Relieving segregation in twin-roll cast Mg-8Al-2Sn-1Zn alloys via controlled rolling  

作　　者：Shao-You Zhang Cheng Wang Hong Ning Tong Wang Cheng-Cheng Zhang Zhi-Zheng Yang Hui-Yuan Wang 

机构地区：[1]State Key Laboratory of Automotive Simulation and Control,Jilin University,PR China [2]Key Laboratory of Automobile Materials of Ministry of Education and School of Materials Science and Engineering,Jilin University,Nanling Campus,No.5988 Renmin Street,Changchun 130025,PR China [3]International Center of Future Science,Jilin University,Changchun 130012,PR China

出　　处：《Journal of Magnesium and Alloys》2021年第1期254-265,共12页镁合金学报（英文）

基　　金：Financial supports from The National Natural Science Foundation of China(Nos.51625402,51790483,51801069 and U19A2084)are greatly acknowledged;Partial financial support came from The Science and Technology Devel-opment Program of Jilin Province(Nos.20190901010JC,20190103003JH,20200401025GX and 20200201002JC);The Changjiang Scholars Program(T2017035).

摘　　要：Twin-roll casting(TRC)of Mg alloys with high Al content has unique advantages and broad development prospects.However,the severe segregation of high-alloyed Mg caused by TRC technology is difficult to solve at present,which restricts its practical application.In this work,the homogenization of coarse segregated phases in a twin-roll cast Mg-8Al-2Sn-1Zn(ATZ821)alloy was successfully achieved by a method combining solid-solution heat treatment and controlled rolling,which is suitable for industrial-scale production.In addition,the evolution of the microstructure was studied in detail.It was found that phases dynamically precipitated and dissolved repeatedly during the hot rolling process,and the evolution of entire second phases can be classified into three stages,i.e.,the net dissolution,balancing and net precipitation stages.During the process,the large-size chain-like eutectic phases evolved into a fine and nearly spherical(∼0.4μm)morphology that was uniformly dispersed in the Mg-matrix due to the thermodynamic coupling and the Ostwald ripening effect.Moreover,a fine grain microstructure(∼4μm)was obtained.The formidable segregation problem of twin-roll cast Mg alloys with high Al content was solved,which is an important finding for the industrial application of high-alloyed twin-roll cast sheets.©2020 Published by Elsevier B.V.on behalf of Chongqing University.

关 键 词：Twin-roll cast Mg alloys Segregated phase Microstructure evolution Industrial production 

分 类 号：TG339[金属学及工艺—金属压力加工] TG156.94