Microstructure and mechanical properties of large-scale Mg-Gd-Y-Zn-Mn alloys prepared through semi-continuous casting  

作　　者：Kui Wang Jingfeng Wang Xiaoxu Dou Yuanding Huang Norbert Hort Sarkis Gavras Shijie Liu Yanwu Cai Jinxing Wang Fusheng Pan 

机构地区：[1]National Engineering Research Center for Magnesium Alloys,College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [2]MagIC-Magnesium Innovation Center,Helmholtz-Zentrum Geesthacht,Max-Planck-Straβe 1,D-21502 Geesthacht,Germany

出　　处：《Journal of Materials Science & Technology》2020年第17期72-82,共11页材料科学技术（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2016YFB0301100);the Natural Science Foundation Commission of China(Nos.51571044 and 51874062);the Chongqing foundation and advanced research project(No.cstc2019jcyjzdxmX0010);the Fundamental Research Funds for the Central Universities(Nos.2018CDGFCL0005 and 2019CDXYCL0031);the financial support from the China Scholarship Council(No.201906050113)。

摘　　要：Large-scale Mg-8Gd-4Y-1Zn-Mn(wt.%)alloy ingot with a diameter of 315 mm and a length of 2410 mm was prepared through semi-continuous casting.Chemical composition,microstructure and mechanical properties at different locations of the samples with as-cast,T4 and T6 heat-treated states,respectively,were investigated.No obvious macro segregation has been detected in the high-quality alloy ingot.The main eutectic structures at all different locations are composed ofα-Mg,Mg3RE-type,Mg5RE-type and LPSO phases.At the edge of ingot,the unusual casting twins including 10-12 extension twins and 10-11 compression twins were observed due to the intensive internal stress.In T4 heat-treated alloy,the micro segregation was eliminated.The remained phases wereα-Mg and LPSO phase.Combined with the remarkable age-hardening response,T6 samples exhibits improved mechanical properties at ambient temperature,which derives from the dense prismaticβ'precipitates and profuse basalγ'precipitates.

关 键 词：Mg-Gd-Y-Zn-Mn alloy Semi-continuous casting Thermal treatment MICROSTRUCTURE Mechanical properties 

分 类 号：TG146.22[一般工业技术—材料科学与工程]