Effect of post-weld heat treatment on microstructure and mechanical properties of welded joints of 6061-T6 aluminum alloy

作     者：Jie YI Guan WANG Shi-kang LI Zhi-wen LIU Yan-li GONG 易杰;王冠;李世康;刘志文;龚艳丽

作者机构：College of Mechanical EngineeringHunan Industry PolytechnicChangsha 410208China State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyHunan UniversityChangsha 410082China Qiuzhen CollegeHuzhou UniversityHuzhou 313000China College of Mechanical EngineeringUniversity of South ChinaHengyang 421001China 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2019年第29卷第10期

页      面：2035-2046页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：Projects(2019JJ70077,2019JJ50510) supported by the National Science Foundation of Hunan Province,China Project(31665004) supported by Open Fund of State Key Laboratory of Advanced Design and Manufacture for Vehicle Body,China Projects(18B552,18B285) supported by Scientific Research Fund of Hunan Provincial Education Department,China 

主　　题：6061 aluminum alloy double-pulsed MIG welding post-weld heat treatment microstructure evolution mechanical property 

摘      要：6061 aluminum alloy T-joints were welded by double-pulsed MIG welding process. Then, the post-weld heat treatment was performed on the welded T-joints. The weld microstructure under different aging temperature and time was investigated by transmission electron microscopy and scanning electron microscopy. The mechanical properties were examined by hardness test and tensile test. The results showed that the micro-hardness was sensitive to heat treatment temperature and time. Increasing temperature was beneficial to the shortening of peak aging time. There were a large number of dislocations and few precipitates in the welded joints. With the increase of post-weld heat treatment temperature and time, the density of dislocation decreased. Meanwhile, the strengthening phase precipitated and grew up gradually. When the post-weld heat treatment temperature increased up to 200℃, large Q phases were observed. And they were responsible for the peak value of the micro-hardness in the welded joints.