(1. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要:
關(guān)鍵字: 7050鋁合金；回歸時(shí)間；力學(xué)性能；晶間腐蝕
（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
