摘要
3 mm thick 7050-T7451 aluminum alloy joint was obtained by friction stir welding, and the two-step aging treatment was performed at 121 ℃ × 5 h + 163 ℃× 27 h after welding. Microstructure, hardness profiles and stress corrosion sensitivity of the joint were measured and studied. The results indicate that through the two-step aging, the grain size is coarsened, the age-hardening precipitates and PFZ become wider at the same time, which results in the discontinuous grain boundary;the microhardness of the FSW joints decreased, but the heat-affected zone significantly narrowed, which increased the uniformity of the microhardness of the FSW joints;and the two-stage aging effectively reduced the stress corrosion sensitivity of the FSW joints. The joints with aging treatment were not broken after 60 days,however all the joints without aging treatment were broken within 1 day.
作者
Zhang Hua
Guo Qilong
Zhao Changyu
Lin Sanbao
Shi Gongqi
张华;郭启龙;赵常宇;林三宝;石功奇(School of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China;The Welding Institute,Cambridge CB216AL,UK)
基金
National Natural Science Foundation of China (51774047)
Beijing Great Wall Scholars Training Program(CIT&TCD20170309)。
