Effect of Sr content on microstructure and mechanical properties of Mg-Li-Al-Mn alloy  

Sr含量对Mg-Li-Al-Mn合金显微组织及力学性能的影响(英文)

作　　者：许天才 彭晓东[1,2] 姜军伟[1] 谢卫东[1,2] 陈元芳[1,3] 魏国兵[1] 

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]重庆理工大学材料科学与工程学院,重庆400050

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第9期2752-2760,共9页中国有色金属学报（英文版）

基　　金：Project(2007CB613702)supported by the National Basic Research Program of China;Project(2008BB4323)supported by the Natural Science Foundation of Chongqing Science and Technology Commission,China;Project(2010DFR50010)supported by the International Scientific and Technological Cooperation Projects,China

摘　　要：The as-cast Mg-8Li-3Al-0.5Mn-xSr（LAM830-xSr, x=0-1.0） alloys were designed and prepared in a vacuum induction furnace under controlled argon atmosphere. The alloys were then processed by hot extrusion, and their microstructural evolution and mechanical properties were analyzed. Results indicate that the LAM830 alloy mainly consists of α-Mg, β-Li, Al2Mn3, and LiMgAl2 phases. Sr addition results in the precipitation of Al-Sr. Moreover, Sr addition results in a fact that the secondary dendrite arm spacing（DAS） of the primary α-Mg phase is obvious refined. Microstructure of the investigated alloys is further refined as a result of the hot extrusion treatment. The content and morphology of the secondary phases have important effects on the mechanical properties of the alloys. The as-extruded LAM830-0.5Sr alloy exhibits an optimal elongation of 22.43% and as-extruded LAM830-0.75 Sr alloy shows an optimal tensile strength of 265.46 MPa.利用真空感应炉在氩气保护下,设计与制备Mg-8Li-3Al-0.5Mn-xSr（x=0-1.0）合金,并将其进行热挤压处理。分别研究合金铸态与挤压态显微组织和拉伸性能。结果表明：LAM830合金主要含有α-Mg,β-Li,Al2Mn3和LiMgAl2相。在加入Sr后合金中出现Al-Sr析出相。Sr对铸态合金α-Mg基体的二次枝晶臂有明显细化效果。经过热挤压处理的合金组织远优于铸态的合金组织。金属间化合物的含量与形态对合金力学性能的影响很大,其中挤压态的LAM830-0.5Sr具有最佳的伸长率（22.43%）,LAM830-0.75Sr合金具有最佳的抗拉强度（265.46 MPa）。

关 键 词：Mg-Li alloy dendrite arm spacing Al4Sr phase mechanical properties 

分 类 号：TG146.22[一般工业技术—材料科学与工程]