Hardening effect and precipitation evolution of an isothermal aged Mg-Sm based alloy  

作　　者：Kai Guan Chuang Li Zhizheng Yang Yongsen Yu Qiang Yang Wenwen Zhang Zhiping Guan Cheng Wang Min Zha Huiyuan Wang 

机构地区：[1]Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering,Jilin University,Changchun 130022,China [2]State Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China [3]Department of Energy and Hydrocarbon Chemistry,Graduate School of Engineering,Kyoto University,Nishikyo-ku,Kyoto 615-8510,Japan

出　　处：《Journal of Magnesium and Alloys》2023年第12期4619-4627,共9页镁合金学报（英文）

基　　金：supported by the National Natural Science Foundation of China (Nos.52201120 and 52004100);the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization (RERU2022013);the Fundamental Research Funds for the Central Universities,JLU。

摘　　要：The age-hardening behavior and precipitation evolution of an isothermal aged Mg-5Sm-0.6Zn-0.5Zr(wt.%) alloy have been systematically investigated by means of transmission electron microscopy(TEM) and atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM). The Vickers hardness of the present alloy increases first and then decreases with ageing time. The sample aged at 200 ℃ for 10 h exhibits a peak-hardness of 90.5 HV. In addition to the dominant β_(0)’ precipitate(orthorhombic,a = 0.642 nm, b = 3.336 nm and c = 0.521 nm) formed on {11-20}α planes, a certain number of γ’’ precipitate(hexagonal, a = 0.556 nm and c = 0.431 nm) formed on basal planes are also observed in the peak-aged alloy. Significantly, the basal γ’’ precipitate is more thermostable than prismatic β_(0)’ precipitate in the present alloy. β_(0)’ precipitates gradually coarsened and were even likely to transform into β_(1) phase(face centered cubic, a = 0.73 nm) with the increase of ageing time, which accordingly led to a gradual decrease in number density of precipitates and finally resulted in the decreased hardness and mechanical property in the over-aged alloys.

关 键 词：Magnesium alloys Ageing treatment Microstructure characterization Age-hardening effect PRECIPITATES 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG156.92[金属学及工艺—金属材料]