Synergetic effect of natural ageing and pre-stretching on the ageing behavior in Tʹ/ηʹ phase-strengthened Al-Zn-Mg-Cu alloys  

作　　者：Yan Zou Lingfei Cao Xiaodong Wu Songbai Tang Mingxing Guo 

机构地区：[1]Engineering Research Center for Waste Oil Recovery Technology and Equipment,Ministry of Education,Chongqing Technology and Business University,Chongqing 400067,China [2]International Joint Laboratory for Light Alloys(Ministry of Education),College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [3]Shenyang National Laboratory for Materials Science,Chongqing University,Chongqing 400044,China [4]State Key Laboratory for Advanced Metals and Materials,University of Science and Technology,Beijing 100083,China

出　　处：《Journal of Materials Science & Technology》2023年第15期240-251,共12页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.51871033);the Opening Project of the State Key Laboratory for Advanced Metals and Materials(Nos.2020-ZD02 and 2022-Z03).

摘　　要：Al-Zn-Mg-Cu alloys with different major strengthening precipitates are subjected to a novel combinatorial pre-treatment,including natural ageing and pre-stretching.The evolution of hardness and microstructure during the combinatorial pre-treatment and subsequent artificial ageing has been investigated.The results reveal that the growth rate of hardness in alloy B(Zn/Mg=10.0)is much higher than that of alloy A(Zn/Mg=1.5)due to the fast precipitation kinetics ofηphase compared with T phase.Both GP I zones and dislocations introduced by the combinatorial pre-treatment can act as heterogeneous nucleation sites for precipitation,resulting in more precipitates and higher hardness than pre-stretched alloys A and B.Dislocations distribute uniformly in combinatorial pre-treated alloys owing to the existence of GP I zones and dislocations,which promote the precipitation and refine the precipitate size.Moreover,these alloys with distinct pre-stretching(2%–10%)show similar precipitation behavior and peak hardness,and it indicates that the dislocation-induced precipitation will not be affected by the density of dislocations when plenty of GP I zones pre-exist.

关 键 词：Combinatorial pre-treatment Zn/Mg ratio Ageing behavior Microstructure evolution 

分 类 号：TG146.21[一般工业技术—材料科学与工程]