预时效对Al-5.2Mg-0.45Cu-2.0Zn合金室温稳定性的影响  

Effect of Pre-aging Treatment on Room Temperature Stability of Al-5.2Mg-0.45Cu-2.0Zn Alloy Sheet

作　　者：曹城 张迪[2] 庄林忠[2,3] 张济山 刘嘉斌[1] Cao Cheng;Zhang Di;Zhuang Linzhong;Zhang Jishan;Liu Jiabin(Zhejiang University,Hangzhou 310027,China;State Key Laboratory of Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China;Tata Steel,1970 CA Ijmuiden,Netherlands)

机构地区：[1]浙江大学,浙江杭州310027 [2]北京科技大学新金属材料国家重点实验室,北京100083 [3]塔塔钢铁,荷兰艾默伊登1970CA

出　　处：《稀有金属材料与工程》2020年第4期1166-1170,共5页Rare Metal Materials and Engineering

基　　金：National Key Research and Development Program of China(2016YFB0300801);National Natural Science Foundation of China(51571013,51301017)。

摘　　要：研究了预时效对Al-5.2Mg-0.45Cu-2.0Zn合金时效析出行为的影响。结果表明:预时效不仅提高了合金的室温稳定性,避免了合金烤漆软化,同时提高了合金的烤漆时效响应速度。合金经T4处理后,再峰时效处理后的组织包括粗大的T-Mg32(AlZn)49相以及针状的S-Al2MgCu相。然而合金经T4P处理后,再峰时效处理的组织只含有细小而高密度的T-Mg32(AlZn)49相而不包括S-Al2MgCu相。自然时效后不稳定的原子团簇在180℃时效后会回溶到基体中,从而抑制了合金的时效析出强化。而预时效后生成的稳定的原子团簇会成为180℃时效的形核点,显著提高了合金的时效响应速度。Pre-aging treatment was performed on Al-5.2Mg-0.45Cu-2.0Zn alloy.Results show that pre-aging treatment not only improves the stability of the alloy sheet at room temperature and avoids the paint-baking softening,but also enhances the age hardening response during subsequent artificial aging at 180℃.The microstructure of the T4 sample in peak aged condition consists of coarse lath-like T-Mg32(Al,Zn)49 phase and needle-like S-Al2MgCu phase.However,the microstructure of the T4P sample in peak aged condition only consists of high density of finer and equiaxed T phase and S phase disappears.Unstable clusters formed during natural aging dissolve when imposed at 180℃,which retards the precipitation process of the alloy.Stable clusters formed during pre-aging treatment serve as the nuclei of the T phase during aging at 180℃,which enhances the age hardening response of the alloy.

关 键 词：铝合金 相变 透射电镜 

分 类 号：TG156.92[金属学及工艺—热处理] TG146.21[金属学及工艺—金属学]