A new high-pressure die casting Mg-Gd-Sm-Al alloy with high strength-ductility synergy  

作　　者：Shuhui Lv Youwei Cheng Bo Deng Tao Xu Xin Qiu Qiang Yang 

机构地区：[1]School of Materials Science and Engineering,Changchun University of Science and Technology,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]Kashui International Holdings Limited,Shenzhen,518111,China

出　　处：《Journal of Rare Earths》2024年第12期2239-2248,I0002,共11页稀土学报（英文版）

基　　金：Project supported by the Scientific and Technological Developing Scheme of Jilin Province(20220101239JC,YDZJ202301ZYTS538);the Chinese Academy of Sciences Youth Innovation Promotion Association(2023234)。

摘　　要：A high-pressure die casting(HPDC)Mg-5Gd-1.5Sm-0.7Al alloy was newly developed and exhibits outstanding strength-ductility synergy,with the yield strength and the tensile elongation to fracture being approximately 200 MPa and 8.5%,respectively.This alloy has two types of a-Mg grains:coarse a_(1)-Mg((46±18)μm)and fine a_(2)-Mg((9.2±2.3)μm)grains,and various Al-GS(GS=Gd and Sm)particles located at grain boundaries while clear solute-atom segregation near grain boundaries with limited or free intermetallic particles.Characterizations using Cs-corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)indicate the crystal structures of Al-GS phases.After aging,denseβ'precipitates and chain-shapedβ''-like structures precipitated near grain boundaries while a high density of ultrafineβ''-(Mg,Al)3Sm precipitates and Al-GS clusters formed in grain center.Relatively fine grains,Al-GS primary particles,solute-atom segregation near grain boundaries,and/or multiple precipitates contribute to the high strength of the studied alloy,while the multi-scale a-Mg grains,variety of intermetallic particles but discontinuous skeleton,and the multi-typed precipitated lead to its satisfactory ductility.

关 键 词：Magnesium alloys Strength-ductility synergy Intermetallic phases Scanning/transmission electron microscopy (STEM)Precipitate Rare earths 

分 类 号：TG146.22[一般工业技术—材料科学与工程]