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Structural Changes and Sintering Characteristics of Copper-Lead Alloys by Mechanical Grinding Treatment

机械研磨处理铜铅合金的组织变化及烧结特性

基本信息

批准号：
04650630
负责人：
OHASHI Teruo
金额：
$ 1.22万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Effect of mechanical grinding (MG) on the sintered structures and sintering characteristics of the Cu-Pb alloys has been investigated by dilatometric measurements and structural observations. It was shown that the structures of the alloys powders which were sufficiently pulverized by a a ball-milling of high energy type were composed from the crystallites the diameter of which was more or less than 50nm. The resultant redistribution of Pb in the copper matrix could be so accepted that the sintered compacts of these powders improved wear resistance. A distinctive dilatometric change was observed during isochronal sintering these MG powders in hydrogen atmosphere. Two peaks were observed in the dilatation curves, the first at 673K, the second at 973K.Sintering proceeded above the second peak temperature with a shrinkage in volume, the amount of which increased with increasing MG time.Sintering mechanism has been also discussed in viewing the isothermal sintering behaviors of MG powders. During sintering the expansion preceded the shrinkage in the powder compact volume. The copper particles grew according to the cube root of time followed by a shrinkage in volume of the powder compacts. Activation energies for the particle growth were estimated to be 85, 173 and 230kj/mol for the powder compacts of MG time's 0 hr, 6 hr and 20 hr, respectively. It was suggested such a difference in the activation energy is due to the morphology of the copper partices which was affected by MG treatment.

通过金相测量和结构观察，研究了机械研磨对Cu-Pb合金烧结组织和烧结特性的影响。结果表明，经高能球磨充分粉碎的合金粉末，其结构由直径大于或小于50 nm的晶粒组成。铅在铜基体中的重新分布可以被接受，这些粉末的烧结体提高耐磨性。在氢气气氛中等时烧结时，观察到了明显的电阻率变化。膨胀曲线出现两个峰值，第一个峰值出现在673 K，第二个峰值出现在973 K，在第二个峰值温度以上，烧结发生收缩，收缩量随MG时间的增加而增加，结合MG粉末的等温烧结行为，探讨了MG粉末的烧结机理。在烧结过程中，膨胀先于粉末压坯体积的收缩。铜颗粒根据时间的立方根生长，随后是粉末压块的体积收缩。对于MG时间为0小时、6小时和20小时的粉末压坯，颗粒生长的活化能分别为85、173和230 kJ/mol。这表明，这种差异的活化能是由于铜颗粒的形态，这是由MG处理的影响。