(1. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410083；
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要:
关键字: 7050铝合金；回归时间；力学性能；晶间腐蚀
（1. Educational Key Laboratory of Non-Ferrous Metal Materials Science and Engineering, Central South University, Changsha, 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of retrogression time on the mechanical properties and intergranular corrosion (IGC) resistance of 7050 aluminum alloy were investigated by means of hardness and electrical conductivity test, optical microscopy (OM) and transmission electron microcopy (TEM). The results show that the highest yield strength and IGC resistance are obtained by 190 ℃/60 min retrogression and reaging. But when the alloy is treated near the lowest value of hardness curve of retrogression, the lowest IGC resistance is gotten by 190 ℃/4 min retrogression treatment. The TEM observation shows that the grain boundary precipitates are continuous and coarse by 190 ℃/4 min retrogression treatment, and no obvious precipitate free zone (PFZ) is observed. With retrogression time increasing, more spaced and coarser grain boundary precipitates are observed, and the PFZ becomes wider, which can attribute to improve IGC resistance of 7050 aluminum alloy.
Key words: 7050 aluminum alloy; retrogression time; mechanical properties; intergranular corrosion
