Grain refinement mechanism of Mg-3Sn-1Mn-1La alloy during accumulative hot rolling  

作　　者：Z.Y.Zhao R.G.Guan Y.F.Shen P.K.Bai 

机构地区：[1]School of Materials Science and Engineering,North University of China,Taiyuan 030051,China [2]bEngineering Research Center of Continuous Extrusion,Ministry of Education,Dalian Jiaotong University,Dalian 116028,China [3]Key Laboratory for Anisotropy and Texture of Materials,Northeastern University,Shenyang 110004,China

出　　处：《Journal of Materials Science & Technology》2021年第32期251-261,共11页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China (Grant No.51775521);the China Postdoctoral Science Foundation (2019M661068);the Key Research and Development Project of Shanxi Province (201903D121009);the Natural Science Foundation of Shanxi Province (201801D221154)。

摘　　要：We elucidate the effect of lanthanum(La) on the grain refinement of Mg-3 Sn-1 Mn alloy during accumulative hot rolling. The lath-shaped Mg_(2) Sn phase in the Mg-3 Sn-1 Mn alloy is firstly broken and spheroidized,and then the size increases and coarsens with the increase of rolling reduction, most of Mg_(2) Sn move from grain boundary to grain and are homogeneously distributed within the matrix. However, the plate-shaped Mg Sn La compound in Mg-3 Sn-1 Mn-1 La gradually becomes fine, spheroidized, and homogeneously distributed. The grain sizes of Mg-3 Sn-1 Mn and Mg-3 Sn-1 Mn-1 La alloys become fine through dynamic recrystallization(DRX), though the grain refinement of Mg-3 Sn-1 Mn-1 La alloy is better compared to the Mg-3 Sn-1 Mn alloy. A large number of uniformly distributed spherical Mg Sn La compounds pin the dislocations, thus increasing the dislocation density. Hence, the driving force for DRX increases and promotes the formation of deformation bands and more twins, providing the sites for DRX nucleation and growth.

关 键 词：Mg alloy Grain refinement Dynamic recrystallization Accumulative hot rolling 

分 类 号：TG339[金属学及工艺—金属压力加工]