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Sample records for metallurgy powder

  1. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

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

  2. Biaxially textured articles formed by powder metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-07-29

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  3. Advanced powder metallurgy aluminum alloys and composites

    Science.gov (United States)

    Lisagor, W. B.; Stein, B. A.

    1982-01-01

    The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

  4. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1978-01-01

    Fuel for Savannah River Plant (SRP) reactors consists of extruded tubes with aluminum--uranium alloy cores clad with 8001 aluminum. The 235 U in the fuel is periodically recovered and recycled in new fuel assemblies. The buildup of 236 U in the enriched uranium requires increased total uranium contents to maintain reactivity in existing assembly designs. High level waste production from these tubes is proportional to the aluminum content; therefore, appreciable radioactive waste reductions result from lower aluminum--uranium ratios and thinner clad tubes. The casting process now used for fuel cores is limited to below 40 wt % U because of the reduced fabricability of high uranium alloys. To increase tube loading and reduce aluminum, the U 3 O 8 -Al powder metallurgy (P/M) process for fuel tubes is under development. Several fabricaion and irradiaion tests have been made using production conditions. Both small scale and production tests carried out at SRL for high-density P/M fuel development are discussed

  5. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallurgy (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U3O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼ 40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high-density P/M fuel development. The purpose of the P/M development program at SRL is to: determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, continue metal forming studies for extrusion and drawing, and evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes. Experimental results of testing the fuel assemblies performance so far indicate that: cores containing fine (-325 mesh) U 3 O 8 and aluminum powders can be made practically free of high-density areas using the outlined P/M pre blending and sieving techniques. U 3 O 8 -Al cores can be isostatically compacted with up to 100 wt U 3 O 8 and tubes successfully extruded with up to 80 wt oxide; fission gas blistering of U 3 O 8 -Al P/M tubes as indicated by the blister tests is a function of fissions/cc of U 3 O 8 in the core; Decreasing the fission density of oxide increases the threshold temperature for blister formation; U 3 O 8 -Al P/M fuel tubes with up to 59 wt U 3 O 8 have been successfully irradiated in SRP reactor to 1.6 x 10 21 fissions/cc of core or 7 x 10 20 fissions/cc of U 3 O 8 small

  6. Structural Description of Powder Metallurgy Prepared Materials

    Czech Academy of Sciences Publication Activity Database

    Michalcová, A.; Vojtěch, D.; Kubatík, Tomáš František; Novák, P.; Dvořák, P.

    2014-01-01

    Roč. 14, č. 3 (2014), s. 359-362 ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] Institutional support: RVO:61389021 Keywords : SPS * Intermetallics * powder metallurgy Subject RIV: JG - Metallurgy http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

  7. Powder-Metallurgy Process And Product

    Science.gov (United States)

    Paris, Henry G.

    1988-01-01

    Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

  8. Powder metallurgy bearings for advanced rocket engines

    Science.gov (United States)

    Fleck, J. N.; Killman, B. J.; Munson, H.E.

    1985-01-01

    Traditional ingot metallurgy was pushed to the limit for many demanding applications including antifriction bearings. New systems require corrosion resistance, better fatigue resistance, and higher toughness. With conventional processing, increasing the alloying level to achieve corrosion resistance results in a decrease in other properties such as toughness. Advanced powder metallurgy affords a viable solution to this problem. During powder manufacture, the individual particle solidifies very rapidly; as a consequence, the primary carbides are very small and uniformly distributed. When properly consolidated, this uniform structure is preserved while generating a fully dense product. Element tests including rolling contact fatigue, hot hardness, wear, fracture toughness, and corrosion resistance are underway on eleven candidate P/M bearing alloys and results are compared with those for wrought 440C steel, the current SSME bearing material. Several materials which offer the promise of a significant improvement in performance were identified.

  9. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallury (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U 3 O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high- density P/M fuel development. The purpose of the P/M development program at SRL is to: (1) determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, (2) irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, (3) continue metal forming studies for extrusion and drawing, and (4) evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes

  10. Titanium surgical implants processed by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.V. de [INT-DMCM, Inst. Nacional de Tecnologia, Rio de Janeiro, RJ (Brazil); Pereira, L.C. [Programa de Eng. de Materiais e Metalurgica, UFRJ-COPPE (Brazil); Schwanke, C.M.; Schaeffer, L. [Centro de Tecnologia- LdTM-INT-DMCM, UFRGS, Venezuela, CEP, Rio de Janeiro, RJ (Brazil)

    2001-07-01

    Due to their low density coupled with excellent corrosion resistance and good mechanical properties, titanium and titanium alloys have been widely used for surgical implants. They have also a relatively low young's modulus, allowing a good load transfer to the bone. The elastic modulus difference between metallic implant material and bone is large, which can lead to a fracture of the implant. To solve this problem, many implants for artificial joint and dental applications have been produced by powder metallurgy routes, obtaining a porous material with an even lower young's modulus than that of the bulk titanium. This porous structure allows bone ingrowth, as the osseous tissue invade the holes of the porous material while growing and adheres to it. Besides, near net shape technologies like powder metallurgy and injection molding techniques, can reduce the components high costs due to machining final steps, also providing a fine, uniform grain structure and lack of texture and segregation. This work outlines the characteristics, properties and some of the powder routes for producing titanium surgical implants and implant porous coatings. (orig.)

  11. Low-Cobalt Powder-Metallurgy Superalloy

    Science.gov (United States)

    Harf, F. H.

    1986-01-01

    Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

  12. Borax as a lubricant in powder metallurgy

    Directory of Open Access Journals (Sweden)

    Héctor Geovanny Ariza-Suarez

    2014-12-01

    were compacted at 700 MPa in a uniaxial press of 15 tons. DSC-TGA analysis of the mixture with borax was realized. The specimens were sintered in a plasma reactor at 1000 for 30 minutes, with a combined atmosphere of hydrogen and argon. Microhardness and density of the sintered samples was haracterized. XRD analysis was realized to detect possible compounds formation by interaction of borax. This paper shows that borax can be used as a lubricant in powder metallurgy.

  13. A major advance in powder metallurgy

    Science.gov (United States)

    Williams, Brian E.; Stiglich, Jacob J., Jr.; Kaplan, Richard B.; Tuffias, Robert H.

    1991-01-01

    Ultramet has developed a process which promises to significantly increase the mechanical properties of powder metallurgy (PM) parts. Current PM technology uses mixed powders of various constituents prior to compaction. The homogeneity and flaw distribution in PM parts depends on the uniformity of mixing and the maintenance of uniformity during compaction. Conventional PM fabrication processes typically result in non-uniform distribution of the matrix, flaw generation due to particle-particle contact when one of the constituents is a brittle material, and grain growth caused by high temperature, long duration compaction processes. Additionally, a significant amount of matrix material is usually necessary to fill voids and create 100 percent dense parts. In Ultramet's process, each individual particle is coated with the matrix material, and compaction is performed by solid state processing. In this program, Ultramet coated 12-micron tungsten particles with approximately 5 wt percent nickel/iron. After compaction, flexure strengths were measured 50 percent higher than those achieved in conventional liquid phase sintered parts (10 wt percent Ni/Fe). Further results and other material combinations are discussed.

  14. Preparation of nitinol by non-conventional powder metallurgy techniques

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Moravec, H.; Salvetr, P.; Průša, F.; Drahokoupil, Jan; Kopeček, Jaromír; Karlík, M.; Kubatík, Tomáš František

    2015-01-01

    Roč. 31, č. 15 (2015), s. 1886-1893 ISSN 0267-0836 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:68378271 ; RVO:61389021 Keywords : shape memory alloys * SHS process * SEM * powder metallurgy Subject RIV: JG - Metallurgy Impact factor: 1.008, year: 2015

  15. Introduction to powder metallurgy processes for titanium manufacturing

    International Nuclear Information System (INIS)

    Esteban, P. G.; Bolzoni, L.; Ruiz-Navas, E. M.; Gordo, E.

    2011-01-01

    The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.

  16. The effect of powder metallurgy process parameters on mechanical ...

    African Journals Online (AJOL)

    The ever-increasing development of applying the iron pieces made by powder metallurgy in car industries and other usages depends on making pieces with high density and consequently acceptable physical and mechanical properties. Regarding the effect of decrease in the powder bits' size on improvement of the ...

  17. Powder Metallurgy characteristics and application: state of the art

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2005-01-01

    Powder metallurgy process (P/M) is a near-net or net-shape manufacturing process that combines the features of shape making technology of powder compaction with the development of final material and design properties (physical and mechanical) during subsequent densification or consolidation processes, e.g. sintering. It utilizes the metal powder or powders of metal alloys. In this paper, the major historical developments in P/M are reviewed and discussed. The main parameters involved in the process and their effects on the product characteristics are presented and discussed, which include: powders and methods of their production, particle size and shape, compressibility and additives, sintering temperature and time and finishing processes. The advantages and limitations of powder metallurgy are also presented and discussed. Finally, applications and future developments of the process are outlined and discussed. (author)

  18. Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans Jr., James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nunn, Stephen D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parten, Randy J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    Powder metallurgy approaches for the fabrication of accelerator target disks are being examined to support the development of Mo-99 production by NorthStar Medical Technologies, LLC. An advantage of powder metallurgy is that very little material is wasted and, at present, dense, quality parts are routinely produced from molybdenum powder. The proposed targets, however, are thin wafers, 29 mm in diameter with a thickness of 0.5 mm, with very stringent dimensional tolerances. Although tooling can be machined to very high tolerance levels, the operations of powder feed, pressing and sintering involve complicated mechanisms, each of which affects green density and shrinkage, and therefore the dimensions and shape of the final product. Combinations of powder morphology, lubricants and pressing technique have been explored to produce target disks with minimal variations in thickness and little or no distortion. In addition, sintering conditions that produce densities for optimum target dissolvability are being determined.

  19. Damage on 316LN stainless steel transformed by powder metallurgy

    International Nuclear Information System (INIS)

    Couturier, R.; Burlet, H.

    1998-01-01

    This study deals with the 316 LN stainless steel elaboration by powder metallurgy. This method allows the realization of structures in austenitic steel less affected by the thermal aging than the cast austenitic-ferritic components. The components are performed by the method of HIP (Hot Isostatic Pressing). Mechanical tests are provided to control mechanical properties

  20. [Hygienic evaluation of risk factors on powder metallurgy production].

    Science.gov (United States)

    2011-01-01

    Complex hygienic, clinical, sociologic and epidemiologic studies revealed reliable relationship between work conditions and arterial hypertension, locomotory system disorders, monocytosis in powder metallurgy production workers. Findings are more probable cardiovascular and respiratory diseases, digestive tract diseases due to influence of lifestyle factors.

  1. Powder-metallurgy superalloy strengthened by a secondary gamma phase.

    Science.gov (United States)

    Kotval, P. S.

    1971-01-01

    Description of experiments in which prealloyed powders of superalloy compositions were consolidated by extrusion after the strengthening by precipitation of a body-centered tetragonal gamma secondary Ni3 Ta phase. Thin foil electron microscopy showed that the mechanical properties of the resultant powder-metallurgy product were correlated with its microstructure. The product exhibited high strength at 1200 F without loss of ductility, after thermomechanical treatment and aging.

  2. Powder Metallurgy Reconditioning of Food and Processing Equipment Components

    Science.gov (United States)

    Nafikov, M. Z.; Aipov, R. S.; Konnov, A. Yu.

    2017-12-01

    A powder metallurgy method is developed to recondition the worn surfaces of food and processing equipment components. A combined additive is composed to minimize the powder losses in sintering. A technique is constructed to determine the powder consumption as a function of the required metallic coating thickness. A rapid method is developed to determine the porosity of the coating. The proposed technology is used to fabricate a wear-resistant defectless metallic coating with favorable residual stresses, and the adhesive strength of this coating is equal to the strength of the base metal.

  3. Powder metallurgy in aerospace research: A survey

    Science.gov (United States)

    Blakeslee, H. W.

    1971-01-01

    The various techniques by which powders can be produced, as pure metals or as alloys, are discussed; the methods by which these powders can be formed into the final parts are explained as well as further processing that may be necessary to meet specific requirements. The NASA developments are detailed, and references are provided for those who wish to obtain further information characteristic of any methodology.

  4. Advanced powder metallurgy aluminum alloys via rapid solidification technology

    Science.gov (United States)

    Ray, R.

    1984-01-01

    Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

  5. Microstructure and Aging of Powder-Metallurgy Al Alloys

    Science.gov (United States)

    Blackburn, L. B.

    1987-01-01

    Report describes experimental study of thermal responses and aging behaviors of three new aluminum alloys. Alloys produced from rapidly solidified powders and contain 3.20 to 5.15 percent copper, 0.24 to 1.73 percent magnesium, 0.08 to 0.92 percent iron, and smaller amounts of manganese, nickel, titanium, silicon, and zinc. Peak hardness achieved at lower aging temperatures than with standard ingot-metallurgy alloys. Alloys of interest for automobile, aircraft, and aerospace applications.

  6. Laboratory Powder Metallurgy Makes Tough Aluminum Sheet

    Science.gov (United States)

    Royster, D. M.; Thomas, J. R.; Singleton, O. R.

    1993-01-01

    Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

  7. Powder metallurgy of turbine disc alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ingesten, N.G. (Dep. of Engineering Metals)

    1981-03-01

    The first part embraced a study of carbide precipitated in IN 100 and astrology powders. The powder was heat treated at temperatures between 950/sup 0/C and 1150/sup 0/C. After aging at 950-1100/sup 0/C the MC-carbides formed during atomization were replaced by M/sub 23/C/sub 6/-carbides. After 1150/sup 0/C treatments the MC carbides were present again. Precipitation comparable with that obtained in HIP:ed specimens was not observed at free particle surfaces. However, powder particles which had agglomerated during atomization often exhibited considerable precipitation at contiguous surfaces. Obviously, contact between the particles must occur if coarse precipitation at particle surfaces is to develop. Reduced PPB-precipitation was obtained by pre-heat- treatment of powder before compaction. It is suggested that the carbon otherwise available for PPB-precipitation forms carbides in the interior of the powder particles. The aim of the second part was to ..gamma..-strengthen a Co-based super-alloy (Co-15Cr-3Mo-5Ti). Here the Ti-addition gives a coherent and ordered ..gamma..-phase Co/sub 3/Ti. However, upon ageing the alloy is unstable in order to increase the stability modifications of the alloy were prepared by: leaving out the Mo-content, adding 10 % Ni and by decreasing the Ti-content to 4.2 %. In addition, the effect of enhanced grain size and of deformation was investigated. Significant reduction of the transformation rate was only obtained by decresing the Ti-content while deformation of the alloy greatly increased the transformation rate.(author).

  8. Sintering of titanium alloy by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Cosme, C.R.M. [Universidade de Brasilia (UnB), DF (Brazil); Henriques, V.A.R.; Cairo, C.A.A.; Taddei, E.B. [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil)

    2009-07-01

    Full text: Titanium alloys are suitable for biomaterial applications, considering its biocompatibility and low elastic modulus compared to steel. Bone resorption in this case can be reduced by load sharing between the implant and natural bone.Starting powders were obtained by hydride method, carried out under positive hydrogen pressure at 500 deg C for titanium and 800 deg C for Nb, Zr and Ta powders. After reaching the nominal temperature, the material was held for 3h, with subsequent cooling to room temperature and milling of the friable hydride. Samples were produce by mixing of initial metallic powders followed by and cold isostatic pressing. Subsequent densification by sintering was performed at temperature range between 900 and 1700 deg C. Characterization was carried out with scanning electron microscopy, X-ray diffractometry and microhardness measurements. Microstructural examinations revealed higher amount of &⧣946;-phase for higher sintering temperature and dissolution of Ta and NB particles. In vitro tests revealed low cytotoxicity of sintered samples. (author)

  9. Powder metallurgy at Savannah River Laboratory

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1978-12-01

    Development of a powder metallurgical process for the manufacture of reactor grade fuel tubes is being carried out at the Savannah River Laboratory (SRL). Using the P/M technology, cores were isostatically compacted with 100 wt % U 3 O 8 and coextruded tubes fabricated which contain up to approx. 80% cores clad with aluminum. Irradiation tests were completed for tubes with up to 59 wt % oxide. Post-irradiation inspection showed no significant swelling for 40% burnup. Thermal testing of sections from irradiated tubes showed that the threshold temperature for blister formation increased as the fission density of oxide decreased. Procedures are discussed for making PM cores and extruded tubes at SRL. Both laboratory and full-scale tests are presented

  10. Development of Cu-Be bronzes through powder metallurgy

    International Nuclear Information System (INIS)

    Abbas, M.

    2012-01-01

    Copper and copper alloys are the major group of commercial alloy. One of the important copper bronzes is Copper beryllium. This is unique among all engineering alloys. Copper beryllium alloy possesses the highest strength in all the copper base alloys. Development of copper beryllium alloy with powder metallurgy is challenging problem due to toxicity of beryllium dust. Purpose of this project to find out parameters by which copper beryllium with all unique properties should obtained. For this purpose efforts are put on development of alternative to copper beryllium system like copper-tin and copper-aluminum by powder metallurgy route. Different time of milling with uniaxial pressure of about 200 MPa and different sintering temperature according to phase diagram of alloy, with different soaking time is tried. Problems may occur like decrease in density after sintering, breaking of samples by Rockwell A, B and C indenters arid by hammering. Cold iso-static pressing at 300 MPa and sintering at above 900 degree C is used to develop copper beryllium alloy. As quenched samples are heat treated at 260 degree C, 315 degree C and 370 degree C with different soaking time of 30, 90 and 180 minutes to find out optimum time and temperature parameters. . It is observed that at aging at 260 degree C for 180 minutes, aging at 315 degree C for 180 minutes and aging at 370 degree C for 30 minutes produce optimum result. By observing these pellets by SEM, precipitates appeared in peak-aged alloy and bigger precipitates in over-aged alloy. Copper beryllium alloy developed through powder metallurgy has better prospects than other copper bronzes. (author)

  11. Properties of porous magnesium prepared by powder metallurgy.

    Science.gov (United States)

    Čapek, Jaroslav; Vojtěch, Dalibor

    2013-01-01

    Porous magnesium-based materials are biodegradable and promising for use in orthopaedic applications, but their applications are hampered by their difficult fabrication. This work reports the preparation of porous magnesium materials by a powder metallurgy technique using ammonium bicarbonate as spacer particles. The porosity of the materials depended on the amount of ammonium bicarbonate and was found to have strong negative effects on flexural strength and corrosion behaviour. However, the flexural strength of materials with porosities of up to 28 vol.% was higher than the flexural strength of non-metallic biomaterials and comparable with that of natural bone. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Copper alloys with improved properties: standard ingot metallurgy vs. powder metallurgy

    Directory of Open Access Journals (Sweden)

    Milan T. Jovanović

    2014-09-01

    Full Text Available Three copper-based alloys: two composites reinforced with Al2O3 particles and processed through powder metallurgy (P/M route, i.e. by internal oxidation (Cu-2.5Al composite and by mechanical alloying (Cu-4.7Al2O3 and Cu-0.4Cr-0.08Zr alloy produced by ingot metallurgy (vacuum melting and casting were the object of this investigation. Light microscope and scanning electron microscope (SEM equipped with electron X-ray spectrometer (EDS were used for microstructural characterization. Microhardness and electrical conductivity were also measured. Compared to composite materials, Cu-0.4Cr-0.08Zr alloy possesses highest electrical conductivity in the range from 20 to 800 ℃, whereas the lowest conductivity shows composite Cu-2.5Al processed by internal oxidation. In spite to somewhat lower electrical conductivity (probably due to inadequate density, Cu-2.5Al composite exhibits thermal stability enabling its application at much higher temperatures than materials processed by mechanical alloying or by vacuum melting and casting.

  13. 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.

  14. Stress analyses of pump gears produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Cetinel, Hakan [Celal Bayar Univ., Mechanical Engineering Dept. (Turkey); Yilmaz, Burak

    2013-06-01

    In this study, trochoidal type (gerotor) hydraulic pump gears were produced by powder metallurgy (P/M) technique. Several gears with different mechanical properties have been obtained by changing process variables. The tooth contact stresses were calculated analytically under particular operation conditions of the hydraulic pump. The 3D models have been obtained from real gears by using Capability Maturity Model (CMM, 3D scanning) operation and SOLIDWORKS software. Stress analyses were conducted on these 3D models by using ANSYS WORKBENCH software. It was found that the density increases by the increase of sintering duration and mechanical properties were positively affected by the increase of density. Maximum deformation takes place in the region of the outer gear where failure generally occurs with the minimum cross-section area.

  15. An application of powder metallurgy for the LHC

    CERN Document Server

    Sgobba, Stefano

    2004-01-01

    The cold mass of the 1232 superconducting dipole magnets of LHC, operating at 1.9 K, is enclosed by a shrinking cylinder and two end covers at its extremities. The covers are structural components that must retain high strength and toughness at cryogenic temperature. They are manufactured by Metso Oy /FI in AISI 316 LN steel by Powder Metallurgy (PM) and Hot Isostatic Pressing. PM represents an attractive near net shaping technique for these components of complex geometry for which dimension tolerances, dimensional stability, weldability are key issues for magnet fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. The material of the covers and its welds have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides result in superior mechanical properties and high ductilit...

  16. N18, powder metallurgy superalloy for disks: Development and applications

    Energy Technology Data Exchange (ETDEWEB)

    Guedou, J.Y.; Lautridou, J.C.; Honnorat, Y. (SNECMA, Evry (France). Materials and Processes Dept.)

    1993-08-01

    The preliminary industrial development of a powder metallurgy (PM) superalloy, designated N18, for disk applications has been completed. This alloy exhibits good overall mechanical properties after appropriate processing of the material. These properties have been measured on both isothermally forged and extruded billets, as well as on specimens cut from actual parts. The temperature capability of the alloy is about 700 C for long-term applications and approximately 750 C for short-term use because of microstructural instability. Further improvements in creep and crack propagation properties, without significant reduction in tensile strength, are possible through appropriate thermomechanical processing, which results in a large controlled grain size. Spin pit tests on subscale disks have confirmed that the N18 alloy has a higher resistance than PM Astrology and is therefore an excellent alloy for modern turbine disk applications.

  17. Powder metallurgy: Solid and liquid phase sintering of copper

    Science.gov (United States)

    Sheldon, Rex; Weiser, Martin W.

    1993-01-01

    Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

  18. Production of titanium alloys for medical implants by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Henriques, V.A.R. [Dept. de Engenharia de Materiais, Faculdade de Engenharia Quimica de Lorena, Lorena SP (Brazil); Silva, C.R.M. da [Div. de Materiais, CTA-IAE-AMR, Sao Jose dos Campos SP (Brazil)

    2001-07-01

    Titanium alloys are expected to be much more widely used for implant materials in the medical and dental fields because of their superior biocompatibility, corrosion resistance and specific strength compared with other metallic implant materials. Vanadium free alloys like Ti-6Al-7Nb and Ti-5Al-2,5Fe have been recently developed for biomedical use. More recently vanadium and aluminum free alloys composed of non-toxic elements like Nb, Ta, Zr and so on with lower modulus have been started to be developed. The {beta} type alloys like Ti-15Mo are now the main target for medical materials. A blended elemental titanium powder metallurgy process has been developed to offer low cost products. The process employs hydride-dehydride (HDH) powders and near-net shape techniques. In this work, the influence of the processing parameters and chemical composition of the elementary powders on the final microstructure was investigated. The alloys were characterized by means of scanning electron microscopy, X-ray diffraction, Vickers microhardness measurements, chemical analysis and density. The results indicate that the samples presented high densification, homogeneous chemical composition and coherent microstructures. The process parameters were defined aiming to reduce the interstitial pick-up (O, N) and to avoid the grain growth. (orig.)

  19. Wear mechanisms in powder metallurgy high speed steels matrix composites

    International Nuclear Information System (INIS)

    Gordo, E.; Martinez, M. A.; Torralba, J. M.; Jimenez, J. A.

    2001-01-01

    The development of metal matrix composites has a major interest for automotive and cutting tools industries since they possess better mechanical properties and wear resistance than corresponding base materials. One of the manufacturing methods for these materials includes processing by powder metallurgy techniques. in this case, blending of both, base material and reinforcement powders constitute the most important process in order to achieve a homogeneous distribution of second phase particles. in the present work, composite materials of M3/2 tool steel reinforced with 2.5,5 and 8 vol% of niobium carbide have been prepared. In order to ensure a homogeneous mix, powders of both materials were mixed by dry high-energy mechanical milling at 200 r.p.m. for 40 h. After a recovering annealing, two routes for consolidate were followed die pressing and vacuum sintering, and hot isostatic pressing (HIP). Pin-on-disc tests were carried out to evaluate wear behaviour in all the materials. Results show that ceramic particles additions improve wear resistance of base material. (Author) 9 refs

  20. Mechanical and microstructural characterization of powder metallurgy CoCrNi medium entropy alloy

    Czech Academy of Sciences Publication Activity Database

    Moravčík, I.; Čížek, Jan; Kováčová, Z.; Nejezchlebová, J.; Kitzmantel, M.; Neubauer, E.; Kuběna, Ivo; Horník, Vít; Dlouhý, I.

    2017-01-01

    Roč. 701, July (2017), s. 370-380 ISSN 0921-5093 Institutional support: RVO:61389021 ; RVO:68081723 Keywords : tensile test * mechanical alloying * plasticity * mechanical characterization * powder metallurgy Subject RIV: JG - Metallurgy; JG - Metallurgy (UFM-A) OBOR OECD: Materials engineering ; Materials engineering (UFM-A) Impact factor: 3.094, year: 2016 https://www.sciencedirect.com/science/article/pii/S0921509317308535

  1. Introduction to powder metallurgy processes for titanium manufacturing; Introduccion al procesado pulvimetalurgico del titanio

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, P. G.; Bolzoni, L.; Ruiz-Navas, E. M.; Gordo, E.

    2011-07-01

    The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.

  2. Superplasticity in powder metallurgy aluminum alloys and composites

    International Nuclear Information System (INIS)

    Mishra, R.S.; Bieler, T.R.; Mukherjee, A.K.

    1995-01-01

    Superplasticity in powder metallurgy Al alloys and composites has been reviewed through a detailed analysis. The stress-strain curves can be put into 4 categories: classical well-behaved type, continuous strain hardening type, continuous strain softening type and complex type. The origin of these different types of is discussed. The microstructural features of the processed material and the role of strain have been reviewed. The role of increasing misorientation of low angle boundaries to high angle boundaries by lattice dislocation absorption is examined. Threshold stresses have been determined and analyzed. The parametric dependencies for superplastic flow in modified conventional aluminum alloys, mechanically alloyed alloys and Al alloy matrix composites is determined to elucidate the superplastic mechanism at high strain rates. The role of incipient melting has been analyzed. A stress exponent of 2, an activation energy equal to that for grain boundary diffusion and a grain size dependence of 2 generally describes superplastic flow in modified conventional Al alloys and mechanically alloyed alloys. The present results agree well with the predictions of grain boundary sliding models. This suggests that the mechanism of high strain rate superplasticity in the above-mentioned alloys is similar to conventional superplasticity. The shift of optimum superplastic strain rates to higher values is a consequence of microstructural refinement. The parametric dependencies for superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of 313 kJ/mol best describes the composites having SiC reinforcements. The role of shape of the reinforcement (particle or whisker) and processing history is addressed. The analysis suggests that the mechanism for superplasticity in composites is interface diffusion controlled grain boundary sliding

  3. Corrosion inhibition of powder metallurgy Mg by fluoride treatments.

    Science.gov (United States)

    Pereda, M D; Alonso, C; Burgos-Asperilla, L; del Valle, J A; Ruano, O A; Perez, P; Fernández Lorenzo de Mele, M A

    2010-05-01

    Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1M KF solution treatments, 0.1M FST and 1M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F(-) treatments. The corrosion inhibitory action of 0.1M FST and 1M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1M FST showed the presence of KMgF(3) crystals on the surface while a MgF(2) film was detected for 1M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F(-)-containing film which ensures the gradual degradation process. Copyright (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Development of new metal matrix composite electrodes for electrical discharge machining through powder metallurgy process

    Directory of Open Access Journals (Sweden)

    C. Mathalai Sundaram

    2014-12-01

    Full Text Available Electrical discharge machining (EDM is one of the widely used nontraditional machining methods to produce die cavities by the erosive effect of electrical discharges. This method is popular due to the fact that a relatively soft electrically conductive tool electrode can machine hard work piece. Copper electrode is normally used for machining process. Electrode wear rate is the major drawback for EDM researchers. This research focus on fabrication of metal matrix composite (MMC electrode by mixing copper powder with titanium carbide (TiC and Tungsten carbide (WC powder through powder metallurgy process, Copper powder is the major amount of mixing proportion with TiC and WC. However, this paper focus on the early stage of the project where powder metallurgy route was used to determine suitable mixing time, compaction pressure and sintering and compacting process in producing EDM electrode. The newly prepared composite electrodes in different composition are tested in EDM for OHNS steel.

  5. Powder Metallurgy Preparation of Co-Based Alloys for Biomedical Applications

    Czech Academy of Sciences Publication Activity Database

    Marek, I.; Novák, P.; Mlynár, J.; Vojtěch, D.; Kubatík, Tomáš František; Málek, J.

    2015-01-01

    Roč. 128, č. 4 (2015), s. 597-601 ISSN 0587-4246. [International Symposium on Physics of Materials (ISPMA) /13./. Prague, 31.08.2014-04.09.2014] Institutional support: RVO:61389021 Keywords : powder metallurgy * mechanical properties * biomedical applications Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 0.525, year: 2015

  6. Mechanical properties of modified low cobalt powder metallurgy Udimet 700 type alloys

    Science.gov (United States)

    Harf, Fredric H.

    1989-01-01

    Eight superalloys derived from Udimet 700 were prepared by powder metallurgy, hot isostatically pressed, heat treated and their tensile and creep rupture properties determined. Several of these alloys displayed properties superior to those of Udimet 700 similarly prepared, in one case exceeding the creep rupture life tenfold. Filter clogging by extracted gamma prime, its measurement and significance are discussed in an appendix.

  7. Microstructural and mechanical properties of biodegradable iron foam prepared by powder metallurgy

    Czech Academy of Sciences Publication Activity Database

    Čapek, Jaroslav; Vojtěch, D.; Oborná, A.

    2015-01-01

    Roč. 83, Oct (2015), s. 468-482 ISSN 0261-3069 R&D Projects: GA ČR GBP108/12/G043 Institutional support: RVO:68378271 Keywords : powder metallurgy * metallic foams * biodegradable iron * mechanical properties * scaffolds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.997, year: 2015

  8. Powder metallurgy approaches to high temperature components for gas turbine engines

    Science.gov (United States)

    Probst, H. B.

    1974-01-01

    Research is reported for the tensile strength, ductility, and heat performance characterisitics of powder metallurgy (p/m) superalloys. Oxide dispersion strengthened alloys were also evaluated for their strength during thermal processing. The mechanical attributes evident in both p/m supperalloys and dispersion strengthened alloys are discussed in terms of research into their possible combination.

  9. [Concomitant influence of occupational and social risk factors on health of workers engaged into powder metallurgy].

    Science.gov (United States)

    Shur, P Z; Zaĭtseva, N V; Kostarev, V G; Lebedeva-Nesevria, N A; Shliapnikov, D M

    2012-01-01

    Results of health risk evaluation in workers engaged into powder metallurgy, using complex of hygienic, medical, epidemiologic and sociologic studies, enable to define priority occupational and social risk factors, to assess degree of their influence on the workers' health and to identify occupationally induced diseases.

  10. Production of a low young modulus titanium alloy by powder metallurgy

    OpenAIRE

    Santos,Dalcy Roberto dos; Henriques,Vinicius André Rodrigues; Cairo,Carlos Alberto Alves; Pereira,Marcelo dos Santos

    2005-01-01

    Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH) powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a prom...

  11. Investigation of a thermoplastic-powder metallurgy process for the fabrication of porous niobium rods

    International Nuclear Information System (INIS)

    Nordin, D.R.

    1978-06-01

    The feasibility of using a thermoplastic-powder metallurgy technique for the fabrication of porous niobium rods was investigated. Some early problems were overcome to successfully extrude the polymer coated niobium powder into long lengths. The effects of certain process variables were investigated. Residual porosity and extrusion pressure were found to be regulated by the polymer fraction. The procedures for taking the extruded polystyrene--niobium rods through the heat treatments to the final, tin infiltrated stage are explained

  12. Structural and electrical properties of copper-nickel-aluminum alloys obtained by conventional powder metallurgy method

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Silveira, C.R. da; Pertile, H.K.S., E-mail: fisica.cch@mackenzie.br [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica; Silva, L.C.E. da; Buso, S.J., E-mail: jgcarrio@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780 deg C) and convenient homogenization treatments (500 deg C for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples. (author)

  13. Structural and electrical properties of copper-nickel-aluminum alloys obtained by conventional powder metallurgy method

    International Nuclear Information System (INIS)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Silveira, C.R. da; Pertile, H.K.S.

    2009-01-01

    This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780 deg C) and convenient homogenization treatments (500 deg C for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples. (author)

  14. Quantifying the properties of low-cost powder metallurgy titanium alloys

    International Nuclear Information System (INIS)

    Bolzoni, L.; Ruiz-Navas, E.M.; Gordo, E.

    2017-01-01

    The extensive industrial employment of titanium is hindered by its high production costs where reduction of these costs can be achieved using cheap alloying elements and appropriate alternative processing techniques. In this work the feasibility of the production of low-cost titanium alloys is addressed by adding steel to pure titanium and processing the alloys by powder metallurgy. In particular, a spherical 4140 LCH steel powder commonly used in metal injection moulding is blended with irregular hydride-dehydride Ti. The new low-cost alloys are cold uniaxially pressed and sintered under high vacuum and show comparable properties to other wrought-equivalent and powder metallurgy titanium alloys. Differential thermal analysis and X-ray diffraction analyses confirm that Ti can tolerate the employment of iron as primary alloying element without forming detrimental TiFe-based intermetallic phases. Thus, the newly designed α+β alloys could be used for cheaper non-critical components.

  15. Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

    Science.gov (United States)

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2015-06-01

    Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 μm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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

  17. Method for forming biaxially textured articles by powder metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2002-01-01

    A method of preparing a biaxially textured alloy article comprises the steps of preparing a mixture comprising Ni powder and at least one powder selected from the group consisting of Cr, W, V, Mo, Cu, Al, Ce, YSZ, Y, Rare Earths, (RE), MgO, CeO.sub.2, and Y.sub.2 O.sub.3 ; compacting the mixture, followed by heat treating and rapidly recrystallizing to produce a biaxial texture on the article. In some embodiments the alloy article further comprises electromagnetic or electro-optical devices and possesses superconducting properties.

  18. Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

    Science.gov (United States)

    Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

    2016-01-26

    A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening.

  19. Mechanical properties of metals for biomedical applications using powder metallurgy process: A review

    Science.gov (United States)

    Dewidar, Montasser Marasy; Yoon, Ho-Chel; Lim, Jae Kyoo

    2006-06-01

    The uses of biomaterials have been revolutionizing the biomedical field in deployment as implants for humans. During the past five decades, many implant materials made of metals have been put into practical use. Powder metallurgy techniques have been used to produce controlled porous structures, such as porous coatings applied for dental and orthopedic surgical implants, which allow bony tissue ingrowth within the implant surface, thereby improving fixation. This paper examines various important metals using powder metallurgy technology to produce elements of a total hip replacement. These alloys are 316L stainless steel alloy, Co-Cr-Mo alloy, and Ti-6Al-4V alloy. Also, this paper examines current information on the mechanical properties. Mechanical properties are discussed as a function of type of materials and process of fabrication. This article addresses the engineering aspects concerning the advantages and disadvantages of each type of material.

  20. U3O8 from resin for powder-metallurgy fabrication of reactor fuel

    International Nuclear Information System (INIS)

    Mosley, W.C. Jr.

    1982-01-01

    A study was conducted to determine if cation exchange resin could be used to produce U 3 O 8 powder suitable for use in powder metallurgy fabrication of fuel tubes for production reactors at the Savannah River Plant (SRP). U 3 O 8 powders have been produced from three cation exchange resins: DOWEX (Dow Chemical Co.) 50W, AG (Bio-Rad Laboratories, Richmond, California) MP-50, and Bio-REX (Bio-Rad Laboratories, Richmond, California). This study included characterization of the thermal decomposition of uranium-loaded resins, measurement of properties of resin-based U 3 O 8 powders, and metallographic examination of U 3 O 8 -Al cores in extruded fuel tubes. Results to date show that AG MP-50 appears to be the best resin for producing U 3 O 8 powder suitable for the PM process. 20 figures

  1. Characterization of Powder Metallurgy Processed Pure Magnesium Materials for Biomedical Applications

    Czech Academy of Sciences Publication Activity Database

    Březina, M.; Minda, J.; Doležal, P.; Krystýnová, M.; Fintová, Stanislava; Zapletal, J.; Wasserbauer, J.; Ptáček, P.

    2017-01-01

    Roč. 7, č. 11 (2017), č. článku 461. ISSN 2075-4701 Institutional support: RVO:68081723 Keywords : magnesium * powder metallurgy * cold pressing * hot pressing * EIS (Electrochemical impedance spectroscopy) * three-point bending test * corrosion Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films Impact factor: 1.984, year: 2016 http://www.mdpi.com/2075-4701/7/11/461

  2. Production of titanium alloys for advanced aerospace systems by powder metallurgy

    OpenAIRE

    Henriques, Vinicius André Rodrigues; Campos, Pedro Paulo de; Cairo, Carlos Alberto Alves; Bressiani, José Carlos

    2005-01-01

    Titanium alloys parts are ideally suited for advanced aerospace systems because of their unique combination of high specific strength at both room temperature and moderately elevated temperature, in addition to excellent corrosion resistance. Despite these features, use of titanium alloys in engines and airframes is limited by cost. The alloys processing by powder metallurgy eases the obtainment of parts with complex geometry. In this work, results of the Ti-6Al-4V and Ti-13Nb-13Zr alloys pro...

  3. A Comparison of the Plastic Flow Response of a Powder Metallurgy Nickel Base Superalloy (Postprint)

    Science.gov (United States)

    2017-04-01

    Materials The nickel-base, powder-metallurgy (PM) cc¢ super- alloy LSHR was used to establish the effect of test method on plastic -flow response under hot...of friction was estimated to lead to maximum errors in flow stress of the order of 3 pct for the sample geometry and height reduction used in the... plastic -flow behavior of LSHR (in effective stress-strain terms) was described using a phenomeno- logical relationship typical of those for

  4. Review of some past and present powder metallurgy programs at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Sheinberg, H.

    1977-01-01

    Powder metallurgy programs at LASL are reviewed. Topics covered include: KIWI reactor fuel elements; Phoebus reactor fuel elements, criticality control and poison plate material, structural composites for fuel element supports, and heat shields for fuel element supports; thermionic emitter reactor uranium carbide--zirconium carbide fuel pins, and molybdenum--uranium oxide fuel pins; laser and electron beam fusion targets; and current work in MHD components

  5. A Nonvolume Preserving Plasticity Theory with Applications to Powder Metallurgy

    Science.gov (United States)

    Cassenti, B. N.

    1983-01-01

    A plasticity theory has been developed to predict the mechanical response of powder metals during hot isostatic pressing. The theory parameters were obtained through an experimental program consisting of hydrostatic pressure tests, uniaxial compression and uniaxial tension tests. A nonlinear finite element code was modified to include the theory and the results of themodified code compared favorably to the results from a verification experiment.

  6. Making Self-Lubricating Parts By Powder Metallurgy

    Science.gov (United States)

    Sliney, Harold E.; Dellacorte, Christopher

    1990-01-01

    Compositions and parameters of powder-metallurgical fabrication processes determined for new class of low-friction, low-wear, self-lubricating materials. Used in oxidizing or reducing atmospheres in bearings and seals, at temperatures from below 25 degrees C to as high as 900 degrees C. Thick parts made with minimal waste.

  7. Effect of repressing on the mechanical properties of the valve guides manufactured by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Andrés Rodríguez-Spitia

    2017-03-01

    Full Text Available Characterization of hardness, mass loss, and friction coefficient, was carried out on valve guides for internal combustion engines, manufactured by powder metallurgy, with the aim of finding out if they fulfill the requirements of an internal combustion engine and to be mass produced. Currently available brass casting valve guides were used as comparative parameter. It was analyzed whether properties were present in a homogeneous way in the piece lengthwise; the additional repressing process carried out in the production line with respect to the sintered guides was evaluated. Therefore, Brinell, Vickers and dry slip pin-on-disk tests were done in order to determine the friction coefficient and the wear rate. Scanning electron microscopy SEM and the metallographic analysis were used to study the wear mechanism, chemical composition of the guides, and the effect of repressing -quantifying the porosity. It was clear that these pieces manufactured by powder metallurgy process showed lower values in their mechanical-tribological properties compared to commercially available valve guides taken as reference. With these results, the company which manufactures the guides by powder metallurgy will make some adjustments suggested for the parameters at the guide’s production line.

  8. Manufacture of good-weldable low oxygen molybdenum by powder metallurgy

    International Nuclear Information System (INIS)

    Hiraoka, Yutaka; Okada, Masatoshi; Akiyama, Takashi; Yamafuchi, Yasuo.

    1984-01-01

    In general most of commercial molybdenum is produced by the powder metallurgy method and is utilized as a superior heat-resisting material in many fields. Moreover, molybdenum is expected to be used as the first-wall components of JT-60 (JAERI Tokamak-60). However, one of major problems on molybdenum, particularly on powder metallurgy molybdenum, is that any sound welded joint is hard to be obtainable. In many cases weld pores are formed on welding and, therefore, ductility of the welded joint is severely degraded. The object of the present work is to get a sound welded joint without any weld pores by reducing impurity levels in the material. The materials were produced by modifying one or several parts in the ordinary manufacturing process of powder metallurgy molybdenum. Oxygen, nitrogen, carbon and other principal metallic impurities were chemically analysed. The above materials were then subjected to electron-beam-welding by using a melt-run technique, and the soundness of the welded joints was examined by optical microscopy. (author)

  9. Investment casting or powder metallurgy – the ecological aspect

    Directory of Open Access Journals (Sweden)

    J. Tomasik

    2009-04-01

    Full Text Available The paper presents an analysis of manufacturing methods of material-saving products in relation to investment castings and sinteredpowder technology. Surface microgeometry, shape accuracy, performance parameters, manufacturing costs and energy consumption weretaken into account to make the optimal choice. The analysis was conducted by comparing test results for sintered powder products basedon Distaloy AB alloy that consists of 0.55% C, 1.5% Cu, 1.75% Ni and 0.5% Mo and investment castings made of high alloy cast steel andnodular cast iron. The analysis made it possible to choose the best technology, considering also the ecological aspect.

  10. Powder metallurgy processing and deformation characteristics of bulk multimodal nickel

    Energy Technology Data Exchange (ETDEWEB)

    Farbaniec, L., E-mail: lfarban1@jhu.edu [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Dirras, G., E-mail: dirras@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Krawczynska, A.; Mompiou, F. [Université Paul Sabatier, CEMES, CNRS, 29 rue Jeanne Marvig 31055 Toulouse (France); Couque, H. [Nexter Munitions, 7 route de Guerry, 18200 Bourges (France); Naimi, F.; Bernard, F. [Institut Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne, BP 47870, 21078 Dijon (France); Tingaud, D. [Université Paris 13, Sorbonne Paris Cité, LSPM, CNRS, 99 Avenue J.B. Clément, 93430 Villetaneuse (France)

    2014-08-15

    Spark plasma sintering was used to process bulk nickel samples from a blend of three powder types. The resulting multimodal microstructure was made of coarse (average size ∼ 135 μm) spherical microcrystalline entities (the core) surrounded by a fine-grained matrix (average grain size ∼ 1.5 μm) or a thick rim (the shell) distinguishable from the matrix. Tensile tests revealed yield strength of ∼ 470 MPa that was accompanied by limited ductility (∼ 2.8% plastic strain). Microstructure observation after testing showed debonding at interfaces between the matrix and the coarse entities, but in many instances, shallow dimples within the rim were observed indicating local ductile events in the shell. Dislocation emission and annihilation at grain boundaries and twinning at crack tip were the main deformation mechanisms taking place within the fine-grained matrix as revealed by in-situ transmission electron microscopy. Estimation of the stress from loop's curvature and dislocation pile-up indicates that dislocation emission from grain boundaries and grain boundary overcoming largely contributes to the flow stress. - Highlights: • Bulk multi-modal Ni was processed by SPS from a powder blend. • Ultrafine-grained matrix or rim observed around spherical microcrystalline entities • Yield strength (470 MPa) and ductility (2.8% plastic strain) were measured. • Debonding was found at the matrix/microcrystalline entity interfaces. • In-situ TEM showed twinning, dislocation emission and annihilation at grain boundaries.

  11. Powder metallurgy processing of high strength turbine disk alloys

    Science.gov (United States)

    Evans, D. J.

    1976-01-01

    Using vacuum-atomized AF2-1DA and Mar-M432 powders, full-scale gas turbine engine disks were fabricated by hot isostatically pressing (HIP) billets which were then isothermally forged using the Pratt & Whitney Aircraft GATORIZING forging process. While a sound forging was produced in the AF2-1DA, a container leak had occurred in the Mar-M432 billet during HIP. This resulted in billet cracking during forging. In-process control procedures were developed to identify such leaks. The AF2-1DA forging was heat treated and metallographic and mechanical property evaluation was performed. Mechanical properties exceeded those of Astroloy, one of the highest temperature capability turbine disk alloys presently used.

  12. Microstructural and electrical investigation of Cu-Ni-Cr alloys obtained by powder metallurgy method

    Energy Technology Data Exchange (ETDEWEB)

    Carrio, Juan A.G.; Carvalhal, M.A.; Ayabe, L.M.; Monteiro, W.A., E-mail: jgcarrio@mackenzie.br [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica; Silva, L.C.E. da; Silva Junior, R.V., E-mail: fisica.cch@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The aim of this work, using the powder metallurgy process, is to synthesize metallic alloys with high mechanical strength and high electric conductivity, after melting optimizing and thermal treatments. The Cu-Ni-Cr (wt%) alloys are characterized in their mechanical and electrical properties as well as the obtained microstructure. Through the process of powder metallurgy, contacts and structural parts can be obtained. The alloys elements are added to copper with the intention to improve their strength, ductility and thermal stability, without causing considerable damages in their form, electrical and thermal conductivity, and corrosion resistance. The metallic powders were mixed for a suitable time and then they were pressed in a cold uniaxial pressing (1000 kPa). Afterwards, the specimens were sintered in temperatures varying from 700 up to 800 deg C under vacuum. At last, the samples were homogenized at 550 deg C under vacuum, for special times. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. The alloys were characterized by optical microscopy, X-rays powder diffraction, electrical conductivity and Vickers hardness. (author)

  13. Microstructure and microanalysis studies of copper-nickel-tin alloys obtained by conventional powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Masson, T.J.; Vitor, E.; Abreu, C.D.; Marques, I.M., E-mail: fisica.cch@mackenzie.br [Universidade Presbiteriana Mackenzie (CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades; Silva, L.C.E. da, E-mail: jgcarrio@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The aim of this paper was to analyze the microstructural development in samples of Cu-Ni-Sn alloys (weight %) obtained by powder metallurgy (P/M). The powders were mixed for 1/2 hour. After this, they were pressed, in a cold uniaxial pressing (1000 kPa). In the next step the specimens were sintered at temperatures varying from 650 up to 780 deg C under vacuum. Secondly, the samples were homogenized at 500 deg C for several special times. The alloys were characterized by optical microscopy, electrical conductivity and Vickers hardness. X-rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. (author)

  14. Powder-metallurgy preparation of NiTi shape-memory alloy using mechanical alloying and spark-plasma sintering.

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Moravec, H.; Vojtěch, V.; Knaislová, A.; Školáková, A.; Kubatík, Tomáš František; Kopeček, Jaromír

    2017-01-01

    Roč. 51, č. 1 (2017), s. 141-144 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : mechanical alloying * spark plasma sintering * NiTi * shape memory alloy Subject RIV: JG - Metallurgy; JG - Metallurgy (FZU-D) OBOR OECD: Materials engineering ; Materials engineering (FZU-D) Impact factor: 0.436, year: 2016 https://www.researchgate.net/publication/313900224_Powder-metallurgy_preparation_of_NiTi_shape-memory_alloy_using_mechanical_alloying_and_spark-plasma_sintering

  15. Thermal stability and creep behaviour of MgNiYCe-rich mischmetal alloys processed by a powder metallurgy route

    Czech Academy of Sciences Publication Activity Database

    Peréz, P.; Milička, Karel; Badia, J. M.; Garcés, G.; Antoranz, J. M.; Gonzáles, S.; Dobeš, Ferdinand; Adeva, P.

    289-292, - (2009), s. 127-136 ISSN 1012-0386. [DIMAT 2008, International Conference on Diffusion in Materials /7./. Lanzarote, Canary Islands, 28.10.2008-31.10.2008] Grant - others:Ministerio de Ciencia y Tecnologia (ES) MAT2006-11731-C02 Institutional research plan: CEZ:AV0Z20410507 Keywords : magnesium alloys * powder metallurgy * microstructure * thermal stability * creep Subject RIV: JG - Metallurgy

  16. Acoustic harmonic generation measurement applications: Detection of tight cracks in powder metallurgy compacts

    International Nuclear Information System (INIS)

    Barnard, D.J.; Foley, J.C.

    2000-01-01

    Standard linear ultrasonic testing techniques have long been employed for locating and characterizing relatively open cracks in a wide variety of materials, from metallic alloys and ceramics to composites. In all these materials, the detection of open cracks easily accomplished because the void between the two crack surfaces provides sufficient acoustic impedance mismatch to reflect the incident energy. Closed or partially closed cracks, however, may often go undetected because contacting interfaces allow transmission of ultrasound. In the green (unsintered) state, powder metallurgy compacts typically contain high residual stresses that have the ability to close cracks formed during the compaction process, a result of oxide films, improper powder lubricant, mold design, etc. After sintering, the reduction of residual stresses may no longer be sufficient to close the crack. Although the crack may be more easily detected, it is obvious most desirable to discover defects prior to sintering. It has been shown that the displacements of an interface may be highly nonlinear if a stress wave of sufficient intensity propagates across it, a result of the stress wave either opening or closing the interface. Current efforts involve the application of nonlinear acoustic techniques, in particular acoustic harmonic generation measurements, for the detection and characterization of tightly closed cracks in powder metallurgy parts. A description of the equipment and the measurement technique will be discussed and initial experimental results on sintered and green compacts will be presented. - This work was performed at the Ames Laboratory, Iowa State University under USDOE Contract No. W-7405-ENG-82

  17. Characterization of aluminum/steel components from recycled swarf using the powder metallurgy as technique

    International Nuclear Information System (INIS)

    Souza, V.E.S.; Masieiro, F.R.S.; Lourenco, J.M.; Felipe, R.C.T.S.

    2009-01-01

    Full text: The powder metallurgy process consists to produce metallic or ceramic components through pressure in a powder mass. These components will be submitted to a sintering temperature in order to consolidate them and then improve their mechanical proprieties. The industry is responsible for the swarf generation from different manufacture process. This paper has main goal the reutilization of aluminum and steel swarf using the powder metallurgy as technique. The methodology used in this work consists to compact Al 6060 plus steel SAE 1045 as reinforce material at 250MPa, 400MPa and 600MPa. The composition about these compacted will be 30%, 40%, 50% of steel into aluminum matrix. In this way will be analyze the hardness as function of the compressibility and quantity of steel. The samples will be processed at 500°C during 45 minutes using a resistive furnace in a hydrogen atmosphere. Micrographs of the sintered samples will be obtained by using a Scanning Electron Microscope and Optic Microscope. X-rays diffraction will be also used to characterize the phases found to due diffusivity between the steel and aluminum. (author)

  18. Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

    Science.gov (United States)

    Piascik, Robert S.; Newman, John A.

    2002-01-01

    Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

  19. Modeling of wear behavior of Al/B{sub 4}C composites produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Ismail; Bektas, Asli [Gazi Univ., Ankara (Turkey). Dept. of Industrial Design Engineering; Guel, Ferhat; Cinci, Hanifi [Gazi Univ., Ankara (Turkey). Dept. of Materials and Metallurgy Engineering

    2017-06-01

    Wear characteristics of composites, Al matrix reinforced with B{sub 4}C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B{sub 4}C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

  20. Modeling of wear behavior of Al/B4C composites produced by powder metallurgy

    International Nuclear Information System (INIS)

    Sahin, Ismail; Bektas, Asli; Guel, Ferhat; Cinci, Hanifi

    2017-01-01

    Wear characteristics of composites, Al matrix reinforced with B 4 C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B 4 C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

  1. The synthesis and characterization of Mg-Zn-Ca alloy by powder metallurgy process

    Energy Technology Data Exchange (ETDEWEB)

    Annur, Dhyah; Franciska, P.L.; Erryani, Aprilia; Amal, M. Ikhlasul; Kartika, Ika, E-mail: pepeng2000@yahoo.com [Research center for Metallurgy and Material, Indonesian Institute of Science (Indonesia); Sitorus, Lyandra S. [Sultan Ageng Tirtayasa University (Indonesia)

    2016-04-19

    Known for its biodegradation and biocompatible properties, magnesium alloys have gained many interests to be researched as implant material. In this study, Mg-3Zn-1Ca, Mg-29Zn-1Ca, and Mg-53Zn-4.3Ca (in wt%) were synthesized by means of powder metallurgy method. The compression strength and corrosion resistance of magnesium alloy were thoroughly examined. The microstructures of the alloy were characterized using optical microscopy, Scanning Electron Microscope, and also X-ray diffraction analysis. The corrosion resistance were evaluated using electrochemical analysis. The result indicated that Mg- Zn- Ca alloy could be synthesized using powder metallurgy method. This study showed that Mg-29Zn-1Ca would make the highest mechanical strength up to 159.81 MPa. Strengthening mechanism can be explained by precipitation hardening and grain refinement mechanism. Phase analysis had shown the formation of α Mg, MgO, and intermetallic phases: Mg2Zn11 and also Ca2Mg6Zn3. However, when the composition of Zn reach 53% weight, the mechanical strength will be decreasing. In addition, all of Mg-Zn-Ca alloy studied here had better corrosion resistance (Ecorr around -1.4 VSCE) than previous study of Mg. This study indicated that Mg- 29Zn- 1Ca alloy can be further analyzed to be a biodegradable implant material.

  2. Development of processes for zircaloy chips recycling by electric arc furnace remelting and powder metallurgy

    International Nuclear Information System (INIS)

    Pereira, Luiz Alberto Tavares

    2014-01-01

    PWR reactors employ, as nuclear fuel, UO 2 pellets with Zircaloy clad. In the fabrication of fuel element parts, machining chips from the alloys are generated. As the Zircaloy chips cannot be discarded as ordinary metallic waste, the recycling of this material is important for the Brazilian Nuclear Policy, which targets the reprocess of Zircaloy residues for economic and environmental aspects. This work presents two methods developed in order to recycle Zircaloy chips. In one of the methods, Zircaloy machining chips were refused using an electric-arc furnace to obtain small laboratory ingots. The second one uses powder metallurgy techniques, where the chips were submitted to hydriding process and the resulting material was milled, isostatically pressed and vacuum sintered. The ingots were heat-treated by vacuum annealing. The microstructures resulting from both processing methods were characterized using optical and scanning electron microscopy. Chemical composition, crystal phases and hardness were also determined. The results showed that the composition of recycled Zircaloy comply with the chemical specifications and presented adequate microstructure for nuclear use. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding end-caps, using near net shape sintering. (author)

  3. Development of an extra-high strength powder metallurgy nickel-base superalloy

    Science.gov (United States)

    Kent, W. B.

    1977-01-01

    A program was conducted to optimize the composition of NASA IIb-11, an alloy originally developed as a wrought material, for thermal stability and to determine the feasibility for producing the alloy using powder metallurgy techniques. Seven compositions were melted and atomized, hot isostatically pressed, cross rolled to disks and heat treated. Tensile and stress rupture properties from room temperature to 870 C (1600 F) were determined in addition to thermal stability characteristics. Processing variables included hot isostatic pressing parameters and handling, cross rolling procedures and heat treatment cycles. NASA IIb-11E displayed the best combination of overall properties for service as a 760 C (1400 F) disk material. Its composition is 0.06 C, 8.5 Cr, 9.0 Co, 2.0 Mo, 7.1 W, 6.6 Ta, 4.5 Al, 0.75 Ti, 0.5 V, 0.7 Hf, 0.01 B, 0.05 Zr and balance Ni. While the alloy exhibits the highest 760 C (1400 F) rupture strength reported for any powder metallurgy disk alloy to date, additional studies to further evaluate the effects of heat treatment may be required. The alloy is not susceptible to topologically close-packed phase formation during thermal exposure at 870 C (1600 F) for 1,500 hours, but its mechanical property levels are lowered due to grain boundary carbide formation.

  4. Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

    Science.gov (United States)

    Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

    2008-09-01

    One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

  5. Microstructural and mechanical characteristics of porous iron prepared by powder metallurgy.

    Science.gov (United States)

    Capek, Jaroslav; Vojtěch, Dalibor

    2014-10-01

    The demand for porous biodegradable load-bearing implants has been increasing recently. Based on investigations of biodegradable stents, porous iron may be a suitable material for such applications. In this study, we prepared porous iron samples with porosities of 34-51 vol.% by powder metallurgy using ammonium bicarbonate as a space-holder material. We studied sample microstructure (SEM-EDX and XRD), flexural and compressive behaviors (universal loading machine) and hardness HV5 (hardness tester) of the prepared samples. Sample porosity increased with the amount of spacer in the initial mixtures. Only the pore surfaces had insignificant oxidation and no other contamination was observed. Increasing porosity decreased the mechanical properties of the samples; although, the properties were still comparable with human bone and higher than those of porous non-metallic biomaterials and porous magnesium prepared in a similar way. Based on these results, powder metallurgy appears to be a suitable method for the preparation of porous iron for orthopedic applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Study on the formation of cubic texture in Ni-7 at.% W alloy substrates by powder metallurgy routes

    DEFF Research Database (Denmark)

    Zhao, Yue; Suo, HongLi; Zhu, YongHua

    2009-01-01

    One of the main challenges for coated conductor applications is to produce sharp cubic textured alloy substrates with high strength and low magnetism. In this work, the cubic textured Ni–7 at.% W substrates were prepared from different powder metallurgy ingots by rolling-assisted biaxially textured...... substrate processing. The fabrication processes of cubic texture in the Ni–7 at.% W tapes by two powder metallurgy routes are described in detail. Through the optimized process, full width at half maximum values of 6.7° and 5.0° were obtained, as estimated by X-ray (1 1 1) phi scan and (2 0 0) rocking curve...

  7. Innovative technologies for powder metallurgy-based disk superalloys: Progress and proposal

    Science.gov (United States)

    Chong-Lin, Jia; Chang-Chun, Ge; Qing-Zhi, Yan

    2016-02-01

    Powder metallurgy (PM) superalloys are an important class of high temperature structural materials, key to the rotating components of aero engines. In the purview of the present challenges associated with PM superalloys, two novel approaches namely, powder preparation and the innovative spray-forming technique (for making turbine disk) are proposed and studied. Subsequently, advanced technologies like electrode-induction-melting gas atomization (EIGA), and spark-plasma discharge spheroidization (SPDS) are introduced, for ceramic-free superalloy powders. Presently, new processing routes are sought after for preparing finer and cleaner raw powders for disk superalloys. The progress of research in spray-formed PM superalloys is first summarized in detail. The spray-formed superalloy disks specifically exhibit excellent mechanical properties. This paper reviews the recent progress in innovative technologies for PM superalloys, with an emphasis on new ideas and approaches, central to the innovation driving techniques like powder processing and spray forming. Project supported by the National Natural Science Foundation of China (Grant Nos. 50974016 and 50071014).

  8. Fabrication of Fe-Cr-Mo powder metallurgy steel via a mechanical-alloying process

    Science.gov (United States)

    Park, Jooyoung; Jeong, Gowoon; Kang, Singon; Lee, Seok-Jae; Choi, Hyunjoo

    2015-11-01

    In this study, we employed a mechanical-alloying process to manufacture low-alloy CrL and CrM steel powders that have similar specifications to their water-atomized counterparts. X-ray diffraction showed that Mo and Cr are alloyed in Fe after four cycles of planetary milling for 1 h at 150 RPM with 15-min pauses between the cycles (designated as P2C4 process). Furthermore, the measured powder size was found to be similar to that of the water-atomized counterparts according to both scanning electron microscope images and laser particle size analysis. The samples were sintered at 1120 °C, after which the P2C4-milled CrL showed similar hardness to that of water-atomized CrL, whereas the P2C4-milled CrM showed about 45% lower hardness than that of its water-atomized counterpart. Water-atomized CrM consists of a well-developed lathtype microstructure (bainite or martensite), while a higher fraction of polygonal ferrite is observed in P2C4-milled CrM. This phase difference causes the reduction of hardness in the P2C4-milled CrM, implying that the phase transformation behavior of specimens produced via powder metallurgy is influenced by the powder fabrication method.

  9. The Promotion of Liquid Phase Sintering of Boron-Containing Powder Metallurgy Steels by Adding Nickel

    Directory of Open Access Journals (Sweden)

    Wu Ming-Wei

    2015-01-01

    Full Text Available Boron is a feasible alloying element for liquid phase sintering (LPS of powder metallurgy (PM steels. This study investigated the effect of nickel (Ni, which is widely used in PM steels, on the liquid phase sintering of boron-containing PM steels. The results showed that the addition of 1.8wt% Ni does not apparently modify the LPS mechanism of boron-containing PM steels. However, adding 1.8wt% Ni slightly improves the LPS densification from 0.60 g/cm3 to 0.65 g/cm3, though the green density is reduced. Thermodynamic simulation demonstrated that the presence of Ni lowers the temperature region of liquid formation, resulting in enhanced LPS densification. Moreover, original graphite powders remains in the steels sintered at 1200 ºC. These graphite powders mostly dissolve into the base iron powder when the sintering temperature is increased from 1200 ºC to 1250 ºC.

  10. Influence of thermo-mechanical processing on the microstructure of Cu-based shape memory alloys produced by powder metallurgy

    International Nuclear Information System (INIS)

    Rodriguez, P.P.; Ibarra, A.; Iza-Mendia, A.; Recarte, V.; Perez-Landazabal, J.I.; San Juan, J.; No, M.L.

    2003-01-01

    Cu-Al-Ni shape memory alloys processed by powder metallurgy show very good thermo-mechanical properties, much better than those found in alloys produced by conventional casting. In this paper, we present the microstructural characterisation of these powder metallurgy alloys in order to find the microscopic mechanisms, linked to the powder metallurgy processing method, which are indeed responsible of such good thermo-mechanical behaviour. Electron microscopy studies [scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM)] show that powder metallurgy processing creates a sub-grain structure characterised by the presence of low angle sub-boundaries. These sub-boundaries are found to be lying on {1 1 0} and {1 1 2} lattice planes and are composed by an arrangement of superdislocations. These sub-boundaries may improve ductility in two ways: acting as a sink of dislocations which promotes plastic deformation and decreasing stress concentration at grain boundaries. Moreover, since sub-boundaries act as weak obstacles for the movement of martensite plates, the improvement on ductility is accomplished by an adequate thermo-mechanical behaviour

  11. Some aspects of barreling in sintered plain carbon steel powder metallurgy preforms during cold upsetting

    Directory of Open Access Journals (Sweden)

    Sumesh Narayan

    2012-04-01

    Full Text Available The present research establishes a relationship of bulged diameter with densification and hydrostatic stress in forming of sintered iron (Fe powder metallurgy preforms cold upset under two different frictional conditions, namely, nil/no and graphite lubricant condition. Sintered plain carbon steel cylindrical preforms with carbon (C contents of 0, 0.35, 0.75 and 1.1% with constant initial theoretical density of 84% and aspect ratio of 0.4 and 0.6 were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 minutes at 1200 °C. Each sintered preform was cold upset under two different frictional constraints. It is seen that the degree of bulging reduces with reducing frictional constraints at the die contact surface. Further, it is found that the bulging ratio changed as a function of relative density and hydrostatic stress, respectively, according to the power law equations.

  12. A powder metallurgy austenitic stainless steel for application at very low temperatures

    CERN Document Server

    Sgobba, Stefano; Liimatainen, J; Kumpula, M

    2000-01-01

    The Large Hadron Collider to be built at CERN will require 1232 superconducting dipole magnets operating at 1.9 K. By virtue of their mechanical properties, weldability and improved austenite stability, nitrogen enriched austenitic stainless steels have been chosen as the material for several of the structural components of these magnets. Powder Metallurgy (PM) could represent an attractive production technique for components of complex shape for which dimension tolerances, dimensional stability, weldability are key issues during fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. PM Hot Isostatic Pressed test plates and prototype components of 316LN-type grade have been produced by Santasalo Powdermet Oy. They have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides ...

  13. Microstructure, mechanical behavior and biocompatibility of powder metallurgy Nb-Ti-Ta alloys as biomedical material.

    Science.gov (United States)

    Liu, Jue; Chang, Lin; Liu, Hairong; Li, Yongsheng; Yang, Hailin; Ruan, Jianming

    2017-02-01

    Microstructures, mechanical properties, apatite-forming ability and in vitro experiments were studied for Nb-25Ti-xTa (x=10, 15, 20, 25, 35at.%) alloys fabricated by powder metallurgy. It is confirmed that the alloys could achieve a relative density over 80%. Meanwhile, the increase in Ta content enhances the tensile strength, elastic modulus and hardness of the as-sintered alloys. When increasing the sintering temperatures, the microstructure became more homogeneous for β phase, resulting in a decrease in the modulus and strength. Moreover, the alloys showed a good biocompatibility due to the absence of cytotoxic elements, and were suitable for apatite formation and cell adhesion. In conclusion, Nb-25Ti-xTa alloys are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Comparison Study on Additive Manufacturing (AM) and Powder Metallurgy (PM) AlSi10Mg Alloys

    Science.gov (United States)

    Chen, B.; Moon, S. K.; Yao, X.; Bi, G.; Shen, J.; Umeda, J.; Kondoh, K.

    2018-02-01

    The microstructural and mechanical properties of AlSi10Mg alloys fabricated by additive manufacturing (AM) and powder metallurgy (PM) routes were investigated and compared. The microstructures were examined by scanning electron microscopy assisted with electron-dispersive spectroscopy. The crystalline features were studied by x-ray diffraction and electron backscatter diffraction. Room-temperature tensile tests and Vickers hardness measurements were performed to characterize the mechanical properties. It was found that the AM alloy had coarser Al grains but much finer Si precipitates compared with the PM alloy. Consequently, the AM alloy showed more than 100% increment in strength and hardness compared with the PM alloy due to the presence of ultrafine forms of Si, while exhibiting moderate ductility.

  15. Fabrication of homogeneously dispersed graphene/Al composites by solution mixing and powder metallurgy

    Science.gov (United States)

    Zeng, Xiang; Teng, Jie; Yu, Jin-gang; Tan, Ao-shuang; Fu, Ding-fa; Zhang, Hui

    2018-01-01

    Graphene-reinforced aluminum (Al) matrix composites were successfully prepared via solution mixing and powder metallurgy in this study. The mechanical properties of the composites were studied using microhardness and tensile tests. Compared to the pure Al alloy, the graphene/Al composites showed increased strength and hardness. A tensile strength of 255 MPa was achieved for the graphene/Al composite with only 0.3wt% graphene, which has a 25% increase over the tensile strength of the pure Al matrix. Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the morphologies, chemical compositions, and microstructures of the graphene and the graphene/Al composites. On the basis of fractographic evidence, a relevant fracture mechanism is proposed.

  16. Production of a low young modulus titanium alloy by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Dalcy Roberto dos Santos

    2005-12-01

    Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

  17. Characterization of Powder Metallurgy Processed Pure Magnesium Materials for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Matěj Březina

    2017-10-01

    Full Text Available Magnesium with its mechanical properties and nontoxicity is predetermined as a material for biomedical applications; however, its high reactivity is a limiting factor for its usage. Powder metallurgy is one of the promising methods for the enhancement of material mechanical properties and, due to the introduced plastic deformation, can also have a positive influence on corrosion resistance. Pure magnesium samples were prepared via powder metallurgy. Compacting pressures from 100 MPa to 500 MPa were used for samples’ preparation at room temperature and elevated temperatures. The microstructure of the obtained compacts was analyzed in terms of microscopy. The three-point bendisng test and microhardness testing were adopted to define the compacts’ mechanical properties, discussing the results with respect to fractographic analysis. Electrochemical corrosion properties analyzed with electrochemical impedance spectroscopy carried out in HBSS (Hank’s Balanced Salt Solution and enriched HBSS were correlated with the metallographic analysis of the corrosion process. Cold compacted materials were very brittle with low strength (up to 50 MPa and microhardness (up to 50 HV (load: 0.025 kg and degraded rapidly in both solutions. Hot pressed materials yielded much higher strength (up to 250 MPa and microhardness (up to 65 HV (load: 0.025 kg, and the electrochemical characteristics were significantly better when compared to the cold compacted samples. Temperatures of 300 °C and 400 °C and high compacting pressures from 300 MPa to 500 MPa had a positive influence on material bonding, mechanical and electrochemical properties. A compacting temperature of 500 °C had a detrimental effect on material compaction when using pressure above 200 MPa.

  18. An investigation of wear behaviors of different Monel alloys produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Esgin, U.; Özyürek, D. [Karabük University, Technology Faculty, Department of Manufacturing Engineering / Karabuk (Turkey); Kaya, H., E-mail: hasan.kaya@kocaeli.edu.tr [Kocaeli University, Asim Kocabiyik Vocational School of Higher Education, Department of Machine / Kocaeli (Turkey)

    2016-04-21

    In the present study, wear behaviors of Monel 400, Monel 404, Monel R-405 and Monel K-500 alloys produced by Powder Metallurgy (P/M) method were investigated. These compounds prepared from elemental powders were cold-pressed (600 MPa) and then, sintered at 1150°C for 2 hours and cooled down to the room temperature in furnace environment. Monel alloys produced by the P/M method were characterized through scanning electron microscope (SEM+EDS), X-ray diffraction (XRD), hardness and density measurements. In wear tests, standard pin-on-disk type device was used. Specimens produced within four different Monel Alloys were tested under 1ms{sup −1} sliding speed, under three different loads (20N, 30N and 40N) and five different sliding distances (400-2000 m). The results show that Monel Alloys have γ matrix and that Al{sub 0,9}Ni{sub 4,22} intermetallic phase was formed in the structure. Also, the highest hardness value was measured with the Monel K-500 alloy. In wear tests, the maximum weight loss according to the sliding distance, was observed in Monel 400 and Monel 404 alloys while the minimum weight loss was achieved by the Monel K-500 alloy.

  19. Compressibility of 304 Stainless Steel Powder Metallurgy Materials Reinforced with 304 Short Stainless Steel Fibers

    Directory of Open Access Journals (Sweden)

    Bibo Yao

    2016-03-01

    Full Text Available Powder metallurgy (P/M technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass ratio. In this paper, the compressive properties of the P/M materials were characterized by a series of uniaxial compression tests. The effects of fiber content, compaction pressure and high temperature nitriding on compressive properties were investigated. The results indicated that, without nitriding, the samples changed from cuboid to cydariform without damage in the process of compression. The compressive stress was enhanced with increasing fiber content ranging from 0 to 8 wt.%. For compaction pressure from 55 to 75 MPa, greater compaction pressure improved compressive stress. Moreover, high temperature nitriding was able to significantly improve the yield stress, but collapse failure eventually occurred.

  20. Production of titanium alloys for advanced aerospace systems by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Vinicius André Rodrigues Henriques

    2005-12-01

    Full Text Available Titanium alloys parts are ideally suited for advanced aerospace systems because of their unique combination of high specific strength at both room temperature and moderately elevated temperature, in addition to excellent corrosion resistance. Despite these features, use of titanium alloys in engines and airframes is limited by cost. The alloys processing by powder metallurgy eases the obtainment of parts with complex geometry. In this work, results of the Ti-6Al-4V and Ti-13Nb-13Zr alloys production are presented. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900 up to 1500 °C, in vacuum. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. It was shown that the samples were sintered to high densities and presented homogeneous microstructure from the elements dissolution with low interstitial pick-up.

  1. Feasibility study of the production of biomedical Ti-6Al-4V alloy by powder metallurgy.

    Science.gov (United States)

    Bolzoni, L; Ruiz-Navas, E M; Gordo, E

    2015-04-01

    Titanium and its alloys are characterized by an exceptional combination of properties like high strength, good corrosion resistance and biocompatibility which makes them suitable materials for biomedical prosthesis and devices. The wrought Ti-6Al-4V alloy is generally favored in comparison to other metallic biomaterials due to its relatively low elastic modulus and it has been long used to obtain products for biomedical applications. In this work an alternative route to fabricate biomedical implants made out of the Ti-6Al-4V alloy is investigated. Specifically, the feasibility of the conventional powder metallurgy route of cold uniaxial pressing and sintering is addressed by considering two types of powders (i.e. blended elemental and prealloyed). The characterization of physical properties, chemical analysis, mechanical behavior and microstructural analysis is carried out in-depth and the properties are correlated among them. On the base of the results found, the produced alloys are promising materials for biomedical applications as well as cheaper surgical devices and tools. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Titanium nitride deposition in titanium implant alloys produced by powder metallurgy

    International Nuclear Information System (INIS)

    Henriques, V.A.R.; Cairo, C.A.A.; Faria, J.; Lemos, T.G.; Galvani, E.T.

    2009-01-01

    Titanium nitride (TiN) is an extremely hard material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve wear resistance. Electron Beam Physical Vapor Deposition (EB-PVD) is a form of deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum, producing a thin film in a substrate. In this work are presented results of TiN deposition in targets and substrates of Ti (C.P.) and Ti- 13 Nb- 13 Zr obtained by powder metallurgy. Samples were produced by mixing of hydride metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900°C up to 1400 °C, in vacuum. The deposition was carried out under nitrogen atmosphere. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. It was shown that the samples were sintered to high densities and presented homogeneous microstructure, with ideal characteristics for an adequate deposition and adherence. The film layer presented a continuous structure with 15μm. (author)

  3. Compressibility of 304 Stainless Steel Powder Metallurgy Materials Reinforced with 304 Short Stainless Steel Fibers.

    Science.gov (United States)

    Yao, Bibo; Zhou, Zhaoyao; Duan, Liuyang; Xiao, Zhiyu

    2016-03-04

    Powder metallurgy (P/M) technique is usually used for manufacturing porous metal materials. However, some P/M materials are limitedly used in engineering for their performance deficiency. A novel 304 stainless steel P/M material was produced by a solid-state sintering of 304 stainless steel powders and 304 short stainless steel fibers, which were alternately laid in layers according to mass ratio. In this paper, the compressive properties of the P/M materials were characterized by a series of uniaxial compression tests. The effects of fiber content, compaction pressure and high temperature nitriding on compressive properties were investigated. The results indicated that, without nitriding, the samples changed from cuboid to cydariform without damage in the process of compression. The compressive stress was enhanced with increasing fiber content ranging from 0 to 8 wt.%. For compaction pressure from 55 to 75 MPa, greater compaction pressure improved compressive stress. Moreover, high temperature nitriding was able to significantly improve the yield stress, but collapse failure eventually occurred.

  4. Evaluation of the mechanical properties of powder metallurgy Ti-6Al-7Nb alloy.

    Science.gov (United States)

    Bolzoni, L; Ruiz-Navas, E M; Gordo, E

    2017-03-01

    Titanium and its alloys are common biomedical materials owing to their combination of mechanical properties, corrosion resistance and biocompatibility. Powder metallurgy (PM) techniques can be used to fabricate biomaterials with tailored properties because changing the processing parameters, such as the sintering temperature, products with different level of porosity and mechanical performances can be obtained. This study addresses the production of the biomedical Ti-6Al-7Nb alloy by means of the master alloy addition variant of the PM blending elemental approach. The sintering parameters investigated guarantee that the complete diffusion of the alloying elements and the homogenization of the microstructure is achieved. The sintering of the Ti-6Al-7Nb alloy induces a total shrinkage between 7.4% and 10.7% and the level of porosity decreases from 6.2% to 4.7% with the increment of the sintering temperature. Vickers hardness (280-300 HV30) and tensile properties (different combination of strength and elongation around 900MPa and 3%) are achieved. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Characterization of TiC-FeCrMn Cermets Produced by Powder Metallurgy Method

    Directory of Open Access Journals (Sweden)

    Märt Kolnes

    2015-09-01

    Full Text Available TiC-NiMo cermets combine relatively low density with high hardness. Because nickel is known as a toxin and allergen and allergy to nickel is a phenomenon which has assumed growing importance in recent years there has been a flurry of activity to find alternatives to the nickel binder in cermets. It is also the global research and technical development trend in the powder metallurgy cermets industry. In present research TiC-based cermets with FeCrMn binder system were fabricated. Three different sintering conditions were used (vacuum sintering, sinter/HIP and sintering under low Ar pressure. Because of high vapor pressure of manganese different sintering conditions and technologies were investigated to depress the Mn-loss during sintering. Chemical composition of TiC-FeCrMn cermets after different sintering conditions were analyzed by energy-dispersive X-ray spectroscopy (EDS and mechanical properties – hardness and fracture toughness were evaluated on the samples. Results of research showed that Ni-free TiC-based CrMn-steels bonded cermets compare unfavorably with cermets bonded with CrNi austenitic steels in terms of fracture toughness and corrosion resistance. Noticeable Mn-loss during vacuum sintering can be avoided when sintering under low Ar gas pressure.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7364

  6. Deformation and energy absorption properties of powder-metallurgy produced Al foams

    International Nuclear Information System (INIS)

    Michailidis, N.; Stergioudi, F.; Tsouknidas, A.

    2011-01-01

    Highlights: → Porous Al fabricated via a dissolution and sintering method using raw cane sugar. → Different deformation mode depending on the relative density of the foams. → Enhanced energy absorption by reducing pore size and relative density of the foam. → Pore size uniformity and sintering temperature affect energy absorption. - Abstract: Al-foams with relative densities ranging from 0.30 to 0.60 and mean pore sizes of 0.35, 0.70 and 1.35 mm were manufactured by a powder metallurgy technology, based on raw cane sugar as a space-holder material. Compressive tests were carried out to investigate the deformation and energy absorbing characteristics and mechanisms of the produced Al-foams. The deformation mode of low density Al-foams is dominated by the bending and buckling of cell walls and the formation of macroscopic deformation bands whereas that of high density Al-foams is predominantly attributed to plastic yielding. The energy absorbing capacity of Al-foams rises for increased relative density and compressive strength. The sintering temperature of Al-foams having similar relative densities has a marked influence on both, energy absorbing efficiency and capacity. Pore size has a marginal effect on energy efficiency aside from Al-foams with mean pore size of 0.35 which exhibit enhanced energy absorption as a result of increased friction during deformation at lower strain levels.

  7. Microstructurally sensitive crack nucleation around inclusions in powder metallurgy nickel-based superalloys

    International Nuclear Information System (INIS)

    Jiang, J.; Yang, J.; Zhang, T.; Zou, J.; Wang, Y.; Dunne, F.P.E.; Britton, T.B.

    2016-01-01

    Nickel-based superalloys are used in high strength, high-value applications, such as gas turbine discs in aero engines. In these applications the integrity of the disc is critical and therefore understanding crack initiation mechanisms is of high importance. With an increasing trend towards powder metallurgy routes for discs, sometimes unwanted non-metallic inclusions are introduced during manufacture. These inclusions vary in size from ∼10 μm to 200 μm which is comparable to the grain size of the nickel-based superalloys. Cracks often initiate near these inclusions, and the precise size, shape, location and path of these cracks are microstructurally sensitive. In this study, we focus on crack initiation at the microstructural length scale using a controlled three-point bend test, with the inclusion deliberately located within the tensile fibre of the beam. Electron backscatter diffraction (EBSD) is combined with high spatial resolution digital image correlation (HR-DIC) to explore full field plastic strain distributions, together with finite element modelling, to understand the micro-crack nucleation mechanisms. This full field information and controlled sample geometry enable us to systematically test crack nucleation criteria. We find that a combined stored energy and dislocation density provide promising results. These findings potentially facilitate more reliable and accurate lifing prediction tools to be developed and applied to engineering components. - Highlights: • High resolution digital image correlation. • High resolution electron backscatter diffraction. • Crack nucleation. • Non-metallic inclusion.

  8. Power-law creep of powder-metallurgy grade molybdenum sheet

    International Nuclear Information System (INIS)

    Ciulik, J.; Taleff, E.M.

    2007-01-01

    Creep behavior of commercial-purity, powder-metallurgy grade molybdenum (Mo) sheet has been investigated at temperatures between 1300 and 1600 deg. C (0.56-0.63 T m ) using tensile testing at controlled strain rates. Strain-rate-change tests were performed at constant-temperatures over true-strain rates from 1.0 x 10 -6 to 5.0 x 10 -4 s -1 . Results agree with previously published data indicating that Mo follows power-law creep with a stress exponent of about 5; however, the present results address a temperature range not previously documented. The activation energy for creep was determined to be 240 kJ/mol within this temperature range, which is lower than previously published values and approximately half the value reported for self-diffusion, indicating that diffusion mechanisms faster than lattice diffusion are active. It is shown that Mo creep data from a variety of investigations converge closely to a single line on a master plot of strain rate normalized using an activation energy of 240 kJ/mol when plotted against stress normalized by the temperature-dependent elastic modulus. This activation energy for creep is attributed to an effective diffusivity that fits the creep data obtained during this study as well as from previously published creep data from commercial-purity molybdenum

  9. The substitution of nickel for cobalt in hot isostatically pressed powder metallurgy UDIMET 700 alloys

    Science.gov (United States)

    Harf, F. H.

    1985-01-01

    Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine disks. The resultant microstructures displayed three distinct sizes of gamma-prime particles in a gamma matrix. The higher cobalt-content alloys contained larger amounts of the finest gamma-prime particles, and had the lowest gamma-gamma-prime lattice mismatch. While all alloys had approximately the same tensile properties at 25 and 650 gamma C, the rupture lives at 650 and 760 C peaked in the alloys with cobalt contents between 12.7 and 4.3 pct. Minimum creep rates increased as cobalt contents were lowered, suggesting their correlation with the gamma-prime particle size distribution and the gamma-gamma-prime mismatch. It was also found that, on overaging at temperatures higher than suitable for turbine disk use, the high cobalt-content alloys were prone to sigma phase formation.

  10. Factors Influencing Dwell Fatigue Cracking in Notches of Powder Metallurgy Superalloys

    Science.gov (United States)

    Gabb, T. P.; Telesman, J.; Ghosn, L.; Garg, A.; Gayda, J.

    2011-01-01

    The influences of heat treatment and cyclic dwells on the notch fatigue resistance of powder metallurgy disk superalloys were investigated for low solvus high refractory (LSHR) and ME3 disk alloys. Disks were processed to produce material conditions with varied microstructures and associated mechanical properties. Notched specimens were first subjected to baseline dwell fatigue cycles having a dwell at maximum load, as well as tensile, stress relaxation, creep rupture, and dwell fatigue crack growth tests at 704 C. Several material heat treatments displayed a bimodal distribution of fatigue life with the lives varying by two orders-of-magnitude, while others had more consistent fatigue lives. This response was compared to other mechanical properties, in search of correlations. The wide scatter in baseline dwell fatigue life was observed only for material conditions resistant to stress relaxation. For selected materials and conditions, additional tests were then performed with the dwells shifted in part or in total to minimum tensile load. The tests performed with dwells at minimum load exhibited lower fatigue lives than max dwell tests, and also exhibited early crack initiation and a substantial increase in the number of initiation sites. These results could be explained in part by modeling evolution of peak stresses in the notch with continued dwell fatigue cycling. Fatigue-environment interactions were determined to limit life for the fatigue cycles with dwells.

  11. Study on titanium-magnesium composites with bicontinuous structure fabricated by powder metallurgy and ultrasonic infiltration.

    Science.gov (United States)

    Jiang, S; Huang, L J; An, Q; Geng, L; Wang, X J; Wang, S

    2018-02-14

    Titanium-magnesium (Ti-Mg) composites with bicontinuous structure have been successfully fabricated by powder metallurgy and ultrasonic infiltration for biomaterial potential. In the composites, Ti phase is distributed continuously by sintering necks, while Mg phase is also continuous, distributing at the interconnected pores surrounding the Ti phase. The results showed that the fabricated Ti-Mg composites exhibited low modulus and high strength, which are very suitable for load bearing biomedical materials. The composites with 100 µm and 230 µm particle sizes exhibited Young's modulus of 37.6 GPa and 23.4 GPa, 500.7 MPa and 340 MPa of compressive strength and 631.5 MPa and 375.2 MPa of bending strength, respectively. Moreover, both of the modulus and strength of the composites increase with decreasing of Ti particle sizes. In vitro study has been done for the preliminary evaluation of the Ti-Mg composites. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Residual Stresses in a NiCrY-Coated Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Gabb, Timothy P.; Rogers, Richard B.; Nesbitt, James A.; Puleo, Bernadette J.; Miller, Robert A.; Telesman, Ignacy; Draper, Susan L.; Locci, Ivan E.

    2017-01-01

    Protective ductile coatings will be necessary to mitigate oxidation and corrosion attack on superalloy disks exposed to increasing operating temperatures in some turbine engine environments. However, such coatings must be resistant to harmful surface cracking during service. The objective of this study was to investigate how residual stresses evolve in such coatings. Cylindrical gage fatigue specimens of powder metallurgy-processed disk superalloy LSHR were coated with a NiCrY coating, shot peened, and then subjected to fatigue in air at room and high temperatures. The effects of shot peening and fatigue cycling on average residual stresses and other aspects of the coating were assessed. Shot peening did induce beneficial compressive residual stresses in the coating and substrate. However, these stresses became more tensile in the coating with subsequent heating and contributed to cracking of the coating in long intervals of cycling at 760 C. Substantial compressive residual stresses remained in the substrate adjacent to the coating, sufficient to suppress fatigue cracking. The coating continued to protect the substrate from hot corrosion pitting, even after fatigue cracks initiated in the coating.

  13. Dwell Notch Low Cycle Fatigue Behavior of a Powder Metallurgy Nickel Disk Alloy

    Science.gov (United States)

    Telesman, J.; Gabb, T. P.; Yamada, Y.; Ghosn, L. J.; Jayaraman, N.

    2012-01-01

    A study was conducted to determine the processes which govern dwell notch low cycle fatigue (NLCF) behavior of a powder metallurgy (P/M) ME3 disk superalloy. The emphasis was placed on the environmentally driven mechanisms which may embrittle the highly stressed notch surface regions and reduce NLCF life. In conjunction with the environmentally driven notch surface degradation processes, the visco-plastic driven mechanisms which can significantly change the notch root stresses were also considered. Dwell notch low cycle fatigue testing was performed in air and vacuum on a ME3 P/M disk alloy specimens heat treated using either a fast or a slow cooling rate from the solutioning treatment. It was shown that dwells at the minimum stress typically produced a greater life debit than the dwells applied at the maximum stress, especially for the slow cooled heat treatment. Two different environmentally driven failure mechanisms were identified as the root cause of early crack initiation in the min dwell tests. Both of these failure mechanisms produced mostly a transgranular crack initiation failure mode and yet still resulted in low NLCF fatigue lives. The lack of stress relaxation during the min dwell tests produced higher notch root stresses which caused early crack initiation and premature failure when combined with the environmentally driven surface degradation mechanisms. The importance of environmental degradation mechanisms was further highlighted by vacuum dwell NLCF tests which resulted in considerably longer NLCF lives, especially for the min dwell tests.

  14. In vitro degradation and cytotoxicity of Mg/Ca composites produced by powder metallurgy.

    Science.gov (United States)

    Zheng, Y F; Gu, X N; Xi, Y L; Chai, D L

    2010-05-01

    Mg/Ca (1 wt.%, 5 wt.%, 10 wt.% Ca) composites were prepared from pure magnesium and calcium powders using the powder metallurgy method, aiming to enlarge the addition of Ca content without the formation of Mg(2)Ca. The microstructures, mechanical properties and cytotoxicities of Mg/Ca composite samples were investigated. The corrosion of Mg/Ca composites in Dulbecco's modified Eagle's medium (DMEM) for various immersion intervals was studied by electrochemical impedance spectroscopy measurements and environmental scanning electron microscope, with the concentrations of released Mg and Ca ions in DMEM for various immersion time intervals being measured. It was shown that the main constitutional phases were Mg and Ca, which were uniformly distributed in the Mg matrix. The ultimate tensile strength (UTS) and elongation of experimental composites decreased with increasing Ca content, and the UTS of Mg/1Ca composite was comparable with that of as-extruded Mg-1Ca alloy. The corrosion potential increased with increasing Ca content, whereas the current density and the impedance decreased. It was found that the protective surface film formed quickly at the initial immersion stage. With increasing immersion time, the surface film became compact, and the corrosion rate of Mg/Ca composites slowed down. The surface film consisted mainly of CaCO(3), MgCO(3)x3H(2)O, HA and Mg(OH)(2) after 72 h immersion in DMEM. Mg/1Ca and Mg/5Ca composite extracts had no significant toxicity (p>0.05) to L-929 cells, whereas Mg/10Ca composite extract induced approximately 40% reduced cell viability. Copyright (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Effects of carbon and hafnium concentrations in wrought powder-metallurgy superalloys based on NASA 2B-11 alloy

    Science.gov (United States)

    Miner, R. V., Jr.

    1976-01-01

    A candidate alloy for advanced-temperature turbine engine disks, and four modifications of that alloy with various C and Hf concentrations were produced as cross-rolled disks from prealloyed powder that was hot isostatically compacted. The mechanical properties, microstructures, and phase relations of the alloys are discussed in terms of their C and Hf concentrations. A low-C and high-Hf modification of IIB-11 had the best balance of mechanical properties for service below about 750 C. Because of their finer grain sizes, none of the powder-metallurgy alloys produced had the high-temperature rupture strength of conventionally cast and wrought IIB-11.

  16. Powder Metallurgy of Uranium Alloy Fuels for TRU-Burning Reactors Final Technical Report

    International Nuclear Information System (INIS)

    McDeavitt, Sean M.

    2011-01-01

    Overview Fast reactors were evaluated to enable the transmutation of transuranic isotopes generated by nuclear energy systems. The motivation for this was that TRU isotopes have high radiotoxicity and relatively long half-lives, making them unattractive for disposal in a long-term geologic repository. Fast reactors provide an efficient means to utilize the energy content of the TRUs while destroying them. An enabling technology that requires research and development is the fabrication metallic fuel containing TRU isotopes using powder metallurgy methods. This project focused upon developing a powder metallurgical fabrication method to produce U-Zr-transuranic (TRU) alloys at relatively low processing temperatures (500 C to 600 C) using either hot extrusion or alpha-phase sintering for charecterization. Researchers quantified the fundamental aspects of both processing methods using surrogate metals to simulate the TRU elements. The process produced novel solutions to some of the issues relating to metallic fuels, such as fuel-cladding chemical interactions, fuel swelling, volatility losses during casting, and casting mold material losses. Workscope There were two primary tasks associated with this project: (1) Hot working fabrication using mechanical alloying and extrusion - Design, fabricate, and assemble extrusion equipment - Extrusion database on DU metal - Extrusion database on U-10Zr alloys - Extrusion database on U-20xx-10Zr alloys - Evaluation and testing of tube sheath metals (2) Low-temperature sintering of U alloys - Design, fabricate, and assemble equipment - Sintering database on DU metal - Sintering database on U-10Zr alloys - Liquid assisted phase sintering on U-20xx-10Zr alloys Appendices Outline Appendix A contains a Fuel Cycle Research and Development (FCR and D) poster and contact presentation where TAMU made primary contributions. Appendix B contains MSNE theses and final defense presentations by David Garnetti and Grant Helmreich outlining the

  17. Powder Metallurgy of Uranium Alloy Fuels for TRU-Burning Reactors Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean M

    2011-04-29

    Overview Fast reactors were evaluated to enable the transmutation of transuranic isotopes generated by nuclear energy systems. The motivation for this was that TRU isotopes have high radiotoxicity and relatively long half-lives, making them unattractive for disposal in a long-term geologic repository. Fast reactors provide an efficient means to utilize the energy content of the TRUs while destroying them. An enabling technology that requires research and development is the fabrication metallic fuel containing TRU isotopes using powder metallurgy methods. This project focused upon developing a powder metallurgical fabrication method to produce U-Zr-transuranic (TRU) alloys at relatively low processing temperatures (500ºC to 600ºC) using either hot extrusion or alpha-phase sintering for charecterization. Researchers quantified the fundamental aspects of both processing methods using surrogate metals to simulate the TRU elements. The process produced novel solutions to some of the issues relating to metallic fuels, such as fuel-cladding chemical interactions, fuel swelling, volatility losses during casting, and casting mold material losses. Workscope There were two primary tasks associated with this project: 1. Hot working fabrication using mechanical alloying and extrusion • Design, fabricate, and assemble extrusion equipment • Extrusion database on DU metal • Extrusion database on U-10Zr alloys • Extrusion database on U-20xx-10Zr alloys • Evaluation and testing of tube sheath metals 2. Low-temperature sintering of U alloys • Design, fabricate, and assemble equipment • Sintering database on DU metal • Sintering database on U-10Zr alloys • Liquid assisted phase sintering on U-20xx-10Zr alloys Appendices Outline Appendix A contains a Fuel Cycle Research & Development (FCR&D) poster and contact presentation where TAMU made primary contributions. Appendix B contains MSNE theses and final defense presentations by David Garnetti and Grant Helmreich

  18. Obtainment, machining and wear of metal matrix composites processed by powder metallurgy

    International Nuclear Information System (INIS)

    Jesus, Edilson Rosa Barbosa de.

    1998-01-01

    The aim of this investigation was the obtainment of metal matrix composites (MMC) by the route of powder metallurgy, and the valuation of these materials with relation to their machining and wear characteristics. Firstly, were obtained pure commercial aluminium matrix composites materials, with 5, 10 and 15% volumetric fraction of silicon carbide particles. Was also obtained a material without reinforcement particles in order to verify by comparison, the influence of addition of reinforcement particles. The obtained materials were characterized physics (hydrostatic density), mechanics (hardness and tensile tests) and microstructurally (optical microscopy and scanning electron microscopy). The results showed a homogeneous distribution of reinforcement particles in the composite, and improvement in the mechanical properties, mainly tensile strength (UTS) in comparison to the unreinforced material. After, tests were made to verify the materials behavior during machining and to check the performance of several tool materials (cemented carbide, ceramics and polycrystalline diamond). In these tests, values of the cutting force were measured by instrumented tool-holders. Phenomena such as tool wear, built-up edge formation and mechanism of chip formation were also observed and evaluated. The results from the cemented carbide tool tests, were utilised for the machinability index determination of each material. These results were applied to the Taylor equation and the equation constants for each material and test conditions were determined. The results showed that the inclusion of silicon carbide particles made extremely difficult the machining of the composites, and only with diamond tool, satisfactory results were obtained. At last, wear tests were performed to verify the influence of the reinforcement particles in the characteristics of wear resistance of the materials. The results obtained were utilized in the wear coefficient determination for each material. The

  19. Filamentary niobium--tin superconductors fabricated by a powder metallurgy approach

    International Nuclear Information System (INIS)

    Hemachalam, K.

    1976-02-01

    Procedures are described for making superconducting tapes and wires containing filments of the A-15 compound, Nb 3 Sn, by powder metallurgy techniques. The Nb 3 Sn filaments, typically 1-5 m thick, are formed by a short heat treatment. The effects of process variables on the microstructure of the tapes and wires were investigated. Microstructural aspects were examined by optical metallography and transmission electron microscopy. A pulsed field technique was used to determine the critical current density, J/sub c/, at 4.2 0 K as a function of transverse magnetic field up to 170 kG. Satisfactory agreement was oserved between these results and data obtained under steady fields of up to 100 kG. The J/sub c/ of the conductors are related to their individual filament morphologies resulting from the different thermo-mechanical histories. The effect of heat treatment conditions on critical current and transition temperature, T/sub c/, is presented. Through process modifications, optimal values or ranges are developed for the metallugical variables in order to maximize the superconducting properties. The inductively measured T/sub c/ of the conductors is about 17.9 +- 0.1 0 . The values of J/sub c/ for the wires computed on the basis of Nb 3 Sn and niobium matrix are 2.3 x 10 5 A/cm 2 at a transverse pulse field of 50 kG, 1.1 x 10 5 A/cm 2 at 100 kG and 7.5 x 10 4 A/cm 2 at 150 kG

  20. Application of Microscopy and X-ray Diffraction in Optimization of the Production of NiTi Alloy by Powder Metallurgy

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Školáková, A.; Vojtěch, V.; Knaislová, A.; Pokorný, P.; Moravec, H.; Kopeček, Jaromír; Karlík, M.; Kubatík, Tomáš František

    2014-01-01

    Roč. 14, č. 3 (2014), s. 387-392 ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : powder metallurgy * NiTi, * mechanical alloying * reactive sintering Subject RIV: JG - Metallurgy; JG - Metallurgy (FZU-D) http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

  1. Study of alumina-trichite reinforcement of a nickel-based matric by means of powder metallurgy

    Science.gov (United States)

    Walder, A.; Hivert, A.

    1982-01-01

    Research was conducted on reinforcing nickel based matrices with alumina trichites by using powder metallurgy. Alumina trichites previously coated with nickel are magnetically aligned. The felt obtained is then sintered under a light pressure at a temperature just below the melting point of nickel. The halogenated atmosphere technique makes it possible to incorporate a large number of additive elements such as chromium, titanium, zirconium, tantalum, niobium, aluminum, etc. It does not appear that going from laboratory scale to a semi-industrial scale in production would create any major problems.

  2. Effect of sintering conditions on the microstructural and mechanical characteristics of porous magnesium materials prepared by powder metallurgy.

    Science.gov (United States)

    Čapek, Jaroslav; Vojtěch, Dalibor

    2014-02-01

    There has recently been an increased demand for porous magnesium materials in many applications, especially in the medical field. Powder metallurgy appears to be a promising approach for the preparation of such materials. Many works have dealt with the preparation of porous magnesium; however, the effect of sintering conditions on material properties has rarely been investigated. In this work, we investigated porous magnesium samples that were prepared by powder metallurgy using ammonium bicarbonate spacer particles. The effects of the purity of the argon atmosphere and sintering time on the microstructure (SEM, EDX and XRD) and mechanical behaviour (universal loading machine and Vickers hardness tester) of porous magnesium were studied. The porosities of the prepared samples ranged from 24 to 29 vol.% depending on the sintering conditions. The purity of atmosphere played a significant role when the sintering time exceeded 6h. Under a gettered argon atmosphere, a prolonged sintering time enhanced diffusion connections between magnesium particles and improved the mechanical properties of the samples, whereas under a technical argon atmosphere, oxidation at the particle surfaces caused deterioration in the mechanical properties of the samples. These results suggest that a refined atmosphere is required to improve the mechanical properties of porous magnesium. © 2013.

  3. Powder metallurgy preparation of Al-Cu-Fe quasicrystals using mechanical alloying and Spark Plasma Sintering

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Kubatík, Tomáš František; Vystrčil, J.; Hendrych, R.; Kříž, J.; Mlynár, J.; Vojtěch, D.

    2014-01-01

    Roč. 52, September (2014), s. 131-137 ISSN 0966-9795 Institutional support: RVO:61389021 Keywords : Nanostructure intermetallics * Ternary alloys systems * Mechanical alloying and milling * Sintering * Diffraction Subject RIV: JG - Metallurgy Impact factor: 2.131, year: 2014 http://www.sciencedirect.com/science/article/pii/S0966979514001198#

  4. Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

    Science.gov (United States)

    Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

    2016-01-01

    Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240–260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180–210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time. PMID:26837848

  5. Effects of Thermocapillary Forces during Welding of 316L-Type Wrought, Cast and Powder Metallurgy Austenitic Stainless Steels

    CERN Document Server

    Sgobba, Stefano

    2003-01-01

    The Large Hadron Collider (LHC) is now under construction at the European Organization for Nuclear Research (CERN). This 27 km long accelerator requires 1248 superconducting dipole magnets operating at 1.9 K. The cold mass of the dipole magnets is closed by a shrinking cylinder with two longitudinal welds and two end covers at both extremities of the cylinder. The end covers, for which fabrication by welding, casting or Powder Metallurgy (PM) was considered, are dished-heads equipped with a number of protruding nozzles for the passage of the different cryogenic lines. Structural materials and welds must retain high strength and toughness at cryogenic temperature. AISI 316L-type austenitic stainless steel grades have been selected because of their mechanical properties, ductility, weldability and stability of the austenitic phase against low-temperature spontaneous martensitic transformation. 316LN is chosen for the fabrication of the end covers, while the interconnection components to be welded on the protrud...

  6. Effects of Temperature and Pressure of Hot Isostatic Pressing on the Grain Structure of Powder Metallurgy Superalloy.

    Science.gov (United States)

    Tan, Liming; He, Guoai; Liu, Feng; Li, Yunping; Jiang, Liang

    2018-02-24

    The microstructure with homogeneously distributed grains and less prior particle boundary (PPB) precipitates is always desired for powder metallurgy superalloys after hot isostatic pressing (HIPping). In this work, we studied the effects of HIPping parameters, temperature and pressure on the grain structure in PM superalloy FGH96, by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), transmission electron microscope (TEM) and Time-of-flight secondary ion spectrometry (ToF-SIMS). It was found that temperature and pressure played different roles in controlling PPB precipitation and grain structure during HIPping, the tendency of grain coarsening under high temperature could be inhibited by increasing HIPping pressure which facilitates the recrystallization. In general, relatively high temperature and pressure of HIPping were preferred to obtain an as-HIPped superalloy FGH96 with diminished PPB precipitation and homogeneously refined grains.

  7. Advanced Mechanical Properties of a Powder Metallurgy Ti-Al-N Alloy Doped with Ultrahigh Nitrogen Concentration

    Science.gov (United States)

    Shen, J.; Chen, B.; Umeda, J.; Kondoh, K.

    2018-03-01

    Titanium and its alloys are recognized for their attractive properties. However, high-performance Ti alloys are often alloyed with rare or noble-metal elements. In the present study, Ti alloys doped with only ubiquitous elements were produced via powder metallurgy. The experimental results showed that pure Ti with 1.5 wt.% AlN incorporated exhibited excellent tensile properties, superior to similarly extruded Ti-6Al-4V. Further analysis revealed that its remarkably advanced strength could primarily be attributed to nitrogen solid-solution strengthening, accounting for nearly 80% of the strength increase of the material. In addition, despite the ultrahigh nitrogen concentration up to 0.809 wt.%, the Ti-1.5AlN sample showed elongation to failure of 10%. This result exceeds the well-known limitation for nitrogen (over 0.45 wt.%) that causes embrittlement of Ti alloys.

  8. Phase evolution, mechanical and corrosion behavior of Fe(100-x) Ni(x) alloys synthesized by powder metallurgy

    Science.gov (United States)

    Singh, Neera; Parkash, Om; Kumar, Devendra

    2018-03-01

    In the present investigation, Fe(100-x) Ni(x) alloys (x = 10, 20, 30, 40 and 50 wt%) were synthesized through the evolution of γ-taenite and α-kamacite phases by powder metallurgy route using commercially available Fe and Ni powders. Mechanically mixed powders of Fe and Ni were compacted at room temperature and sintered at three different temperatures 1000, 1200 and 1250 °C for 1 h. Both Ni concentration and sintering temperature have shown a strong impact on the phase formation, tribological and electrochemical behavior. Micro structural study has shown the formation of taenite (γ-Fe,Ni) and kamacite (α-Fe,Ni) phases in the sintered specimens. An increase in Ni fraction resulted in formation of more taenite which reduces hardness and wear resistance of specimens. Increasing the sintering temperature decreased the defect concentration with enhanced taenite formation, aiding to higher densification. Taenite formed completely in Fe50Ni50 after sintering at 1250 °C. Tribological test revealed the maximum wear resistance for Fe70Ni30 specimen due to the presence of both kamacite and taenite in significant proportions. The formation of taenite as well as the decrease in defect concentration improves the corrosion resistance of the specimens significantly in 1M HCl solution. A maximum corrosion protection efficiency of around ∼87% was achieved in acidic medium for Fe50Ni50, sintered at 1250 °C.

  9. Effect of intercritical annealing and quenching plus tempering heat treatments on microstructure of Ni added powder metallurgy steels

    International Nuclear Information System (INIS)

    Tekeli, S.; Gueral, A.

    2007-01-01

    In this study, intercritical annealing, which is usually practiced to low alloy ingot steels, and quenching + tempering heat treatments were applied to low alloy powder metallurgy steel. For these purposes, atomized iron powder (Ancorsteel 1000) was mixed with 0.3% graphite and Ni ranging 0-2% (wt.). The mixed powders were cold pressed at 700 MPa and sintered at 1200 deg. C for 30 min under pure Ar gas atmosphere. Some of the sintered specimens was quenched from 890 deg. C and tempered at 200 and 400 deg. C for 1 h. The other sintered specimens were annealed at intercritical heat treatment temperatures of 728 and 760 deg. C and quenched in water. The experimental results showed that a typical tempered martensite microstructure was obtained in the specimen without Ni addition after quenching + tempering, whereas the dispersion of Ni-rich areas in the microstructure of tempered martensite in Ni-added specimens was seen. With increasing tempering temperature, the volume fraction of Ni-rich areas slightly decreased. While ferrite + martensite microstructure was produced after intercritical annealing heat treatment, Ni-rich areas in the centre of martensite islands in ferrite matrix were seen in Ni-added specimens. Also, with increasing intercritical annealing temperature and Ni content, martensite volume fraction increased and ferrite ratio decreased

  10. The wear properties of in-situ 7075 Al-Ti composites produced by powder metallurgy route

    Energy Technology Data Exchange (ETDEWEB)

    Ay, H.; Özyurek, D.; Yıldırım, M., E-mail: musayildirim@karabuk.edu.tr [Karabük University, Technology Faculty, Department of Manufacturing Engineering / Karabuk (Turkey); Bostan, B. [Gazi University, Technology Faculty, Department of Metallurgy and Materials Engineering (Turkey)

    2016-04-21

    In this study, the wear properties of in-situ 7075 Al-Ti composites produced by powder metallurgy route were investigated. Different amount of Ti (2, 4, 6 %) added to gas atomized 7075 Al alloy powders and they were mixed in turbula with 47rpm for 45 minutes. Then the mixed powders were pre-shaped by press under 600 MPa pressure. The samples were cooled in the furnace after sintered at 580 °C for 4 hours in the atmosphere controlled furnace. Standard metallographic process such as grinding, polishing and etching were applied to sintered samples. The hardness values were measured. Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) examines were carried out. The wear tests were performed in a pin-on disc type wear apparatus with 1 ms{sup −1} sliding speed at six different sliding distance (500-3000 m) under 30 N loads. As a result of studies, hardness values were increased with increasing Ti content, in addition the weight losses were decreased with increasing Ti amount.

  11. Histomorphologic evaluation of Ti-13Nb-13Zr alloys processed via powder metallurgy. A study in rabbits

    International Nuclear Information System (INIS)

    Bottino, M.C.; Coelho, P.G.; Yoshimoto, M.; Koenig, B.; Henriques, V.A.R.; Bressiani, A.H.A.; Bressiani, J.C.

    2008-01-01

    This study presents the in-vivo evaluation of Ti-13Nb-13Zr alloy implants obtained by the hydride route via powder metallurgy. The cylindrical implants were processed at different sintering and holding times. The implants' were characterized for density, microstructure (SEM), crystalline phases (XRD), and bulk (EDS) and surface composition (XPS). The implants were then sterilized and surgically placed in the central region of the rabbit's tibiae. Two double fluorescent markers were applied at 2 and 3 weeks, and 6 and 7 weeks after implantation. After an 8-week healing period, the implants were retrieved, non-decalcified section processed, and evaluated by electron, UV light (fluorescent labeling), and light microscopy (toluidine blue). BSE-SEM showed close contact between bone and implants. Fluorescent labeling assessment showed high bone activity levels at regions close to the implant surface. Toluidine blue staining revealed regions comprising osteoblasts at regions of newly forming/formed bone close to the implant surface. The results obtained in this study support biocompatible and osseoconductive properties of Ti-13Nb-13Zr processed through the hydride powder route

  12. Histomorphologic evaluation of Ti-13Nb-13Zr alloys processed via powder metallurgy. A study in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Bottino, M.C. [Department of Materials Science and Engineering, University of Alabama at Birmingham, BEC 254 1530 3rd Avenue South, Birmingham, AL, 35294 (United States); Coelho, P.G. [Department of Biomaterials and Biomimetics, New York University, College of Dentistry, 345 East 24th Street, Room 804S, New York, NY, 10100 (United States)], E-mail: pgcoelho@nyu.edu; Yoshimoto, M. [Materials Science and Technology Center, Institute for Energy and Nuclear Research, Av. Prof. Lineu Prestes, 2242, Sao Paulo, SP, 05508-000 (Brazil); Koenig, B. [Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo (ICB-USP) Av. Prof. Lineu Prestes, 2415, Sao Paulo, SP, 05508-900 (Brazil); Henriques, V.A.R. [Materials Division (AMR/IAE), CTA Brazilian Aerospace Technical Center, Sao Jose dos Campos, SP, 12228-904 (Brazil); Bressiani, A.H.A.; Bressiani, J.C. [Materials Science and Technology Center, Institute for Energy and Nuclear Research, Av. Prof. Lineu Prestes, 2242, Sao Paulo, SP, 05508-000 (Brazil)

    2008-03-10

    This study presents the in-vivo evaluation of Ti-13Nb-13Zr alloy implants obtained by the hydride route via powder metallurgy. The cylindrical implants were processed at different sintering and holding times. The implants' were characterized for density, microstructure (SEM), crystalline phases (XRD), and bulk (EDS) and surface composition (XPS). The implants were then sterilized and surgically placed in the central region of the rabbit's tibiae. Two double fluorescent markers were applied at 2 and 3 weeks, and 6 and 7 weeks after implantation. After an 8-week healing period, the implants were retrieved, non-decalcified section processed, and evaluated by electron, UV light (fluorescent labeling), and light microscopy (toluidine blue). BSE-SEM showed close contact between bone and implants. Fluorescent labeling assessment showed high bone activity levels at regions close to the implant surface. Toluidine blue staining revealed regions comprising osteoblasts at regions of newly forming/formed bone close to the implant surface. The results obtained in this study support biocompatible and osseoconductive properties of Ti-13Nb-13Zr processed through the hydride powder route.

  13. Effect of high energy milling time of the aluminum bronze alloy obtained by powder metallurgy with niobium carbide addition

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Alexandre Nogueira Ottoboni; Silva, Aline da; Rodrigues, Carlos Alberto; Melo, Mirian de Lourdes Noronha Motta; Rodrigues, Geovani; Silva, Gilbert, E-mail: aottoboni@yahoo.com.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil)

    2017-05-15

    The aluminum bronze alloy is part of a class of highly reliable materials due to high mechanical strength and corrosion resistance being used in the aerospace and shipbuilding industry. It's machined to produce parts and after its use cycle, it's discarded, but third process is considered expensive and besides not being correct for environment reasons. Thus, reusing this material through the powder metallurgy (PM) route is considered advantageous. The aluminum bronze chips were submitted to high energy ball milling process with 3% of niobium carbide (NbC) addition. The NbC is a metal-ceramic composite with a ductile-brittle behaviour. It was analyzed the morphology of powders by scanning electron microscopy as well as particle size it was determined. X ray diffraction identified the phases and the influence of milling time in the diffractogram patterns. Results indicates that milling time and NbC addition improves the milling efficiency significantly and being possible to obtain nanoparticles. (author)

  14. Titanium dental copings prepared by a powder metallurgy method: a preliminary report.

    Science.gov (United States)

    Eriksson, Mikael; Andersson, Matts; Carlström, Elis

    2004-01-01

    The purpose of this study was to determine if the Procera pressed-powder method can be used to fabricate titanium copings. Commercially pure titanium powder was used to prepare the copings. The powder was pressed onto an enlarged tooth preparation die of aluminum using cold isostatic pressing. The outer shape of the coping was formed using a Procera milling machine, and the copings were vacuum sintered. Titanium copings could be prepared using this method. The density of the sintered copings reached 97% to 99%+ of theoretic density, and the copings showed ductile behavior after sintering. Enlarging the tooth preparation die to compensate for the sintering shrinkage could optimize the final size of the copings. Ductile and dense titanium dental copings can be produced with powder-metal processing using cold isostatic pressing, followed by milling and sintering to final shape. The forming technique has, if properly optimized, a potential of becoming a more cost-efficient production method than spark erosion.

  15. Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy

    KAUST Repository

    Vlach, Martin

    2013-12-01

    The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al3Sc and/or Al3(Sc,Zr) particles precipitated during extrusion at 350 C in the alloys studied. Additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 C. The precipitation of the Al6Mn- and/or Al 6(Mn,Fe) particles of a size ~ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al3Sc particles formation and/or coarsening and that of the Al6Mn and/or Al 6(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al3Sc-phase and the Al 6Mn-phase precipitation. © 2013 Elsevier Inc.

  16. Synthesis of niobium carbide (NbC) by powder metallurgy high energy milling technique

    International Nuclear Information System (INIS)

    Antonello, Rodrigo Tecchio; Urtiga Filho, Severino Leopoldino; Araujo Filho, Oscar Olimpio de; Ambrozio Filho, Francisco; Gonzalez, Cezar Henrique

    2009-01-01

    The aim of this work is to obtain and characterize the Niobium Carbide (NbC) by a suitable high energy milling technique using a SPEX Mill vibratory type and niobium and carbon (graphite) powders. Since this carbide is scarce in the national market and it's necessary to apply this NbC as a reinforcement in two molybdenum high speed steels (AISI M2 and AISI M3:2) object of another work motivated this research. The powders were submitted to a high energy milling procedure for suitable times and conditions and then were characterized by means of Scanning Electronic Microscopy (SEM) and X-ray diffraction (DRX) techniques. The ball-to-powder weight ratio was 10:1. The analysed samples showed that the high-energy milling is an alternative route of the NbC synthesis. (author)

  17. Review of some past and present powder metallurgy programs at the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Sheinberg, H.

    1977-07-01

    A new process is described for molding and extruding complicated shapes of uranium-loaded graphite to close tolerances for use in nuclear propulsion engines. The process for hot-pressing copper-boron carbide and forming it into sheet for use as neutronic control material for these engines is also described. Fabrication procedure and deformation testing of carbide-graphite composites for fuel element supports are outlined, as is the procedure for fabricating tungsten-thoria heat shields for these reactors. Details are given for production of uranium carbide-zirconium carbide solid-solution powder and fabrication of this powder and molybdenum uranium oxide powder into fuel pins for thermionic reactors. Methods and details are given for spheroidization of lithium deuteride to be used as laser fusion targets and for quality upgrading and characterization of micron-size balloons for that use

  18. Additively Manufactured, Net Shape Powder Metallurgy Cans for Valves Used in Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Peter, William H. [ORNL; Gandy, David [Electric Power Research Institute (EPRI); Lannom, Robert [Oak Ridge National Laboratory (ORNL)

    2018-01-01

    This CRADA NFE-14-05241 was conducted as a Technical Collaboration project within the Oak Ridge National Laboratory (ORNL) Manufacturing Demonstration Facility (MDF) sponsored by the US Department of Energy Advanced Manufacturing Office (CPS Agreement Number 24761). Opportunities for MDF technical collaborations are listed in the announcement “Manufacturing Demonstration Facility Technology Collaborations for US Manufacturers in Advanced Manufacturing and Materials Technologies” posted at http://web.ornl.gov/sci/manufacturing/docs/FBO-ORNL-MDF-2013-2.pdf. The goal of technical collaborations is to engage industry partners to participate in short-term, collaborative projects within the Manufacturing Demonstration Facility (MDF) to assess applicability and of new energy efficient manufacturing technologies. Research sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.ORNL would like to acknowledge the leadership of EPRI in pulling together the extensive team and managing the execution of the project. In addition, ORNL would like to acknowledge the other contributions of the team members associated with this project. Quintus provided time, access, expertise, and labor of their hydro forming capabilities to evaluate both conventional and additively manufactured tools through this process. Crane ChemPharma Energy provided guidance and information on valve geometries. Carpenter Powder Products was involved with the team providing information on powder processing as it pertains to the canning and hot isostatic pressing of powder. on providing powder and knowledge as it pertains to powder supply for hot isostatic pressing; they also provided powder for the test trials by the industrial team. Bodycote provided guidance on hot isostatic pressing and can requirements. They were also responsible for the hot isostatic pressing of the test valve

  19. Powder metallurgy and mechanical alloying effects on the formation of thermally induced martensite in an FeMnSiCrNi SMA

    Directory of Open Access Journals (Sweden)

    Pricop Bogdan

    2015-01-01

    Full Text Available By ingot metallurgy (IM, melting, alloying and casting, powder metallurgy (PM, using as-blended elemental powders and mechanical alloying (MA of 50 % of particle volume, three types of FeMnSiCrNi shape memory alloy (SMA specimens were fabricated, respectively. After specimen thickness reduction by hot rolling, solution treatments were applied, at 973 and 1273 K, to thermally induce martensite. The resulting specimens were analysed by X-ray diffraction (XRD and scanning electron microscopy (SEM, in order to reveal the presence of ε (hexagonal close-packed, hcp and α’ (body centred cubic, bcc thermally induced martensites. The reversion of thermally induced martensites, to γ (face centred cubic, fcc austenite, during heating, was confirmed by dynamic mechanical analysis (DMA, which emphasized marked increases of storage modulus and obvious internal friction maxima on DMA thermograms. The results proved that the increase of porosity degree, after PM processing, increased internal friction, while MA enhanced crystallinity degree.

  20. Investigation of hydrostatic extrusion and other deformation modes for the fabrication of multifilamentary niobium--tin superconductors by a powder metallurgy approach

    International Nuclear Information System (INIS)

    MacLeod, G.E.

    1977-06-01

    Various aspects of a powder metallurgy approach to fabricate filamentary niobium-tin superconducting wire were investigated. Difficulties occurred due to lack of complete tin infiltration of the sintered niobium rod, formation of intermetallics during infiltration, and both cladding and core fracture during mechanical reduction. The influence of sintering time, infiltration temperature, and deformation mode was investigated. Progress is reported on the clarification of the role of several of the important process parameters

  1. A Model for Converting Dilatometric Strain Measurements to the Fraction of Phase Formed during the Transformation of Austenite to Martensite in Powder Metallurgy Steels

    Science.gov (United States)

    Warke, Virendra S.; Sisson, Richard D.; Makhlouf, Makhlouf M.

    2009-03-01

    A model is developed to allow converting dilatometric strains that occur during the continuous cooling transformation (CCT) of austenite to martensite to volume fraction martensite formed in powder metallurgy steels. Unlike existing models, this model can accurately account for the observed decrease in the measured transformation strain with increased porosity. As a demonstration, the model is used to accurately calculate the volume fraction of martensite formed during the CCT of austenite to martensite in FL-4605 PM steel.

  2. Fe-Mn-Si master alloy steel by powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zongyin; Sandstroem, Rolf

    2004-01-28

    Fe-Mn-Si master alloy powders were produced by three methods: milling, atomising, and a combination of atomisation and milling. The effects of sintering temperature, time and atmosphere on the properties of sintered steels with these Fe-Mn-Si master alloy powders were studied. The density of the compacts increases with sintering temperature and time. The ultimate tensile strength and hardness increases with sintering temperature and time mainly due to increasing amounts of bainite and martensite after cooling. Elongation is initially raised with sintering temperature and time probably due to improved bonding between powder particles. The compacts with the milled and atomised-milled master alloy showed about the same mechanical properties. On the other hand, the steel with the atomised powder gave lower strength and elongation in both hydrogen and argon-5% hydrogen. Small dimensional changes have been obtained in the steels with milled and atomised-milled Fe-Mn-Si master alloys sintered at 1200 deg. C. It was shown that transient liquid phase sintering accelerates the sintering process, which leads to improved mechanical properties.

  3. Microstructure and mechanical properties of a new group of nanocrystalline medical-grade stainless steels prepared by powder metallurgy

    International Nuclear Information System (INIS)

    Javanbakht, M.; Hadianfard, M.J.; Salahinejad, E.

    2015-01-01

    Highlights: • This paper focuses on the structure and mechanical properties of PM alloys. • A eutectic Mn–Si alloy sintering aid was successfully used. • Mechanical properties were improved by adding the sintering aid. - Abstract: This paper focuses on the structure and mechanical properties of powder metallurgy stainless steels (Fe–Cr–Mn–Mo–Si–N–C) developed for biomedical applications. The samples were prepared by mechanical alloying and subsequent liquid-phase sintering with a eutectic Mn–Si alloy additive. By changing the sintering aid content, the pore configuration, compressive strengths, and impact properties of the samples were assessed. The Rietveld X-ray diffraction analysis showed after sintering at 1050 °C for 60 min followed by water-quenching, a nanocrystalline austenitic structure was formed in the material. According to the mechanical experiments, by increasing the additive content from 0 wt% to 6 wt%, sintering densification, yield stress, compression strength, and absorbed impact energy were improved, where spoiling occurred when adding 8 wt% additive. Also, as realized from the impact fracture surface features, despite the presence of some unmelted additive particles, the role of the pore elimination in toughness prevailed over that of these particles

  4. Human alveolar bone cell proliferation, expression of osteoblastic phenotype, and matrix mineralization on porous titanium produced by powder metallurgy.

    Science.gov (United States)

    Rosa, Adalberto Luiz; Crippa, Grasiele Edilaine; de Oliveira, Paulo Tambasco; Taba, Mario; Lefebvre, Louis-Philippe; Beloti, Marcio Mateus

    2009-05-01

    This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour. Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 microm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days. Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers-runt-related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein-7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one. These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three-dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface-bone interactions.

  5. Microstructural analyses of intermetallic TiAl(Nb)-compounds prepared by arc melting and by powder metallurgy

    International Nuclear Information System (INIS)

    Chen, S.

    1988-01-01

    Intermetallic compounds based on TiAl with Nb or V as alloying additions prepared by powder metallurgy (P/M) and arc melting (A/M) techniques have been investigated with respect to their potential as new high temperature materials. All the alloys with nominal Al-concentrations 34-36 wt% contain two phases, γ-TiAl and α 2 -Ti 3 Al, but significant differences in the distribution of γ and α 2 were found between the P/M and A/M materials. The role of impurities during processing and the microstructural stability in the planned service temperature range 700-1000 0 C are discussed. In the P/M TiAl alloys two carbide precipitates have been found, which are the cubic Perovskite-AlTi 3 C phase in the γ-matrix and the hexagonal H-AlTi 2 (C, N) phase at grain boundaries. At high temperatures the AlTi 3 C phase dissolves and is replaced by more stable H-phase, and therefore no longer contributes to the high temperature strength of the material. Mechanical properties of both the P/M and A/M alloys are compared in association with the processing methods and the resulting microstructures. (orig.) With 71 figs., 22 tabs [de

  6. In situ synthesis and strengthening of powder metallurgy high speed steel in addition of LaB6

    Science.gov (United States)

    Shen, Weijun; Yu, Linping; Li, Zhi; He, Yuehui; Zhang, Qiankun; Zhang, Huibin; Jiang, Yao; Lin, Nan

    2017-11-01

    A novel technology which was characterized by the vacuum solid state sintering was developed for powder metallurgy high speed steels production. During sintering, both the WC and Mo2C reacted with Fe and transformed to W and Mo rich M6C carbides which were the common hard phases in high speed steels. Also, a high number of W, Mo and Fe were dissolved in VC, forming the MC carbides. The densification of the material mainly relied on the solubility effect during the M6C and MC carbides formation. By alloying with a 0.1 wt% of LaB6 to the steel, the bending strength and the fracture toughness were improved from 3290 MPa and 25.6 MPam1/2 to 4018 MPa and 29.4 MPam1/2, respectively. The TEM analysis demonstrated three types of reaction products by the LaB6 addition: the amorphous phase, the core-shell structure and the La2O3 phase. The impurity elements such as the Mg, Al, Si, S, Ca, and O were absorbed following the LaB6 addition. Moreover, the deoxidization effect caused by the LaB6 addition promoted the sintering at a high-temperature period which contributed to the bending strength and fracture toughness improvement.

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

    Science.gov (United States)

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

    2011-12-01

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

  8. Effect of reduced cobalt contents on hot isostatically pressed powder metallurgy U-700 alloys

    Science.gov (United States)

    Harf, F. H.

    1982-01-01

    The effect of reducing the cobalt content of prealloyed powders of UDIMET 700 (U-700) alloys to 12.7, 8.6, 4.3, and 0% was examined. The powders were hot isostatically pressed into billets, which were given heat treatments appropriate for turbine disks, namely partial solutioning at temperatures below the gamma prime solvus and four step aging treatments. Chemical analyses, metallographic examinations, and X-ray diffraction measurements were performed on the materials. Minor effects on gamma prime content and on room temperature and 650 C tensile properties were observed. Creep rupture lives at 650 C reached a maximum at the 8.4% concentration, while at 760 C a maximum in life was reached at the 4.3% cobalt level. Minimum creep rates increased with decreasing cobalt content at both test temperatures. Extended exposures at 760 and 815 C resulted in decreased tensile strengths and rupture lives for all alloys. Evidence of sigma phase formation was also found.

  9. Precipitation in cold-rolled Al–Sc–Zr and Al–Mn–Sc–Zr alloys prepared by powder metallurgy

    International Nuclear Information System (INIS)

    Vlach, M.; Stulikova, I.; Smola, B.; Kekule, T.; Kudrnova, H.; Danis, S.; Gemma, R.; Ocenasek, V.; Malek, J.; Tanprayoon, D.; Neubert, V.

    2013-01-01

    The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 °C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al 3 Sc and/or Al 3 (Sc,Zr) particles precipitated during extrusion at 350 °C in the alloys studied. Additional precipitation of the Al 3 Sc and/or Al 3 (Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 °C. The precipitation of the Al 6 Mn- and/or Al 6 (Mn,Fe) particles of a size ∼ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 °C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al 3 Sc particles formation and/or coarsening and that of the Al 6 Mn and/or Al 6 (Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al 3 Sc-phase and the Al 6 Mn-phase precipitation. - Highlights: • The Mn, Sc and Zr additions to Al totally suppresses recrystallization at 550 °C. • The Sc,Zr-containing particle precipitation is slightly facilitated by

  10. A novel approach using powder metallurgy for strengthened RABiTS composite substrates for coated superconductors

    International Nuclear Information System (INIS)

    Suo Hongli; Zhao Yue; Liu Min; Ye Shuai; Zhu YongHua; He Dong; Ma Lingji; Ji Yuan; Zhou Meiling

    2008-01-01

    We report on the development of mechanically strengthened, highly textured Ni-5 at.%W/Ni-12 at.%W composite materials prepared by a powder metallurgical approach as promising weakly magnetic substrates for coated superconductors. The key configuration of this composite substrate consists of a thin, sharp cubic textured Ni-5 at.%W layer on a Ni-12 at.%W alloy core, thus providing a mechanical reinforcement while decreasing the saturation magnetization of the whole substrate. The composite substrates have a sharp cubic texture at the top Ni-5 at.%W outer layer and their yield strength reaches 272 MPa, exceeding that of the commercially used Ni5W substrates by a factor of 1.6. The saturation magnetization of the composite substrate Ni5W/Ni12W/Ni5W is substantially reduced when compared to that of pure Ni and Ni-5 at.%W substrates, respectively

  11. Preparation and properties of Cobalt-based soft magnetic material prepared by novel powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Yogesh, E-mail: 123209001_yogesh@manit.ac.in; Srivastava, Sanjay

    2017-02-01

    The present work deals with the development of nanocrystalline 60Co–26Fe–14Al (wt%) soft magnetic materials via mechanical milling of elemental powders. The evolution of solid solution during milling proceeded with continuous decrease in atomic order and the crystallite size, and an introduction of internal strain and dislocations. The milling-induced lattice defects, crystallite size reduction, and atomic disorder exhibited a decrease in saturation magnetization, remanence magnetization, squareness ratio, and blocking temperature with increasing milling time. It has been demonstrated that, at subzero temperatures, the magnetization decreases with increasing temperature due to the development of an effective anisotropy caused by an evolution of canted spin structure owing to the introduction of lattice defects during milling. - Highlights: • Co-based HA have been fabricated by mechanical alloying. • The effect of milling time was investigated. • The saturation magnetization can be reached up to 140.79 emu/g.

  12. Oxidation and the Effects of High Temperature Exposures on Notched Fatigue Life of an Advanced Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Sudbrack, Chantal K.; Draper, Susan L.; Gorman, Timothy T.; Telesman, Jack; Gab, Timothy P.; Hull, David R.

    2012-01-01

    Oxidation and the effects of high temperature exposures on notched fatigue life were considered for a powder metallurgy processed supersolvus heat-treated ME3 disk superalloy. The isothermal static oxidation response at 704 C, 760 C, and 815 C was consistent with other chromia forming nickel-based superalloys: a TiO2-Cr2O3 external oxide formed with a branched Al2O3 internal subscale that extended into a recrystallized - dissolution layer. These surface changes can potentially impact disk durability, making layer growth rates important. Growth of the external scales and dissolution layers followed a cubic rate law, while Al2O3 subscales followed a parabolic rate law. Cr- rich M23C6 carbides at the grain boundaries dissolved to help sustain Cr2O3 growth to depths about 12 times thicker than the scale. The effect of prior exposures was examined through notched low cycle fatigue tests performed to failure in air at 704 C. Prior exposures led to pronounced debits of up to 99 % in fatigue life, where fatigue life decreased inversely with exposure time. Exposures that produced roughly equivalent 1 m thick external scales at the various isotherms showed statistically equivalent fatigue lives, establishing that surface damage drives fatigue debit, not exposure temperature. Fractographic evaluation indicated the failure mode for the pre-exposed specimens involved surface crack initiations that shifted with exposure from predominately single intergranular initiations with transgranular propagation to multi-initiations from the cracked external oxide with intergranular propagation. Weakened grain boundaries at the surface resulting from the M23C6 carbide dissolution are partially responsible for the intergranular cracking. Removing the scale and subscale while leaving a layer where M23C6 carbides were dissolved did not lead to a significant fatigue life improvement, however, also removing the M23C6 carbide dissolution layer led to nearly full recovery of life, with a

  13. Preparation of Cu and Fly Ash Composite by Powder Metallurgy Technique

    International Nuclear Information System (INIS)

    Chew, P. Y.; Lim, P. S.; Ng, M. C.; Zahi, S.; You, A. H.

    2011-01-01

    Cu and Fly Ash (FA) mixtures with different weight percentages were prepared. Pellets of the mixture powder were produced with the dimension of 17.7 mm in diameter and 10-15 mm in height. These different composites were compacted at a constant pressure of 280 MPa. One of the selected weight percentages was then compacted to form into pellet and sintered at different temperatures which were at 900, 950 and 1000 deg. C respectively for 2 hours. Density of green pellet was measured before sintered in furnace. After sintering, all the pellets with different temperatures were re-weighed and sintered density were calculated. The densification of the green and sintered pellets was required to be measured as one of the parameter in selection of the best material properties. Porosity of the pellet shall not be ignored in order to analyze the close-packed particles stacking in the pellet. SEM micrograph had been captured to observe the presence of pores and agglomeration of particles in the sample produced.

  14. Fatigue behavior of highly porous titanium produced by powder metallurgy with temporary space holders.

    Science.gov (United States)

    Özbilen, Sedat; Liebert, Daniela; Beck, Tilmann; Bram, Martin

    2016-03-01

    Porous titanium cylinders were produced with a constant amount of temporary space holder (70 vol.%). Different interstitial contents were achieved by varying the starting powders (HDH vs. gas atomized) and manufacturing method (cold compaction without organic binders vs. warm compaction of MIM feedstocks). Interstitial contents (O, C, and N) as a function of manufacturing were measured by chemical analysis. Samples contained 0.34-0.58 wt.% oxygen, which was found to have the greatest effect on mechanical properties. Quasi-static mechanical tests under compression at low strain rate were used for reference and to define parameters for cyclic compression tests. Not unexpectedly, increased oxygen content increased the yield strength of the porous titanium. Cyclic compression fatigue tests were conducted using sinusoidal loading in a servo-hydraulic testing machine. Increased oxygen content was concomitant with embrittlement of the titanium matrix, resulting in significant reduction of compression cycles before failure. For samples with 0.34 wt.% oxygen, R, σ(min) and σ(max) were varied systematically to estimate the fatigue limit (~4 million cycles). Microstructural changes induced by cyclic loading were then characterized by optical microscopy, SEM and EBSD. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Optimization of the Hot Forging Processing Parameters for Powder Metallurgy Fe-Cu-C Connecting Rods Based on Finite Element Simulation

    Science.gov (United States)

    Li, Fengxian; Yi, Jianhong; Eckert, Jürgen

    2017-12-01

    Powder forged connecting rods have the problem of non-uniform density distributions because of their complex geometric shape. The densification behaviors of powder metallurgy (PM) connecting rod preforms during hot forging processes play a significant role in optimizing the connecting rod quality. The deformation behaviors of a connecting rod preform, a Fe-3Cu-0.5C (wt pct) alloy compacted and sintered by the powder metallurgy route (PM Fe-Cu-C), were investigated using the finite element method, while damage and friction behaviors of the material were considered in the complicated forging process. The calculated results agree well with the experimental results. The relationship between the processing parameters of hot forging and the relative density of the connecting rod was revealed. The results showed that the relative density of the hot forged connecting rod at the central shank changed significantly compared with the relative density at the big end and at the small end. Moreover, the relative density of the connecting rod was sensitive to the processing parameters such as the forging velocity and the initial density of the preform. The optimum forging processing parameters were determined and presented by using an orthogonal design method. This work suggests that the processing parameters can be optimized to prepare a connecting rod with uniform density distribution and can help to better meet the requirements of the connecting rod industry.

  16. From the TRIP effect and Quenching and Partitioning steels concepts to the development of new high-performance, lean powder metallurgy steels

    International Nuclear Information System (INIS)

    Torralba, José M.; Navarro, Alfonso; Campos, Mónica

    2013-01-01

    A new method of developing lean powder metallurgy steel is proposed. The microstructure of the steel is tailored by combining two different prealloyed steel grades. These materials open a new niche in steel grades for high-performance applications by using a low-cost method of production. Moreover, an alternative route to developing microstructures suitable for manufacturing TRIP and/or Q and P steels is proposed avoiding some of the complex steps that must otherwise be taken to obtain the proper starting microstructure

  17. Study to assess the feasibility of scaling up the powder metallurgy approach for the fabrication of commercial Nb3Sn filamentary superconductors

    International Nuclear Information System (INIS)

    1977-01-01

    A preliminary assessment was made of the feasibility of scaling up the laboratory techniques of making filamentary Nb 3 Sn superconductors using powder metallurgy to commercial fabrication process. The purpose of the effort is divided into two tasks. The first one is to demonstrate that sintered niobium rods infiltrated with tin can be reduced in area of approximately 10 4 . The second task pertains to the extrusion by conventional manner a copper billet containing several sintered rods each encapsulated in tantalum. The ultimate goal of the project is to establish optimal processing parameters that are suitable for the production of long lengths of fully stabilized, large current and high field conductors

  18. Investigation of the effects of particle size on the mechanical properties of porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique

    International Nuclear Information System (INIS)

    Noman, A.

    1978-12-01

    An investigation was made of the influence of particle size on the properties of both porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique. The residual porosity, extrusion pressure, tensile strength, and ductility were found to be dependent on the particle size distribution. All of these parameters were found to increase with increasing particle size. The influence of sintering time at a temperature of 2250 0 C was also studied. With increasing sintering time, the residual porosity and tensile strength decreased, whereas the ductility increased. The procedures for fabricating infiltrated niobium rods and the various tests employed to determine their properties are described

  19. Powder Metallurgy Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The facility is uniquely equipped as the only laboratory within DA to conduct PM processing of refractory metals and alloys as well as the processing of a wide range...

  20. Application of Box-Behnken Design and Response Surface Methodology for Surface Roughness Prediction Model of CP-Ti Powder Metallurgy Components Through WEDM

    Science.gov (United States)

    Das, Arunangsu; Sarkar, Susenjit; Karanjai, Malobika; Sutradhar, Goutam

    2018-04-01

    The present work was undertaken to investigate and characterize the machining parameters (such as surface roughness, etc.) of uni-axially pressed commercially pure titanium sintered powder metallurgy components. Powder was uni-axially pressed at designated pressure of 840 MPa to form cylindrical samples and the green compacts were sintered at 0.001 mbar for about 4 h with sintering temperature varying from 1350 to 1450 °C. The influence of the sintering temperature, pulse-on and pulse-off time at wire-EDM on the surface roughness of the preforms has been investigated thoroughly. Experiments were conducted under different machining parameters in a CNC operated wire-cut EDM. The surface roughness of the machined surface was measured and critically analysed. The optimum surface roughness was achieved under the conditions of 6 μs pulse-on time, 9 μs pulse-off time and at sintering temperature of 1450 °C.

  1. Effect the addition of 10% (volume fraction) chromium on the mechanical properties of NiAlCr processed by powder metallurgy

    International Nuclear Information System (INIS)

    Garcia-Barriocanal, J.; Garces, G.; Perez, P.; Adeva, P.

    2005-01-01

    The mechanical properties of Ni 3 Al-Cr reinforced with 10% in volume fraction of chromium particles produced by powder metallurgy have been studied. For this purpose, milled powders with composition of Ni-20.9Al-8Cr-0.49B (% st.) with and without the addition of 10% in volume fraction of chromium particles have been produced. Both alloys were consolidated by hot isostatic pressing (HIP). After HIP, heat treatment was applied to homogenize the microstructure. The chromium reinforcement has an important effect in the yield strength and ultimate strength increase. The reinforced alloy presents a yield strength of 1300 MPa at room temperature with respect to 800 MPa for the un-reinforced material. After heat treatment, the yield strength of both alloys does not change significantly. However, a decrease in ductility and ultimate tensile strength have been observed. (Author) 4 refs

  2. Application of Box-Behnken Design and Response Surface Methodology for Surface Roughness Prediction Model of CP-Ti Powder Metallurgy Components Through WEDM

    Science.gov (United States)

    Das, Arunangsu; Sarkar, Susenjit; Karanjai, Malobika; Sutradhar, Goutam

    2017-06-01

    The present work was undertaken to investigate and characterize the machining parameters (such as surface roughness, etc.) of uni-axially pressed commercially pure titanium sintered powder metallurgy components. Powder was uni-axially pressed at designated pressure of 840 MPa to form cylindrical samples and the green compacts were sintered at 0.001 mbar for about 4 h with sintering temperature varying from 1350 to 1450 °C. The influence of the sintering temperature, pulse-on and pulse-off time at wire-EDM on the surface roughness of the preforms has been investigated thoroughly. Experiments were conducted under different machining parameters in a CNC operated wire-cut EDM. The surface roughness of the machined surface was measured and critically analysed. The optimum surface roughness was achieved under the conditions of 6 μs pulse-on time, 9 μs pulse-off time and at sintering temperature of 1450 °C.

  3. Data on processing of Ti-25Nb-25Zr β-titanium alloys via powder metallurgy route: Methodology, microstructure and mechanical properties.

    Science.gov (United States)

    Ueda, D; Dirras, G; Hocini, A; Tingaud, D; Ameyama, K; Langlois, P; Vrel, D; Trzaska, Z

    2018-04-01

    The data presented in this article are related to the research article entitled "Cyclic Shear behavior of conventional and harmonic structure-designed Ti-25Nb-25Zr β-titanium alloy: Back-stress hardening and twinning inhibition" (Dirras et al., 2017) [1]. The datasheet describes the methods used to fabricate two β-titanium alloys having conventional microstructure and so-called harmonic structure (HS) design via a powder metallurgy route, namely the spark plasma sintering (SPS) route. The data show the as-processed unconsolidated powder microstructures as well as the post-SPS ones. The data illustrate the mechanical response under cyclic shear loading of consolidated alloy specimens. The data show how electron back scattering diffraction(EBSD) method is used to clearly identify induced deformation features in the case of the conventional alloy.

  4. Study of the microstructural and mechanical properties of titanium-niobium-zirconium based alloys processed with hydrogen and powder metallurgy for use in dental implants

    International Nuclear Information System (INIS)

    Duvaizem, Jose Helio

    2009-01-01

    Hydrogen has been used as pulverization agent in alloys based on rare earth and transition metals due to its extremely high diffusion rate even on low temperatures. Such materials are used on hydrogen storage dispositives, generation of electricity or magnetic fields, and are produced by a process which the first step is the transformation of the alloy in fine powder by miling. Besides those, hydrogenium is also being used to obtain alloys based on titanium - niobium - zirconium in the pulverization. Powder metallurgy is utilized on the production of these alloys, making it possible to obtain structures with porous surface as result, requirement for its application as biomaterials. Other advantages of powder metallurgy usage include better surface finish and better microstructural homogeneity. In this work samples were prepared in the Ti-13Nb-13Zr composition. The hydrogenation was performed at 700 degree C, 600 degree C, and 500 degree C for titanium, niobium and zirconium respectively. After hydrogenation, the milling stage was carried out on high energy planetary ball milling with 200rpm during 90 minutes, and also in conventional ball milling for 30 hours. Samples were pressed in uniaxial press, followed by isostatic cold press, and then sintered at 1150 degree C for 7-13 hours. Microstructural properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction. Mechanical and structural properties determined were density, microhardness and moduli of elasticity. The sample sintered at 1150 degree C for 7h, hydrogenated using 10.000 mbar and produced by milling on high energy planetary ball milling presented the best mechanical properties and microstructural homogeneity. (author)

  5. Biaxially textured articles formed by power metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-26

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  6. Enhanced ductility of Mg–3Al–1Zn alloy reinforced with short length multi-walled carbon nanotubes using a powder metallurgy method

    Directory of Open Access Journals (Sweden)

    Muhammad Rashad

    2015-08-01

    Full Text Available Mg–3Al–1Zn–CNTs composites, with different weight fractions (0.25–1.0 wt% of carbon nanotubes (CNTs were successfully fabricated via a powder metallurgy method. The processing parameters were adopted in such a way to have uniform dispersion of short length CNTs without any damage, as well as refined and dissolved β phases structures throughout the composite matrix. The composite exhibited impressive increase in microhardness (about +23% and tensile failure strain value (about +98% without significant compromise in tensile strength, compared to the un-reinforced Mg–3Al–1Zn alloy. The synthesized composites can be used in automotive and aerospace industries due to their low density and high specific strength.

  7. Study to assess the feasibility of scaling up the powder metallurgy approach for the fabrication of commercial Nb/sub 3/Sn filamentary superconductors

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-09

    A preliminary assessment was made of the feasibility of scaling up the laboratory techniques of making filamentary Nb/sub 3/Sn superconductors using powder metallurgy to commercial fabrication process. The purpose of the effort is divided into two tasks. The first one is to demonstrate that sintered niobium rods infiltrated with tin can be reduced in area of approximately 10/sup 4/. The second task pertains to the extrusion by conventional manner a copper billet containing several sintered rods each encapsulated in tantalum. The ultimate goal of the project is to establish optimal processing parameters that are suitable for the production of long lengths of fully stabilized, large current and high field conductors.

  8. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al2O3 Nanocomposite Synthesized by Ball Milling and Powder Metallurgy

    Directory of Open Access Journals (Sweden)

    Meysam Toozandehjani

    2017-10-01

    Full Text Available The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al2O3 (Al-5Al2O3 has been investigated. Al-5Al2O3 nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al2O3 nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness (HV, nano-hardness (HN, and Young’s modulus (E of Al-5Al2O3 nanocomposites. HV, HN, and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively.

  9. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al₂O₃ Nanocomposite Synthesized by Ball Milling and Powder Metallurgy.

    Science.gov (United States)

    Toozandehjani, Meysam; Matori, Khamirul Amin; Ostovan, Farhad; Abdul Aziz, Sidek; Mamat, Md Shuhazlly

    2017-10-26

    The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al₂O₃ (Al-5Al₂O₃) has been investigated. Al-5Al₂O₃ nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al₂O₃ nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD) analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness ( HV ), nano-hardness ( HN ), and Young's modulus ( E ) of Al-5Al₂O₃ nanocomposites. HV , HN , and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively.

  10. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al2O3 Nanocomposite Synthesized by Ball Milling and Powder Metallurgy

    Science.gov (United States)

    Matori, Khamirul Amin; Ostovan, Farhad; Abdul Aziz, Sidek; Mamat, Md Shuhazlly

    2017-01-01

    The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al2O3 (Al-5Al2O3) has been investigated. Al-5Al2O3 nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al2O3 nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD) analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness (HV), nano-hardness (HN), and Young’s modulus (E) of Al-5Al2O3 nanocomposites. HV, HN, and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively. PMID:29072632

  11. The shielding against radiation produced by powder metallurgy with tungsten copper alloy applied on transport equipment for radio-pharmaceutical products

    International Nuclear Information System (INIS)

    Cione, Francisco C.; Sene, Frank F.; Souza, Armando C. de; Betini, Evandro G.; Rossi, Jesualdo L.; Rizzuto, Marcia A.

    2015-01-01

    Safety is mandatory on medicine radiopharmaceutical transportation and dependent on radiation shielding material. The focus of the present work is to minimize the use of harmful materials as lead and depleted uranium usually used in packages transportation. The tungsten-copper composite obtained by powder metallurgy (PM) is non-toxic. In powder metallurgy the density and the porosity of the compacted parts depends basically upon particle size distribution of each component, mixture, compacting pressure and sintering temperature cycle. The tungsten-copper composite, when used for shielding charged particles, X-rays, gamma photons or other photons of lower energy require proper interpretation of the radiation transport phenomena. The radioactive energy reduction varies according to the porosity and density of the materials used as shielding. The main factor for radiation attenuation is the cross section value for tungsten. The motivation research factor is an optimization of the tungsten and cooper composition in order to achieve the best linear absorption coefficient given by equation I (x) = I 0 e (-ux) . Experiments were conducted to quantify the effective radiation shielding properties of tungsten-copper composite produced by PM, varying the cooper amount in the composite. The studied compositions were 15%, 20% and 25% copper in mass. The Compaction pressure was 270 MPa and the sintering atmosphere was in 1.1 atm in N 2 +H 2 . The sintering temperature was 980 deg C for 2 h. The linear absorption coefficient factor was similar either for the green and the sintered compacts, due the amount of porosity did not affect the radiation attenuation. Thus the sintered was meant for size reduction and mechanical properties enhancement. (author)

  12. Comparative studies of WC-Co and WC-Co-Ni composites obtained by conventional powder metallurgy

    Directory of Open Access Journals (Sweden)

    Vinícius Martins

    2011-01-01

    Full Text Available The present work reports a comparative study of cemented carbides of compositions WC-6Co, WC-10Co, WC-20Co, WC-6Co-6Ni and WC-12Ni-6Co. The purpose was to study the powder metallurgical production process of these compositions starting from a commercial WC-6Co powder, obtaining the desired compositions by mass balance with pure Co and pure Ni powders. During the process steps mixing, milling, compacting and sintering the powders were described by its apparent density, green density, shrinkage and sintered density. Lower densities were observed in composites with higher binder content. The process was monitored by scanning electron microscopy and EDS analysis to evaluate the homogeneity of the powders, to detect contaminations by the process and to characterize the microstructure of the sintered materials. A finer microstructure was found when the binder contained Ni. Potentiodynamic polarization tests in sulfuric acid revealed pseudo-passive behavior for all the tested hard metals.

  13. Powder Metallurgy Processing of a WxTaTiVCr High-Entropy Alloy and Its Derivative Alloys for Fusion Material Applications.

    Science.gov (United States)

    Waseem, Owais Ahmed; Ryu, Ho Jin

    2017-05-16

    The W x TaTiVCr high-entropy alloy with 32at.% of tungsten (W) and its derivative alloys with 42 to 90at.% of W with in-situ TiC were prepared via the mixing of elemental W, Ta, Ti, V and Cr powders followed by spark plasma sintering for the development of reduced-activation alloys for fusion plasma-facing materials. Characterization of the sintered samples revealed a BCC lattice and a multi-phase structure. The selected-area diffraction patterns confirmed the formation of TiC in the high-entropy alloy and its derivative alloys. It revealed the development of C15 (cubic) Laves phases as well in alloys with 71 to 90at.% W. A mechanical examination of the samples revealed a more than twofold improvement in the hardness and strength due to solid-solution strengthening and dispersion strengthening. This study explored the potential of powder metallurgy processing for the fabrication of a high-entropy alloy and other derived compositions with enhanced hardness and strength.

  14. The effect of annealing temperature on the properties of powder metallurgy processed Ti-35Nb-2Zr-0.5O alloy.

    Science.gov (United States)

    Málek, Jaroslav; Hnilica, František; Veselý, Jaroslav; Smola, Bohumil; Medlín, Rostislav

    2017-11-01

    Ti-35Nb-2Zr-0.5O (wt%) alloy was prepared via a powder metallurgy process (cold isostatic pressing of blended elemental powders and subsequent sintering) with the primary aim of using it as a material for bio-applications. Sintered specimens were swaged and subsequently the influence of annealing temperature on the mechanical and structural properties was studied. Specimens were annealed at 800, 850, 900, 950, and 1000°C for 0.5h and water quenched. Significant changes in microstructure (i.e. precipitate dissolution or grain coarsening) were observed in relation to increasing annealing temperature. In correlation with those changes, the mechanical properties were also studied. The ultimate tensile strength increased from 925MPa (specimen annealed at 800°C) to 990MPa (900°C). Also the elongation increased from ~ 13% (800°C) to more than 20% (900, 950, and 1000°C). Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Phase composition, microstructure, and mechanical properties of porous Ti-Nb-Zr alloys prepared by a two-step foaming powder metallurgy method.

    Science.gov (United States)

    Rao, X; Chu, C L; Zheng, Y Y

    2014-06-01

    Porous Ti-Nb-Zr alloys with different porosities from 6.06 to 62.8% are prepared by a two-step foaming powder metallurgy method using TiH2, Nb, and Zr powders together with 0 to 50wt% of NH4HCO3. The effects of the amounts of Nb and Zr as well as the sintering temperature (1473 to 1673K) on their phase composition, porosity, morphology, and mechanical characteristics are investigated. By controlling the porosity, Nb and Zr concentrations as well as the sintering temperature, porous Ti-Nb-Zr alloys with different mechanical properties can be obtained, for example, the hardness between 290 and 63HV, the compressive strength between 1530.5 and 73.4MPa, and the elastic modulus between 10.8 and 1.2GPa. The mechanical properties of the sintered porous Ti-Nb-Zr alloys can be tailored to match different requirements for the human bones and are thus potentially useful in the hard tissue implants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Obtenção de titânio metálico com porosidade controlada por metalurgia do pó Porous titanium production and porosity control by powder metallurgy (P/M)

    OpenAIRE

    Neila de Almeida Braga; Neidenêi Gomes Ferreira; Carlos Alberto Alves Cairo

    2007-01-01

    Titanium is an attractive material for structural and biomedical applications because of its excellent corrosion resistance, biocompatibility and high strength-to-weight ratio. The high reactivity of titanium in the liquid phase makes it difficult to produce it by fusion. Powder metallurgy has been shown to be an adequate technique to obtain titanium samples at low temperatures and solid-phase consolidation. The production of compacts with different porosities obtained by uniaxial pressing an...

  17. Study of tribological properties on Al/Al2O3/MoS2 hybrid composite processed by powder metallurgy

    Directory of Open Access Journals (Sweden)

    K. Kanthavel

    2016-03-01

    Full Text Available Aluminium ceramic composites with improved mechanical and chemical properties are essential and needed in aerospace and automotive application. The aluminium matrix composite reinforced with ceramic material of alumina (Al2O3 has good tribological properties. However, aluminium based ceramic composites require improvements in their lubrication properties. In this study an attempt is made in the development of a new material through powder metallurgy technique by the addition of molybdenum disulphide (MoS2, which acts as a solid lubricant. This molybdenum disulphide (MoS2 based solid lubricant has unique advantage that it can be used in vacuum space, but the same is not applicable in case of graphite. The microstructures, material combination, wear and friction properties were analysed by scanning electron microscopy, EDX, and pin-on-disc wear tester. The newly developed aluminium composite has significant improvements in tribological properties with a combination of 5% alumina (Al2O3 and 5% molybdenum disulphide (MoS2. The test reveals that sliding distance of 1000 m and sliding speed of 1.5 m/s with applied load of 5 N result in minimum wear loss of 0.0102 g and coefficient of friction as 0.117.

  18. A new titanium based alloy Ti–27Nb–13Zr produced by powder metallurgy with biomimetic coating for use as a biomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Marcio W.D., E-mail: mwdmendes@ipen.com; Ágreda, Carola G.; Bressiani, Ana H.A.; Bressiani, José C.

    2016-06-01

    Titanium alloys are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and biocompatibility. Titanium alloys with alloying elements such as Nb and Zr are biocompatible and have Young's modulus close to that of human bone. To increase the bioactivity of titanium alloy surfaces is used chemical treatment with NaOH followed by immersion in simulated body fluid (SBF). The purpose of this study was to produce the alloy Ti–27Nb–13Zr with low Young's modulus by powder metallurgy using powders produced by the HDH process. The formation of biomimetic coatings on samples immersed in SBF for 3, 7, 11 and 15 days was evaluated. Characterization of the coating was performed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscope. The microstructure and composition of the alloy were determined using SEM and XRD, while the mechanical properties were evaluated by determining the elastic modulus and the Vickers microhardness. The sintered alloys were composed of α and β phases, equiaxed grains and with density around 97.8% of its theoretical density. The Vickers microhardness and elasticity modulus of the alloy were determined and their values indicate that this alloy can be used as a biomaterial. Analysis of the coating revealed the presence of calcium phosphate layers on samples immersed for > 3 days in the SBF solution. - Highlights: • The alloy is classified as α + β and the milling time influences the formation of these phases. • Dissolution of Nb is related to the mechanical properties of the alloy. • It's possible to form apatite on all samples immersed in SBF from 3 days. • The alloy can be used in orthopedic applications or in dental applications.

  19. Study of the mechanical stability and bioactivity of Bioglass(®) based glass-ceramic scaffolds produced via powder metallurgy-inspired technology.

    Science.gov (United States)

    Boccardi, Elena; Melli, Virginia; Catignoli, Gabriele; Altomare, Lina; Jahromi, Maryam Tavafoghi; Cerruti, Marta; Lefebvre, Louis-Philippe; De Nardo, Luigi

    2016-02-02

    Large bone defects are challenging to heal, and often require an osteoconductive and stable support to help the repair of damaged tissue. Bioglass-based scaffolds are particularly promising for this purpose due to their ability to stimulate bone regeneration. However, processing technologies adopted so far do not allow for the synthesis of scaffolds with suitable mechanical properties. Also, conventional sintering processes result in glass de-vitrification, which generates concerns about bioactivity. In this work, we studied the bioactivity and the mechanical properties of Bioglass(®) based scaffolds, produced via a powder technology inspired process. The scaffolds showed compressive strengths in the range of 5-40 MPa, i.e. in the upper range of values reported so far for these materials, had tunable porosity, in the range between 55 and 77%, and pore sizes that are optimal for bone tissue regeneration (100-500 μm). We immersed the scaffolds in simulated body fluid (SBF) for 28 d and analyzed the evolution of the scaffold mechanical properties and microstructure. Even if, after sintering, partial de-vitrification occurred, immersion in SBF caused ion release and the formation of a Ca-P coating within 2 d, which reached a thickness of 10-15 μm after 28 d. This coating contained both hydroxyapatite and an amorphous background, indicating microstructural amorphization of the base material. Scaffolds retained a good compressive strength and structural integrity also after 28 d of immersion (6 MPa compressive strength). The decrease in mechanical properties was mainly related to the increase in porosity, caused by its dissolution, rather than to the amorphization process and the formation of a Ca-P coating. These results suggest that Bioglass(®) based scaffolds produced via powder metallurgy-inspired technique are excellent candidates for bone regeneration applications.

  20. Obtenção de titânio metálico com porosidade controlada por metalurgia do pó Porous titanium production and porosity control by powder metallurgy (P/M

    Directory of Open Access Journals (Sweden)

    Neila de Almeida Braga

    2007-04-01

    Full Text Available Titanium is an attractive material for structural and biomedical applications because of its excellent corrosion resistance, biocompatibility and high strength-to-weight ratio. The high reactivity of titanium in the liquid phase makes it difficult to produce it by fusion. Powder metallurgy has been shown to be an adequate technique to obtain titanium samples at low temperatures and solid-phase consolidation. The production of compacts with different porosities obtained by uniaxial pressing and vacuum sintering is briefly reviewed. Powder particle size control has been shown to be very important for porosity control. Sample characterization was made using scanning electron microscopy (SEM images.

  1. Microstructures and Properties of 40Cu/Ag(Invar) Composites Fabricated by Powder Metallurgy and Subsequent Thermo-Mechanical Treatment

    Science.gov (United States)

    Zhang, Xin; Huang, Yingqiu; Liu, Xiangyu; Yang, Lei; Shi, Changdong; Wu, Yucheng; Tang, Wenming

    2018-03-01

    Composites of 40Cu/Ag(Invar) were prepared via pressureless sintering and subsequent thermo-mechanical treatment from raw materials of electroless Ag-plated Invar alloy powder and electrolytic Cu powder. Microstructures and properties of the prepared composites were studied to evaluate the effect of the Ag layer on blocking Cu/Invar interfacial diffusion in the composites. The electroless-plated Ag layer was dense, uniform, continuous, and bonded tightly with the Invar alloy substrate. During sintering of the composites, the Ag layer effectively prevented Cu/Invar interfacial diffusion. During cold-rolling, the Ag layer was deformed uniformly with the Invar alloy particles. The composites exhibited bi-continuous network structure and considerably improved properties. After sintering at 775 °C and subsequent thermo-mechanical treatment, the 40Cu/Ag(Invar) composites showed satisfactory comprehensive properties: relative density of 99.0 pct, hardness of HV 253, thermal conductivity of 55.7 W/(m K), and coefficient of thermal expansion of 11.2 × 10-6/K.

  2. The effects of Ti and Sn alloying elements on precipitation strengthened Cu40Zn brass using powder metallurgy and hot extrusion

    International Nuclear Information System (INIS)

    Li Shufeng; Imai, Hisashi; Atsumi, Haruhiko; Kondoh, Katsuyoshi; Kojima, Akimichi; Kosaka, Yoshiharu; Yamamoto, Koji; Takahashi, Motoi

    2012-01-01

    Highlights: ► Alloying elements Ti and Sn are proposed as additives in 60/40 brass. ► Super-saturated Ti in powder creates high chemical potential for precipitation. ► Ti is readily segregated in primary particle boundaries in BS40–1.0Ti. ► Sn was proposed as an additive to inhibit segregation of Ti in BS40–1.0Ti. ► The introduction of Sn to BS40–1.0Ti brass effectively impedes Ti segregation. - Abstract: The effects of Ti and Sn alloying elements on the microstructural and mechanical properties of 60/40 brass were studied by powder metallurgy processing. The super-saturated solid solution of Ti creates a high precipitation reaction chemical potential in water-atomized BS40-1.0Ti brass powder. Consequently, BS40–1.0Ti brass was remarkably strengthened by the addition of Ti. However, Ti readily segregated in the primary particle boundaries at elevated temperatures, which detrimentally affected the mechanical properties of BS40–1.0Ti brass. Accordingly, Sn was proposed as an additive to BS40–0.6Sn1.0Ti to inhibit the segregation of Ti. Consequently, the Ti precipitate was retained in the form of CuSn 3 Ti 5 in the interior of grains and grain boundaries rather than in the primary particle boundaries. This result demonstrates that the addition of Sn can effectively hinder Ti segregation in the primary particle boundaries. Sn addition produced significant grain refinement and mechanical strengthening effects in BS40–0.6Sn1.0Ti brass. As a result, outstanding strengthening effects were observed for BS40–0.6Sn1.0Ti sintered at 600 °C, which exhibited a yield strength of 315 MPa, an ultimate tensile strength of 598 MPa, and a Vickers micro-hardness of 216 Hv. These values represent increases of 27.5%, 20.1% and 45.6%, over those of extruded BS40–1.0Ti brass.

  3. Synthesis, mechanical properties and corrosion behavior of powder metallurgy processed Fe/Mg2Si composites for biodegradable implant applications.

    Science.gov (United States)

    Sikora-Jasinska, M; Paternoster, C; Mostaed, E; Tolouei, R; Casati, R; Vedani, M; Mantovani, D

    2017-12-01

    Recently, Fe and Fe-based alloys have shown their potential as degradable materials for biomedical applications. Nevertheless, the slow corrosion rate limits their performance in certain situations. The shift to iron matrix composites represents a possible approach, not only to improve the mechanical properties, but also to accelerate and tune the corrosion rate in a physiological environment. In this work, Fe-based composites reinforced by Mg 2 Si particles were proposed. The initial powders were prepared by different combinations of mixing and milling processes, and finally consolidated by hot rolling. The influence of the microstructure on mechanical properties and corrosion behavior of Fe/Mg 2 Si was investigated. Scanning electron microscopy and X-ray diffraction were used for the assessment of the composite structure. Tensile and hardness tests were performed to characterize the mechanical properties. Potentiodynamic and static corrosion tests were carried out to investigate the corrosion behavior in a pseudo-physiological environment. Samples with smaller Mg 2 Si particles showed a more homogenous distribution of the reinforcement. Yield and ultimate tensile strength increased when compared to those of pure Fe (from 400MPa and 416MPa to 523MPa and 630MPa, respectively). Electrochemical measurements and immersion tests indicated that the addition of Mg 2 Si could increase the corrosion rate of Fe even twice (from 0.14 to 0.28mm·year -1 ). It was found that the preparation method of the initial composite powders played a major role in the corrosion process as well as in the corrosion mechanism of the final composite. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. On the effect of TiC particles on the tensile properties and on the intrinsic two way effect of NiTi shape memory alloys produced by powder metallurgy

    International Nuclear Information System (INIS)

    Johansen, K.; Voggenreiter, H.; Eggeler, G.

    1999-01-01

    The present study investigates the tensile properties of a nickel titanium (NiTi) shape memory alloy (SMA) produced by powder metallurgy (PM) with and without TiC-particles. It discusses the effect of the addition of particles on the mechanical behavior in tension and studies the intrinsic two way effect (ε 2W ) after thermomechanical training. Special emphasis is placed on the stability of ε 2W after subsequent thermal cycling. The results are discussed on the basis of an analysis of the thermomechanical data and microstructural results. The present study shows that the PM route can produce NiTi SMAs with tensile properties which match those of materials produced by classical ingot metallurgy. Adding TiC particles to NiTi SMAs alters the phase transition temperatures (PTTs) and affects the SMA performance. Adding more than ten volume percent TiC particles results in early and brittle rupture during tensile loading. (orig.)

  5. Metallurgy Department

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The activities of the Metallurgy Department at Risø during 1981 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration...

  6. Effect of silicon carbide addition on the corrosion behavior of powder metallurgy Cu−30Zn brass in a 3.5 wt% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Almomani, Mohammed Ali, E-mail: maalmomani7@just.edu.jo [Department of Industrial Engineering, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110 (Jordan); Tyfour, Wa' il Radwan, E-mail: wrtyfou@just.edu.jo [Department of Industrial Engineering, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110 (Jordan); Nemrat, Mohammed Hani, E-mail: mohammednemrat@yahoo.com [Department of Mechanical Engineering, Institute of Applied Technology, Abu Dhabi (United Arab Emirates)

    2016-09-15

    A study was made to evaluate the corrosion behavior when Cu−30Zn alloy is reinforced with different weight fractions of silicon carbide (SiC) particles in a simulated sea solution (3.5 wt% NaCl aqueous solution). The composites were produced via powder metallurgy (PM) route. For the sake of comparison, the corrosion behaviors of unreinforced and reinforced alloy were examined. Electrochemical measurements (potentiodynamic testing) showed that the corrosion rate of the composites decreased with increase of SiC weight percentages, as a result of weak microgalvanic couple between reinforcement particles and Cu−30Zn matrix, and the low possibility of intermetallic phases formation. ANOVA test indicated that the variations of corrosion rate of the composites upon changing weight percentages of SiC particles are statistically significant. Polarization curves showed that the passive film tends to be less stable, and the potential difference between passivation and free corrosion points increased with increase of SiC weight percentages, as SiC cathodically protect the matrix material by sacrificial anodic dissolution of crevice regions about reinforcement particles. Scanning Electron Microscope (SEM) images of the sample's surfaces before and after testing are in agreement with the electrochemical results. - Highlights: • Effect of adding SiC on both uniform and localized corrosion of Cu−30Zn alloy is studied. • Reinforcing Cu−30Zn with nonconductive SiC particles decreases its tendency to uniform and localized corrosion. • Reinforcement particles cathodically protect the matrix material, and retard pit propagation to the matrix.

  7. Comparison of the microstructure and phase stability of as-cast, CAD/CAM and powder metallurgy manufactured Co-Cr dental alloys.

    Science.gov (United States)

    Li, Kai Chun; Prior, David J; Waddell, J Neil; Swain, Michael V

    2015-12-01

    The objective of this study was to identify the different microstructures produced by CC, PM and as-cast techniques for Co-Cr alloys and their phase stability following porcelain firings. Three bi-layer porcelain veneered Co-Cr specimens and one monolithic Co-Cr specimen of each alloy group [cast, powder metallurgy (PM), CAD/CAM (CC)] were manufactured and analyzed using electron backscatter diffraction (EBSD), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Specimens were treated to incremental numbers of porcelain firings (control 0, 5, 15) with crystallographic data, grain size and chemical composition subsequently obtained and analyzed. EBSD datasets of the cast alloy indicated large grains >200 μm whereas PM and CC alloy consisted of mean arithmetic grain sizes of 29.6 μm and 19.2 μm respectively. XRD and EBSD results both indicated the highest increase in hcp content (>13vol%) for cast Co-Cr alloy after treatment with porcelain firing while PM and CC indicated alloy after porcelain firing. The depth of this layer increased with porcelain firings for as-cast and PM but no significant increase (p>.05) was observed in CC. EDS line scans indicated an increase in Cr content at the alloy surface after porcelain firing treatment for all three alloys. PM and CC produced alloy had superior fcc phase stability after porcelain firings compared to a traditional cast alloy. It is recommended that PM and CC alloys be used for porcelain-fused-to-metal restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Obtainment, machining and wear of metal matrix composites processed by powder metallurgy; Obtencao, usinagem e desgaste de materiais compositos de matriz metalica processados via metalurgia do po

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Edilson Rosa Barbosa de. E-mail: erbjesus@usp.br

    1998-07-01

    The aim of this investigation was the obtainment of metal matrix composites (MMC) by the route of powder metallurgy, and the valuation of these materials with relation to their machining and wear characteristics. Firstly, were obtained pure commercial aluminium matrix composites materials, with 5, 10 and 15% volumetric fraction of silicon carbide particles. Was also obtained a material without reinforcement particles in order to verify by comparison, the influence of addition of reinforcement particles. The obtained materials were characterized physics (hydrostatic density), mechanics (hardness and tensile tests) and microstructurally (optical microscopy and scanning electron microscopy). The results showed a homogeneous distribution of reinforcement particles in the composite, and improvement in the mechanical properties, mainly tensile strength (UTS) in comparison to the unreinforced material. After, tests were made to verify the materials behavior during machining and to check the performance of several tool materials (cemented carbide, ceramics and polycrystalline diamond). In these tests, values of the cutting force were measured by instrumented tool-holders. Phenomena such as tool wear, built-up edge formation and mechanism of chip formation were also observed and evaluated. The results from the cemented carbide tool tests, were utilised for the machinability index determination of each material. These results were applied to the Taylor equation and the equation constants for each material and test conditions were determined. The results showed that the inclusion of silicon carbide particles made extremely difficult the machining of the composites, and only with diamond tool, satisfactory results were obtained. At last, wear tests were performed to verify the influence of the reinforcement particles in the characteristics of wear resistance of the materials. The results obtained were utilized in the wear coefficient determination for each material. The

  9. Synthesis of Al₂Ca Dispersoids by Powder Metallurgy Using a Mg-Al Alloy and CaO Particles.

    Science.gov (United States)

    Fujita, Junji; Umeda, Junko; Kondoh, Katsuyoshi

    2017-06-28

    The elemental mixture of Mg-6 wt %Al-1 wt %Zn-0.3 wt %Mn (AZ61B) alloy powder and CaO particles was consolidated by an equal-channel angular bulk mechanical alloying (ECABMA) process to form a composite precursor. Subsequently, the precursor was subjected to a heat treatment to synthesize fine Al₂Ca particles via a solid-state reaction between the Mg-Al matrix and CaO additives. Scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and electron probe micro-analysis on the precursor indicated that 4.7-at % Al atoms formed a supersaturated solid solution in the α-Mg matrix. Transmission electron microscopy-EDS and X-ray diffraction analyses on the AZ61B composite precursor with 10-vol % CaO particles obtained by heat treatment confirmed that CaO additives were thermally decomposed in the Mg-Al alloy, and the solid-soluted Ca atoms diffused along the α-Mg grain boundaries. Al atoms also diffused to the grain boundaries because of attraction to the Ca atoms resulting from a strong reactivity between Al and Ca. As a result, needle-like (Mg,Al)₂Ca intermetallics were formed as intermediate precipitates in the initial reaction stage during the heat treatment. Finally, the precipitates were transformed into spherical Al₂Ca particles by the substitution of Al atoms for Mg atoms in (Mg,Al)₂Ca after a long heat treatment.

  10. Use of Cold Gas Dynamic Spraying of bi-metallic powder mixtures as alternative to classic powder metallurgy route for producing intermetallic materials

    Directory of Open Access Journals (Sweden)

    Vit Jan

    2016-06-01

    Full Text Available The paper presents cold gas dynamic spraying (or Cold Spray as a novel surface treatment technology capable not only of surface modifications but also being used as bulk creating technology. This is demonstrated on numerous samples where bi-metallic powder feedstock is deposited into bulk, self-standing pieces of material that does not need the support of substrate. Mixtures from the group of Fe, Al, Ti, Ni, Cu were used for the initial bi-metallic mixtures. The deposited samples were then subjected to annealing at temperatures ranging from 300 to 1100°C in protective atmosphere and resulting morphologies and microstructures were analysed. Generally materials with high proportion of intermetallic phase content were obtained. These are discussed as potential scaffolds for metal or polymer matrix composites or as hi temperature resistive supports for catalysts with filter functions.

  11. Study on effects of powder and flake chemistry and morphology on the properties of Al-Cu-Mg-X-X-X powder metallurgy advanced aluminum alloys

    Science.gov (United States)

    Meschter, P. J.; Lederich, R. J.; Oneal, J. E.; Pao, P. S.

    1985-01-01

    The effects of alloy chemistry and particulate morphology on consolidation behavior and consolidated product properties in rapid solidification processed, powder-metallurgical Al-3Li-1.5Cu-1Mg-0.5Co-0.2Zr and Al-4.4Cu-1.5Mg-Fe-Ni-0.2Zr extrusions and forgings were studied. Microstructures and mechanical properties of both alloys are largely unaffected by particulate production method (vacuum atomization, ultrasonic atomization, or twin-roller quenching) and by particulate solidification rates between 1000 and 100,000 K/s. Consolidation processing by canning, cold compaction, degassing, and hot extrusion is sufficient to yield mechanical properties in the non-Li-containing alloy extrusions which are similar to those of 7075-Al, but ductilities and fracture toughnesses are inferior owing to poor interparticle bonding caused by lack of a vacuum-hot-pressing step during consolidation. Mechanical properties of extrusions are superior to those of forgings owing to the stronger textures produced by the more severe hot working during extrusion. The effects on mechanical properties of dispersoid size and volume fraction, substructural refinement, solid solution strengthening by Mg, and precipitate size and distribution are elucidated for both alloy types.

  12. Implantation metallurgy

    International Nuclear Information System (INIS)

    Picraux, S.T.

    1975-01-01

    Important changes in the near-surface physical properties of metals were obtained by high-fluence ion implantation. Recently there have been an increasing number of studies of the behavior of implanted species with the aim of understanding the detailed physical processes that occur in an implanted metal layer. A key aspect of these implantation metallurgy studies has been the ability to form uniquely controlled systems in the near-surface regions of metals that can be studied with accurate depth resolution. Metallurgical parameters that may be difficult or impossible to obtain by other means can be measured. Also, parameters that depend on the implantation process, due to the athermal introduction of atoms and defects can be determined. Thus the dual objective of implantation metallurgy is to obtain information to improve understanding of the microscopic aspects of metallurgy and to understand how to form controlled new metallurgical systems. Examples of parameters studied include implanted impurity location, diffusion, enhanced diffusion, solubility, precipitation, and dissolution. (auth)

  13. Influence of sub-solvus solution heat treatment on γ′ morphological instability in a new Ni–Cr–Co-based powder metallurgy superalloy

    International Nuclear Information System (INIS)

    Yang, W.P.; Liu, G.Q.; Wu, K.; Hu, B.F.

    2014-01-01

    Highlights: • A special γ′ morphological instability in a new Ni–Cr–Co-based P/M superalloy was studied. • Three heat treatments were applied to the alloy and microstructures were observed. • Microstructure of the alloy was homogenized by sub-solvus solution heat treatment. • Sub-solvus solution heat treatment influences morphology of γ′ fan-type structures. • Sub-solvus solution heat treatment makes γ′ fan-type structures regular and stable. -- Abstract: The influence of the sub-solvus solution heat treatment on the microstructure, especially the γ′ morphology (γ′ fan-type structure), and microhardness of a new Ni–Cr–Co-based powder metallurgy superalloy was studied by means of field emission scanning electron microscopy (FESEM) and microhardness testing. The results show that sub-solvus solution heat treatment changes the microstructure of an as-forged alloy. It makes large primary γ′ phases at grain boundaries smaller and the distribution of secondary γ′ phases in the interior of the grains more homogeneous. Moreover, the grain boundaries widen because of the supplementary precipitate. The sub-solvus solution heat treatment before the super-solvus solution heat treatment does not change nucleation sites of the γ′ fan-type structures which precipitate during the super-solvus solution heat treatment. However, it influences the morphology of γ′ fan-type structures. Length distribution of the secondary γ′ dendrites in fan-type structures changes from a bimodal to a unimodal distribution, which means the lengths of the secondary γ′ dendrites become more uniform. Applying a sub-solvus solution heat treatment after the super-solvus solution heat treatment causes the secondary γ′ dendrites to be broken off in the fan-type structures and a refinement of the γ′ phases, and this improves stability of the γ′ phases

  14. Processing of W-Cu functionally graded materials (FGM) through the powder metallurgy route: application as plasma facing components for ITER-like thermonuclear fusion reactor; Elaboration de materiaux W-Cu a gradient de proprietes fonctionnelles (FGM) par metallurgie des poudres: application en tant que composants face au plasma de machines de fusion thermonucleaire de type Iter

    Energy Technology Data Exchange (ETDEWEB)

    Raharijaona, J.J.

    2009-11-15

    The aim of this study was to study and optimize the sintering of W-Cu graded composition materials, for first wall of ITER-like thermonuclear reactor application. The graded composition in the material generates graded functional properties (Functionally Graded Materials - FGM). Rough thermomechanical calculations have shown the interest of W-Cu FGM to improve the lifetime of Plasma Facing Components (PFC). To process W-Cu FGM, powder metallurgy route was analyzed and optimized from W-CuO powder mixtures. The influence of oxide reduction on the sintering of powder mixtures was highlighted. An optimal heating treatment under He/H{sub 2} atmosphere was determined. The sintering mechanisms were deduced from the analysis of the effect of the Cu-content. Sintering of W-Cu materials with a graded composition and grain size has revealed two liquid migration steps: i) capillary migration, after the Cu-melting and, ii) expulsion of liquid, at the end of sintering, from the dense part to the porous part, due to the continuation of W-skeleton sintering. These two steps were confirmed by a model based on capillary pressure calculation. In addition, thermal conductivity measurements were conducted on sintered parts and showed values which gradually increase with the Cu-content. Hardness tests on a polished cross-section in the bulk are consistent with the composition profiles obtained and the differential grain size. (author)

  15. Fracture behaviour of Cu-Al-Ni shape memory alloys obtained by powder metallurgy; Comportamiento a fractura de aleaciones pulvimetalurgicas de Cu-Al-Ni con efecto memoria de forma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, P. P.; Perez-Saez, R. B.; Recarte, V.; San Juan, J.M.; Ruano, O. A.; No, M. L.

    2001-07-01

    Polycrystalline Cu-Al-Ni shape memory alloys have been scarcely employed for technological applications due to their high brittleness. The development of a new elaboration technique based on powder metallurgy has recently overcome this problem, through the improvement of the ductility of the produced alloys without affecting its shape memory properties. The fracture behaviour of an alloy obtained using the elaboration technique has been studied by means of Scanning Electron Microscopy and mechanical testing. The results show a ductile fracture with a maximum strain close to 13%, which is the best fracture behaviour obtained for Cu-Al-Ni polycrystals. The microstructure of such alloys ha been studied by means of Transmission Electron Microscopy, showing a poligonyzed structure in which martensite plated passing through the subboundaries easily. (Author) 19 refs.

  16. Effect of process control agent on the porous structure and mechanical properties of a biomedical Ti-Sn-Nb alloy produced by powder metallurgy.

    Science.gov (United States)

    Nouri, A; Hodgson, P D; Wen, C E

    2010-04-01

    The influence of different amounts and types of process control agent (PCA), i.e., stearic acid and ethylene bis-stearamide, on the porous structure and mechanical properties of a biomedical Ti-16Sn-4Nb (wt.%) alloy was investigated. Alloy synthesis was performed on elemental metal powders using high-energy ball milling for 5h. Results indicated that varying the PCA content during ball milling led to a drastic change in morphology and particle-size distribution of the ball-milled powders. Porous titanium alloy samples sintered from the powders ball milled with the addition of various amounts of PCA also revealed different pore morphology and porosity. The Vickers hardness of the sintered titanium alloy samples exhibited a considerable increase with increasing PCA content. Moreover, the addition of larger amounts of PCA in the powder mixture resulted in a significant increase in the elastic modulus and peak stress for the sintered porous titanium alloy samples under compression. It should also be mentioned that the addition of PCA introduced contamination (mainly carbon and oxygen) into the sintered porous product. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

  17. Application of rapid solidification powder metallurgy processing to prepare Cu–Al–Ni high temperature shape memory alloy strips with high strength and high ductility

    Energy Technology Data Exchange (ETDEWEB)

    Vajpai, S.K., E-mail: vajpaisk@gmail.com [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India); Dube, R.K., E-mail: rkd@iitk.ac.in [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India); Sangal, S., E-mail: sangals@iitk.ac.in [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India)

    2013-05-15

    Cu–Al–Ni high temperature shape memory alloy (HTSMA) strips were successfully prepared from rapid solidified water atomized Cu–Al–Ni pre-alloyed powders via hot densification rolling of unsheathed sintered powder preforms. Finished heat-treated Cu–Al–Ni alloy strips had fine-grained structure, average grain size approximately 16 μm, and exhibited a combination of high strength and high ductility. It has been demonstrated that the redistribution of nano-sized alumina particles, present on the surface as well as inside the starting water atomized Cu–Al–Ni pre-alloyed powder particles, due to plastic deformation of starting powder particles during hot densification rolling resulted in the fine grained microstructure in the finished SMA strips. The finished SMA strips were almost fully martensitic in nature, consisting of a mixture of β{sub 1}{sup ′} and γ{sub 1}{sup ′} martensite. The average fracture strength and fracture strain of the finished SMA strips were 810 MPa and 12%, respectively, and the fractured specimens exhibited primarily micro-void coalescence type ductile nature of fracture. Finished Cu–Al–Ni SMA strips exhibited high characteristic transformation temperatures and an almost 100% one-way shape recovery was obtained in the specimens up to 4% applied deformation pre-strain. The retained two-way shape memory recovery increased with increasing applied training pre-strain, achieving a maximum value of 16.25% at 5% applied training pre-strain.

  18. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2017-04-01

    Full Text Available A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt % were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA route followed by spark plasma sintering (SPS and rapid cooling. Neutron Powder Diffraction (NPD, Electron Back Scattering Diffraction (EBSD, and Transmission Electron Microscopy (TEM were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  19. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Science.gov (United States)

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J.; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-01-01

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process. PMID:28772747

  20. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy.

    Science.gov (United States)

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-04-06

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5-2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni₃Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo₂C particles during sintering. The amount of grain boundaries greatly increases the Hall-Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  1. A Comparison of the Plastic-Flow Response of a Powder-Metallurgy Nickel-Base Superalloy Under Nominally-Isothermal and Transient-Heating Hot-Working Conditions

    Science.gov (United States)

    Semiatin, S. L.; Mahaffey, D. W.; Tung, D. J.; Zhang, W.; Senkov, O. N.

    2017-04-01

    The flow-stress behavior at hot-working temperatures and strain rates of the powder-metallurgy superalloy LSHR was determined under nominally-isothermal and transient-heating conditions. Two conventional methods, compression of right-circular cylinders and torsion of thin-walled tubes, were used for isothermal tests. A direct-resistance-heating technique utilizing torsion of round-bar specimens in a Gleeble® machine was applied for both isothermal and transient-heating conditions. When expressed in terms of effective stress and strain, baseline data determined by the two conventional methods showed good agreement. With the aid of a flow-localization analysis to assess the confounding influence of axial (and radial) temperature gradients on deformation uniformity, the flow stresses determined from nominally-isothermal Gleeble® torsion tests were shown to be broadly similar to those from the conventional tests. With regard to transient phenomena, Gleeble® tests were also useful in quantifying the effect of rapid heating and short soak time on the observed higher flow stress associated with a metastable microstructure. The present work also introduces two new test techniques using direct-resistance-heated torsion specimens. One involves continuous heating under constant-torque conditions, and the other comprises testing an individual specimen at a series of temperatures and strain rates. Using a single specimen, the former method enabled the determination of the apparent activation energy for plastic flow, which was similar to that determined from the series of isothermal tests; the latter provided a low-cost, high-throughput approach to quantify the flow behavior.

  2. Effect of Pre-Oxidation Treatment of Nano-SiC Particulates on Microstructure and Mechanical Properties of SiC/Mg-8Al-1Sn Composites Fabricated by Powder Metallurgy Combined with Hot Extrusion.

    Science.gov (United States)

    Li, Chuan-Peng; Wang, Zhi-Guo; Zha, Min; Wang, Cheng; Yu, Hong-Chen; Wang, Hui-Yuan; Jiang, Qi-Chuan

    2016-11-26

    Nano-SiC particulates (n-SiC p ) reinforced Mg-8Al-1Sn (AT81) composites with different pre-oxidation parameters were fabricated by powder metallurgy (P/M) process combined with hot extrusion. The effects of pre-oxidization treatment of n-SiC p on the microstructure and tensile properties of 0.5 vol % n-SiC p /AT81 composites were investigated accordingly. The distribution of n-SiC p with different pre-oxidation parameters was homogeneous in the composites. Moreover, it was found that a thin MgAl₂O₄ layer formed at the interface when the n-SiC p were pre-oxidized at 1073 K for 2 h, while the MgAl₂O₄ layer became much thicker with pre-oxidization temperature increasing to 1273 K for 2 h. After an appropriate pre-oxidization treatment of n-SiC p at 1073 K for 2 h, the as-extruded 0.5 vol % n-SiC p /AT81 composites exhibited an enhanced strength. It was found that the yield strength (YS) and ultimate tensile strength (UTS) increased from 168 MPa and 311 MPa to 255 MPa and 393 MPa compared with the as-extruded AT81 alloy, reflecting 51.8% and 26.4% increments, respectively. The improvement of mechanical properties should be mainly attributed to the grain refinement and homogeneous distribution of n-SiC p in the composites. Moreover, a well-bonded interface and the formation of an appropriate amount of interfacial product (MgAl₂O₄) benefited the material's mechanical properties.

  3. Spherical rhenium metal powder

    International Nuclear Information System (INIS)

    Leonhardt, T.; Moore, N.; Hamister, M.

    2001-01-01

    The development of a high-density, spherical rhenium powder (SReP) possessing excellent flow characteristics has enabled the use of advanced processing techniques for the manufacture of rhenium components. The techniques that were investigated were vacuum plasma spraying (VPS), direct-hot isostatic pressing (D-HIP), and various other traditional powder metallurgy processing methods of forming rhenium powder into near-net shaped components. The principal disadvantages of standard rhenium metal powder (RMP) for advanced consolidation applications include: poor flow characteristics; high oxygen content; and low and varying packing densities. SReP will lower costs, reduce processing times, and improve yields when manufacturing powder metallurgy rhenium components. The results of the powder characterization of spherical rhenium powder and the consolidation of the SReP are further discussed. (author)

  4. Metallurgy and properties of plasma spray formed materials

    Science.gov (United States)

    Mckechnie, T. N.; Liaw, Y. K.; Zimmerman, F. R.; Poorman, R. M.

    1992-01-01

    Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure.

  5. Effect the addition of 10% (volume fraction) chromium on the mechanical properties of NiAlCr processed by powder metallurgy; Efecto de la adicion de un 10% en volumen de cromo en el comportamiento a traccion de aleaciones pulvimetalurgicas NiAlCr

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Barriocanal, J.; Garces, G.; Perez, P.; Adeva, P.

    2005-07-01

    The mechanical properties of Ni{sub 3}Al-Cr reinforced with 10% in volume fraction of chromium particles produced by powder metallurgy have been studied. For this purpose, milled powders with composition of Ni-20.9Al-8Cr-0.49B (% st.) with and without the addition of 10% in volume fraction of chromium particles have been produced. Both alloys were consolidated by hot isostatic pressing (HIP). After HIP, heat treatment was applied to homogenize the microstructure. The chromium reinforcement has an important effect in the yield strength and ultimate strength increase. The reinforced alloy presents a yield strength of 1300 MPa at room temperature with respect to 800 MPa for the un-reinforced material. After heat treatment, the yield strength of both alloys does not change significantly. However, a decrease in ductility and ultimate tensile strength have been observed. (Author) 4 refs.

  6. Metallurgy Department publications 1988

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

    1989-08-01

    A presentation (including abstracts) of scientific and technical publications and lectures by the staff of the Metallurgy Department during 1988 is given. The list comprises journal papers, conference papers, reports, lectures and poster presentations in the following catagories: Publications, Lectures and Poster Presentations. (author)

  7. Metallurgy Department publications 1989

    International Nuclear Information System (INIS)

    Horsewell, A.

    1990-08-01

    All publiclations by the staff of the Metallurgy Department during 1989 are listed. This list is divided into three sections as follows: Publications (journal and conference papers, reports); Lectures (public lecture presentations) and Posters (poster presentations at conferences and symposia). Abstracts are included. (author)

  8. Extractive metallurgy. Recent advances

    International Nuclear Information System (INIS)

    Stevenson, E.J.

    1977-01-01

    Detailed technical information derived from patents issued since 1975 on extractive metallurgy is presented. In part one, concerning copper, the major areas covered are: smelting and roasting; acid leaching; ammonia leach processes; cuprous chloride and ferric chloride; and recovery of copper values from solution. Part two covers other metals, including: nickel and cobalt; ocean floor nodules; lead, zinc, molybdenum and manganese; precious metals; and uranium titanium, tantalum, rhenium, gallium, and other metals

  9. Study of the microstructural and mechanical properties of titanium-niobium-zirconium based alloys processed with hydrogen and powder metallurgy for use in dental implants; Estudo das propriedades mecanicas e microestruturais de ligas a base de titanio-niobiozirconio processados com hidrogenio e metalurgia do po para utilizacao em implantes dentarios

    Energy Technology Data Exchange (ETDEWEB)

    Duvaizem, Jose Helio

    2009-07-01

    Hydrogen has been used as pulverization agent in alloys based on rare earth and transition metals due to its extremely high diffusion rate even on low temperatures. Such materials are used on hydrogen storage dispositives, generation of electricity or magnetic fields, and are produced by a process which the first step is the transformation of the alloy in fine powder by miling. Besides those, hydrogenium is also being used to obtain alloys based on titanium - niobium - zirconium in the pulverization. Powder metallurgy is utilized on the production of these alloys, making it possible to obtain structures with porous surface as result, requirement for its application as biomaterials. Other advantages of powder metallurgy usage include better surface finish and better microstructural homogeneity. In this work samples were prepared in the Ti-13Nb-13Zr composition. The hydrogenation was performed at 700 degree C, 600 degree C, and 500 degree C for titanium, niobium and zirconium respectively. After hydrogenation, the milling stage was carried out on high energy planetary ball milling with 200rpm during 90 minutes, and also in conventional ball milling for 30 hours. Samples were pressed in uniaxial press, followed by isostatic cold press, and then sintered at 1150 degree C for 7-13 hours. Microstructural properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction. Mechanical and structural properties determined were density, microhardness and moduli of elasticity. The sample sintered at 1150 degree C for 7h, hydrogenated using 10.000 mbar and produced by milling on high energy planetary ball milling presented the best mechanical properties and microstructural homogeneity. (author)

  10. Measurement of loose powder density

    International Nuclear Information System (INIS)

    Akhtar, S.; Ali, A.; Haider, A.; Farooque, M.

    2011-01-01

    Powder metallurgy is a conventional technique for making engineering articles from powders. Main objective is to produce final products with the highest possible uniform density, which depends on the initial loose powder characteristics. Producing, handling, characterizing and compacting materials in loose powder form are part of the manufacturing processes. Density of loose metallic or ceramic powder is an important parameter for die design. Loose powder density is required for calculating the exact mass of powder to fill the die cavity for producing intended green density of the powder compact. To fulfill this requirement of powder metallurgical processing, a loose powder density meter as per ASTM standards is designed and fabricated for measurement of density. The density of free flowing metallic powders can be determined using Hall flow meter funnel and density cup of 25 cm/sup 3/ volume. Density of metal powders like cobalt, manganese, spherical bronze and pure iron is measured and results are obtained with 99.9% accuracy. (author)

  11. Power metallurgy approaches to high temperature components for gas turbine engines

    Science.gov (United States)

    Probst, H. B.

    1974-01-01

    Work conducted by NASA and NASA contractors on prealloyed superalloy powders and materials strengthened by oxide dispersion is reviewed. Fabrication, tensile strength, superplasticity, grain growth control, stress rupture life, and grain-size and dispersion-level effects are covered. Distinct strength advantages of powder metallurgy superalloys over conventional wrought alloys are noted.

  12. Current programmes of Metallurgy Division (1991)

    International Nuclear Information System (INIS)

    1991-01-01

    Current research and development programmes of the Metallurgy Division are listed under the headings: 1)Thrust Areas, 2)High Temperature Materials Section, 3)Chemical Metallurgy Section, 4)Metallurgical Thermochemistry Section, 5)Physical Metallurgy Section, 6)Mechanical Metallurgy Section, 7)Corrosion Metallurgy Section, 8)Electrochemical Science and Technology Section, 9)Ceramics Section, and 10)Fabrication and Maintenance Group. A list of equipment in the Division and a list of sciientific personnel of the Division are also given. (M.G.B.)

  13. Lithium extractive metallurgy

    International Nuclear Information System (INIS)

    Josa, J.M.; Merino, J.L.

    1985-01-01

    The Nuclear Fusion National Program depends on lithium supplies. Extractive metallurgy development is subordinate to the localization and evaluation of ore resources. Nowadays lithium raw materials usable with present technology consist of pegmatite ore and brine. The Instituto Geologico y Minero Espanol (IGME) found lepidolite, ambligonite and spodrimene in pegmatite ores in different areas of Spain. However, an evaluation of resources has not been made. Different Spanish surface and underground brines are to be sampled and analyzed. If none of these contain significant levels of lithium, the Junta de Energia Nuclear (JEN) will try an agreement with IGME for ENUSA (Empresa Nacional del Uranio, S.A.) to explore pegmatite-ore bodies from different locations. Different work stages, laboratory tests, pilots plants tests and commercial plant, are foreseen, if the deposits are found. (author)

  14. Development of an alternative route for recycling AA2050 aluminum alloy by powder metallurgy; Desenvolvimento de uma rota alternativa para reciclagem da liga de aluminio AA2050 via metalurgia do po

    Energy Technology Data Exchange (ETDEWEB)

    Guido, V.; Oliveira, A.C. de; Travessa, D.N.; Cardoso, K.R., E-mail: vane.guid@gmail.com [Universidade Federal de Sao Paulo (USP), Sao Jose dos Campos, SP (Brazil). Instituto de Ciencia e Tecnologia

    2014-07-01

    This paper presents an alternative solid state route to recycling AA2050 aeronautical aluminium alloy chips. The first stage in the recycling process, reported in this work, is the obtainment of the alloy powder by high energy ball milling to subsequent cold pressing and hot extrusion. The process started with the cleaning of chips with the aim of contaminant removing from machining process and transport, followed by the high energy ball milling to result in the AA2050 alloy powder. The powder obtained was characterized by laser size particle analysis, scanning electron microscopy (SEM), X-Ray diffraction (DRX) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results show the feasibility of obtaining a powder having appropriate particle size and chemical composition in accordance with the specification for alloy. (author)

  15. Characterization of Ni{sub 5}3.5-Fe{sub 1}9.5-Ga{sub 2}7 Ni{sub 5}3.5 ferromagnetic shape memory alloy produced by powder metallurgy; Caracterizacion de la aleacion Ni{sub 5}3.5-Fe{sub 1}9.5-Ga{sub 2}7 con memoria de forma ferromagnetica producida por metalurgia de polvos

    Energy Technology Data Exchange (ETDEWEB)

    Olmos, L.; Alvarado-Hernandez, F.; Omar Jimenez, H.; Vergara-Hernandez, J.; Arroyo Albiter, M.; Ochoa-Gamboa, R. A.

    2015-07-01

    The main drawback of ferromagnetic shape memory alloys fabricated through casting methods are its brittleness. In order to overcome this disadvantage, powder metallurgy is an ideal technique for the consolidation of many engineering parts. This paper is focused on the study of the milling and sintering effects of metallic powders over the evolution of the crystalline phases responsibly for the shape memory effect of these materials. To achieve this objective, ferromagnetic shape memory alloy powders (Ni{sub 5}3.5-Fe{sub 1}9.5-Ga{sub 2}7) were prepared from a cast ingot by mechanical milling at two different times of 30 and 60 minutes. The evolution of the phases was investigated through high temperature X-ray diffraction (HTXRD), whereas sintering was analyzed with dilatometry tests. X-ray studies showed that four different phases can be present depending on the particle size and temperature at which the heat treatment was performed. Coarser powders showed a B2 structure along with a γ phase while the finer showed a L21 structure when treated below 1173 K. Furthermore, finer powders had a modulated M14 martensitic structure after sintering at temperatures above 1273 K. The sintering of powders was slow and a mass diffusion mechanism was not clearly observed. (Author)

  16. Improvement of the mechanical properties and corrosion resistance of biodegradable β-Ca3(PO4)2/Mg-Zn composites prepared by powder metallurgy: the adding β-Ca3(PO4)2,hot extrusion and aging treatment.

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Deng, Youwen; Dai, Han; Dai, Yilong; Xiong, Hanqing; Fang, Hongjie

    2017-05-01

    In this study, 10%β-Ca 3 (PO 4 ) 2 /Mg-6%Zn (wt.%) composites with Mg-6%Zn alloy as control were prepared by powder metallurgy. After hot extrusion, the as-extruded composites were aged for 72h at 150°C. The effects of the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment on their microstructure, mechanical properties and corrosion resistance were investigated. The XRD results identified α-Mg, MgZn phase and β-Ca 3 (PO 4 ) 2 phase in these composites. After hot extrusion, grains were significantly refined, and the larger-sized β-Ca 3 (PO 4 ) 2 particles and coarse MgZn phases were broken into linear-distributed β-Ca 3 (PO 4 ) 2 and MgZn phases along the extrusion direction. After aging treatment, the elements of Zn, Ca, P and O presented a more homogeneous distribution. The compressive strengths of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites were approximately double those of natural bone, and their densities and elastic moduli matched those of natural bone. The immersion tests and electrochemical tests revealed that the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment could promote the formation of protective corrosion product layer on the sample surface in Ringer's solution, which improved corrosion resistance of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites. The XRD results indicated that the corrosion product layer contained Mg(OH) 2 , β-Ca 3 (PO 4 ) 2 and hydroxyapatite (HA). The cytotoxicity assessments showed the as-extruded β-Ca 3 (PO 4 ) 2 /Mg-Zn composite aged for 72h was harmless to L-929 cells. These results suggested that the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites prepared by powder metallurgy were promising to be used for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The extractive metallurgy of gold

    Energy Technology Data Exchange (ETDEWEB)

    Kongolo, K.; Mwema, M.D. [University of Lubumbashi, Zaire, Gecamines Metallurgical Research Centre, Likasi, Zaire, c/o Gecamines Brussels (Belgium)

    1998-12-15

    Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied.

  18. The extractive metallurgy of gold

    International Nuclear Information System (INIS)

    Kongolo, K.; Mwema, M.D.

    1998-01-01

    Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied

  19. Characterization and Sintering of Armstrong Process Titanium Powder

    Science.gov (United States)

    Xu, Xiaoyan; Nash, Philip; Mangabhai, Damien

    2017-04-01

    Titanium and titanium alloys have a high strength to weight ratio and good corrosion resistance but also need longer time and have a higher cost on machining. Powder metallurgy offers a viable approach to produce near net-shape complex components with little or no machining. The Armstrong titanium powders are produced by direct reduction of TiCl4 vapor with liquid sodium, a process which has a relatively low cost. This paper presents a systematic research on powder characterization, mechanical properties, and sintering behavior and of Armstrong process powder metallurgy, and also discusses the sodium issue, and the advantages and disadvantages of Armstrong process powders.

  20. Physical metallurgy of nickel aluminides

    Indian Academy of Sciences (India)

    A description of the important physical metallurgy aspects of Ni$_3Al and NiAl encompassing structure, crystallographic defects, slip systems and phase stability has been presented in this article. The microstructures generated in the two alloys by conventional as well as novel processing techniques have been discussed.

  1. Effect of Heat Treatment on the Microstructure and Wear Properties of Al-Zn-Mg-Cu/In-Situ Al-9Si-SiCp/Pure Al Composite by Powder Metallurgy

    Science.gov (United States)

    Yu, Byung Chul; Bae, Ki-Chang; Jung, Je Ki; Kim, Yong-Hwan; Park, Yong Ho

    2018-03-01

    This study examined the effects of heat treatment on the microstructure and wear properties of Al-Zn-Mg-Cu/in-situ Al-9Si-SiCp/pure Al composites. Pure Al powder was used to increase densification but it resulted in heterogeneous precipitation as well as differences in hardness among the grains. Heat treatment was conducted to solve this problem. The heat treatment process consisted of three stages: solution treatment, quenching, and aging treatment. After the solution treatment, the main dissolved phases were η'(Mg4Zn7), η(MgZn2), and Al2Cu phase. An aging treatment was conducted over the temperature range, 100-240 °C, for various times. The GP zone and η'(Mg4Zn7) phase precipitated at a low aging temperature of 100-160 °C, whereas the η(MgZn2) phase precipitated at a high aging temperature of 200-240 °C. The hardness of the sample aged at 100-160 °C was higher than that aged at 200-240 °C. The wear test was conducted under various linear speeds with a load of 100 N. The aged composite showed a lower wear rate than that of the as-sintered composite under all conditions. As the linear speed was increased to 1.0 m/s, the predominant wear behavior changed from abrasive to adhesive wear in all composites.

  2. Powder technology

    International Nuclear Information System (INIS)

    Agueda, Horacio

    1989-01-01

    Powder technology is experiencing nowadays a great development and has broad application in different fields: nuclear energy, medicine, new energy sources, industrial and home artifacts, etc. Ceramic materials are of daily use as tableware and also in the building industry (bricks, tiles, etc.). However, in machine construction its utilization is not so common. The same happens with metals: powder metallurgy is employed less than traditional metal forming techniques. Both cases deal with powder technology and the forming techniques as far as the final consolidation through sintering processes are very similar. There are many different methods and techniques in the forming stage: cold-pressing, slip casting, injection molding, extrusion molding, isostatic pressing, hot-pressing (which involves also the final consolidation step), etc. This variety allows to obtain almost any desired form no matter how complex it could be. Some applications are very specific as in the case of UO 2 pellets (used as nuclear fuels) but with the same technique and other materials, it is possible to manufacture a great number of different products. This work shows the characteristics and behaviour of two magnetic ceramic materials (ferrites) fabricated in the laboratory of the Applied Research Division of the Bariloche Atomic Center for different purposes. Other materials and products made with the same method are also mentioned. Likewise, densities and shrinkage obtained by different methods of forming (cold-pressing, injection molding, slip casting and extrusion molding) using high-purity alumina (99.5% Al 2 O 3 ). Finally, different applications of such methods are given. (Author) [es

  3. Oxidation characteristics of porous-nickel prepared by powder metallurgy and cast-nickel at 1273 K in air for total oxidation time of 100 h.

    Science.gov (United States)

    Mohamed, Lamiaa Z; Ghanem, Wafaa A; El Kady, Omayma A; Lotfy, Mohamed M; Ahmed, Hafiz A; Elrefaie, Fawzi A

    2017-11-01

    The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravimetrically. The topography and the cross-section microstructure of each oxidized sample were observed using optical and scanning electron microscopy. X-ray diffractometry and X-ray energy dispersive analysis were used to determine the nature of the formed oxide phases. The kinetic results revealed that the porous-nickel samples had higher trend for irreproducibility. The average oxidation rate for porous- and cast-nickel samples was initially rapid, and then decreased gradually to become linear. Linear rate constants were 5.5 × 10 -8  g/cm 2  s and 3.4 × 10 -8  g/cm 2  s for the porous- and cast-nickel samples, respectively. Initially a single-porous non-adherent NiO layer was noticed on the porous- and cast-nickel samples. After a longer time of oxidation, a non-adherent duplex NiO scale was formed. The two layers of the duplex scales were different in color. NiO particles were observed in most of the pores of the porous-nickel samples. Finally, the linear oxidation kinetics and the formation of porous non-adherent duplex oxide scales on the inhomogeneous nickel substrates demonstrated that the addition of new layers of NiO occurred at the scale/metal interface due to the thermodynamically possible reaction between Ni and the molecular oxygen migrating inwardly.

  4. Metallurgi for Ingeniører

    DEFF Research Database (Denmark)

    Pedersen, Jan

    Ny gennemarbejdet udgave af den klassiske "Metallurgi for Ingeniører", først skrevet af K. Offer Andersen i 1962......Ny gennemarbejdet udgave af den klassiske "Metallurgi for Ingeniører", først skrevet af K. Offer Andersen i 1962...

  5. Investigation of the powder loading of gas-atomized Ti6Al4V powder using an ‘in-house’ binder for metal injection moulding

    CSIR Research Space (South Africa)

    Seerane, MN

    2013-10-01

    Full Text Available choice for applications such as watch parts, medical devices/implants and dental components, and sports goods. These parts can be made with powder metallurgy processes such as MIM. In MIM the powder loading, i.e. the ratio of the powder to the binder...

  6. The metallurgy, science and engineering

    International Nuclear Information System (INIS)

    Pineau, A.; Quere, Y.

    2011-01-01

    Metallurgy, the science of metals and the technical discipline concerned with the production, shaping and assembling of metals, is one of the major assets of European economy. The French metallurgy industry - from producers (steel, light alloys, ...) to users (car, aviation, nuclear industries, ...) -- has achieved in many of its sectors a world-class level of excellence, based on high-quality research centres that are recognized both for their theoretical and experimental academic work. By contrast, public research is insufficiently concerned with engineering. In 2004, this industry employed 1 800 000 persons, 220 000 of which worked as engineers and managers in 45 000 companies, with a turnover of 420 billion euros. This state of grace is starting to decline. We are undergoing, in this sector as in others, a de-industrialization that affects upstream activities: courses in these disciplines, which have been previously outstanding, have partially disappeared; laboratories have shrunk; expertise has been dispersed; students are staying away from a discipline they consider 'unfruitful', like many other engineering sciences. Simultaneously, further up in this sector, decision centres have moved away from production centres and away from our country. France still maintains a few important R and D centres within international groups in spite of France's decreasing weight in world production. However, these groups see the future of R and D as being centred in the emerging countries (China, India...). The main users (transport, energy, ...) are losing their experts as are the technical centres on which rely a large network of small and medium businesses. The consequences are alarming in view of the already noticeable loss of technical control. This trend can and must be reversed. Because of its presence in many industrial sectors and its excellence, metallurgy - including both research and industry - is an essential activity in which France should remain a major player

  7. Progress report of the Metallurgy Group

    International Nuclear Information System (INIS)

    Sundaram, C.V.; Moorthy, V.K.

    1975-01-01

    The activities of the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay, during the year 1974 are reported under six sections, namely: ore dressing; extractive metallurgy; ceramics; physical metallurgy; corrosion and electrometallurgy, and radiometallurgy. The developmental programme is not only concerned with materials of nuclear interest such as uranium, thorium, plutonium, zirconium, niobium and beryllium, but also other materials of national interest such as titanium, tantalum, ceramics, corrosion-resistant alloys etc. In addition to the laboratory studies, collaborative work has also been undertaken with other units of the Department of Atomic Energy. (A.K.)

  8. Processing of Elemental Titanium by Powder Metallurgy Techniques

    OpenAIRE

    Bolzoni, Leandro; Ruiz Navas, Elisa María; Gordo Odériz, Elena

    2013-01-01

    [Poster] 6th International Light Metals Technology Conference (LMT2013), 24-26 July, Windsord (UK) Titanium is characterised by an outstanding combination of properties like high strength, low density, good corrosion resistance and biocompatibility. Nonetheless, widespread employment of titanium at the industrial level, especially in the automotive industry, has not been achieved yet because of its high extraction and production costs. Consequently, titanium finds applications mainly in hi...

  9. Cold hydrostatic extrusion of powder metallurgy processed superconducting materials

    International Nuclear Information System (INIS)

    Pourrahimi, S.; Thieme, C.L.H.; Foner, S.; Murphy, R.J.

    1983-01-01

    Hydrostatically extruded multifilamentary composites of Cu-Nb, Cu-Nb with a central tin core and Nb-Al were directly drawn to fine wires without intermediate annealing. Uniform deformation was observed throughout the process. Cu-Nb composite wires were Sn plated for external diffusion. Overall critical current densities of better than 10 4 A/cm 2 at 16 T were achieved for Nb 3 Sn-Cu composite wires with nominal areal reductions of 2000

  10. Crack Growth Modeling in an Advanced Powder Metallurgy Alloy

    Science.gov (United States)

    1980-07-01

    Continuo n reve.rse side if necessary and idenifv by black number) Fatigue, Cyclic Crack Growth Rate, Fatigue Crack Propagation, Hold Time, Frequency...complicates life analysis. The purpose of this program was to develop an improved understanding of the crack growth behavior of an advanced turbine disk...it was expected that the effects would be more complex than could be fully deter- mined by this statistical design. Therefore, to improve predictions

  11. The effect of powder metallurgy process parameters on mechanical ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 9 (2011) >. Log in or Register to get access to full text downloads.

  12. Powder metallurgy Rene 95 rotating turbine engine parts, volume 2

    Science.gov (United States)

    Wilbers, L. G.; Redden, T. K.

    1981-01-01

    A Rene 95 alloy as-HIP high pressure turbine aft shaft in the CF6-50 engine and a HIP plus forged Rene 95 compressor disk in the CFM56 engine were tested. The CF6-50 engine test was conducted for 1000 C cycles and the CFM56 test for 2000 C cycles. Post test evaluation and analysis of the CF6-50 shaft and the CFM56 compressor disk included visual, fluorescent penetrant, and dimensional inspections. No defects or otherwise discrepant conditions were found. These parts were judged to have performed satisfactorily.

  13. Dual-Alloy Disks are Formed by Powder Metallurgy

    Science.gov (United States)

    Harf, F. H.; Miner, R. V.; Kortovich, C. S.; Marder, J. M.

    1982-01-01

    High-performance disks have widely varying properties from hub to rim. Dual property disk is fabricated using two nickel-base alloys, AF-115 for rim and Rene 95 for hub. Dual-alloy fabrication may find applications in automobiles, earth-moving equipment, and energy conversion systems as well as aircraft powerplants. There is potential for such applications as shafts, gears, and blades.

  14. High Temperature Degradation of Powder-processed Ni-based Superalloy

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Natália; Pizúrová, Naděžda; Roupcová, Pavla; Dymáček, Petr

    2015-01-01

    Roč. 22, č. 2 (2015), s. 85-94 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : powder materials * polycrystalline Ni-based superalloy * creep machine grips * oxidation Subject RIV: JG - Metallurgy

  15. [Respiratory diseases in metallurgy production workers].

    Science.gov (United States)

    Shliapnikov, D M; Vlasova, E M; Ponomareva, T A

    2012-01-01

    The authors identified features of respiratory diseases in workers of various metallurgy workshops. Cause-effect relationships are defined between occupational risk factors and respiratory diseases, with determining the affection level.

  16. Effect of carbon on mechanical properties of powder-processed Fe ...

    Indian Academy of Sciences (India)

    Keywords. Fe–P alloys; mechanical properties; powder metallurgy; forged; ancient iron. Abstract. The present paper records the results of mechanical tests on iron-phosphorus powder alloys which were made using a hot powder forging technique. ... Densification as high as 98.9% of theoretical density, has been realized.

  17. Effect of carbon on the mechanical properties of powder-processed ...

    Indian Academy of Sciences (India)

    Keywords. Fe–P alloys; mechanical properties; powder metallurgy; forged; ancient iron. Abstract. The present paper records the results of mechanical tests on iron–phosphorus powder alloys which were made using a hot powder forging technique. ... Densification as high as 98·9% of theoretical density; has been realized.

  18. Emerging Applications Using Magnesium Alloy Powders: A Feasibility Study

    Science.gov (United States)

    Tandon, Rajiv; Madan, Deepak

    The use of powder metallurgy offers a potential processing route based on tailored compositions and unique microstructures to achieve high performance in magnesium alloys. This paper highlights recent advances in the production, qualification, and characterization of gas atomized AZ91E, WE43 and Elektron21 alloy powders. Transmission electron microscopy (TEM) was used to understand the bulk and surface structure of the atomized powder. The potential for using these magnesium alloy powders for emerging applications involves establishing compatibility with viable consolidation processes such as cold spray, laser assisted deposition, forging and extrusion. This study summarizes the preliminary results for various ongoing investigations using WE43 powder as an example. Results show that powder metallurgy processed WE43 results in comparable properties to those obtained from cast and wrought and offers potential for improvement.

  19. Current programmes on physical metallurgy and related areas in BARC

    International Nuclear Information System (INIS)

    1994-01-01

    Current research and development programmes on physical metallurgy and related areas from the following Divisions of Bhabha Atomic Research Centre are included in this report : Atomic Fuels Division, High Pressure Physics Division, Metallurgy Division, Radio Metallurgy Division, Solid State Physics Division. Important publications corresponding to each activity have also been listed. (author)

  20. Ideate about building green mine of uranium mining and metallurgy

    International Nuclear Information System (INIS)

    Shi Zuyuan

    2012-01-01

    Analysing the current situation of uranium mining and metallurgy; Setting up goals for green uranium mining and metallurgy, its fundamental conditions, Contents and measures. Putting forward an idea to combine green uranium mining and metallurgy with the state target for green mining, and keeping its own characteristics. (author)

  1. Biennial activity report of metallurgy programme for 1987 and 1988

    International Nuclear Information System (INIS)

    Shanmugam, V.; Rao, B.P.C.; Bhanu Sankara Rao, K.; Muralidharan, P.; Bhaduri, A.K.; Kuppusami, P.; Shyamsunder, M.T.; Sampath, N.; Sreedharan, O.M.

    1990-01-01

    The research and development (R and D) activities in the field of metallurgy at Indira Gandhi Centre for Atomic Research, Kalpakkam during 1987-1988 are reported in the form of individual summaries arranged under headings : (1) Mechanical Metallurgy Section, (2) Physical Metallurgy Section, (3) Chemical Metallurgy Section, (4) Materials Technology Section, (5) Division for PIE and NDT Development and (6) Quality Engineering Section. A list of publications by the staff scientists working in the field of metallurgy during report period is given in one of the appendices. (author). figs., tabs

  2. Titanium Powder Sintering in a Graphite Furnace and Mechanical Properties of Sintered Parts

    OpenAIRE

    Changzhou Yu; Peng Cao; Mark Ian Jones

    2017-01-01

    Recent accreditation of titanium powder products for commercial aircraft applications marks a milestone in titanium powder metallurgy. Currently, powder metallurgical titanium production primarily relies on vacuum sintering. This work reported on the feasibility of powder sintering in a non-vacuum furnace and the tensile properties of the as-sintered Ti. Specifically, we investigated atmospheric sintering of commercially pure (C.P.) titanium in a graphite furnace backfilled with argon and stu...

  3. Metallurgy department publications and lectures 1987

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

    1988-04-01

    A presentation (including abstract) of scientific and technical publications and lectures by the staff of the Metallurgy Department during 1987 is given. The list comprises journal papers, conference papers, reports, lectures and poster presentations in the following categories: Publications, Lectures and Poster Presentations. (author)

  4. Investigations to problems of the implantation metallurgy

    International Nuclear Information System (INIS)

    Rauschenbach, B.

    1987-01-01

    Basing on processes and effects caused ion implantation of metals a review is given about the problems of the implantation metallurgy. Techniques of high-fluence ion implantation and ion beam mixing are generally confined. These techniques change the structure and the chemical composition in the near of the surface of metals. The application of these methods is demonstrated on series of examples. (author)

  5. Development and prospect of china uranium mining and metallurgy

    International Nuclear Information System (INIS)

    Que Weimin; Wang Haifeng; Niu Yuqing; Gu Wancheng; Zhang Feifeng

    2007-01-01

    The development of industry of uranium mining and metallurgy in China has been reviewed generally, emphasizing on investigation approaches and application levels of uranium mining technologies such as in-situ leaching, heap leaching, stope leaching: on the basis of analysis on status of uranium mining and metallurgy and problems existed, also considering the specific features of deposit resources, the development orientation of uranium mining and metallurgy in China is pointed out. The industry of China uranium mining and metallurgy is faced to new opportunity of development and challenge in 21st century, the only way to realize sustainable development of uranium mining and metallurgy and harmonious development between economy and environment is to develop new technology on mining, ore beneficiation and metallurgy, increase the utilization level of uranium resources, low down impact on environment caused by mining and metallurgy. (authors)

  6. Comparison of conventional and High Velocity Compaction of alumina powders

    OpenAIRE

    Souriou , David; Goeuriot , Patrice; Bonnefoy , Olivier; Thomas , Gérard; Drapier , Sylvain; Bourdin , Stéphane; Lazzarotto , Ludovic

    2006-01-01

    International audience; Ceramic compacts can be usually prepared by uniaxial pressing in a die made of stainless steel, but the pressure applied is limited and density gradients occur in many cases. Recently a new forming method in powder metallurgy, the High Velocity Compaction (HVC) has been applied to ceramic powders. This method is similar to conventional pressing but consists in making an ram falling down at a very high speed to the upper punch. The kinetic energy is converted into a str...

  7. Computational thermodynamics in electric current metallurgy

    DEFF Research Database (Denmark)

    Bhowmik, Arghya; Qin, R.S.

    2015-01-01

    A priori derivation for the extra free energy caused by the passing electric current in metal is presented. The analytical expression and its discrete format in support of the numerical calculation of thermodynamics in electric current metallurgy have been developed. This enables the calculation...... of electric current distribution, current induced temperature distribution and free energy sequence of various phase transitions in multiphase materials. The work is particularly suitable for the study of magnetic materials that contain various magnetic phases. The latter has not been considered in literature....... The method has been validated against the analytical solution of current distribution and experimental observation of microstructure evolution. It provides a basis for the design, prediction and implementation of the electric current metallurgy. The applicability of the theory is discussed in the derivations....

  8. Metallurgy Department. Annual progress report for 1989

    International Nuclear Information System (INIS)

    Horsewell, A.; Hansen, N.

    1990-07-01

    Selected activities of the Metallurgy Department at Risoe National Laboratory during 1989 are described. The work is presented in three chapters: Materials Science, Materials Engineering and Materials Technology. A survey is given of the Department's participation in international collaboration and of its acitivities within eduation and training. Furthermore, the main figures outlining the funding and expenditure of the Department are given. Lists of staff members, visiting scientists, publicaltions, lectures and poster presentations are included. (author) 90 refs

  9. Metallurgy Department annual progress report for 1987

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.; Hansen, N.

    1988-05-01

    Selected activities of the Metallurgy Department at Risoe National Laboratory during 1987 are described. The work is presented in four chapters: Materials Science, Materials Engineering, Materials Technology and Energy Programmes. A survey is given of the Department's participation in international collaboration and of its activities within education and training. Furthermore, the main numbers illustrating the Departments's economy are given. Lists of staff members, visiting scientists, publications, lectures and poster presentations are included. 38 ills. (author)

  10. Metallurgy Department. Annual progress report for 1988

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.; Hansen, N.

    1989-05-01

    Selected activities of the Metallurgy Department at Risoe National Laboratory during 1988 are described. The work is presented in four chapters: Materials Science, Materials Engineering, Materials Technology and Energy Programmes. A survey is given of the Department's participation in international collaboration and of its activities within education and training. Furthermore, the main numbers illustrating the Department's economy are given. Lists of staff members, visiting scientists, publications, lectures and poster presentations are included. (author) 36 ills., 81 refs

  11. Review of the Methods for Production of Spherical Ti and Ti Alloy Powder

    Science.gov (United States)

    Sun, Pei; Fang, Zhigang Zak; Zhang, Ying; Xia, Yang

    2017-10-01

    Spherical titanium alloy powder is an important raw material for near-net-shape fabrication via a powder metallurgy (PM) manufacturing route, as well as feedstock for powder injection molding, and additive manufacturing (AM). Nevertheless, the cost of Ti powder including spherical Ti alloy has been a major hurdle that prevented PM Ti from being adopted for a wide range of applications. Especially with the increasing importance of powder-bed based AM technologies, the demand for spherical Ti powder has brought renewed attention on properties and cost, as well as on powder-producing processes. The performance of Ti components manufactured from powder has a strong dependence on the quality of powder, and it is therefore crucial to understand the properties and production methods of powder. This article aims to provide a cursory review of the basic techniques of commercial and emerging methods for making spherical Ti powder. The advantages as well as limitations of different methods are discussed.

  12. Production of Al-Si-Fe-Xalloys by Powder Mettalurgy

    Czech Academy of Sciences Publication Activity Database

    Školáková, A.; Novák, P.; Vojtěch, D.; Kubatík, Tomáš František

    2014-01-01

    Roč. 14, č. 3 (2014), s. 437-441 ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] Institutional support: RVO:61389021 Keywords : Aluminium alloys * powder metallurgy * NiTi * mechanical alloying * reactive sintering Subject RIV: JG - Metallurgy http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

  13. Metallurgy and Heat Treating. Welding Module 7. Instructor's Guide.

    Science.gov (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching a three-unit module in metallurgy and heat treating. The module is part of a welding curriculum that has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The basic principles of metallurgy and heat treatment and techniques for…

  14. New radiation technologies and methods for control of technological processes in metallurgy

    International Nuclear Information System (INIS)

    Zaykin, Yu.

    1996-01-01

    Radiation Technology of Metal and Ceramic Production with Enhanced Service Properties. Based on application of radiation technique in powder metallurgy the new technology for obtaining metals, alloys and ceramic materials with high service properties is worked out. Radiation processing of powder materials at the certain stage of the process leads to profound structure alterations at all further stages and eventually effects the properties of the resulting product. Theoretical calculation and experimental studies of electron-positron annihilation in powder-pressed samples showed that irradiation caused powder particles surface state changes favorable for further sintering and crystallization processes development. It is shown that irradiation of metal powders and powder-pressed samples by high energy electrons is technologically most efficient. The right choice of the type-and the mode of the radiation processing makes it possible to obtain metals, alloys and ceramic materials (Mo,Fe, W, Al, Ni, Cu, stainless steels, ceramics, etc.) with homogeneous structure and stable enhanced service properties. The project on radiation technology application to powder metallurgy represented by a group of authors was awarded with the diploma and the gold medal at the 22 International Exhibition of Inventions (Geneva, 1994). New Technologic Opportunities of the Chromium-Nickel Alloys Processing To obtain the required phase-structure state special methods of the chromium-nickel alloy processing for sensitive elastic devices production were worked out combining plastic deformation, thermal and radiation processing. It is shown that h-gbb phase transfer not observed before is possible in extremely non-equilibrium conditions under electron irradiation. It is established that the complex reaction of recrystallization and gb-phase deposition proceeds under electron irradiation at the room temperature when the certain threshold plastic deformation degree is reached that leads to the same

  15. Promoting energy conservation in China's metallurgy industry

    International Nuclear Information System (INIS)

    Lin, Boqiang; Du, Zhili

    2017-01-01

    China is undergoing rapid industrialization and urbanization, with consequent dramatic increase in energy demand. Given energy scarcity, environmental pollution, energy security and energy cost constraints, energy conservation will be the major strategy in China's transition to a low-carbon economy. Since the metallurgy industry is a main sector of energy consumption, the efficiency of energy conservation in this industry will affect the future prospects of energy savings. This paper analyzes the energy conservation potential of China's metallurgy industry. First, seemingly unrelated regression method is applied to investigate the relationship between energy relative price, R&D input, enterprise ownership structure, enterprise scale and energy intensity of the metallurgy industry. Then, based on the SUR results, we use the scenario analysis method to predict energy consumption and savings potential in the industry in different scenarios. This paper provides references for China's government and metallurgy industry in formulating relevant energy conservation policies. - Highlights: • Seemingly unrelated regression method is applied to analyze the energy intensity of metallurgy industry. • We use the scenario analysis method to predict energy consuming and energy saving of Chinese metallurgy industry. • Provide references for China's government and metallurgy industry in formulating relevant energy conservation policies.

  16. Sinterable powders

    International Nuclear Information System (INIS)

    Zanghi, J.S.; Kasprzyk, M.R.

    1979-01-01

    A description is given of sinterable powders and methods of producing sintered products using such powders. The powders consist of (a) a particulate ceramic material, e.g. SiC, having specified particle size and surface area; (b) a carbon source material, e.g. sugar or a phenol-formaldehyde resin; and (c) a residue from a solution of H 3 BO 3 , B 2 O 3 , or mixtures of these as sintering aid. (U.K.)

  17. Biennial activity report of Metallurgy Division for 1989 and 1990

    International Nuclear Information System (INIS)

    Kamachi Mudali, U.; Muraleedharan, P.; Parameswaran, P.; Swaminathan, K.; Sreedharan, O.M.

    1993-01-01

    This is the first divisional biennial report of the Metallurgy Division of Indira Gandhi Centre for Atomic Research, for the year 1989-1990, after formation of the Metallurgy Division in September 1988. Major areas of work in the Division relate to aqueous corrosion and localised corrosion, stress corrosion cracking and liquid metal corrosion, high temperature oxidation, thermodynamic studies, physical metallurgy studies for structure-property correlations and failure analyses. The principal materials of studies have been the austenitic stainless steels, the current materials of construction in the Fast Breeder Test Reactor and the candidate materials for the Prototype Fast Breeder Reactor

  18. Chemistry and metallurgy in the Portuguese Empire

    Energy Technology Data Exchange (ETDEWEB)

    Habashi, F. [Laval Univ., Sainte-Foy, Quebec City, PQ (Canada)

    2000-10-01

    The foundation and expansion of the Portuguese Empire is sketched, with emphasis on the development of a new type of ship by Prince Henrique the Navigator (AD 1385-1460), known as the caravel. By virtue of its advanced design, it was capable of sailing the stormy seas at high speeds, and thereby was instrumental in extending Portuguese influence over vast territories in South America, Asia and Africa, extending Portuguese know-how in mining, metallurgy, chemistry and trade along with Christianity. The role played by the University of Coimbra, founded in 1306, and the contribution of the Brazilian Geological Survey, established in 1875, and of the School of Mines in Ouro Preto in Brazil in 1876, in the exploitation of the mineral wealth of the Portuguese colonies is chronicled.

  19. (YSZ) powders

    Indian Academy of Sciences (India)

    Unknown

    Keywords. YSZ powder; dispersion behaviour; grindability. 1. Introduction. During the synthesis of oxide powders by solution based techniques (e.g. solution combustion, decomposition of metal nitrates, precipitation etc), agglomerates of fine crystallites of the precursors or oxides form and their size vary up to many microns.

  20. Thermogravimetric control of intermediate compounds in uranium metallurgy

    International Nuclear Information System (INIS)

    Gasco Sanchez, L.; Fernandez Cellini, R.

    1959-01-01

    The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs

  1. Powder metallurgical high performance materials. Proceedings. Volume 3: general topics

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

  2. Effect of carbon on mechanical properties of powder-processed Fe ...

    Indian Academy of Sciences (India)

    Administrator

    Alloys developed in the present investigation were capable of hot working to very thin gauge of sheets and wires. Keywords. Fe–P alloys; mechanical properties; powder metallurgy; forged; ancient iron. 1. Introduction. Archeological iron is often seen to contain levels of phosphorus which are much higher than those found in.

  3. Effect of chromium on the corrosion behaviour of powder-processed ...

    Indian Academy of Sciences (India)

    The studies compare electrolytic Armco iron with Fe–P alloys. It was observed that, chromium improved the resistance to corrosion in acidic and marine environments. The corrosion rates were minimal in alkaline medium and low in neutral solution. Keywords. Iron-phosphorous alloys; corrosion; powder metallurgy; forged;.

  4. Compacting the powder of Al-Cr-Mn Alloy with SPS

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Pala, Zdeněk; Novák, P.

    2015-01-01

    Roč. 49, č. 1 (2015), s. 129-132 ISSN 1580-2949 Institutional support: RVO:61389021 Keywords : aluminium alloy * intermetallics * powder metalurgy * spark-plasma sintering Subject RIV: JG - Metallurgy Impact factor: 0.439, year: 2015 http://mit.imt.si/Revija/izvodi/mit151/kubatik.pdf

  5. Investigation into the production of metastable Nb3Ge powder via the rotating electrode process

    International Nuclear Information System (INIS)

    McCormick, J.P.

    1977-12-01

    The production of metastable Nb 3 Ge powder via the rotating electrode process (REP) employing ''splat cooling'' was investigated. An electrode capable of withstanding the thermal shock of the electric arc used in REP was produced through powder metallurgy techniques. The effect of various parameters involved in the rotating electrode process was studied in correlation with process control and crystal structure, microstructure and compositional analyses of the powder produced. Superconducting transition temperature measurements were made on the powder both as-produced and after annealing experiments

  6. The metallurgy of superalloys part 2

    International Nuclear Information System (INIS)

    Abdelazim, M.E.; Hammad, F.H.

    1990-01-01

    This is part II of the report titled 'the metallurgy of superalloys'. It deals with the effect of heat treatment and operating conditions (thermal exposure and environment) on the mechanical properties of superalloys. The heat treatment is important in the development of superalloys through that it controls type, amount, size shape and distribution of the precipitate and the grain size of the matrix. The thermal exposure leads to reduction in the amount of the primary carbides and to precipitation of secondary carbides. Also it leads to the agglomeration and coarsening of gamma or the transformation of gamma phase to phase. The environment may lead to the internal oxidation, carburization, decarburization or sulphidization of the superalloys which may result in the degradation of their mechanical properties. This part gives also an example of applications of superalloys in the field of nuclear reactors especially high temperature-gas cooled reactors. Joined with this part a table which contains the major superalloys including its chemical analysis, creep rupture strength and some of its applications. 1 tab

  7. 78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...

    Science.gov (United States)

    2013-02-05

    ... Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels will hold a meeting on...

  8. The Metallurgy of some indian swords

    Directory of Open Access Journals (Sweden)

    Williams, Alan

    2007-12-01

    Full Text Available The metallurgy of Indian swords shows many differences from that of European swords. The distinction between "Damascus Steel" (or wootz and crucible steel is explained. Ten broken blades from the Armoury of the Nizams of Hyderabad were made available for microscopic examination. Six of these seem to been made from crucible steels, and are of notably high quality. By contrast, a group of six randomly collected from Private Collections in England were also examined. Only one of these was made of crucible steel, and three of the others were of very mediocre quality. This perhaps represents the quality of blades available to the average Indian soldier.

    La metalurgia de las espadas indias presenta notables diferencias en comparación con la de las europeas. Se explica la distinción entre el ‘acero de Damasco’ (o wootz y el acero de crisol. Se ha realizado un análisis microscópico de un conjunto de diez hojas rotas de espada depositadas en la Armería de los Nizams de Hyderabad. Seis de ellas parecen haber sido realizadas a partir de acero de crisol, y son de elevada calidad. En contraste, se examinó también un grupo de seis espadas de colecciones privadas en Inglaterra. Sólo una de ellas estaba fabricada con acero de crisol, y tres de las otras eran de calidad muy mediocre. Esto representa quizá la calidad de las hojas de espada al alcance del soldado medio indio.

  9. Biennial activity report of Metallurgy Programme - 1985 and 1986

    International Nuclear Information System (INIS)

    Mallika, C.; Sreenivasan, P.R.; Muraleedharan, P.; Shyamsunder, M.T.; Kuppuswami, P.; Sampath, N.; Bhaduri, A.K.; Sreedharan, O.M.

    1988-01-01

    The biennial activity report of the Metallurgy Programme of the Indira Gandhi Centre for Atomic Research covers the period of the years 1985 and 1986. Along with NDT, welding metallurgy, low cycle fatigue, creep and creep fatigue interactions, structure-property correlations, thermodynamics and corrosion metallurgy of alloy steels with respect to their compatibility with aqueous and liquid sodium environments continue to be the major thrust areas of the Programme. Some of the basic research contributions of the Programme are: the observation of uniform and homogeneous distribution of voids in cyclically deformed 304 SS, the role of grain boundaries and precipitation in dynamic strain ageing of 316 SS and the determination of the activities of component metals in 316 and 304 SS by metastable EMF method. (author)

  10. Powder Diffraction

    Science.gov (United States)

    Hart, Michael

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer1,2 in Germany and, quite independently, by Hull3,4 in the United States of America. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the, first period, until the- mid-1940's. applications were and developed covering broad categories of materials including inorganic materials, minerals, cerarffics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated5. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish6 and by Langford and Loudr7. By 1980 there were probably 10000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation8-10. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments11.

  11. Powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M.

    1995-12-31

    the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940`s, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments.

  12. Powder diffraction

    International Nuclear Information System (INIS)

    Hart, M.

    1995-01-01

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940's, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments

  13. Summarizing of new techniques in uranium mining and metallurgy

    International Nuclear Information System (INIS)

    Wang Delin; Zhang Fei; Su Yanru; Zeng Yijun; Meng Jin

    2010-01-01

    According to character of national resources and uranium mining and metallurgical science and technology members research achievements, new techniques in ten scientific research area of in-situ leaching, heap leaching, multi-metal comprehensive recovery, bio-metallurgy etc. for 10 years is introduced in this paper. The level of innovation ability is shown by technical index, resources recovery and reduction capital cost etc. datum. The application bound of natural uranium resource is enlarged and production ability of national uranium is increased. It is put forward renovation and development ideas for uranium mining and metallurgy. (authors)

  14. Effect of Carbon Content on the Properties of Iron-Based Powder Metallurgical Parts Produced by the Surface Rolling Process

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2018-01-01

    Full Text Available In recent years, the rolling densification process has become increasingly widely used to strengthen powder metallurgy parts. The original composition of the rolled powder metallurgy blank has a significant effect on the rolling densification technology. The present work investigated the effects of different carbon contents (0 wt. %, 0.2 wt. %, 0.45 wt. %, and 0.8 wt. % on the rolling densification. The selection of the raw materials in the surface rolling densification process was analyzed based on the pore condition, structure, hardness, and friction performance of the materials. The results show that the 0.8 wt. % carbon content of the surface rolling material can effectively improve the properties of iron-based powder metallurgy parts. The samples with 0.8 wt. % carbon have the highest surface hardness (340 HV0.1 and the lowest surface friction coefficient (0.35. Even if the dense layer depth is 1.13 mm, which is thinner than other samples with low carbon content, it also meets the requirements for powder metallurgy parts such as gears used in the auto industry.

  15. Microstructure, mechanical and corrosion properties of biodegradable powder metallourgical Fe-2 wt% X (X = Pd, Ag and C) alloys

    Czech Academy of Sciences Publication Activity Database

    Čapek, Jaroslav; Stehlíková, K.; Michalcová, A.; Msallamová, Š.; Vojtěch, J.

    2016-01-01

    Roč. 181, Sep (2016), 501–511 ISSN 0254-0584 R&D Projects: GA ČR GBP108/12/G043 Institutional support: RVO:68378271 Keywords : biomaterials * powder metallurgy * alloys * electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.084, year: 2016

  16. PROSPECTS OF MANUFACTURE OF PISTON RINGS INTERNAL COMBUSTION ENGINES OF POWDER MATERIALS ON THE BASE OF IRON

    Directory of Open Access Journals (Sweden)

    B. M. Musaibov

    2013-01-01

    Full Text Available Development and production of piston rings made of sintered materials on the basis of iron powder metallurgy is an innovative way. In the application of this technology reduces the consumption of material and costs for the production of piston rings 30-40% in comparison with the traditional methods of their manufacture

  17. Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document

    International Nuclear Information System (INIS)

    Bargelski, C. J.; Berrett, D. E.

    1998-01-01

    The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables

  18. Iron Metallurgy: Technical Terminology Bulletin. Terminotech, Vol. 2, No. 7.

    Science.gov (United States)

    General Electric Co. of Canada, Ltd., Montreal, Quebec.

    This issue of a bulletin of technological terminology is devoted to iron metallurgy. Various aspects of iron production are described in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

  19. Effects of Process Parameters on Copper Powder Compaction Process Using Multi-Particle Finite Element Method

    Science.gov (United States)

    Güner, F.; Sofuoğlu, H.

    2018-01-01

    Powder metallurgy (PM) has been widely used in several industries; especially automotive and aerospace industries and powder metallurgy products grow up every year. The mechanical properties of the final product that is obtained by cold compaction and sintering in powder metallurgy are closely related to the final relative density of the process. The distribution of the relative density in the die is affected by parameters such as compaction velocity, friction coefficient and temperature. Moreover, most of the numerical studies utilizing finite element approaches treat the examined environment as a continuous media with uniformly homogeneous porosity whereas Multi-Particle Finite Element Method (MPFEM) treats every particles as an individual body. In MPFEM, each of the particles can be defined as an elastic- plastic deformable body, so the interactions of the particles with each other and the die wall can be investigated. In this study, each particle was modelled and analyzed as individual deformable body with 3D tetrahedral elements by using MPFEM approach. This study, therefore, was performed to investigate the effects of different temperatures and compaction velocities on stress distribution and deformations of copper powders of 200 µm-diameter in compaction process. Furthermore, 3-D MPFEM model utilized von Mises material model and constant coefficient of friction of μ=0.05. In addition to MPFEM approach, continuum modelling approach was also performed for comparison purposes.

  20. Evaluation of microstructure and phase relations in a powder processed Ti-44Al-12Nb alloy

    International Nuclear Information System (INIS)

    Kumar, S.G.; Reddy, R.G.; Wu, J.; Holthus, J.

    1995-01-01

    Titanium aluminides based on the ordered face-centered tetragonal γTiAl phase possess attractive properties, such as low density, high melting point, good elevated temperature strength, modulus retention, and oxidation resistance, making these alloys potential high-temperature structural materials. These alloys can be processed by both ingot metallurgy and powder metallurgy routes. In the present study, three variations of the powder metallurgy route were studied to process a Ti-44Al-12Nb (at.%) alloy: (a) cold pressing followed by reaction sintering (CP process); (b) cold pressing, vacuum hot pressing, and then sintering (HP process); and (c) arc melting, hydride-dehydride process to make the alloy powder, cold isostatic pressing, and then sintering (AM process). Microstructural and phase relations were studied by x-ray diffraction (XRD) analysis, optical microscopy, scanning electron microscopy with an energy-dispersive spectrometer (SEM-EDS), and electron probe microanalysis (EPMA). The phases identified were Ti 3 Al and TiAl; an additional Nb 2 Al phase was observed in the HP sample. The microstructures of CP and HP processed samples are porous and chemically inhomogeneous whereas the AM processed sample revealed fine equiaxed microstructure. This refinement of the microstructure is attributed to the fine, homogeneous powder produced by the hydride-dehydride process and the high compaction pressures

  1. Fabrication of nuclear fuel by powder injection moulding: Study of the binders systems and the de-binding of feedstock containing actinide powder

    International Nuclear Information System (INIS)

    Bricout, J.

    2012-01-01

    Powder Injection Moulding (PIM) is identified as an innovative process for the nuclear fuel fabrication. Technological breakthrough compared to the current process of powder metallurgy, the impact of actinide powder's specificities on the different steps of PIM is performed. Alumina powders simulating actinide powder have been implemented with a reference binders system. Thermal and rheological studies show the injectability and the de-binding of feedstocks with adequate solid loading (≥50 %vol), thanks to the de-agglomeration during the mixing step, which allow to obtain net shape fuel pellet. Specific surface area of powders, acting as a key role in behaviour's feedstocks, has been integrated in analysis models of viscosity prediction according to the shear rate. Also conducted studies on uranium oxide powder show that the selected binders systems, which have a compatible rheological behaviour with PIM process, impact the de-agglomeration of powder and final microstructure of the fuel pellet, consistent with the results obtained on alumina powders. Independent behaviour of binders and uranium oxide powder, showing no adverse chemical reaction against the PIM process, show a residual mass of carbon of about 150 ppm after sintering. Binders system using polystyrene, resistant to radiolysis phenomena and loadable more than 50 %(vol) of actinide powder, shows the promising potential of PIM process for the fuel fabrication. (author) [fr

  2. On modeling the CNC end milling characteristics of Al-7075/WC powder metallurgy composites

    Science.gov (United States)

    Hanuman, N. S. V. N.; Rao, P. Gangadhara; Kumar, B. Sudheer; Karthik, N.

    2017-07-01

    Surface finish and material removal rate are two important factors in the manufacturing which affect acceptability of the product which in turn reflects on the profitability of the organization. The worth of the production setup to produce the components with high material removal rate (MRR) without sacrificing the surface requirements can play vital role in sustainability and profitability of the organization. In this paper, the effect of process parameters on metal removal rate and surface roughness has been investigated in milling of Al7075-MMC with WC as reinforcement element. Cutting speed, feed and depth of cut have been taken as input factors in three level response surface methodologies used for experimentation. Mathematical models have been developed using response surface methodology to predict surface finish, and metal removal rate in term of machining parameters. Depth of cut and feed rate are found to be a dominant parameter for surface roughness; whereas feed rate mainly affects the metal removal rate. The results of mathematical models have been compared with the experimental and found to be in good agreement. The results of predicted model can be used in selection of process parameters to insure desired quality and improved productivity.

  3. Cost-Effective Powder Metallurgy TiAl-Based Components For Aerospace Use Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Gamma titanium aluminide (TiAl) alloys with their low density (~3.9g/cm3), good elevated temperature strength, stiffness, creep resistance and acceptable burn and...

  4. Neutron diffraction measurements of residual stress in a powder metallurgy component

    International Nuclear Information System (INIS)

    Schneider, L.C.R.; Hainsworth, S.V.; Cocks, A.C.F.; Fitzpatrick, M.E.

    2005-01-01

    Residual stresses in a typical industrial green component were determined using neutron diffraction. The measured residual stresses were found to correlate with cross-sectional variations. Residual stress at the edge of the compact in contact with the die wall during compaction reached up to +80 MPa (tension) and -100 MPa (compression)

  5. Effect of the Machining Processes on Low Cycle Fatigue Behavior of a Powder Metallurgy Disk

    Science.gov (United States)

    Telesman, J.; Kantzos, P.; Gabb, T. P.; Ghosn, L. J.

    2010-01-01

    A study has been performed to investigate the effect of various machining processes on fatigue life of configured low cycle fatigue specimens machined out of a NASA developed LSHR P/M nickel based disk alloy. Two types of configured specimen geometries were employed in the study. To evaluate a broach machining processes a double notch geometry was used with both notches machined using broach tooling. EDM machined notched specimens of the same configuration were tested for comparison purposes. Honing finishing process was evaluated by using a center hole specimen geometry. Comparison testing was again done using EDM machined specimens of the same geometry. The effect of these machining processes on the resulting surface roughness, residual stress distribution and microstructural damage were characterized and used in attempt to explain the low cycle fatigue results.

  6. Powder metallurgy routes toward aluminum boron nitride nanotube composites, their morphologies, structures and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Maho [Nanotube Unit, World Premier International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 3050044 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1, Tsukuba, Ibaraki 3050005 (Japan); Meng, Fanqiang [Research Center for Strategic Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 3050044 (Japan); Firestein, Konstantin [Laboratory of Inorganic Nanomaterials, National University of Science and Technology “MISIS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); Tsuchiya, Koichi [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1, Tsukuba, Ibaraki 3050005 (Japan); Research Center for Strategic Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 3050044 (Japan); Golberg, Dmitri, E-mail: GOLBERG.Dmitri@nims.go.jp [Nanotube Unit, World Premier International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 3050044 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1, Tsukuba, Ibaraki 3050005 (Japan)

    2014-05-01

    Aluminum/boron nitride nanotube (BNNT) composites with up to 5 wt% (i.e., 9.7 vol%) nanotube fractions were prepared via spark plasma sintering (SPS) and high-pressure torsion (HPT) methods. Various microscopy techniques, X-ray diffraction, and energy dispersive X-ray analysis confirmed the integration of the two phases into decently dense and compact composites. No other phases, like Al borides or nitrides, formed in the Al–BNNTs macrocomposites of the two series. The BNNTs were found to be preferentially located along Al grain boundaries in SPS samples (grain size was 10–20 μm) creating micro-discontinuities and pores which were found to be detrimental for the sample hardness, whereas in HPT samples, the tubes were rather evenly distributed within a fine-grained Al matrix (grain size of several hundred nm). Therefore, the hardness of HPT samples was drastically increased with increasing BNNTs content in Al pellets. The value for Al–BNNT 3.0 wt% sample was more than doubled (190 MPa) compared to a pure Al–HPT compact (90 MPa). And the room temperature ultimate tensile strength of Al–BNNTs HPT samples containing 3.0 wt% BNNT (∼300 MPa) became ∼1.5 times larger than that of a BNNT-free HPT–Al compact (∼200 MPa)

  7. Al and Mg Alloys for Aerospace Applications Using Rapid Solidification and Powder Metallurgy Processing

    Science.gov (United States)

    1989-03-28

    position of the Mg2Si liquidus, then a slight change in the eutectic composition is expected, and has been estimated to be = 1%Si. If, on the other hand ...the 10 wt.% Gd alloys were excellent. The alloys retained on average 91% of their room temperature yield and ultimate strenght at 200"C. The ductility...the other hand , results from the introduction of the same shear displacement on every second (001) plane. The resulting tetragonal unit cells have a c/a

  8. Cost-Effective Powder Metallurgy TiAl-Based Components For Aerospace Use, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Gamma titanium aluminide (TiAl) alloys with their low density (~3.9g/cm3), good elevated temperature strength, stiffness, creep resistance and acceptable burn and...

  9. Cu-TiB metal matrix composites prepared by powder metallurgy route

    Directory of Open Access Journals (Sweden)

    Guo Z.

    2015-01-01

    Full Text Available Titanium boride (TiB is characterized by good conductivity, high strength and high melting point. In this work, TiB was used to make Cu-TiB metal matrix composites (MMCs. Amounts of TiB added into Cu matrix were 2wt.%, 5wt.%, 10 wt.% and 15 wt.%. The samples were pressed at pressures of 500MPa, 600MPa, 700MPa and 800MPa and sintered at 820o and 920o, respectively. The properties of the sintered composites such as hardness and impact toughness were studied. Hardness and impact toughness of samples increased with increasing pressures and decreased with increasing contents of TiB. Composite with good mechanical properties and high conductivity was obtained from the sample containing 2wt.%TiB compacted at 800MPa and sintered at 920o. It was shown that 2wt.% TiB is a suitable content to make Cu-TiB MMCs with good mechanical properties and excellent conductivity.

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

    Science.gov (United States)

    Ray, Ranjan; Jha, Sunil C.

    1987-01-01

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

  11. Utilization of Space Shuttle External Tank materials by melting and powder metallurgy

    Science.gov (United States)

    Chern, T. S.

    1985-01-01

    The Crucible Melt Extraction Process was demonstrated to convert scraps of aluminum alloy 2219, used in the Space Shuttle External Tank, into fibers. The cast fibers were then consolidated by cold welding. The X-ray diffraction test of the cast fibers was done to examine the crystallinity and oxide content of the fibers. The compressive stress-strain behavior of the consolidated materials was also examined. Two conceptual schemes which would adapt the as-developed Crucible Melt Extraction Process to the microgravity condition in space were finally proposed.

  12. Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

    Science.gov (United States)

    Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

    2014-10-01

    New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Precipitation in Powder Metallurgy, Nickel Base Superalloys: Review of Modeling Approach and Formulation of Engineering (Postprint)

    Science.gov (United States)

    2016-12-01

    96VMDσ ; ð3Þ in which R is the gas constant, and VM is the molar volume of the precipitate. Strictly speaking, Eqs. (1)–(3) apply to nucleation in two...the results in Fig. 5. The molar volume VM was calculated to be 7.20 × 10−6, 7.11 × 10−6, and 7.22 × 10−6 m3/mol for IN-100, René 88, and LSHR, re...constant T, absolute temperature Tγ′, γ′ solvus temperature t, time VM, molar volume v, activity coefficient Semiatin et al. Integrating Materials and

  14. Uranium 2000 : International symposium on the process metallurgy of uranium

    International Nuclear Information System (INIS)

    Ozberk, E.; Oliver, A.J.

    2000-01-01

    The International Symposium on the Process Metallurgy of Uranium has been organized as the thirtieth annual meeting of the Hydrometallurgy Section of the Metallurgical Society of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM). This meeting is jointly organized with the Canadian Mineral Processors Division of CIM. The proceedings are a collection of papers from fifteen countries covering the latest research, development, industrial practices and regulatory issues in uranium processing, providing a concise description of the state of this industry. Topics include: uranium industry overview; current milling operations; in-situ uranium mines and processing plants; uranium recovery and further processing; uranium leaching; uranium operations effluent water treatment; tailings disposal, water treatment and decommissioning; mine decommissioning; and international regulations and decommissioning. (author)

  15. Effect of nickel addition on mechanical properties of powder forged Fe-Cu-C

    Science.gov (United States)

    Archana Barla, Nikki

    2018-03-01

    Fe-Cu-C system is very popular in P/M industry for its good compressibility and dimensional stability with high strength. Fe-Cu-C is a structural material and is used where high strength with high hardness is required. The composition of powder metallurgy steel plays a vital role in the microstructure and physical properties of the sintered component. Fe-2Cu-0.7C-Ni alloy with varying nickel composition (0%, 0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) wt. % was prepared by powder metallurgy (P/M) sinter forging process. The present work discuss the effect of varying nickel content on microstructure and mechanical properties.

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

    Science.gov (United States)

    Gilman, P. S.

    1984-01-01

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

  17. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy.

    Science.gov (United States)

    Ferreira, Sonia C; Conde, Ana; Arenas, María A; Rocha, Luis A; Velhinho, Alexandre

    2014-12-19

    Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiC np ) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiC np on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiC np . The current peaks and the steady-state current density recorded at each voltage step increases with the SiC np volume fraction due to the oxidation of the SiC np . The formation mechanism of the anodic film on Al/SiC np composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiC np in the anodic film.

  18. On a discrepancy in modulus of elasticity as determined from separate resonance frequencies of a bar sintered from copper-coated iron powder

    Czech Academy of Sciences Publication Activity Database

    Kupková, M.; Kupka, M.; Strobl, S.; Černý, Martin; Khabiti, G.; Gierl, C.

    2007-01-01

    Roč. 57, č. 7 (2007), s. 639-642 ISSN 1359-6462 Institutional research plan: CEZ:AV0Z30460519 Keywords : copper-coated iron powder * sintering * mechanical properties testing Subject RIV: JG - Metallurgy Impact factor: 2.481, year: 2007

  19. Physical Metallurgy of Rene 65, a Next-Generation Cast and Wrought Nickel Superalloy for use in Aero Engine Components

    Science.gov (United States)

    Wessman, Andrew Ezekiel

    Advancements in the design of turbine engines are in large part made possible by advancements in the capability of nickel based superalloys. Greater temperature and stress capabilities in these materials allow for increased operating temperatures and speeds in the engines, which lead to increased fuel efficiency. Early jet engines were built using austenitic stainless steels, and moved to cast and wrought nickel alloys as higher temperatures were required. By the 1970s, the state of the art nickel superalloy was Inconel 718, which is strengthened by the Ni3Nb phase known as gamma double prime. This alloy performs well and is still in heavy use in turbine engines at temperatures up to approximately 650°C (1200°F), but at higher temperatures the main strengthening precipitate phase, gamma', is thermodynamically unstable, resulting in a loss of strength following exposure to high temperature. Further advancements in nickel superalloys generally involved alloys strengthened by the Ni3Al phase known as gamma'. This precipitate is stable at much higher temperatures, but due to compositional segregation in cast and wrought processing, these alloys were processed using powder metallurgy methods, at considerable economic cost. This study will examine the microstructure of a next generation cast and wrought nickel superalloy that can provide increased temperature capability relative to Inconel 718, at lower cost than powder metallurgy superalloys. The alloy chemistry is similar to that of the powder metallurgy superalloy Rene 88DT, with changes to make it better suited for cast and wrought processing and with a different processing route from billet processing through to final part heat treatment. It is a gamma prime strengthened superalloy. The alloy has been recently introduced into service in turbine engines by GE Aviation as the alloy Rene 65, the composition of which is shown below. In this work, the following has been shown: • Rene 65 gamma' precipitate structure

  20. Resin-Powder Dispenser

    Science.gov (United States)

    Standfield, Clarence E.

    1994-01-01

    Resin-powder dispenser used at NASA's Langley Research Center for processing of composite-material prepregs. Dispenser evenly distributes powder (resin polymer and other matrix materials in powder form) onto wet uncured prepregs. Provides versatility in distribution of solid resin in prepreg operation. Used wherever there is requirement for even, continuous distribution of small amount of powder.

  1. Welding Metallurgy and Processing Issues for Joining of Power Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lienert, Thomas J. [Los Alamos National Laboratory; Reardon, Patrick T. [Los Alamos National Laboratory

    2012-08-14

    Weldability issues with the pertinent alloys have been reviewed and preliminary results of our work on Haynes 25 have been presented. Further results on the mechanical properties and metallography on the EB welds are imminent. Hot-ductility experiments will commence within a few weeks. Aging studies on the effects of heat treatment using the Gleeble are also planned. MST-6 has extensive background in the welding metallurgy of the pertinent alloys. We also have considerable experience with the various welding processes to be used.

  2. Annual report of the Metallurgy Division - period ending December 1975

    International Nuclear Information System (INIS)

    1976-01-01

    The R and D activities of the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay (India) during 1975 are described. Some of the R and D programmes of particular interest to nuclear technology are: (1) flowsheet development for the production of rare metals and alloys of nuclear use e.g. hafnium, beryllium, zirconium (2) metallurgical, irradiation hardening and corrosion studies on Zr and Zr-base alloys and (3) studies of nuclear ceramic materials such as UO2 and beryllia. (M.G.B.)

  3. CURRENT STATE AND TENDENCIES OF DEVELOPMENT OF FERROUS METALLURGY IN THE EAEU COUNTRIES

    Directory of Open Access Journals (Sweden)

    N. P. Dragun

    2016-01-01

    Full Text Available The analysis of modern status and tendencies of development of ferrous metallurgy in the countries of the EAEU is described in the article. On the basis of the conducted analysis are revealed the identified systemic problems of metallurgy and the conclusions on possible ways of their solution using the potential of integration are given.

  4. Preliminary analysis about reducing production costs in uranium mining and metallurgy at Fuzhou uranium mine

    International Nuclear Information System (INIS)

    Wu Sanmao

    1999-01-01

    The production costs in uranium ming and metallurgy have been analyzed quantitatively term by term according to present production situation for The Uranium Mining and Metallurgy Corp, which is part of Fuzhou Uranium Mine. The principal factors influencing on the production costs and the main means reducing the production costs have been found

  5. Gas-thermal coating of powdered materials. Communication 2

    International Nuclear Information System (INIS)

    Ermakov, S.S.

    1986-01-01

    This paper investigates the microstructure, microhardness, chemical composition of the transition zone, and also the strength characteristics of gas-thermal coatings including their adhesive power to the substrate (iron brand NC 100.24) and the residual stresses in the coatings. The microstructure of the transition zone was investigated; it was established that on the side of the substrate its density is greater than the mean density of both types of coating. It is shown that the porosity of the substrate has a competing effect on the thermal interaction of materials. Discovered regularities lead to the conclusion that the process of gas-thermal coating of powdered materials is more effective than when compact materials are coated; most effective is the combination of gas-thermal coating with processes of heat treatment of powder-metallurgy products

  6. NANOCOMPOSITE POWDERS FOR NEW CONTACT MATERIALS BASED ONCOPPER AND ALUMINA

    Directory of Open Access Journals (Sweden)

    Marija Korać

    2008-11-01

    Full Text Available This paper is a contribution to characterization of Cu-Al2O3 powders with nanostructure designed for the production of dispersion strengthened contact materials. New materials with predetermined properties can be successfully synthesized by utilizing the principles of hydrometallurgy and powder metallurgy. The results show a development of a new procedure for the synthesis. The applied characterization methods were differential thermal and thermogravimetric analysis (DTA-TGA, X-ray diffraction (XRD, scanning electron microscopy (SEM, Transmission Electron Microscopy (TEM: Focused Ion Beam (FIB and Analytical Electron Microscopy (AEM. Nanostructure characteristics, particle size in range 20-50 nm, and uniform distribution of dispersoide in copper matrix were validated.

  7. Microstructural Development in Al-Si Powder During Rapid Solidification

    Energy Technology Data Exchange (ETDEWEB)

    Genau, Amber Lynn [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Powder metallurgy has become an increasingly important form of metal processing because of its ability to produce materials with superior mechanical properties. These properties are due in part to the unique and often desirable microstructures which arise as a result of the extreme levels of undercooling achieved, especially in the finest size powder, and the subsequent rapid solidification which occurs. A better understanding of the fundamental processes of nucleation and growth is required to further exploit the potential of rapid solidification processing. Aluminum-silicon, an alloy of significant industrial importance, was chosen as a model for simple eutectic systems displaying an unfaceted/faceted interface and skewed coupled eutectic growth zone, Al-Si powder produced by high pressure gas atomization was studied to determine the relationship between microstructure and alloy composition as a function of powder size and atomization gas. Critical experimental measurements of hypereutectic (Si-rich) compositions were used to determine undercooling and interface velocity, based on the theoretical models which are available. Solidification conditions were analyzed as a function of particle diameter and distance from nucleation site. A revised microstructural map is proposed which allows the prediction of particle morphology based on temperature and composition. It is hoped that this work, by providing enhanced understanding of the processes which govern the development of the solidification morphology of gas atomized powder, will eventually allow for better control of processing conditions so that particle microstructures can be optimized for specific applications.

  8. The mysterious world of plutonium metallurgy: Past and future

    International Nuclear Information System (INIS)

    Hecker, S.S.; Hammel, E.F.

    1998-01-01

    The first atomic bomb detonated at the Trinity Site in New Mexico on July 16, 1945, used plutonium, a man-made element discovered < 5 yr earlier. The story of how Manhattan Project scientists and engineers tackled the mysteries of this element and fabricated it into the first atomic bomb is one of the most fascinating in the history of metallurgy and materials. The authors are currently trying to generate renewed interest in plutonium metallurgy because of the challenge posed by President Clinton, i.e., to keep the nuclear stockpile of weapons safe and reliable without nuclear testing. The stockpile stewardship challenge requires either a lifetime extension of the plutonium components or a remanufacture--neither of which can be verified by testing. In turn, this requires that one achieve a better fundamental understanding of plutonium. Of special interest is the effect of self-irradiation on the properties and on the long-term stability of plutonium and its alloys. Additional challenges arise from long-term concerns about disposing of plutonium and dealing with its environmental legacy. It is imperative to interest the next generation of students in these plutonium challenges

  9. Microstructure and properties of gravity sintered 316l stainless steel powder with nickel boride addition

    Directory of Open Access Journals (Sweden)

    Božić Dušan

    2016-01-01

    Full Text Available The present work demonstrates a procedure for synthesis of stainless steel powder by gravity sintering method. As an additive to the basic powder, NiB powder was added in the amount of 0.2 - 1.0 wt.%. Gravity sintering was done in vacuum, at the temperatures of 1100°C-1250°C, in the course of 3 - 60 min, using ceramic mould. Structural characterization was conducted by XRD, and microstructural analysis by optical and scanning electron microscope (SEM. Mechanical properties were investigated by tensile tests with steel rings. Density and permeability were determined by standard techniques for porous samples. Gravity sintered stainless steel with NiB addition had more superior mechanical and physico-chemical properties compared to stainless steel obtained by standard powder metallurgy procedures - pressing and sintering. [Projekat Ministarstva nauke Republike Srbije, br. 172005

  10. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Energy Technology Data Exchange (ETDEWEB)

    Asit Biswas Andrew J. Sherman

    2006-09-25

    This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.

  11. Uranium mining and metallurgy library information service under the network environment

    International Nuclear Information System (INIS)

    Tang Lilei

    2012-01-01

    This paper analyzes the effect of the network environment on the uranium mining and metallurgy of the information service. Introduces some measures such as strengthening professional characteristic literature resources construction, changing the service mode, building up information navigation, deepening service, meet the individual needs of users, raising librarian's quality, promoting the co-construction and sharing of library information resources, and puts forward the development idea of uranium mining and metallurgy library information service under the network environment. (author)

  12. Production of uranium in Navoi Mining and Metallurgy Combinat, Uzbekistan

    International Nuclear Information System (INIS)

    Kuchersky, N.; Tolstov, E.A.; Mazurkevich, A.P.; Inozemzev, S.B.

    2001-01-01

    Full text: Under the conditions of constantly increasing level of development of the nuclear power, it is inevitable that the uranium stockpiles accumulated to 1985 will soon be depleted. This consideration underlies the development concept of uranium production in the Navoi Mining and Metallurgy Combinat, Uzbekistan. Because this product has become a source of hard currency revenues for the Republic, there will be a significant increase in the processed ore and output of uranium oxide within the next few years. Uranium production in the Navoi Mining and Metallurgy Combinat represents a full-cycle operations ranging from geological survey through hydrometallurgical processing resulting in the output of uranium concentrate in the form of uranium protoxide-oxide (U 3 O 8 ). The NMMC uranium operations include the Hydrometallurgical Plant and three facilities accomplishing ISL mining facilities. A successful start on the development of the Uchkuduk deposit by ISL method in the 1960s gave rise to scientific and production approach for development of other uranium deposits of the infiltration bedded (sandstone) type. Uranium recovery by ISL has become a separate mining branch within the 30-year period of its history and the contribution of this branch in uranium production has steadily grown. Since 1995 all uranium produced by Navoi Mining and Metallurgy Combinat is attributed to ISL. During this evolution period of the ISL method, a whole range of systematic scientific research and practical works were carried out covering improvement of process flowsheets, equipment, operational methods and techniques for particular mining conditions at those specific sites. In co-operation with design and scientific research institutions, a significant number of scientific researches, test works, design and engineering projects were achieved in order to create optimal conditions for ISL mining and further processing of pregnant solutions by sorption as well as to appropriately equip

  13. Development and application of characteristic database for uranium mining and metallurgy in the library of Beijing Research Institute of Chemical Engineering and Metallurgy

    International Nuclear Information System (INIS)

    Gao Renxi

    2012-01-01

    Beijing Research Institute of Chemical Engineering and Metallurgy (BRICEM) is a multi disciplinary comprehensive research institute engaged in uranium mining, engineering design and related material researches. After 53 years of researches and development, BRICEM has accumulated a plenty of valuable data and resources. By analyzing the actual conditions of BRICEM's technological database, this thesis aims to propose the idea of building a characteristic database for uranium mining and metallurgy. It gives an in-depth analysis on content design, development status and problems of database development, in order to come up with solutions to these problems, as well as suggestions on the future development plans of the characteristic database. (author)

  14. Granulation of fine powder

    Science.gov (United States)

    Chen, Ching-Fong

    2016-08-09

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to form a dense compact with a higher density and more uniform pore size distribution.

  15. Simplification of the processing of milled aluminium powder and mechanical evaluation properties

    International Nuclear Information System (INIS)

    Cintas, J.; Rodriguez, J. A.; Gallardo, J. M.; Herrera, E. J.

    2001-01-01

    An alternative powder.metallurgy consolidation method of milled aluminium (M Al) powder, consisting in a double cycle of cold pressing and vacuum sintering, has been developed. The aim of the present investigation is to simplify this consolidation method, from the original five steps to only three steps. This would be possible since milled powders soften during desassing, at high temperature. The mechanical properties of compacts (hardness at room and high temperature, ultimate tensile strength and elongation) obtained by the three-step and the five-step processing are comparable. This process could be ol special interest for the manufacturing of large series of small parts, such as are used in the automotive industry. (Author) 10 refs

  16. Operation whey powder

    International Nuclear Information System (INIS)

    Brunner, E.

    1987-01-01

    The odyssey of the contaminated whey powder finally has come to an end, and the 5000 tonnes of whey now are designated for decontamination by means of an ion exchange technique. The article throws light upon the political and economic reasons that sent the whey powder off on a chaotic journey. It is worth mentioning in this context that the natural radioactivity of inorganic fertilizers is much higher than that of the whey powder in question. (HP) [de

  17. Neutron powder diffraction

    International Nuclear Information System (INIS)

    David, W.I.F.

    1990-01-01

    Neutron powder diffraction is a powerful technique that provides a detailed description of moderately complex crystal structures. This is nowhere more apparent than in the area of high temperature superconductors where neutron powder diffraction has provided precise structural and magnetic information, not only under ambient conditions but also at high and low temperatures and high pressures. Outside superconductor research, the variety of materials studied by neutron powder diffraction is equally impressive including zeolites, fast ionic conductors, permanent magnets and materials undergoing phase transitions. Recent advances that include high resolution studies and real-time crystallography are presented. Future possibilities of neutron powder diffraction are discussed

  18. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  19. Advance on Al2O3 Particulates Reinforced Aluminum Metal Matrix Composites (Al-MMCs Manufactured by the Power Metallurgy(PM Methods- Improved PM Techniques

    Directory of Open Access Journals (Sweden)

    Xu Lina

    2016-01-01

    Full Text Available Aluminum metal matrix composites (Al-MMCs with Al2O3 particulates as reinforcement fabricated by the power metallurgy (PM methods have gained much attention due to their unique characteristics of the wide range of Al2O3 particles addition, easy-operating process and effectiveness. The improved PM techniques, such as the high energy ball milling, powder extruder and high pressure torsion were applied to further strengthening the properties or/and diminishing the agglomeration of strength particles. The formation of liquid phase assisted densification of compacts to promote the sintering of composites. Complex design of Al2O3 particles with other particles was another efficient method to tailor the properties of Al-MMCs.

  20. Surface chemical state of Ti powders and its alloys: Effect of storage conditions and alloy composition

    Energy Technology Data Exchange (ETDEWEB)

    Hryha, Eduard, E-mail: hryha@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE - 412 96 Gothenburg (Sweden); Shvab, Ruslan [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE - 412 96 Gothenburg (Sweden); Bram, Martin; Bitzer, Martin [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), D-52425 Jülich (Germany); Nyborg, Lars [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Rännvägen 2A, SE - 412 96 Gothenburg (Sweden)

    2016-12-01

    Highlights: • Powder particles of Ti, NiTi and Ti6Al4V are covered by homogeneous Ti-oxide layer. • Thickness of the Ti-oxide layer is in the range of 2.9 to 4.2 nm in as-atomized state. • Exposure to the air results in immediate oxide thickness increase of up to 30%. • Oxide thickness increase of only 15% during storage for 8 years. • High passivation of the Ti, NiTi and Ti6Al4V powder surface by Ti-oxide layer. - Abstract: High affinity of titanium to oxygen in combination with the high surface area of the powder results in tremendous powder reactivity and almost inevitable presence of passivation oxide film on the powder surface. Oxide film is formed during the short exposure of the powder to the environment at even a trace amount of oxygen. Hence, surface state of the powder determines its usefulness for powder metallurgy processing. Present study is focused on the evaluation of the surface oxide state of the Ti, NiTi and Ti6Al4V powders in as-atomized state and after storage under air or Ar for up to eight years. Powder surface oxide state was studied by X-ray photoelectron spectroscopy (XPS) and high resolution scanning electron microscopy (HR SEM). Results indicate that powder in as-atomized state is covered by homogeneous Ti-oxide layer with the thickness of ∼2.9 nm for Ti, ∼3.2 nm and ∼4.2 nm in case of Ti6Al4V and NiTi powders, respectively. Exposure to the air results in oxide growth of about 30% in case of Ti and only about 10% in case of NiTi and Ti6Al4V. After the storage under the dry air for two years oxide growth of only about 3-4% was detected in case of both, Ti and NiTi powders. NiTi powder, stored under the dry air for eight years, indicates oxide thickness of about 5.3 nm, which is about 30% thicker in comparison with the as-atomized powder. Oxide thickness increase of only ∼15% during the storage for eight years in comparison with the powder, shortly exposed to the air after manufacturing, was detected. Results indicate a

  1. Research on Semisolid Microstructural Evolution of 2024 Aluminum Alloy Prepared by Powder Thixoforming

    Directory of Open Access Journals (Sweden)

    Pubo Li

    2015-04-01

    Full Text Available A novel method, powder thixoforming, for net-shape forming of the particle-reinforced Aluminum matrix composites in semi-solid state has been proposed based on powder metallurgy combining with thixoforming technology. The microstructural evolution and phase transformations have been investigated during partial remelting of the 2024 bulk alloy, prepared by cold pressing of atomized alloy powders to clarify the mechanisms of how the consolidated powders evolve into small and spheroidal primary particles available for thixoforming. The effect of heating temperature on the resulting semisolid microstructure has also been discussed. The results indicate that the microstructural evolution includes three stages—the initial rapid coarsening of the fine grains within the powders, the formation of continuous liquid layer on the primary particle surface (the original powder, and the final coarsening—that result from the phase transformations of θ→α, α→L, and α→L and L→α, respectively. The coarsening rate of the primary particles is low, and one original powder always evolves into one spheroidal particle with a continuous liquid layer surface. Properly raising the heating temperature is beneficial for obtaining an ideal semisolid microstructure.

  2. The traces of roman metallurgy in Eastern Serbia

    Directory of Open Access Journals (Sweden)

    Petković Sofija

    2009-01-01

    Full Text Available The archaeological traces of the Roman mining and metallurgy in eastern Serbia are rather frequent but insufficiently studied and published. Three mining-metallurgical regions abounding in gold, silver, copper, iron and lead could be distinguished there: 1. the upper course of the Pek river, metalla Pincensia, 2. the area between Bor, Zlot, Crna Reka and Rgotina and 3. the area in the river basin of Beli Timok, two latter ones had been organized as territoria metallorum. The archeometallurgical sites confirmed by investigations are: Kraku lu Jordan at the confluence of the Brodica river and the Pek river, Rudna Glava, Tilva Roš in Bor, Gamzigrad - Romuliana, Rgotina near Zaječar and Timacum Minus in the village Ravna near Knjaževac. Roman mining-metallurgical activities in eastern Serbia flourished from the end of the 3rd century, were interrupted by the invasion of Huns in AD 441. and restored in the time of emperors Anastasius and Justin I, in the end of the 5th - beginning of the 6th centuries. The Roman mining-metallurgical centers functioned in the 6th century until the Slav invasion in the beginning of the 7th century.

  3. TRADITIONAL METALLURGY, NANOTECHNOLOGIES AND STRUCTURAL MATERIALS: A SORBY AWARD LECTURE

    Energy Technology Data Exchange (ETDEWEB)

    Louthan, M

    2007-07-17

    Traditional metallurgical processes are among the many ''old fashion'' practices that use nanoparticles to control the behavior of materials. Many of these practices were developed long before microscopy could resolve nanoscale features, yet the practitioners learned to manipulate and control microstructural elements that they could neither see nor identify. Furthermore, these early practitioners used that control to modify microstructures and develop desired material properties. Centuries old colored glass, ancient high strength steels and medieval organ pipes derived many of their desirable features through control of nanoparticles in their microstructures. Henry Sorby was among the first to recognize that the properties of rocks, minerals, metals and organic materials were controlled by microstructure. However, Mr. Sorby was accused of the folly of trying to study mountains with a microscope. Although he could not resolve nanoscale microstructural features, Mr. Sorby's observations revolutionized the study of materials. The importance of nanoscale microstructural elements should be emphasized, however, because the present foundation for structural materials was built by manipulating those features. That foundation currently supports several multibillion dollar industries but is not generally considered when the nanomaterials revolution is discussed. This lecture demonstrates that using nanotechnologies to control the behavior of metallic materials is almost as old as the practice of metallurgy and that many of the emergent nanomaterials technologists are walking along pathways previously paved by traditional metallurgists.

  4. [Possible health effects associated with Pre-Columbian metallurgy].

    Science.gov (United States)

    Idrovo, Alvaro Javier

    2005-09-01

    In the Old World, several researchers have indicated that adverse health effects were associated with exposure to arsenic, and that this influenced a change in the use of copper-arsenic alloys to others less toxic. This hypothesis was evaluated for three Pre-Columbian metallurgy traditions: Central Andes, Intermediate Area, and West Mexico. The metal artifacts from the Central Andes showed arsenic concentrations similar to those in the Old World (0.5%-1.0%). In the Intermediate Area the values were smallest; however, in West Mexico the arsenic content was very high (7%-25%). In Central Andes arsenical bronze was used initially, but copper-tin alloys when introduced were preferred and distributed throughout the Inca Empire. Osteological and artistic evidences of foot amputations among Moche individuals from Central Andes support the presence of "black foot disease" (a condition associated with arsenic poisoning) among Pre-Columbian populations. In conclusion, the adverse effects of arsenic have been observed in the New World, and that these effects promoted a change toward the use of less toxic alloys.

  5. Novel Method for Making Biomedical Segregation-Free Ti-30Ta Alloy Spherical Powder for Additive Manufacturing

    Science.gov (United States)

    Xia, Yang; Fang, Zhigang Zak; Sun, Pei; Zhang, Ying; Zhu, Jun

    2018-01-01

    Ti-Ta alloys offer a good combination of high strength and low modulus among Ti-based alloys, and are ideal for biomedical applications. However, making Ti-Ta alloys has always been challenging because they tend to suffer from compositional segregation during melting due to the large difference between the melting points of Ti and Ta. This article describes a novel process for making spherical Ti-30Ta alloy powder through a unique powder metallurgy technique, namely the granulation-sintering-deoxygenation process. The results indicate that the compositional segregation problem can be overcome using this process technology. Combined with use of a deoxygenation process, the critical interstitial element, oxygen, can be controlled to < 400 ppm for powder with particle size < 75 µm. The destabilization effect of Ta on Ti-O solid solutions, and the resulting improved deoxygenation process for Ti-Ta, are discussed, as well as the phase composition and microstructure of the powders.

  6. Novel Method for Making Biomedical Segregation-Free Ti-30Ta Alloy Spherical Powder for Additive Manufacturing

    Science.gov (United States)

    Xia, Yang; Fang, Zhigang Zak; Sun, Pei; Zhang, Ying; Zhu, Jun

    2018-03-01

    Ti-Ta alloys offer a good combination of high strength and low modulus among Ti-based alloys, and are ideal for biomedical applications. However, making Ti-Ta alloys has always been challenging because they tend to suffer from compositional segregation during melting due to the large difference between the melting points of Ti and Ta. This article describes a novel process for making spherical Ti-30Ta alloy powder through a unique powder metallurgy technique, namely the granulation-sintering-deoxygenation process. The results indicate that the compositional segregation problem can be overcome using this process technology. Combined with use of a deoxygenation process, the critical interstitial element, oxygen, can be controlled to < 400 ppm for powder with particle size < 75 µm. The destabilization effect of Ta on Ti-O solid solutions, and the resulting improved deoxygenation process for Ti-Ta, are discussed, as well as the phase composition and microstructure of the powders.

  7. Indexation Rules for Metallurgy in PASCAL. Original Title: Regles d'Indexation de la Metallurgie'--Technical Note Issued by Informascience--January 1980. Translated by Marie Wallin.

    Science.gov (United States)

    Royal Inst. of Tech., Stockholm (Sweden). Library.

    The indexing rules presented are designed for use with a new French-German database on metallurgy being developed under an agreement by CNRS (Centre National de la Recherche Scientifique, Paris) and BAM (Bundesanstalt fur Materialprufung, Berlin). The new database, which will feature multilingual titles and index terms (French-German-English-) and…

  8. High Performance MG-System Alloys For Weight Saving Applications: First Year Results From The Green Metallurgy EU Project

    Science.gov (United States)

    D'Errico, Fabrizio; Plaza, Gerardo Garces; Hofer, Markus; Kim, Shae K.

    The GREEN METALLURGY Project, a LIFE+ project co-financed by the EU Commission, has just concluded its first year. The Project seeks to set manufacturing processes at a pre-industrial scale for nanostructured-based high-performance Mg-Zn(Y) magnesium alloys. The Project's goal is the reduction of specific energy consumed and the overall carbon-footprint produced in the cradle-to-exit gate phases. Preliminary results addressed potentialities of the upstream manufacturing process pathway. Two Mg-Zn(Y) system alloys with rapid solidifying powders have been produced and directly extruded for 100% densification. Examination of the mechanical properties showed that such materials exhibit strength and elongation comparable to several high performing aluminum alloys; 390 MPa and 440 MPa for the average UTS for two different system alloys, and 10% and 15% elongations for two system alloys. These results, together with the low-environmental impact targeted, make these novel Mg alloys competitive as lightweight high-performance materials for automotive components.

  9. [Atmospheric emission of PCDD/Fs from secondary aluminum metallurgy industry in the southwest area, China].

    Science.gov (United States)

    Lu, Yi; Zhang, Xiao-Ling; Guo, Zhi-Shun; Jian, Chuan; Zhu, Ming-Ji; Deng, Li; Sun, Jing; Zhang, Qin

    2014-01-01

    Five secondary aluminum metallurgy enterprises in the southwest area of China were measured for emissions of PCDD/Fs. The results indicated that the emission levels of PCDD/Fs (as TEQ) were 0.015-0.16 ng x m(-3), and the average was 0.093 ng x m(-3) from secondary aluminum metallurgy enterprises. Emission factors of PCDD/Fs (as TEQ) from the five secondary aluminum metallurgy enterprises varied between 0.041 and 4.68 microg x t(-1) aluminum, and the average was 2.01 microg x t(-1) aluminum; among them, PCDD/Fs emission factors from the crucible smelting furnace was the highest. Congener distribution of PCDD/F in stack gas from the five secondary aluminum metallurgies was very different from each other. Moreover, the R(PCDF/PCDD) was the lowest in the enterprise which was installed only with bag filters; the R(PCDF/PCDD) were 3.8-12.6 (the average, 7.7) in the others which were installed with water scrubbers. The results above indicated that the mechanism of PCDD/Fs formation was related to the types of exhaust gas treatment device. The results of this study can provide technical support for the formulation of PCDD/Fs emission standards and the best available techniques in the secondary aluminum metallurgy industry.

  10. Effect of electrolysis parameters on the morphologies of copper powder obtained at high current densities

    Directory of Open Access Journals (Sweden)

    Orhan Gökhan

    2012-01-01

    Full Text Available The effects of copper ion concentrations and electrolyte temperature on the morphologies and on the apparent densities of electrolytic copper powders at high current densities under galvanostatic regime were examined. These parameters were evaluated by the current efficiency of hydrogen evolution. In addition, scanning electron microscopy was used for analyzing the morphology of the copper powders. It was found that the morphology was dependent over the copper ion concentration and electrolyte temperature under same current density (CD conditions. At 150 mA cm-2 and the potential of 1000±20 mV (vs. SCE, porous and disperse copper powders were obtained at low concentrations of Cu ions (0.120 M Cu2+ in 0.50 M H2SO4. Under this condition, high rate of hydrogen evolution reaction took place parallel to copper electrodeposition. The morphology was changed from porous, disperse and cauliflower-like to coral-like, shrub-like and stalk-stock like morphology with the increasing of Cu ion concentrations towards 0.120 M, 0.155 M, 0.315 M, 0.475 M and 0.630 M Cu2+ in 0.5 M H2SO4 respectively at the same CD. Similarly, as the temperature was increased, powder morphology and apparent density were observed to be changed. The apparent density values of copper powders were found to be suitable for many of the powder metallurgy applications.

  11. Path dependence and strength anisotropy of mechanical behavior in cold-compacted powders

    Science.gov (United States)

    Galen, Steven A.

    2005-12-01

    The problem of compaction of powders at low homologous temperatures has been studied over the last twenty years in many fields including powder metallurgy, ceramics, pharmaceutical, agricultural, and mining. Recent emphasis of research efforts has been on the use of phenomenological models that are capable of predicting compaction loads and density distributions in the final product. However, the mechanical properties of the compact cannot be predicted from current models since they consider strength as a function of density alone. A number of studies have shown that strength is dependent on other variables besides density, including the stress path used for consolidation. In prior work, path dependence in ductile powders has been shown experimentally. In this thesis, a ceramic, dibasic calcium phosphate, was consolidated using a variety of stress paths, ranging from nearly isostatic to nearly closed-die. Yield loci were shown to be dependent on stress path as well as compact density. Strength anisotropy in ductile and brittle powders was shown to exist after closed-die compaction and is dependent on compact density. Ductile powders become increasingly anisotropic with density. Brittle powders exhibit anisotropy during the early stages of compaction, but this diminishes as densification continues. Separate mechanisms to explain these behaviors are proposed and supported with experimental data from tensile strength testing, SEM fracture surface analysis and surface area testing. Finally, path dependence and strength anisotropy are shown to have a common origin, namely, directionality of microstructure resulting from initial particle morphology and particle deformation during compaction.

  12. Porous Nb-Ti based alloy produced from plasma spheroidized powder

    Directory of Open Access Journals (Sweden)

    Qijun Li

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

  13. Progress report of the Metallurgy Division for the period 1978-1980

    International Nuclear Information System (INIS)

    Sharma, B.D.; Mohan, Ashok; Bose, D.K.; Rao, C.N.; Chouthai, S.S.

    1980-01-01

    The research and development (R and D) work of the Metallurgy Division of the Bhabha Atomic Research Centre at Bombay for the period 1978-1980 is reported in the form of individual summaries under the headings: extractive metallurgy section, physical metallurgy section, corrosion and electrometallurgy section, ceramics section. Progress of work of beryllium pilot plant project, programme for R-5 utilisation for materials irradiation research project, development of rare, reactive and refractory metals, and development of ceramics materials for MHD programme is surveyed. Lists of publications, deputations, visits, conferences, colloquia are given. A chart at the end shows the various sections of the Division and personnel in each section. (M.G.B.)

  14. 76 FR 64344 - Amended Record of Decision for the Nuclear Facility Portion of the Chemistry and Metallurgy...

    Science.gov (United States)

    2011-10-18

    ... the same sets of safety controls and key equipment. Further, as the SEIS analysis indicates, once... Nuclear Facility Portion of the Chemistry and Metallurgy Research Building Replacement Project at Los...) for the Nuclear Facility portion of the Chemistry and Metallurgy Research Building Replacement (CMRR...

  15. OIL SOLUTIONS POWDER

    Science.gov (United States)

    Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.

  16. Magnetically responsive enzyme powders

    Science.gov (United States)

    Pospiskova, Kristyna; Safarik, Ivo

    2015-04-01

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (-20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties.

  17. Modernization of the Ural Metallurgy during the Great Patriotic War (1941–1945

    Directory of Open Access Journals (Sweden)

    Vladimir V. Zaparii

    2013-09-01

    Full Text Available The article characterizes the Ural industry modernization in war footing, shows the significance of evacuation of enterprises from the Western areas of the country to the region, reveals their role in the formation of a new metallurgical center of modern metallurgy in terms of human resources and manufacture. Innovations in metallurgy, the role of human factor in solving industrial restructuring problem are examined. Forms and methods of science use for the industrial modernization are considered. Solving of human resources problem is shown. The author touches upon the problem of metallurgical sector management in wartime. The role of people’s heroism in this difficult period of Russian history is discussed.

  18. Metallurgy of high-silicon steel parts produced using Selective Laser Melting

    OpenAIRE

    Garibaldi, Michele; Ashcroft, Ian; Simonelli, Marco; Hague, Richard

    2016-01-01

    The metallurgy of high-silicon steel (6.9%wt.Si) processed using Selective Laser Melting (SLM) is presented for the first time in this study. High-silicon steel has great potential as a soft magnetic alloy, but its employment has been limited due to its poor workability. The effect of SLM-processing on the metallurgy of the alloy is investigated in this work using microscopy, X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). XRD analysis suggests that the SLM high-silicon s...

  19. [Analysis of changes in characteristics of arterial hypertension occupational risk in workers of nonferrous metallurgy].

    Science.gov (United States)

    Vlasova, E M; Shliapnikov, D M; Lebedeva, T M

    2015-01-01

    The article covers changes in occupational cardiovascular risk for workers of nonferrous,metallurgy. Findings are that exposure to noise up to 94 dB with length of service increases possible atherosclerosis and metabolic syndrome. With 5 years of service, risk of the predicted conditions increases by 40.5%. When occupational exposure lasts over 5 years, risk of arterial hypertension increases. A group of workers without exposure to occupational factors appeared to have no connection between length of service and metabolic syndrome and arterial hypertension. Risk evolution modelling proved that risk of functional disorders in nonferrous metallurgy workers becomes unacceptable after 5 years of service (cardiovascular disorders are critical).

  20. Magnetically responsive enzyme powders

    International Nuclear Information System (INIS)

    Pospiskova, Kristyna; Safarik, Ivo

    2015-01-01

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction

  1. Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Quy Bau Nguyen

    2017-10-01

    Full Text Available In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing (AM were studied using different powder characterization techniques. The results revealed that the particle size distribution (PSD for the selective laser melting (SLM process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·(50 g−1. In addition, the packing density was found to be 60%. The rheological test results indicate that the virgin powder has reasonably good flowability compared with the recycled powder. The inter-relation between the powder characteristics is discussed herein. A propeller was successfully printed using the powder. The results suggest that Inconel powder is suitable for AM and can be a good reference for researchers who attempt to produce AM powders.

  2. Enery Efficient Press and Sinter of Titanium Powder for Low-Cost Components in Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Zwitter; Phillip Nash; Xiaoyan Xu; Chadwick Johnson

    2011-03-31

    This is the final technical report for the Department of Energy NETL project NT01931 Energy Efficient Press and Sinter of Titanium Powder for Low-Cost Components in Vehicle Applications. Titanium has been identified as one of the key materials with the required strength that can reduce the weight of automotive components and thereby reduce fuel consumption. Working with newly developed sources of titanium powder, Webster-Hoff will develop the processing technology to manufacture low cost vehicle components using the single press/single sinter techniques developed for iron based powder metallurgy today. Working with an automotive or truck manufacturer, Webster-Hoff will demonstrate the feasibility of manufacturing a press and sinter titanium component for a vehicle application. The project objective is two-fold, to develop the technology for manufacturing press and sinter titanium components, and to demonstrate the feasibility of producing a titanium component for a vehicle application. The lowest cost method for converting metal powder into a net shape part is the Powder Metallurgy Press and Sinter Process. The method involves compaction of the metal powder in a tool (usually a die and punches, upper and lower) at a high pressure (up to 60 TSI or 827 MPa) to form a green compact with the net shape of the final component. The powder in the green compact is held together by the compression bonds between the powder particles. The sinter process then converts the green compact to a metallurgically bonded net shape part through the process of solid state diffusion. The goal of this project is to expand the understanding and application of press and sinter technology to Titanium Powder applications, developing techniques to manufacture net shape Titanium components via the press and sinter process. In addition, working with a vehicle manufacturer, demonstrate the feasibility of producing a titanium component for a vehicle. This is not a research program, but rather a

  3. Metallurgy, environmental pollution and the decline of Etruscan civilisation.

    Science.gov (United States)

    Harrison, Adrian P; Cattani, Ilenia; Turfa, Jean M

    2010-01-01

    The Etruscans were justifiably famous in antiquity for their advanced metallurgy and for the rich mineral resources of their region (including La Tolfa, the Colline Metallifere, Mont'Amiata and Elba). We offer a new perspective on certain Iron Age and Archaic (ca. 1,000-480 BC: ) Etruscan industrial and habitation sites, and on the problem of heavy metal poisoning, still being investigated today, coincidentally in some of the same areas that originally saw Etruscan mines and workshops. This study investigates ancient sources, including literature and excavation reports, in the light of modern studies of heavy metal poisoning on human beings, plant and animal life. Furthermore, it is the first to use non-invasive Niton X-ray fluorescence analysis of samples of Etruscan (strictly ethnically Faliscan) hair (c. 350 BCE: ). The findings show the strong likelihood of heavy metal poisoning in areas of Etruscan metallurgical activity with the effects of this being responsible for or contributing to the abandonment of a number of these sites around the 6th century BC: . No thoroughly satisfactory explanation of this phenomenon has previously been offered. However, findings suggest that Faliscan women, represented by sample CG 2004-6-2, were not exposed to high levels of arsenic in life, which is not perhaps surprising for an urban aristocratic woman of the mid-4th century BC: . The reasons for the abandonment of several flourishing settlements are without doubt complex, and include political and social change. We suggest heavy metal contamination as an additional stimulus to the noted phenomenon of the peaceful abandonment, at the beginning, and at the end of the 6th century BC: , of sites in southern and northern Etruria such as Marsiliana d'Albegna (late 7th c.), Lago dell'Accesa, Acquarossa and Poggio Civitate-Murlo (late 6th c.). While the historical truth of the demise of Etruscan civilisation is much more complex, an interim set of related events, the desertion of

  4. ROLLING CONTACT FATIGUE AND WEAR OF CrL AND CrM MODE POWDER METALLURGY STEELS

    Directory of Open Access Journals (Sweden)

    Dušan Rodziňák

    2010-03-01

    Full Text Available Contact fatigue properties of sintered steels type CrM and CrL with addition of 0,3-0,7 %C were examined on the device type „pin on disc“ and confronted with wear tests on the same principle. Achieved outcomes are better for CrM material; the higher carbon content the better they are. Fatigue strength ranges from 925 - 1410 MPa and is consistent with the value of hardness. Dry wear tests show that the wear is dependent on the hardness of carbide particles (microhardness and not on macrohardness of material. These causes wear of indentor. Between values obtained from tests of contact fatigue and wear testing is not possible to find relevant compliance. Both rupture mechanisms are based on breaches of other principles, particularly the PM materials are in the mode of wear that is not sufficiently explored.

  5. Metallurgical Variables Influencing the Corrosion Susceptibility of P/M (Powder Metallurgy) 7091 Aluminum/SiCw Composite.

    Science.gov (United States)

    1985-10-01

    weighing specimens in air and in distilled water (T=25’C). For all density calculations, the SiCw distribution was assumed to be uniform throughout the...0.099 0.090 iauv.A/ omw 7.0x10 " 7.Ox10 7 2x10 " 6X10 " 14 NADC-86071-60 The effect of potential on the A(T6) material, was determined by applying a

  6. Surface modification of pharmaceutical powders

    OpenAIRE

    Zhou, Qi

    2017-01-01

    This thesis describes a body of work to investigate a mechanical dry powder coating approach aiming to modify the surface properties of fine pharmaceutical powders. Powders were coated with magnesium stearate (MgSt) in order to improve their bulk powder properties such as flowability, fluidization and aerosolization. The flow characteristics of a cohesive milled lactose monohydrate powder (Pharmatose® 450M, VMD around 20 μm) were substantially improved by processing with 1% w/w magn...

  7. Powder metallurgical high performance materials. Proceedings. Volume 1: high performance P/M metals

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of this sequence of seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

  8. Powder metallurgical high performance materials. Proceedings. Volume 2: P/M hard materials

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

  9. Uranium mining and metallurgy library science and technology literature retrieval of network

    International Nuclear Information System (INIS)

    Tang Lilei

    2014-01-01

    This paper introduces the network resources and characteristics retrieve service of Beijing research Institute of Chemical Engineering of Metallurgy library, Analyzes the problems often encountered in the literature retrieval in science and technology, And puts forward the solution, Puts forward the thinking and Suggestions of science and technology literature retrieval. (author)

  10. Solvent Extraction of Copper: An Extractive Metallurgy Exercise for Undergraduate Teaching Laboratories

    Science.gov (United States)

    Smellie, Iain A.; Forgan, Ross S.; Brodie, Claire; Gavine, Jack S.; Harris, Leanne; Houston, Daniel; Hoyland, Andrew D.; McCaughan, Rory P.; Miller, Andrew J.; Wilson, Liam; Woodhall, Fiona M.

    2016-01-01

    A multidisciplinary experiment for advanced undergraduate students has been developed in the context of extractive metallurgy. The experiment serves as a model of an important modern industrial process that combines aspects of organic/inorganic synthesis and analysis. Students are tasked to prepare a salicylaldoxime ligand and samples of the…

  11. Metallurgy department progress report for the period 1 January to 31 December 1981

    International Nuclear Information System (INIS)

    1982-07-01

    The activities of the Metallurgy Department at Risoe during 1981 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1981 is included. (author)

  12. Metallurgy department progress report for the period 1 January to 31 December 1982

    International Nuclear Information System (INIS)

    1983-07-01

    The activities of the Metallurgy Department at Risoe during 1982 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Deveopment, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1982 is included. (author)

  13. Recycling of wastes from uranium mining and metallurgy and recovery of useful resources in China

    International Nuclear Information System (INIS)

    Pan Yingjie; Xue Jianxin; Chen Zhongqiu

    2012-01-01

    Recycling of wastes from uranium mining and metallurgy in China and recovery of useful resources are summarized from the aspects such as recovery of uranium from mine water, reusing of waste water, decontaminating and recycling of radioactivity contaminated metal, backfill of gangues and tailings, and comprehensive recovery and utilization of associated uranium deposits. (authors)

  14. Practical application of solid phase spectrophotometry in analysis of materials and goods of mining and metallurgy

    International Nuclear Information System (INIS)

    Duan Qunzhang

    1999-01-01

    The author reviewed recent development and practical application of solid phase spectrophotometry in analysis of materials and goods of mining-metallurgy. Separation and preconcentration and conditions of coloring determination, sensitivity and range of detection, as well as interference of corresponding method are discussed

  15. Annual report of the Metallurgy Division [for the] period ending December 1977

    International Nuclear Information System (INIS)

    Elayaperumal, K.; Sridhar Rao, Ch.; Mukhopadhyay, P.; Rao, S.V.K.

    1979-01-01

    The research and development work carried out and the various programmes underway in the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay, during the calendar year 1977 have been reported. The R and D work and programmes cover extraction metallurgy, physical metallurgy, alloy development, corrosion metallurgy and ceramics. Some of the major studies and programmes are: (1) development of processes for extraction of niobium, vanadium, hafnium and nickel, (2) preparation of niobium alloys, ferro-zirconium, ceramic grade zirconia, (3) electro-refining of zircaloy scrap, (4) preparation of anhydrous beryllium fluoride from Indian beryl, (5) preparation of beryllium alloys, (6) studies on phase transformation and deformation behaviour of zirconium and zirconium-oxygen alloys, (7) self-diffusion studies in dilute Zr-Fe and Zr-Cr alloys, (8) studies on corrosion and stress corrosion cracking of zirconium base alloys and (9) sintering studies on ZrO 2 -PuO 2 and BeO. (M.G.B.)

  16. Metallurgy Department progress report for the period 1 January to 31 December 1984

    International Nuclear Information System (INIS)

    1985-04-01

    The activities of the Metallurgy Department at Risoe during 1984 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1984 is included. (author)

  17. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

    Science.gov (United States)

    Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

    2017-01-31

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  18. A Guide for Planning Facilities for Occupational Preparation Programs in Metallurgy Technology. Interim Report. Research 28.

    Science.gov (United States)

    German, Carl, Jr.

    The major purpose of this guide is to elicit the information necessary for writing educational specifications for facilities to house technical education programs in metallurgy. It is organized in these parts: (1) Part I discusses the major purpose, underlying assumptions, recent instructional trends, and guiding principles utilized in the…

  19. Prerequisites and opportunities for repositioning of the Urals metallurgy within the Industry 4.0

    Directory of Open Access Journals (Sweden)

    O. A. Romanova

    2017-12-01

    Full Text Available The authors present the modern trends in the development of metallurgy, and classify the technological structure of metallurgical industry. The article contains specific features of the development of metallurgy in the conditions of industry formation. A special role in this process plays the pace of digitalization and robotization of the industry, the development of additive technologies, Internet of things. The authors substantiate the possibility of developing the metallurgy of the Middle Urals as a science-intensive, high-tech complex that meets the requirements of Industry 4.0. This possibility interrelates with its repositioning, one of the main tasks of which is the formation of new sales markets focused on high-tech consumer industries, as well as the preservation of traditional consumption sectors under conditions of increasing competition in the construction materials market. The authors underline the importance of international cooperation in the field of environmentally safe industrial development, with applying the best available technologies and innovative development in general. The authors propose a methodological approach for assessing the repositioning of the regional metallurgical complex. This approach is the consecutive implementation of the following stages: assessment of dynamics and the forecast of development of consumer steel products sector and its structure based on identified priority areas of technological development of metallurgy in the region; construction of a factor model describing the changes in parameters of the RMC repositioning process, and approximation of the characteristics of their nonlinear elements; building a mathematical model on the basis of neural network algorithms for assessing the process of repositioning the RMC, taking into account projected values of the RMK parameters in the process of repositioning and changing the structure of consumer markets for metal products; formation of a variable

  20. Ultrasonic characterization of microstructure in powder metal alloy

    Science.gov (United States)

    Tittmann, B. R.; Ahlberg, L. A.; Fertig, K.

    1986-01-01

    The ultrasonic wave propagation characteristics were measured for IN-100, a powder metallurgy alloy used for aircraft engine components. This material was as a model system for testing the feasibility of characterizing the microstructure of a variety of inhomogeneous media including powder metals, ceramics, castings and components. The data were obtained for a frequency range from about 2 to 20 MHz and were statistically averaged over numerous volume elements of the samples. Micrographical examination provided size and number distributions for grain and pore structure. The results showed that the predominant source for the ultrasonic attenuation and backscatter was a dense (approx. 100/cubic mm) distribution of small micropores (approx. 10 micron radius). Two samples with different micropore densities were studied in detail to test the feasibility of calculating from observed microstructural parameters the frequency dependence of the microstructural backscatter in the regime for which the wavelength is much larger than the size of the individual scattering centers. Excellent agreement was found between predicted and observed values so as to demonstrate the feasibility of solving the forward problem. The results suggest a way towards the nondestructive detection and characterization of anomalous distributions of micropores when conventional ultrasonic imaging is difficult. The findings are potentially significant toward the application of the early detection of porosity during the materials fabrication process and after manufacturing of potential sites for stress induced void coalescence leading to crack initiation and subsequent failure.

  1. The role of the native oxide shell on the microwave sintering of copper metal powder compacts

    International Nuclear Information System (INIS)

    Mahmoud, Morsi M.; Link, Guido; Thumm, Manfred

    2015-01-01

    Highlights: • Thin oxide native layer had a critical role on microwave sintering of copper. • Explain why microwaves interact with copper powder differently than its bulk. • Abnormal expansion in copper is due to the plastic deformation and crack formation. • In-situ setup gives important insight about the microwave sintering of metals. • Microwave sintering is a promising candidate technology in powder metallurgy. - Abstract: Successful microwave sintering of several metal powders had been reported by many researchers with remarkable improvements in the materials properties and/or in the overall process. However, the concept behind microwave heating of metal powders has not been fully understood till now, as it is well known that bulk metals reflect microwaves. The progress of microwave sintering of copper metal powder compacts was investigated via combining both in-situ electrical resistivity and dilatometry measurements that give important information about microstructural changes with respect to the inter-particle electrical contacts during sintering. The sintering behavior of copper metal powders was depending on the type of the gas used, particle size, the initial green density, the soaking sintering time and the thin oxide layer on the particles surfaces. The thin copper oxide native layer (ceramics) that thermodynamically formed on the particles surfaces under normal handling and ambient environmental conditions had a very critical and important role in the microwave absorption and interaction, the sintering behavior and the microstructural changes. This finding could help to have a fundamental understanding of why MW’s interact with copper metal powder in a different way than its bulk at room temperature, i.e. why a given metal powder could be heated using microwaves while its bulk reflects it

  2. Use of Amino‐Functionalized CNTs and CVD Grown CNTs for Better Dispersion in Al Powder in the Fabrication of Composites

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, S. K.; Mathur, R. B. [National Physical Laboratory (CSIR), New Delhi‐1100 12 (India); Mamta,; Teotia, Satish [Guru Jambheshwar University of Science and Technology, Hisar (India); Chahal, Rajiv [Nanoscience and Nanotechnology, Panjab University, Chandigarh (India)

    2011-12-12

    We report an improved process for the better dispersion of multiwalled carbon nanotubes (MWCNTs) in Al powder used for the fabrication of Al‐matrix composites employing powder metallurgy process. For obtaining a better dispersion of MWCNTs in Al, we used two types of MWCNTs. In the first type, the MWCNTs were firstly functionalized by using ammonium bi‐carbonate and mix with Al powder using a high energy ball mill in the presence of a process control agent. In the second type we grew MWCNTs directly on Al powder using CVD. Various mechanical properties of the composites including micro hardness, compressive strength etc. were determined. It has been observed that using functionalized MWCNTs (fCNTs) and CVD grown MWCNTs, these properties were found to enhance significantly. The dispersion of functionalized CNTs was studied by SEM and the interfacial bonding between functionalized CNTs and Al matrix using high resolution transmission electron microscopy (HRTEM).

  3. Hydrothermal metallurgy for recycling of slag and glass

    International Nuclear Information System (INIS)

    Tanaka, Toshihiro; Yoshikawa, Takeshi; Hirai, Nobumitsu; Katsuyama, Shigeru

    2009-01-01

    The authors have applied hydrothermal reactions to develop recycling processing of slag or glass. As an example, under hydrothermal conditions such as 200 300 deg. C and 30 40MPa with H 2 O, powders made of glass can be sintered to become solidified glass materials containing about 10mass% H 2 O. When the glass containing H 2 O is heated again under normal pressure, the glass expands releasing H 2 O to make porous microstructure. H 2 O starts to emit just above the glass transition temperature. Therefore, when we have a glass with low glass transition temperature, we can make low temperature foaming glass. The SiO 2 -Na 2 O-B 2 O 3 glass is a candidate to be such a foaming glass. In this paper, we describe our recent trial on the fabrication of the low temperature foaming glass by using hydrothermal reaction.

  4. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  5. Laser cladding with powder

    NARCIS (Netherlands)

    Schneider, M.F.; Schneider, Marcel Fredrik

    1998-01-01

    This thesis is directed to laser cladding with powder and a CO2 laser as heat source. The laser beam intensity profile turned out to be an important pa6 Summary rameter in laser cladding. A numerical model was developed that allows the prediction of the surface temperature distribution that is

  6. Metals in Past Societies: A Global Perspective on Indigenous African Metallurgy Shadreck Chirikure

    Energy Technology Data Exchange (ETDEWEB)

    Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    This slim book (166 pages) shines a spotlight on pre-industrial African metallurgy, its global connections, and anthropological implications. It integrates seemingly disparate disciplines, such as history, geology, ethnography, archeology, and metallurgy, to illustrate the diversity and innovation in metallurgy across Africa and the role of metals in the rise of socio-economic inequalities and political power. The book has 7 chapters and the focus on metals as enablers of human needs and wants is evident in each chapter. The first chapter presents the context of the work and data sources. The second chapter focuses on the origin and development of mining and metallurgy in pre-industrial Africa. Chapter 3 is dedicated to the interaction of nature and culture in the process of mining. Chapter 4 deals with the transformation of the ore into metal by smelting and the sociocultural aspects of this process. Chapter 5 explores the social and cultural roles acquired by metals as a result of fabrication into objects. Chapter 6 examines the social role of metals, trade in metals, cultural contact, proto-globalization, and technology transfer. Finally, Chapter 7 draws lessons for global anthropology from the African experience. The sources of information are adequately cited and the long list of references at the end of each chapter will be a boon to researchers in this field. The author highlights the cultural aspects and social context of the adoption of metallurgy in Africa while drawing parallels between practices in pre-industrial Africa and those in other parts of the world. The book is peppered with delightful vignettes that offer insights into the process of transforming nature into culturally significant objects. For instance, African miners, like their counterparts in Nepal and Latin America, called upon deities, spirits and ancestors to mediate between nature and humans. Women had distinct roles in this process, but there were variations in these roles and in the

  7. List of unclassified documents by the staff of Metallurgy Division, AERE Harwell from January 1979 to July 1980

    International Nuclear Information System (INIS)

    Smith, N.C.

    1980-12-01

    This list constitutes unclassified material published or presented between January 1979 and July 1980, by the staff of Metallurgy Division. It covers reports, memoranda, articles in periodicals, conference papers, books and patent specifications. (author)

  8. Thermogravimetric control of intermediate compounds in uranium metallurgy; Control termogravimetrico de productos intermedios de la metalurgia del uranio

    Energy Technology Data Exchange (ETDEWEB)

    Gasco Sanchez, L.; Fernandez Cellini, R.

    1959-07-01

    The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs.

  9. Synthesis of Uranium nitride powders using metal uranium powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik

    2012-01-01

    Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N 15 gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work

  10. The effects of the addition of ferrite powder on magnetic properties of cold pressed Nd-Fe-B bonded magnets

    International Nuclear Information System (INIS)

    Rodrigues, D.; Landgraf, F.J.G.; Emura, M.

    1998-01-01

    This paper investigates the effects of strontium ferrite powder addition on magnetic properties of cold pressed isotropic NdFeB bonded magnets. Bonded magnets are polymer composites based on a mixture of a hard magnetic powder(s) and an organic component. This mixture can be processed as a traditional powder metallurgy material, i.e., cold pressed, or it can be processed like a thermoplastic material, i.e., by injection molding. The polymeric phase to a large extent determines the mechanical properties of this composite, while magnetic powder determines its magnetic properties. They are less expensive and easier to produce, especially in the case of high complexity parts. The mixture of ferrite and Nd-Fe-B to produce hybrid bonded magnets creates the possibility to produce magnets with properties and cost between Nd-Fe-B and ferrite magnets. The cold pressed NdFeB bonded magnets were manufactured here with melt spun flakes (MQPA) mixed with strontium ferrite powder and polyester resin. Eight different compositions, between 0 wt.% and 80 wt.% of ferrite, were investigated. The most important result analyzed was the shape of demagnetization curves and the values of coercivity and intrinsic coercivity. (orig.)

  11. Synthesis and characterization of carbon nanotubes over iron carbide nanoparticles coated Al powder using thermal chemical vapor deposition

    Science.gov (United States)

    Singhal, S. K.; Seth, R. K.; Rashmi; Teotia, Satish; Mamta; Chahal, Rajeev; Mathur, R. B.

    2013-02-01

    A simple method is described to synthesize carbon nanotubes (CNTs) by the thermal decomposition of toluene at 750°C over a thin catalyst film deposited on Al powder. This method allows the bulk metal surface to act as both the catalyst and support for CNT growth. The catalyst film on Al was prepared from an ethanol solution of iron nitrate. Under the growth conditions, iron nitrate formed an amorphous iron oxide layer that transform into crystalline Fe2O3, which was further reduced to Fe3O4 and Fe3C. It is believed that the growth of CNTs took place on iron carbide nanoparticles that were formed from FeO. The characterization of CNTs was mainly carried out by powder X-ray diffraction and scanning electron microscopy, X-ray fluorescence and thermogravimatric analysis. The CNTs were found to be highly dispersed in Al powder. This composite powder could be further used for the fabrication of Al matrix composites using powder metallurgy process in which the powder were first cold pressed at 500-550 MPa followed by sintering at 620°C for 2 h under a vacuum of 10-2 torr. The mechanical properties of the sintered composites were measured using a microhardness tester and a Universal testing Instron machine.

  12. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  13. [Investigation about prevention behavior for dust workers in machinery, ceramic, and metallurgy industry].

    Science.gov (United States)

    Shen, Fu-hai; Ma, Qing-kun; Xiao, Shu-yu; Cui, Feng-tao; Meng, Qing-di; Yang, Xiu-qing; Qi, Hui-sheng; Fan, Xue-yun; Yao, San-qiao

    2011-01-01

    The purposes of this thesis were to study the behavior about workers exposed to dust and provide scientific basis for health promotion. We designed a questionnaire and carry it on the 746 dust workers in the 3 representative corporations of Machinery, Ceramic, and Metallurgy Industry. All data were input into computer. And a database was established with Excel. SPSS11.5 statistical analysis software was used to analyze the influence on protecting behavioral between the application of qualifications, different jobs, training or protection, and other aspects etc. The rates were 94.4% and 75.3% about the regular physical examination and requirements for protective equipment. The rate of choosing an effective way of protection was generally low (15.4%). There was significant difference for among different educational background workers (P Metallurgy Industry. Those who were not educated had a lower using rate about the protection behavior, regular physical examination, and requirements for protective equipment than those educated.

  14. [Risk and features of occupational diseases in nonferrous metallurgy workers of Kolsky Transpolar area].

    Science.gov (United States)

    Siurin, S A; Chashchin, V P; Frolova, N M

    2015-01-01

    The study covered data on 977 cases of occupational diseases in 615 workers of nonferrous metallurgy in Kolsky Transpolar area. Findings are high risk of occupational diseases in workers engaged into electrolysis production of aluminium, all nickel reprocessing and pyrometallic copper reprocessing (GR 7.02-10.0). Electrolysis operators and anode operators of aluminium production are more prone to occupational diseases, with bone and muscular disorders (46.8%) prevalent in the morbidity structure. Respiratory diseases are more prevalent (68.2-100%) in the occupational morbidity structure of copper-nickelindustry workers. Conclusion is made on mandatory improvement of the work conditions and more effective individual protective means against occupational hazards in workers of nonferrous metallurgy in Kolsky Transpolar area.

  15. Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

    Science.gov (United States)

    Nie, Zhiqiang; Yang, Yufei; Tang, Zhenwu; Liu, Feng; Wang, Qi; Huang, Qifei

    2014-11-01

    Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

  16. Compressive Deformation Behavior of Open-Cell Cu-Zn-Al Alloy Foam Made Through P/M Route Using Mechanically Alloyed Powder

    Science.gov (United States)

    Barnwal, Ajay Kumar; Mondal, D. P.; Kumar, Rajeev; Prasanth, N.; Dasgupta, R.

    2018-02-01

    Cu-Zn-Al foams of varying porosity fractions using mechanical alloyed powder have been made through powder metallurgy route. Here, NH4 (HCO3) was used as a space holder. Mechanically alloyed Cu-Zn-Al is made using a planetary ball mill taking the ratio of Cu/Zn/Al = 70:25:5 (by weight ratio). The ball/powder ratios were varied in the four ranges 10:1, 15:1, 20:1, and 25:1. Green compacts of milled powder and space holder samples were sintered at three stages at three different temperatures 350, 550, and 850 °C for 1 h at each stage. The crystalline size and particle size as a function of ball/powder ratios were examined. The compressive deformation responses of foams are varied with relative density and the ball/powder ratio. The plateau stress and energy absorption of these foams increase with an increase in relative density but decreases with increase in ball/powder ratio, even though crystalline size decreases. This has further been explained on the basis of particle morphology as a function of ball/powder ratio.

  17. Metallurgy Department. Progress Report for the Period 1 January to 31 December 1984

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The activities of the Metallurgy Department at Risø during 1984 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its...... activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1984 is included....

  18. Metallurgy Department progress report for the period 1 January to 31 December 1986

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

    1987-04-01

    The activities of the Metallurgy Department at Risoe during 1986 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Chemical and Electrochemical Energy Research and Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1986 is included. (editors)

  19. Metallurgy department progress report for the period 1 January to 31 December 1977

    International Nuclear Information System (INIS)

    1978-03-01

    The activities of the Metallurgy Department at Risoe during 1977 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel elements, and Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1977 is included. (author)

  20. Metallurgy Department progress report for the period 1 January to 31 December 1985

    International Nuclear Information System (INIS)

    Schroeder Pedersen, A.; Bilde Soerensen, J.B.

    1986-04-01

    The activities of the Metallurgy department at Risoe during 1985 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Chemical and Electrochemical Energy Research and Development, and Fuel elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1985 is included. (author)

  1. Metallurgy department progress report for the period 1 January to 31 December 1980

    International Nuclear Information System (INIS)

    1981-07-01

    The activities of the Metallurgy Department at Risoe during 1980 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel Elements, Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1980 is included. (Author)

  2. Situation of radioactive wastes and their prevention and treatment measures in China's uranium mining and metallurgy

    International Nuclear Information System (INIS)

    Li Renjie.

    1988-01-01

    The sorts of radioactive wastes produced in uranium mining and metallurgy and their hazards are discribed in this paper. The characteristics of the radioactive wastes are discussed. The measurements and results are introduced for treatment and disposal of the radioactive wastes. The way to deal with prevention and treatment of radioactive wastes is presented in the stages of engineering design, construction, production and decommission of uranium mines and plants

  3. Extractive metallurgy of the beryllium; Fundamentos da metalurgia extrativa do berilio

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Neusa; Capocchi, Jose Deodoro Trani [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    1995-07-01

    A bibliographic review is performed on the beryllium extractive metallurgy. The work describes the main type of ores and processes applied to the metallic beryllium production, beryllium oxide production using fluoride, sulfide and direct chlorination. The thermodynamic consideration are made on beryllium reduction processes, discussing the viability of the beryllium oxide and hallide reduction processes. Under the technological viewpoint, the Cu-Be alloys main production processes are discussed, and the main toxicity problems related with beryllium are mentioned 15 refs..

  4. Metallurgy department progress report for the period 1 January to 31 December 1978

    International Nuclear Information System (INIS)

    1979-04-01

    The activities of the metallurgy department at Risoe during 1978 are described. The work is presented in four chapters: General materials research, technology and materials development, fuel elements, and non-destructive testing. Furthermore, a survey is given of the depratment's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1978 is included. (author)

  5. Metallurgy department progress report for the period 1 January to 31 December 1983

    International Nuclear Information System (INIS)

    1984-06-01

    The activities of the Metallurgy Department at Risoe during 1983 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. Furthermore, a survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1983 is included. (author)

  6. Powder Processing of High Temperature Cermets and Carbides at Marshall Space Flight Center

    Science.gov (United States)

    Salvail, Pat; Panda, Binayak; Hickman, Robert R.

    2007-01-01

    The Materials and Processing Laboratory at NASA Marshall Space Flight Center is developing Powder Metallurgy (PM) processing techniques for high temperature cermet and carbide material consolidation. These new group of materials would be utilized in the nuclear core for Nuclear Thermal Rockets (NTR). Cermet materials offer several advantages for NTR such as retention of fission products and fuels, better thermal shock resistance, hydrogen compatibility, high thermal conductivity, and high strength. Carbide materials offer the highest operating temperatures but are sensitive to thermal stresses and are difficult to process. To support the effort, a new facility has been setup to process refractory metal, ceramic, carbides and depleted uranium-based powders. The facility inciudes inert atmosphere glove boxes for the handling of reactive powders, a high temperature furnace, and powder processing equipment used for blending, milling, and sieving. The effort is focused on basic research to identify the most promising compositions and processing techniques. Several PM processing methods including Cold and Hot Isostatic Pressing are being evaluated to fabricate samples for characterization and hot hydrogen testing.

  7. Titanium Powder Sintering in a Graphite Furnace and Mechanical Properties of Sintered Parts

    Directory of Open Access Journals (Sweden)

    Changzhou Yu

    2017-02-01

    Full Text Available Recent accreditation of titanium powder products for commercial aircraft applications marks a milestone in titanium powder metallurgy. Currently, powder metallurgical titanium production primarily relies on vacuum sintering. This work reported on the feasibility of powder sintering in a non-vacuum furnace and the tensile properties of the as-sintered Ti. Specifically, we investigated atmospheric sintering of commercially pure (C.P. titanium in a graphite furnace backfilled with argon and studied the effects of common contaminants (C, O, N on sintering densification of titanium. It is found that on the surface of the as-sintered titanium, a severely contaminated porous scale was formed and identified as titanium oxycarbonitride. Despite the porous surface, the sintered density in the sample interiors increased with increasing sintering temperature and holding time. Tensile specimens cut from different positions within a large sintered cylinder reveal different tensile properties, strongly dependent on the impurity level mainly carbon and oxygen. Depending on where the specimen is taken from the sintered compact, ultimate tensile strength varied from 300 to 580 MPa. An average tensile elongation of 5% to 7% was observed. Largely depending on the interstitial contents, the fracture modes from typical brittle intergranular fracture to typical ductile fracture.

  8. The evaluation of microstructure and mechanical properties of sintered sub-micron WC-Co powders

    International Nuclear Information System (INIS)

    Nor Izan Izura; Mohd Asri Selamat; Noraizham Mohamad Diah; Talib Ria Jaafar

    2007-01-01

    A cemented tungsten carbide (WC-Co) is widely used for a variety of machining, cutting, drilling and other applications. The properties of this tungsten heavy alloy are sensitive to processing and degraded by residual porosity. The sequence of high end powder metallurgy process include mixing, compacting and followed by multi-atmosphere sintering of green compact were analyzed. The sub micron (<1.0 μm) and less than 10.0 μm of WC powders are sintered with a metal binder 6% Co to provide pore-free part. The powder compacts were sintered at temperatures cycle in the range of 1200 degree Celsius-1550 degree Celsius in nitrogen-based sintering atmosphere. To date, however there have been few reported studies in the literature that the best sintering was carried out via liquid phase sintering in vacuum at approximately 1500 degree Celsius. from this study we found that in order to attain high mechanical properties, a fine grain size of powder is necessary. Therefore, the attention of this work is to develop and produce wear resistant component with better properties or comparable to the commercial ones. (author)

  9. A millennium of metallurgy recorded by lake sediments from Morococha, Peruvian Andes.

    Science.gov (United States)

    Cooke, Colin A; Abbott, Mark B; Wolfe, Alexander P; Kittleson, John L

    2007-05-15

    To date, information concerning pre-Colonial metallurgy in South America has largely been limited to the archaeological record of artifacts. Here, we reconstruct a millennium of smelting activity in the Peruvian Andes using the lake-sediment stratigraphy of atmospherically derived metals (Pb, Zn, Cu, Ag, Sb, Bi, and Ti) and lead isotopic ratios (206Pb/ 207Pb) associated with smelting from the Morococha mining region in the central Peruvian Andes. The earliest evidence for metallurgy occurs ca. 1000 A.D., coinciding with the fall of the Wari Empire and decentralization of local populations. Smelting during this interval appears to have been aimed at copper and copper alloys, because of large increases in Zn and Cu relative to Pb. A subsequent switch to silver metallurgy under Inca control (ca. 1450 to conquest, 1533 A.D.) is indicated by increases in Pb, Sb, and Bi, a conclusion supported by further increases of these metals during Colonial mining, which targeted silver extraction. Rapid development of the central Andes during the 20th century raised metal burdens by an order of magnitude above previous levels. Our results represent the first evidence for pre-Colonial smelting in the central Peruvian Andes, and corroborate the sensitivity of lake sediments to pre-Colonial metallurgical activity suggested by earlier findings from Bolivia.

  10. Thermal analysis and evolution of shape loss phenomena during polymer burnout in powder metal processing

    Science.gov (United States)

    Enneti, Ravi Kumar

    2005-07-01

    Powder metallurgy technology involves manufacturing of net shape or near net shape components starting from metal powders. Polymers are used to provide lubrication during shaping and handling strength to the shaped component. After shaping, the polymers are removed from the shaped components by providing thermal energy to burnout the polymers. Polymer burnout is one of the most critical step in powder metal processing. Improper design of the polymer burnout cycle will result in formation of defects, shape loss, or carbon contamination of the components. The effect of metal particles on polymer burnout and shape loss were addressed in the present research. The study addressing the effect of metal powders on polymer burnout was based on the hypothesis that metal powders act to catalyze polymer burnout. Thermogravimetric analysis (TGA) on pure polymer, ethylene vinyl acetate (EVA), and on admixed powders of 316L stainless steel and 1 wt. % EVA were carried out to verify the hypothesis. The effect of metal powders additions was studied by monitoring the onset temperature for polymer degradation and the temperature at which maximum rate of weight loss occurred from the TGA data. The catalytic behavior of the powders was verified by varying the particle size and shape of the 316L stainless powder. The addition of metal particles lowered the polymer burnout temperatures. The onset temperature for burnout was found to be sensitive to the surface area of the metal particle as well as the polymer distribution. Powders with low surface area and uniform distribution of polymer showed a lower burnout temperature. The evolution of shape loss during polymer burnout was based on the hypothesis that shape loss occurs during the softening of the polymer and depends on the sequence of chemical bonding in the polymer during burnout. In situ observation of shape loss was carried out on thin beams compacted from admixed powders of 316L stainless steel and 1 wt. % ethylene vinyl acetate

  11. Diffraction. Powder, amorphous, liquid

    International Nuclear Information System (INIS)

    Sosnowska, I.M.

    1999-01-01

    Neutron powder diffraction is a unique tool to observe all possible diffraction effects appearing in crystal. High-resolution neutron diffractometers have to be used in this study. Analysis of the magnetic structure of polycrystalline materials requires the use of high-resolution neutron diffraction in the range of large interplanar distances. As distinguished from the double axis diffractometers (DAS), which show high resolution only at small interplanar distances, TOF (time-of-flight) diffractometry offers the best resolution at large interplanar distances. (K.A.)

  12. Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

    OpenAIRE

    Quy Bau Nguyen; Mui Ling Sharon Nai; Zhiguang Zhu; Chen-Nan Sun; Jun Wei; Wei Zhou

    2017-01-01

    In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing (AM) were studied using different powder characterization techniques. The results revealed that the particle size distribution (PSD) for the selective laser melting (SLM) process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·(50 g)−1. In addition, the packing density was found to be 60%. The rheological test re...

  13. Effects of long-time elevated temperature exposures on hot-isostatically-pressed power-metallurgy Udimet 700 alloys with reduced cobalt contents

    Science.gov (United States)

    Hart, F. H.

    1984-01-01

    Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides.

  14. Parametric Powder Diffraction

    Science.gov (United States)

    David, William I. F.; Evans, John S. O.

    The rapidity with which powder diffraction data may be collected, not only at neutron and X-ray synchrotron facilities but also in the laboratory, means that the collection of a single diffraction pattern is now the exception rather than the rule. Many experiments involve the collection of hundreds and perhaps many thousands of datasets where a parameter such as temperature or pressure is varied or where time is the variable and life-cycle, synthesis or decomposition processes are monitored or three-dimensional space is scanned and the three-dimensional internal structure of an object is elucidated. In this paper, the origins of parametric diffraction are discussed and the techniques and challenges of parametric powder diffraction analysis are presented. The first parametric measurements were performed around 50 years ago with the development of a modified Guinier camera but it was the automation afforded by neutron diffraction combined with increases in computer speed and memory that established parametric diffraction on a strong footing initially at the ILL, Grenoble in France. The theoretical parameterisation of quantities such as lattice constants and atomic displacement parameters will be discussed and selected examples of parametric diffraction over the past 20 years will be reviewed that highlight the power of the technique.

  15. Discrete element modeling of powder consolidation and the formation of titanium-matrix composites from powder-fiber monotapes

    Science.gov (United States)

    Newell, Kenneth James

    A three year research effort is completed with the development of the Discrete Element Consolidation Analyzer (DECA) for process modeling the formation of titanium composites from powder-fiber monotapes. The primary goal of the DECA process model is to provide a statistically realistic analysis of the various physical processes necessary to achieve higher quality composites from the powder-fiber technique. Over the course of this effort, research and code development was conducted in three distinct stages. The first stage focused on the simulation of initial geometry of the powder and fibers as well as the evolution of tape configuration during the pre-consolidation processing steps. The second stage developed the mechanics of the discrete element powder consolidation and the material characterization methods necessary to model the viscoplastic response of the powder to transient thermal and mechanical boundary conditions. The final stage incorporated the presence of fibers to evaluate the interaction mechanics and possible fibers damage resulting from discrete powder-fiber contacts. As a conclusion to the research, DECA model predictions of density versus time for various consolidation profiles are directly compared to actual consolidation test results and a DECA prescribed process profile is used to fabricate a 6sp{''} × 6sp{''} composite panel of Ti-6242/SCS-6. In completing this research, the discrete element modeling technique has proven to be a powerful tool for the analysis and simulation of metal powder consolidation as well as the consolidation of metal matrix composites. The DECA code orchestrates the use of particle kinetics, some simple aspects of gas dynamics, elasticity, plasticity, creep and various innovative material characterization methods to produce a seamless analysis for powder metallurgy processing of composites. Through the application of the DECA capability, many aspects of the processing stages have been elucidated for further

  16. Consolidation of copper and aluminium powders by spark plasma sintering

    Science.gov (United States)

    Saiprasad, M.; Atchayakumar, R.; Thiruppathi, K.; Raghuraman, S.

    2016-09-01

    Processing in the powder metallurgy route has emerged as an economical process for the production of near net shaped components with a wide range of desired mechanical properties suitable for various applications of industrial needs. This research work was conducted with an objective of studying the improvisation of density and hardness of Copper-Aluminium alloy prepared by spark plasma sintering. Cu-Al alloy with a composition of 95% copper and 5% aluminium was prepared by SPS process. SPS is a low voltage, DC pulse current activated, pressure-assisted sintering, which enables sintering at lower temperatures and shorter durations. The combination offered by Cu-Al alloy of high strength and high corrosion resistance results their applications under a wide variety of conditions. The density and hardness of the prepared sample were measured by conducting appropriate tests. Apparently, the values of hardness and density of the specimen prepared by SPS seemed to be better than that of conventional sintering. The experimental procedure, testing methodologies and analysis are presented.

  17. Nuclear fuel powder transfer device

    International Nuclear Information System (INIS)

    Komono, Akira

    1998-01-01

    A pair of parallel rails are laid between a receiving portion to a molding portion of a nuclear fuel powder transfer device. The rails are disposed to the upper portion of a plurality of parallel support columns at the same height. A powder container is disposed while being tilted in the inside of the vessel main body of a transfer device, and rotational shafts equipped with wheels are secured to right and left external walls. A nuclear powder to be mixed, together with additives, is supplied to the powder container of the transfer device. The transfer device engaged with the rails on the receiving side is transferred toward the molding portion. The wheels are rotated along the rails, and the rotational shafts, the vessel main body and the powder container are rotated. The nuclear powder in the tilted powder container disposed is rotated right and left and up and down by the rotation, and the powder is mixed satisfactory when it reaches the molding portion. (I.N.)

  18. Functional dependency between the logistics security system and the MySAP ERP in metallurgy

    Directory of Open Access Journals (Sweden)

    P. Ranitović

    2013-10-01

    Full Text Available MySAP ERP - Enterprise Resource Planning (system - solution which provides a whole set of functions for the business analytics, finance, human resources management, logistics and corporate services has developed from SAP R/3. It is one of the main products of the SAP AG German multinational company and as such, it is a very important element of the international industrial and technological security system. By defining the functional dependency between the security systems (logistics security systems and the IT (My SAP ERP systems in metallurgy, a concept for designing MY SAP ERP system in metallurgic industry is defined, based on the security aspects.

  19. Physical metallurgy: Scientific school of the Academician V.M. Schastlivtsev

    Science.gov (United States)

    Tabatchikova, T. I.

    2016-04-01

    This paper is to honor Academician Vadim Mikhailovich Schastlivtsev, a prominent scientist in the field of metal physics and materials science. The article comprises an analysis of the topical issues of the physical metallurgy of the early 21st century and of the contribution of V.M. Schastlivtsev and of his school to the science of phase and structural transformations in steels. In 2015, Vadim Mikhailovich celebrates his 80th birthday, and this paper is timed to this honorable date. The list of his main publications is given in it.

  20. Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces

    International Nuclear Information System (INIS)

    Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

    2014-01-01

    This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

  1. Proceedings of the III International Congress of Mining and Metallurgy MINEMETAL 2016

    International Nuclear Information System (INIS)

    2016-10-01

    The III International Congress of Mining and Metallurgy was inaugurated at the Plaza América Convention Center in Varadero. Professionals from 16 countries come together to promote scientific exchange for sustainable mining and to make concrete future investments to boost the development of this important sector in Cuba. Among the topics that will occupy the agenda of these days of congress stand out the development of geology, new technological processes, advances in the application of zeolite, sustainable development and care of the environment.

  2. Metallurgy department progress report for the period 1 January to 31 December 1979

    International Nuclear Information System (INIS)

    1980-07-01

    The activities of the Metallurgy Department at Risoe during 1979 are described. The work is presented in four chapters: General material research, technology and materials development, fuel elements, non-destructive testing. An article on wingblades of glass fibre reinforced polyester for a 630 kW windturbine is also included. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1979 is included. (author)

  3. Unique opportunities in powder injection molding of refractory and hard materials

    International Nuclear Information System (INIS)

    German, R.M.

    2001-01-01

    Powder injection molding (PIM) is a relatively new manufacturing process for the creation of complicated net-shapes outside the range usually possible via powder metallurgy technologies. This new process is now in production at more than 550 sites around the world. Although a small industry, PIM will soon pass $1 billion dollars (USA) in annual sales. This presentation overviews the PIM process, some of the new developments and some of the successes that have occurred with both refractory metals and hard metals. Example applications are seen in medical and dental devices, industrial components, wristwatches, jet engines, firearms, automotive components, and even hand tools. To help establish the novel growth opportunities, PIM is compared to other fabrication routes to better understand the design features arising with this new approach, providing a compelling case for substantial opportunities in the refractory and hard materials. Illustrations are provided of several components in production. New opportunities abound for the technology, since it eliminates the shape complexity barrier associated with die compaction and the cost of machining associated with complicated or dimensionally precise components. Further, a relative cost advantage exists for refractory and hard materials because PIM can use the same powders at the same prices as employed in alternative processes. Future successes will occur by early identification of candidate materials and designs. Early examples include tungsten heavy alloy components now reaching production rates of six million per month. (author)

  4. Preparation of superconductor precursor powders

    Science.gov (United States)

    Bhattacharya, Raghunath; Blaugher, Richard D.

    1995-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  5. (TECTONA GRANDIS LEAF POWDER

    Directory of Open Access Journals (Sweden)

    Yash Mishra

    2015-01-01

    Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

  6. Summary of NRC LWR safety research programs on fuel behavior, metallurgy/materials and operational safety

    International Nuclear Information System (INIS)

    Bennett, G.L.

    1979-09-01

    The NRC light-water reactor safety-research program is part of the NRC regulatory program for ensuring the safety of nuclear power plants. This paper summarizes the results of NRC-sponsored research into fuel behavior, metallurgy and materials, and operational safety. The fuel behavior research program provides a detailed understanding of the response of nuclear fuel assemblies to postulated off-normal or accident conditions. Fuel behavior research includes studies of basic fuel rod properties, in-reactor tests, computer code development, fission product release and fuel meltdown. The metallurgy and materials research program provides independent confirmation of the safe design of reactor vessels and piping. This program includes studies on fracture mechanics, irradiation embrittlement, stress corrosion, crack growth, and nondestructive examination. The operational safety research provides direct assistance to NRC officials concerned with the operational and operational-safety aspects of nuclear power plants. The topics currently being addressed include qualification testing evaluation, fire protection, human factors, and noise diagnostics

  7. Analysis of cancer mortality risk among workers of a research uranium metallurgy division in France

    International Nuclear Information System (INIS)

    Jejati, H.; Laurier, D.; Tirmarche, M.; Giraud, J.M.

    1997-01-01

    This cohort study has been undertaken in response to a suspected cluster of cancers mentioned by workers involved in research activities concerning the metallurgy of uranium. The studied population included all persons having worked between 1950 and 1968 at the Metallurgy Division of the French Atomic Energy Commission (CEA). Exposures were registered on an individual annual basis. For analysis, they were grouped in three categories: use of chemicals agents (Benzene, beryllium, alcohols, solvents ...), manipulation of radioactive materials (uranium, thorium, fission decay products), and exposure to external radiation. This relatively small cohort included 356 workers followed up to December 1990. Out of observed deaths, 21 were from cancer. Total mortality from cancer was less than expected from national rates (Standardised Mortality Ratio = 0.73). Cancer mortality did not increase with duration of exposure to external radiation or with duration of manipulation of radioactive materials. Risk of cancer was increasing with the number of years of exposure to chemicals. The small size of this cohort limits the conclusion of the observed results. The purpose, despite this lack of power, was to answer a worry of the workers, more than to estimate a clear dose-response relationship linked to a specific cancer site. The effect studied here is ''all cancers'', a distinction of the different sites being uninformative because of the very small number of cases observed. Nevertheless, this study suggests some routes for further research: it highlights the importance of considering concomitant exposures like chemical ones in studies of nuclear workers. (author)

  8. Metallurgy of high-silicon steel parts produced using Selective Laser Melting

    International Nuclear Information System (INIS)

    Garibaldi, Michele; Ashcroft, Ian; Simonelli, Marco; Hague, Richard

    2016-01-01

    The metallurgy of high-silicon steel (6.9%wt.Si) processed using Selective Laser Melting (SLM) is presented for the first time in this study. High-silicon steel has great potential as a soft magnetic alloy, but its employment has been limited due to its poor workability. The effect of SLM-processing on the metallurgy of the alloy is investigated in this work using microscopy, X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). XRD analysis suggests that the SLM high-silicon steel is a single ferritic phase (solid solution), with no sign of phase ordering. This is expected to have beneficial effects on the material properties, since ordering has been shown to make silicon steels more brittle and electrically conductive. For near-fully dense samples, columnar grains with a high aspect ratio and oriented along the build direction are found. Most importantly, a <001> fibre-texture along the build direction can be changed into a cube-texture when the qualitative shape of the melt-pool is altered (from shallow to deep) by increasing the energy input of the scanning laser. This feature could potentially open the path to the manufacture of three-dimensional grain-oriented high-silicon steels for electromechanical applications.

  9. Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

    Science.gov (United States)

    Hillman, Aubrey L; Abbott, Mark B; Yu, JunQing; Bain, Daniel J; Chiou-Peng, TzeHuey

    2015-03-17

    Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

  10. Fractionation study in bioleached metallurgy wastes using six-step sequential extraction.

    Science.gov (United States)

    Krasnodebska-Ostrega, Beata; Pałdyna, Joanna; Kowalska, Joanna; Jedynak, Łukasz; Golimowski, Jerzy

    2009-08-15

    The stored metallurgy wastes contain residues from ore processing operations that are characterized by relatively high concentrations of heavy metals. The bioleaching process makes use of bacteria to recover elements from industrial wastes and to decrease potential risk of environmental contamination. Wastes were treated by solutions containing bacteria. In this work, the optimized six-stage sequential extraction procedure was applied for the fractionation of Ni, Cr, Fe, Mn, Cu and Zn in iron-nickel metallurgy wastes deposited in Southern Poland (Szklary). Fractionation and total concentrations of elements in wastes before and after various bioleaching treatments were studied. Analyses of the extracts were performed by ICP-MS and FAAS. To achieve the most effective bioleaching of Zn, Cr, Ni, Cu, Mn, Fe the usage of both autotrophic and heterotrophic bacteria in sequence, combined with flushing of the residue after bioleaching is required. 80-100% of total metal concentrations were mobilized after the proposed treatment. Wastes treated according to this procedure could be deposited without any risk of environmental contamination and additionally the metals could be recovered for industrial purposes.

  11. Neutron Powder Diffraction in Sweden

    International Nuclear Information System (INIS)

    Tellgren, R.

    1986-01-01

    Neutron powder diffraction in Sweden has developed around the research reactor R2 in Studsvik. The article describes this facility and presents a historical review of research results obtained. It also gives some ideas of plans for future development

  12. Rotary powder feed through apparatus

    Science.gov (United States)

    Lewis, Gary K.; Less, Richard M.

    2001-01-01

    A device for increasing the uniformity of solids within a solids fabrication system, such as a direct light fabrication (DLF) system in which gas entrained powders are passed through the focal point of a moving high-power light which fuses the particles in the powder to a surface being built up in layers. The invention provides a feed through interface wherein gas entrained powders input from stationary input lines are coupled to a rotating head of the fabrication system. The invention eliminates the need to provide additional slack in the feed lines to accommodate head rotation, and therefore reduces feed line bending movements which induce non-uniform feeding of gas entrained powder to a rotating head.

  13. Phonons from neutron powder diffraction

    Science.gov (United States)

    Dimitrov, D. A.; Louca, D.; Röder, H.

    1999-09-01

    The spherically averaged structure function S(\\|q\\|) obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of S(\\|q\\|) to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e., it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center (\\|q\\|≠0) phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure [dynamics from powder diffraction] has been successfully implemented as demonstrated here for two systems, a simple metal fcc Ni and an ionic crystal CaF2. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from neutron powder diffraction.

  14. Dry and coating of powders

    International Nuclear Information System (INIS)

    Alonso, M.; Alguacil, F. J.

    1999-01-01

    This paper presents a review on the mixing and coating of powders by dry processes. The reviews surveys fundamental works on mixture characterization (mixing index definitions and sampling techniques), mixing mechanisms and models, segregation with especial emphasis on free-surface segregation, mixing of cohesive powders and interparticle forces, ordered mixing (dry coating) including mechanism, model and applications and mixing equipment selection. (Author) 180 refs

  15. Self-Paced Tutorial Courses for Mineral Science - Metallurgy Departments. Final Progress Report (July 1975-August 1980).

    Science.gov (United States)

    Twidwell, L. G.

    Four courses in extractive metallurgy (Pyrometallurgy, Hydrometallurgy, Electrometallurgy; and Physical Chemistry of Iron and Steel) were prepared in a modular, self-paced format. Development of the course materials included: (1) preparation of course outlines by unit coordinators and advisory committees; (2) approval of course outlines (included…

  16. Powder collection apparatus/method

    Science.gov (United States)

    Anderson, I.E.; Terpstra, R.L.; Moore, J.A.

    1994-01-11

    Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle of the housing interior wall measured from the same horizontal plane so as to direct the gas stream into the expansion chamber generally tangent to the housing interior wall to establish a downward swirling gas stream flow in the expansion chamber. A powder collection container is communicated to the outlet of the expansion chamber to collect the powder for further processing. 4 figures.

  17. Physical metallurgy

    International Nuclear Information System (INIS)

    Adda, Y.; Dupouy, J.M.; Philibert, J.; Quere, S.

    1979-01-01

    This manual deals with the following subjects: plastic deformation of pure metals, yield strength in pure metals, work hardening in pure metals, hardening of solid solutions, recovery, recrystallization, crystal growth, creep, rupture and fatigue properties, metal transformations [fr

  18. Physical metallurgy

    International Nuclear Information System (INIS)

    Adda, Y.; Dupouy, J.M.; Philibert, J.; Quere, Y.

    1976-01-01

    In this manual, the following topics are discussed: thermodynamics of solid solutions, phase diagrams, properties of dilute solid solutions, structure of solid solutions, thermodynamics of surfaces, perfect dislocations, partial dislocations and stacking faults, interfaces, point defects

  19. Physical metallurgy

    International Nuclear Information System (INIS)

    Adda, Y.; Dupouy, J.M.; Philibert, J.; Quere, Y.

    1976-01-01

    In this manual the following topics are reviewed: macroscopic thermodynamics, statistical mechanics, quantum mechanics, cristallography, elasticity and anelasticity, and plastic deformation of a homogeneous medium [fr

  20. Physical metallurgy

    International Nuclear Information System (INIS)

    Adda, Y.; Dupouy, J.M.; Philibert, J.; Quere, Y.

    1976-01-01

    In this manual, the following topics are discussed: atomic vibrations, lattice thermal properties, chemical bonds, free electron model, band theory, properties of actinides, rare earths and transition metals, transport phenomena, magnetic properties, properties of liquid metals and amorphous state alloys

  1. Practical Metallurgy

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Deganello, Davide

    2003-01-01

    This is the report regards the activities carried out during the practical metatllurgy course concerning material properties and structures and their testing & analysis methods. During the course several aspects of the materials have been considered and different techniques have been analyzed....

  2. Structure and shear in a cohesive powder

    NARCIS (Netherlands)

    Janssen, R.J.M.

    2001-01-01

    Handling of powders and granular materials is of great importance to industry. However, the knowledge of many powder related processes in industry is poor. In this work, the flow behaviour of powder has been investigated with an advanced tester: the Flexible Wall Biaxial Tester. Flow of powder

  3. On the Methods to Measure Powder Flow.

    Science.gov (United States)

    Tan, Geoffrey; Morton, David A V; Larson, Ian

    2015-01-01

    The flow of powders can often play a critical role in the manufacturing of pharmaceutical products. Many of these processes require good, consistent and predictable flow of powders to ensure continuous production of pharmaceutical dosages and to ensure their quality. Therefore, the flow of powders is of paramount importance to the pharmaceutical industry and thus the measuring and evaluating of powder flow is of utmost importance. At present, there are numerous methods in which the flow of powders can be measured. However, due to the complex and environment-dependent nature of powders, no one method exists that is capable of providing a complete picture of the behaviour of powders under dynamic conditions. Some of the most commonly applied methods to measure the flow of powders include: density indices, such as the Carr index and Hausner ratio, powder avalanching, the angle of repose (AOR), flow through an orifice, powder rheometry and shear cell testing.

  4. Development of a Reproducible Powder Characterization Method using a Powder Rheometer

    DEFF Research Database (Denmark)

    Søgaard, Søren Vinter; Allesø, Morten; Garnæs, Jørgen

    2012-01-01

    In this study, a powder rheometer was used to measure flow characteristics of two pharmaceutical model powders. Precise measurements were obtained for one of the model powders whereas the results were less precise for the second powder. In conclusion, further work is needed to increase...... the mechanistic understanding of powder rheological measurements....

  5. New evidence for prehistoric copper metallurgy in the vicinity of Bor

    Directory of Open Access Journals (Sweden)

    Kapuran Aleksandar

    2016-01-01

    Full Text Available The last three years of archaeological investigations at the site Ru`ana in Banjsko Polje, in the immediate vicinity of Bor, have provided new evidence regarding the role of non-ferrous metallurgy in the economy of the prehistoric communities of north-eastern Serbia. The remains of metallurgical furnaces and a large amount of metallic slags at two neighbouring sites in the mentioned settlement reveal that locations with many installations for the thermal processing of copper ore existed in the Bronze Age. We believe, judging by the finds of material culture, that metallurgical activities in this area also continued into the Iron Age and, possibly, into the 4th century AD. [Projekat Ministarstva nauke Republike Srbije, br. 177020: Archaeology of Serbia: Cultural identity, integration factors, technological processes and the role of the central Balkans in the development of European prehistory

  6. Annual report of the Metallurgy Division [for the] period ending December 1976

    International Nuclear Information System (INIS)

    Elayaperumal, K.; Gupta, C.K.; Mukhopadhyay, P.; Rao, S.V.K.

    1977-01-01

    An account of the work done in the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay, during the calendar year 1976 is given. Some of the major achievements are: (1) production of boron carbide and boral sheet for the Trombay R-5 reactor under construction, (2) production of niobium metal for the manufacture of Zr-Nb-Cu alloy garter springs, (3) development of a process for graphite coating on zircaloy, (4) studies on structural and metal physics aspects of zirconium alloys and steels, (5) studies on the corrosion behaviour of zircaloy-2 as affected by the replacement of helium and stress corrosion cracking of zircaloy fuel tubes in iodine atmosphere and (6) production of high density UO 2 pellets with stable microstructures and sinterable magnesium oxide for MHD application. (M.G.B.)

  7. Encyclopedic dictionary bilingual English-Spanish of sciences: mining, chemistry, geology, metallurgy and environment

    International Nuclear Information System (INIS)

    Munoz Maradona, M.; Bellini, M.; Busleiman, M.

    2007-01-01

    This dictionary has been designed to satisfy scientists, researchers, technicians, interpreters, translators and students' needs in the areas of chemistry, geology, mining, metallurgy and environment for they find it necessary to have an English- Spanish encyclopedia on their sciences. It is a reliable book when looking for words that are normally not included in everyday dictionaries. It is now reaching the final revision stage with more than 15,000 entries. It includes scientific terms, chemical formulas of minerals and other elements, noticeable scientists' biographies, tables, graphics, and images so as to help readers' understanding. It is divided into three columns: the first one presents the English term and its area of concern; the second, the corresponding Spanish equivalent, and in the third, a suitable explanation.(author)

  8. 9th Mining and metallurgy international congress, Leon, 24-28 May 1994

    International Nuclear Information System (INIS)

    1994-01-01

    The 9th Mining and Metallurgy International Congress had 201 communications. These was articulated into 4th areas: 1.- Geological resources management and profit: 1.1- Geological and mining research on geologic resources. 1.2.- Non energetic mineral resources exploitation. 1.3- Hydro-geologic and geothermia resources. 1.4- Geologic resources and planning. 2.- Energy: 2.1.- Energetic mining.- 2.2 Oil and gas. 2.3.- Electricity production and distribution. 2.4.- Coal clean technologies. 2.5.- Energetic management. 3.- Material engineering: 3.1.- Minerallurgia and metallurgic processes. 3.2- Industrial minerals and ornamental 10cks. 3.3 .- Building materials. 3.4 Advanced technology materials. 4.- Environmental and territorial engineering in basic industry. 4.1.-Valuation of environmental impacts. 4.2.- Restoration engineering in mining. 4.3.- Effluent and residue engineering. 4.4.- Environmental management and clean technologies 4.5.- Natural and technological risks

  9. [The organization of the comprehensive prevention of urolithiasis among ferrous metallurgy workers].

    Science.gov (United States)

    Egorova, A M

    2009-01-01

    The purpose of study is to evaluate the effectiveness of the set of preventive measures as applied to 321 workers of basic ferrous metallurgy specialties (steel makers, mill men, hot metal shearers). During the clinical examination all the workers were divided on three groups: the workers without any pathology (11.83%, the first group), the workers with metabolic disorders only without urolitiasis (64.81%, the second group) and the workers with urolitiasis diagnosis approved by ultrasonography (23.36%, the third group). The effectiveness of rehabilitation measures was evaluated during half a year (diet therapy, drinking regimen, medicinal plants treatment). After the course of preventive measures was applied the overall health condition of most workers ameliorated and the number of workers with urolitiasis development risk factors reliably decreased up to 6-12%.

  10. Separating and recycling metals from mixed metallic particles of crushed electronic wastes by vacuum metallurgy.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2009-09-15

    During the treatment of electronic wastes, a crushing process is usually used to strip metals from various base plates. Several methods have been applied to separate metals from nonmetals. However, mixed metallic particles obtained from these processes are still a mixture of various metals, including some toxic heavy metals such as lead and cadmium. With emphasis on recovering copper and other precious metals, there have hitherto been no satisfactory methods to recover these toxic metals. In this paper, the criterion of separating metals from mixed metallic particles by vacuum metallurgy is built. The results show that the metals with high vapor pressure have been almost recovered completely, leading to a considerable reduction of environmental pollution. In addition, the purity of copper in mixed particles has been improved from about 80 wt % to over 98 wt %.

  11. An Overview of Internal Fixation Implant Metallurgy and Galvanic Corrosion Effects.

    Science.gov (United States)

    Koh, Justin; Berger, Aaron; Benhaim, Prosper

    2015-08-01

    Orthopedic and hand surgery implants for internal fixation of fractures have evolved substantially over the past 50 years. Newer metal compositions have been used, and new standards have been applied to older alloys, resulting in modern implants with unique physical properties and better clinical performances. Conventional wisdom has long dictated that implanting different metals should be avoided, but few guidelines exist regarding the safety of using in proximity implant systems of dissimilar metals. To better characterize the landscape of internal fixation implant metallurgy, we have compiled the recommendations and conclusions of the currently available and pertinent literature. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  12. [Evaluation and prognosis of occupational risk in workers of nonferrous metallurgy enterprises].

    Science.gov (United States)

    Shliapnikov, D M; Kostarev, V G

    2014-01-01

    The article deals with results of a priori and a posteriori evaluation of occupational risk for workers' health. Categories of a priori occupational risk for workers are estimated as high to very high (intolerable) risk. Findings are that work conditions in nonferrous metallurgy workshop result in upper respiratory tract diseases (medium degree of occupational conditionality). Increased prevalence of such diseases among the workers is connected with length of service. The authors revealed priority factors for occupationally conditioned diseases. A promising approach in occupational medicine is creation of methods to evaluate and forecast occupational risk, that enable to specify goal parameters for prophylactic measures. For example, modelling the risk of occupationally conditioned diseases via changes in exposure to occupational factor and length of service proved that decrease of chemical concentrations in air of workplace to maximally allowable ones lowers risk of respiratory diseases from 14 to 6 cases per year, for length of service of 5 years and population risk.

  13. Structural behavior and microstructural hard metal sintered at 1350 deg C from the powder of nanometer WC with 10 wt% Co

    Energy Technology Data Exchange (ETDEWEB)

    Batista, A.C.; Perpetuo, G.J.; Leocadio, R.R.V., E-mail: adrianocorrea77@gmail.com [Rede Tematica de Engenharia de Materiais (REDEMAT), Ouro Preto, Minas Gerais (Brazil); Oliveira, H.C.P. de [Instituto Superior Tecnico (IST), Lisboa (Portugal). Departamento de Materiais

    2014-07-01

    The hard metal (WC-10%Co), processed via powder metallurgy, using powder of nanometer WC, were characterized from the point of view to the microstructural and structural techniques, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) for mapping and punctual. To analyze the behavior of hard metal after the sintering process performed in resistive furnace at 1350°C for 1 hour under vacuum of 10-2 mbar, the analysis identified the formation of WC grains, the pore distribution and behavior and evolution of the phases WC and Co, generating phases η (Co{sub 3}W{sub 3}C and Co{sub 6}W{sub 6}C). (author)

  14. Fabrication of metal matrix composite by semi-solid powder processing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yufeng [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Various metal matrix composites (MMCs) are widely used in the automotive, aerospace and electrical industries due to their capability and flexibility in improving the mechanical, thermal and electrical properties of a component. However, current manufacturing technologies may suffer from insufficient process stability and reliability and inadequate economic efficiency and may not be able to satisfy the increasing demands placed on MMCs. Semi-solid powder processing (SPP), a technology that combines traditional powder metallurgy and semi-solid forming methods, has potential to produce MMCs with low cost and high efficiency. In this work, the analytical study and experimental investigation of SPP on the fabrication of MMCs were explored. An analytical model was developed to understand the deformation mechanism of the powder compact in the semi-solid state. The densification behavior of the Al6061 and SiC powder mixtures was investigated with different liquid fractions and SiC volume fractions. The limits of SPP were analyzed in terms of reinforcement phase loading and its impact on the composite microstructure. To explore adoption of new materials, carbon nanotube (CNT) was investigated as a reinforcing material in aluminum matrix using SPP. The process was successfully modeled for the mono-phase powder (Al6061) compaction and the density and density distribution were predicted. The deformation mechanism at low and high liquid fractions was discussed. In addition, the compaction behavior of the ceramic-metal powder mixture was understood, and the SiC loading limit was identified by parametric study. For the fabrication of CNT reinforced Al6061 composite, the mechanical alloying of Al6061-CNT powders was first investigated. A mathematical model was developed to predict the CNT length change during the mechanical alloying process. The effects of mechanical alloying time and processing temperature during SPP were studied on the mechanical, microstructural and

  15. Effect of Sintering Atmosphere and Solution Treatment on Density, Microstructure and Tensile Properties of Duplex Stainless Steels Developed from Pre-alloyed Powders

    Science.gov (United States)

    Murali, Arun Prasad; Mahendran, Sudhahar; Ramajayam, Mariappan; Ganesan, Dharmalingam; Chinnaraj, Raj Kumar

    2017-10-01

    In this research, Powder Metallurgy (P/M) of Duplex Stainless Steels (DSS) of different compositions were prepared through pre-alloyed powders and elemental powders with and without addition of copper. The powder mix was developed by pot mill for 12 h to obtain the homogeneous mixture of pre-alloyed powder with elemental compositions. Cylindrical green compacts with the dimensions of 30 mm diameter and 12 mm height were compacted through universal testing machine at a pressure level of 560 ± 10 MPa. These green compacts were sintered at 1350 °C for 2 h in hydrogen and argon atmospheres. Some of the sintered stainless steel preforms were solution treated at 1050 °C followed by water quenching. The sintered as well as solution treated samples were analysed by metallography examination, Scanning Electron Microscopy and evaluation of mechanical properties. Ferrite content of sintered and solution treated DSS were measured by Fischer Ferritoscope. It is inferred that the hydrogen sintered DSS depicted better density (94% theoretical density) and tensile strength (695 MPa) than the argon sintered steels. Similarly the microstructure of solution treated DSS revealed existence of more volume of ferrite grains than its sintered condition. Solution treated hydrogen sintered DSS A (50 wt% 316L + 50 wt% 430L) exhibited higher tensile strength of 716 MPa and elongation of 17%, which are 10-13% increment than the sintered stainless steels.

  16. Net shape fabrication of stainless-steel micro machine components from metallic powder

    International Nuclear Information System (INIS)

    Imbaby, M; Jiang, K; Chang, I

    2008-01-01

    A fabrication process of the net shape 316-L stainless-steel micro machine components is reported. The fabrication process combines softlithography and powder metallurgy to produce microcomponents of complex geometries of high quality. The process starts with softlithography by producing ultra thick SU-8 master moulds and their negative replicas of polydimethylsiloxane (PDMS). Then stainless-steel slurry is prepared by mixing super fine 316-L steel powder and binder to fill the PDMS moulds. The two binders used in the experiments were Duramax D-3005 and a mixture of B1000 and B1007. The PDMS micro moulds are filled with the metallic slurries and green parts are obtained from de-moulding, before going through de-binding and sintering in forming gas atmosphere. The fabrication steps were repeatedly tested. The resultant micro parts show high quality shape retention which is attributed to the quality of the SU-8 master moulds. The hardness property of the sintered microcomponents was tested with a micro indenter and a 200 g load was applied. The Vickers hardness of the sintered components was found to be about 255, which was higher than 225 of annealed 316L stainless steel and the two binders make little difference on the hardness of the sintered samples

  17. Electrical conductivity and microstructure by Rietveld refinement of doped Cu-Ni powder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fambrini, A.S.; Monteiro, W.A.; Orrego, R.M.M.; Marques, I.M.; Carrio, Juan A.G., E-mail: jgcarrio@mackenzie.br, E-mail: iara_m_@hotmail.com [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica

    2009-07-01

    This work presents a comparative study of microstructural and electrical properties of polycrystalline material from two different Cu-Ni alloys: Cu-Ni-Pt and Cu-Ni-Al. The first one of them was produced in electric furnace with voltaic arc and the other was produced by powder metallurgy. The microstructure of the samples was studied by optical microscopy, Vickers micro hardness and x rays powder diffraction. Their electrical conductivity was measured with a milliohmmeter Agilent (HP) 4338B. Refinements of the crystalline structure of the samples were performed by the Rietveld method, using the refinement program GSAS. The refinement results and Fourier differences calculations indicate that the copper matrix structure presents not significant distortions by the used amounts of the other metal atoms. In both cases a sequence of thermo mechanical treatments was developed with the intention of increasing the hardness maintaining the electrical conductivity of the alloys. The refinements also allowed a study of the dependence of the micro-structure and the thermo mechanical treatments of the samples. (author)

  18. Structure and Properties of VT6 Alloy Obtained by Layered Selective Sintering of a Powder

    Science.gov (United States)

    Teresov, A. D.; Ivanov, Yu. F.; Petrikova, E. A.; Koval, N. N.

    2017-12-01

    This paper is focused on a clarification and analysis of the regularities of formation of the structure and properties of samples of the titanium-based alloy VT6, obtained by methods of conventional metallurgy and formed by layered selective electron-beam sintering in vacuum (using the Arcam A2X (3D printer) system (Arcam, Sweden)) of VT6 titanium powder with particle size 40-100 μm. Additional modification of the samples was realized by irradiating the surface with an intense pulsed electron beam (15 keV, 45 J/cm2, 200 μs, 10 pulses, 0.3 s-1, 3.5·10-2 Pa). It is shown that the action of a pulsed electron beam on the surface of samples formed by layered selective electron-beam sintering leads to a significant reduction in the porosity of the surface layer of the material and formation in the surface layer of a polycrystalline structure (grain size 15-60 μm) with a substructure in the form of crystallization cells (cell size 0.5-1.2 μm). Electron-beam processing of samples prepared by methods of conventional metallurgy for the indicated electron-beam parameters leads to the formation in the surface layer of a polycrystalline structure (grain size 50-800 μm) with a laminar intragrain substructure. Mechanical tests, performed by stretching flat samples, showed that the highest combination of mechanical strength and plasticity is possessed by samples obtained by layered selective electron-beam sintering with subsequent irradiation by an intense pulsed electron beam.

  19. Mask materials for powder blasting

    NARCIS (Netherlands)

    Wensink, H.; Jansen, Henricus V.; Berenschot, Johan W.; Elwenspoek, Michael Curt

    Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials such as glass, silicon and ceramics. The particle jet (which

  20. Advanced composites take a powder

    Energy Technology Data Exchange (ETDEWEB)

    Holty, D.W. (Custom Composite Materials, Inc., Atlanta, GA (United States))

    1993-06-01

    To a professional chemist with more than 25 years of industrial experience, the world of advanced composites is a fascinating new venue. Here resins and fibers come together in a completely synergistic partnership, achieving marvels of strength and light weight that make advanced composite materials virtually the only solution for challenging applications. In the late 1980s, Professor John Muzzy of the Georgia Institute of Technology, was intrigued by the physical properties of thermoplastics, and he developed a new way to bring the thermoplastic resins together with high-performance fibers. As part of the work Muzzy did with Lockheed and NASA he demonstrated that electrostatic powder coating was an attractive new method for combining thermoplastic resins with reinforcing fibers. Presentation of this work by Lockheed at a government-industry conference led to a new project for Muzzy, sponsored by NASA Langley. Powder prepregging proved to be the attractive alternative that NASA was looking for. While working on powder prepregging with LaRC-TPI, Muzzy and his colleagues developed methods for exposing all of the fibers to the powder to improve the distribution of the resin on the tow, a continuous bundle of filaments. Optimal resin distribution was achieved by spreading the moving tow. A very flexible towpreg was produced by maintaining the spread tow through the powder coating chamber and into the oven, where the resin particles were fused to the individual filaments. Muzzy's invention has enabled Custom Composite Materials, Inc. to offer resin/fiber combinations based on thermoplastic resins such as nylon and polypropylene. Beyond the expected advantages over epoxy thermoset systems, they are beginning to exploit a fundamental property of thermoplastic resins: viscoelasticity, which can be defined as the resistance to flow as a function of applied stress. Thermoplastics have a much higher viscoelasticity than thermosets.

  1. List of unclassified documents by the staff of Metallurgy Division, AERE Harwell from January 1972 to July 1977

    International Nuclear Information System (INIS)

    Wallis, V.

    1977-11-01

    This list constitutes unclassified material published or presented between January 1972 and July 1977 by the staff of Metallurgy Division. It covers reports, memoranda, bibliographies, articles in periodicals, conference papers, books, theses and patent specifications. It is planned to issue a list annually. The publications are listed under the following titles of the research teams concerned: fast reactor fuels, advanced reactor systems, fracture studies, structural materials, radiation effects, composite materials, high voltage microscope and metals fabrication, management and administration. (U.K.)

  2. [Factors of working environment and process on non-ferrous metallurgy enterprises in Bashkortostan Republic and workers' occupational health].

    Science.gov (United States)

    Bakirov, A B; Takaev, R M; Kondrova, N S; Shaĭkhlislamova, E R

    2011-01-01

    The authors studied factors of working environment and process on nonferrous metallurgy enterprises in Bashkortostan Republic and evaluated their influence on the workers' occupational health over 1997-2009, with consideration of occupation, sex, age, length of service, work conditions and characters. The article demonstrates that sanitary and hygienic characteristics of occupations connected with machinery operation are prone to increased integral evaluation of work conditions due to underestimation of actual hardiness and intensity of work.

  3. Near-Net Shape Fabrication Using Low-Cost Titanium Alloy Powders

    Energy Technology Data Exchange (ETDEWEB)

    Dr. David M. Bowden; Dr. William H. Peter

    2012-03-31

    feasibility studies were performed to identify the most viable approaches to NNS preform fabrication using basic powder metallurgy mill product forms as the building blocks and advanced joining techniques including fusion and solid state joining to assemble these building blocks into efficient machining performs.

  4. Development of structural diagram of automated dispatch control system for power consumption at non-ferrous metallurgy enterprises

    Science.gov (United States)

    Klyuev, R. V.; Bosikov, I. I.; Madaeva, M. Z.; A-V Turluev, R.

    2018-03-01

    The structural scheme of the automated control system of power consumption at the industrial enterprise is developed in the article. At the non-ferrous metallurgy enterprise, an energy inspection and a rank analysis of the electrical energy consumption of the main processing equipment were carried out. It is established that the enterprises of non-ferrous metallurgy are a complex process system consisting of a set of thousands of jointly functioning technological facilities. For the most effective estimation of power consumption of enterprises, it is reasonable to use the automated system of dispatching control of power consumption (ASDCPC). The paper presents the results of the development of the ASDCPC structural diagram that allows one to perform on-line control and management of the energy and process parameters of the main production units and the enterprise as a whole. As a result of the introduction of ASDCPC at the non-ferrous metallurgy enterprise, the consumed active power was reduced during the peak hours of the load by 20%, the specific electricity consumption - by 14%, the cost of the energy component in the cost of production of hard alloys - by 3%.

  5. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  6. Characteristics and Manufacture of Spherical Smokeless Powders

    OpenAIRE

    Botelho, Fernanda Diniz; Galante, Erick Braga Ferrão; Mendes, Álvaro José Boareto

    2015-01-01

    ABSTRACT: Smokeless propellants have been studied and manufactured for many decades. They can exist in various physical forms and also can have different properties according to the use of each propellant. One important form of smokeless powders is the ball powder, which has spherical grains. The manufacture process of the ball powder has many advantages over the usual way to manufacture a smokeless powder. For example, unstable and even deteriorated nitrocellulose, after being stabilized aga...

  7. Solidification and Microstructural Characterization on Atomized Powders

    Directory of Open Access Journals (Sweden)

    Şadi KARAGÖZ

    2009-03-01

    Full Text Available Powders produced by atomization techniques are commonly used in many industrial applications due to their many advantages such as homogeneous microstructure, low contamination and production of desired size range. In this study, the solidification of some ferrous and non-ferrous based alloy powders were considered and microstrucural characterization of all powder was carried out.

  8. 21 CFR 73.2645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.2645 Section 73.2645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and specifications to the requirements of...

  9. 21 CFR 73.1645 - Aluminum powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely divided particles of aluminum prepared from virgin aluminum. It...

  10. [Impact of directly compressed auxiliary materials on powder property of fermented cordyceps powder].

    Science.gov (United States)

    Chen, Li-Hua; Yue, Guo-Chao; Guan, Yong-Mei; Yang, Ming; Zhu, Wei-Feng

    2014-01-01

    To investigate such physical indexes as hygroscopicity, angle of repose, bulk density, fillibility of compression of mixed powder of directly compressed auxiliary materials and fermented cordyceps powder by using micromeritic study methods. The results showed that spray-dried lactose Flowlac100 and microcrystalline cellulose Avicel PH102 had better effect in liquidity and compressibility on fermented cordyceps powder than pregelatinized starch. The study on the impact of directly compressed auxiliary materials on the powder property of fermented cordyceps powder had guiding significant to the research of fermented cordyceps powder tablets, and could provide basis for the development of fermented cordyceps powder tablets.

  11. Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

    International Nuclear Information System (INIS)

    Wang, X.Y.; Zhang, Z.S.; Bai, T.

    2010-01-01

    The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

  12. Polycapillary optics for powder diffraction

    Science.gov (United States)

    Huang, Huapeng; MacDonald, Carolyn A.; Gibson, Walter M.; Chik, John; Parsegian, Adrian; Ponomarev, Igor Y.

    2001-12-01

    In this paper, we describe a low power system using Polycapillary collimating and focusing optics that were designed to collect Cu Ka radiation from an Oxford Ultra-Bright micro-focus source for X-ray powder diffraction measurements. The characterizations of the source and polycapillary optics are presented. A collimator with two apertures was used to block high energy X-rays. An optic alignment system was designed to optimize coupling between the optics and the source, taking into account the maximum radiation direction from the source. Several powder sample data sets were collected with this system and their qualities are compared with data sets from the same samples taken with an Enraf-Nonius FR590 sealed-tube source system. Discussion is also presented for further improving the performance of this low power system.

  13. Powder Diffraction in Zeolite Science

    Science.gov (United States)

    Burton, Allen W.

    This tutorial discusses the fundamental principles of X-ray diffraction and its applications in zeolite science. The early sections review the physics of diffraction, crystal symmetry, and reciprocal space. We discuss how the intensity of diffracted radiation is affected both by geometric effects involving detection (the Lorentz-polarization factor) and by the arrangement of atoms within the crystal (the structure factor). The differences between powder diffraction and single-crystal diffraction are then described, and differences between X-ray and neutron diffraction are also discussed. Later sections describe the effects of symmetry, lattice substitution, crystallite size, residual strain, preferred orientation, and X-ray absorption. Special emphasis is placed on the proper application of the Scherrer analysis in reporting crystalize size. The principles of structure solution from direct methods and Patterson methods are then introduced, and a description of Rietveld analysis is given. Finally the effects of stacking disorder on a powder diffraction pattern are presented.

  14. Cryogenic Milling of Titanium Powder

    Directory of Open Access Journals (Sweden)

    Jiří Kozlík

    2018-01-01

    Full Text Available Ti Grade 2 was prepared by cryogenic attritor milling in liquid nitrogen and liquid argon. Two types of milling balls were used—stainless steel balls and heavy tungsten carbide balls. The effect of processing parameters on particle size and morphology, contamination of powder and its microhardness was investigated. Milling in liquid nitrogen was not feasible due to excessive contamination by nitrogen. Minor reduction of particle size and significant alterations in particle morphology depended on type of milling balls and application of stearic acid as processing control agent. Heavily deformed ultra-fine grained (UFG internal microstructure of powder particles was observed by the method of “transmission Kikuchi diffraction”.

  15. Hot alpha-emitting particles in residue of mining and metallurgy

    International Nuclear Information System (INIS)

    Freyer, K.; Treutler, H.C.; Weiss, H.; Ghose, R.; Selchau-Hansen, K.; Enge, W.

    1998-01-01

    Industrial residues of ore processing and metallurgy partly contain significant amounts of natural radionuclides. Such fine-grained, contaminated materials e.g. are scrubber dust slurry in the Mansfeld region, known as Theisenschlamm, and tailings of the uranium ore processing. The environmental significance of these materials in particular is related to the high mobility of its fine grain fractions by air and on the water path. By autoradiography using solid state nuclear track detectors the homogeneity of the distribution of alpha-emitting radionuclides in the above mentioned materials has been investigated. It has been found that beside a homogeneous background distribution of the alpha activity single spots with significant higher activity concentration exist in form of hot particles. Its concentration in different contaminated materials has been determined. A surfactant treatment process has been applied to separate uranium tailings material in different grain size fractions. The fractions have been characterized chemically, radiometrically and with respect to the amount of alpha-active hot particles. (orig.) [de

  16. Possibilities for saving energy in ferrous metallurgy: Integration of technological processes

    Directory of Open Access Journals (Sweden)

    Mihailov Emil

    2016-01-01

    Full Text Available One of the main factors having a significant effect on fuel and energy saving in the production of rolled ferrous metals is matching the operation of the continuous casting machines (CCM with that of the reheating furnaces so called “continuous technologies” in the form of “direct rolling” or “hot charging”. In order to investigate the heat exchange processes, the opportunities for enhancing the energy efficiency and determining the optimal parameters of the flat product production process in ferrous metallurgy, some mathematical models of metal solidification and cooling in a continuous steel casting machine were determined as well as a mathematical model of metal heating in the reheating furnaces. For efficient implementation of such technologies one common algorithm was built on the basis of the individual mathematical models, representing the continuous casting - rolling mill complex control technology, dynamically matching the operation of the individual units to the actual production conditions in on-line mode. The developed algorithm can be used as part of a system for analyzing the thermal condition of the blocks at any single moment for the purpose of optimization of the units’ operation within the whole technological process. As a conclusion, considering the original developed algorithm, a 21-51% energy saving was noticed.

  17. Air Emissions of Selected Substances from Particular Sectors Including Metallurgy in Poland

    Directory of Open Access Journals (Sweden)

    Kargulewicz I.

    2017-03-01

    Full Text Available This article presents data on the anthropogenic air emissions of selected substances (CO2, SO2, total suspended particles (TSP, dioxins and furans (PCDD/F, Pb and Cd subject to reporting under the Climate Convention (UNFCCC or the Convention on Long-range Transboundary Air Pollution (UNECE CLRTAP. It also presents the national emissions of these substances in 2014 by the major source categories and defines the share of metal production in these emissions. Analysis is based on national emission inventory reports. Most important source of air emission in case of CO2 and SO2 is 1.A.1 Energy industries category. TSP and PCDD/F are emitted mainly from fuel combustion in small sources (i.a. households. Emission of heavy metals (Pb and Cd is connected mostly with 1.A.2. Manufacturing industries and construction category. Metallurgy is significant source of emission only for lead and cadmium from among all considered substances. The shares of particular sectors in the national emissions of given pollutants are important, in view of the possible reduction measures and the determination in which industries they could bring about tangible results.

  18. Physical Protection Study of the Radio metallurgy Installation Using SAVIComputer Program

    International Nuclear Information System (INIS)

    Pinitoyo, Andreas

    2000-01-01

    Based on IAEA Recommendation on INFCIR/225/Rev.3 (The Physical Protectionof Nuclear Material), a nuclear installation shall have physical protectionsystem for protection or being secure on sabotage activities in theinstallation and thieve of nuclear materials. The recommendation states therequirements for physical protection of nuclear materials usage, transit andstorage. Radio metallurgy Installation of the Fuel Element and ReprocessingDevelopment Center (BATAN) at Serpong is a nuclear installation for researchon post irradiation of high radioactive spent fuel element, its processingand storage. The installation has risk on threat of a sabotage, which isdominant than thieve. The RMI building was designed and constructed ofphysical protection components and have been integrated with the BATAN Safetyand Security System and the Security Guards functions to be PhysicalProtection System for the RMI. By using the SAVI Computer Program with inputdata from the existing standards, assumptions for detection possibility,delay and response, that will result the probability of interruptions of theworst adversary paths PI = 0.1. These mean that the physical protectionsystems of the RMI shall be upgraded and improved in order to be reliable orbetter if the most of paths to the target PI = 1.0. (author)

  19. Bridging the gap between metallurgy and fatigue reliability of hydraulic turbine runners

    International Nuclear Information System (INIS)

    Thibault, D; Gagnon, M; Godin, S

    2014-01-01

    The failure of hydraulic turbine runners is a very rare event. Hence, in order to assess the reliability of these components, one cannot rely on statistical models based on the number of failures in a given population. However, as there is a limited number of degradation mechanisms involved, it is possible to use physically-based reliability models. Such models are more complicated but have the advantage of being able to account for physical parameters in the prediction of the evolution of runner degradation. They can therefore propose solutions to help improve reliability. With the use of such models, the effect of materials properties on runner reliability can easily be illustrated. This paper will present a brief review of the Kitagawa-Takahashi diagram that links the damage tolerance approach, based on fracture mechanics, to the stress or strain-life approaches. This diagram is at the centre of the reliability model used in this study. Using simplified response spectra obtained from on-site runner stress measurements, the paper will show how fatigue reliability is impacted by materials fatigue properties, namely fatigue crack propagation behaviour and fatigue limit obtained on S-N curves. It will also present a review of the most important microstructural features of 13%Cr- 4%Ni stainless steels used for runner manufacturing and will review how they influence fatigue properties in an effort to bridge the gap between metallurgy and turbine runners reliability

  20. Reuse of beneficiency residue from mining and metallurgy as source of zeolites

    International Nuclear Information System (INIS)

    Souza, J.A.S.; Rodrigues, E.C.; Souza, J.A.S.; Neves, R.F.; Macedo, E.N.; Moraes, C.G.

    2011-01-01

    The mining industry and metallurgy, located in Para State, brought the concern about the huge generation of solid waste (eg The Red Mud (LV) industry Alumina; waste alumina sand-kaolin industry, waste of cuba electrolytic aluminum industry and other metal) and with the gas emissions from the burning of fossil fuels these industries. In the case of solid waste, most of which require special care such as check dams and even storage areas protected. Since the waste gases are not always properly treated and are one of the most discussed environmental problem today, according to the emission of compounds such as SOx, NOx, Cox's treatment of these effluents should be given, necessarily involves techniques of adsorption followed by reaction neutralization. These techniques can be used in two ways: by wet and dry. In the specific case of gas emissions from fossil fuels is used to wash using aqueous suspensions of calcium oxide. In this context, studies conducted in the Laboratory of Ceramic Materials, UFPA [1, 2], showed that the Bayer process residue (red mud) has characteristics that indicate the possibility of its use in place of calcium oxide in the treatment of waste gases. Moreover, waste from kaolin industry can be used as adsorbents since they go through a process of synthesis, producing different types of synthetic zeolites can be extremely useful in the treatment of waste and various activities related to environmental issues. (author)

  1. Emissions from Pre-Hispanic Metallurgy in the South American Atmosphere

    Science.gov (United States)

    De Vleeschouwer, François; Vanneste, Heleen; Mauquoy, Dmitri; Piotrowska, Natalia; Torrejón, Fernando; Roland, Thomas; Stein, Ariel; Le Roux, Gaël

    2014-01-01

    Metallurgical activities have been undertaken in northern South America (NSA) for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA) over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA. PMID:25353346

  2. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Directory of Open Access Journals (Sweden)

    François De Vleeschouwer

    Full Text Available Metallurgical activities have been undertaken in northern South America (NSA for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  3. Emissions from pre-Hispanic metallurgy in the South American atmosphere.

    Science.gov (United States)

    De Vleeschouwer, François; Vanneste, Heleen; Mauquoy, Dmitri; Piotrowska, Natalia; Torrejón, Fernando; Roland, Thomas; Stein, Ariel; Le Roux, Gaël

    2014-01-01

    Metallurgical activities have been undertaken in northern South America (NSA) for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA) over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

  4. State-of-the-art of recycling e-wastes by vacuum metallurgy separation.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2014-12-16

    In recent era, more and more electric and electronic equipment wastes (e-wastes) are generated that contain both toxic and valuable materials in them. Most studies focus on the extraction of valuable metals like Au, Ag from e-wastes. However, the recycling of metals such as Pb, Cd, Zn, and organics has not attracted enough attentions. Vacuum metallurgy separation (VMS) processes can reduce pollution significantly using vacuum technique. It can effectively recycle heavy metals and organics from e-wastes in an environmentally friendly way, which is beneficial for both preventing the heavy metal contaminations and the sustainable development of resources. VMS can be classified into several methods, such as vacuum evaporation, vacuum carbon reduction and vacuum pyrolysis. This paper respectively reviews the state-of-art of these methods applied to recycling heavy metals and organics from several kinds of e-wastes. The method principle, equipment used, separating process, optimized operating parameters and recycling mechanism of each case are illustrated in details. The perspectives on the further development of e-wastes recycling by VMS are also presented.

  5. Manufacture of uranium dioxide powder

    International Nuclear Information System (INIS)

    Becker, M.

    1976-01-01

    Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen carbonate or an NH 4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol

  6. Terahertz dielectric measurements of household powders

    Science.gov (United States)

    Khan, Usman A.; Afsar, Mohammed N.

    2007-09-01

    The dielectric properties of common household powders from 0.6 to 1.2 THz are presented in this paper. Terahertz Dispersive Fourier Transform Spectroscopy was used to yield the dielectric properties of powders as a continuous function of frequency. Tests were conducted using a polarized interferometer and two cryogenically-cooled high frequency detectors. Dielectric spectroscopy was utilized to provide high-resolution and precise information on the dielectric spectra of powders including the powder's unique resonance signature. This signature can be employed to detect the presence of a hoax or harmful powder within a baggage or mail package.

  7. [Advances in studies on bear bile powder].

    Science.gov (United States)

    Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

    2015-04-01

    In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

  8. Dynamic compaction of ceramic powders

    Energy Technology Data Exchange (ETDEWEB)

    Cline, C.F.

    1982-06-10

    Dynamic consolidation is a technique for densifying powder ensembles to near theoretical with or without external application of heat. The technique itself is simple: the confined powder, initially at a green density of approx. 50% encounters a high pressure shock wave which exceeds the yield strength and densifies as the wave proceeds through the compact. The time scales and pressure range from 1-10's of microseconds and 10-100's of kilobars (10 Kb = 1 GPa). The short time scale of the pressure pulse during the compaction stage inhibits kinetic processes which have longer time constants. The pressure pulse can be delivered to the green compact by a number of techniques, i.e. high explosive, projectile. The methods differ in the degree that one can control the amplitude, duration, and nature of the pressure pulse. The lecture compares powders compacted by explosive and light gas guns and when possible characterize their resulting structures and properties, using AlN as example. 14 figures.

  9. Effects of Initial Powder Size on the Mechanical Properties and Microstructure of As-Extruded GRCop-84

    Science.gov (United States)

    Okoro, Chika L.

    2004-01-01

    GRCop-84 was developed to meet the mechanical and thermal property requirements for advanced regeneratively cooled rocket engine main combustion chamber liners. It is a ternary Cu- Cr-Nb alloy having approximately 8 at% Cr and 4 at% Nb. The chromium and niobium constituents combine to form 14 vol% Cr2Nb, the strengthening phase. The alloy is made by producing GRCop-84 powder through gas atomization and consolidating the powder using extrusion, hot isostatic pressing (HIP) or vacuum plasma spraying (VPS). GRCop-84 has been selected by Rocketdyne, Ratt & Wlutney and Aerojet for use in their next generation of rocket engines. GRCop-84 demonstrates favorable mechanical and thermal properties at elevated temperatures. Compared to NARloy-Z, the currently used inaterial in the Space Shuttle, GRCop-84 has approximately twice the yield strength, 10-1000 times the creep life, and 1.5-2.5 times the low cycle fatigue life. The thermal expansion of GRCop-84 is 7515% less than NARloy-Z which minimizes thermally induced stresses. The thermal conductivity of the two alloys is comparable at low temperature but NARloy-Z has a 20-50 W/mK thermal conductivity advantage at typical rocket engine hot wall temperatures. GRCop-84 is also much more microstructurally stable than NARloy-Z which translates into better long term stability of mechanical properties. Previous research into metal alloys fabricated by means of powder metallurgy (PM), has demonstrated that initial powder size can affect the microstructural development and mechanical properties of such materials. Grain size, strength, ductility, size of second phases, etc., have all been shown to vary with starting powder size in PM-alloys. This work focuses on characterizing the effect of varying starting powder size on the microstructural evolution and mechanical properties of as- extruded GRCop-84. Tensile tests and constant load creep tests were performed on extrusions of four powder meshes: +140 mesh (great3er than l05 micron

  10. Effect of milling duration on the evolution of shape memory properties in a powder processed Cu-Al-Ni-Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mohit; Gupta, Gaurav K.; Shafeeq, Muhamed M.; Modi, Om P.; Prasad, Braj K. [CSIR - Advanced Materials and Processes Research Institute, Bhopal (India)

    2013-09-15

    The present work describes the effect of milling duration on the properties of a powder metallurgy processed Cu-Al-Ni-Ti shape memory alloy employing mechanical alloying. Powder mixtures milled for different durations were sintered in order to investigate the formation of solid solution and evolution of martensitic structure. The idea was to optimize the duration of milling (mechanical alloying) to obtain chemical homogeneity as well as shape memory properties in the processed material without undergoing extensive post homogenization treatment. The martensitic structure was noted to evolve in the powder mix milled for at least 16 hrs, whereas complete transformation to martensite occurred after milling for 40 hrs. Interestingly, the dissolution of alloying elements (to form the {beta} phase prior to the formation of martensite) was noted to complete partially only during mechanical alloying for 40 hrs and remaining during subsequent sintering for 1 hr. The hot pressed compacts of the powders milled for 40 hrs were chemically homogeneous and consisted of fully martensite phase, which is essential for the realization of shape memory properties. They also revealed almost 100% shape recovery at the applied pre-strain levels of 1 and 2%. (orig.)

  11. The utilization of mechanochemistry in the extractive metallurgy and at the nanocrystalline materials preparation

    Directory of Open Access Journals (Sweden)

    Boldižárová Eva

    2002-03-01

    Full Text Available The possibility of the application of mechanochemistry in the extractive metallurgy and the nanocrystalline materials preparation is studied. The aim of the experiments is the chloride leaching of a complex sulphidic CuPbZn concentrate (Hodruša-Hámre, the modification of properties of CaCO3 (Yauli, Peru for zinc sorption from model solutions and the mechanochemical reduction of copper sulphide by elemental iron.The chloride leaching of mechanically activated complex sulphidic CuPbZn concentrate is a selective process. While the recoveries of copper, lead and zinc are 65-85 %, the recoveries of silver and gold are less than 7 % and 2 %, respectively.The positive influence of CaCO3 mechanical activation for zinc sorption from ZnSO4 solution was observed. While only 58 % of zinc sorption was determined after 30 minutes for a non-activated sample, 98 % of zinc sorption was determined after 3 minutes sorption for the sample mechanically activated for 15 minutes.By the mechanochemical reduction of copper sulphide with iron, nanocrystalline copper and iron sulphide are formed. This reaction is an example of the new “solid state technology“, where chemical processes in the gaseous and liquid states are excluded.The results can serve as a contribution to the optimization of copper, lead and zinc extraction from complex sulphidic concentrates, the increase of non-ferrous metals sorption efficiency on mineral sorbents as well as to the nanocrystalline copper preparation.The application of mechanical activation has grown in the laboratory research. The Institute of Geotechnics of SAS has also achieved significant theoretical results in study of mechanical activation of sulphides and their reactivity in the different solid-phase reactions with the effect on industrial applications. The Institute has developed the technology of mechanochemical leaching (process MELT which was successfully tested in a pilot plant unit.

  12. The metallurgy, mechanics, modelling and assessment of dissimilar material brazed joints

    International Nuclear Information System (INIS)

    Hamilton, Niall Robert; Wood, James; Galloway, Alexander; Olsson Robbie, Mikael Brian; Zhang Yuxuan

    2013-01-01

    At the heart of any procedure for modelling and assessing the design or failure of dissimilar material brazed joints there must be a basic understanding of the metallurgy and mechanics of the joint. This paper is about developing this understanding and addressing the issues faced with modelling and predicting failure in real dissimilar material brazed joints and the challenges still to be overcome in many cases. An understanding of the key metallurgical features of such joints in relation to finite element modelling is presented in addition to a study of the mechanics and stress state at an abrupt interface between two materials. A discussion is also presented on why elastic singularities do not exist based on a consideration of the assumption of an abrupt change in material properties and plasticity in the vicinity of the joint. In terms of modelling real dissimilar material brazed joints; there are several barriers to accurately capturing the stress state in the region of the joint and across the brazed layer and these are discussed in relation to a metallurgical study of a real dissimilar material brazed joint. However, this does not preclude using a simplified modelling approach with a representative braze layer in design and failure assessment away from the interface. In addition modelling strategies and techniques for assessing the various failure mechanisms of dissimilar material brazed joints are discussed. The findings from this paper are applicable to dissimilar material brazed joints found in a range of applications; however the references listed are primarily focussed on work in fusion research and development.

  13. PIXE analysis of powdered milk

    International Nuclear Information System (INIS)

    Hallak, A.B.

    1983-01-01

    An accelerator-based study, using proton-induced x-ray emission (PIXE) was performed on four full-cream and four half-cream brands of powdered milk commonly consumed in Jordan. The elements detected in the samples are S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. The significance of some of these elements is discussed from the viewpoint of nutrition and also their effect on milk processing and dairy technology. The standard reference milk sample, A-11, which is distributed by IAEA was also examined, and the results for trace elements detected are compared with the values certified by IAEA. (author)

  14. GRANULATION TRIALS OF WASTE THE DUST SILICON CARBIDE FOR UTILIZATION IN METALLURGY

    Directory of Open Access Journals (Sweden)

    Gabriel Borowski

    2016-09-01

    Full Text Available The article presents the results of laboratory granulation tests of dust silicon carbide and the results of research on the selection of the binder and the properties of the granules obtained. The research material was a waste of the silicon carbide powder with a high fragmentation, mixed with a cement or an organic modified starch specimen. Six tests were performed in a disc granulator with 100 cm in diameter. In each series of trial specified: the type and share of the binder, the diameter of the granules, tenderness, type of structure and mechanical properties. Good granules of silicon carbide obtained with the addition of cement binder with 4% of the mass fraction and at least 24 hours of seasoning. The binder should be added twice by powdering, first in a stirred granulator, and again after manufacture. It was found that the resulting granules may be used as a replacement of ferrosilicon in the process of steelmaking.

  15. Estimation of snow pollution in the region of non-ferrous metallurgy enterprises by the neutron activation method

    International Nuclear Information System (INIS)

    Khatamov, Sh.; Khamidova, R.; Kist, A.A.

    1980-01-01

    Possibility of determination of more than 25 chemical elements in snow water selected in the region of non-ferrous metallurgy enterprises has been shown using the methods of neutron activation and γ-spectrometry of high resolution. Elements were determined from one sample by three-fold irradiation in the nuclear reactor depending on the half-life period and other nuclear activation parameters of the formed radioisotopes. The analysis of snow cover has revealed the character of pollution of surrounding medium and air basin by toxical elements

  16. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Martínez Cortizas, Antonio, E-mail: antonio.martinez.cortizas@usc.es [Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur s/n, Santiago de Compostela (Spain); López-Merino, Lourdes, E-mail: lourdes.lopez-merino@brunel.ac.uk [Institute of Environment, Health and Societies, Brunel University London, UB8 3PH Uxbridge (United Kingdom); Bindler, Richard, E-mail: richard.bindler@umu.se [Department of Ecology and Environmental Science, Umeå University, Umeå (Sweden); Mighall, Tim, E-mail: t.mighall@abdn.ac.uk [Department of Geography & Environment, School of Geosciences, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Kylander, Malin E., E-mail: malin.kylander@geo.su.se [Department of Geological Sciences and the Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm (Sweden)

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~ 3500–3200 cal. yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (> 2100 cal. yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35–100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~ 8000 to ~ 4980 cal. yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g{sup −1}; {sup 206}Pb/{sup 207}Pb 1.204 ± 0.002). A sustained period of low {sup 206}Pb/{sup 207}Pb ratios occurred from ~ 4980 to ~ 2470 cal. yr. BP, which can be divided into four phases: Chalcolithic (~ 4980–3700 cal. yr. BP), {sup 206}Pb/{sup 207}Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~ 3700–3500 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~ 3500–2800 cal. yr. BP), {sup 206}Pb/{sup 207}Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~ 2800–2470 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, {sup 206}Pb/{sup 207}Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the

  17. Study of Proper Time Range for Current Flow to Resistance Spot Welding Inspected by Mechanical Property and Metallurgy Testing

    International Nuclear Information System (INIS)

    Pearsura, Prachya

    2007-08-01

    Full text: This research used the mechanical property and metallurgy testing to identify the proper time range for current flow. The specimen tested was 1 mm thick mild steel. The welded specimens were tested by Tensile Shear testing following JIS Z 3136: 1999 and Macro Structure testing follow by JIS Z 3139: 1978. Subsequently, the results from analyzing were compared with standard JIS Z 3140. The results show that the suitable current flow is 8 to 10 cycles. This technique can be applied to monitor the process and the quality of resistance spot welding

  18. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe.

    Science.gov (United States)

    Martínez Cortizas, Antonio; López-Merino, Lourdes; Bindler, Richard; Mighall, Tim; Kylander, Malin E

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal.yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~8000 to ~4980 cal.yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g(-1); (206)Pb/(207)Pb 1.204 ± 0.002). A sustained period of low (206)Pb/(207)Pb ratios occurred from ~4980 to ~2470 cal.yr. BP, which can be divided into four phases: Chalcolithic (~4980-3700 cal.yr. BP), (206)Pb/(207)Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~3700-3500 cal.yr. BP), (206)Pb/(207)Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~3500-2800 cal.yr. BP), (206)Pb/(207)Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~2800-2470 cal.yr. BP), (206)Pb/(207)Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, (206)Pb/(207)Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and

  19. Annual Report on Scientific Activities in 1997 of Department of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Cracow

    International Nuclear Information System (INIS)

    Wolny, J.; Olszynska, E.

    1998-01-01

    The Annual Report 1997 is the review of scientific activities of the Department of Nuclear Physics and Techniques (DNPT) of the Academy of Mining and Metallurgy, Cracow. The studies connected with: radiometric analysis, nuclear electronics, solid state physics, elementary particle and detectors, medical physics, physics of environment, theoretical physics, nuclear geophysics, energetic problems, industrial radiometry and tracer techniques have been broadly presented. The fill list of works being published and presented at scientific conferences in 1997 by the staff of DNPT are also included

  20. Isostatic pressing of metal powders

    International Nuclear Information System (INIS)

    Cytermann, R.; Auguin, B.; Defresne, A.; Gilles, P.

    1975-01-01

    The process of powders compaction is of great technical importance for the attainment of sintered bodies of high density and strength, or of bodies with controlled porosity. For this purpose, different carbonyl nickel and carbonyl iron powders were isostatically compacted at pressures from 50 to 1300 MN/m 2 (0.5-13kbars). The density of compacts was determined by stereology (quantitative microscopic analysis) and weighing. The two methods were found to be in very good agreement and permit to correlate the density of the compact with the applied pressure, while differentiating the stages of compaction (particle rearrangement, local and homogeneous plastic flow) and showing off the influence of material properties (particle size distribution, particle sphape, ability of the particles to deform, yield stress required for deformation, etc...) The way from one stage to the other was corroborated by scanning electron microscope observation and X-rays diffraction. Electrical resistance and tensile strength measurements were also carried out and permitted to correlate these parameters and the applied pressure [fr

  1. Smart particle production, characterization and powder forensics

    OpenAIRE

    Fang, Yuan

    2017-01-01

    Powdered food ingredients are common yet important in our daily life. The most well-known method to produce these powdered products is via spray drying. Nowadays, it is possible to customize the spray dried products with desired nutrition/physiochemical properties according to the requirements and demands of the consumer market. Powders resulting from different processes (or different process conditions) vary significantly in composition and the functional behaviours. This renders traditional...

  2. In-house characterization of protein powder

    DEFF Research Database (Denmark)

    Hartmann, Christian Grundahl; Nielsen, Ole Faurskov; Ståhl, Kenny

    2010-01-01

    X-ray powder diffraction patterns of lysozyme and insulin were recorded on a standard in-house powder diffractometer. The experimental powder diffraction patterns were compared with patterns calculated from Protein Data Bank coordinate data. Good agreement was obtained by including straightforward...... to include calculated H-atom positions did not improve the overall fit and was abandoned. The method devised was shown to be a quick and convenient tool for distinguishing precipitates and polymorphs of proteins....

  3. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  4. Preparation techniques for ceramic waste form powder

    International Nuclear Information System (INIS)

    Hash, M.C.; Pereira, C.; Lewis, M.A.

    1997-01-01

    The electrometallurgical treatment of spent nuclear fuels result in a chloride waste salt requiring geologic disposal. Argonne National Laboratory (ANL) is developing ceramic waste forms which can incorporate this waste. Currently, zeolite- or sodalite-glass composites are produced by hot isostatic pressing (HIP) techniques. Powder preparations include dehydration of the raw zeolite powders, hot blending of these zeolite powders and secondary additives. Various approaches are being pursued to achieve adequate mixing, and the resulting powders have been HIPed and characterized for leach resistance, phase equilibria, and physical integrity

  5. Atom probe tomography analysis of WC powder

    Energy Technology Data Exchange (ETDEWEB)

    Weidow, Jonathan, E-mail: jonathan.weidow@chalmers.se [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, A-1060 Wien (Austria)

    2013-09-15

    A tantalum doped tungsten carbide powder, (W,Ta)C, was prepared with the purpose to maximise the amount of Ta in the hexagonal mixed crystal carbide. Atom probe tomography (APT) was considered to be the best technique to quantitatively measure the amount of Ta within this carbide. As the carbide powder consisted in the form of very small particles (<1 μm), a method to produce APT specimens of such a powder was developed. The powder was at first embedded in copper and a FIB-SEM workstation was used to make an in-situ lift-out from a selected powder particle. The powder particle was then deposited on a post made from a WC-Co based cemented carbide specimen. With the use of a laser assisted atom probe, it was shown that the method is working and the Ta content of the (W,Ta)C could be measured quantitatively. - Highlights: ► Method for producing atom probe tomography specimens of powders was developed. ► Method was successfully implemented on (W,Ta)C powder. ► Method can possibly be implemented on completely other powders.

  6. Sintering, microstructure and properties of WC-AISI304 powder composites

    Energy Technology Data Exchange (ETDEWEB)

    Marques, B.J. [Department of Materials and Ceramic Engineering, CICECO University of Aveiro, 3810-193 Aveiro (Portugal); Fernandes, C.M., E-mail: cmfernandes@ua.pt [Department of Materials and Ceramic Engineering, CICECO University of Aveiro, 3810-193 Aveiro (Portugal); ISEC, Mechanical Department, Engineering Institute of Coimbra, Rua Pedro Nunes, 3030-199 Coimbra (Portugal); Senos, A.M.R. [Department of Materials and Ceramic Engineering, CICECO University of Aveiro, 3810-193 Aveiro (Portugal)

    2013-06-15

    Highlights: ► Total replacement of Co binder by stainless steel AISI 304 in WC based composites. ► Processing conditions for WC–stainless steel composites. ► Mechanical behavior and oxidation resistance of WC–stainless steel composites. -- Abstract: Tungsten carbide–stainless steel (AISI 304) based composites were successfully prepared by powder metallurgy routes using vacuum sintering at a maximum temperature of 1500 °C. The effects of the binder amount (between 6 and 15 wt.%) on the phase composition, microstructure and mechanical properties, namely hardness and fracture toughness, were investigated. Appreciable amount of (M,W){sub 6}C up to 12 wt.% was detected, especially for the higher SS contents. However, a good compromise between toughness and hardness was observed. Besides that, improved oxidation resistance was noticed in WC–SS based composites compared with WC–Co composites. The results are discussed having in mind the correlation between chemical composition, phase composition, microstructure and mechanical behavior.

  7. 77 FR 28252 - Oral Dosage Form New Animal Drugs; Change of Sponsor; Griseofulvin Powder; Levamisole...

    Science.gov (United States)

    2012-05-14

    ... Sponsor; Griseofulvin Powder; Levamisole Hydrochloride Powder; Oxytetracycline Powder AGENCY: Food and... applications (ANADAs) for griseofulvin powder, levamisole hydrochloride soluble powder, and oxytetracycline..., ANADA 200-391 for Griseofulvin Powder, ANADAs 200-146 and 200-247 for Oxytetracycline Hydrochloride...

  8. Advances in powder diffraction crystallography

    International Nuclear Information System (INIS)

    Magneli, A.

    1986-01-01

    This is the first conference to be arranged within the framework of an agreement on scientific exchange and co-operation between l Academie des Sciences de l Institut de France and the Royal Swedish Academy of Sciences. The responsibility for the scientific program of the conference has been shared between members of the two Academies. The contributions include glimpses of the historical background and broad reviews of the present status of development and of recent work in powder crystallography. Reports are given on a number of studies, basic as well as applied in character, currently conducted in the two countries in a large variety of fields. Prospects of further developments in the area are also presented

  9. Reflection measurements for luminescent powders

    Science.gov (United States)

    Kroon, R. E.

    2018-04-01

    Luminescent materials are useful in applications varying from lighting and display technologies to document security features and medical research, amongst many others. Measurement of the excitation range is an important consideration, and absorption bands are often determined from a decrease in the measured diffuse reflectance of the material using a ultraviolet-visible (UV-vis) spectrophotometer with an integrating sphere. Such a system may provide questionable results when used to measure the reflectance of a luminescence material, which is demonstrated for a Tb doped silica phosphor, because the system cannot differentiate between the reflected light and luminescence. It is shown that more reliable results are achieved for this phosphor by measuring the reflectance using a synchronous zero-offset scan in a fluorescence spectrometer equipped with an integrating sphere. This method is therefore recommended instead of traditional reflectance measurements using a UV-vis spectrophotometer for luminescent powders.

  10. New detectors for powders diagrams

    International Nuclear Information System (INIS)

    Convert, P.

    1975-01-01

    During the last few years, all the classical neutron diffractometers for powders have used one or maybe a few counters. So, it takes a long time to obtain a diagram which causes many disadvantages: 1) very long experiments: one or two days (or flux on the sample about 10 6 n/cm 2 /a); 2) necessity of big samples: many cm 3 ; 3) necessity of having the whole diagram before changing anything in the experiment: magnetic field, temperature, quality of the sample; 4) necessity of having collimators of a few times ten minutes to obtain correct statistics in the diagram. Because of these disadvantages, several attempts have been made to speed up the experimental procedure such as using more counters, the detection of neutrons on a resistive wire, etc. In Grenoble, new position-sensitive detectors have been constructed using a digital technique

  11. Contribution to the study of copper and copper-arsenic archaeo-metallurgy using light element analysis and experimental fusion

    International Nuclear Information System (INIS)

    Papillon, F.

    1997-01-01

    The objective of this study is to try a direct reconstruction from ancient artefacts of the elaboration technology used in the dawning copper metallurgy. This word is based on both the light elements analysis and the carry out of the principles of physical metallurgy. However the study of an archaeological artefact necessitates the use of non destructive methods. A main aspect of this work consists in developing the most adequate metallographic technique and the methods for the determination of oxygen and carbon by ion beam analysis. Additionally experimental melting of copper and copper arsenic alloys were carried out in laboratory, under various temperature and atmosphere conditions, and 'on the field' in Archeodrome de Beaune, in order to reconstruct part of the prehistorical craftsmanship. The results of measurement are consistent with our general knowledge of oxido-reduction phenomena and the behaviour of copper and copper arsenic alloys s in agreement with the prediction of thermodynamics. The nuclear analysis of three ancient artefacts showed that the oxygen and carbon contents were closer to those of the Archeodrome than those of the laboratory. Further studies of the field should consider all parameters controlling the physical-chemistry of charcoal fire. (author)

  12. Comprehensive waste characterization and organic pollution co-occurrence in a Hg and As mining and metallurgy brownfield.

    Science.gov (United States)

    Gallego, J R; Esquinas, N; Rodríguez-Valdés, E; Menéndez-Aguado, J M; Sierra, C

    2015-12-30

    The abandonment of Hg-As mining and metallurgy sites, together with long-term weathering, can dramatically degrade the environment. In this work it is exemplified the complex legacy of contamination that afflicts Hg-As brownfields through the detailed study of a paradigmatic site. Firstly, an in-depth study of the former industrial process was performed to identify sources of different types of waste. Subsequently, the composition and reactivity of As- and Hg-rich wastes (calcines, As-rich soot, stupp, and flue dust) was analyzed by means of multielemental analysis, mineralogical characterization (X-ray diffraction, electronic, and optical microscopy, microbrobe), chemical speciation, and sequential extractions. As-rich soot in the form of arsenolite, a relatively mobile by-product of the pyrometallurgical process, and stupp, a residue originated in the former condensing system, were determined to be the main risk at the site. In addition, the screening of organic pollution was also aimed, as shown by the outcome of benzo(a) pyrene and other PAHs, and by the identification of unexpected Hg organo-compounds (phenylmercury propionate). The approach followed unravels evidence from waste from the mining and metallurgy industry that may be present in other similar sites, and identifies unexpected contaminants overlooked by conventional analyses. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Protons in hydrated protein powders

    International Nuclear Information System (INIS)

    Careri, G.; Bruni, F.; Consolini, G.

    1995-01-01

    Previous work from this laboratory has shown that hydrated lysozyme powders exhibit a dielectric behaviour, due to proton conductivity, explainable within the frame of percolation theory. Long range proton displacement appears only above the critical hydration for percolation, when the 2-dimensional motion takes place on fluctuating clusters of hydrogen-bonded water molecules adsorbed on the protein surface. The emergence of biological function, enzyme catalysis, was found to coincide with the critical hydration for percolation. More recently, we have evaluated the protonic conductivity of hydrated lysozyme powders, from room down to liquid N 2 temperature. In the high temperature limit a classical isotopic effect can be detected, and the conductivity follows the familiar Arrhenius law for thermally activated hopping. In the low temperature region the conductivity shows a temperature dependence in agreement with prediction by the theory of dissipative quantum tunneling. Below room temperature the static dielectric constant, and the dielectric relaxation time for charge transport showed an increase likely to be identified with the formation of a polaronic-solitonic species as predicted by the theory of proton transport in water chains, a species which displays a larger effective mass and a larger dipole moment that the usual hydrated protonic defects. The purpose of this paper is twofold. In the first section we present a tutorial report of some previous experimental results on proton displacement in slightly hydrated biological systems at room temperature, to show that in these systems the emergence of biological systems at room temperature, to show that in these systems the emergence of biological function coincides with the onset of percolative pathways in the water molecules network adsorbed on the surface of biomolecules. In the second section, we report on preliminary data on the dielectric relaxation of hydrated lysozyme below room temperature, to suggest

  14. Obtaining zircaloy powder through hydriding

    International Nuclear Information System (INIS)

    Dupim, Ivaldete da Silva; Moreira, Joao M.L.

    2009-01-01

    Zirconium alloys are good options for the metal matrix in dispersion fuels for power reactors due to their low thermal neutron absorption cross-section, good corrosion resistance, good mechanical strength and high thermal conductivity. A necessary step for obtaining such fuels is producing Zr alloy powder for the metal matrix composite material. This article presents results from the Zircaloy-4 hydrogenation tests with the purpose to embrittle the alloy as a first step for comminuting. Several hydrogenation tests were performed and studied through thermogravimetric analysis. They included H 2 pressures of 25 and 50 kPa and temperatures ranging between from 20 to 670 deg C. X-ray diffraction analysis showed in the hydrogenated samples the predominant presence of ZrH 2 and some ZrO 2 . Some kinetics parameters for the Zircaloy-4 hydrogenation reaction were obtained: the time required to reach the equilibrium state at the dwell temperature was about 100 minutes; the hydrogenation rate during the heating process from 20 to 670 deg C was about 21 mg/h, and at constant temperature of 670 deg C, the hydride rate was about 1.15 mg/h. The hydrogenation rate is largest during the heating process and most of it occurs during this period. After hydrogenated, the samples could easily be comminuted indicating that this is a possible technology to obtain Zircaloy powder. The results show that only few minutes of hydrogenation are necessary to reach the hydride levels required for comminuting the Zircaloy. The final hydride stoichiometry was between 2.7 and 2.8 H for each Zr atom in the sample (author)

  15. Whey powder sterilization by ionizing irradiation

    International Nuclear Information System (INIS)

    Todorovic, M.; Salatic, Z.; Markov, S.

    1988-01-01

    Whey powder was sterilized by gamma waves application. As a source of irridiation isotope 60Co was used in Institute of Nuclear sciences B oris Kidrich , Vincha-Belgrade (Yugoslavia). The applied doses were: a, b, c, d, and e Kgy. The dose d was radappertization. After whey powder irradiation no adverse changes of organoleptic properties were noticed

  16. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a temperature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders prepared ...

  17. 21 CFR 73.1646 - Bronze powder.

    Science.gov (United States)

    2010-04-01

    ... percent. Maximum particle size 45µ (95 percent minimum). Aluminum, zinc, tin, and copper content shall be based on the weight of the dried powder after being thoroughly washed with ether. (c) Uses and restrictions. Bronze powder may be safely used in color externally applied drugs, including those intended for...

  18. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    Unknown

    Abstract. High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a tem- perature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders.

  19. Solving Crystal Structures from Powder Diffraction Data

    DEFF Research Database (Denmark)

    Christensen, A. Nørlund; Lehmann, M. S.; Nielsen, Mogens

    1985-01-01

    High resolution powder data from both neutron and X-ray (synchrotron) sources have been used to estimate the possibility of direct structure determination from powder data. Two known structures were resolved by direct methods with neutron and X-ray data. With synchrotron X-ray data, the measured ...

  20. Antibacterial activity of some powdered herbal preparations ...

    African Journals Online (AJOL)

    Antibacterial activity of some powdered herbal preparations marketed in Kaduna metropolis. D Abba, H.I Inabo, S.E Yakubu, OS Olonitola. Abstract. The aim of the study was to investigate the phytochemical components and the antibacterial activities of some powdered herbal medicinal preparations sourced from identified ...