预变形对AZ80镁合金孪晶演化及力学性能的影响  

Effect of pre-deformation on twins evolution and mechanical properties for AZ80 magnesium alloy

作　　者：王阿蒙 刘娟[1] 赵杰[1] 章海明[1] 崔振山[1] WANG A-meng;LIU Juan;ZHAO Jie;ZHANG Hai-ming;CUI Zhen-shan(Institute of Forming Technology&Equipment,Shanghai Jiao Tong University,Shanghai 200030,China)

机构地区：[1]上海交通大学塑性成形技术与装备研究院,上海200030

出　　处：《塑性工程学报》2021年第11期124-130,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51635005)。

摘　　要：针对热挤压态AZ80镁合金材料,进行了预变形量为1%、2%、4%和6%的室温压缩,再通过沿挤压方向的拉伸试验和变形前后的EBSD分析,研究了预变形对AZ80镁合金的微结构、变形机制以及力学性能的影响。由镁合金的孪生机制分析得出,在AZ80镁合金压缩过程中,除发现极少数{1011}压缩孪晶和{1012}-{1012}二次孪晶,主要以{1012}拉伸孪晶为主导,并观察到多种关系的孪晶变体和晶间孪晶对。统计结果表明,孪晶界数量随变形量的增大呈现先增后减的趋势,且变形量越大、孪晶比例越高,试样的伸长率越高。变形量为6%的试样经拉伸后,抗拉强度和伸长率分别提高至349.03 MPa和10.79%,较未预变形试样增加了7.23%和27.5%,具有较好的综合力学性能。For hot-extruded AZ80 magnesium alloy,compression with the reduction of 1%,2%,4% and 6% at room temperature was conducted.Then,tensile tests along the extrusion direction and EBSD analysis before and after deformation were performed,and the effects of pre-compression on microstructure,deformation mechanism and mechanical properties of AZ80 magnesium alloy were investigated.Through analysis of twining mechanism of magnesium alloy,it is found that most{1012}tensile twins are found except very few{1011}compression twins and{1012}-{1012}secondary twins during compression process of AZ80 magnesium alloy.Moreover,multiple twin variants and intergranular twin pairs were observed.Statistics results show that with the increase of deformation,the number of twin boundaries increases first and then decreases.The larger the deformation,the higher the ratio of twin fraction,the higher the elongation.The specimen with the reduction of 6% shows the tensile strength and elongation of 349.03 MPa and 10.79% respectively,which are7.23% and 27.5% higher than those of the non-compressed specimen respectively,showing good comprehensive mechanical properties.

关 键 词：镁合金AZ80 预变形 孪晶 退孪生 加工硬化 力学性能 

分 类 号：O344[理学—固体力学] TG146[理学—力学]