Pb-Sn对压铸AZ81镁合金组织和力学性能的影响  

Effects of Pb-Sn on Microstructure and Mechanical Properties of Die Casting AZ81 Magnesium Alloy

作　　者：马小黎[1,2] 游国强 郭伟[1] Ma Xiaoli;You Guoqiang;Guo Wei(Chongqing University,Chongqing 400044,China;National Engineering Research Center for Magnesium Alloy Materials,Chongqing 400030,China;Chongqing Daming Automobile Electric Appliance Co.Ltd,Chongqing 401122,China)

机构地区：[1]重庆大学,重庆400044 [2]重庆市大明汽车电器有限公司,重庆401122 [3]国家镁合金材料工程技术研究中心,重庆400030

出　　处：《稀有金属材料与工程》2018年第8期2525-2530,共6页Rare Metal Materials and Engineering

基　　金：重庆大学大型仪器设备开放基金(201512150010);四川省科技计划项目(2013GZ0128)

摘　　要：向AZ81镁合金中分别加入0.5%Pb、0.5%Pb+0.5%Sn、0.5%Pb+1.0%Sn合金元素并压铸成型,研究了各成分合金的微观组织和室温、180℃力学性能。结果表明:AZ81-0.5Pb-1.0Sn中存在多边形Mg2Sn,主要分布在晶界;同时,Pb和Sn元素的加入在一定程度上减少了晶界上Mg17Al12的数量,有助于提高镁合金的耐中高温性能;室温下,压铸AZ81-0.5Pb-(0,0.5,1.0)Sn合金抗拉强度和屈服强度随着Sn含量的增加而提高,压铸AZ81-0.5Pb-1.0Sn的抗拉强度为211 MPa、屈服强度为150.5MPa;180℃下,随着Sn含量的增加,抗拉强度和屈服强度均提高,压铸AZ81-0.5Pb-1.0Sn抗拉强度值为200.5 MPa、屈服强度为145.2 MPa;添加元素Pb+Sn使压铸AZ81的180℃断裂机制由塑性断裂向脆性断裂转变。Effects of adding alloying elements （0.5%Pb, 0.5%Pb＋0.5%Sn, 0.5%Pb＋1.0%Sn） on the microstructure and mechanical properties of die casting AZ81 alloy at room temperature and 180℃ were investigated. Results show that in the alloy of AZ81-0.5Pb-l.0Sn, there is polygon Mg2Sn phase at grain boundary. In the meantime, Pb and Sn suppress the formation of precipitation MglTA112 at grain boundary to a certain extent, which contributes to the medium temperature resistance. At room temperature, the tensile strength and yield strength of the alloys increase with the increase of Sn content. The tensile strength and yield strength of die casting AZ81-0.5Pb-1.0Sn at room temperature are 211 MPa and 150.5 MPa, respectively. At 180℃, the tensile strength and yield strength increase with the increase of Sn content as well. The tensile strength and yield strength of die casting AZ81-0.5Pb-1.0Sn alloy at 180 ℃ are 200.5 MPa and 145.2 MPa, respectively. Pb-Sn makes the fracture mechanism of AZ81 transfer from plasticity to brittleness.

关 键 词：镁合金 压铸 Pb SN 中高温力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]