粉末冶金法制备AZ91镁合金的组织及热性能

Microstructure and thermal property of AZ91 magnesium alloy prepared by powder metallurgy

采用粉末冶金方法制备了AZ91镁合金,研究了烧结温度对合金的致密度和热导率的影响规律,并对烧结样品的物相和显微组织进行了分析.研究发现,AZ91镁合金的最佳烧结温度为610℃,致密度可以达到97.4%,实验条件下所获得的最高热导率可达到63.1W.m-1.K-1.X射线衍射和扫描电子显微镜结果分析表明,烧结合金组织主要由α-Mg固溶体和β-MgAl相两相组成,其中β-MgAl相表现出离异共晶β相和非连续析出β相两种主要存在形态.

AZ91 magnesium alloy was fabricated by powder metallurgy. The effects of sintering temperature on the relative density and thermal conductivity were investigated. The microstructure of the material was observed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The result shows that the best sintering temperature is 610 12. At this sintering temperature the relative density can reach 97.4 % and the highest thermal conductivity can be up to 63.1 W· m^- 1· K^- 1. The sintering microstructure of the alloy is composed of α-Mg solid solution matrix and β-Mg17Al12. The β phase exhibits two main forms, i.e., divorced eutectic 13 phase and discontinuous precipitated β phase.