高温预析出对Al-Zn-Mg铝合金组织、力学性能和应力腐蚀性能的影响  

Effect of high-temperature pre-precipitation on microstructure, mechanical property and stress corrosion cracking of Al-Zn-Mg aluminum alloy

作　　者：黄兰萍[1] 陈康华[1] 李松[1] 刘红卫[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《中国有色金属学报》2005年第5期727-733,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50471057);国家武器装备预先研究资助项目(41312020205)

摘　　要：研究了近固溶度高温预析出工艺对抗应力腐蚀性能较差的中强可焊7A52和仿7039合金的组织、时效硬化和应力腐蚀性能的影响。显微组织观察、力学性能分析及应力腐蚀性能测试结果表明近固溶度高温预析出处理可使合金在晶界形成不连续的析出相;在保持合金强度、塑性的同时,预析出可提高抗应力腐蚀性能,但预析出温度过低,合金强度呈下降趋势;固溶后于400℃预析出处理在峰值时效状态下可使7A52铝合金强度和抗应力腐蚀性能得到最佳组合,抗应力腐蚀性能达到三级时效后的效果。The effects of near-solvus high-temperature pre-precipitation on the microstructure, age hardening and stress corrosion cracking of 7A52 and quasi 7039 aluminum alloys were investigated. After analyzed by optical and transmission electron microscope, it is shown that the near-solvus ~pre-precipitation can be limited to grain boundary and can enhance the discontinuity of grain boundary precipitates in the sequent age. The stress corrosion cracking resistance can be improved with non-deteriorated strength and plasticity via the high-temperature pre-precipitation. The optimum combination of strength and stress corrosion cracking resistance in peak-aging temper can be obtained for 7A52 alloy after pre-precipitation treatment at 400℃. The stress corrosion cracking resistance at peak-aging temper can match the same effect with retrogression and ~re-aging Treatments by the high-temperature pre-precipitation.

关 键 词：AL-ZN-MG合金 近固溶度预析出 组织 力学性能 应力腐蚀性能 

分 类 号：TG249.9[金属学及工艺—铸造]