固溶工艺对挤压铸造稀土镁合金组织和性能的影响

采用挤压铸造制备Mg-Nd-Gd-Zr镁合金试样。对该合金分组T6热处理后发现,固溶温度由510℃增至540℃过程中,抗拉强度呈先升后降趋势,伸长率持续下降。530℃固溶温度下固溶时间由8 h延长至20 h,合金晶粒长大明显,但伸长率增加100%。SEM分析表明,不同温度固溶处理后合金拉伸断口有区别,510℃固溶处理后断口由残留相开裂和穿晶解理开裂面构成,530℃固溶处理后断口以准解理穿晶断裂为主。

Influence of solution process on the microstructure and mechanical properties of squeeze casting Mg-BE alloy

Mg-Nd-Gd-Zr alloy was prepared by squeeze casting.The effect of solution temperature and solution time of heat treatment on the property of the alloy Was studied.The results show that.with the solution temperature increasing from 510℃ to 540℃,the ultimate tensile strength(UTS)increased firstly and then decreased,and the elongation rate reduced continuously.When the solution time Was prolonged from 8 h to 20 h,the grain grew up obviously,while the elongation rate increased by 100%.SEM scanning analysis of the fracture surface shows that,after heat treatment at 510℃,the fracture surface of experimental alloy was made up of cracked section of the retained phase and transcrystalline fracture,while at 530 ℃,quasi-cleavage fracture is the main feature.