Er对Mg-5Si合金变质效果和性能的影响  

Effect of Er Modification on Microstructure and Mechanical Properties of Hypereutectic Mg-5Si Alloy

作　　者：刘辉[1,2] 尧军平[1] 柏世梅 张磊[1] 

机构地区：[1]南昌航空大学航空制造工程学院 [2]兰石石油装备工程有限公司

出　　处：《特种铸造及有色合金》2016年第9期1002-1005,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51164027);江西省教育厅重点科技项目(GJJ14502);江西省科技厅国合项目(20151BDH80054)

摘　　要：研究了不同Er含量对Mg-5Si合金中初生Mg_2Si相的变质效果的影响,测试了合金的力学性能,并讨论其变质机理。结果表明,加入适量Er能有效变质初生Mg_2Si相。当加入2.0%的Mg-30Er时,变质效果最佳,此时,初生Mg_2Si相的尺寸在15μm以下,其形态从粗大的树枝状转变为多面体颗粒状,并且分布均匀,此时,合金的抗拉强度和伸长率分别为135 MPa和3.8%。The modification effects of rare earth Er content on primary Mg2Si in hypereutectic Mg-5Si alloy were investigated,and mechanical properties of the alloy containing different Er were tested.In addition,the modification mechanism of Er was described.The results reveal that the primary Mg2Si phase can be modified and refined effectively with adding 2.0% Mg-30 Er,where the average size of primary Mg2Si phase can be decreased from more than 150μm to less than 15μm,and the morphology of primary Mg2Si phase is transformed from the coarse dendrite into fine polyhedron particle with uniform distribution.The tensile strength and elongation of the alloy with 2.0% Mg-30 Er reach 135 MPa and 3.8%,respectively.However,with the Mg-30 Er content more than 3.0%,the primary Mg2Si phase in hypereutectic Mg-5Si alloy becomes coarse again,which is attributed to the enrichment of Er on the growth facets of the primary Mg2Si crystals to depress preferred growth manner of the primary Mg2Si crystals.

关 键 词：ER Mg-5Si合金 初生Mg2Si 变质处理 

分 类 号：TG292[金属学及工艺—铸造]