AZ31镁合金双轴肩搅拌摩擦焊接头组织及性能  

Microstructure and properties of bobbin tool friction stir welding joint of AZ31 magnesium alloy

作　　者：吕东泽 刘威[1] 李于朋[1] LYU Dongze;LIU Wei;LI Yupeng(Key Laboratory of Advanced Structrural Materials,Ministry of Education,Changchun University of Technology,Changchun 130012,China)

机构地区：[1]长春工业大学教育部先进结构材料重点实验室,吉林长春130012

出　　处：《长春工业大学学报》2022年第6期652-657,共6页Journal of Changchun University of Technology

基　　金：吉林省科技厅重点研发项目(20220201031GX)。

摘　　要：采用双轴肩搅拌摩擦焊对4 mm厚AZ31镁合金进行焊接,分析了焊接接头热循环特性、组织及力学性能。结果表明,后退侧各点温度均高于前进侧,温度差值约为10℃。焊核区发生动态再结晶形成均匀的等轴晶,热机影响区组织为等轴晶。焊接接头显微硬度整体呈“W”型,热机影响区与焊核区交界处硬度最低为54 HV。接头平均抗拉强度为189 MPa,约为BM的92%,断裂方式为韧脆混合断裂。In this paper,4mm thick AZ31 magnesium alloy was welded by the bobbin tool friction stir welding.The thermal cycling characteristics,organization and mechanical properties of the welded joint were analyzed.The results show that the temperature at all points on the retreating side is higher than the advancing side,with the temperature difference of about 10℃.Dynamic recrystallization occurs in the stir zone to form uniform equiaxial crystals,and the thermos-mechanically affected zone is organized as equiaxed crystals.The overall microhardness of the welded joint is"W"type.Minimum hardness of 54 HV at the joint of the thermos-mechanically affected zone and the stir zone.The average tensile strength of the joints is 189 MPa,about 92%of BM,and the fracture mode is mixed ductile-brittle fracture.

关 键 词：AZ31镁合金 双轴肩搅拌摩擦焊 热循环曲线 微观结构 力学性能 

分 类 号：TG453.9[金属学及工艺—焊接]