Effects of Sn on microstructure of as-cast and as-extruded Mg-9Li alloys  

Sn元素对铸态及挤压态Mg-9Li合金显微组织的影响(英文)

作　　者：蒋斌[1,2,3] 曾迎[1,2] Ming-xing ZHANG 殷恒梅[1,2] 杨青山[1,2] 潘复生[1,2,3] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400044 [3]重庆科学技术研究院新材料中心,重庆401123 [4]昆士兰大学机械与采矿学院

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第4期904-908,共5页中国有色金属学报（英文版）

基　　金：Projects(51171212,50725413) supported by the National Natural Science Foundation of China;Project(2009AA03Z507) supported by the National High-tech Research Program of China;Projects(2010CSTC-BJLKR,CSTC2010AA4048) supported by Chongqing Science and Technology Commission,China;Project(CDJXS10132203) supported by the Fundamental Research Funds for the Central Universities,China

摘　　要：The effects of Sn addition on the microstructure of as-cast and as-extruded Mg-9Li alloys were investigated. The results show that α-Mg, β-Li, Li2MgSn, and Mg2Sn are primary phases in the microstructures of the as-cast and as-extruded Mg-9Li-xSn （x=0, 5; in mass fraction, %） alloys. Li2MgSn phase evolves from continuously net-like structure in the as-cast state to fine granular in the as-extruded state. After the extrusion, Mg-9Li-5Sn alloy has finer microstructures. Li2MgSn or Mg2Sn compound can act as the heterogeneous nucleation sites for dynamic recrystallization during the extrusion due to the crystallography matching relationship Extrusion deformation leads to dynamic recrystallization, which results in the grain refinement and uniform distribution. The as-extruded Mg-9Li-5Sn alloy possesses the lowest grain size of 45.9 μm.研究添加Sn对铸态及挤压态Mg-9Li合金显微组织的影响。结果表明:Mg-9Li-xSn(x=0,5;质量分数,%)合金的铸态和挤压态的组织为α-Mg,β-Li,Li_2MgSn和Mg_2Sn;铸态时Li_2MgSn为连续的网状结构,挤压后变成均匀分布的颗粒状;由晶体学匹配关系可知,Li_2MgSn和Mg_2Sn在挤压时可以作为动态再结晶的异质形核点;挤压变形引起的动态再结晶使得晶粒细化且分布均匀。挤压态的Mg-9Li-5Sn合金具有尺寸为45.9μm的最细晶粒。

关 键 词：Mg-9Li alloys SN MICROSTRUCTURE heterogeneous nucleation 

分 类 号：TG146.22[一般工业技术—材料科学与工程]