Al-10Mg二元合金系烧结过程的原位观察

烧结是粉末冶金工艺中至关重要的一环,为了加强对烧结过程的直观认识,利用高温光学显微镜(HTOM)对Al-10Mg的二元纯金属粉末体系进行了烧结的原位观察试验,发现该体系烧结的典型物理过程是:镁颗粒边界熔化,镁晶界熔化,最后为镁颗粒熔化;镁颗粒熔化进程不同步;当烧结温度超过某一临界温度Tc时,镁颗粒迅速熔化;而且烧结速度随冷坯密度的提高而加快,这为进一步合理优化烧结工艺提供了直接的参照依据.

In-Situ Investigation of the Sintering Process of Al and Mg Binary Alloy System

Sintering is one of the most important steps for powder metallurgy (PM). In order to observe the sintering process directly, a high temperature optical microscope (HTOM) was used to in-situ investigate the Al and Mg binary alloy system with a weight ratio of 9:1. A typical physical evolving character was found in this system. The melting process of magnesium particles is not synchronous, first from the particle border, then in the grain boundary, and last into the whole magnesium particle. When sintering temperature is above a critical temperature Tc, the magnesium particle melts in a very short time, and the sintering rate is accelerated with the increasing of the cold compact density. These experiment results afford a direct reference to the sintering routine optimization.