双级时效对7A52铝合金组织与性能的影响  

Effects of duplex ageing conditions on microstructures and properties of 7A52 alloy

作　　者：黄继武[1] 尹志民[1] 聂波[1] 方家芳[1] 陈继强[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2007年第6期1045-1049,共5页Journal of Central South University:Science and Technology

基　　金：民口配套项目(MKPT-05-302)

摘　　要：采用拉伸力学性能测试、电导率测定、透射电镜分析等手段研究双级时效处理条件下7A52铝合金的力学性能、电导率和显微组织结构。研究结果表明:7A52铝合金适宜的双级时效工艺为105℃/8 h+130℃/14 h。在此条件下,合金的抗拉强度、屈服强度、伸长率和电导率分别为500 MPa,444 MPa,11.1%和18.44 S/m。与单级峰值时效相比,强度并未明显降低而电导率有明显提高,表明合金抗应力腐蚀性能得到改善。双级时效后,合金的晶内组织为细小弥散分布的η′(MgZn2)相,晶界上有断续分布的晶界析出相MgZn2和较明显的无沉淀析出带。The effects of duplex aging conditions on the microstructures, mechanical properties and electrical conductivity of the 7A52 aluminum alloy were investigated by means of tensile, conductivity measurement and transmission electron microscopy, The results show that the tensile strength, yield strength, specific elongation and electrical conductivity of the alloy are 500 MPa, 444 MPa, 11.1% and 18.44 S/m, respectively after duplex aging （105 ℃/8 h＋130 ℃/14 h）, Compared with single step aging, the strength decreases little but the conductivity increases obviously, which illuminates that the stress corrosion resistance of the alloy improves after duplex aging. The precipitations of η＇（MgZn2） appear on grain interior, the discontinuous distribution of MgZn2 phase and the precipitated-free zones （PFZ） appear on the grain boundaries.

关 键 词：7A52铝合金 双级时效 显微组织 电导率 性能 

分 类 号：TG249.9[金属学及工艺—铸造]