Powder Metallurgy Use of Waste from Bearing Production

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.     

Powder Metallurgy Composite Materials Strengthened with Fibers

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.

     

Powder Metallurgy Composite Materials Strengthened with Fibers

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.     

发展粉末冶金 节约金属材料

评述了当前我国粉末冶金工业的发展现状,阐述了节材主要方向和重点节材技术,并提出了今后开发粉末冶金新工艺、新材料的建议。     

粉末冶金纳米材料的制备与应用前景

介绍了粉末冶金纳米材料的几种制备方法,并展望了其应用前景。     

粉末冶金快速凝固技术与材料

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。     

《中国材料工程大典 粉末冶金材料工程》

《中国材料工程大典》是关于材料的结构和性能、制备和测试、成形和加工、热处理和表面工程的大型工具书，共26卷，近7000万字，是我国迄今为止篇幅最大、涵盖内容最为新颖、全面、丰富和权威的材料工程工具书。《中国材料工程大典》由化学工业出版社出版，2006年3月全套出齐。     

Powder Metallurgy Wear-Resistant Materials Based on Iron. Part 1. Materials Prepared by Sintering and Infiltration

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.     

TA7ELI粉末冶金材料力学性能与显微组织

以TA7 ELI钛合金棒为原料,用等离子旋转电极工艺制备出高品质钛合金球形粉末.采用热等静压成形工艺,将粉末压制成钛合金材料,并研究了材料的组织和力学性能.结果表明:等离子旋转电极工艺制备的钛合金球形粉末具有非常高的球形度和振实密度,粒度分布比较窄,非金属夹杂含量非常低;热等静压制备的低温钛合金达到全致密,其组织均匀细...     

粉末冶金电触头材料

本文评述了粉末冶金法制遣的、用于强电开关电器的电触头材料,包括各种材料的发展过程、特点、用途以及最近的发展倾向。     

成型压力对铜基粉末冶金摩擦材料性能的影响

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。     

Powder Metallurgy Wear-Resistant Materials Based on Iron. Part 2. Materials Hot-Pressed from Porous Compacts

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.     

Properties of a Tool Produced by Powder Metallurgy

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.     

粉末冶金法制备TiAl基合金

综述了粉末冶金制备TiAl基合金的几种方法，其中包括机械合金化，自蔓延高温合成、反应烧结及预合金粉末法等，同时论述了上述方法的局限性和发展趋势。     

Strength and Heat Resistance of New Antifrictional Powder Metallurgy Materials Based on Nickel

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.     

Development and Processing of Novel Aluminum Powder Metallurgy Materials for Heat Sink Applications

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.