等径道角挤压工艺对铸态 AZ91D 镁合金组织的影响

摘要

目的：介绍等径道角挤压的原理及其对铸态 AZ91D 镁合金的组织产生的作用。方法通过确定的试验工艺参数,对 AZ91D 镁合金进行了等径道角挤压变形试验。使用金相显微镜和扫描电镜(SEM),对变形前后的材料进行了显微组织的观察。结果通过进行 ECAE 挤压后,AZ91D镁合金中的黑色共晶相(Mg17 Al12)产生了回溶,在机械剪切和动态再结晶的综合作用下,晶粒得到了细化。结论通过等径道角挤压,能明显改善铸态 AZ91D 镁合金的组织。%Objective To introduce the principle of equal channel angular extrusion(ECAE)and analyze its effect on the microstructure of AZ91D magnesium alloy. Methods The ECAE experiment of AZ91D magnesium alloy was conducted u-sing the designated process parameters. The microstructure of AZ91D magnesium alloy before and after equal channel angu-lar extrusion was investigated by means of optical metalloscopy and scanning electron microscope equipment. Results The results showed that the black eutectic phase (Mg17 Al12 ) began to remelt after ECAE treatment, and the crystals were re-fined under the comprehensive effects of mechanical shear and dynamic recrystallization. Conclusion The microstructure of AZ91D magnesium alloy was obviously improved by ECAE.