国外粉末冶金铝合金的研究近况

本文综述了国外粉末冶金合金的发展过程,粉末冶金铝合金的强化机理,几种新型铝合金:高强铝合金,高比强度、高比刚性率铝合金,耐高温、高强铝合金,功能铝合金和再生铝合金及其应用。     

美国肯纳公司近况及其它公司粉冶新工艺

介绍了肯纳公司及其它公司的概况、新产品及其新工艺。     

钼及其合金的高温应用

评述了钼及其合金在高温下的一些最重要的工业应用.     

用作真空烧结炉发热体的高温钼板材

叙述了用作真空烧结炉发热体的高温钼（HTM）合金板从制粉到轧制成0．5mm板材的工艺过程；对乳制成的0．5mm厚的板材在不同温度退火后的试样进行了室温拉伸、塑－脆转变温度（DBTT）及反复弯曲性能的测定，同时检验了1200～1400℃的高温拉伸性能，并用金相法观察了温度对高温钼合金板的显微组织的影响，还用扫描电镜对高温钼粉末形貌、烧结坯断口、室温拉伸及高温拉伸断口进行了观察。最后简介了这种钼合金板的使用情况。     

钼及其合金的最新发展

本文评述了世界钼及其合金的一些最新发展。     

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。     

Microstructure and mechanical properties of PM Ni56Fe19Al25 alloy

Abstract

Scanning electron microscopy and X-ray diffraction analysis were used to study microstructure and mechanical properties of PM Ni₅₆Fe₁₉Al₂₅ alloy. The results indicate that as sintered specimen is (β+γ) dual phase structure, and its density is 6·54 g cm^?3 (the relative density is 94·0%), tensile strength is 771 MPa and the total strain is 4·3%. As quenched specimen presents a large superelasticity with the maximum recovery strain of 4·5%, and its tensile strength is 850 MPa and the total strain is 9·2%. The fracture modes of Ni₅₆Fe₁₉Al₂₅ alloy is transgranular, intergranular and tough mixed type.     

短碳纤维增强铜合金复合材料的摩擦磨损机理研究

采用冷压烧结方法制备了碳纤维增强铜合金复合材料(Cf/Cu-Sn-Zn)和ZQSn663锡青铜.对摩擦磨损性能进行了对比研究,并对磨损机理进行了讨论.实验结果表明,Cf/Cu-Sn-Zn复合材料的磨损率和摩擦系数低于ZQSn663锡青铜.当碳纤维体积含量达到12%时,复合材料的摩擦磨损性能达到最佳.SEM和EDS分析结果表明,ZQSn663锡青铜的磨损机制主要是黏着磨损.Cf/Cu-Sn-Zn复合材料的磨损是黏着磨损和氧化磨损共同作用的结果.     

三十年沧桑巨变——庆祝重庆冶炼厂粉末冶金分厂建厂三十年

简单介绍了重庆冶炼厂粉末冶金分厂建厂三十年来的巨大变化。     

粉末冶金发展现状及趋势

文章评述了粉末冶金技术在机械零件、摩擦材料、电工材料、硬质合金、难熔金属材料、金刚石—金属工具、航空结构材料、非晶态合金、精细陶瓷、功能材料等领域国内外的研究开发现状及新工艺等的发展趋势。     

Fabrication of micro-fine spherical Ti–6Al–4V alloy powders based on hydrogen decrepitation and plasma spheroidisation

A novel process was developed for scalable fabrication of micro-fine spherical Ti–6Al–4V alloy powders. The hydrogenation-treated Ti–6Al–4V alloy ingot was mechanically crushed into particles and then sieved into three size grades. The powders were separately sent through the radio frequency (RF) argon plasma system for spheroidisation. The fabrication process and powder characteristics were investigated. The results indicate the alloy ingot upon hydrogenation treatment can be efficiently crushed into fine particles with size of 5–76?μm. During RF plasma processing, the powders are found to be greatly refined due to hydrogen decrepitation with subsequent transformation into spherical morphology. The effect of hydrogen decrepitation on particle refinement is impaired with decreasing particle size of feed powders. The spherical powders exhibit a narrow particle size distribution and the average size is in the range of 8.2–27.9?μm. The spheroidised powders mainly consist of β-Ti and TiH_1.5.     

Solid state sintering and consolidation of Al powders and Al matrix composites

As an attempt to depart from conventional transient liquid phase sintering practice, solid state vacuum sintering was studied in loose powder and in hot quasi-isostatically forged samples composed of commercial inert gas atomized (CIGA) or high purity Al powder. The high purity Al powder was generated by a gas atomization reaction synthesis (GARS) technique that results in spherical powder with a far thinner surface oxide. After vacuum sintering at 525 °C for up to 100 h, SEM results showed that the GARS Al powder achieved significantly advanced sintering stages, compared to the CIGA Al powder. Tensile results from the forged samples also showed that although its ultimate tensile strength is lower, 95 vs. 147 MPa, the ductility of the GARS pure Al sample is higher than the CIGA Al sample. Forging also consolidated a model powder-based composite system composed of an Al matrix reinforced with quasi-crystalline Al–Cu–Fe powders, where the same powder synthesis methods were compared. Auger surface analysis detected evidence of increased matrix/reinforcement interfacial bonding in the composite sample made from GARS powder by alloy interdiffusion layer measurements, consistent with earlier tensile property measurements. The overall results indicated the significant potential of using Al powders produced with a thin, high purity surface oxide for simplifying current Al powder consolidation processing methods.     

轿车用40kN千斤顶粉末冶金圆锥齿轮

介绍了用粉末冶金Fe－Cu－C渗铜结构材料制造轿车用40kN千斤顶圆锥齿轮的工艺过程，原材料和各工序的技术要求。     

球磨工艺对铜基摩擦材料混合料的影响Ⅰ:对粒度分布的影响

采用单因素试验方法,研究了行星式球磨工艺参数如球料比、球磨时间、磨球直径、醇料比等对铜基粉末冶金摩擦材料混合料粒度分布的影响规律。结果表明,随球料比的增加,混合料的平均粒径不断减小,球料比为15∶1时,混合料的平均粒径最小,为1.345μm;球磨时间对混合料平均粒径的影响规律是随着球磨时间的增加混合料平均粒径先减小后增大;一定范围内的醇料比在湿磨过程中对研磨效率影响不大;相比于刚玉磨球,钢质磨球对于混合料的研磨效率更好。     

国外氮基烧结气氛的发展状况及应用实例

综述了国外氮基烧结气氛的发展状况。分析了氨基气氛的种类、优点以及对气氛组成的选择。列举了氨基烧结气氛的某些应用实例。     

现代铝合金焊接技术

综述了近年来世界各国新研制的和已在实际生产中广泛应用的现代铝合金焊接技术,并对每项合金焊接技术都从基本概念、原理、特点以及国内外的研究现状等方面做了较为详细的介绍。     

几种有色金属粉末的生产技术

本文介绍了铝粉、钛粉、铜粉、钼粉及铼粉制造技术的进展、典型的生产及应用情况。     

Ce添加量对Fe-2.4C-17Cr-1.8Mo-1.0Cu合金性能的影响

稀土元素的加入对材料的力学性能产生极大的影响,适当的加入量可以起到提高烧结制品性能的作用,但过多的加入量会恶化其性能。稀土元素Ce的最佳加入量为0.4%。     

Recyclability assessment of Al 7075 chips produced by cold comminution and consolidation using spark plasma sintering

A solid-state recycling route for processing aluminium alloy 7075 chips is proposed. This process involves pulverizing the chips using an industrial scale comminution line to produce a broad particle size distribution of granulated products and powders. Upon sieving, the ?140 mesh fraction of the pulverised material was consolidated by spark plasma sintering into fully dense compacts, i.e. >99%. The properties of the pulverised powders and compacts were compared to commercially available aluminium alloy 7075 powder used in industrial press-sinter applications. The comminution line produced powder particles which possessed a 7·9?±?0·6-nm thick native oxide layer with adhering exogenous contaminants, and aluminium oxide particles dispersed throughout the powder. The presence of the oxide layer and exogenous contaminants was found to be deleterious to the powder consolidation and mechanical properties. A flexural strength and strain and hardness of 94·7?±?7·2?MPa, 2·1?±?0·3% and 69·3?±?5·2 HV were obtained, respectively.