Rapid drop in ductility of the bimodal-structured Mg-15Gd binary alloy during early aging  

作　　者：R.G.Li S.Q.Zhou H.Zhang R.Z.Wu D.Wu J.R.Li B.S.Liu S.S.Li X.Li B.J.Wang 

机构地区：[1]School of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China [2]Key Laboratory of Superlight Materials&Surface Technology,Ministry of Education,Harbin Engineering University,Harbin 150001,China [3]Shenyang Key Laboratory for the Utilization Technology of Magnesium and Calcium Resources,Shenyang University of Chemical Technology,Shenyang 110142,China [4]School of Environmental and Chemical Engineering,Shenyang Ligong University,Shenyang 110159,China [5]CAS Key Laboratory of Nuclear Materials and Safety Assessment,Institute of Metal Research,Chinese Academy of Sciences,62 Wencui Road,Shenyang 110016,China

出　　处：《Journal of Magnesium and Alloys》2024年第9期3772-3779,共8页镁合金学报（英文）

基　　金：supported by National Natural Science Foundation of China(Grant Nos.52171121,51971151,52201131,52201132,52171055 and 52071220);Liao Ning Xingliao Program(XLYC1907083);Natural Science Foundation of Liaoning Province of China(2022-NLTS-18-01);the Open Foundation of Key Laboratory of Superlight Materials&Surface Technology of Ministry of Education(HEU10202205).

摘　　要：A bimodal-structured Mg^(-1)5Gd binary alloy with 45%volume fraction of elongated grains and 55%of dynamically recrystallized(DRXed)grains is fabricated by the extrusion process.The precipitating behavior correlating with the evolution of mechanical properties is systematically characterized during the subsequent aging treatment at 200°C.The extruded alloy presents an outstanding strength with tensile yield strength of 466 MPa and ultimate tensile strength of 500 MPa at peak aging condition,while the elongation drops from 9.2%in extrusion state to 3.1%.It is found there obviously exist a rapidly decreasing range of ductility at the early stage of aging.Just during this time,the nano precipitates form preferentially at lamellar dislocation boundaries(LDBs)within the elongated grains,but there is no dense and uniform precipitation in the matrix.The results suggest that the low elongation in the aged Mg^(-1)5Gd alloy is mainly attributed to the nano precipitates prior formed at the LDBs with a high density in the elongated grains.The related mechanism has been clarified.

关 键 词：Mg-Gd alloy Bimodal structure SEGREGATION PRECIPITATE DISLOCATION Boundary 

分 类 号：TG146.22[一般工业技术—材料科学与工程]