固溶工艺对AZ61-RE镁合金显微组织和力学性能影响  

Effects of Solution Technology on Microstructure and Mechanical Properties of AZ61-RE Magnesium Alloy

作　　者：付伟 程永奇[1] 施斌卿 张鹏[1] FU Wei;CHENG Yongqi;SHI Binqing;ZHANG Peng(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学材料与能源学院,广东广州510006

出　　处：《热加工工艺》2021年第18期133-138,共6页Hot Working Technology

基　　金：广东省应用型科技研发专项项目(2015B090926006);广东省公益研究与能力建设项目(2016A010103032,2014A010105043)。

摘　　要：在AZ61镁合金中添加了少量富Ce混合稀土元素,重点研究了固溶工艺对新型AZ61-RE合金的微观组织和力学性能的影响规律。结果表明:AZ61-RE镁合金铸态组织主要由α-Mg基体、沿晶界网状分布Mg_(17)Al_(12)相、花瓣状的Al_(10)RE_(2)Mn相、块状的Al_(11)RE_(4)相组成。随固溶温度(350~450℃)升高及保温时间(3~12 h)延长,Mg_(17)Al_(12)相不同程度地溶解于基体中,但稀土相几乎不变;显微硬度呈逐渐减小的趋势,屈服强度和抗拉强度呈逐渐减小的趋势,但断裂伸长率变化不大,这应与固溶处理后残留的稀土相处易萌生微裂纹有关。拉伸试样断口形貌表明,铸态和固溶处理后材料断裂模式均表现为韧脆混合型断裂特征。A small amount of Ce-rich mixed rare earth elements was added to AZ61 magnesium alloy.The effects of solid solution technology on the microstructure and mechanical properties of the new AZ61-RE alloy were studied.The results show that,the cast structure of the AZ61-RE magnesium alloy is mainly composed ofα-Mg matrix,Mg_(17)Al_(12)phase distributed along the grain boundary,petal-like Al_(10)RE_(2)Mn phase,and block-shaped Al_(11)RE_(4)phase.With the increase of solid solution temperature(350-450℃)and holding time(3-12 h),the Mg_(17)Al_(12)phase is dissolved in the matrix to some extent,but the rare earth phase is almost the same,the microhardness is gradually reduced,the yield strength and the tensile strength are gradually reduced.However,the elongation after break does not change much,which should be related to the residual rare earth phase after solution treatment,which is easy to initiate micro-cracks.The fracture morphology of tensile specimens shows that,the fracture modes of both cast and solution-treated materials show the characteristics of ductile-brittle mixed fracture.

关 键 词：镁合金 稀土镁合金 固溶处理 力学性能 

分 类 号：TG166.4[金属学及工艺—热处理]