Keyhole to display measured material attributes remotely. This paper describes the design goals, the system components, current installations, and the benefits a site can expect when using PAMTRAK.

  14. PAMTRAK: A personnel and material tracking system

    International Nuclear Information System (INIS)

    There is a need for an automated system for protecting and monitoring sensitive or classified parts and material. Sandia has developed a real-time personnel and material tracking system (PAMTRAK) that has been installed at selected DOE facilities. It safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. It includes remote control and alarm display capabilities and a complementary program in Keyhole to display measured material attributes remotely. This paper describes the design goals, the system components, current installations, and the benefits a site can expect when using PAMTRAK

  15. Materials And Processes Technical Information System (MAPTIS) LDEF materials database

    Science.gov (United States)

    Davis, John M.; Strickland, John W.

    1992-01-01

    The Materials and Processes Technical Information System (MAPTIS) is a collection of materials data which was computerized and is available to engineers in the aerospace community involved in the design and development of spacecraft and related hardware. Consisting of various database segments, MAPTIS provides the user with information such as material properties, test data derived from tests specifically conducted for qualification of materials for use in space, verification and control, project management, material information, and various administrative requirements. A recent addition to the project management segment consists of materials data derived from the LDEF flight. This tremendous quantity of data consists of both pre-flight and post-flight data in such diverse areas as optical/thermal, mechanical and electrical properties, atomic concentration surface analysis data, as well as general data such as sample placement on the satellite, A-O flux, equivalent sun hours, etc. Each data point is referenced to the primary investigator(s) and the published paper from which the data was taken. The MAPTIS system is envisioned to become the central location for all LDEF materials data. This paper consists of multiple parts, comprising a general overview of the MAPTIS System and the types of data contained within, and the specific LDEF data element and the data contained in that segment.

  16. Materials corrosion of high temperature alloys immersed in 600C binary nitrate salt.

    Energy Technology Data Exchange (ETDEWEB)

    Kruizenga, Alan Michael; Gill, David Dennis; LaFord, Marianne Elizabeth

    2013-03-01

    Thirteen high temperature alloys were immersion tested in a 60/40 binary nitrate salt. Samples were interval tested up to 3000 hours at 600ÀC with air as the ullage gas. Chemical analysis of the molten salt indicated lower nitrite concentrations present in the salt, as predicted by the equilibrium equation. Corrosion rates were generally low for all alloys. Corrosion products were identified using x-ray diffraction and electron microprobe analysis. Fe-Cr based alloys tended to form mixtures of sodium and iron oxides, while Fe-Ni/Cr alloys had similar corrosion products plus oxides of nickel and chromium. Nickel based alloys primarily formed NiO, with chromium oxides near the oxide/base alloy interface. In625 exhibited similar corrosion performance in relation to previous tests, lending confidence in comparisons between past and present experiments. HA230 exhibited internal oxidation that consisted of a nickel/chromium oxide. Alloys with significant aluminum alloying tended to exhibit superior performance, due formation of a thin alumina layer. Soluble corrosion products of chromium, molybdenum, and tungsten were also formed and are thought to be a significant factor in alloy performance.

  17. On the effects of geometry, defects, and material asymmetry on the mechanical response of shape memory alloy cellular lattice structures

    Science.gov (United States)

    Karamooz Ravari, M. R.; Nasr Esfahani, S.; Taheri Andani, M.; Kadkhodaei, M.; Ghaei, A.; Karaca, H.; Elahinia, M.

    2016-02-01

    Shape memory alloy (such as NiTi) cellular lattice structures are a new class of advanced materials with many potential applications. The cost of fabrication of these structures however is high. It is therefore necessary to develop modeling methods to predict the functional behavior of these alloys before fabrication. The main aim of the present study is to assess the effects of geometry, microstructural imperfections and material asymmetric response of dense shape memory alloys on the mechanical response of cellular structures. To this end, several cellular and dense NiTi samples are fabricated using a selective laser melting process. Both cellular and dense specimens were tested in compression in order to obtain their stress-strain response. For modeling purposes, a three -dimensional (3D) constitutive model based on microplane theory which is able to describe the material asymmetry was employed. Five finite element models based on unit cell and multi-cell methods were generated to predict the mechanical response of cellular lattices. The results show the considerable effects of the microstructural imperfections on the mechanical response of the cellular lattice structures. The asymmetric material response of the bulk material also affects the mechanical response of the corresponding cellular structure.

  18. Computerized reactor pressure vessel materials information system

    International Nuclear Information System (INIS)

    A computerized information system for storage and retrieval of reactor pressure vessel materials data was established, as part of Task Action Plan A-11, Reactor Vessel Materials Toughness. Data stored in the system are necessary for evaluating the resistance of reactor pressure vessels to flaw-induced fracture. This report includes (1) a description of the information system; (2) guidance on accessing the system; and (3) a user's manual for the system

  19. Creep-fatigue effects in structural materials used in advanced nuclear power generating systems

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, C. R.

    1980-01-01

    Various aspects of time-dependent fatigue behavior of a number of structural alloys in use or planned for use in advanced nuclear power generating systems are reviewed. Materials included are types 304 and 316 stainless steel, Fe-2 1/4 Cr-1 Mo steel, and alloy 800H. Examples of environmental effects, including both chemical and physical interaction, are presented for a number of environments. The environments discussed are high-purity liquid sodium, high vacuum, air, impure helium, and irradiation damage, including internal helium bubble generation.

  20. The use of Spark Plasma Sintering to fabricate a two-phase material from blended aluminium alloy scrap and gas atomized powder

    OpenAIRE

    Paraskevas, Dimos; Vanmeensel, Kim; Vleugels, Jef; Dewulf, Wim; Duflou, Joost

    2015-01-01

    Recently innovative solid state / 'meltless' recycling techniques have been developed and proposed for the consolidation of aluminium alloy scrap, aiming both at energy and material savings by eliminating the melting step. In this context, a powder metallurgy route is examined as a solid state recycling technique for the fabrication of a two-phase material via Spark Plasma Sintering. By mixing aluminium atomized powder and machining chips of the same alloy, a two-phase material was produced, ...

  1. Intermetallic eutectic alloys in the Ni-Al-Zr system with attractive high temperature properties

    Directory of Open Access Journals (Sweden)

    Tiwary Chandrasekhar

    2014-01-01

    Full Text Available We describe a group of alloys with ultrahigh strength of about 2 GPa at 700°C and exceptional oxidation resistance to 1100°C. These alloys exploit intermetallic phases with stable oxide forming elements that combine to form fine nanometric scale structures through eutectic transformations in ternary systems. The alloys offer engineering tensile plasticity of about 4% at room temperature though both conventional dislocation mechanisms and twinning in the more complex intermetallic constituent, along with slip lengths that are restricted by the interphase boundaries in the eutectics.

  2. Magnetic properties of X-Pt (X=Fe,Co,Ni) alloy systems

    OpenAIRE

    Paudyal, Durga; Saha-Dasgupta, Tanusri; Mookerjee, Abhijit

    2003-01-01

    We have studied the electronic and magnetic properties of Fe-Pt, Co-Pt and Ni-Pt alloy systems in ordered and disordered phases. The influence of various exchange-correlation functionals on values of equilibrium lattice parameters and magnetic moments in ordered Fe-Pt, Co-Pt and Ni-Pt alloys have been studied using linearized muffin-tin orbital method. The electronic structure calculations for the disordered alloys have been carried out using augmented space recursion technique in the framewo...

  3. Identification of salt-alloy combinations for thermal energy storage applications in advanced solar dynamic power systems

    Science.gov (United States)

    Whittenberger, J. D.; Misra, A. K.

    Thermodynamic calculations based on the available data for flouride salt systems reveal that a number of congruently melting compositions and eutectics exist which have the potential to meet the lightweight, high energy storage requirements imposed for advanced solar dynamic systems operating between about 1000 and 1400 K. Compatibility studies to determine suitable containment alloys to be used with NaF-22CaF2-13MgF2, NaF-32CaF2, and NaF-23MgF2 have been conducted at the eutectic temperature + 25 K for each system. For these three NaF-based eutectics, none of the common, commercially available high temperature alloys appear to offer adequate corrosion resistance for a long lifetime; however mild steel, pure nickel and Nb-1Zr could prove useful. These latter materials suggest the possibility that a strong, corrosion resistant, nonrefractory, elevated temperature alloy based on the Ni-Ni3Nb system could be developed.

  4. Corrosion Behavior and Strength of Dissimilar Bonding Material between Ti and Mg Alloys Fabricated by Spark Plasma Sintering

    Directory of Open Access Journals (Sweden)

    Patchara Pripanapong

    2016-08-01

    Full Text Available Ti and solution treated Mg alloys such as AZ31B (ST, AZ61 (ST, AZ80 (ST and AZ91 (ST were successfully bonded at 475 °C by spark plasma sintering, which is a promising new method in welding field. The formation of Ti3Al intermetallic compound was found to be an important factor in controlling the bonding strength and galvanic corrosion resistance of dissimilar materials. The maximum bonding strength and bonding efficiency at 193 MPa and 96% were obtained from Ti/AZ91 (ST, in which a thick and uniform nano-level Ti3Al layer was observed. This sample also shows the highest galvanic corrosion resistance with a measured galvanic width and depth of 281 and 19 µm, respectively. The corrosion resistance of the matrix on Mg alloy side was controlled by its Al content. AZ91 (ST exhibited the highest corrosion resistance considered from its corrode surface after corrosion test in Kroll’s etchant. The effect of Al content in Mg alloy on bonding strength and corrosion behavior of Ti/Mg alloy (ST dissimilar materials is discussed in this work.

  5. Analysis of causes inappropriate registrations in the computer system control high-grade alloys casting

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2010-10-01

    Full Text Available In the aim of improvement of the process of the registration of characteristics TDA (thermal and derivative analysis in the industry as and the Process Failure Mode and Effects Analysis was carry out on investigative stands using the Computer System of Quality Control Alloys (CSQCA. The necessity of the operators of the system, the workers of section QC and the managers of production in the aim of realiza-tion of and emphasising the meaning of the warning of the methodic of measurements using TDA periodical training results from intro-duced analyses. The mechanization and automation (in well-founded cases e.g.: in the process of pressure die casting the station of cast the probe, the repeatability of conditions can guarantee cast the probe ATD (i.e. the speeds cast the probe, proper heating of pouring cup dosing metal, the quantities of the metal poured to probe. Proper designing the Station of Cast TDA Probe isolates the tripod and probe itself from man-made interference generated by the closest surroundings and the more frequent measurements of the temperature of the liquid metal in landle, they make possible avoidance of the basic causes of incorrect the TDA registrations. Work this makes up training materials for the operators of the system and the managers is responsible for the control of the quality of alloys the TDA method in the foundry. The introduced list of the most frequent irregularities, during the registration the TDA, it will make possible the quick identification of their causes and undertaking of suitable preventive workings to the operators of the system.

  6. Glass Formation in Ni-Zr-(Al Alloy Systems

    Directory of Open Access Journals (Sweden)

    Lanping Huang

    2013-01-01

    Full Text Available Structural and thermal properties of binary Ni100-xZrx (30alloys obtained by melt spinning and copper mold casting methods were investigated. The fully amorphous samples in a bulk form cannot be obtained in the binary Ni-Zr alloys over a wide composition range, though they have Tg/Tl and γ values close to or even higher than those of the binary Cu-Zr bulk metallic glasses (BMGs. The low thermal stability of the supercooled liquid against crystallization and the formation of the equilibrium crystalline phases with a high growth rate are responsible for their low glass-forming abilities (GFAs. Relatively low thermal conductivities of Ni-based alloys are also considered to be another factor to limit their GFAs. The GFA of the binary Ni65.5Zr34.5 alloy alloyed with 4% or 5% Al was enhanced, and a fully glassy rod with a diameter of 0.5 mm was formed.

  7. Estimating the Eutectic Composition of Simple Binary Alloy System Using Linear Geometry

    Directory of Open Access Journals (Sweden)

    Muhammed Olawale Hakeem AMUDA

    2008-06-01

    Full Text Available A simple linear equation was developed and applied to a hypothetical binary equilibrium diagram to evaluate the eutectic composition of the binary alloy system. Solution of the equations revealed that the eutectic composition of the case study Pb – Sn, Bi – Cd and Al – Si alloys are 39.89% Pb, 60.11% Sn, 58.01% Bi, 41.99% Cd and 90.94% Al, 9.06% Si respectively. These values are very close to experimental values. The percent deviation of analytical values from experimental values ranged between 2.87 and 5% for the three binary systems considered, except for Si – Al alloy in which the percent deviation for the silicon element was 22%.It is concluded that equation of straight line could be used to predict the eutectic composition of simple binary alloys within tolerable experimental deviation range of 2.5%.

  8. Material Instabilities in Particulate Systems

    Science.gov (United States)

    Goddard, J. D.

    1999-01-01

    Following is a brief summary of a theoretical investigation of material (or constitutive) instability associated with shear induced particle migration in dense particulate suspensions or granular media. It is shown that one can obtain a fairly general linear-stability analysis, including the effects of shear-induced anisotropy in the base flow as well as Reynolds dilatancy. A criterion is presented here for simple shearing instability in the absence of inertia and dilatancy.

  9. Microstructural characterisation of Ti-Nb-(Fe-Cr) alloys obtained by powder metallurgy

    OpenAIRE

    Amigó Mata, Angèlica; Zambrano, Jenny Cecilia; Martínez, S; Amigó Borrás, Vicente

    2014-01-01

    beta alloys based on the Ti Nb alloy system are of growing interest to the biomaterial community. The addition of small amounts of Fe and Cr further increases beta-phase stability, improving the properties of Ti Nb alloy. However, PM materials sintered from elemental powders are inhomogeneous due to restricted solid state diffusion and mechanical alloying provides a route to enhance mixing and lemental diffusion. The microstructural characteristics and bend strength of Ti Nb (Fe Cr) alloys ...

  10. High-temperature shape memory alloys based on the RuNb system

    International Nuclear Information System (INIS)

    Many applications of shape memory alloys (SMAs) require the development of alloys with high martensitic transformation (MT) temperatures. Among the different systems for high temperature SMAs, equiatomic RuNb alloys demonstrate both shape memory effect (SME) and MT temperatures above 800 deg. C. This work investigates Ru50-xNb50+x (at.%) alloys and shows that Nb content significantly affects the MT behavior. Alloys near the equiatomic composition (x = 0, 2, 4) undergo two displacive transformations on cooling: β (B2) → β' (body centered tetragonal) → β'' (monoclinic). The Ru45Nb55 alloy exhibits a single transition from cubic to tetragonal on cooling. This MT gives rise to a highly twinned microstructure with a (0 1 1) compound-twinning mode and is considered to be responsible for the SME in both types of alloys. The reorientation of martensite variants during deformation has been confirmed through scanning electron microscopy of compression specimens. A promising shape memory behavior is obtained through three-point bend tests performed both in the β' and β'' phases

  11. Considerations on the performance and fabrication of candidate materials for the Yucca Mountain repository waste packages highly corrosion resistant nickel-base and titanium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dalder, E; Goldberg, A

    1995-11-30

    Among the metallurgical factors that affect the performance of a material in a given environment are alloy composition, alloy segregation, depletion of alloying elements, non-uniform microstructures, precipitation leading to an increase in susceptibility to corrosion as well as decreases in ductility, residual plastic deformation, and residual stresses. Precipitation often occurs preferentially at grain boundaries, causing depletion of critical elements in regions adjacent to these boundaries. Continuous grain-boundary precipitates can lead to drops in ductility and toughness. The presence of non-metallic inclusions, if excessive and/or segregated, can also cause embrittlement. Segregation of alloying elements can result in localized galvanic action. Depletion of alloying elements as well as segregation can result in reductions in the concentrations of critical elements below those necessary to resist localized corrosion. Segregation and alloy depletion can also facilitate precipitation that could lead to embrittlement.

  12. Methodology for assessing systems materials requirements

    Energy Technology Data Exchange (ETDEWEB)

    Culver, D.H.; Teeter, R.R.; Jamieson, W.M.

    1980-01-01

    A potential stumbling block to new system planning and design is imprecise, confusing, or contradictory data regarding materials - their availability and costs. A methodology is now available that removes this barrier by minimizing uncertainties regarding materials availability. Using this methodology, a planner can assess materials requirements more quickly, at lower cost, and with much greater confidence in the results. Developed specifically for energy systems, its potential application is much broader. This methodology and examples of its use are discussed.

  13. Ultrasonic properties of low solvus high refractory (LSHR) super alloy disk material

    International Nuclear Information System (INIS)

    Measurements are made for ultrasonic linear and nonlinear properties of the powder metallurgy disk alloy LSHR material designed with a relatively low γ' precipitate solvus temperature and high refractory element content. This allows versatile heat treatment processing which results in high tensile, creep and fatigue properties depending on the grain size controlled through proper selection of solution heat treatment temperatures relative to the γ' precipitate solvus temperature. Sound velocity and attenuation for both longitudinal and shear modes at various frequencies from 5 to 20 MHz help to identify and quantify the size of transition zone nondestructively between the small grain (∼10 μm) and the large grain (∼100 μm) zones. The shear wave velocity measurements taken by aligning the transducer polarization direction parallel and perpendicular to the grain transition direction reveal some results that we do not fully understand at this time and will be the basis of future research. Similarly, measurements of the acoustic nonlinearity parameter show some variations that may originate from uncertain sources.

  14. Influence of Temperature on the Strain Controlled Fatigue Behaviour of Alloy 690 Tube Material

    Energy Technology Data Exchange (ETDEWEB)

    Johan Frodigh; Guocai Chai; Ping Liu [Sandvik Materials Technology, Sandviken (Sweden)

    2004-07-01

    Strain controlled fatigue tests for hot-extruded tube material of Alloy 690 (Sandvik Sanicro 69) have been performed at room temperature (RT) and at elevated temperature (204 deg. C). The influences of temperature on the cyclic deformation behaviour and the fatigue life have been investigated. The influence of temperature on the fatigue life is relatively small in the temperature range investigated. However, the fatigue behaviour at elevated temperature is quite different from that at RT. A second cyclic strain hardening was observed at 204 deg. C. The possible mechanisms have been investigated using transmission electron microscopy. Besides dislocation mechanism, the interactions between moving dislocations and stacking faults and between interstitial atoms and moving dislocations could also contribute to this secondary cyclic strain hardening. The formation of micro-twins during cyclic loading at 204 deg. C and its influence on the cyclic stress-strain response were also discussed. Temperature affects both fatigue crack initiation and propagation behaviour. Increase in temperature promotes duplex slipping process, which causes the formation of striation. (authors)

  15. SAW surfacing of low-alloyed steel with super-ferrite additional material

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2009-10-01

    Full Text Available Purpose: of these researches was to investigate influence of heat input in SAW surfacing of low-alloyed steel with super-ferrite filler material on quality of deposits.Design/methodology/approach: the quality of single and multilayer, stringer beads was assessed by metallographic examinations, stresses measurements and hardness tests.Findings: due to the fact that it was used at automated surfacing stand, the analysis of properties of the deposits was performed for single and multilayer, stringer beads.Research limitations/implications: for complete information about tested deposits it is needed to compare deposits properties with other technologies of super-ferrite deposits surfacing.Practical implications: results of this paper is an optimal range of parameters for surfacing of single and multilayer, stringer beads of super-ferrite layers.Originality/value: the researches (macro- and micro-observations, hardness tests, stresses distribution tests were provided for surfacing of single and multilayer, stringer beads, and the results were compared. The influence of heat input on layers properties and theirs structure was defined.

  16. CMB-8 material balance system

    International Nuclear Information System (INIS)

    We describe the automated nondestructive assay (NDA) system installed at the Los Alamos Scientific Laboratory (LASL) Group CMB-8 uranium recovery facility. A random driver (RD) is used to measure the 235U content of various solids while a uranium solution assay system (USAS) measures the 235U or total uranium content of solutions over a concentration range of a few ppM to 400 g/l. Both instruments are interfaced to and controlled by a single minicomputer. The measurement principles, mechanical specifications, system software description, and operational instructions are described

  17. Task 2: Materials for Advanced Boiler and Oxy-combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Holcolm, Gordon R.; McGhee, Barry

    2009-05-01

    The PowerPoint presentation provides an overview of the tasks for the project: Characterize advanced boiler (oxy-fuel combustion, biomass co-fired) gas compositions and ash deposits; Generate critical data on the effects of environmental conditions; develop a unified test method with a view to future standardization; Generate critical data for coating systems for use in advanced boiler systems; Generate critical data for flue gas recycle piping materials for oxy-fuel systems; and, Compile materials performance data from laboratory and pilot plant exposures of candidate alloys for use in advanced boiler systems.

  18. Effect of Cr, Ni and Mo on corrosion resistance of highly alloyed materials in sour well environments

    International Nuclear Information System (INIS)

    The effect of Cr, Ni and Mo on the corrosion behaviours of highly alloyed materials was investigated in simulated sour well environments. The increases of all of Cr, Ni and Mo contents increase the resistance to general and pitting corrosion. Increasing Ni content also improves the resistance to stress corrosion cracking (SCC). From the standpoint of those resistances, high Ni content as well as high Cr and Mo contents is essential to maintain the corrosion resistance in sour well environments. Surface film analysis shows there are two types of film structure, that is: Cr oxide single layer, and double layer with outer Ni sulfide and inner Cr oxide. Corrosion resistance is basically determined by the presence of surface Cr oxide film. Increasing Ni and Mo contents is considered to increase the stability of the surface film. In addition, electrochemical measurements were carried out with high alloy materials and pure metals to clarify the behaviours of Cr, Ni and Mo

  19. Kinetic study of hydrogen-material interactions in nickel base alloy 600 and stainless steel 316L through coupled experimental and numerical analysis

    International Nuclear Information System (INIS)

    defects. Concerning these H-trap site interactions, literature presents very few complete sets of kinetic data; it is therefore necessary to study and characterize these interactions in-depth. This work is composed of two interdependent parts: (i) the development of a calculation code capable to manage these H-material interactions and (ii) to extract the kinetic constants for trapping and detrapping from experimental results in order to fuel the simulation code and create a solid database. Due to the complexity of industrial materials (A600 and SS316L), 'model materials' were elaborated using a series of thermomechanical treatments allowing for the study of simplified systems and the deconvolution of the different possible trapped and interstitial hydrogen contributions. These 'model' specimens were charged with deuterium (an isotopic hydrogen tracer) by cathodic polarization. After charging, specimens were subjected to thermal desorption mass spectroscopy (TDS) analysis where the deuterium desorption flux is monitored during a temperature ramp or at an isotherm. Interstitial diffusion and kinetic trapping and detrapping constants were extracted from experimental TDS spectra using a numerical fitting routine based upon the numerical resolution of the McNabb and Foster equations. This study allowed for the determination of the hydrogen diffusion coefficient in two alloys, Ni base alloy 600 and stainless steel 316L, and the kinetic trapping and detrapping constants at two trap site types, chromium carbides and dislocations. These constants will be used to construct a kinetic database which will serve as input parameters for a numerical model for the prediction and simulation of SCC in PWRs. (author)

  20. Synthesis of Ge1-xSnx alloys by ion implantation and pulsed laser melting: Towards a group IV direct bandgap material

    Science.gov (United States)

    Tran, Tuan T.; Pastor, David; Gandhi, Hemi H.; Smillie, Lachlan A.; Akey, Austin J.; Aziz, Michael J.; Williams, J. S.

    2016-05-01

    The germanium-tin (Ge1-xSnx) material system is expected to be a direct bandgap group IV semiconductor at a Sn content of 6.5 - 11 at . % . Such Sn concentrations can be realized by non-equilibrium deposition techniques such as molecular beam epitaxy or chemical vapour deposition. In this report, the combination of ion implantation and pulsed laser melting is demonstrated to be an alternative promising method to produce a highly Sn concentrated alloy with a good crystal quality. The structural properties of the alloys such as soluble Sn concentration, strain distribution, and crystal quality have been characterized by Rutherford backscattering spectrometry, Raman spectroscopy, x ray diffraction, and transmission electron microscopy. It is shown that it is possible to produce a high quality alloy with up to 6.2 at . % Sn . The optical properties and electronic band structure have been studied by spectroscopic ellipsometry. The introduction of substitutional Sn into Ge is shown to either induce a splitting between light and heavy hole subbands or lower the conduction band at the Γ valley. Limitations and possible solutions to introducing higher Sn content into Ge that is sufficient for a direct bandgap transition are also discussed.

  1. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    Directory of Open Access Journals (Sweden)

    Bloemer Wilhelm

    2010-01-01

    Full Text Available Abstract Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68 of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years and the average weight 102.3 kg (75 to 130 kg. The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck

  2. Corrosion and Discharge Behaviors of Mg-Al-Zn and Mg-Al-Zn-In Alloys as Anode Materials

    Directory of Open Access Journals (Sweden)

    Jiarun Li

    2016-03-01

    Full Text Available The Mg-6%Al-3%Zn and Mg-6%Al-3%Zn-(1%, 1.5%, 2%In alloys were prepared by melting and casting. Their microstructures were investigated via metallographic and energy-dispersive X-ray spectroscopy (EDS analysis. Moreover, hydrogen evolution and electrochemical tests were carried out in 3.5 wt% NaCl solution aiming at identifying their corrosion mechanisms and discharge behaviors. The results suggested that indium exerts an improvement on both the corrosion rate and the discharge activity of Mg-Al-Zn alloy via the effects of grain refining, β-Mg17Al12 precipitation, dissolving-reprecipitation, and self-peeling. The Mg-6%Al-3%Zn-1.5%In alloy with the highest corrosion rate at free corrosion potential did not perform desirable discharge activity indicating that the barrier effect caused by the β-Mg17Al12 phase would have been enhanced under the conditions of anodic polarization. The Mg-6%Al-3%Zn-1.0%In alloy with a relative low corrosion rate and a high discharge activity is a promising anode material for both cathodic protection and chemical power source applications.

  3. Comparison of fracture properties in SA508 Gr.3 and Gr.4N high strength low alloy steels for advanced pressure vessel materials

    International Nuclear Information System (INIS)

    Nuclear power systems are moving to a larger capacity or smaller modular type. In any either case, advanced pressure vessel materials with high strength and toughness are definitely needed for an optimization of the design and construction, as well as the long-term operation. In this paper, two candidate materials, both of which are within the current ASME specifications of SA508 steel forging, are compared from the view point of fracture resistance properties for a nuclear pressure vessel steel. The microstructure and mechanical properties of SA508 Gr.3 Cl.1, Cl.2, and Gr.4N steels were also characterized. The predominant microstructure of SA508 Gr.4N model alloy is tempered martensite, while SA508 Gr.3 Cl.1 and Cl.2 steels show a tempered upper bainitic structure. SA508 Gr. 4N model alloy showed the best strength and transition behavior among the three types of SA508 steel. SA508 Gr.3 Cl.2 steel has good strength and fracture toughness, but there is a decrease in the upper-self energy. The fracture resistance and fatigue crack growth rate of SA508 Gr.3 Cl.2 and Gr.4N steels were comparable to those of SA508 Gr.3 Cl.1 steel. In terms of mechanical properties, SA508 Gr.4N steel is a fascinating material for the pressure vessel application although it still needs verification on the aging behavior such as the irradiation embrittlement resistance

  4. On Using Materiality in Information Systems Development

    DEFF Research Database (Denmark)

    Carugati, Andrea

    This research brief presents a discussion on the use of the concept of materiality and material knowing in information systems development (ISD). The discussion addresses some of the practical problems still plaguing ISD, augmenting existing ISD methodologies with contributions from systems theory...... and in particular the idea of inquiring systems. The discussion builds on different contemporary concepts that are rooted in the inquiring systems idea: the notion of stakeholders (designer, client, user and their interchanging roles), the notion boundary object and boundary spanners, and the notion of materiality...... as scaffold of knowledge. Through the example taken from a case study of a complex and innovative systems development we outline two design principles to be embedded in modular fashion in ISD processes: (1) whenever possible start ISD efforts by developing a graphical simulator of the material environment...

  5. High-temperature alloys and thermal spray coatings for energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Al-Taie, I.; Brigham, R.J.; Lafreniere, Y. [CANMET, Ottawa, Ontario (Canada). Metals Technology Lab.

    1995-12-31

    Materials continue to be of primary concern as the potential limiting factor for the implementation of coal gasification technology in Canada. Superalloys and thermal spray coatings for syngas coolers represent one class of materials where a knowledge of general trends in oxidation/sulphidation and erosion resistance for a range of chemical compositions is thought to be essential for reliable operation of such technology. Alloy 800H, 304, 310, T91, Monit and Sanicro 28 along with four types of coatings (Al{sub 2}O{sub 3}, Cr{sub 2}O{sub 3}, Al{sub 2}O{sub 3}/Ni3Al and CoCrAlYNi) applied on each one of the above alloys have been subjected to a series of exposures (6 {times} 250h cycles) in two different gas mixtures containing CO, H{sub 2}, H{sub 2}S, H{sub 2}O at 600 C. The kinetics and mechanisms of corrosion and erosion of these alloys have been investigated using Scanning Electron Microscopy and surface analytical techniques. Thermal spray coatings of ceramic and composite materials were found to be problematic on austenitic alloys because of spallation. Ceramic, composite and metallic coatings adhered well to the ferritic alloy. Nickel aluminide in combination with aluminum oxide as a composite did not display the expected high degree of corrosion resistance. High temperature erosion rates were found to be low on the bare superalloys and to be decreased by highly alloyed metallic coatings such as CoCrAlYNi, FeCrAlYMo and NiCrAlYCo. Ceramic and composite coatings were ineffective in reducing erosion rates because of spallation and reactivity in the simulated gasification environment.

  6. Template-free electrodeposition of AlFe alloy nanowires from a room-temperature ionic liquid as an anode material for Li-ion batteries.

    Science.gov (United States)

    Chen, Gang; Chen, Yuqi; Guo, Qingjun; Wang, Heng; Li, Bing

    2016-08-15

    AlFe alloy nanowires were directly electrodeposited on copper substrates from trimethylamine hydrochloride (TMHC)-AlCl3 ionic liquids with small amounts of FeCl3 at room temperature without templates. Coin cells composed of AlFe alloy nanowire electrodes and lithium foils were assembled to characterize the alloy electrochemical properties by galvanostatic charge/discharge tests. Effects of FeCl3 concentration, potential and temperature on the alloy morphology, composition and cyclic performance were examined. Addition of Fe into the alloy changed the nanowires from a 'hill-like' bulk morphology to a free-standing morphology, and increased the coverage area of the alloy on Cu substrates. As an inactive element, Fe could also buffer the alloys' large volume changes during Li intercalation and deintercalation. AlFe alloy nanowires composed of a small amount of Fe with an average diameter of 140 nm exhibited an outstanding cyclic performance and delivered a specific capacity of about 570 mA h g(-1) after 50 cycles. This advanced template-free method for the direct preparation of high performance nanostructure AlFe alloy anode materials is quite simple and inexpensive, which presents a promising prospect for practical application in Li-ion batteries. PMID:27200436

  7. Neutron irradiation test of copper alloy/stainless steel joint materials

    OpenAIRE

    山田 弘一; 河村 弘

    2006-01-01

    As a study about the joint technology of copper alloy and stainless steel for utilization as cooling piping in International Thermonuclear Experimental Reactor (ITER), Al2O3-dispersed strengthened copper or CuCrZr was joined to stainless steel by three kinds of joint methods (casting joint, brazing joint and friction welding method) for the evaluation of the neutron irradiation effect on joints. A neutron irradiation test was performed to three types of joints and each copper alloy. The avera...

  8. Efficiency analysis system of material management

    Directory of Open Access Journals (Sweden)

    Bogusław Śliwczyński

    2012-12-01

    Full Text Available Background: Significant scope of enterprise's efficiency management is improving of material management process both the strategic and operational level. The complexity of material flow processes can lead to a threat such as distraction and disintegration of analysis focusing on many different factors influenced on effective sourcing and procurement management, transport and warehousing processes, inventory management, working capital and cash flow management. Material and methods: The presented article focuses on multidimensional and multi-criteria analysis of material management efficiency that is considered as decision support system. Authors have presented results of the research regarding ineffective material management confirm insufficient analytical supporting in various decisions of procurement operations. Results and conclusions: Based on research results authors presented in the article model of efficiency analysis system of material management.

  9. Microstructure, Elastic Modulus and Tensile Properties of Ti-Nb-O Alloy System

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the present study Ti-Nb binary alloy system was chosen because it has excellent biocompatibility as well as reasonable mechanical properties, aiming at understanding oxygen content on microstructural formation,elastic modulus and tensile properties in Ti-Nb alloy system. Small alloy buttons of 50 mm in diameter were prepared by arc melting on a water-cooled copper hearth under an argon gas atmosphere with a non-consumable tungsten electrode. The button ingots were then heat treated in a vacuum atmosphere at 1273 K for 0.5 h followed by water quenching in a specially designed heat treatment furnace. Microstructure, elastic modulus and tensile properties were investigated in order to understand the effect of oxygen content in quenched TiNb alloy system. The orthorhombic structured α″ martensite was changed to bcc structured β-phase with increasing Nb content. Interestingly, it was found that oxygen makes β-phase stable in quenched Ti-Nb alloy system. Elastic modulus values were sensitive to phase stability of constituent phases. Yield strength increased with increasing oxygen content. Details will be explained by phase formation and stability behavior.

  10. Nuclear Materials Identification System Operational Manual

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, L.G.

    2001-04-10

    This report describes the operation and setup of the Nuclear Materials Identification System (NMIS) with a {sup 252}Cf neutron source at the Oak Ridge Y-12 Plant. The components of the system are described with a description of the setup of the system along with an overview of the NMIS measurements for scanning, calibration, and confirmation of inventory items.

  11. Investigation of Effects of Neutron Irradiation on Tantalum Alloys for Radioisotope Power System Applications

    International Nuclear Information System (INIS)

    Tantalum alloys have been used by the U.S. Department of Energy as structural alloys for space nuclear power systems such as Radioisotopic Thermoelectric Generators (RTG) since the 1960s. Tantalum alloys are attractive for high temperature structural applications due to their high melting point, excellent formability, good thermal conductivity, good ductility (even at low temperatures), corrosion resistance, and weldability. A number of tantalum alloys have been developed over the years to increase high-temperature strength (Ta-10%W) and to reduce creep strain (T-111). These tantalum alloys have demonstrated sufficient high-temperature toughness to survive the increasing high pressures of the RTG's operating environment resulting from the alpha decay of the 238-plutonium dioxide fuel. However, 238-plutonium is also a powerful neutron source. Therefore, the RTG operating environment produces large amounts of 3-helium and neutron displacement damage over the 30 year life of the RTG. The literature to date shows that there has been very little work focused on the mechanical properties of irradiated tantalum and tantalum alloys and none at the fluence levels associated with a RTG operating environment. The minimum, reactor related, work that has been reported shows that these alloys tend to follow trends seen in the behavior of other BCC alloys under irradiation. An understanding of these mechanisms is important for the confident extrapolation of mechanical-property trends to the higher doses and gas levels corresponding to actual service lifetimes. When comparing the radiation effects between samples of Ta-10%W and T-111 (Ta-8%W-2%Hf) subjected to identical neutron fluences and environmental conditions at temperatures <0.3Tm (∼700 deg. C), evidence suggests the possibility that T-111 will exhibit higher levels of internal damage accumulation and degradation of mechanical properties compared to Ta-10%W

  12. Investigation of Effects of Neutron Irradiation on Tantalum Alloys for Radioisotope Power System Applications

    Science.gov (United States)

    Barklay, Chadwick D.; Kramer, Daniel P.; Talnagi, Joseph

    2007-01-01

    Tantalum alloys have been used by the U.S. Department of Energy as structural alloys for space nuclear power systems such as Radioisotopic Thermoelectric Generators (RTG) since the 1960s. Tantalum alloys are attractive for high temperature structural applications due to their high melting point, excellent formability, good thermal conductivity, good ductility (even at low temperatures), corrosion resistance, and weldability. A number of tantalum alloys have been developed over the years to increase high-temperature strength (Ta-10%W) and to reduce creep strain (T-111). These tantalum alloys have demonstrated sufficient high-temperature toughness to survive the increasing high pressures of the RTG's operating environment resulting from the alpha decay of the 238-plutonium dioxide fuel. However, 238-plutonium is also a powerful neutron source. Therefore, the RTG operating environment produces large amounts of 3-helium and neutron displacement damage over the 30 year life of the RTG. The literature to date shows that there has been very little work focused on the mechanical properties of irradiated tantalum and tantalum alloys and none at the fluence levels associated with a RTG operating environment. The minimum, reactor related, work that has been reported shows that these alloys tend to follow trends seen in the behavior of other BCC alloys under irradiation. An understanding of these mechanisms is important for the confident extrapolation of mechanical-property trends to the higher doses and gas levels corresponding to actual service lifetimes. When comparing the radiation effects between samples of Ta-10%W and T-111 (Ta-8%W-2%Hf) subjected to identical neutron fluences and environmental conditions at temperatures <0.3Tm (˜700 °C), evidence suggests the possibility that T-111 will exhibit higher levels of internal damage accumulation and degradation of mechanical properties compared to Ta-10%W.

  13. Deuterium absorption and material phase characteristics of SAES St 198 Zr-Fe Alloy

    International Nuclear Information System (INIS)

    This document reports deuterium absorption and material phase characteristics of SAES St 198 Zr-Fe Alloy (76.5% Zr). Scanning electron microscope images of polished surfaces, electron probe microanalysis, and x-ray powder diffractometry indicated the presence of a primary Zr2Fe phase with secondary phases of ZrFe2, Zr5FeSn, α-Zr, and Zr6Fe3O. A statistically designed experiment to determine the effects of temperature, time, and vacuum quality on activation of St 198 revealed that, when activated at low temperature (350C), deuterium absorption rate was slower when the vacuum quality was poor (2.5 Pa vs. 3 x 10-4 Pa). However, at higher activation temperature (500C), deuterium absorption rate was fast and was independent of vacuum quality. Deuterium pressure-composition-temperature (P-C-T) data are reported for St 198 in the temperature range 200 to 500C. The P-C-T data over the full range of deuterium loading and at temperatures of 350C and below is described an expression. At higher temperatures, one or more secondary reactions in the solid phase occur that slowly consume D2 from the gas phase. X-ray diffraction and other data suggest these reactions to be: 2 Zr2FeDx → xZrD2 + x/3 ZrFe2 + (2 - 2/3x) Zr2Fe and Zr2FeDx + (2 - 1/2x) D2 → 2 ZrD2 + Fe, where 0 2Fe formed in the first reaction accounts for the observed consumption of deuterium from the gas phase by this reaction

  14. New all aluminum alloy ultrahigh vacuum system and fittings

    International Nuclear Information System (INIS)

    The Al-ICF ALFLAT FLANGE corresponds to the ordinary stainless steel Conflat flange. The Al-ICF ALFLAT FLANGE is made of special aluminum alloy 2219-T87 by forging. It has the highest strength at elevated high temperature among all aluminum alloys as well as superior weldability and stress corrosion cracking resistivity. CrN or TiC coating on the flange surface by ion plating. The CrN or TiC treatment on the surface gave nearly protection against sticking between the knife edge of the flange and the aluminum gasket and surface scratching. Sealing surface of the knife edge for the Helicoflex is finished to a smooth mirror surface by a diamond tool. (author)

  15. Evaluation on materials performance of Hastelloy Alloy XR for HTTR uses-6. Tensile and creep properties of heat exchanger tube base materials and its welded-joints

    International Nuclear Information System (INIS)

    Tensile and creep properties of heat exchanger tube base materials and its welded-joints were investigated as a series of evaluation tests on Hastelloy Alloy XR heat exchanger tube and filler metal for the High Temperature Engineering Test Reactor (HTTR) components. As for tensile properties after thermal aging of base materials and welded joints, ductility was remarkably reduced at room temperature while it was raised at 950degC. On creep properties, the difference between base materials and welded joints in creep rupture strength was relatively small. Creep rupture elongation tended to decrease with increasing rupture time, and rupture elongation of welded joint had a tendency to be lower than that of base material. On the other hand, a comparison of plate with tube on high temperature tensile ductility after thermal aging was found to be higher in tube than in plate while its difference was slight at room temperature. As for creep properties, base materials and welded joints of tube had a tendency to be slightly shorter in rupture time at lower stress and long terms than those of plate. However, it is concluded that this is not problematic in practical uses from the fact that the rupture time in tube is comparable or greater than that of Hastelloy Alloy XR master curve and that it is much longer than that of design creep rupture strength =SR=. (author)

  16. Long-Time Stability of Ni-Ti-Shape Memory Alloys for Automotive Safety Systems

    Science.gov (United States)

    Strittmatter, Joachim; Gümpel, Paul

    2011-07-01

    In automotive a lot of electromagnetically, pyrotechnically or mechanically driven actuators are integrated to run comfort systems and to control safety systems in modern passenger cars. Using shape memory alloys (SMA) the existing systems could be simplified, performing the same function through new mechanisms with reduced size, weight, and costs. A drawback for the use of SMA in safety systems is the lack of materials knowledge concerning the durability of the switching function (long-time stability of the shape memory effect). Pedestrian safety systems play a significant role to reduce injuries and fatal casualties caused by accidents. One automotive safety system for pedestrian protection is the bonnet lifting system. Based on such an application, this article gives an introduction to existing bonnet lifting systems for pedestrian protection, describes the use of quick changing shape memory actuators and the results of the study concerning the long-time stability of the tested NiTi-wires. These wires were trained, exposed up to 4 years at elevated temperatures (up to 140 °C) and tested regarding their phase change temperatures, times, and strokes. For example, it was found that A P-temperature is shifted toward higher temperatures with longer exposing periods and higher temperatures. However, in the functional testing plant a delay in the switching time could not be detected. This article gives some answers concerning the long-time stability of NiTi-wires that were missing till now. With this knowledge, the number of future automotive applications using SMA can be increased. It can be concluded, that the use of quick changing shape memory actuators in safety systems could simplify the mechanism, reduce maintenance and manufacturing costs and should be insertable also for other automotive applications.

  17. Mo-Si alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Heatherly, L.; Wright, J.L. [Oak Ridge National Lab., TN (United States)

    1996-06-01

    The objective of this task is to develop new-generation corrosion-resistant Mo-Si intermetallic alloys as hot components in advanced fossil energy conversion and combustion systems. The initial effort is devoted to Mo{sub 5}-Si{sub 3}-base (MSB) alloys containing boron additions. Three MSB alloys based on Mo-10.5Si-1.1B (wt %), weighing 1500 g were prepared by hot pressing of elemental and alloy powders at temperatures to 1600{degrees}C in vacuum. Microporosities and glassy-phase (probably silicate phases) formations are identified as the major concerns for preparation of MSB alloys by powder metallurgy. Suggestions are made to alleviate the problems of material processing.

  18. Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

    Science.gov (United States)

    Gandin, Charles-Andre; Ratke, Lorenz

    2008-01-01

    The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

  19. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Xinzhi; He Yurong; Zheng Yan; Ma Junju; H. Inaki Schlaberg

    2014-01-01

    Actively cooled thermal protection system has great influence on the engine of a hyper-sonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA) is applied to the numerical simulation. Temper-ature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC). The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best charac-teristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are com-pared with each other and a reasonable agreement is obtained.

  20. Analytic estimation and numerical modeling of actively cooled thermal protection systems with nickel alloys

    Directory of Open Access Journals (Sweden)

    Wang Xinzhi

    2014-12-01

    Full Text Available Actively cooled thermal protection system has great influence on the engine of a hypersonic vehicle, and it is significant to obtain the thermal and stress distribution in the system. So an analytic estimation and numerical modeling are performed in this paper to investigate the behavior of an actively cooled thermal protection system. The analytic estimation is based on the electric analogy method and finite element analysis (FEA is applied to the numerical simulation. Temperature and stress distributions are obtained for the actively cooled channel walls with three kinds of nickel alloys with or with no thermal barrier coating (TBC. The temperature of the channel wall with coating has no obvious difference from the one with no coating, but the stress with coating on the channel wall is much smaller than that with no coating. Inconel X-750 has the best characteristics among the three Ni-based materials due to its higher thermal conductivity, lower elasticity module and greater allowable stress. Analytic estimation and numerical modeling results are compared with each other and a reasonable agreement is obtained.

  1. Materials Reliability Program Resistance to Primary Water Stress Corrosion Cracking of Alloys 690, 52, and 152 in Pressurized Water Reactors (MRP-111)

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H. [Framatome ANP, Inc., Lynchburg, VA (United States); Fyfitch, S. [Framatome ANP, Inc., Lynchburg, VA (United States); Scott, P. [Framatome ANP, SAS, Paris (France); Foucault, M. [Framatome ANP, SAS, Le Creusot (France); Kilian, R. [Framatome ANP, GmbH, Erlangen (Germany); Winters, M. [Framatome ANP, GmbH, Erlangen (Germany)

    2004-03-01

    Over the last thirty years, stress corrosion cracking in PWR primary water (PWSCC) has been observed in numerous Alloy 600 component items and associated welds, sometimes after relatively long incubation times. Repairs and replacements have generally utilized wrought Alloy 690 material and its compatible weld metals (Alloy 152 and Alloy 52), which have been shown to be very highly resistant to PWSCC in laboratory experiments and have been free from cracking in operating reactors over periods already up to nearly 15 years. It is nevertheless prudent for the PWR industry to attempt to quantify the longevity of these materials with respect to aging degradation by corrosion in order to provide a sound technical basis for the development of future inspection requirements for repaired or replaced component items. This document first reviews numerous laboratory tests, conducted over the last two decades, that were performed with wrought Alloy 690 and Alloy 52 or Alloy 152 weld materials under various test conditions pertinent to corrosion resistance in PWR environments. The main focus of the present review is on PWSCC, but secondary-side conditions are also briefly considered.

  2. Influence of Ga and Hg on microstructure and electrochemical corrosion behavior of Mg alloy anode materials

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of Hg and Ga on the electrochemical corrosion behavior of Mg-5%Hg (molar fraction) alloys were investigated by the measurement of polarization curves and galvanostatic test. The microstructure of the alloys and the corroded surface of the specimens were investigated by scanning electron microscopy, X-ray diffractometry and emission spectrum analysis. It can be concluded that the addition of 1%Ga (molar fraction) reduces corrosion current density from 26.98 mA/cm2 to 2.34 mA/cm2;while the addition of 1%Hg (molar fraction) increases corrosion current density. The addition of Ga and Hg both promotes the electrochemical activity of the alloys and the influence of Ga is more effective than Hg. Mg-5%Hg-1%Ga alloy has the best electrochemical activity, showing mean potential of-1.992 V. The activation mechanism of the magnesium alloy produced by Hg and Ga was put forward. Magnesium atoms are dissolved in liquid Hg and Ga to form amalgam and undergo severe oxidation at the amalgam/electrolyte interface.

  3. Process Simulation Role in the Development of New Alloys Based on Integrated Computational Material Science and Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Porter, Wallace D [ORNL; Roy, Shibayan [ORNL; Shyam, Amit [ORNL

    2014-01-01

    To accelerate the introduction of new materials and components, the development of metal casting processes requires the teaming between different disciplines, as multi-physical phenomena have to be considered simultaneously for the process design and optimization of mechanical properties. The required models for physical phenomena as well as their validation status for metal casting are reviewed. The data on materials properties, model validation, and relevant microstructure for materials properties are highlighted. One vehicle to accelerate the development of new materials is through combined experimental-computational efforts. Integrated computational/experimental practices are reviewed; strengths and weaknesses are identified with respect to metal casting processes. Specifically, the examples are given for the knowledge base established at Oak Ridge National Laboratory and computer models for predicting casting defects and microstructure distribution in aluminum alloy components.

  4. Imparting passivity to vapor deposited magnesium alloys

    Science.gov (United States)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  5. Buried waste containment system materials. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, J.R.; Shaw, P.G.

    1997-10-01

    This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers.

  6. Effect of substitutional element in the microstructure and hardness of Ti-Zr system alloys used as biomaterials; Efeito do elemento substitucional na microestrutura e dureza de ligas do sistema Ti-Zr para aplicacao como biomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Correa, D.R.N.; Vicente, F.B.; Grandini, C.R., E-mail: diegornc@fc.unesp.b [Universidade Estadual Paulista (UNESP), Bauru, SP (Brazil). Lab. de Anelasticidade e Biomateriais

    2010-07-01

    New titanium alloys had been developed with the aim of obtaining materials with improved properties for application as biomaterial, and alloys of the Ti-Zr system are among those most promising. The objective of this study is to analyze the influence of the zirconium concentration on microstructure and hardness of the Ti-5Zr, Ti-10Zr and Ti-15Zr alloys. After arc-melting melting, the samples were analyzed by chemical and gas composition, and characterized by density measurements, optical microscopy, x-ray diffraction and hardness. The results showed a microstructure formed by alpha phase (hexagonal close-packed structure) and increased of hardness. (author)

  7. Corrosion Testing of Ni Alloy HVOF Coatings in High Temperature Environments for Biomass Applications

    Science.gov (United States)

    Paul, S.; Harvey, M. D. F.

    2013-03-01

    This paper reports the corrosion behavior of Ni alloy coatings deposited by high velocity oxyfuel spraying, and representative boiler substrate alloys in simulated high temperature biomass combustion conditions. Four commercially available oxidation resistant Ni alloy coating materials were selected: NiCrBSiFe, alloy 718, alloy 625, and alloy C-276. These were sprayed onto P91 substrates using a JP5000 spray system. The corrosion performance of the coatings varied when tested at ~525, 625, and 725 °C in K2SO4-KCl mixture and gaseous HCl-H2O-O2 containing environments. Alloy 625, NiCrBSiFe, and alloy 718 coatings performed better than alloy C-276 coating at 725 °C, which had very little corrosion resistance resulting in degradation similar to uncoated P91. Alloy 625 coatings provided good protection from corrosion at 725 °C, with the performance being comparable to wrought alloy 625, with significantly less attack of the substrate than uncoated P91. Alloy 625 performs best of these coating materials, with an overall ranking at 725 °C as follows: alloy 625 > NiCrBSiFe > alloy 718 ≫ alloy C-276. Although alloy C-276 coatings performed poorly in the corrosion test environment at 725 °C, at lower temperatures (i.e., below the eutectic temperature of the salt mixture) it outperformed the other coating types studied.

  8. Magnetic and mechanical properties of deformable hard magnetic alloys on the Fe-Cr-Co system with 7% - 8% cobalt

    Institute of Scientific and Technical Information of China (English)

    Milyaev; A.; I.; Kovneristii; Ju.; K.; Yusupov; V.; S.; Korznikova; G.; F.

    2005-01-01

    With the purpose of the further increase of an economic efficiency hard magnetic alloys on the basis of system Fe-Cr-Co the study of magnetic and mechanical properties of alloys of this system in wt. % (26-30)Cr, (7-10)Co doped Ti, Si, V and Mo is carried out.……

  9. Application of Composite Materials in the Fire Explosion Suppression System

    Institute of Scientific and Technical Information of China (English)

    REN Shah

    2012-01-01

    In order to lighten the weight of the special vehicles and improve their mobility and flexibility, the weight of all subsystems of the whole vehicle must be reduced in the general planning. A fire explosion suppression system is an important subsystem for the self-protection of vehicle, protection of crews and safety of a vehicle. The performances of the special vehicles determine their survival ability and combat capability. The composite bottle is made of aluminum alloy with externally wrapped carbon fiber ; it has been proven by a large number of tests that the new type explosion suppression fire distinguisher made of such composite materials applied in the special vehicle has reliable performance, each of its technical indexes is higher or equal to that of a steel distinguisher, and the composites can also optimize the assembly structure of the bottle, and improve the reliability and corrosion resistance. Most important is that the composite materials can effectively lighten the weight of the fire explosion suppression system to reach the target of weight reduction of the subsystem in general planning.

  10. Producing Fe-W-Co-Cr-C Alloy Cutting Tool Material Through Powder Metallurgy Route

    Science.gov (United States)

    Datta Banik, Bibhas; Dutta, Debasish; Ray, Siddhartha

    2016-06-01

    High speed steel tools can withstand high impact forces as they are tough in nature. But they cannot retain their hardness at elevated temperature i.e. their hot hardness is low. Therefore permissible cutting speed is low and tools wear out easily. Use of lubricants is essential for HSS cutting tools. On the other hand cemented carbide tools can withstand greater compressive force, but due to lower toughness the tool can break easily. Moreover the cost of the tool is comparatively high. To achieve a better machining economy, Fe-W-Co-Cr-C alloys are being used nowadays. Their toughness is as good as HSS tools and hardness is very near to carbide tools. Even, at moderate cutting speeds they can be safely used in old machines having vibration. Moreover it is much cheaper than carbide tools. This paper highlights the Manufacturing Technology of the alloy and studies the comparative tribological properties of the alloy and tungsten mono carbide.

  11. Effect of Nickel Alloying Layer on Hydrogen Absorption Ability of Zr-Al Getter Material

    Institute of Scientific and Technical Information of China (English)

    LIU Chao-Zhuo; SHI Li-Qun

    2004-01-01

    @@ By using ion beam sputtering, an 85-A thick nickel layer was deposited on the Zr-Al alloy (non-evaporable getter) to improve the characteristic of the hydrogen absorption. The presputtering for 15 min to clean the surface passivation layer and the vacuum heating treatment of the sample at 750 ℃ for 1 h for surface alloying can improve the ability of the gas absorption. The gas absorption experiments show fast absorption kinetics of the hydrogen pumping and good durability against contaminable gases. The Rutherford-back-scattering spectra and the secondaryion mass spectroscopy demonstrate the formation of an alloy of Zr, Al, and Ni in the near-surface area after the thermal process. The elastic recoil detection analysis indicates that the sample holds the original high capacity of hydrogen.

  12. Fatigue-crack propagation in advanced aerospace materials: Aluminum-lithium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswara Rao, K.T.; Ritchie, R.O.

    1988-10-01

    Characteristics of fatigue-crack propagation behavior are reviewed for recently developed commercial aluminum-lithium alloys, with emphasis on the underlying micromechanisms associated with crack advance and their implications to damage-tolerant design. Specifically, crack-growth kinetics in Alcoa 2090-T8E41, Alcan 8090 and 8091, and Pechiney 2091 alloys, and in certain powder-metallurgy alloys, are examined as a function of microstructure, plate orientation, temperature, crack size, load ratio and loading sequence. In general, it is found that growth rates for long (> 10 mm) cracks are nearly 2--3 orders of magnitude slower than in traditional 2000 and 7000 series alloys at comparable stress-intensity levels. In additions, Al-Li alloys shown enhanced crack-growth retardations following the application of tensile overloads and retain superior fatigue properties even after prolonged exposure at overaging temperatures; however, they are less impressive in the presence of compression overloads and further show accelerated crack-growth behavior for microstructurally-small (2--1000 {mu}m) cracks (some three orders of magnitude faster than long cracks). These contrasting observations are attributed to a very prominent role of crack-tip shielding during fatigue-crack growth in Al-Li alloys, promoted largely by the tortuous and zig-zag nature of the crack-path morphologies. Such crack paths result in locally reduced crack-tip stress intensities, due to crack deflection and consequent crack wedging from fracture-surface asperities (roughness-induced crack closure); however, such mechanisms are far less potent in the presence of compressive loads, which act to crush the asperities, and for small cracks, where the limited crack wake severely restricts the shielding effect. 50 refs., 21 figs.

  13. Generic control of material handling systems

    NARCIS (Netherlands)

    Haneyah, S.W.A.

    2013-01-01

    Material handling systems (MHSs) are in general complex installations that raise challenging design and control problems. In the literature, design and control problems have received a lot of attention within distinct business sectors or systems, but primarily from a system’s user perspective. Much

  14. A survey on the effects of three surface treatment methods on bond strength between base-metal alloys and Ceromer material (Targis

    Directory of Open Access Journals (Sweden)

    Rokni. Sh.

    2004-08-01

    Full Text Available Statement of Problem: Ceramics and resins belong to the earliest tooth restorative materials. Nowadays new generations of these materials have provided a revolution in cosmetic dentistry. Ceramic Optimized polymer (Ceromer is a newly made product that the bond between this material and base metal alloys, which are used widely today, is paid too much attention. Purpose: The aim of this study was to evaluate the bond strength of targis (Ceromer to three types of base metal alloys through three different surface treatment methods. Materials and Methods: In this experimental study, ninety plates of Rexillium III, Silver cast and super cast alloys (3050.4 were prepared and surface treated through three different methods (air oxidation, vaccum oxidation and sandblast. All samples were then veneered with 1.mm thickness of Targis. After thermocycling, three-point bending test was performed by universal testing machine (Instron to evaluate the amount of forces at crack or fracture times in Targis. The type of failure (cohesive or adhesive was also evaluated microscopically. Statistical analyses were made using 2-factor ANOVA and Duncan tests. Results: The type of surface treatment method caused a statistically significant difference in force rate required for crack and fracture in Targis. Sandblasting was found as the best method. The type of alloys, in all three methods, had a significant effect just on crack creation attributing the largest amount of force to Rexillium III. Adhesive type of failure occurred mostly in super-cast alloys through air-oxidation method, and cohesive type was more among silver cast alloys and sandblast method. Conclusion: According to the results of this study, bond strength between Ceromer materials and base metal alloys is significantly great and Rexillium III alloy associated with sandblast technique the best combination.

  15. Climate control systems using pozzolan materials

    KAUST Repository

    Almadhoun, Mahmoud Nassar Mahmoud

    2016-02-18

    A system and method for conditioning air is provided that optimizes the use of sustainable and locally sourced materials with agrarian, residential, and industrial applications. The system can be formed with a porous siliceous, or siliceous and aluminous material that is sufficiently porous, to allow conditioning fluid to flow there through. The material can also be formed into a structure that includes one or more passageways configured to allow air to be conditioned to also pass there through. The structure can be configured to cause the conditioning fluid passing through the porous portions of the structure to intersect and mix with air passing there through. The structure may include a plurality of passageways and intersections and may include a plurality of air inlets and outlets for air passage. The system may additionally include a means for storing, collecting, and driving conditioning fluid through the system and a means for collecting solar radiation to drive airflow and regenerate conditioning fluid.

  16. Shape memory alloy heat engines and energy harvesting systems

    Science.gov (United States)

    Browne, Alan L; Johnson, Nancy L; Keefe, Andrew C; Alexander, Paul W; Sarosi, Peter Maxwell; Herrera, Guillermo A; Yates, James Ryan

    2013-12-17

    A heat engine includes a first rotatable pulley and a second rotatable pulled spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes first spring coil and a first fiber core within the first spring coil. A timing cable is disposed about disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

  17. Development of powder metallurgy 2XXX series Al alloy plate and sheet materials for high temperature aircraft structural applications, FY 1983/1984

    Science.gov (United States)

    Chellman, D. J.

    1985-01-01

    The objective of this investigation is to fabricate and evaluate PM 2124 Al alloy plate and sheet materials according to NASA program goals for damage tolerance and fatigue resistance. Previous research has indicated the outstanding strength-toughness relationship available with PM 2124 Al-Zr modified alloy compositions in extruded product forms. The range of processing conditions was explored in the fabrication of plate and sheet gage materials, as well as the resultant mechanical and metallurgical properties. The PM composition based on Al-3.70 Cu-1.85 Mg-0.20 Mn with 0.60 wt. pct. Zr was selected. Flat rolled material consisting of 0.250 in. thick plate was fabricated using selected thermal mechanical treatments (TMT). The schedule of TMT operations was designed to yield the extreme conditions of grain structure normally encountered in the fabrication of flat rolled products, specifically recrystallized and unrecrystallized. The PM Al alloy plate and sheet materials exhibited improved strength properties at thin gages compared to IM Al alloys, as a consequence of their enhanced ability to inhibit recrystallization and grain growth. In addition, the PM 2124 Al alloys offer much better combinations of strength and toughnessover equivalent IM Al. The alloy microstructures were examined by optical metallographic texture techniques in order to establish the metallurgical basis for these significant property improvements.

  18. Innovative reactor systems and requirements for structural materials

    International Nuclear Information System (INIS)

    The fast growing energy demand requires nuclear energy to play a role among other energy sources to satisfy future energy needs of mankind. Generation III light water reactors (LWRs) are anticipated to be built in large numbers to replace existing nuclear power plants or to augment the nuclear production capacity. Beyond the commercialization of best available light water reactor technologies, it is essential to start now the development of breakthrough technologies that will be needed to prepare the longer term future for nuclear power. These innovative systems include fast neutron reactors with a closed fuel cycle, high temperature reactors which could be used for process heat applications, accelerator driven systems or fusion reactors. Key technologies for such nuclear systems encompass high temperature structural materials, fast neutron resistant fuels and core materials, advanced fuel recycle processes with co-management of actinides, possibly including minor actinides, and specific reactor and power conversion technologies (intermediate heat-exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes...). The paper will give a brief overview of various materials that are essential for above nuclear systems' feasibility and performance, such as ferritic/martensitic steels (9-12% Cr), nickel-based alloys (Haynes 230, Inconel 617...), oxide dispersion strengthened -ferritic/martensitic steels, and ceramics. The paper will also give an insight into the various natures of R and D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, multi-scale modelling to predict macroscopic materials properties and to direct innovative research for improvements, lab-scale tests to characterise candidate materials mechanical properties and corrosion resistance, as well as component mock-up tests on technology loops to

  19. Novel Concepts for Damage-Resistant Alloys in Next Generation Nuclear Power Systems - Final Report , Project 99-0280

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, Stephen M.; Simonen, Edward P.; Gan, Jian; Garner, Francis A.; Gelles, David S.; Edwards, Danny J.; Andresen, Peter L.; Young, Lisa M.; Was, Gary S.; Fournier, L.; Sencer, Bulent H.

    2002-12-27

    The discovery of a damage-resistant alloy based on Hf solute additions to a low-carbon 316SS is the highlight of the Phase II research. This damage resistance is supported by characterization of radiation-induced microstructures and microchemistries along with measurements of environmental cracking. The addition of Hf to a low-carbon 316SS reduced the detrimental impact of radiation by changing the distribution of Hf. Pt additions reduced the impact of radiation on grain boundary segregation but did not alter its effect on microstructural damage development or cracking. Because cracking susceptibility is associated with several material characteristics, separate effect experiments exploring strength effects using non-irradiated stainless steels were conducted. These crack growth tests suggest that irradiation strength by itself can promote environmental cracking. The second concept for developing damage resistant alloys is the use of metastable precipitates to stabilize the microstructure during irradiation. Three alloys have been tailored for evaluation of precipitate stability influences on damage evolution. The first alloy is a Ni-base alloy (alloy 718) that has been characterized at low neutron irradiation doses but has not been characterized at high irradiation doses. The other two alloys are Fe-base alloys (PH 17-7 and PH 17-4) that have similar precipitate structures as alloy 718 but is more practical in nuclear structures because of the lower Ni content and hence lesser transmutation to He.

  20. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    International Nuclear Information System (INIS)

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with

  1. Systems based on hypo-eutectic Mg–Mg{sub 2}Ni alloys for medium to large scale hydrogen storage and delivery

    Energy Technology Data Exchange (ETDEWEB)

    Moroz, Stephanie, E-mail: stephanie.moroz@hydrexia.com; Tan, Xin Fu; Pierce, Jordan; Greaves, Matthew; Duguid, Andrew; Dumur, Krista; Ng, Jeffrey

    2013-12-15

    Highlights: •High performance, low cost hydrogen storage systems are in development based on a Mg–Mg2Ni alloy. •These systems have higher storage density than compressed gas •They can be filled with hydrogen at low pressure, removing the need for a compressor •The systems can deliver hydrogen at a lower cost per unit of hydrogen delivered than compressed gas. •The metal hydride systems also have significant safety advantages over compressed gas. -- Abstract: Magnesium based metal hydrides have a number of attractive properties for hydrogen storage, particularly the high storage density and the safety benefits of low pressure operation. A hypo-eutectic Mg–Mg{sub 2}Ni alloy has been developed. The material can be produced at a much lower cost than ball-milled materials while achieving a reversible storage of 6.5–7 wt% hydrogen at a rate of reaction that is acceptable for existing industrial applications. This alloy has been employed in a series of increasingly large prototype systems, reaching commercial scale in 2010 with a system storing 22 kg of hydrogen, appropriate for industrial merchant applications. The technology is also under development for larger scale applications such as refueling infrastructure and energy storage. This paper will discuss the potential applications of these systems and their technical and economic comparison to traditional compressed gas hydrogen storage and delivery.

  2. Materials Technology Support for Radioisotope Power Systems Final Report

    International Nuclear Information System (INIS)

    Over the period of this sponsored research, UDRI performed a number of materials related tasks that helped to facilitate increased understanding of the properties and applications of a number of candidate program related materials including; effects of neutron irradiation on tantalum alloys using a 500kW reactor, thermodynamic based modeling of the chemical species in weld pools, and the application of candidate coatings for increased oxidation resistance of FWPF (Fine Weave Pierced Fabric) modules

  3. Morphology of hydroxyapatite coated nanotube surface of Ti-35Nb-xHf alloys for implant materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Un [Functional Coatings Group, Materials Processing Division, Korea Institute of Materials Science (KIMS), Changwon, Kyungnam (Korea, Republic of); Jeong, Yong-Hoon [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave. Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of)

    2011-11-01

    The purpose of this research is to study the morphology of hydroxyapatite coated nanotube surface of Ti-35Nb-xHf for implant materials using various experiments. For this study, Ti-35Nb-xHf (x = 0, 3, 7 and 15 wt.%) alloys were prepared by arc melting and heat treated for 12 h at 1000 Degree-Sign C in an argon atmosphere and then water quenching. Nanotube formation on the Ti-35Nb-xHf alloys was achieved by anodizing in H{sub 3}PO{sub 4} electrolytes containing 0.8 wt.% NaF at room temperature. Anodization was carried out using an electrochemical method and all experiments were conducted at room temperature. Hydroxyapatite (HA) was deposited on the nanotubular Ti-35Nb-xHf alloys surface for the biomaterials by radio-frequency (RF) magnetron sputtering method. The morphologies of nanotubular and HA coated surface were characterized by X-ray diffractometer (XRD), optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM). The wettability of HA coated surface was measured by contact angle goniometer. The microstructure of Ti-35Nb-xHf alloys was transformed needle-like to equiaxed structure with Hf content and {alpha} Double-Prime phase decreased, whereas {beta} phase increased as Hf content increased. HA coating surface was affected by microstructure of bulk and morphology of nanotube formation. In case of low Hf content, tip of nanotube formed at {beta} phase was coated with HA film, whereas {alpha} Double-Prime phase was not coated with HA film. In case of high Hf content, nanotube surface was coated uniformly with HA film. The wettability of HA coated nanotubular surface was higher than that of non coated samples.

  4. Magnetic properties and domain structure of Fe-Al alloy as magnetostriction material

    Energy Technology Data Exchange (ETDEWEB)

    Gorlanova, M.A. E-mail: marina.gorlanova@usu.ru; Skulkina, N.A.; Kataev, V.A.; Ivanov, O.A.; Mikhaylov, A.A.; Kuranov, A.V

    2000-06-02

    The influence of the compressing electroinsulation coating, the annealing in magnetic field on the domain structure, magnetostriction and magnetic losses of Fe-Al alloy were investigated. The increase of magnetostriction, decrease of magnetic losses and appearance of residual magnetostriction with the formation of electroinsulation coating were observed. These unusual changes are connected with destabilization of domain boundaries.

  5. Oxygen for protective oxide scale formation on pins and structural material surfaces in lead-alloy cooled reactors

    International Nuclear Information System (INIS)

    Highlights: • Pb alloy coolants require oxygen for in situ oxide scale formation. • Initial scale growth requires large amounts of oxygen. • Pre-oxidation is needed to assure oxygen delivery. • Surface aluminization slows down oxygen consumption by half. • PbO based oxygen transfer needed for phases of high consumption. - Abstract: Oxygen dissolved in liquid Pb alloys prevents dissolution attack on structural steels by formation of oxide scales on the surface. The required amount of oxygen for continuous scale formation depends on temperature on the kind of steel and its oxidation behavior. Compatibility of the steels in reactor systems with liquid lead alloys can only be maintained if the oxygen consumed by the growing oxide scales is replaced. Calculation of the oxygen consumed is performed on the basis of experiments on the oxide scale growth on steels in liquid Pb alloys. These calculations consider also the change in surface temperature caused by the growth of the oxide scales. The design data of EFIT (European Facility for Industrial Transmutation) and a realistic start-up scenario for such a system was used in the investigation. Also the impact of fuel element exchange and the replacement of heat exchangers were considered. The oxygen consumption is very high in the beginning, when the metals get into contact with the lead alloy. It is a great advantage to employ structures that have already protective oxide scales or can form those during a commissioning phase at 400 °C inside the reactor. Otherwise, the oxygen consumption rate would be difficult to handle. A further great improvement would be to alloy the surface of heavy loaded structure parts like the high temperature parts of fuel pins and the heat exchanger tubes with Al to form thin stable oxide films, which, furthermore, have the advantage of a low thermal resistance. This surface treatment would cut down the overall oxygen consumption to less than the half of it. It may be not possible to

  6. Oxygen for protective oxide scale formation on pins and structural material surfaces in lead-alloy cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Weisenburger, Alfons, E-mail: alfons.weisenburger@kit.edu [Institute for Pulsed Power and Microwave Technology (IHM), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Mansani, Luigi [ANSALDO NUCLEARE S.p.a., C.so F.M. Perrone 25, 16152 Genova (Italy); Schumacher, Gustav; Müller, Georg [Institute for Pulsed Power and Microwave Technology (IHM), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-07-01

    Highlights: • Pb alloy coolants require oxygen for in situ oxide scale formation. • Initial scale growth requires large amounts of oxygen. • Pre-oxidation is needed to assure oxygen delivery. • Surface aluminization slows down oxygen consumption by half. • PbO based oxygen transfer needed for phases of high consumption. - Abstract: Oxygen dissolved in liquid Pb alloys prevents dissolution attack on structural steels by formation of oxide scales on the surface. The required amount of oxygen for continuous scale formation depends on temperature on the kind of steel and its oxidation behavior. Compatibility of the steels in reactor systems with liquid lead alloys can only be maintained if the oxygen consumed by the growing oxide scales is replaced. Calculation of the oxygen consumed is performed on the basis of experiments on the oxide scale growth on steels in liquid Pb alloys. These calculations consider also the change in surface temperature caused by the growth of the oxide scales. The design data of EFIT (European Facility for Industrial Transmutation) and a realistic start-up scenario for such a system was used in the investigation. Also the impact of fuel element exchange and the replacement of heat exchangers were considered. The oxygen consumption is very high in the beginning, when the metals get into contact with the lead alloy. It is a great advantage to employ structures that have already protective oxide scales or can form those during a commissioning phase at 400 °C inside the reactor. Otherwise, the oxygen consumption rate would be difficult to handle. A further great improvement would be to alloy the surface of heavy loaded structure parts like the high temperature parts of fuel pins and the heat exchanger tubes with Al to form thin stable oxide films, which, furthermore, have the advantage of a low thermal resistance. This surface treatment would cut down the overall oxygen consumption to less than the half of it. It may be not possible to

  7. Development of a magnesium secondary alloy system for mixed magnesium post-consumer scrap

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, Daniel, E-mail: dfechner@tuev-nord.de; Blawert, Carsten; Hort, Norbert; Dieringa, Hajo; Kainer, Karl Ulrich

    2013-08-01

    Six alloys were prepared by high pressure die casting in order to develop a magnesium secondary alloy system for mixed post-consumer scrap. The alloys were investigated with regard to intermetallic phases, grain structures, mechanical properties and performance in the salt spray test. The results are discussed in relation to the characteristics of the high pressure die casting process. The effect of contamination by copper and compensation for this effect by the addition of zinc were thoroughly investigated for the most promising alloy. It is evident that the alloying elements strontium, silicon and calcium are incorporated in the ternary Zintl phase Sr{sub 6.33}Mg{sub 16.67}Si{sub 13}, while aluminium, zinc, copper and magnesium form the tau-phases Mg{sub 32}(Al{sub x},Cu{sub 1−x}){sub 49} and Mg{sub 32}(Al,Zn){sub 49}. The two tau-phases can merge due to isomorphism. Mg{sub 32}(Al,Zn){sub 49} ensures improved corrosion resistance after the addition of copper.

  8. Properties and response of composite material with spheroidal superelastic shape memory alloy inclusions subject to three-dimensional stress state

    International Nuclear Information System (INIS)

    This communication illustrates the method of evaluation of the stiffness tensor and the stress-strain relationship of a particulate composite material with randomly distributed spheroidal superelastic shape memory alloy (SMA) inclusions that is subject to three-dimensional stresses. The Mori-Tanaka homogenization technique in conjunction with the Tanaka phenomenological SMA theory is applied to develop relations between the properties of the composite material and the applied stresses. In addition, the composite stress-strain loop reflecting hysteresis within the SMA material is generated. It is shown that the energy dissipation within a metal matrix composite with spherical SMA inclusions is comparable to that observed in composites with SMA fibres. The solution is exact within the framework of the assumptions of the Mori-Tanaka and phenomenological SMA theories.

  9. Mechanical alloying in Fe2O3-MO (M: Zn, Ni, Cu, Mg) systems

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Gerward, Leif; Mørup, Steen

    1999-01-01

    Mechanical alloying processes in four Fe2O3MO (M: Zn, Ni, Cu, Mg) systems by high-energy ball milling from simple oxide powder mixtures in both open and closed tungsten carbide containers have been investigated by x-ray powder diffraction and Mossbauer spectroscopy. Mechanisms for the formation o...

  10. Nonlinear dynamics of a pseudoelastic shape memory alloy system - theory and experiment

    DEFF Research Database (Denmark)

    Enemark, Søren; A Savi, M.; Santos, Ilmar

    2014-01-01

    capabilities and varying stiffness. Besides, these properties depend on the temperature and pretension conditions. Because of these capabilities, shape memory alloys are interesting in relation to engineering design of dynamic systems. A theoretical model based on a modification of the 1D Brinson model...

  11. Physicochemical properties of alloys of PbTe-Fe2Te3 system

    International Nuclear Information System (INIS)

    Physicochemical and some electric properties of PbTe-Fe2Te3 cut alloys are investigated. State diagram for this system where at 1145 K PbFe2Te4 new ternary compound is formed, is plotted. Temperature dependences of electric parameters have shown that PbFe2Te4 compound is semiconductor with conductivity of electron type

  12. Enhancement and Commercialization of the Alloy Selection System for Elevated Temperatures - ASSET

    Energy Technology Data Exchange (ETDEWEB)

    Randy C. John

    2005-11-05

    A corrosion engineering information system was created to manage, correlate and predict corrosion of alloys and also to use thermochemical calculations to predict the occurrence of dominant corrosion mechanisms in hot gases found in many different chemical processes and other related industrial processes.

  13. Formation of hydrotalcite coating on the aluminum alloy 6060 in spray system

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie;

    2016-01-01

    Coatings with the composition of Li-Al-NO3 hydrotalcite were formed on the Al alloy 6060 using a spray system. The coatings consist of crystals with a typical hydrotalcite structure. Dense, uniform and blade-like flakes cover completely the surface of the Al substrate. The coatings display a mult...

  14. Molecular level assessment of thermal transport and thermoelectricity in materials: From bulk alloys to nanostructures

    Science.gov (United States)

    Kinaci, Alper

    The ability to manipulate material response to dynamical processes depends on the extent of understanding of transport properties and their variation with chemical and structural features in materials. In this perspective, current work focuses on the thermal and electronic transport behavior of technologically important bulk and nanomaterials. Strontium titanate is a potential thermoelectric material due to its large Seebeck coefficient. Here, first principles electronic band structure and Boltzmann transport calculations are employed in studying the thermoelectric properties of this material in doped and deformed states. The calculations verified that excessive carrier concentrations are needed for this material to be used in thermoelectric applications. Carbon- and boron nitride-based nanomaterials also offer new opportunities in many applications from thermoelectrics to fast heat removers. For these materials, molecular dynamics calculations are used to evaluate lattice thermal transport. To do this, first, an energy moment term is reformulated for periodic boundary conditions and tested to calculate thermal conductivity from Einstein relation in various systems. The influences of the structural details (size, dimensionality) and defects (vacancies, Stone-Wales defects, edge roughness, isotopic disorder) on the thermal conductivity of C and BN nanostructures are explored. It is observed that single vacancies scatter phonons stronger than other type of defects due to unsatisfied bonds in their structure. In pristine states, BN nanostructures have 4-6 times lower thermal conductivity compared to C counterparts. The reason of this observation is investigated on the basis of phonon group velocities, life times and heat capacities. The calculations show that both phonon group velocities and life times are smaller in BN systems. Quantum corrections are also discussed for these classical simulations. The chemical and structural diversity that could be attained by

  15. [A medical consumable material management information system].

    Science.gov (United States)

    Tang, Guoping; Hu, Liang

    2014-05-01

    Medical consumables material is essential supplies to carry out medical work, which has a wide range of varieties and a large amount of usage. How to manage it feasibly and efficiently that has been a topic of concern to everyone. This article discussed about how to design a medical consumable material management information system that has a set of standardized processes, bring together medical supplies administrator, suppliers and clinical departments. Advanced management mode, enterprise resource planning (ERP) applied to the whole system design process. PMID:25241525

  16. Effect of cobalt content on electrochemical performance of La-Mg-Ni system (Ce2Ni7-type) electrode alloys

    Institute of Scientific and Technical Information of China (English)

    WANG Xinlin; DONG Xiaoping; ZHANG Yanghuan; GUO Shihai; Lü Fanxiu

    2008-01-01

    In order to improve the cyclic stability of La-Mg-Ni system (Ce2Ni7-type) alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure of the alloys were investigated in detail. XRD results showed that the alloys had multiphase structure composed of (La, Mg)2Ni7, LaNi5 and small amount of LaNi2 phases. The discharge capacity of the alloys first increased and then decreased with increasing Co content. At a discharge current density of 900 mA/g, the HRD of the alloy electrodes increased from 81.3% (x=0) to 89.2 % (x=0.2), and then reduced to 87.8 % (x=0.6). After 60 charge/discharge cycles, the capacity retention rate of the alloys enhanced from 52.67% to 61.32%, and the capacity decay rate of the alloys decreased from 2.60 to 2.05 mAh/g per cycle with increasing Co content. The obtained results by XPS and XRD showed that the fundamental reasons for the capacity decay of the La-Mg-Ni system (Ce2Ni7-type) alloy electrodes were corrosion and oxidation as well as passivation of Mg and La in alkaline solution.

  17. Thermodynamic analysis of the change of solid solubility in a binary system processed by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, C. [Instituto de Materiales y Procesos Termomecanicos, Facultad de Ciencias de la Ingenieria, Universidad Austral de Chile, Av. General Lagos 2086, Valdivia (Chile)], E-mail: ceaguilar@uach.cl; Martinez, V. [TEKMETALL, Metallurgical Solutions S.L., Po de Manuel Lardizabal No17, 20018 Donostia-Gipuzkoa (Spain); Navea, L.; Pavez, O.; Santander, M. [Departamento de Metalurgia, Facultad de Ingenieria, Universidad de Atacama, Av. Copayapu 485, Copiapo (Chile)

    2009-03-05

    Using a non-equilibrium process, it is possible to extend the solid solubility range in metallic systems. Therefore, the main objective of this work was to apply a thermodynamic model to predict the change in the solubility limit of systems with positive enthalpy mixing (Cu-Cr and Fe-Cu) processed by mechanical alloying. It was found that increasing the density of crystalline defects alters the solubility limit in these binary systems.

  18. Integration of Shape Memory Alloys into Low-Damped Rotor-Bearing Systems

    DEFF Research Database (Denmark)

    Enemark, Søren

    2015-01-01

    to use passive adaptive control through smart materials. Shape Memory Alloys (SMAs) are interesting candidates in that relation, because of their highly temperature sensitive stiffness and mechanical hysteresis, which can be used for damping purposes. The thesis focuses on three main aspects related...... properties. Different element geometries are investigated with focus on helical springs. Several spring models are presented, which use different levels of approximations to the mechanical stress state. The models are compared to experimental results covering different levels of temperature, deformation...

  19. Shape memory alloy heat engines and energy harvesting systems

    Energy Technology Data Exchange (ETDEWEB)

    Browne, Alan L; Johnson, Nancy L; Shaw, John Andrew; Churchill, Christopher Burton; Keefe, Andrew C; McKnight, Geoffrey P; Alexander, Paul W; Herrera, Guillermo A; Yates, James Ryan; Brown, Jeffrey W

    2014-09-30

    A heat engine includes a first rotatable pulley and a second rotatable pulley spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes a first wire, a second wire, and a matrix joining the first wire and the second wire. The first wire and the second wire are in contact with the pulleys, but the matrix is not in contact with the pulleys. A timing cable is disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

  20. Application of advanced austenitic alloys to fossil power system components

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W.

    1996-06-01

    Most power and recovery boilers operating in the US produce steam at temperatures below 565{degrees}C (1050{degrees}F) and pressures below 24 MPa (3500 psi). For these operating conditions, carbon steels and low alloy steels may be used for the construction of most of the boiler components. Austenitic stainless steels often are used for superheater/reheater tubing when these components are expected to experience temperatures above 565{degrees}C (1050{degrees}F) or when the environment is too corrosive for low alloys steels. The austenitic stainless steels typically used are the 304H, 321H, and 347H grades. New ferritic steels such as T91 and T92 are now being introduced to replace austenitic: stainless steels in aging fossil power plants. Generally, these high-strength ferritic steels are more expensive to fabricate than austenitic stainless steels because the ferritic steels have more stringent heat treating requirements. Now, annealing requirements are being considered for the stabilized grades of austenitic stainless steels when they receive more than 5% cold work, and these requirements would increase significantly the cost of fabrication of boiler components where bending strains often exceed 15%. It has been shown, however, that advanced stainless steels developed at ORNL greatly benefit from cold work, and these steels could provide an alternative to either conventional stainless steels or high-strength ferritic steels. The purpose of the activities reported here is to examine the potential of advanced stainless steels for construction of tubular components in power boilers. The work is being carried out with collaboration of a commercial boiler manufacturer.

  1. Development of a rotor alloy for advanced ultra super critical turbine power generation system

    Energy Technology Data Exchange (ETDEWEB)

    Miyashita, Shigekazu; Yamada, Masayuki; Suga, Takeo; Imai, Kiyoshi; Nemoto, Kuniyoshi; Yoshioka, Youmei [Toshiba Corporation, Yokohama (Japan)

    2008-07-01

    A Ni-based superalloy ''TOS1X'', for the rotor material of the 700 class advanced ultra super critical (A-USC) turbine power generation system was developed. TOS1X is an alloy that is improved in the creep rupture strength of Inconel trademark 617 maintaining both forgeability and weldability. The 7 t weight model rotor made of TOS1X was manufactured by double melt process, vacuum induction melting and electro slag remelting, and forging. During forging process, forging cracks and any other abnormalities were not detected on the ingots. The metallurgical and the mechanical properties in this rotor were investigated. Macro and micro structure observation, and some mechanical tests were conducted. According to the metallurgical structure investigation, there was no remarkable segregation in whole area and the forging effect was reached in the center part of the rotor ingot. The results of tensile test and creep rupture test proved that proof stress and tensile stress of the TOS1X are higher than those of Inconel trademark 617 and creep rupture strength of TOS1X is much superior than that of Inconel trademark 617. (orig.)

  2. Generic control of material handling systems

    OpenAIRE

    Haneyah, S.W.A.

    2013-01-01

    Material handling systems (MHSs) are in general complex installations that raise challenging design and control problems. In the literature, design and control problems have received a lot of attention within distinct business sectors or systems, but primarily from a system’s user perspective. Much less attention is paid to generic (i.e., sector independent) control architectures and modeling approaches across these various sectors, which is in the first place interesting for MHS suppliers. I...

  3. Performance of tantalum-tungsten alloy selective emitters in thermophotovoltaic systems

    Science.gov (United States)

    Stelmakh, Veronika; Rinnerbauer, Veronika; Chan, Walker R.; Senkevich, Jay J.; Joannopoulos, John D.; Soljačić, Marin; Celanovic, Ivan

    2014-06-01

    A tantalum tungsten solid solution alloy, Ta 3% W, based 2D photonic crystal (PhC) was designed and fabricated for high-temperature energy conversion applications. Ta 3% W presents advantages compared to the non-alloys as it combines the better high-temperature thermomechanical properties of W with the more compliant material properties of Ta, allowing for a direct system integration path of the PhC as selective emitter/absorber into a spectrum of energy conversion systems. Indeed metallic PhCs are promising as high performance selective thermal emitters for thermophotovoltaics (TPV), solar thermal, and solar TPV applications due to the ability to tune their spectral properties and achieve highly selective emission. A 2D PhC was designed to have high spectral selectivity matched to the bandgap of a TPV cell using numerical simulations and fabricated using standard semiconductor processes. The emittance of the Ta 3% WPhC was obtained from near-normal reectance measurements at room temperature before and after annealing at 1200 °C for 24h in vacuum with a protective coating of 40 nm HfO2, showing high selectivity in agreement with simulations. SEM images of the cross section of the PhC prepared by FIB confirm the structural stability of the PhC after anneal, i.e. the coating effectively prevented structural degradation due to surface diffusion. The mechanical and thermal stability of the substrate was characterized as well as the optical properties of the fabricated PhC. To evaluate the performance of the selective emitters, the spectral selectivity and useful emitted power density are calculated as a function of operating temperature. At 1200 °C, the useful emitted irradiance is selectively increased by a factor of 3 using the selective emitter as compared to the non-structured surface. All in all, this paper demonstrates the suitability of 2D PhCs fabricated on polycrystalline Ta-W substrates with an HfO2 coating for TPV applications.

  4. SYSTEM ORGANIZATION OF MATERIAL PROVIDING OF BUILDING

    Directory of Open Access Journals (Sweden)

    A. V. Rаdkеvich

    2014-04-01

    Full Text Available Purpose. Development of scientific-methodical bases to the design of rational management of material streams in the field of building providing taking into account intersystem connections with the enterprises of building industry. Methodology. The analysis of last few years of functioning of building industry in Ukraine allows distinguishing a number of problems that negatively influence the steady development of building, as the component of the state economics system. Therefore the research of existent organization methods of the system of building objects providing with material resources is extremely necessary. In connection with this the article justifies the use of method of hierarchies analysis (Saati method for finding the optimal task solution of fixing the enterprises of building industry after building objects. Findings. Results give an opportunity to guidance of building organization to estimate and choose advantageous suppliers - enterprises of building industry, to conduct their rating, estimation taking into account basic descriptions, such as: quality, price, reliability of deliveries, specialization, financial status etc. Originality. On the basis of Saati method the methodologies of organization are improved, planning and managements of the reliable system of providing of building necessary material resources that meet the technological requirements of implementation of building and installation works. Practical value. Contribution to the decisions of many intricate organizational problems that are accompanied by the problems of development of building, provided due to organization of the reliable system of purchase of material resources.

  5. Design of POLCA material control systems

    NARCIS (Netherlands)

    Riezebos, J.

    2010-01-01

    POLCA is a material control system designed for make-to-order or engineer-to-order companies. These firms have to cope with a high variety of customised products, and strong pressure to provide short throughput times. POLCA constrains the amount of work in progress on the shop floor in order to achi

  6. Hydrogen embrittlement and hydrogen induced stress corrosion cracking of high alloyed austenitic materials; Wasserstoffversproedung und wasserstoffinduzierte Spannungsrisskorrosion hochlegierter austenitischer Werkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Mummert, K.; Uhlemann, M.; Engelmann, H.J. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany)

    1998-11-01

    The susceptiblity of high alloyed austenitic steels and nickel base alloys to hydrogen-induced cracking is particularly determined by 1. the distribution of hydrogen in the material, and 2. the microstructural deformation behaviour, which last process is determined by the effects of hydrogen with respect to the formation of dislocations and the stacking fault energy. The hydrogen has an influence on the process of slip localization in slip bands, which in turn affects the microstructural deformation behaviour. Slip localization increases with growing Ni contents of the alloys and clearly reduces the ductility of the Ni-base alloy. Although there is a local hydrogen source involved in stress corrosion cracking, emanating from the corrosion process at the cathode, crack growth is observed only in those cases when the hydrogen concentration in a small zone ahead of the crack tip reaches a critical value with respect to the stress conditions. Probability of onset of this process gets lower with growing Ni content of the alloy, due to increasing diffusion velocity of the hydrogen in the austenitic lattice. This is why particularly austenitic steels with low Ni contents are susceptible to transcrystalline stress corrosion cracking. In this case, the microstructural deformation process at the crack tip is also influenced by analogous processes, as could be observed in hydrogen-loaded specimens. (orig./CB) [Deutsch] Die Empfindlichkeit von hochlegierten austentischen Staehlen und Nickelbasislegierungen gegen wasserstoffinduziertes Risswachstum wird im wesentlichen bestimmt durch 1. die Verteilung von Wasserstoff im Werkstoff und 2. das mikrostrukturelle Verformungsverhalten. Das mikrostrukturelle Deformationsverhalten ist wiederum durch den Einfluss von Wasserstoff auf die Versetzungsbildung und die Stapelfehlerenergie charakterisiert. Das mikrostrukturelle Verformungsverhalten wird durch wasserstoffbeeinflusste Gleitlokalisierung in Gleitbaendern bestimmt. Diese nimmt mit

  7. Titanium alloys as fixation device material for cranioplasty and its safety in electroconvulsive therapy.

    Science.gov (United States)

    Kaido, Takanobu; Noda, Takamasa; Otsuki, Taisuke; Kaneko, Yuu; Takahashi, Akio; Nakai, Tetsuji; Nabatame, Maki; Tani, Mariko

    2011-03-01

    Here, we report the case of a patient successfully treated by a series of electroconvulsive therapy (ECT) who had implanted skull fixation devices made of titanium alloy. The patient was a 57-year-old man with bipolar I disorder. He was hospitalized for the treatment of manic symptoms of bipolar I disorder with pharmacotherapy and ECT. He sustained a fall and hit his head hard on the ground. Acute subdural hematoma developed, and emergent surgery to remove the hematoma was carried out. Cranioplasty was performed using fixation devices made of titanium alloy (Ti 6Al-4V). In order to control his manic symptoms, a series of ECT was readministered from 1 week after surgery. No adverse effects occurred. Devices must be investigated and chosen very carefully for permanent implantation, especially in patients during a course of ECT.

  8. Aluminum-Scandium Alloys: Material Characterization, Friction Stir Welding, and Compatibility With Hydrogen Peroxide (MSFC Center Director's Discretionary Fund Final Report, Proj. No. 04-14)

    Science.gov (United States)

    Lee, J. A.; Chen, P. S.

    2004-01-01

    This Technical Memorandum describes the development of several high-strength aluminum (Al) alloys that are compatible with hydrogen peroxide (H2O2) propellant for NASA Hypersonic-X (Hyper-X) vehicles fuel tanks and structures. The yield strengths for some of these Al-magnesium-based alloys are more than 3 times stronger than the conventional 5254-H112 Al alloy, while maintaining excellent H2O2 compatibility similar to class 1 5254 alloy. The alloy development strategy is to add scandium, zirconium, and other transitional metals with unique electrochemical properties, which will not act as catalysts, to decompose the highly concentrated 90 percent H2O2. Test coupons are machined from sheet metals for H2O2 long-term exposure testing and mechanical properties testing. In addition, the ability to weld the new alloys using friction stir welding has also been explored. The new high-strength alloys could represent an enabling material technology for Hyper-X vehicles, where flight weight reduction is a critical requirement.

  9. An investigation on corrosion protection of chromium nitride coated Fe-Cr alloy as a bipolar plate material for proton exchange membrane fuel cells

    Science.gov (United States)

    Pan, T. J.; Zhang, B.; Li, J.; He, Y. X.; Lin, F.

    2014-12-01

    The corrosion properties of chromium nitride (CrN) coating are investigated to assess the potential use of this material as a bipolar plate for proton exchange membrane fuel cells (PEMFCs). Conductive metallic ceramic CrN layers are firstly deposited onto Fe-Cr alloy using a multi-arc ion plating technique to increase the corrosion resistance of the base alloy. Electrochemical measurements indicate that the corrosion resistance of the substrate alloy is greatly enhanced by the CrN coating. The free corrosion potential of the substrate is increased by more than 50 mV. Furthermore, a decrease in three orders of magnitude of corrosive current density for the CrN-coated alloy is observed compared to the as-received Fe-Cr alloy. Long-term immersion tests show that the CrN layer is highly stable and effectively acts as a barrier to inhibit permeation of corrosive species. On the contrary, corrosion of the Fe-Cr alloy is rather severe without the protection of CrN coating due to the active dissolution. Finally, the corresponding electrochemical impedance models are proposed to elucidate the corrosion process of the CrN/Fe-Cr alloy submerged in a simulated PEMFCs environment.

  10. Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

    Science.gov (United States)

    Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

    2010-01-01

    The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

  11. Influence of cooling rates on properties of pre-alloyed PM materials

    OpenAIRE

    L.A. Dobrzański; M. Musztyfaga

    2009-01-01

    Purpose: The paper focuses on microstructural and mechanical properties of pre-alloyed Astaloy CrL and CrM sintered steels with high addition of carbon.Design/methodology/approach: The main objective of the present work was to establish the effect of cooling rates on the microstructure and properties such as: Charpy impact test, microhardness, wear resistance (disk on disk test) were evaluated depending on chemical composition. Compacts containing low amounts of chromium, molybdenum and high ...

  12. An Assessment of the Mechanical Properties and Microstructural Analysis of Dissimilar Material Welded Joint between Alloy 617 and 12Cr Steel

    Directory of Open Access Journals (Sweden)

    Hafiz Waqar Ahmad

    2016-10-01

    Full Text Available The most effective method to reduce CO2 gas emission from the steam power plant is to improve its performance by elevating the steam temperature to more than 700 °C. For this, it is necessary to develop applicable materials at high temperatures. Ni-based Alloy 617 and 12Cr steel are used in steam power plants, due to their remarkable mechanical properties, high corrosion resistance, and creep strength. However, since Alloy 617 and 12Cr steel have different chemical compositions and thermal and mechanical properties, it is necessary to develop dissimilar material welding technologies. Moreover, in order to guarantee the reliability of dissimilar material welded structures, the assessment of mechanical and metallurgical properties, fatigue strength, fracture mechanical analysis, and welding residual stress analysis should be conducted on dissimilar material welded joints. In this study, first, multi-pass dissimilar material welding between Alloy 617 and 12Cr steel was performed under optimum welding conditions. Next, mechanical properties were assessed, including the static tensile strength, hardness distribution, and microstructural analysis of a dissimilar material welded joint. The results indicated that the yield strength and tensile strength of the dissimilar metal welded joint were higher than those of the Alloy 617 base metal, and lower than those of the 12Cr steel base metal. The hardness distribution of the 12Cr steel side was higher than that of Alloy 617 and the dissimilar material weld metal zone. It was observed that the microstructure of Alloy 617 HAZ was irregular austenite grain, while that of 12Cr steel HAZ was collapsed martensite grain, due to repeatable heat input during multi-pass welding.

  13. Laser/EMAT measurement systems for materials evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Dewhurst, R J; Dutton, B [Centre for Instrumentation and Analytical Science, School of Chemical Engineering and Analytical Science, Faraday Building, University of Manchester, PO Box 88, Manchester, M60 1QD (United Kingdom)

    2007-07-15

    This paper describes two applications of laser/ electromagnetic acoustic transducer (EMAT) systems. The first application uses laser-generated ultrasound for the characterisation of rear surface artificial defects (vertical slots) in metal samples. An EMAT sensitive to in-plane motion was used to detect these ultrasonic waves. B-scan images were used to visualise any changes of interrogating waves due to defects. These images were generated as the sensor head was moved along the material's surface, forming a 2D intensity profile that revealed changes in the presence of a defect. The defects produced distinctive parabolic features in the images from the time-of-flight diffraction by shear waves. The paper presents a new method based on a generalized Radon transform (GRT) to automatically determine the depth and location of back-surface artificial defects from B-scan images. Experimental evidence validated predicted results for the case of 1.5-3.5 mm-deep defects. The second application uses Rayleigh waves to quantify inhomogeneities in metal alloys using a transient Rayleigh pulse detected with an eight-element EMAT-array. The array spacing established sensor separation, so that velocity measurements were performed independent of the source-to-detector separation. Eliminating this distance, which would normally lead to systematic errors, has produced a measurement system capable of measuring velocities in metal with a precision of 99.9 %. As an example, variations in the Rayleigh wave velocity have characterised the inhomogeneities in rolled bars of aluminium.

  14. Basic research for alloy design of Nb-base alloys as ultra high temperature structural materials; Chokoon kozoyo niobuki gokin no gokin sekkei no tame no kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Miura, E. [Tohoku University, Sendai (Japan); Yoshimi, K.; Hanada, S. [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

    1997-02-01

    This paper describes an influence of additional elements on the high temperature deformation behavior of Nb-base solid solution alloys. Highly concentrated solid solution single crystals of Nb-Ta and Nb-Mo alloys were prepared. Compression test and strain rate sudden change test were conducted in the vacuum at temperatures ranging from 77 to 1773 K, to determine the strain rate sensitivity index. Yield stress of the Nb-Ta alloy was similar to that of Nb alloy at temperatures over 0.3{times}T{sub M}, where T{sub M} is fusing point of Nb. While, the yield stress increased with increasing the impurity oxygen concentration at temperatures below 0.3{times}T{sub M}. The yield stress became much higher than that of Nb alloy. The strain rate sensitivity index showed positive values in the whole temperature range. On the other hand, the yield stress of Nb-Mo alloy was higher than that of Nb alloy in the whole temperature range, and increased with increasing the Mo concentration. The strain rate sensitivity index showed negative values at the temperature range from 0.3{times}T{sub M} to 0.4{times}T{sub M}. It was found that serration occurred often for Nb-40Mo alloys. 1 ref., 4 figs., 1 tab.

  15. NASA-UVA Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft. Final report, 1 December 1991-31 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Starke, E.A. Jr.

    1996-05-01

    This is the final report of the study `Aluminum-Based Materials for high Speed Aircraft` which had the objectives (1) to identify the most promising aluminum-based materials with respect to major structural use on the HSCT and to further develop those materials and (2) to assess the materials through detailed trade and evaluation studies with respect to their structural efficiency on the HSCT. The research team consisted of ALCOA, Allied-Signal, Boeing, McDonnell Douglas, Reynolds Metals and the University of Virginia. Four classes of aluminum alloys were investigated: (1) I/M 2XXX containing Li and I/M 2XXX with Li, (2) I/M 6XXX, (3) two P/M 2XXX alloys and (4) two different aluminum-based metal matrix composites (MMC). The I/M alloys were targeted for a Mach 2.0 aircraft and the P/M and MMC alloys were targeted for a Mach 2.4 aircraft. Design studies were conducted using several different concepts including skin/stiffener (baseline), honeycomb sandwich, integrally stiffened and hybrid adaptations (conventionally stiffened thin-sandwich skins). Alloy development included fundamental studies of coarsening behavior, the effect of stress on nucleation and growth of precipitates, and fracture toughness as a function of temperature were an integral part of this program. The details of all phases of the research are described in this final report.

  16. Rapid Prototyping for In Vitro Knee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

    Directory of Open Access Journals (Sweden)

    Christian Schröder

    2015-01-01

    Full Text Available Retropatellar complications after total knee arthroplasty (TKA such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics.

  17. Laser Weldability of High-Strength Al-Zn Alloys and Its Improvement by the Use of an Appropriate Filler Material

    Science.gov (United States)

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

    2016-06-01

    Heat-treatable Al-Zn alloys are promising candidates for use as structural lightweight materials in automotive and aircraft applications. This is mainly due to their high strength-to-density ratio in comparison to conventionally employed Al alloys. Laser beam welding is an efficient method for producing joints with high weld quality and has been established in the industry for many years. However, it is well known that aluminum alloys with a high Zn content or, more precisely, with a high (Zn + Mg + Cu) content are difficult to fusion weld due to the formation of porosity and hot cracks. The present study concerns the laser weldability of these hard-to-weld Al-Zn alloys. In order to improve weldability, it was first necessary to understand the reasons for weldability problems and to identify crucial influencing factors. Based on this knowledge, it was finally possible to develop an appropriate approach. For this purpose, vanadium was selected as additional filler material. Vanadium exhibits favorable thermophysical properties and, thereby, can improve the weldability of Al-Zn alloys. The effectiveness of the approach was verified by its application to several Al-Zn alloys with differing amounts of (Zn + Mg + Cu).

  18. Effect of welding speed on the material flow patterns in friction stir welding of AZ31 magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua; Wu Huiqiang; Huang Jihua; LIN Sanbao; WU Lin

    2007-01-01

    The clear zigzag-line pattern on transverse cross sections can be used to explain the formation mechanism of the weld nugget when friction stir welded AZ31 magnesium alloy without any other insert material is used as mark. It provides a simple and useful method to research the joining mechanism of friction stir welding. The rotation speed is kept at 1000 r/min and the welding speed changes from 120 mm/min to 600 mm/min. The macrostructure on the transverse cross section was divided into several parts by faying surface. The results show that the shape and formation procedure of the weld nugget change with the welding speed. There are two main material flows in the weld nugget: one is from the advancing side and the other is from the retreating side. A simple model on the weld nugget formation of FSW is presented in this article.

  19. Effect of titanium addition on fracture toughness behavior of ZL108 alloy

    Institute of Scientific and Technical Information of China (English)

    WENG Yong-gang; LI Zi-jing; LIU Zhi-yong; LIU Wen-cai; WANG Ming-xing; SONG Tian-fu

    2006-01-01

    Two different titanium alloying methods were applied to ZL108 alloy for preparing specimens containing titanium. The specimens were tested on the MTS 810 material test system for studying their behavior of the plane strain fracture toughness KIC. The experimental data were analyzed by the statistical significance tests. The results show that the fracture toughness of the ZL108 alloy containing titanium is superior to that of common ZL108 alloy containing no titanium, but there is no significant difference for different titanium alloying methods. Therefore titanium addition is an effective method for improving the fracture toughness of the alloy ZL108.

  20. Worldwide clean energy system technology using hydrogen (WE-NET). subtask 5. Development of hydrogen transfer and storage technology (research and development of technologies for hydrogen transport and storage by hydrogen absorbing alloys); Suiso riyo kokusai clean energy system gijutsu (WE-NET). subtask 5. Suiso yuso chozo gijutsu no kaihatsu (bunsan yuso chozoyo suiso kyuzo gokin no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report describes a guiding principle of new hydrogen absorbing alloy design, case studies on the stationary hydrogen storage systems for multiple dwelling houses using hydrogen absorbing alloys and on the hydrogen fuel tank systems for a motor vehicle, and survey on development status in the world. As a result of the investigation of alloys, it was concluded that realization of hydrogen absorbing alloys with new target properties of the WE-NET Project is not easy through the current technology. It was found that two kinds of Mg-based and V-based high capacity materials must be selected as target alloys among current alloys, and that three techniques, i.e., ultra-fine microstructure, composite, and amorphousness, are effective for improving the hydrogen discharge property which has been a problem of these alloys. It was desired that the latest techniques are established by integrating these materials and techniques. It is necessary to promote the development of brake-through new materials by new concepts and technologies through the cooperation of national institutes, universities, and companies. 124 refs., 56 figs., 11 tabs.

  1. Bioinspired Soft Actuation System Using Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    Matteo Cianchetti

    2014-07-01

    Full Text Available Soft robotics requires technologies that are capable of generating forces even though the bodies are composed of very light, flexible and soft elements. A soft actuation mechanism was developed in this work, taking inspiration from the arm of the Octopus vulgaris, specifically from the muscular hydrostat which represents its constitutive muscular structure. On the basis of the authors’ previous works on shape memory alloy (SMA springs used as soft actuators, a specific arrangement of such SMA springs is presented, which is combined with a flexible braided sleeve featuring a conical shape and a motor-driven cable. This robot arm is able to perform tasks in water such as grasping, multi-bending gestures, shortening and elongation along its longitudinal axis. The whole structure of the arm is described in detail and experimental results on workspace, bending and grasping capabilities and generated forces are presented. Moreover, this paper demonstrates that it is possible to realize a self-contained octopus-like robotic arm with no rigid parts, highly adaptable and suitable to be mounted on underwater vehicles. Its softness allows interaction with all types of objects with very low risks of damage and limited safety issues, while at the same time producing relatively high forces when necessary.

  2. Interfacial characterization of SLM parts in multi-material processing: Metallurgical diffusion between 316L stainless steel and C18400 copper alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z.H., E-mail: AZHLIU@ntu.edu.sg; Zhang, D.Q., E-mail: ZHANGDQ@ntu.edu.sg; Sing, S.L., E-mail: SING0011@e.ntu.edu.sg; Chua, C.K., E-mail: MCKCHUA@ntu.edu.sg; Loh, L.E., E-mail: LELOH1@e.ntu.edu.sg

    2014-08-15

    Multi-material processing in selective laser melting using a novel approach, by the separation of two different materials within a single dispensing coating system was investigated. 316L stainless steel and UNS C18400 Cu alloy multi-material samples were produced using selective laser melting and their interfacial characteristics were analyzed using focused ion beam, scanning electron microscopy, energy dispersive spectroscopy and electron back scattered diffraction techniques. A substantial amount of Fe and Cu element diffusion was observed at the bond interface suggesting good metallurgical bonding. Quantitative evidence of good bonding at the interface was also obtained from the tensile tests where the fracture was initiated at the copper region. Nevertheless, the tensile strength of steel/Cu SLM parts was evaluated to be 310 ± 18 MPa and the variation in microhardness values was found to be gradual along the bonding interface from the steel region (256 ± 7 HV{sub 0.1}) to the copper region (72 ± 3 HV{sub 0.1}). - Highlights: • Multi-material processing was successfully implemented and demonstrated in SLM. • Bi-metallic laminates of steel/Cu were successfully produced with the SLM process. • A substantial amount of Fe and Cu diffusion was observed at the bond interface. • Good metallurgical bonding was obtained at the interface of the steel/Cu laminates. • Highly refined microstructure was obtained due to rapid solidification in SLM.

  3. Interaction of ions in water system containing copper-zinc alloy for boiler energy saving

    Institute of Scientific and Technical Information of China (English)

    MING Xing; LIANG Jinsheng; OU Xiuqin; TANG Qingguo; DING Yan

    2006-01-01

    Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally. The fouling was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray detector (EDX). The results show that the transfer of calcium and magnesium ions in heat-transfer-surface-water system is affected by zinc ions dissolved from the alloy because of primary battery reaction. Some calcium ions of calcium carbonate crystal are replaced by zinc ions, the growth of aragonite crystal nucleus is retarded, and the transition of calcium carbonate from aragonite to calcite is hampered.

  4. Advanced Materials for Mercury 50 Gas Turbine Combustion System

    Energy Technology Data Exchange (ETDEWEB)

    Price, Jeffrey

    2008-09-30

    injector development, multiple concepts including high thermal resistance thermal barrier coatings (TBC), oxide dispersion strengthened (ODS) alloys, continuous fiber ceramic composites (CFCC), and monolithic ceramics were evaluated before down-selection to the most promising candidate materials for field evaluation. Preliminary, component and sub-scale testing was conducted to determine material properties and demonstrate proof-of-concept. Full-scale rig and engine testing was used to validated engine performance prior to field evaluation at a Qualcomm Inc. cogeneration site located in San Diego, California. To ensure that the CFCC liners with the EBC proposed under this program would meet the target life, field evaluations of ceramic matrix composite liners in Centaur{reg_sign} 50 gas turbine engines, which had previously been conducted under the DOE sponsored Ceramic Stationary Gas Turbine program (DE-AC02-92CE40960), was continued under this program at commercial end-user sites under Program Subtask 1A - Extended CFCC Materials Durability Testing. The goal of these field demonstrations was to demonstrate significant component life, with milestones of 20,000 and 30,000 hours. Solar personnel monitor the condition of the liners at the field demonstration sites through periodic borescope inspections and emissions measurements. This program was highly successful at evaluating advanced materials and down-selecting promising solutions for use in gas turbine combustions systems. The addition of the advanced materials technology has enabled the predicted life of the Mercury 50 combustion system to reach 30,000 hours, which is Solar's typical time before overhaul for production engines. In particular, a 40 mil thick advanced Thermal Barrier Coating (TBC) system was selected over various other TBC systems, ODS liners and CFCC liners for the 4,000-hour field evaluation under the program. This advanced TBC is now production bill-of-material at various thicknesses up to 40

  5. Investigation of strain heterogeneities by laser scanning extensometry in strain ageing materials: application to zirconium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Graff, S.; Forest, S.; Strudel, J.L. [Centre des Materiaux / UMR 7633, Ecole des Mines de Paris / CNRS, BP 87, 91003 Evry (France); Dierke, H.; Neuhauser, H. [Institut fur Physik der Kondensierten Materie, 38106 Braunschweig (Germany); Prioul, C. [MSSMAT, Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France); Bechade, J.L. [SRMA, CEA Saclay, 91191 Gif sur Yvette (France)

    2005-07-01

    Laser scanning extensometry was used to detect and characterize propagating plastic instabilities such as the Luders bands at the millimeter scale. Spatio-temporal plastic heterogeneities are due to either static or dynamic strain ageing (SSA and DSA) phenomena. Regarding zirconium alloys, different type of heterogeneities were observed: their features strongly depended on mechanical test conditions. In one case, they appeared to be non propagating but preserved along the stress-strain curve and were associated with SSA effects such as stress peaks after relaxation periods or after unloading steps with waiting times. In other case, they appeared as non propagating but were not associated with SSA effects. (authors)

  6. Weldability and joining techniques for advanced fossil energy system alloys

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M. [Univ. of Tennessee, Knoxville, TN (United States)

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  7. FACADE SYSTEM MADE OF POROUS MATERIALS

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The proposed multi-component façade system is made of porous concretes employed both as bearing structures and for heat insulation and fireproofing purposes. The authors also provide their recommendations in respect of the mounting of the proposed façade system. The façade system considered in the article is composed of wall foam concrete blocks reinforced by basalt fibers (bearing elements of the structure, cellular concrete polystyrene (thermal insulation, and porous concrete (fireproofing and thermal insulation. Retained shuttering (in the fireproofing sections represents chrysolite cement sheets attached to the structures composed of glass-fiber plastic elements. The application of insulating porous concrete as a fireproofing material is based on the principle of adjustable stress-strained states of materials in the environment of variable pressure. This technology was developed at Moscow State University of Civil Engineering, and it was initially designated for the manufacturing of tailor-made products. The above concrete is also designated for retained shuttering and modified cavity masonry walls. Porous concrete that expands inside the fireproofing cavity ensures a tight contact both with the basic material and thermal insulation plates. The use of materials of the same origin (Portland cement means the formation of strong transition zones connecting the system components in the course of its hardening and further operation. The results of the thermotechnical calculation demonstrate that the thermal resistance registered on the surface of the wall that is 3 meters high (that has a 0.4 m fireproofing cavity is equal to 3.98 sq. m. C/Wt. The value of the coefficient of thermotechnical heterogeneity (r is equal to 0.86 with account for the thickness and thermal conductivity of point and linear elements. If the thermotechnical heterogeneity is taken into consideration, the thermal resistance of the proposed wall is equal to 3.42 m2 С/Wt.

  8. Development of materials supply system requirements

    OpenAIRE

    Brynning, Nicklas; Kihlström, Joakim

    2010-01-01

    In industry today, the need for excellent product development and realization in many different aspects is increasing. This calls for excellent quality, while at the same time time-to-market is increasingly important. A concurrent engineering (CE) approach is directed towards simultaneously developing different aspects of product realization in order to enhance both quality and speed. This thesis deals with the internal materials supply system (MSS) from a CE approach. Logistics aspects are o...

  9. Materials and economics of energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, H.E.; Dapkunas, S.J.

    1978-10-01

    In certain systems, such as MHD, solar electric power and fusion, the whole technology is almost totally dependent on either new materials or innovative designs or more probably some combination of these two. In more mature energy production systems an increase in availability, in many instances, can be achieved by thorough root cause analysis and relatively rapid research and development. In other energy systems, such as coal conversion, the economic feasibility of a process is directly linked to the degree of availability of the plant as well as the degree of redundancy required to achieve economic or competitive availability. Thus, the relegation of the field of materials of construction, whether of the R and D variety or the less glamorous but more sobering root cause, failure analysis type - to a necessary but decidedly secondary role is unwise and downright foolish. Comparatively modest investments in these areas can, if not entirely eliminate, at least substantially lower, the materials barrier for the economic production of energy.

  10. Leading research on supermetals. Part 2. Bulky material (Al system); Supermetal no sendo kenkyu. 2. Ogata sozai (aluminium kei)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    In order to find the higher critical strength, toughness and corrosion resistance of Al system materials than those obtained by conventional methods, crystal grain control was studied in a finer-grain region. The above characteristics of Al materials obtained by conventional technologies such as alloy element addition and heat treatment controlling crystal grains of several tens {mu}m are approaching critical values, resulting in poor characteristics for the latest needs. It has been confirmed experimentally in fundamental studies using small specimens that fine crystal grains of several {mu}m can remarkably enhance the above characteristics. Technology for creating mesoscopic structure-controlled materials was thus studied. In particular, creation of ultra-fine advanced Al alloy bulk materials by cryogenic processing method was selectively studied. The developmental approach and its issue were thus revealed for creating mesoscopic crystal structure by recovery and recrystallization of a highly distorted state obtained by cryogenic processing. 102 refs., 80 figs., 8 tabs.

  11. A radiation barrier alloy for long-term storage of special nuclear materials: Definition and preliminary assessment

    International Nuclear Information System (INIS)

    The radiation barrier alloy (RBA) concept is a method for introducing radioactive, chemical, and physical barriers for storing weapons-grade plutonium, and yet still allowing for accurate material control and accountability, as well as for retrieving the material by the host nation if desired. The radioactive and chemical barriers are achieved by fabricating the plutonium in the form of a plutonium-beryllium compound (PuBe13), which results in neutron emission resulting from (α,n) reactions within the compound and multiplication from (n,fission) processes in the plutonium. Preliminary physics analyses have been completed, as well as a general review of fabrication techniques and availability of the required materials. These studies revealed that dose levels in excess of 500 rem/h at a 1-m distance from the surface of the RBA assembly can be obtained. However, essential for achieving these dose levels is operation at a high level of neutron multiplication (keff ∼ 0.9). Criticality concerns, even under flooded conditions, can be eliminated through the use of a thermal-neutron-absorbing material (e.g., cadmium) either as a cladding material or a container material surrounding the RBA assembly. Fabrication techniques for the Pu-Be compound are well demonstrated and fully compatible with the RBA assembly fabrication. Data from disassembly of Pu-Be sources indicate that the compound is stable and no significant physical degradation occurs over a 40-yr time frame. There is no reason to believe that any additional problems exist for longer time frames, given that the components are designed for the appropriate lifetimes (i.e., adequately account for gas production). The materials required for RBA implementation are available in the required quantities, and cost of these materials is not prohibitive

  12. AB5-type Hydrogen Storage Alloy Modified with Ti/Zr Used as Anodic Materials in Borohydride Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Lianbang WANG; Chunan MA; Xinbiao MAO; Yuanming SUN; Seijiro SUDA

    2005-01-01

    Fuel cell using borohydride as the fuel has received much attention. AB5-type hydrogen storage alloy used as the anodic material instead of noble metals has been investigated. In order to restrain the generation of hydrogen and enhance the utilization of borohydride, Ti/Zr metal powders has been added into the parent LmNi4.78Mn0.22 (where Lm is La-richened mischmetal) alloy (LNM) by ball milling and heat treatment methods. It is found that the addition of Ti/Zr metal powders lowers the electrochemical catalytic activity of the electrodes, at the same time, restrains the generation of hydrogen and enhances the utilization of the fuel. All the results show that the hydrogen generation rate or the utilization of the fuel is directly relative to the electrochemical catalytic activity or the discharge capability of the electrodes. The utilization of the fuel increases with discharge current density. It is very important to find a balance between the discharge capability and the utilization of the fuel.

  13. MgB{sub 2} thin films grown on graphene/Ni–Mo alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Linghu, Kehuan, E-mail: linghukehuan@126.com [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Song, Qingjun [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China); Zhang, Huai [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Yang, QianQian [College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Zhang, Jibo; Wu, Qianhong; Nie, Ruijuan [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Dai, Lun [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China); Feng, Qingrong; Wang, Furen [School of Physics and State Key Laboratory for Artificial Structure and Mesoscopic Physics, Peking University, Beijing 100871 (China)

    2015-09-15

    Highlights: • Depositing MgB{sub 2} thin films on graphene/Ni–Mo alloy substrate by HPCVD is a completely new method. • The growth of MgB{sub 2} thin films in this system lays a good foundation of depositing MgB{sub 2} thick films. • We directly deposite MgB{sub 2} films on graphene(without transferring) which keeps graphene’s original morphology and properties. - Abstract: 200 nm Ni film is coated on 25 μm thick Mo foil, and graphene is grown on the Ni–Mo system by CVD method. After the annealing process of CVD, the Ni/Mo bilayer transforms into Ni–Mo alloy, then we have successfully fabricated MgB{sub 2} films on graphene/Ni–Mo alloy system via the hybrid physical–chemical vapor deposition (HPCVD) technique. The transition temperature T{sub c} onset is 38.25 K with a corresponding transition width of 0.75 K. The average thickness of MgB{sub 2} films is 200 nm (25% concentration B{sub 2}H{sub 6}). The critical current density derives from the magnetization measurement at 5 K is, j{sub c} (5 K, 0 T) = 9.6 × 10{sup 6} A/cm{sup 2}. We can easily deposite MgB{sub 2} on graphene/Ni–Mo alloy system with a lower B{sub 2}H{sub 6} concentration and less gas flow, which lays a good foundation for depositing MgB{sub 2} thick films. The graphene in this system is multilayer and with defects, it may act like an intermediary film for the growth of MgB{sub 2}, or a carbon-doping source.

  14. On amorphization and nanocomposite formation in Al–Ni–Ti system by mechanical alloying

    Indian Academy of Sciences (India)

    K Das; G K Dey; B S Murty; S K Pabi

    2005-11-01

    Amorphous structure generated by mechanical alloying (MA) is often used as a precursor for generating nanocomposites through controlled devitrification. The amorphous forming composition range of ternary Al–Ni–Ti system was calculated using the extended Miedema's semi-empirical model. Eleven compositions of this system showing a wide range of negative enthalpy of mixing (− mix) and amorphization (− amor) of the constituent elements were selected for synthesis by MA. The Al88Ni6Ti6 alloy with relatively small negative mix (−0.4 kJ/mol) and amor (−14.8 kJ/mol) became completely amorphous after 120 h of milling, which is possibly the first report of complete amorphization of an Al-based rare earth element free Al–TM–TM system (TM = transition metal) by MA. The alloys of other compositions selected had much more negative mix and amor; but they yielded either nanocomposites of partial amorphous and crystalline structure or no amorphous phase at all in the as-milled condition, evidencing a high degree of stability of the intermetallic phases under the MA environment. Hence, the negative mix and amor are not so reliable for predicting the amorphization in the present system by MA.

  15. 高分子合金膜体系的相容性%Polymer blend miscibility and compatibility study for polymer alloy membrane material modification

    Institute of Scientific and Technical Information of China (English)

    孙本惠

    2011-01-01

    Polymer alloy technologies enable two or more polymers to be combined to realize new properties and levels of performance that were not possible with the individual polymers themselves. Therefore, they have become the most feasible and effective methods to realize the modification of polymeric membrane materials. The miscibility and compatibility of the various polymeric components, and thus the formation of homogenious phase to multiphase systems in casting solution play a decisive role in influencing the physical properties of the membranes prepared from it. In this article, the principles of thermodynamic to evaluate the miscibility and compatibility between polymers in polymer blend or alloy systems were thoroughly reviewed and discussed, including the basic theory and models for polymer miscibility study, the analysis of the ternary phase diagram of polymer A-polymer Insolvent mixture system, the thermodynamics of polymer blend phase separation during phase inversion, the critical phase separation condition, and the theoretical prediction of the polymer blend miscibility and compatibility.%高分子膜材料的合金化是最为简便有效的膜材料改性方法,不同聚合物之间的相容性是决定高分子合金膜物理性质的关键因素.文章讨论了涉及高分子合金膜体系相容性的几个主要热力学基础问题,包括两组分聚合物相容性的相图分析、高分子共混物在相转化过程中发生相分离的热力学、相分离的临界条件、高分子合金体系相容性的理论预测.

  16. Alloy by design: A materials genome approach to advanced high strength stainless steels for low and high temperature applications

    NARCIS (Netherlands)

    Lu, Q.; Xu, W.; Van der Zwaag, S.

    2016-01-01

    We report a computational 'alloy by design' approach which can significantly accelerate the design process and substantially reduce the development costs. This approach allows simultaneously optimization of alloy composition and heat treatment parameters based on the integration of thermodynamic, th

  17. Corrosion kinetics of alloy Ni-22Cr-13Mo-3W as structural material in high level nuclear waste containers

    International Nuclear Information System (INIS)

    Alloy Ni-22Cr-13Mo-3W (also known as C-22) is one of the candidates to fabricate high level nuclear waste containers. These containers are designed to maintain isolation of the waste for a minimum of 10,000 years. In this period, the material must be resistant to corrosion. If the containers were in contact with water, it is assumed that alloy C-22 may undergo three different corrosion mechanisms: general corrosion, localized corrosion and stress corrosion cracking. This thesis discusses only the first two types of degradation. Electrochemical techniques such as amperometry, potentiometry, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) and non-electrochemical techniques such as microscopic observation, X-ray fluorescence (XRF) and X-ray photoelectron spectroscopy (XPS) were applied to study the corrosion behavior of alloy C-22 in 1 M NaCl, 25 C degrees saturated NaF (approximately 1 M) and 0,5 M NaCl + 0,5 M NaF solutions. Effects of temperature, pH and alloy thermal aging were analyzed. The corrosion rates obtained at 90 C degrees were low ranging from 0.04 μm/year to 0.48 μm /year. They increased with temperature and decreased with solution pH. Most of the impedance measurements showed a simply capacitive behavior. A second high-frequency time constant was detected in some cases. It was attributed to the formation of a nickel oxide and/or hydroxide at potentials near the reversible potential for this reaction. The active/passive transition detected in some potentiodynamic polarization curves was attributed to the same process. The corrosion potential showed an important increase after 24 hours of immersion. This increase in the corrosion potential was associated with an improvement of the passive film. The corrosion potential was always lower than the re-passivation potential for the corresponding media. The trans passive behavior of alloy C-22 was mainly influenced by temperature and solution chemistry. A clear trans passive peak

  18. The effect of silicide ceramic coatings on the high-temperature strength and plasticity of niobium alloys of the Nb-W-Mo-Zr system

    International Nuclear Information System (INIS)

    A study is made into short-term rupture strength and plasticity of 5VMTs alloy of Nb-W-Mo-Zr system and a 5VMTs-silicide ceramic coating composite material in vacuum, inert environment and in the air within a temperature range of 290-2070 K. The kinetics of defect generation and development both in the protective coating and the matrix is studied. The values of limiting plastic strains are determined at which the composite materials preserves its carrying capacity in high temperature aggressive and oxidizing gaseous media

  19. The relationship between viscosity and glass forming ability of Al-(Ni)-Yb alloy systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The dynamic viscosity of Al-Yb and Al-Ni-Yb superheated melts was measured using a torsional oscillation viscometer. The results show that the temperature dependence of viscosity fits the Arrhenius law well and the fitting factors are calculated. The amorphous ribbons of these alloys were produced by the melt spinning technique and the thermal properties were characterized by using a differential scanning calorimetry (DSC). E (the activation energy for viscous flow), which reflects the change rate of viscosity, has a good negative relation with the GFA in both Al-Yb and Al-Ni-Yb systems. However, there is no direct relation between liquidus viscosity (ηL) and GFA. The superheated fragility M can predict GFA in Al-Yb or Al-Ni-Yb alloy system.

  20. Determination of mutual diffusion coefficients in quaternary alloy systems

    International Nuclear Information System (INIS)

    Procedures of experimental study of mutual diffusion in four-component system are developed, limit ratios for diffusion coefficients are found at the transition from four component system to three-component one and experimental check of some of these ratios is carried out. Concentrational dependence of complete matrix of outer diffusion coefficients in Fe-Cr-Ni-Co system is determined. Limit correlations for this system are checked up at cobalt concentration yielding to zero

  1. Preparation of zirconium and zirconium-base alloy certified reference materials JAERI-Z11 to -Z18

    International Nuclear Information System (INIS)

    The Second Sub-Committee on Zircaloy Analysis was organized in April, 1978, under the Committee on Analytical Chemistry on Nuclear Fuels and Reactor Materials, JAERI, for the renewal of zirconium and zirconium-base alloy certified reference materials ( CRM's). The Sub-Committee decided certified values of major constituents and impurities in eight reference materials ( JAERI -Z11 to -Z18 ) in July, 1983, based on the results obtained by cooperative analysis during 1978 to 1983. CRM's JAERI-Z11 to -Z14 are Zircaloy-2 in the form of disk, 32 mm in diameter and 20 mm in thickness, and useful primarily for fluorescent X-ray and emission spectrographic analysis. CRMs JAERI-Z15 and -Z16 are zirconium in the form of plate, 30 mm square and 2 mm in the thickness, and specially designed for the analysis of hafnium at trace levels : 2 to 40 μg/g. CRM's JAERI -Z17 and -Z18 are Zircaloy-2 and -4, respectively, in the form of chips, packed in a glass bottle of which content is 25 g and useful for the analysis of carbon in Zircaloy. This report describes mainly preparation of certified reference materials, and homogeneity test by neutron activation analysis and fluorescent X-ray spectrometry. CRMs JAERI-Z11 to -Z14 have been distributed with provisional certificate since July, 1979. (author)

  2. Target system materials and engineering problems

    International Nuclear Information System (INIS)

    This paper discusses the common problems of target design. As a model for the discussion, the author considers a spallation source which is fed by a high power proton beam of the order of one megawatt. The materials used for the target station and particularly for the spallation target itself depend on whether the source is built for pulsed, modulated or continuous operation. The difference of materials used is mainly determined by the neutronics considerations. Depending on the choice of materials for the target systems, the characters of material problems met, are of somewhat different nature. It is recognized that for each target version quite specific difficulties have to be overcome. On the other hand, there is a whole set of problems which is common to all target versions. These are: heat load in region of proton beam interactions; thermal stress and cycling; and radiation damage. It is shown that solutions to the whole package of problems up to a beam power of 0 (1MW) have been found. The whole effort concentrates onto the region of the first few centimeters of beam penetration. Two solutions have been proposed: (1) Keep the power of proton beam limited and produce neutrons elsewhere in the target. and (2) Dilute the power by moving mechanically the target and the window. 8 refs., 11 figs

  3. Infrared imaging system using nanocarbon materials

    Science.gov (United States)

    Lai, King Wai Chiu; Xi, Ning; Chen, Hongzhi; Chen, Liangliang; Song, Bo

    2012-06-01

    Nanocarbon materials, such as carbon nanotubes and graphene, can potentially overcome the short comes in traditional infrared detector materials because of their excellent electrical and optical properties such as adjustable electrical band gap, low dark current, fast optical response time etc. This paper will present the development of an infrared imaging system that is capable of infrared imaging without cooling. The sensing elements of the system are carbon nanotubes and graphene. When they are illumined by an infrared light, the nano devices generate photocurrents, respectively. As a result, infrared images can be presented based on using compressive sensing after the collection of photocurrent from the nano devices. The development of this imaging system overcomes two major difficulties. First, the system uses singlepixel nano photodetector, so the pixel crosstalk phenomena of conventional sensor arrays can be eliminated. Second, the requirement of single-pixel unit reduces the manufacturing difficulties and costs. Under this compressive sensing camera configuration, 50 × 50 pixel infrared images can be reconstructed efficiently. The results demonstrated a possible solution to overcome the limitation of current infrared imaging.

  4. Optoelectronic inventory system for special nuclear material

    Energy Technology Data Exchange (ETDEWEB)

    Sieradzki, F.H.

    1994-01-01

    In support of the Department of Energy`s Dismantlement Program, the Optoelectronics Characterization and Sensor Development Department 2231 at Sandia National Laboratories/New Mexico has developed an in situ nonintrusive Optoelectronic Inventory System (OIS) that has the potential for application wherever periodic inventory of selected material is desired. Using a network of fiber-optic links, the OIS retrieves and stores inventory signatures from data storage devices (which are permanently attached to material storage containers) while inherently providing electromagnetic pulse immunity and electrical noise isolation. Photovoltaic cells (located within the storage facility) convert laser diode optic power from a laser driver to electrical energy. When powered and triggered, the data storage devices sequentially output their digital inventory signatures through light-emitting diode/photo diode data links for retrieval and storage in a mobile data acquisition system. An item`s exact location is determined through fiber-optic network and software design. The OIS provides an on-demand method for obtaining acceptable inventory reports while eliminating the need for human presence inside the material storage facility. By using modularization and prefabricated construction with mature technologies and components, an OIS installation with virtually unlimited capacity can be tailored to the customer`s requirements.

  5. Wear behavior of 2-1/4 Cr-1 Mo tubing against alloy 718 tube-support material in sodium-cooled steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, W L

    1983-05-01

    A series of prototypic steam generator 2-{1/4} Cr-1 Mo tube/alloy 718 tube support plate wear tests were conducted in direct support of the Westinghouse Nuclear Components Division -- Breeder Reactor Components Project Large Scale steam Generator design. The initial objective was to verify the acceptable wear behavior of softer, over-aged'' alloy 718 support plate material. For all interfaces under all test conditions, resultant wear damage was adhesive in nature with varying amounts of 2-{1/4} Cr-1 Mo tube material being adhesively transferred to the alloy 718 tube supports. Maximum tube wear depths exceeded the initially established design allowable limit of 127 {mu}m (.005 in.) at 17 of the 18 interfaces tested. A decrease in contact stresses produced acceptable tube wear depths below a readjusted maximum design allowable value of 381 {mu}m (.015 in.). Additional conservatisms associated with the simulation of a 40-year lifetime of rubbing in a one-week laboratory test provided further confidence that the 381 {mu}m maximum tube wear allowance would not be exceeded in service. Softer, over-aged'' alloy 718 material was found to produce slightly less wear damage on 2-{1/4} Cr-1 Mo tubing than fully age hardened material. Also, air formed oxide films on the alloy 718 reduced initial tube wear and delayed the onset of adhesive surface damage. However, at high surface stress levels, these films were not sufficiently stable to provide adequate long term protection from adhesive wear. The results of the present work and those of previous test programs suggest that the successful in-sodium tribological performance of 2-{1/4} Cr-1 Mo/alloy 718 rubbing couples is dependent upon the presence of lubricative surface films, such as oxides and/or surface reaction or deposition products. 11 refs., 13 figs., 4 tabs.

  6. Characterization of novel heterophasic powdered silicide-type material for high-temperature protection systems

    International Nuclear Information System (INIS)

    Novel multicomponent heterophasic powdered material of silicide-type is presented. The powdered material is intended for forming high-temperature protective multifunction coatings able to protect different hot-loaded structural elements of aerospace industry from refractory metals alloys under severe oxidizing conditions in high-enthalpy and super/hypersonic oxygen-containing gas flows. The powdered material base on complexly composition of Si-Ti-Mo system modified with B,Y,W. Technological conception of its obtaining and powder making process are examined. The powders were worked out in accordance with early performed functional structural model of special materials for coatings with the increased self-healing ability. The coatings can be deposited from the specially prepared abovementioned powders by plasma spraying processes or any one of other coating methods ensuring the conservation of morphological peculiarities of microstructure and phase composition of powdered material (detonation spraying technique, from slurry ...). Finally the results of some properties of novel heterophasic silicidetype powders and some properties of protective coating deposited on the niobium base alloys by means of plasma spraying technique are presented. (author)

  7. Two-dimensional B-C-O alloys: a promising class of 2D materials for electronic devices

    Science.gov (United States)

    Zhou, Si; Zhao, Jijun

    2016-04-01

    Graphene, a superior 2D material with high carrier mobility, has limited application in electronic devices due to zero band gap. In this regard, boron and nitrogen atoms have been integrated into the graphene lattice to fabricate 2D semiconducting heterostructures. It is an intriguing question whether oxygen can, as a replacement of nitrogen, enter the sp2 honeycomb lattice and form stable B-C-O monolayer structures. Here we explore the atomic structures, energetic and thermodynamic stability, and electronic properties of various 2D B-C-O alloys using first-principles calculations. Our results show that oxygen can be stably incorporated into the graphene lattice by bonding with boron. The B and O species favor forming alternate patterns into the chain- or ring-like structures embedded in the pristine graphene regions. These B-C-O hybrid sheets can be either metals or semiconductors depending on the B : O ratio. The semiconducting (B2O)nCm and (B6O3)nCm phases exist under the B- and O-rich conditions, and possess a tunable band gap of 1.0-3.8 eV and high carrier mobility, retaining ~1000 cm2 V-1 s-1 even for half coverage of B and O atoms. These B-C-O alloys form a new class of 2D materials that are promising candidates for high-speed electronic devices.Graphene, a superior 2D material with high carrier mobility, has limited application in electronic devices due to zero band gap. In this regard, boron and nitrogen atoms have been integrated into the graphene lattice to fabricate 2D semiconducting heterostructures. It is an intriguing question whether oxygen can, as a replacement of nitrogen, enter the sp2 honeycomb lattice and form stable B-C-O monolayer structures. Here we explore the atomic structures, energetic and thermodynamic stability, and electronic properties of various 2D B-C-O alloys using first-principles calculations. Our results show that oxygen can be stably incorporated into the graphene lattice by bonding with boron. The B and O species favor

  8. Theory-Guided Materials Design of Multi-Phase Ti-Nb Alloys with Bone-Matching Elastic Properties

    Directory of Open Access Journals (Sweden)

    Jörg Neugebauer

    2012-10-01

    Full Text Available We present a scale-bridging approach for modeling the integral elasticresponse of polycrystalline composite that is based on a multi-disciplinary combination of(i parameter-free first-principles calculations of thermodynamic phase stability andsingle-crystal elastic stiffness; and (ii homogenization schemes developed forpolycrystalline aggregates and composites. The modeling is used as a theory-guidedbottom-up materials design strategy and applied to Ti-Nb alloys as promising candidatesfor biomedical implant applications. The theoretical results (i show an excellent agreementwith experimental data and (ii reveal a decisive influence of the multi-phase character ofthe polycrystalline composites on their integral elastic properties. The study shows thatthe results based on the density functional theory calculations at the atomistic level canbe directly used for predictions at the macroscopic scale, effectively scale-jumping severalorders of magnitude without using any empirical parameters.

  9. Development of fine-grain size titanium 6Al–4V alloy sheet material for low temperature superplastic forming

    International Nuclear Information System (INIS)

    Fine-grained titanium 6Al–4V alloy, which typically has a grain size of about 1–2 μm, can be made to superplastic form at around 800 °C with special processing. The normal temperature for superplastic forming (SPF) with conventional titanium 6Al–4V sheet material is 900 °C. The lower temperature performance is of interest to the Boeing Company because it can be exploited to achieve significant cost savings in processing by reducing the high-temperature oxidation of the SPF dies, improving the heater rod life for the hot presses, increasing operator safety and replacing the chemical milling operation to remove alpha case contamination with a less intensive nitric hydrofluoric acid etchant (pickle). In this report, room temperature tensile tests and elevated temperature constant strain rate tensile tests of fine-grained Ti–6Al–4V sheets provided by the Baoti Company of Xi'an, China, were conducted according to the test method standards of ASTM-E8 and ASTM-E2448. The relationships among the processing parameters, microstructure and superplastic behavior have been analyzed. The results show that two of the samples produced met the Boeing minimum requirements for low-temperature superplasticity. The successful material was heat-treated at 800 °C subsequent to hot rolling above the beta transus temperature, Tβ-(150–250 °C). It was found that the sheet metal microstructure has a significant influence on superplastic formability of the Ti–6Al–4V alloy. Specifically, fine grains, a narrow grain size distribution, low grain aspect ratio and moderate β phase volume fraction can contribute to higher superplastic elongations

  10. Mutual alloying of XAs (X=Ga, In, Al) materials: Tuning the optoelectronic and thermodynamic properties for solar energy applications

    KAUST Repository

    Haq, Bakhtiar Ul

    2014-02-01

    In the present work we did mutual alloying of the versatile XAs (X=Ga, In, Al) materials in order to improve their efficiency and enhance their range of technological applications using state of the art first principles method. We investigate the structural, electronic and thermodynamic properties of Ga1-xAlxAs, Ga1-xInxAs and In1-xAlxAs for x=0.25, 0.50, and 0.75. Calculations have been performed using the density functional theory (DFT) as implemented within the full potential linearized augmented plane wave plus local orbital (FP-LAPW+lo) method. For exchange and correlation energy treatment, we employed the local density approximations (LDA) as proposed by Wang and Perdew and the generalized gradient approximation (GGA) from Perdew et al. proposed. To calculate the accurate band structure, recently modified Becke Johnson (mBJ) potential was suggested as an alternative. Our calculations show a linear fall in the lattice constant in contrast to linear rise in bulk moduli of Ga1-xAlxAs and In1-xAlxAs with the increase of Al concentration. However the change of indium concentration in Ga1-xInxAs is displaying a reverse effect. The energy band gap of Ga1-xAlxAs and In1-xAlxAs was found to be increased, where a crossover from direct to indirect band gap has been observed with the increase of Al concentration. This direct to indirect crossover was found at 93.4% of Al concentration for Ga1-xAlxAs and at 84.63% of Al concentration for In1-xAlxAs. The effect of the mutual alloying of XAs materials on the thermodynamic properties is comprehensively reported. © 2013 Elsevier Ltd.

  11. 机械合金化制备亚稳材料%Preparation of Nonequilibrium Materials by Mechanical Alloying

    Institute of Scientific and Technical Information of China (English)

    胡壮麒; 张海峰; 刘智光; 叶荔蕾; 范国江; 生红卫

    2001-01-01

    During the recent years, mechanical alloysing/ball milling was widely employed to synthesize the new kinds of nonequilibrium materials, namely, by means of solid state reactions to form materials with metastable structures. In the process of ball milling, starting powders are subjected to the repeated fracture and cold welding that lead to the accumulation of internal defects and stored energy. Consequently, the microstructures of the milled powders are refined. Abrupt temperature rise, amorphization, local melting and formation of metastable phase have been observed.Mechanical alloying also has a remarkable influence on the microstructure and mechanical properties. Some differences have also been found in the formation products produced by mechanical alloying and rapid quenching, for example, on melting point depression, hardenability and thermal stability.%最近十几年来,机械合金化技术被广泛应用于制备和合成亚稳材料。这是一种通过固态反应生成具有亚稳结构和组织的新材料。在球磨过程中,原始粉末经受反复的破裂和冷焊,积聚大量的内部缺陷和储能,促使组织细化。实验中观察到突然的温升,非晶化,局部的熔化和亚稳相的形成。机械合金化也对力学性能产生很大影响,比较机械合金化技术和快淬技术制备同一种亚稳材料,发现在熔点降低,硬度和热稳定性等方面有差异。

  12. 汽车保险杠使用PA/EGMA合金材料的研究%Research on Automobile Bumper using the PA6/EGMA Alloy Materials

    Institute of Scientific and Technical Information of China (English)

    林博

    2015-01-01

    The PA6/EGMA alloy was prepared using EGMA as compatibilizer and toughener in a reactive extrusion process. The optimum processing parameter and formulation for the PA6/EGMA alloy of Car Bumper new materials were determine, blends of the alloy could be improved. The alloy had a good process ability, higher impact resistance and spray-paint easily, being a new product excellent comprehensive performance impact. The PA6/EGMA alloy Show the non-viscoelastic polymer materials in high speed impact still has higher toughness properties.%采用聚乙烯—甲基丙烯酸缩水甘油酯(EGMA)作为增容剂和增韧剂,利用反应增容技术制备了PA6/EGMA的合金。通过试验确定了PA/EGMA合金汽车保险杠新材料的最佳配方,提高合金的综合性能。该合金具有良好的加工性能,较高的抗冲击性能并易于喷涂,是综合性能优良的抗冲击新产品。PA6/EGMA 合金表现出非粘弹性高分子材料在高速冲击时仍然具有较高的韧性的特性。

  13. Minimizing Segregation During the Controlled Directional Solidification of Dendritic Alloys Publication: Metallurgical and Materials Transactions

    Science.gov (United States)

    Grugel, R. N.; Fedoseyev, A. I.; Kim, S.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Gravity-driven thermosolutal convection that arises during controlled directional solidification (DS) of dendritic alloys promotes detrimental macro-segregation (e.g. freckles and steepling) in products such as turbine blades. Considerable time and effort has been spent to experimentally and theoretically investigate this phenomena; although our knowledge has advanced to the point where convection can be modeled and accurately compared to experimental results, little has been done to minimize its onset and deleterious effects. The experimental work demonstrates that segregation can be. minimized and microstructural uniformity promoted when a slow axial rotation is applied to the sample crucible during controlled directional solidification processing. Numerical modeling utilizing continuation and bifurcation methods have been employed to develop accurate physical and mathematical models with the intent of identifying and optimizing processing parameters.

  14. Influence of material modeling on earing prediction in cup drawing of AA3104 aluminum alloy sheet

    Science.gov (United States)

    Fukumasu, H.; Kuwabara, T.; Takizawa, H.

    2016-08-01

    In-plane biaxial tension and combined tension-compression tests are carried out for AA3104 aluminum alloy sheets. Linear stress paths are applied to cruciform specimens to measure the contours of plastic work in the stress space and the directions of plastic strain rates at each stress path. Coefficients α 1- α 8 and exponent M of the Yld2000-2d yield function are determined to minimize the mean square error of the analytical yield locus from a measured work contour. The values of the weighting coefficients in the evaluation of the error are varied to check the effect of a specific stress state on the earing behavior. The effects of the combinations of the weighting coefficients on the accuracy of earing prediction in the cup drawing process are discussed.

  15. The Development of HfO2-Rare Earth Based Oxide Materials and Barrier Coatings for Thermal Protection Systems

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan James

    2014-01-01

    Advanced hafnia-rare earth oxides, rare earth aluminates and silicates have been developed for thermal environmental barrier systems for aerospace propulsion engine and thermal protection applications. The high temperature stability, low thermal conductivity, excellent oxidation resistance and mechanical properties of these oxide material systems make them attractive and potentially viable for thermal protection systems. This paper will focus on the development of the high performance and high temperature capable ZrO2HfO2-rare earth based alloy and compound oxide materials, processed as protective coating systems using state-or-the-art processing techniques. The emphasis has been in particular placed on assessing their temperature capability, stability and suitability for advanced space vehicle entry thermal protection systems. Fundamental thermophysical and thermomechanical properties of the material systems have been investigated at high temperatures. Laser high-heat-flux testing has also been developed to validate the material systems, and demonstrating durability under space entry high heat flux conditions.

  16. Welding of aluminum alloys through thermite like reactions in Al-CuO-Ni system

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami Motlagh, Ehsan, E-mail: ehsan.bahramimotlagh@stu-mail.um.ac.ir [Department of Materials Science and Engineering, Engineering Faculty, Ferdowsi University of Mashhad, P.O. Box 9177948944, Mashhad (Iran, Islamic Republic of); Vahdati Khaki, Jalil; Haddad Sabzevar, Mohsen [Department of Materials Science and Engineering, Engineering Faculty, Ferdowsi University of Mashhad, P.O. Box 9177948944, Mashhad (Iran, Islamic Republic of)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Combustion synthesis reactions were utilized for welding of aluminum alloys. Black-Right-Pointing-Pointer A composite joint reinforced by different intermetallic compounds was obtained. Black-Right-Pointing-Pointer Using metal oxides as a part of raw materials makes the welding process economical. Black-Right-Pointing-Pointer Furthermore, this process introduces new applications for thermite reactions. - Abstract: In this work, first, a metastable composite powder of '14Al-3CuO-Ni' with a decreased ignition temperature was obtained via Arrested Reactive Milling (ARM), then this exothermic blend was used for welding of 1100 Aluminum alloy. The reactive media and the weld zones were investigated using scanning electron microscope. X-ray diffraction experiment and morphological investigations accompanied with the EDS analyses were carried out in order to evaluate the reactions' products. Vickers microhardness profile across the joint and the shear strength of the joints were determined. The weld zone thickness in each of the parent alloys was measured to be 750 {mu}m, approximately. Results showed that different reactions occurring during the process lead to the in situ formation of different intermetallic compounds such as Al{sub 3}Ni{sub 2} and Al{sub 7}Cu{sub 4}Ni as well as Al{sub 2}O{sub 3} nanoparticles at the interface. Thus, this area has the maximum hardness (80-90 VHN) and the minimum hardness of 35 VHN belongs to the parent alloys. The mean shear strength of the obtained joints was 27 MPa.

  17. RESEARCH OF GAS-FORMING ABILITY OF THE MATERIALS USED AT DEVELOPMENT OF DIVIDING COVERINGS FOR THE MOLDS OF CASTING OF ALUMINUM ALLOYS UNDER PRESSURE

    Directory of Open Access Journals (Sweden)

    A. M. Mihaltsov

    2012-01-01

    Full Text Available The methods of carrying out of experiments by determination of gas creating ability of different materials which are of interest from the point of view of molding of aluminum alloys under pressure are given and described, and the results of research are presented as well.

  18. Nanostructural Materials for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2011-01-01

    Full Text Available The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

  19. Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments.

    Energy Technology Data Exchange (ETDEWEB)

    Alexandreanu, B.; Chopra, O. K.; Shack, W. J.

    2008-05-05

    In light water reactors, components made of nickel-base alloys are susceptible to environmentally assisted cracking. This report summarizes the crack growth rate results and related metallography for field and laboratory-procured Alloy 600 and its weld alloys tested in pressurized water reactor (PWR) environments. The report also presents crack growth rate (CGR) results for a shielded-metal-arc weld of Alloy 182 in a simulated PWR environment as a function of temperature between 290 C and 350 C. These data were used to determine the activation energy for crack growth in Alloy 182 welds. The tests were performed by measuring the changes in the stress corrosion CGR as the temperatures were varied during the test. The difference in electrochemical potential between the specimen and the Ni/NiO line was maintained constant at each temperature by adjusting the hydrogen overpressure on the water supply tank. The CGR data as a function of temperature yielded activation energies of 252 kJ/mol for a double-J weld and 189 kJ/mol for a deep-groove weld. These values are in good agreement with the data reported in the literature. The data reported here and those in the literature suggest that the average activation energy for Alloy 182 welds is on the order of 220-230 kJ/mol, higher than the 130 kJ/mol commonly used for Alloy 600. The consequences of using a larger value of activation energy for SCC CGR data analysis are discussed.

  20. Gating System Design for a Magnesium Alloy Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The gating system of a cylindrical magnesium casting has been designed by using multiple objective optimization and Taguchi method. Mold filling and solidification processes were simulated by using MAGMASOFT(R).The simulation results indicate that the gating system design has a significant effect on the quality of magnesium castings. In an effort to obtain the optimal design of gating system, the signal-to-noise (S/N) ratio was used to analyze the effect of various gating designs on cavity filling and casting quality by using a weighting method based on the design of an orthogonal array. Four gating system parameters, namely, ingate height,ingate width, runner height, runner width, were optimized with a consideration of multiple objective criteria including filling velocity, shrinkage porosity and product yield.

  1. Failure analysis of fusion clad alloy system AA3003/AA6xxx sheet under bending

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y., E-mail: shiyh@mcmaster.ca [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Jin, H. [Novelis Global Technology Center, P.O. Box 8400, Kingston, Ontario, Canada K7L 5L9 (Canada); Wu, P.D. [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Lloyd, D.J. [Aluminum Materials Consultants, 106 Nicholsons Point Road, Bath, Ontario, Canada K0H 1G0 (Canada); Embury, D. [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2014-07-29

    An ingot of AA6xxx Al–Si–Mg–Cu alloy clad with AA3003 Al–Mn alloy was co-cast by Fusion technology. Bending tests and numerical modeling were performed to investigate the potential for sub-surface cracking for this laminate system. To simulate particle-induced crack initiation and growth, both random and stringer particles have been selected to mimic the particle distribution in the tested samples. The morphology of cracking in the model was similar to that observed in clad sheet tested in the Cantilever bend test. The crack initiated in the core close to the clad-core interface where the strain in the core is highest, between particles or near particles and propagates along local shear bands in the core, while the clad layer experiences extreme thinning before failure.

  2. Direct Measurement of the Metastable Liquid Miscibility Gap in Fe-Co-Cu Ternary Alloy System

    Institute of Scientific and Technical Information of China (English)

    CAO Chong-De; Georg P.G(O)RLER

    2005-01-01

    @@ The metastable liquid-liquid phase separation in undercooled Fe-Co-Cu ternary alloy melts (XCu = 0.10-0.84;XCo:XFe = 1:3,1:1 and 3:1) is investigated by differential thermal analysis in combination with glass fluxing technique. In almost every case, the undercooling of the homogeneous alloy melt was sufficient to reach the boundary line of the submerged miscibility gap. The differential-thermal-analysis signals indicate that this separation into a (Fe, Co)-rich liquid phase L1 and a Cu-rich liquid L2 is exothermic and proceeds until the rapid solidification of the L1 phase occurs. At a given Cu concentration and with the increase of Co content, the phase separation temperatures decrease monotonically between the corresponding values of the boundary systems Fe-Cu and Co-Cu. The boundary lines of the miscibility gap, which are determined for the three quasi-binary cross-sections of the (Fe, Co)-Cu alloy system, show remarkably flat domes. The occurrence of the liquid phase separation shows an evident influence on the subsequent γ-Fe(Co, Cu)→α-Fe(Co, Cu) solid phase transformation.

  3. Material composition and nuclear data libraries' influence on nickel-chromium alloys activation evaluation: a comparison with decay heat experiments

    International Nuclear Information System (INIS)

    The paper presents the activation analyses on Inconel-600 nickel-chromium alloy. Three activation data libraries, namely the EAF-4.1, the EAF-97 and the FENDL/A-2, and the FENDL/D-2 decay data library, have been used to perform the calculation with the European activation code ANITA-4/M. The neutron flux distribution into the material samples was provided by JAERI as results of 3D Monte-Carlo MCNP transport code experiment simulation. A comparison with integral decay heat measurement performed at the Fusion Neutronics Source (FNS), JAERI, Tokai, Japan, is used to validate the computational approach. The calculation results are given and discussed. The impact of the material composition, including impurities, on the decay heat of samples irradiated in fusion-like neutron spectra is assessed and discussed. The discrepancies calculations-experiments are within the experimental errors, that is between 6% and 10%, except for the short cooling times (less than 40 min after the end of irradiation). To improve calculation consistency with the experimental results, the knowledge of the material impurities content is mandatory

  4. Hazardous materials information hotline using System 2000

    International Nuclear Information System (INIS)

    The Center for Assessment of Chemical and Physical Hazards (CACPH) at Brookhaven National Laboratory (BNL) has developed a computer hotline service for the Department of Energy (DOE) and its contractors. This service provides access to health and safety information for over 800 chemicals and hazardous materials. The data base uses System 2000 on a CDC 6600 and provides information on the chemical name and its synonyms, 17 categories of health and safety information, composition of chemical mixtures, categories of chemicals, use and hazards, and physical, chemical and toxicity attributes. In order to make this information available to people unfamiliar with System 2000, a user-friendly interface was developed using a Fortran PLEX Program. 1 reference, 1 figure

  5. Integration mockup and process material management system

    Science.gov (United States)

    Verble, Adas James, Jr.

    1992-02-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  6. Integration mockup and process material management system

    Science.gov (United States)

    Verble, Adas James, Jr.

    1992-01-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  7. Composite materials for rail transit systems

    Science.gov (United States)

    Griffin, O. Hayden, Jr.; Guerdal, Zafer; Herakovich, Carl T.

    1987-01-01

    The potential is explored for using composite materials in urban mass transit systems. The emphasis was to identify specific advantages of composite materials in order to determine their actual and potential usage for carbody and guideway structure applications. The literature was reviewed, contacts were made with major domestic system operators, designers, and builders, and an analysis was made of potential composite application to railcar construction. Composites were found to be in use throughout the transit industry, usually in secondary or auxiliary applications such as car interior and nonstructural exterior panels. More recently, considerable activity has been initiated in the area of using composites in the load bearing elements of civil engineering structures such as highway bridges. It is believed that new and improved manufacturing refinements in pultrusion and filament winding will permit the production of beam sections which can be used in guideway structures. The inherent corrosion resistance and low maintenance characteristics of composites should result in lowered maintenance costs over a prolonged life of the structure.

  8. An automatic system to measure material's resistance to stable crack initiation

    International Nuclear Information System (INIS)

    The unloading compliance technique has become the preferred single specimen method for evaluating the fracture toughness of materials. It involves control of the testing machine as well as data acquisition and analysis using computers. This paper describes in detail the development of a simple experimental system and related software. The method has been applied in order to determine the temperature dependence of fracture toughness of a low-alloy Cr-Mo steel. Results are compared with both measurements at the VTT Espoo and measurements based on a multiple specimen method. (orig.)

  9. Computational Materials: Modeling and Simulation of Nanostructured Materials and Systems

    Science.gov (United States)

    Gates, Thomas S.; Hinkley, Jeffrey A.

    2003-01-01

    The paper provides details on the structure and implementation of the Computational Materials program at the NASA Langley Research Center. Examples are given that illustrate the suggested approaches to predicting the behavior and influencing the design of nanostructured materials such as high-performance polymers, composites, and nanotube-reinforced polymers. Primary simulation and measurement methods applicable to multi-scale modeling are outlined. Key challenges including verification and validation of models are highlighted and discussed within the context of NASA's broad mission objectives.

  10. Nuclear Magnetic Resonance Study of the Unconventional Kondo Alloy System Uranium COPPER(5-X) Palladium(x)

    Science.gov (United States)

    Bernal, Oscar Orlando

    The intermetallic Kondo alloy system UCu _{5-x}Pd_{x } is one of a number of recently-discovered Kondo materials which exhibit deviations from Fermi liquid behavior in their thermodynamic and transport properties down to micro-Kelvin temperatures. Studying local electronic structure by nuclear magnetic resonance techniques (NMR) in this unconventional system, we find anomalous behavior of NMR parameters versus magnetic susceptibility chi in UCu_4Pd and UCu_{3.5}Pd_ {1.5}. Metallic alloys containing magnetic impurities usually display a linear relation between the susceptibility and the Knight shift and its distribution, the magnetic broadening. In UCu_{5 -x}Pd_{x}, as the temperature is lowered, it is found that for both concentrations the magnetic broadening of the ^{63}Cu NMR spectra grows non-linearly with respect to chi, reaching enhancements at the lowest temperatures of ~100% over the values expected from a high-temperature linear relation. Enhancement of the linewidth over the susceptibility might indicate the possibility of U-spin freezing, as observed in some dilute Kondo alloys. The absence of any anomalies in either the specific heat or the magnetic susceptibility of these samples suggests, however, that spin freezing does not account for the observations, and that the enhancement is related to intrinsic behavior of the paramagnetic alloys. Smaller but similar anomalies are found for the isotropic and axial components of the Knight shift {cal K} as functions chi in the two materials. {cal K} presents a linear relation with chi only down to ~30 K. Below this temperature, the absolute value of the Knight-shift components grows more slowly than would be expected from extrapolating their high temperature behavior, suggesting temperature-dependent transferred-hyperfine fields at the Cu sites or a temperature-dependent lineshape asymmetry. We interpret these observations in terms of disorder of the density of conduction-electron states (DOS). A simple model of

  11. Lead-Cooled Fast Reactor Systems and the Fuels and Materials Challenges

    Directory of Open Access Journals (Sweden)

    T. R. Allen

    2007-01-01

    Full Text Available Anticipated developments in the consumer energy market have led developers of nuclear energy concepts to consider how innovations in energy technology can be adapted to meet consumer needs. Properties of molten lead or lead-bismuth alloy coolants in lead-cooled fast reactor (LFR systems offer potential advantages for reactors with passive safety characteristics, modular deployment, and fuel cycle flexibility. In addition to realizing those engineering objectives, the feasibility of such systems will rest on development or selection of fuels and materials suitable for use with corrosive lead or lead-bismuth. Three proposed LFR systems, with varying levels of concept maturity, are described to illustrate their associated fuels and materials challenges. Nitride fuels are generally favored for LFR use over metal or oxide fuels due to their compatibility with molten lead and lead-bismuth, in addition to their high atomic density and thermal conductivity. Ferritic/martensitic stainless steels, perhaps with silicon and/or oxide-dispersion additions for enhanced coolant compatibility and improved high-temperature strength, might prove sufficient for low-to-moderate-temperature LFRs, but it appears that ceramics or refractory metal alloys will be necessary for higher-temperature LFR systems intended for production of hydrogen energy carriers.

  12. Extended solid solubility of a Co-Cr system by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt-Cantera, J.A. [Area Academica de Ciencias de la Tierra y Materiales, UAEH Carr. Pachuca-Tulancingo Km. 4.5, Pachuca, Hidalgo 42184 (Mexico); Sanchez-De Jesus, F., E-mail: fsanchez@uaeh.edu.mx [Area Academica de Ciencias de la Tierra y Materiales, UAEH Carr. Pachuca-Tulancingo Km. 4.5, Pachuca, Hidalgo 42184 (Mexico); Torres-Villasenor, G. [Instituto de Investigaciones en Materiales-UNAM, Apdo. Postal 70-360, 04510 Mexico, DF (Mexico); Bolarin-Miro, A.M. [Area Academica de Ciencias de la Tierra y Materiales, UAEH Carr. Pachuca-Tulancingo Km. 4.5, Pachuca, Hidalgo 42184 (Mexico); Cortes-Escobedo, C.A. [Centro de Investigacion e Innovacion Tecnologica del IPN Cda. CECATI S/N, Col. Sta. Catarina, Azcapotzalco, 02250 Mexico, DF (Mexico)

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer Solubility of the Co-Cr system is modified by means of Mechanical Alloying (MA). Black-Right-Pointing-Pointer MA induces the formation of new solid solutions of Co-Cr system in non-equilibrium. Black-Right-Pointing-Pointer MA promote the formation of metastable Co-Cr phases with greater solubility. - Abstract: Mechanical alloying, MA, has been successfully used to extend the limits of solid solubility in many commercially important metallic systems. The aim of this work is to demonstrate that MA modifies the solid solubility of the Co-Cr system. Co and Cr elemental powders were used as precursors and mixed in an adequate weight ratio to obtain Co{sub 100-x}Cr{sub x} (0 {<=} x {<=} 100, {Delta}x = 10) to study the effect of mechanical processing in the solubility of the Co-Cr system. Processing was carried out at room temperature in a shaker mixer mill using vials and balls of hardened steel as milling media with a ball:powder weight ratio of 10:1. Crystalline structure characterization of the milled powders was conducted using X-ray diffraction, and phase transformations as a function of composition were analyzed. Thermal analysis confirmed structural changes occurred in the mechanically alloyed powders. The evolution of the phase transformations with composition is reported for each composition. The results showed that after high energy ball milling for 7 h, the solid solubility between Co and Cr could be evidently extended, despite the low solid solubility at the equilibrium conditions of this system. Additionally, the micrographs of the milled powders showed that increasing composition of chromium changes the shape and size of the particles while simultaneously reducing their agglomeration; this effect is possibly attributed to the brittleness of elemental chrome.

  13. Vibrational properties at the ordered metallic surface alloy system Au(110)-1×2-Pd

    Science.gov (United States)

    Kheffache, Sedik; Chadli, Rabah; Khater, Antoine

    2016-06-01

    We present a calculation for the vibrational properties of the ordered surface alloy Au(110)-1×2-Pd on a crystalline substrate of Au. The surface phonon dispersion curves and the local vibrations densities of states (LDOS) are calculated in the harmonic approximation for the system, using the phase field matching theory (PFMT) method and associated real space Green’s functions. In particular, it is shown that the surface alloy presents optic vibrational modes above the Au bulk bands, along the directions of high-symmetry ΓX¯, XS¯, SY¯ and Y Γ¯ of the corresponding two-dimensional Brillouin zone. Measurements of the surface phonon dispersion branches can hence be made by different techniques such as helium atom scattering (HAS) to compare with. The calculated LDOS for Au and Pd atomic sites in the four top surface atomic layers span a wider range of frequencies than those for the individual Au(110) or Pd(110) metallic surfaces. These LDOS provide a spectral signature for the progressive transition from the surface dynamics to that of the Au crystal bulk. Knowledge of these LDOS for the surface alloy can also serve as an input for modeling the diffusion and reaction rates of chemical species at its surface.

  14. Design of a planar probe diagnostic system for plasmatron VISIONI and its application for the study of deuterium retention in W-Ta alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zayachuk, Y., E-mail: yzayachu@sckcen.be [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Department of Applied Physics, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium); Bousselin, G.; Schuurmans, J. [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Gasparyan, Yu. [National Research Nuclear University ' MEPhI' , Kashirskoe shosse 31, 115409 Moscow (Russian Federation); Uytdenhouwen, I. [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Van Oost, G. [Department of Applied Physics, Ghent University, Plateaustraat 22, 9000 Ghent (Belgium)

    2011-10-15

    One of the issues still to be clarified with respect to the possible use of tungsten and tungsten alloys as first wall material in fusion reactors is the retention of hydrogen isotopes under fusion-relevant conditions, such as the presence of helium ash, neutron irradiation, thermal shock. The low flux, high temperature plasma simulator VISIONI, being currently constructed at the Belgian nuclear research center SCK.CEN, will have the unique ability to handle radioactive materials - neutron irradiated samples and tritium plasma. Currently it is being tested with non-irradiated samples and deuterium plasma. To monitor the plasma parameters near the investigated specimen, a planar probe system has been developed. It was demonstrated that the plasmatron is able to provide conditions relevant for the ITER first wall. Investigations of deuterium retention in W-Ta alloys have been performed, using thermodesorption spectroscopy. A hypothesis of the existence of three kinds of trapping sites for deuterium in W-Ta alloys, based on deuterium release studies, is suggested.

  15. 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.)

  16. The addition of Si to the Ti–35Nb alloy and its effect on the corrosion resistance, when applied to biomedical materials

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, A.M.G.; Fernandes, B.S.; Souza, S.A.; Batista, W.W.; Cunha, F.G.C. [Department of Materials Science and Engineering, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Landers, R. [Institute of Physics Gleb Wataghin, State University of Campinas – UNICAMP, 13083-859 Campinas, SP (Brazil); Macedo, M.C.S.S., E-mail: michellecardinales@gmail.com [Department of Materials Science and Engineering, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil)

    2014-04-05

    Highlights: • An investigation of the corrosion resistance of Ti–Nb–Si was proposed. • The study was based on polarization curves, OCP, electrochemical impedance, XPS. • The addition of Si to 0.35% increased the corrosion resistance of the alloys. • Data suggest that the studied alloys are promising for biomedical applications. -- Abstract: Alloy elements such as niobium and silicon have been added to titanium as an alternative for new materials to be used in orthopedic implants once they present biocompatibility and favor reductions in the elastic modulus. However, these new materials’ behavior, in face of corrosion is still demanding careful investigations because they will be subjected to an aggressive environ, such as the human body. The corrosion resistance of the Ti–35Nb–(0; 0.15; 0.35; 0.55)Si (% in mass) when in physiological medium was assessed by means of polarization curves, open circuit potential and electrochemical impedance spectroscopy. The compositions of the passive films were analyzed by X-ray photoelectron spectroscopy (XPS). Outcomes show that the alloys presented good rapid repassivation capacity after film breaking under high potentials. The high values of resistance to polarization – Rp – pinpoint that the formed oxide films are resistive. They work as a protecting barrier against aggressive ions. Data suggest that the studied alloys are promising for orthopedic implant applications.

  17. The addition of Si to the Ti–35Nb alloy and its effect on the corrosion resistance, when applied to biomedical materials

    International Nuclear Information System (INIS)

    Highlights: • An investigation of the corrosion resistance of Ti–Nb–Si was proposed. • The study was based on polarization curves, OCP, electrochemical impedance, XPS. • The addition of Si to 0.35% increased the corrosion resistance of the alloys. • Data suggest that the studied alloys are promising for biomedical applications. -- Abstract: Alloy elements such as niobium and silicon have been added to titanium as an alternative for new materials to be used in orthopedic implants once they present biocompatibility and favor reductions in the elastic modulus. However, these new materials’ behavior, in face of corrosion is still demanding careful investigations because they will be subjected to an aggressive environ, such as the human body. The corrosion resistance of the Ti–35Nb–(0; 0.15; 0.35; 0.55)Si (% in mass) when in physiological medium was assessed by means of polarization curves, open circuit potential and electrochemical impedance spectroscopy. The compositions of the passive films were analyzed by X-ray photoelectron spectroscopy (XPS). Outcomes show that the alloys presented good rapid repassivation capacity after film breaking under high potentials. The high values of resistance to polarization – Rp – pinpoint that the formed oxide films are resistive. They work as a protecting barrier against aggressive ions. Data suggest that the studied alloys are promising for orthopedic implant applications

  18. Collaborative analysis for certification of zirconium and zirconium base alloy reference materials JAERI-Z11 to Z16

    International Nuclear Information System (INIS)

    The second Sub-Committee on Zircaloy Analysis was organized in April 1978, under the Committee on Analytical Chemistry on Nuclear Fuels and Reactor Materials, JAERI, for the renewal of zirconium and zirconium base alloy certified reference materials (CRMs). The Sub-Committee carried out collaborative analysis among 13 participating laboratories for the certification of the CRMs, JAERI-Z11 to Z18, after development, improvement and evaluation of analytical methods during the period of May 1978 to June 1982. As the result of the collaborative analysis, the certified value was given for 18 elements (Sn, Fe, Ni, Cr, B, Cd, U, Cu, Co, Mn, Pb, Al, Ti, Si, Mo, W, Hf, C) in the CRMs. The first part of this report includes general discussion, the second part principles of certification, the third part development and verification of analytical methods, and the fourth part evaluation of analytical results on 17 elements. Preparation of Z11 to Z18, and certification for carbon in JAERI-Z17 and Z18 were reported separately in JAERI-M 83-241 and M 83-035, respectively. (author)

  19. Synthesis of LiCoxNi1-xO2 cathode materials from electrolysis Co-Ni alloys

    Institute of Scientific and Technical Information of China (English)

    YE Mao; WEI Jin-ping; CAO Xiao-yan; ZHAI Jin-ling; WANG Xiao-yu; SUN Xin; YAN Jie

    2005-01-01

    The LiCoxNi1-xO2 (x-0.2, 0.5 and 0.8) cathode materials were synthesized by sintering the mixtures of lithium salt and Cox Ni1-x (OH)2 (x= 0.2, 0.5 and 0.8) which were achieved from corresponding Cox Ni1-x alloys by electrolysis technique. The structure and electrochemical characteristics of the obtained LiCoxNi1-xO2 were studied by XRD, SEM, PSCA and charge-discharge cycling test. The results show that the electrochemical capacities of the LiCoxNi1-xO2 (x=0.2, 0.5 and 0.8) materials are improved with the increase of the Ni content. The electrochemical performance of LiCo0.2 Ni0.8 O2 made in oxygen atmosphere has higher charge-discharge capacity and better cycleability compared with the one made in air atmosphere.

  20. Material composition and nuclear data libraries' influence on nickel-chromium alloys activation evaluation: a comparison with decay heat experiments

    CERN Document Server

    Cepraga, D G

    2000-01-01

    The paper presents the activation analyses on Inconel-600 nickel-chromium alloy. Three activation data libraries, namely the EAF-4.1, the EAF-97 and the FENDL/A-2, and the FENDL/D-2 decay data library, have been used to perform the calculation with the European activation code ANITA-4/M. The neutron flux distribution into the material samples was provided by JAERI as results of 3D Monte-Carlo MCNP transport code experiment simulation. A comparison with integral decay heat measurement performed at the Fusion Neutronics Source (FNS), JAERI, Tokai, Japan, is used to validate the computational approach. The calculation results are given and discussed. The impact of the material composition, including impurities, on the decay heat of samples irradiated in fusion-like neutron spectra is assessed and discussed. The discrepancies calculations-experiments are within the experimental errors, that is between 6% and 10%, except for the short cooling times (less than 40 min after the end of irradiation). To improve calcul...

  1. Effect of Wire-EDM cutting parameters on material removal rate of titanium alloy (Ti6Al4V)

    Science.gov (United States)

    Azam, N.; Afendi, M.

    2016-07-01

    In this study, titanium alloy (Ti6Al4V) which is also known as difficult to cut material is used as workpiece. Seven main parameters namely pulse duration (A), pulse interval (B), servo voltage (C), ignition pulse current (D), wire tension (E), wire speed (F) and dielectric pressure (G) have been experimentally studied by using Taguchi method as well as the determination of optimum parameters for material removal rate (MRR). Analysis of variance (ANOVA) has been used for recognizing the level of significant of WEDM cutting parameter for optimizing MRR and the result found that pulse duration and servo voltage give significant effect on MRR. While according to Signal to Noise (S/N) ratio response table for MRR, the parameters combination of A3B3C3D3E1F3G3 give the optimum value for MRR. It is also observed that the predicted results agree with the experimental values within an error of 4.6 %.

  2. Estimation of Material Parameters in Nonlinear Hardening Plasticity Models and Strain Life Curves for CuAg Alloy

    Science.gov (United States)

    Srnec Novak, J.; Benasciutti, D.; De Bona, F.; Stanojević, A.; De Luca, A.; Raffaglio, Y.

    2016-03-01

    This work investigates the cyclic response and low-cycle fatigue behaviour of a CuAg alloy used in crystallizer for continuous casting lines. Therefore isothermal strain-based fatigue tests are first performed on CuAg specimens at different temperature levels (20 °C, 250 °C, 300 °C). The evolution of stress-strain loops recorded during the cyclic tests is used for the parameter identification of several nonlinear hardening models (nonlinear kinematic, nonlinear isotropic). Cyclic stress-strain data from experiments are compared with results from numerical simulations with the identified material parameters, showing a satisfying agreement. Critical examination of numerical results from different models is also performed. Finally, the strain- life fatigue curves estimated from experimental data are compared with approximate strain-life equations (Universal Slopes Equation, 10% Rule) which are obtained from simple tensile tests. The material parameters determined in this work can conveniently be used as inputs in a elasto- plastic finite element simulations of a crystallizer.

  3. Synthesis And Electrochemical Characteristics Of Mechanically Alloyed Anode Materials SnS2 For Li/SnS2 Cells

    Directory of Open Access Journals (Sweden)

    Hong J.H.

    2015-06-01

    Full Text Available With the increasing demand for efficient and economic energy storage, tin disulfide (SnS2, as one of the most attractive anode candidates for the next generation high-energy rechargeable Li-ion battery, have been paid more and more attention because of its high theoretical energy density and cost effectiveness. In this study, a new, simple and effective process, mechanical alloying (MA, has been developed for preparing fine anode material tin disulfides, in which ammonium chloride (AC, referred to as process control agents (PCAs, were used to prevent excessive cold-welding and accelerate the synthesis rates to some extent. Meanwhile, in order to decrease the mean size of SnS2 powder particles and improve the contact areas between the active materials, wet milling process was also conducted with normal hexane (NH as a solvent PCA. The prepared powders were both characterized by X-ray diffraction, Field emission-scanning electron microscopeand particle size analyzer. Finally, electrochemical measurements for Li/SnS2 cells were takenat room temperature, using a two-electrode cell assembled in an argon-filled glove box and the electrolyte of 1M LiPF6 in a mixture of ethylene carbonate(EC/dimethylcarbonate (DMC/ethylene methyl carbonate (EMC (volume ratio of 1:1:1.

  4. Creep Behavior of High Temperature Alloys for Generation IV Nuclear Energy Systems

    Science.gov (United States)

    Wen, Xingshuo

    The Very High Temperature Reactor (VHTR) is one of the leading concepts of the Generation IV nuclear reactor development, which is the core component of Next Generation Nuclear Plant (NGNP). The major challenge in the research and development of NGNP is the performance and reliability of structure materials at high temperature. Alloy 617, with an exceptional combination of high temperature strength and oxidation resistance, has been selected as a primary candidate material for structural use, particularly in Intermediate Heat Exchanger (IHX) which has an outlet temperature in the range of 850 to 950°C and an inner pressure from 5 to 20MPa. In order to qualify the material to be used at the operation condition for a designed service life of 60 years, a comprehensive scientific understanding of creep behavior at high temperature and low stress regime is necessary. In addition, the creep mechanism and the impact factors such as precipitates, grain size, and grain boundary characters need to be evaluated for the purpose of alloy design and development. In this study, thermomechanically processed specimens of alloy 617 with different grain sizes were fabricated, and creep tests with a systematic test matrix covering the temperatures of 850 to 1050°C and stress levels from 5 to 100MPa were conducted. Creep data was analyzed, and the creep curves were found to be unconventional without a well-defined steady-state creep. Very good linear relationships were determined for minimum creep rate versus stress levels with the stress exponents determined around 3-5 depending on the grain size and test condition. Activation energies were also calculated for different stress levels, and the values are close to 400kJ/mol, which is higher than that for self-diffusion in nickel. Power law dislocation climb-glide mechanism was proposed as the dominant creep mechanism in the test condition regime. Dynamic recrystallization happening at high strain range enhanced dislocation climb and

  5. Radioactive materials system of the ININ (SMATRAD)

    International Nuclear Information System (INIS)

    The radioactive iodine (I-131) it is an isotope created starting from the iodine with the purpose of emitting radiation for medicinal use. When a small dose of I-131 is ingested, this is absorbed in the sanguine torrent in the gastrointestinal tract (Gl) and it is concentrated by the blood on the thyroid gland, where it begins to destroy the cells. This treatment makes that the activity of the thyroid decreases in great measure and in some cases it can transform an hyperactive thyroid in a hypoactive thyroid which requires additional treatments. The sodium iodide I-131 is one of the products elaborated and marketed by the ININ in the Radiopharmaceuticals and Radioisotopes production plant, dependent of the Radioactive Material Department of the Nuclear Applications in the Health Management. The Plant is the only one in its type that exists in the country, it has Sanitary License and Good Practice of Production Certificate, emitted by the Secretary of Health, and licenses for the handling and the transportation of radioactive material, sent by the National Commission of Nuclear Safety and Safeguards. Also, the quality system of the plant is certified under the ISO 9001:2000 standard. (Author)

  6. Advanced materials for thermal protection system

    Science.gov (United States)

    Heng, Sangvavann; Sherman, Andrew J.

    1996-03-01

    Reticulated open-cell ceramic foams (both vitreous carbon and silicon carbide) and ceramic composites (SiC-based, both monolithic and fiber-reinforced) were evaluated as candidate materials for use in a heat shield sandwich panel design as an advanced thermal protection system (TPS) for unmanned single-use hypersonic reentry vehicles. These materials were fabricated by chemical vapor deposition/infiltration (CVD/CVI) and evaluated extensively for their mechanical, thermal, and erosion/ablation performance. In the TPS, the ceramic foams were used as a structural core providing thermal insulation and mechanical load distribution, while the ceramic composites were used as facesheets providing resistance to aerodynamic, shear, and erosive forces. Tensile, compressive, and shear strength, elastic and shear modulus, fracture toughness, Poisson's ratio, and thermal conductivity were measured for the ceramic foams, while arcjet testing was conducted on the ceramic composites at heat flux levels up to 5.90 MW/m2 (520 Btu/ft2ṡsec). Two prototype test articles were fabricated and subjected to arcjet testing at heat flux levels of 1.70-3.40 MW/m2 (150-300 Btu/ft2ṡsec) under simulated reentry trajectories.

  7. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  8. Material control system simulator user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Hollstien, R.B.

    1978-01-24

    This report describes the use of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts.

  9. Phase equilibria in the Ni-Co-Ga alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Ducher, R. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan); Kainuma, R. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Sendai 980-8577 (Japan)], E-mail: kainuma@tagen.tohoku.ac.jp; Ishida, K. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan)

    2008-10-20

    Phase equilibria among the {alpha} (A1), {alpha}' (L1{sub 2}), {beta} (B2), {delta} (Ni{sub 5}Ga{sub 3}) and {epsilon} (Ni{sub 13}Ga{sub 9}) phases at elevated temperatures and the existing composition region of the martensite phase at room temperature in the Ni-Co side of the Ni-Co-Ga system were examined by electron probe microanalysis (EPMA) using diffusion triples which were fabricated by two-step diffusion coupling. It was confirmed that single-phase regions of the {alpha}, {alpha}' and {beta} phases at 700 and 1000 deg. C exist in a wide composition range parallel to Ni-Co section and that the existing region of the martensite phase at room temperature is also located over a wide range in the {beta} phase along the {beta} + {alpha} (or {alpha}') two-phase region.

  10. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle

  11. Phase equilibria in the Ni-Fe-Ga alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Ducher, R. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan); Kainuma, R. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Sendai 980-8577 (Japan)], E-mail: kainuma@tagen.tohoku.ac.jp; Ishida, K. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan)

    2008-09-08

    The phase equilibria, A2/B2 and B2/L2{sub 1} (or D0{sub 3}) order-disorder transitions and martensitic transformation on the Ni-Fe side of the Ni-Fe-Ga system were examined by electron probe microanalysis (EPMA) and differential scanning calorimetric (DSC) measurement. The equilibrium compositions of interrelations mainly among the {alpha} (A2), {beta} (B2), {beta}' (L2{sub 1} or D0{sub 3}), {gamma} (A1) and {gamma}' (L1{sub 2}) phases were determined using diffusion triples which were fabricated by two-step diffusion coupling. It was confirmed that a bcc single-phase region composed of {alpha}, {beta} and {beta}' at 850-1000 deg. C exists in a wide composition range and that the critical temperature of the B2/L2{sub 1} order-disorder transformation in the Fe{sub 3}Ga-Ni{sub 3}Ga pseudo-binary section gradually increases with increasing Ni content. The existing composition region of the martensite phase at room temperature was also determined by the diffusion triple method.

  12. Thermodynamics of multicaloric effects in multiferroic materials: application to metamagnetic shape-memory alloys and ferrotoroidics.

    Science.gov (United States)

    Planes, Antoni; Castán, Teresa; Saxena, Avadh

    2016-08-13

    We develop a general thermodynamic framework to investigate multicaloric effects in multiferroic materials. This is applied to the study of both magnetostructural and magnetoelectric multiferroics. Landau models with appropriate interplay between the corresponding ferroic properties (order parameters) are proposed for metamagnetic shape-memory and ferrotoroidic materials, which, respectively, belong to the two classes of multiferroics. For each ferroic property, caloric effects are quantified by the isothermal entropy change induced by the application of the corresponding thermodynamically conjugated field. The multicaloric effect is obtained as a function of the two relevant applied fields in each class of multiferroics. It is further shown that multicaloric effects comprise the corresponding contributions from caloric effects associated with each ferroic property and the cross-contribution arising from the interplay between these ferroic properties.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'. PMID:27402925

  13. Selection of materials for tokamak plasma facing elements based on a liquid tin capillary pore system

    Science.gov (United States)

    Lyublinski, I. E.; Vertkov, A. V.; Zharkov, M. Yu; Sevryukov, O. N.; Dzhumaev, P. S.; Shumskiy, V. A.; Ivannikov, A. A.

    2016-09-01

    Capillary-Pore Systems (CPS) filled by liquid metals are considered as an alternative solution of materials choice for plasma facing component of tokamak reactor. Tin is viewed as one of the candidates for CPS because it has lower corrosiveness than gallium and lower saturated vapour pressure compared to lithium. The corrosion resistance of Mo, Nb and W in pure liquid tin was investigated. The corrosion tests were carried out in the static isothermal conditions at a temperature up to 1050°C. As a result of the corrosion study, it was found that Mo does not corrode in liquid Sn, as opposed to Nb and is compatible with liquid tin in temperatures of up to approx. 1000°C. This allows considering Mo as an alloy base material of the in-vessel tokamak elements based on liquid tin capillary pore systems.

  14. Evaluation of single liquid primers with organic sulfur compound for bonding between indirect composite material and silver-palladium-copper-gold alloy.

    Science.gov (United States)

    Shimoe, Saiji; Tanoue, Naomi; Satoda, Takahiro; Murayama, Takeshi; Nikawa, Hiroki; Matsumura, Hideo

    2010-01-01

    The purpose of this study was to evaluate the effect of primers on bonding between a silver-palladium-copper-gold alloy and an indirect composite material. Cast disks were air-abraded with alumina, conditioned with one of five primers (Alloy Primer, Luna-Wing Primer, Metal Primer II, Metaltite, M.L. Primer), and bonded with a light-activated indirect composite. Shear bond strengths were determined after 20,000 times of thermocycling. The results showed that four of the primers, except the Luna-Wing Primer, were effective in enhancing the bond strength as compared with the unprimed control group. Of these four primers, Alloy Primer, Metal Primer II, and M.L. Primer exhibited significantly greater bond strengths. It can be concluded that the effectiveness of primers varies considerably according to the organic sulfur compounds added to the solvent, and that care must be taken in selecting priming agents for bonding the composite material and the silver-palladium-copper-gold alloy.

  15. Geothermal systems materials: a workshop/symposium

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    Sixteen papers are included. A separate abstract was prepared for each. Summaries of workshops on the following topics are also included in the report: non-metallic materials, corrosion, materials selection, fluid chemistry, and failure analysis. (MHR)

  16. Development of Advanced Alloys using Fullerenes

    Science.gov (United States)

    Sims, J.; Wasz, M.; O'Brien, J.; Callahan, D. L.; Barrera, E. V.

    1994-01-01

    Development of advanced alloys using fullerenes is currently underway to produce materials for use in the extravehicular mobility unit (EMU). These materials will be directed toward commercial usages as they are continually developed. Fullerenes (of which the most common is C(sub 60)) are lightweight, nanometer size, hollow molecules of carbon which can be dispersed in conventional alloy systems to enhance strength and reduce weight. In this research, fullerene interaction with aluminum is investigated and a fullerene-reinforced aluminum alloy is being developed for possible use on the EMU. The samples were manufactured using standard commercial approaches including powder metallurgy and casting. Alloys have been processed having 1.3, 4.0 and 8.0 volume fractions of fullerenes. It has been observed that fullerene dispersion is related to the processing approach and that they are stable for the processing conditions used in this research. Emphasis will be given to differential thermal analysis and wavelength dispersive analysis of the processed alloys. These two techniques are particularly useful in determining the condition of the fullerenes during and after processing. Some discussion will be given as to electrical properties of fullerene-reinforced materials. Although the aluminum and other advanced alloys with fullerenes are being developed for NASA and the EMU, the properties of these materials will be of interest for commercial applications where specific Dual-Use will be given.

  17. Calculation of the self-formation driving force for composite microstructure in liquid immiscible alloy system

    Institute of Scientific and Technical Information of China (English)

    LIU Xingjun; WANG Cuiping; Ikuo OHNUMA; Ryosuke KAINUMA; Kiyohito ISHIDA; CHEN Xiaohu

    2005-01-01

    Using Becker's method, we calculate the interfacial energy between two liquid phases in an immiscible system. Based on the Gibbs-Thomson equation, the force acting on the droplet towards the thermal center can be obtained by integrating the interfacial energy between the droplet and matrix liquid phase, which is related to both the radius of a droplet and the temperature gradient. In addition, the forces of gravitation and buoyancy also act on the droplet. The calculated results indicate that the resultant for these forces together mainly decides the microstructure morphology of the solidified alloy. The calculated results are in good agreement with the corresponding experimental results.

  18. Materials properties numerical database system established and operational at CINDAS/Purdue University

    Science.gov (United States)

    Ho, C. Y.; Li, H. H.

    1989-01-01

    A computerized comprehensive numerical database system on the mechanical, thermophysical, electronic, electrical, magnetic, optical, and other properties of various types of technologically important materials such as metals, alloys, composites, dielectrics, polymers, and ceramics has been established and operational at the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) of Purdue University. This is an on-line, interactive, menu-driven, user-friendly database system. Users can easily search, retrieve, and manipulate the data from the database system without learning special query language, special commands, standardized names of materials, properties, variables, etc. It enables both the direct mode of search/retrieval of data for specified materials, properties, independent variables, etc., and the inverted mode of search/retrieval of candidate materials that meet a set of specified requirements (which is the computer-aided materials selection). It enables also tabular and graphical displays and on-line data manipulations such as units conversion, variables transformation, statistical analysis, etc., of the retrieved data. The development, content, accessibility, etc., of the database system are presented and discussed.

  19. The Eighth International Ural Seminar Radiation damage physics of metals and alloys. Abstracts

    International Nuclear Information System (INIS)

    The book includes abstracts of the Eight International Ural Seminar Radiation damage physics of metals and alloys (Snezhinsk, 23 February - 1 March, 2009). Reports on the characteristics of point defects in different alloys and compounds including Fe-Cr(Ni) systems are presented. Effects of irradiation and strong deformation on changing microstructure and properties of metals and alloys are discussed. Gaseous impurities in irradiated metals and alloys, materials problems in nuclear and thermonuclear powers, physical properties and atomic defects in actinides and actinide alloys, and model analogs are discussed. Reports on physics of radiation effects in magnetics, superconductors, semiconductors and nonconductors, as well as technology and experimental technique, ion implantation are performed

  20. Metallurgical and chemical characterization of copper alloy reference materials within laser ablation inductively coupled plasma mass spectrometry: Method development for minimally-invasive analysis of ancient bronze objects

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian, E-mail: damian.walaszek@empa.ch [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Senn, Marianne [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Philippe, Laetitia [Laboratory for Mechanics of Materials and Nanostructures, Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkstrasse 39, CH-3602 Thun (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2013-01-01

    The chemical composition of ancient metal objects provides important information for manufacturing studies and authenticity verification of ancient copper or bronze artifacts. Non- or minimal-destructive analytical methods are preferred to mitigate visible damage. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) enables the determination of major elements as well as impurities down to lower ppm-levels, however, accuracy and precision of analysis strongly depend on the homogeneity of reference materials used for calibration. Moreover, appropriate analytical procedures are required e.g. in terms of ablation strategies (scan mode, spot size, etc.). This study reviews available copper alloy (certified) reference materials — (C)RMs from different sources and contributes new metallurgical data on homogeneity and spatial elemental distribution. Investigations of the standards were performed by optical and scanning electron microscopy with X-ray spectrometry (SEM-EDX) for the following copper alloy and bronze (certified) reference materials: NIST 454, BAM 374, BAM 211, BAM 227, BAM 374, BAM 378, BAS 50.01-2, BAS 50.03-4, and BAS 50.04-4. Additionally, the influence of inhomogeneities on different ablation and calibration strategies is evaluated to define an optimum analytical strategy in terms of line scan versus single spot ablation, variation of spot size, selection of the most appropriate RMs or minimum number of calibration reference materials. - Highlights: ► New metallographic data for copper alloy reference materials are provided. ► Influence of RMs homogeneity on quality of LA-ICPMS analysis was evaluated. ► Ablation and calibration strategies were critically discussed. ► An LA-ICPMS method is proposed for analyzing most typical ancient copper alloys.

  1. Pengaruh Penambahan Ni, Cu, dan Al dan Waktu Milling pada Mechanical Alloying Terhadap Sifat Absorpsi dan Desorpsi Mg sebagai Material Penyimpan Hidrogen

    Directory of Open Access Journals (Sweden)

    Febrian Budi Pratama

    2012-09-01

    Full Text Available Mg merupakan salah satu material yang digunakan sebagai material penyimpan hidrogen dengan membentuk MgH2. Sifat absorpsi dan desorpsi hidrogen dari suatu metal hidrida salah satunya tergantung  pada bahan, unsur penambah, dan metode pembuatannya. Pada penelitian kali ini Mg sebagai material penyimpan hidrogen dihasilkan melalui metode mechanical alloying dengan unsur penambah Ni, Cu, dan Al dan variasi waktu milling 10, 20, 30 jam. Selanjutnya sampel dilakukan pengujian SEM, XRD, DSC, dan Uji hidrogenisasi. Dari data uji diperoleh bahwa meningkatnya waktu milling menurunkan ukuran partikel sehingga meningkatkan wt% hidrogen terabsorb dan menurunkan temperatur onset desorpsi. Namun efek aglomerasi dan coldwelding yang berlebih pada proses mechanical alloying mengakibatkan ukuran partikel menjadi lebih besar. Unsur pemadu Al dan Cu berfungsi sebagai katalis, sedangkan Ni berfungsi sebagai pemadu yang ikut bereaksi dengan hidrogen. Mg10wt%Al dengan waktu milling 20 jam mempunyai nilai weight percent terbaik H2 yaitu 0.38% dalam temperatur hidrogenisasi 2500C, tekanan 3 atm, dan waktu tahan 1 jam. Sedangkan Mg10wt%Al dengan waktu milling 30 jam memiliki temperatur onset paling rendah yaitu 341.490C Kata Kunci— Absorpsi, Desorpsi, Material Penyimpan Hidrogen, Mechanical Alloying, Mg

  2. 锂离子电池合金负极材料的应用研究%Application study of silicon alloy material for Li-ion battery

    Institute of Scientific and Technical Information of China (English)

    冼海燕; 廖立勇; 许瑞; 赵丰刚

    2012-01-01

    合金材料是目前锂电行业研究较热的一款高能量密度的负极材料.但由于循环过程中极片体积膨胀及循环性能差等问题未得到广泛应用.主要是针对硅碳合金材料的应用进行研究,从工艺方面进行调整优化来改善合金材料在锂离子电池中存在的问题.%Alloy material is one of the anode materials with high energy density, which is popularly researched in lithium-ion battery. However, it is not widely used in commercial Li-ion battery because of swelling during the cycle and poor cyclic performance. The application of silicon-carbon alloy material by the adjustment and optimization of process was focused to solve the problems that existed in alloy material based Li-ion battery.

  3. Final Report Designing Biomimetic, Dissipative Material Systems

    Energy Technology Data Exchange (ETDEWEB)

    Balazs, Anna C.

    2016-01-21

    Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.

  4. Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Chu, P K; Chung, C Y; Liu, X Y; Lu, W W; Chan, D; Chan, S C W; Luk, K D K; Cheung, K M C

    2007-08-01

    Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants.

  5. Comparison of Shear Bond Strengths of three resin systems for a Base Metal Alloy bonded to

    Directory of Open Access Journals (Sweden)

    Jlali H

    1999-12-01

    Full Text Available Resin-bonded fixed partial dentures (F.P.D can be used for conservative treatment of partially edentulous"npatients. There are numerous studies regarding the strength of resin composite bond to base meta! alloys. Shear bond"nstrength of three resin systems were invistigated. In this study these systems consisted of: Panavia Ex, Mirage FLC and"nMarathon V. Thirty base metal specimens were prepared from rexillium III alloy and divided into three groups. Then each"ngroup was bonded to enamel of human extracted molar teeth with these systems. All of specimens were stored in water at"n37ac for 48 hours. A shear force was applied to each specimen by the instron universal testing machine. A statistical"nevaluation of the data using one-way analysis of variance showed that there was highly significant difference (P<0.01"nbetween the bond strengths of these three groups."nThe base metal specimens bonded with panavia Ex luting agent, exhibited the highest mean bond strength. Shear bond"nstrength of the specimens bonded to enamel with Mirage F1C showed lower bond strenght than panavia EX. However, the"nlowest bond strength was obtained by the specimens bonded with Marathon V.

  6. Numerical Simulation of Temperature Distribution and Material Flow During Friction Stir Welding 2017A Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    MimouniOussama

    2016-01-01

    Full Text Available This study describes the use of fluid dynamic code, FLUENT to model the flow of metal in the AA2017A case around the welding tool pin (FSW. A standard threaded tool profile is used for the analysis of phenomena during welding such as heat generation and flow of the material are included. The main objective is to gain a better understanding of the flow of material around a tool. The model showed a large number of phenomena similar to those of the real process. The model has also generated a sufficient amount of heat, which leads to a good estimate of the junction temperature. These results were obtained using a viscosity which is near the solidus softening.

  7. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  8. Corrosion of copper-alloy tubes in the NPP cooling systems

    International Nuclear Information System (INIS)

    Factors efficiency on leaks in the NPP power unit steam turbine condensers are analyzed. Causes of corrosion - erosion wear of copper-alloy tubes are considered. A model for calculation of copper and copper-nickel alloy corrosion is proposed

  9. Evaluation of Al and Some of Its Alloys as Anode Materials vs γ-MnO2 as Cathode Material and Ore Produced γ-MnO2 vs Zn Anode in KOH Solution

    Institute of Scientific and Technical Information of China (English)

    A.M.A.Hashem; Kh.S. Abou-El-Sherbini; S. Zein El Abedin; H. Abbas

    2006-01-01

    In this study electrochemical performance of Al and some of its alloys (Al-Zn, Al-Mg and Al-Mn) anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn>Al-Mg>Al>Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy (SEM). SEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure.Electrolytic manganese dioxide (EMD) produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore (β-MnO2) by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample (EMD1) was performed well in comparison with EMD standard (EMD2) (commercial battery grade electrolytic manganese dioxide, TOSOH-Hellas GH-S). SEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

  10. Centrifugal casting processes of manufacturing in situ functionally gradient composite materials of Al-19Si-5Mg alloy

    Institute of Scientific and Technical Information of China (English)

    XIE Yong; LIU Changming; ZHAI Yanbo; WANG Kai; LING Xuedong

    2009-01-01

    Cylindrical components of in situ functionally gradient composite materials of Al-19Si-5Mg alloy were manufactured by centrifugal casting. Microstructure characteristics of the manufactured components were observed and the effects of the used process factors on these character-istics were analyzed. The results of observations shows that, in thickness, the components possess microstructures accumulating lots of Mg2Si particles and a portion of primary silicon particles in the inner layer, a little Mg2Si and primary silicon particles in the outer layer, and without any Mg2Si and primary silicon particle in the middle layer. The results of the analysis indicate that the rotation rate of centrifugal casting, mould temperature, and melt pouring temperature have evidently affected the accumulation of the second phase particles. Also, the higher the centrifugal rotation rate, mould temperature, and melt pouring temperature are, the more evident in the inner layer the degree of accumulation of Mg2Si and primary silicon particles is.

  11. Slurry wear characteristics of zinc-based alloys: Effects of sand content of slurry, silicon addition to alloy system and traversal distance

    Institute of Scientific and Technical Information of China (English)

    B.K. PRASAD; O.P. MODI

    2009-01-01

    This investigation deals with the observations pertaining to the effects of specimen and slurry compositions as well as traversal distance on the slurry wear response of a zinc-based alloy. The composition of the alloy was altered by adding 4% silicon to it. The slurry composition was varied through changing the concentration of the sand particles in the range of 0-60% that were suspended in the (liquid) electrolyte. The electrolyte contained 4 g sodium chloride and 5 mL concentrated sulphuric acid dissolved in 10 L of water. The slurry wear tests were conducted at a speed of 7.02 m/s over the traversal distance range of 15-500 km. The wear rate increased initially with traversal distance, attained a maximum and decreased thereafter irrespective of the specimen and test environment. However, the wear rate peaks were less prominent in the liquid plus sand environments than the liquid-only medium. Further, the wear rate peak in the liquid-only medium appeared at a shorter traversal distance than the one in the sand containing slurries. Addition of sand particles to the electrolyte reduced the wear rate of the samples to 5%-15% depending on the sand concentration of the slurry. Moreover, intermediate (40%) sand content led to a maximum wear rate when compared with in the liquid plus sand media. However, this maximum was still less than in the liquid-only medium. The silicon containing alloy suffered from higher wear rates than the silicon free alloy samples when tested in the liquid-only medium. On the contrary, the trend reversed in liquid plus 20% and 40% sand environments whereas a mixed response was noted in the slurry containing 60% sand. In the latter case, the presence of silicon proved deleterious initially while an opposite trend was observed at longer traversal distances. The wear response of the samples was discussed in terms of specific features of their microconstituents like silicon and the predominant material removal mechanism in a given set of

  12. Materials science for solar energy conversion systems

    CERN Document Server

    Granqvist, CG

    1991-01-01

    Rapid advances in materials technology are creating many novel forms of coatings for energy efficient applications in solar energy. Insulating heat mirrors, selective absorbers, transparent insulation and fluorescent concentrators are already available commercially. Radiative cooling, electrochromic windows and polymeric light pipes hold promise for future development, while chemical and photochemical processes are being considered for energy storage. This book investigates new material advances as well as applications, costs, reliability and industrial production of existing materials. Each c

  13. Experimental investigation on the effects of cooling system on surface quality in high speed milling of an aluminium alloy

    Science.gov (United States)

    Chirita, B.; Tampu, N. C.; Brabie, G.; Radu, M. C.

    2016-08-01

    Surface quality is often an important feature of industrial products, not only from the impact it has on the aesthetic aspect but also for the functional role of the parts. High quality surface increases corrosion resistance, assures a longer life cycle for the product and lowers the wear. For a machined part, surface quality is influenced by a series of factors such as the material of the part, the process type, tool geometry, cutting parameters or the cooling system. The choice of the cooling system is especially important, taking into account that the proper conditions will not only assure a superior surface quality, but will also lower the costs and reduce the environmental impact and health risks. The present study aims to investigate the performance of the cooling system and the effect of the cutting parameters on the characteristics of the surfaces resulted from high speed face milling of some parts made of Al 7050-T7451 aluminium alloy. Dry cutting conditions and minimum quantity lubrication (MQL) where used. The results were analysed using analysis of variance (ANOVA).

  14. Optimization of Electrode Material for EDM Die-sinking of Titanium Alloy Grade 5 - Ti6Al4V

    Directory of Open Access Journals (Sweden)

    Sangeeth Suresh

    2016-08-01

    Full Text Available Titanium alloy grade 5, Ti6Al4V, is extensively gaining importance in the industrial environment, specifically in aerospace, medical and automotive domains, mainly due to its exceptional blend of mechanical properties like high hardness which is further heat treatable, high strength-to-weight ratio which makes it light, high corrosion and temperature resistance etc. However, the same properties undervalue Ti6Al4V as a conventionally difficult-to-machine material. Rapid tool wear, excessive heat generation, dimensional instability and loss of surface integrity are the issues that plague the conventional machining of Ti6Al4V.  In view of these facts, non-traditional machining processes like electron discharge machining (EDM - die sinking and wire cut prove to be a substitute for the conventional machining. In this study, an experimental optimization of EDM die-sinking electrode materials among copper, brass and graphite, is carried out. Experimental design is created using a statistical tool and actual machining is carried out to record the surface roughness, variations on the surface hardness and dimensional stability. Quality evaluation and statistical analysis substantiates graphite electrodes to produce better surface finish-Ra 2.05microns with minimal dimensional variation-less than 10%-when operated at minimum spark gaps. It is inferred that graphite electrodes exhibit higher resistivity towards current than its counterparts thus passing minimum spark energy preventing excessive self-wear and a dimensionally accurate workpiece. The depth of machining highly impacts the variations on the surface hardness post machining.

  15. Heavy Vehicle Propulsion System Materials Program semiannual progress report for October 1996 through March 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks. The design of advanced components for high-efficiency diesel engines has, in some cases, pushed the performance envelope for materials of construction past the point of reliable operation. Higher mechanical and tribological stresses and higher temperatures of advanced designs limit the engine designers; advanced materials allow the design of components that may operate reliably at higher stresses and temperatures, thus enabling more efficient engine designs. Advanced materials also offer the opportunity to improve the emissions, NVH, and performance of diesel engines for pickup trucks, vans, and sport utility vehicles. The principal areas of research are: (1) cost effective high performance materials and processing; (2) advanced manufacturing technology; (3) testing and characterization; and (4) materials and testing standards.

  16. High-speed blanking of copper alloy sheets: Material modeling and simulation

    Science.gov (United States)

    Husson, Ch.; Ahzi, S.; Daridon, L.

    2006-08-01

    To optimize the blanking process of thin copper sheets ( ≈ 1. mm thickness), it is necessary to study the influence of the process parameters such as the punch-die clearance and the wear of the punch and the die. For high stroke rates, the strain rate developed in the work-piece can be very high. Therefore, the material modeling must include the dynamic effects.For the modeling part, we propose an elastic-viscoplastic material model combined with a non-linear isotropic damage evolution law based on the theory of the continuum damage mechanics. Our proposed modeling is valid for a wide range of strain rates and temperatures. Finite Element simulations, using the commercial code ABAQUS/Explicit, of the blanking process are then conducted and the results are compared to the experimental investigations. The predicted cut edge of the blanked part and the punch-force displacement curves are discussed as function of the process parameters. The evolution of the shape errors (roll-over depth, fracture depth, shearing depth, and burr formation) as function of the punch-die clearance, the punch and the die wear, and the contact punch/die/blank-holder are presented. A discussion on the different stages of the blanking process as function of the processing parameters is given. The predicted results of the blanking dependence on strain-rate and temperature using our modeling are presented (for the plasticity and damage). The comparison our model results with the experimental ones shows a good agreement.

  17. Exploration of CIGAS Alloy System for Thin-Film Photovoltaics on Novel Lightweight and Flexible Substrates

    Science.gov (United States)

    Woods, Lawrence M.; Kalla, Ajay; Ribelin, Rosine

    2007-01-01

    Thin-film photovoltaics (TFPV) on lightweight and flexible substrates offer the potential for very high solar array specific power (W/kg). ITN Energy Systems, Inc. (ITN) is developing flexible TFPV blanket technology that has potential for specific power greater than 2000 W/kg (including space coatings) that could result in solar array specific power between 150 and 500 W/kg, depending on array size, when mated with mechanical support structures specifically designed to take advantage of the lightweight and flexible substrates.(1) This level of specific power would far exceed the current state of the art for spacecraft PV power generation, and meet the needs for future spacecraft missions.(2) Furthermore the high specific power would also enable unmanned aircraft applications and balloon or high-altitude airship (HAA) applications, in addition to modular and quick deploying tents for surface assets or lunar base power, as a result of the high power density (W/sq m) and ability to be integrated into the balloon, HAA or tent fabric. ITN plans to achieve the high specific power by developing single-junction and two-terminal monolithic tandem-junction PV cells using thin-films of high-efficiency and radiation resistant CuInSe2 (CIS) partnered with bandgap-tunable CIS-alloys with Ga (CIGS) or Al (CIAS) on novel lightweight and flexible substrates. Of the various thin-film technologies, single-junction and radiation resistant CIS and associated alloys with gallium, aluminum and sulfur have achieved the highest levels of TFPV device performance, with the best efficiency reaching 19.5% under AM1.5 illumination conditions and on thick glass substrates.(3) Thus, it is anticipated that single- and tandem-junction devices with flexible substrates and based on CIS and related alloys will achieve the highest levels of thin-film space and HAA solar array performance.

  18. Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

    Directory of Open Access Journals (Sweden)

    Christoph Rehbock

    2014-09-01

    Full Text Available Due to the abundance of nanomaterials in medical devices and everyday products, toxicological effects related to nanoparticles released from these materials, e.g., by mechanical wear, are a growing matter of concern. Unfortunately, appropriate nanoparticles required for systematic toxicological evaluation of these materials are still lacking. Here, the ubiquitous presence of surface ligands, remaining from chemical synthesis are a major drawback as these organic residues may cause cross-contaminations in toxicological studies. Nanoparticles synthesized by pulsed laser ablation in liquid are a promising alternative as this synthesis route provides totally ligand-free nanoparticles. The first part of this article reviews recent methods that allow the size control of laser-fabricated nanoparticles, focusing on laser post irradiation, delayed bioconjugation and in situ size quenching by low salinity electrolytes. Subsequent or parallel applications of these methods enable precise tuning of the particle diameters in a regime from 4–400 nm without utilization of any artificial surface ligands. The second paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes, mammalian cells and bacteria are considered.

  19. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST). Research on Materials for the High Speed Civil Transport

    Science.gov (United States)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    Since 1986, the NASA-Langley Research Center has sponsored the NASA-UVa Light Alloy and Structures Technology (LA2ST) Program at the University of Virginia (UVa). The fundamental objective of the LA2ST program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures. The LA2ST program has aimed to product relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The scope of the LA2ST Program is broad. Research areas include: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals and Composites, (2) Aerospace Materials Science, (3) Mechanics of materials for Aerospace Structures, and (4) Thermal Gradient Structures. A substantial series of semi-annual progress reports issued since 1987 documents the technical objectives, experimental or analytical procedures, and detailed results of graduate student research in these topical areas.

  20. Computerized nuclear material system at Sandia National Laboratories

    International Nuclear Information System (INIS)

    SNLA developed and implemented a nuclear material control and accountability system on an HP 3000 minicomputer. The Sandia Nuclear Materials Computer System (SNMCS) which became operative in January 1980 provides: control of shipments and receivals of nuclear material, control of internal transfers of nuclear material, automated inventory with a bar code system, control of inventory adjustments, automated reporting/transmitting to other contractors and operations offices, automated ledgers and journals for material weights and costs, and interface to the Albuquerque Operations Office (ALO) Automated 741 System

  1. The activity of nanocrystalline Fe-based alloys as electrode materials for the hydrogen evolution reaction

    Science.gov (United States)

    Müller, Christian Immanuel; Sellschopp, Kai; Tegel, Marcus; Rauscher, Thomas; Kieback, Bernd; Röntzsch, Lars

    2016-02-01

    In view of alkaline water electrolysis, the activities for the hydrogen evolution reaction of nanocrystalline Fe-based electrode materials were investigated and compared with the activities of polycrystalline Fe and Ni. Electrochemical methods were used to elucidate the overpotential value, the charge transfer resistance and the double layer capacity. Structural properties of the electrode surface were determined with SEM, XRD and XPS analyses. Thus, a correlation between electrochemical and structural parameters was found. In this context, we report on a cyclic voltammetric activation procedure which causes a significant increase of the surface area of Fe-based electrodes leading to a boost in effective activity of the activated electrodes. It was found that the intrinsic activity of activated Fe-based electrodes is very high due to the formation of a nanocrystalline surface layer. In contrast, the activation procedure influences only the intrinsic activity of the Ni electrodes without the formation of a porous surface layer.

  2. Alloying design of oxide dispersion strengthened ferritic steel for long life FBRs core materials

    Science.gov (United States)

    Ukai, S.; Harada, M.; Okada, H.; Inoue, M.; Nomura, S.; Shikakura, S.; Asabe, K.; Nishida, T.; Fujiwara, M.

    1993-09-01

    Oxide dispersion strengthened (ODS) ferritic steels with excellent swelling resistance and superior high temperature strength are prospective cladding materials for advanced fast breeder reactors. The addition of Ti in 13Cr-3W ODS ferritic steels improved the high temperature strength remarkably by the formation of uniformly distributed ultra-fine oxide particles. ODS ferritic steels have a bamboo-like grain structure and a strong deformation texture. The decrease of creep rupture strength in the bi-axial direction compared to the uni-axial direction is attributed mainly to this unique bamboo grain structure. Nearly equivalent creep rupture strength for both bi-axial and uni-axial direction was successfully attained by introducing the α to γ transformation in ODS martensitic steel.

  3. Optimal interface between principal deterrent systems and material accounting

    International Nuclear Information System (INIS)

    The purpose of this study is to find an optimal blend between three safeguards systems for special nuclear material (SNM), the material accounting system and the physical security and material control systems. The latter two are denoted as principal deterrent systems. The optimization methodology employed is a two-stage decision algorithm, first an explicit maximization of expected diverter benefits and subsequently a minimization of expected defender costs for changes in material accounting procedures and incremental improvements in the principal deterrent systems. The probability of diverter success function dependent upon the principal deterrents and material accounting system variables is developed. Within the range of certainty of the model, existing material accounting, material control and physical security practices are justified

  4. Fabrication and property of high-performance Ag-Pb-Sb-Te system semiconducting thermoelectric materials

    Institute of Scientific and Technical Information of China (English)

    ZHOU Min; LI JingFeng; WANG Heng

    2007-01-01

    High performance Ag-Pb-Sb-Te system thermoelectric bulk materials were fabricated by a combination of mechanical alloying (MA) and spark plasma sintering (SPS). Phase composition and microstructure of the resultant materials were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. A special emphasis was paid to the effects of chemical composition, especially the Pb content on the thermoelectric properties of the Ag0.8Pb18+xSbTe20 samples, including electrical resistivity, Seebeck coefficient, power factor, thermal conductivity and dimensionless figure of merit.The present study reveals that the optimal composition of Ag0.8Pb18+xSbTe20 samples is Ag0.8Pb22.5SbTe20 and the maximum figure of merit (ZT) is 1.2 at 673 K.

  5. DSC Analysis Of Order–Disorder Transition In Ni3Al Based Alloys From Ni-Al-Cr System

    Directory of Open Access Journals (Sweden)

    Maciąg T.

    2015-09-01

    Full Text Available Ni-Al-Cr system is significant for industrial alloys based on intermetallic phase Ni3Al, that crystallizes in crystal lattice L12. It is indicated as γ′, contrary to disordered phase γ which occurs with addition of chromium. DSC analysis was performed on alloys of chemical composition from Ni75Al25÷Ni75Cr25 range of Ni-rich part of Ni-Al-Cr system. In addition, few measurements were conducted using DTA method. Based on curves registered, it was possible to identify characteristic temperature during heating and cooling of the sample. It corresponds to existence of phase boundary γ′+γ / γ in examined alloys. Results of thermal analysis were compared with results obtained with other method performed by authors which is solution calorimetric method.

  6. Material effects in LMFBR sodium systems

    International Nuclear Information System (INIS)

    The operating conditions of commercial LMFBR's can result in material performance problems. Corrosion, radiation damage, temperature requirements, plastic deformation, and the superposition of these effects have been defined as important limiting factors for the design of components. A detailed knowledge of the various parameters which can influence the behavior of materials under LMFBR conditions is therefore necessary. The objective of the paper is to identify the influence of the sodium environment on the most important properties of materials which are used for the construction of heat transfer components. The paper considers the fuel cladding, the IHX, and the steam generator to be the major heat exchange units to be evaluated

  7. Metastable phases in the aluminum-germanium alloy system: Synthesis by mechanical alloying and pressure induced transformations

    Energy Technology Data Exchange (ETDEWEB)

    Yvon, P.

    1994-01-01

    Al and Ge form a simple equilibrium eutectic with limited mutual solubility and no intermetallic intermediate phases. We used a regular solution approach to model effects of pressure on Al-Ge. Effects of pressure are to extend solubility of Ge in Al, to displace the eutectic composition towards the Ge rich side, and to slightly decrease the eutectic temperature. We designed thermobaric treatments to induce crystal-to-glass transformations in fine grain mixtures of Al and Ge. We used Merrill-Bassett diamond anvil cells to perform experiments at high pressures. We built an x-ray apparatus to determine the structure of alloys at pressure and from cryogenic temperatures to 400C. Two-phase Al-Ge samples with fine microstructures were prepared by splat-quenching and mechanical alloying. We observed a crystal-to-glass transformation at about 80 kbar. The amorphous phase formed was metastable at ambient temperature after pressure release. This was confirmed by TEM. The amorphous phase obtained by pressurization was found to have a liquid-like structure and was metallic. In the TEM samples we also observed the presence of a second amorphous phase formed upon release of the pressure. This second phase had a tetrahedrally-bonded continuous random network structure, similar to that of semi-conducting amorphous germanium.

  8. Lead telluride alloy thermoelectrics

    Directory of Open Access Journals (Sweden)

    Aaron D. LaLonde

    2011-11-01

    Full Text Available The opportunity to use solid-state thermoelectrics for waste heat recovery has reinvigorated the field of thermoelectrics in tackling the challenges of energy sustainability. While thermoelectric generators have decades of proven reliability in space, from the 1960s to the present, terrestrial uses have so far been limited to niche applications on Earth because of a relatively low material efficiency. Lead telluride alloys were some of the first materials investigated and commercialized for generators but their full potential for thermoelectrics has only recently been revealed to be far greater than commonly believed. By reviewing some of the past and present successes of PbTe as a thermoelectric material we identify the issues for achieving maximum performance and successful band structure engineering strategies for further improvements that can be applied to other thermoelectric materials systems.

  9. Capability assessment for application of clay mixture as barrier material for irradiated zirconium alloy structure elements long-term processing for storage during decommissioning of uranium-graphite nuclear reactors

    Science.gov (United States)

    Kotlyarevskiy, S. G.; Pavliuk, A. O.; Zakharova, E. V.; Volkova, A. G.

    2016-06-01

    The radionuclide composition and the activity level of the irradiated zirconium alloy E110, the radionuclide immobilization strength and the retention properties of the mixed clay barrier material with respect to the radionuclides identified in the alloy were investigated to perform the safety assessment of handling structural units of zirconium alloy used for the technological channels in uranium-graphite reactors. The irradiated zirconium alloy waste contained the following activation products: 93mNb and the long-lived 94Nb, 93Zr radionuclides. Radionuclides of 60Co, 137Cs, 90Sr, and actinides were also present in the alloy. In the course of the runs no leaching of niobium and zirconium isotopes from the E110 alloy was detected. Leach rates were observed merely for 60Co and 137Cs present in the deposits formed on the internal surface of technological channels. The radionuclides present were effectively adsorbed by the barrier material. To ensure the localization of radionuclides in case of the radionuclide migration from the irradiated zirconium alloy into the barrier material, the sorption properties were determined of the barrier material used for creating the long-term storage point for the graphite stack from uranium-graphite reactors.

  10. Hydride storage systems consisting of Al alloys for the decoupling of heat and electricity; Hydridspeicher aus Al-Legierungen zur Entkopplung von Waerme und Strom

    Energy Technology Data Exchange (ETDEWEB)

    Urbanczyk, Robert; Peil, Stefan [Institut fuer Energie- und Umwelttechnik e.V., Duisburg (Germany); Peinecke, Kateryna; Felderhoff, Michael; Hauschild, Klaus [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany)

    2012-07-01

    The authors of the contribution under consideration report on the development of a H{sub 2} solid state storage system consisting of aluminium alloys. The storage system was assembled from an extruded round rod consisting of the Aluminium alloy EN AW 6082 T6. Also an extruded heat transmission structure consisting of EN AW 6060 T6 was used as a bayonet heat exchanger. The heat transfer medium consisted of a circulating thermal oil. The storage system was filled with a complex metal hydride Na{sub 3}AlH{sub 6} and operated in several cycles of hydrogenation and dehydrogenation. Theoretically, Na{sub 3}AlH{sub 6} stores 3 mass-% hydrogen and is hydrogenated and dehydrogenated at lower pressures in contrast to the dehydrogenation preliminary stage NaAlH{sub 4}. The storage material was dehydrogenated at a temperature of nearly 180 Celsius and at a pressure of 15 bar H{sub 2}. The authors discuss the operation of the storage system in stationary applications. Stationary storage systems can be produced in a simply manner and in large quantities by means of the implanted extrusion process.

  11. Directional solidification processing of eutectic alloys in the Ni Al V system

    Science.gov (United States)

    Milenkovic, S.; Coelho, A. A.; Caram, R.

    2000-04-01

    Intermetallic matrix composites (IMCs) offer attractive properties, such as high toughness of the metal coupled with low density, high modulus and high strength of the intermetallics. Among a large number of the intermetallics, a particular interest has been shown in the NiAl intermetallic compound, since it exhibits several advantages over the currently used nickel-based superalloys. Recently, there has been a renewed interest in directional solidification of the eutectic alloys as a concept of reinforcing intermetallics with in situ refractory metals. The present study is related to the study of the eutectic alloys in the ternary NiAl-V system. The eutectic composition and temperature were accurately determined. It was concluded that the solidification behaviour of the Ni-Al-V eutectic is strongly dependent on the growth conditions, namely growth rate and orientation, and that it can be easily modified. Also, it was observed that the orientation of the grain, i.e., the direction of growth is the determining factor in the lamellar/rod transition as well as in the morphology of the degenerated structure.

  12. Heavy vehicle propulsion system materials program semiannual progress report for April 1998 thru September 1998

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.

    1999-01-01

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1--3 trucks to realize a 35{percent} fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7--8 trucks. The Office of Transportation Technologies, Office of Heavy Vehicle Technologies (OTT OHVT) has an active program to develop the technology for advanced LE-55 diesel engines with 55{percent} efficiency and low emissions levels of 2.0 g/bhp-h NO{sub x} and 0.05 g/bhp-h particulates. The goal is also for the LE-55 engine to run on natural gas with efficiency approaching that of diesel fuel. The LE-55 program is being completed in FY 1997 and, after approximately 10 years of effort, has largely met the program goals of 55{percent} efficiency and low emissions. However, the commercialization of the LE-55 technology requires more durable materials than those that have been used to demonstrate the goals. Heavy Vehicle Propulsion System Materials will, in concert with the heavy-duty diesel engine companies, develop the durable materials required to commercialize the LE-55 technologies.

  13. Surface Characterization and Cell Response of Binary Ti-Ag Alloys with CP Ti as Material Control

    Institute of Scientific and Technical Information of China (English)

    B.B. Zhang; K.J. Qiu; B.L. Wang; L. Li; Y.F. Zheng

    2012-01-01

    In this study, the surface passive films, dissolution behavior and biocompatibility of Ti-Ag alloys (with 5%, 10% and 20% Ag) were evaluated by X-ray diffraction (XRD) tests, electrochemical corrosion tests, X-ray photoelectron spectroscopy (XPS) tests, dissolution tests and in-vitro cytotoxicity tests. The surface films on the Ti-20Ag alloy are rich in Ti and much deficient in Ag with respect to alloy composition, as identified by XPS. Compared to CP Ti, Ti-SAg and Ti-20Ag alloys show larger impedances and lower capacitances, which can be associated with an increase of the passive layer thickness. Moreover, all Ti-Ag alloys exhibit negligible or low metal release in the test solutions. The in-vitro cytotoxicity results show Ti-Ag alloys seem to be as cytocompatible as CP Ti. From the viewpoint of surface passive film and cytotoxicity, Ti-SAg and Ti-20Ag are considered to be more suitable for dental applications.

  14. An innovative seismic bracing system based on a superelastic shape memory alloy ring

    Science.gov (United States)

    Gao, Nan; Jeon, Jong-Su; Hodgson, Darel E.; DesRoches, Reginald

    2016-05-01

    Shape memory alloys (SMAs) have great potential in seismic applications because of their remarkable superelasticity. Seismic bracing systems based on SMAs can mitigate the damage caused by earthquakes. The current study investigates a bracing system based on an SMA ring which is capable of both re-centering and energy dissipation. This lateral force resisting system is a cross-braced system consisting of an SMA ring and four tension-only cable assemblies, which can be applied to both new construction and seismic retrofit. The performance of this bracing system is examined through a quasi-static cyclic loading test and finite element (FE) analysis. This paper describes the experimental design in detail, discusses the experimental results, compares the performance with other bracing systems based on SMAs, and presents an Abaqus FE model calibrated on the basis of experimental results to simulate the superelastic behavior of the SMA ring. The experimental results indicate that the seismic performance of this system is promising in terms of damping and re-centering. The FE model can be used in the simulation of building structures using the proposed bracing system.

  15. Microstructural studies on variation of defect parameters in Zr–Sn alloys and their transition with interchange of solvent and solute in Zr–Ti and Ti–Zr alloy systems by modified Rietveld method and Warren–Averbach method

    Indian Academy of Sciences (India)

    J Ghosh; S K Chattopadhyay; A K Meikap; S K Chatterjee

    2006-08-01

    The effects of deformation and the transition of microstructural defect states with the interchange of solvent and solute in Ti–Zr and Zr–Ti alloys of six different compositions and Zr–Sn alloys in three different compositions have been investigated by X-ray diffraction line profile analysis. The detailed analysis of the X-ray powder diffraction line profiles was interpreted by Fourier line shape analysis using modified Rietveld method and Warren–Averbach method taking silicon as standard. Finally the microstructural parameters such as coherent domain size, microstrains within domains, faulting probability and dislocation density were evaluated from the analysis of X-ray powder diffraction data of Zr base Sn, Ti and Ti base Zr alloys by modified Rietveld powder structure refinement. This analysis confirms that the growth fault, , is totally absent or negligibly present in Zr–Ti, Ti–Zr and Zr–Sn alloy systems, because the growth fault, , has been observed to be either negative or very small for these alloy systems. This analysis also revealed that the deformation fault, , has significant presence in titanium-base zirconium alloy systems but when zirconium content in the matrix goes on increasing beyond 50%, this faulting behaviour suffers a drastic transition and faulting tendency abruptly drops to a level of negligible presence or zero. This tendency has also been observed in Zr–Sn alloys signifying high stacking fault energy. Therefore, Zr and Zr-base alloys having high stacking fault energy can be used as hard alloys in nuclear technology at high temperature.

  16. 快堆先进包壳材料ODS合金发展研究%R &D on advanced cladding materials ODS alloys for fast reactor

    Institute of Scientific and Technical Information of China (English)

    崔超; 黄晨; 苏喜平; 宿彦京

    2011-01-01

    Fast reactor advanced cladding materials ODS alloys (Oxide Dispersion Strengthened steel) have excellent irradiation swelling resistance and stable mechanical properties at elevated temperature, which is chosen as the candidate cladding material of high burnup fuel for fast reactor. This paper generally introduces the progress of R&D on ODS alloys, including the processing technology of ODS alloys, mechanical properties, compatibility with sodium, irradiation performance and so on.%快堆先进包壳材料ODS合金(Oxide Dispersion Strengthened Steel)具有优异的抗辐照肿胀性能和高温力学性能,是高性能快堆燃料元件包壳管的主要候选材料.本文概括介绍了ODS合金的研究进展,包括ODS合金的制备方法、力学性能、与钠相容性以及辐照性能等.

  17. High-temperature thermal storage systems for advanced solar receivers materials selections

    Science.gov (United States)

    Wilson, D. F.; Devan, J. H.; Howell, M.

    1990-01-01

    Advanced space power systems that use solar energy and Brayton or Stirling heat engines require thermal energy storage (TES) systems to operate continuously through periods of shade. The receiver storage units, key elements in both Brayton and Stirling systems, are designed to use the latent heat of fusion of phase-change materials (PCMs). The power systems under current consideration for near-future National Aeronautics and Space Administration space missions require working fluid temperatures in the 1100 to 1400 K range. The PCMs under current investigation that gave liquid temperatures within this range are the fluoride family of salts. However, these salts have low thermal conductivity, which causes large temperature gradients in the storage systems. Improvements can be obtained, however, with the use of thermal conductivity enhancements or metallic PCMs. In fact, if suitable containment materials can be found, the use of metallic PCMs would virtually eliminate the orbit associated temperature variations in TES systems. The high thermal conductivity and generally low volume change on melting of germanium and alloys based on silicon make them attractive for storage of thermal energy in space power systems. An approach to solving the containment problem, involving both chemical and physical compatibility, preparation of NiSi/NiSi2, and initial results for containment of germanium and NiSi/NiSi2, are presented.

  18. The Conductive Thermal Control Material Systems for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is submitted to develop and demonstrate the feasibility of processing the space environment stable, multifunctional thermal control material system...

  19. Materials And Processes Technical Information System (MAPTIS) LDEF materials data base

    Science.gov (United States)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated from LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux) and author(s) or principal investigator(s). Tne LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which has been computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. The LDEF Materials Data Base is described and step-by-step example searches using the data base are included. Information on how to become an authorized user of the system is included.

  20. Study of the magnetic properties, structure, and phase transformation in the alloys of the Co-Al-W system

    Energy Technology Data Exchange (ETDEWEB)

    Davidov, D. I., E-mail: davidov@imp.uran.ru; Stepanova, N. N., E-mail: SNN@imp.uran.ru; Kazantseva, N. V., E-mail: kazantseva@imp.uran.ru; Rigmant, M. B., E-mail: rigmant@imp.uran.ru; Shishkin, D. A., E-mail: shishkin@imp.uran.ru [M.N. Miheev Institute of Metal Physics UrB RAS, Yekaterinburg, 620990 (Russian Federation)

    2015-10-27

    An experimental study of phase transformations in the system of Co-Al-W in the concentration area of the intermetallic compound Co{sub 3}(Al, W) is presented. The structure and phase composition of the Co–9 at % Al–X at % W (X = 4.5, 6.8, 8.5, 10, 12.5) alloys in depending on the tungsten content are analyzed. The Curie temperature and magnetic properties of the alloys with the different phase composition are determined.

  1. Application of the Materials-by-Design Methodology to Redesign a New Grade of the High-Strength Low-Alloy Class of Steels with Improved Mechanical Properties and Processability

    Science.gov (United States)

    Grujicic, M.; Snipes, J. S.; Ramaswami, S.

    2016-01-01

    An alternative to the traditional trial-and-error empirical approach for the development of new materials is the so-called materials-by-design approach. Within the latter approach, a material is treated as a complex system and its design and optimization is carried out by employing computer-aided engineering analyses, predictive tools, and available material databases. In the present work, the materials-by-design approach is utilized to redesign a grade of high-strength low-alloy (HSLA) class of steels with improved mechanical properties (primarily strength and fracture toughness), processability (e.g., castability, hot formability, and weldability), and corrosion resistance. Toward that end, a number of material thermodynamics, kinetics of phase transformations, and physics of deformation and fracture computational models and databases have been developed/assembled and utilized within a multi-disciplinary, two-level material-by-design optimization scheme. To validate the models, their prediction is compared against the experimental results for the related steel HSLA100. Then the optimization procedure is employed to determine the optimal chemical composition and the tempering schedule for a newly designed grade of the HSLA class of steels with enhanced mechanical properties, processability, and corrosion resistance.

  2. Effects of alloying and local order in AuNi contacts for Ohmic radio frequency micro electro mechanical systems switches via multi-scale simulation

    Science.gov (United States)

    Gaddy, Benjamin E.; Kingon, Angus I.; Irving, Douglas L.

    2013-05-01

    Ohmic RF-MEMS switches hold much promise for low power wireless communication, but long-term degradation currently plagues their reliable use. Failure in these devices occurs at the contact and is complicated by the fact that the same asperities that bear the mechanical load are also important to the flow of electrical current needed for signal processing. Materials selection holds the key to overcoming the barriers that prevent widespread use. Current efforts in materials selection have been based on the material's (or alloy's) ability to resist oxidation as well as its room-temperature properties, such as hardness and electrical conductivity. No ideal solution has yet been found via this route. This may be due, in part, to the fact that the in-use changes to the local environment of the asperity are not included in the selection criteria. For example, Joule heating would be expected to raise the local temperature of the asperity and impose a non-equilibrium thermal gradient in the same region expected to respond to mechanical actuation. We propose that these conditions should be considered in the selection process, as they would be expected to alter mechanical, electrical, and chemical mechanisms in the vicinity of the surface. To this end, we simulate the actuation of an Ohmic radio frequency micro electro mechanical systems switch by using a multi-scale method to model a current-carrying asperity in contact with a polycrystalline substrate. Our method couples continuum solutions of electrical and thermal transport equations to an underlying molecular dynamics simulation. We present simulations of gold-nickel asperities and substrates in order to evaluate the influence of alloying and local order on the early stages of contact actuation. The room temperature response of these materials is compared to the response of the material when a voltage is applied. Au-Ni interactions are accounted for through modification of the existing Zhou embedded atom method

  3. The thermal field contactless monitoring system for welding and local heat treatment of the zirconium alloys tubes

    International Nuclear Information System (INIS)

    One of the most controllable parameters at welding and heat treatment of ring joints from zirconium alloys are distribution and gradual change of temperature field in treatment zone. The proposed system is firmware complex which allows to measure contactless temperature field according to its thermal radiation

  4. Planning and Computerised Monitoring of an Experiment of Thermal Analysis of the Alloys in the Al-Cu-Si System

    Directory of Open Access Journals (Sweden)

    Florentina Cziple

    2007-10-01

    Full Text Available The paper presents an installation conceived for the automatic registration of the temperature in the thermal analysis, at the industrial and laboratory level, with application to the system of non-ferrous alloys Al-Cu-Si. The experiment performed on the above installation is compared to processes monitored through simulation with specialised software.

  5. Materials selection guidelines for geothermal power systems. First edition

    Energy Technology Data Exchange (ETDEWEB)

    DeBerry, D.W.; Ellis, P.F.; Thomas, C.C.

    1978-09-01

    Nine potential power cycles are defined and diagrammed for the generation of electricity from geothermal fluids. General fluid properties that influence the applicability of power cycles to a particular geothermal resource are discussed. The corrosivity of individual process streams in power cycles is described based on variations in chemical composition and temperature. Results of materials performance tests are analyzed based on the chemical composition of the corrosive medium and physical factors such as temperature, duration of exposure, and fluid velocity. The key chemical components in geothermal fluids that are significant in determining corrosivity are identified. Both summarized and detailed results of materials performance tests in U.S. liquid-dominated resources are given. Seven U.S. liquid-dominated KGRA's are classified according to relative corrosiveness and their key chemical components are defined. The various forms and mechanisms of corrosive attack that can occur in geothermal process streams are described. The application of nonmetallic materials in geothermal environments is discussed. The appendices contain information on (1) operating experience at geothermal power plants, (2) corrosion in desalination facilities, (3) reliability of geothermal plants, (4) elastomeric materials, (5) comparative alloy costs, and (6) geothermal equipment manufacturers. (MHR)

  6. Corrosion resistant amorphous alloys

    International Nuclear Information System (INIS)

    A review of publication data on corrosion resistance of amorphous alloys and the methods of amorphization of surface layers of massive materials (laser treatment, iron implantation, detonation-gas spraying, cathode and ion sputtering, electrodeposition) was made. A study was made on corrosion properties of Fe66Cr11B10Si4 alloy in cast state and after laser irradiation, rendering the surface amorphous as well as the samples of Arenco iron and steel 20 with ion-plasma coatings of Fe-Cr-Ni-Ti alloy. It was established that amorphous coatings posses much higher corrosion resistance as compared to crystalline alloys on the same base

  7. Computerized real-time materials accountability system for safeguards material control

    International Nuclear Information System (INIS)

    A real-time, computer-based system is described which provides safeguards material control at the Oak Ridge National Laboratory. Originally installed in 1972 to provide computerized real-time fissile materials accountability for criticality control purposes, the system has been expanded to provide accountability of all source and nuclear materials (SNM) and to utilize the on-line inventory files in support of the Laboratory physical protection and surveillance procedures. (auth)

  8. Dezincification and Brass Lead Leaching in Premise Plumbing Systems: Effects of Alloy, Physical Conditions and Water Chemistry

    OpenAIRE

    Zhang, Yaofu

    2009-01-01

    Brass components are widely used in drinking water distribution systems as valves, faucets and other fixtures. They can be corroded by â dezincification,â which is the selective leaching of zinc from the alloy. Dezincification in potable water systems has important practical consequences that include clogged water lines, premature system failure and leaks, and release of contaminants such as lead. Brass failures attributed to dezincification are known to occur at least occasionally all ove...

  9. DENSITY-FUNCTIONAL STUDY OF Zr-BASED ACTINIDE ALLOYS: 2. U-Pu-Zr SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Landa, A; Soderlind, P; Turchi, P; Vitos, L; Ruban, A

    2009-02-09

    Density-functional theory, previously used to describe phase equilibria in the U-Zr alloys [1], is applied to study ground state properties of the bcc U-Pu-Zr solid solutions. Calculated heats of formation of the Pu-U and Pu-Zr alloys are in a good agreement with CALPHAD assessments. We found that account for spin-orbit coupling is important for successful description of Pu-containing alloys.

  10. Design and fabrication of a mechanical alloying system for preparing intermetallic, nanocrystalline, amorphous and quasicrystalline compounds; Diseno y fabricacion de un sistema de aleado mecanico para preparar compuestos intermetalicos, nanocristalinos, amorfos y cuasicristalinos

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio M, J.; Iturbe G, J.L.; Castaneda J, G. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work a grinding system was designed and fabricated which allowed to improve the operation conditions in time, frequency, temperature and selection of the grinding media and that allow the contamination decrease of the compounds. By means of this method of mechanical alloying new metallic compounds can be produced, starting from elemental powders, with fine and controlled microstructures. These compounds prepared by this method are going to be used as materials for the hydrogen storage. (Author)

  11. Preparation and certification of certified reference materials JAERI-Z21, Z22 and Z23 for analysis of zirconium and its alloys

    International Nuclear Information System (INIS)

    The Sub-Committee on Chemical Analysis of Nuclear Materials was organized in April 1987, under the Committee on Analytical Chemistry of Nuclear Fuels and Reactor Materials, JAERI, for renewal of certified reference materials of zirconium base alloys and zirconium metal. Collaborative analysis was carried out among ten participating laboratories for the certification of the JAERI CRMs Z21 to Z23. As a results of the collaborative works, the certified values for sixteen elements (Sn, Fe, Ni, Cr, Hf, Al, Si, Co, Cu, Ti, Mn, Pb, U, Cd, B and W) in the CRMs were given. In this report, preparation of raw materials, homogeneity test, chemical analysis for certification by collaborative works during April 1987 to March 1990 are described. (author)

  12. Preparation of High-performance and Low-VOC PC/ABS Alloy Material With Environmental Friendly%高性能低VOC环保PC/ABS合金材料的制备

    Institute of Scientific and Technical Information of China (English)

    申娟; 苏昱

    2016-01-01

    以聚碳酸酯(PC)、丙烯腈–丁二烯–苯乙烯塑料(ABS)为基体树脂,加入聚烯烃弹性体(POE)、抗氧剂及其它助剂共混挤出造粒,制成低挥发性有机化合物(VOC)的环保PC/ABS合金材料。在用增韧剂POE及抗氧剂对PC/ABS体系进行改性的同时,探讨PC/ABS基料、增韧剂、抗氧剂对PC/ABS合金的力学性能、VOC及气味等级的影响,从而得到具有高性能、低VOC、低气味的环保PC/ABS合金材料,以期在汽车内饰件等方面得到应用。%Based on polycarbonate (PC),acrylonitrile–butadiene–styrene plastic (ABS) as matrix resin,by adding polyolefin elastomer (POE),antioxidants and other additives blended extrusion granulation,low-volatile organic compounds (VOC) PC/ABS alloy material which is always be friendly to environment was made. With toughening POE and antioxidants for PC/ABS system modified,the impact of PC/ABS binder,plasticizer,antioxidant on mechanical properties,VOC and odor level of PC/ABS alloys was explored. Thereby,a high-performance low-VOC PC/ABS alloy material was obtained in order to get application in the automotive interior.

  13. MATERIAL HANDLING IN FLEXIBLE MANUFACTURING SYSTEM

    Directory of Open Access Journals (Sweden)

    Mr. Neeraj Dahiya

    2011-08-01

    Full Text Available The objective of this study is to analyze the system performanceof a flexible manufacturing system cell. The study givesinformation on production potential of the cell by groupingcommon parts. To complete this, computer simulation models aredeveloped using the SIMAN simulation language. Initially nomaterial handling is provided to the manufacturing system to getan upper bound estimate of production output. Next, we explorethe impact that an automatic guided vehicle (AGV has on systemperformance with manufacturing system. The final analysis isperformed in which a conveyor is implemented for the materialhandling. The performance result with comparison is presented inthe form of confidence intervals. After examine the simulationresults, we recommend to implement a conveyor system formaterial handling. Use of AGV in the flexible manufacturingsystem creates a bottleneck which causes a dramatically decreasein the production: as compare to a conveyor as the materialhandling system which does not limit the daily production outputof the manufacturing cell.

  14. Adaptive and active materials: selected papers from the ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 13) (Snowbird, UT, USA, 16-18 September 2013)

    Science.gov (United States)

    Johnson, Nancy; Naguib, Hani; Turner, Travis; Anderson, Iain; Bassiri-Gharb, Nazanin; Daqaq, Mohammed; Baba Sundaresan, Vishnu; Sarles, Andy

    2014-10-01

    The sixth annual meeting of the ASME Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) was held in the beautiful mountain encircled Snowbird Resort and Conference Center in Little Cottonwood Canyon near Salt Lake City, Utah. It is the conference's objective to provide an up-to-date overview of research trends in the entire field of smart materials systems in a friendly casual forum conducive to the exchange of ideas and latest results. As each year we strive to grow and offer new experiences, this year we included special focused topic tracks on nanoscale multiferroic materials and origami engineering. The cross-disciplinary emphasis was reflected in keynote speeches by Professor Kaushik Bhattacharya (California Institute of Technology) on 'Cyclic Deformation and the Interplay between Phase Transformation and Plasticity in Shape Memory Alloys', by Professor Alison Flatau (University of Maryland at College Park) on 'Structural Magnetostrictive Alloys: The Other Smart Material', and by Dr Leslie Momoda (Director of the Sensors and Materials Laboratories, HRL Laboratories, LLC, Malibu, CA) on 'Architecturing New Functional Materials: An Industrial Perspective'. SMASIS 2013 was divided into seven symposia which span basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. SYMP 1. Development and Characterization of Multifunctional Materials. SYMP 2. Mechanics and Behavior of Active Materials. SYMP 3. Modeling, Simulation and Control of Adaptive Systems. SYMP 4. Integrated System Design and Implementation. SYMP 5. Structural Health Monitoring. SYMP 6. Bioinspired Smart Materials and Systems. SYMP 7. Energy Harvesting. Authors of selected papers in the materials areas (symposia 1, 2, and 6) as well as energy harvesting (symposium 7) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart

  15. Material Systems for Blast-Energy Dissipation

    Energy Technology Data Exchange (ETDEWEB)

    James Schondel; Henry S. Chu

    2010-10-01

    Lightweight panels have been designed to protect buildings and vehicles from blast pressures by activating energy dissipation mechanisms under the influence of blast loading. Panels were fabricated which featured a variety of granular materials and hydraulic dissipative deformation mechanisms and the test articles were subjected to full-scale blast loading. The force time-histories transmitted by each technology were measured by a novel method that utilized inexpensive custom-designed force sensors. The array of tests revealed that granular materials can effectively dissipate blast energy if they are employed in a way that they easily crush and rearrange. Similarly, hydraulic dissipation can effectively dissipate energy if the panel features a high fraction of porosity and the panel encasement features low compressive stiffness.

  16. Dynamic modelling of packaging material flow systems.

    Science.gov (United States)

    Tsiliyannis, Christos A

    2005-04-01

    A dynamic model has been developed for reused and recycled packaging material flows. It allows a rigorous description of the flows and stocks during the transition to new targets imposed by legislation, product demand variations or even by variations in consumer discard behaviour. Given the annual reuse and recycle frequency and packaging lifetime, the model determines all packaging flows (e.g., consumption and reuse) and variables through which environmental policy is formulated, such as recycling, waste and reuse rates and it identifies the minimum number of variables to be surveyed for complete packaging flow monitoring. Simulation of the transition to the new flow conditions is given for flows of packaging materials in Greece, based on 1995--1998 field inventory and statistical data. PMID:15864957

  17. MATERIAL HANDLING IN FLEXIBLE MANUFACTURING SYSTEM

    OpenAIRE

    Mr. Neeraj Dahiya; Mr. Neeraj Nirmal

    2011-01-01

    The objective of this study is to analyze the system performanceof a flexible manufacturing system cell. The study givesinformation on production potential of the cell by groupingcommon parts. To complete this, computer simulation models aredeveloped using the SIMAN simulation language. Initially nomaterial handling is provided to the manufacturing system to getan upper bound estimate of production output. Next, we explorethe impact that an automatic guided vehicle (AGV) has on systemperforma...

  18. Composite materials in flexible multibody systems

    OpenAIRE

    Neto, Maria Augusta; Ambrósio, Jorge A. C.; Leal, Rogério P.

    2006-01-01

    In this work the flexible multibody dynamics formulations of complex models are extended to include elastic components made of laminated composite materials. The only limitation for the deformation of a structural member is that it must be elastic and linear when described in a body fixed frame. A finite element model for each flexible body is obtained such that the nodal coordinates are described with respect to the body fixed frame and the inertia terms involved in the mass matrix and gyros...

  19. Design and Fabrication of Monolithically-Integrated Laterally-Arrayed Multiple Band Gap Solar Cells using Composition-Graded Alloy Nanowires for Spectrum-Splitting Photovoltaic Systems

    Science.gov (United States)

    Caselli, Derek

    This dissertation aims to demonstrate a new approach to fabricating solar cells for spectrum-splitting photovoltaic systems with the potential to reduce their cost and complexity of manufacturing, called Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells. Single crystal semiconductor alloy nanowire (NW) ensembles are grown with the alloy composition and band gap changing continuously across a broad range over the surface of a single substrate in a single, inexpensive growth step by the Dual-Gradient Method. The nanowire ensembles then serve as the absorbing materials in a set of solar cells for spectrum-splitting photovoltaic systems. Preliminary design and simulation studies based on Anderson's model band line-ups were undertaken for CdPbS and InGaN alloys. Systems of six subcells obtained efficiencies in the 32-38% range for CdPbS and 34-40% for InGaN at 1-240 suns, though both materials systems require significant development before these results could be achieved experimentally. For an experimental demonstration, CdSSe was selected due to its availability. Proof-of-concept CdSSe nanowire ensemble solar cells with two subcells were fabricated simultaneously on one substrate. I-V characterization under 1 sun AM1.5G conditions yielded open-circuit voltages (Voc) up to 307 and 173 mV and short-circuit current densities (Jsc) up to 0.091 and 0.974 mA/cm2 for the CdS- and CdSe-rich cells, respectively. Similar thin film cells were also fabricated for comparison. The nanowire cells showed substantially higher Voc than the film cells, which was attributed to higher material quality in the CdSSe absorber. I-V measurements were also conducted with optical filters to simulate a simple form of spectrum-splitting. The CdS-rich cells showed uniformly higher Voc and fill factor (FF) than the CdSe-rich cells, as expected due to their larger band gaps. This suggested higher power density was produced by the CdS-rich cells on the single

  20. Low Complex System for Levitating Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Dahiru Sani Shu'aibu

    2010-06-01

    Full Text Available This paper primarily presents detailed design and implementation of a low complex magnetic levitation system which can be used in laboratory for levitation experiments. The system transfer function was derived from the coenergy and the mathematical model of the state space representation was obtained. The mathematical model showed that, the system is highly non-linear and inherently unstable. Based on simulation, a low complex circuit was designed and implemented to stabilize the system, using MATLAB control tool-box. The developed controller was simple, cheap and effective, capable of controlling weights of different masses at various distances as compared to some controllers in literature.