储存能对纯金属粉末烧结过程的影响

为了研究冷压和加热方式对烧结过程的影响,利用高温光学显微镜对Al-Mg和Al-Cu等二元合金体系进行了原位烧结观察。结果表明:加热方式和压制力对烧结速度都有很大影响。在最高温度相同的情况下,单一温度烧结比分阶段烧结时颗粒熔融速度要快得多;烧结前的退火工艺大大延缓了烧结进程;在一定范围内提高冷坯成型时的压制力能明显提高烧结速度。进一步分析表明储存能是造成以上结果的直接因素,合理利用储存能成为提高烧结效率的一条重要途径。试验的结果为优化现有粉末冶金工艺提供了直接的试验依据。

Effect of stored energy on sintering process of pure metal powders

In order to study the influence of cold pressing and heating mode on sintering, a high temperature optical microscope was employed to in-situ observe the sintering process of Al-Mg and Al-Cu elementary powders systems. The results showed that they all affected sintering rate to a great extent. The melting rate of particles when isothermal sintering was much faster than that when staged sintering under the same maximum temperature. The annealing treatment before sintering could greatly slow sintering process. In a certain range, sintering rate could increase with the compacting pressure level increasing. Further analysis suggested that stored energy when cold compacting was the reason of the above results, and the appropriate using of stored energy could be an important way to enhance sintering efficiency. These results would provide direct experience basis to optimize the present powder metallurgy routines.