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Viktor D. Rud’ Tatyana N. Gal’chuk Alexander Yu. Povstyanoi 《Powder Metallurgy and Metal Ceramics》2005,44(1-2):88-92
A technology has been developed for improving the properties of ShKhl7 steel powder, obtained from bearing production waste sludge by familiar technological processes. On the basis of theoretical and experimental studies, we have ascertained the optimal conditions for ball milling, grinding, and heat treatment of the powders so as to improve their fluidity and bulk density. The technological and strength characteristics of the powders studied make them suitable for the production of serviceable parts by powder metallurgy methods.__________Translated from Poroshkovaya Metallurgiya, Nos. 1–2(441), pp. 106–112, January–February, 2005. 相似文献
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The extrusion dynamics of high-strength powder metallurgy composite materials was studied. The extrusion parameters for porous compacts of copper fibers and Cu ― Mo composites were optimized. It was shown that orientation of fibers is possible only when they are sufficiently widely dispersed in the powder matrix and also when the fiber length is much greater than its diameter l ≫ d. The mechanical properties of the composites was investigated. A practically pore-free structure was obtained at a degree of reduction λ = 4-6. With this the strengthening effect of fibers in the matrix was fully realized.
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Suren G. Agbalyan 《Powder Metallurgy and Metal Ceramics》2001,40(11-12):595-600
The extrusion dynamics of high-strength powder metallurgy composite materials was studied. The extrusion parameters for porous compacts of copper fibers and Cu ― Mo composites were optimized. It was shown that orientation of fibers is possible only when they are sufficiently widely dispersed in the powder matrix and also when the fiber length is much greater than its diameter l ? d. The mechanical properties of the composites was investigated. A practically pore-free structure was obtained at a degree of reduction λ = 4-6. With this the strengthening effect of fibers in the matrix was fully realized. 相似文献
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粉末冶金快速凝固技术与材料 总被引:8,自引:1,他引:8
以粉末冶金快速凝固技术和材料为线索,评述了快速凝固制粉技术的发展,材料特性以及在金属材料领域的应用,最终阐述了该领域的研究现状与发展前景。 相似文献
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Available information on the composition and methods of production of iron-based powder metallurgy wear-resistant materials is reviewed. It is shown that most developments in this field are based on the principle of obtaining wear-resistant material by the creation of a pseudoalloy with a clearly defined heterogeneous structure, in which the microhardnesses of the base material and a hard phase are substantially different. In addition to traditional methods, including pressing and sintering porous ingots and (in some cases) infiltration with a lower melting alloy, methods based on hot working sintered porous ingots under pressure have recently found wider application. 相似文献
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研究成型压力对铜基摩擦材料显微组织和性能的影响。结果表明,铜基摩擦材料的密度随成型压力的增加基本保持不变;随着成型压力的增加,孔隙率明显降低,致密度提高。当成型压力从60t增加到100t时,铜基摩擦材料的硬度明显提高,当成型压力继续增加时,硬度出现下降趋势;铜基摩擦材料的摩擦系数随着成型压力的增加呈先降低后增加的趋势。在成型压力为100t时,铜基粉末冶金摩擦材料的综合性能最佳。 相似文献
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We continue our review of the data in the literature on the development of compositions and a technology for the manufacture of iron-based wear-resistant sintered materials. Analysis of the data shows that methods based on hot working of sintered porous compacts by pressure (hot forging, extrusion, etc.) are suitable for producing high-quality wear-resistant materials with superior strength and operating characteristics when working under high loads. 相似文献
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To minimize the manufacturing costs of parts with specified operational properties, the machining processes must be optimized. Cutting accounts for at least 70% of such processes. To that end, tool materials with distinctive properties may be developed and utilized. Analysis of manufacturing components—in particular, power components in gas-turbine engines—shows the need for higher quality of the machined surfaces and more efficient use of expensive equipment with numerical and adaptive control systems, so as to ensure a wide range of cutting conditions, including high-speed cutting. To obtain products that are domestically and internationally competitive, we need to optimize cutting processes, in which the tool is the weakest link in the technological chain. Defects of the cutting tool impair the productivity and product quality. In the present work, the wear of cutting tools produced by the sintering of high-speed steel powder is studied. Tool materials based on high-speed steel with additional alloying by titanium carbide (carbide steel) are shown to be highly wear-resistant. They may be classified as a new category of self-organizing tool materials. The results indicate the expediency of additional alloying by two methods to modify the tool friction and wear: (1) alloying with compounds that considerably reduce the self-organization by decreasing the frictional coefficient at working temperatures; (2) alloying to expand the range of self-organization. Both methods result in lower frictional forces and temperatures, as confirmed by the change in wear resistance and frictional characteristics. The wear resistance of such tools is found to be 2–3.5 times that of regular high-speed steel tools. 相似文献
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The hightemperature strength and heat resistance of new powder metallurgy antifrictional materials based on the powder metallurgy nickel alloy É:P975 were investigated. The effect of alloying elements on the structure and properties of the new materials at high temperatures was studied. It is shown that the developed materials can be successfully used in friction units operating at temperatures up to 900°C in air. 相似文献
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L. J. B. Smith S. F. Corbin R. L. Hexemer Jr. I. W. Donaldson Donald Paul Bishop 《Metallurgical and Materials Transactions A》2014,45(2):980-989
The objective of this research was to design aluminum powder metallurgy (PM) alloys and processing strategies that yielded sintered products with thermal properties that rivaled those of the cast and wrought aluminum alloys traditionally employed in heat sink manufacturing. Research has emphasized PM alloys within the Al-Mg-Sn system. In one sub-theme of research, the general processing response of each PM alloy was investigated through a combination of sintering trials, sintered density measurements, and microstructural assessments. In the second, the thermal properties of sintered products were studied in detail. Thermal conductivity was first determined using a calculated approach through discrete measurements of specific heat capacity, thermal diffusivity, and density and subsequently verified using a transient plane source technique on larger specimens. Experimental PM alloys achieved >99 pct theoretical density and exhibited thermal conductivity that ranged from 179 to 225 W/m K. Thermal performance was largely dominated by the amount of magnesium present within the aluminum grains and, in turn, bulk alloy chemistry. Data confirmed that the novel PM alloys were highly competitive with even the most advanced heat sink materials such as wrought 6063 and 6061. 相似文献