The mechanical properties of the 7xxx series aluminum alloy deposited specimens are low due to the uneven microstructure and element segregation in the process of wire and arc additive manufacturing (WAAM). In order to solve this problem, the 7075 aluminum alloy thin-walled specimens deposited by WAAM were subjected to solid solution + artificial aging heat treatment (T6 state). The microstructure evolution and mechanical properties before and after heat treatment were investigated. The results showed that the grains in the as-deposited specimen were surrounded by eutectics with network-like structure, and the elements of Zn, Mg and Cu were concentrated at the grain boundaries, resulting in the element segregation. After T6 heat treatment, most of the eutectics were dissolved. Moreover, the unevenness of the element distribution was significantly reduced. Compared with the as-deposited specimens, the tensile strength and elongation of T6 specimens were improved. The value of tensile strength increased from (279.4 ± 5.3)MPa to (493.9 ± 10.2)MPa, and the elongation increased from 3.78 %± 0.35% to 9.66% ± 1.70%. The tensile fracture surface of T6 specimen was densely covered with dimples. Therefore, the fracture mode was ductile fracture.
马广义，刘德华，师敬桉，王儒政，牛方勇，吴东江. 电弧增材制造7075铝合金的微观组织与力学性能[J]. 航空制造技术, 2022, 65(1/2): 14-19.
MA Guangyi, LIU Dehua, SHI Jing’an, WANG Ruzheng, NIU Fangyong, WU Dongjiang. Microstructure and Mechanical Properties of 7075 Aluminum Alloy Prepared by Wire and Arc Additive Manufacturing. Aeronautical Manufacturing Technology, 2022, 65(1/2): 14-19.