Y含量对Mg-4Sm-0.6Zn-0.5Zr合金组织及性能的影响  

Effects of Y Content on Microstructure and Mechanical Properties of Mg-4Sm-0.6Zn-0.5Zr Alloy

作　　者：毛红奎[1] 白霄宇 田一清 尹智 王宇 徐宏[1] 孙鹏程[2] 戈迎春[2] Mao Hongkui;Bai Xiaoyu;Tian Yiqing;Yin Zhi;Wang Yu;Xu Hong;Sun Pengcheng;Ge Yingchun(School of Materials Science and Engineering,North University of China;Xi’an Institute of Applied Optics)

机构地区：[1]中北大学材料科学与工程学院,太原030051 [2]西安应用光学研究所

出　　处：《特种铸造及有色合金》2022年第2期194-199,共6页Special Casting & Nonferrous Alloys

基　　金：山西省重点研发计划国际科技合作资助项目(201903D421080);山西省高等学校科技创新项目(2020L0319)。

摘　　要：研究了Y元素对Mg-4Sm-0.6Zn-0.5Zr合金组织及力学性能的影响。结果发现,Mg-4Sm-0.6Zn-0.5Zr合金主要由α-Mg基体、Mg_(24)Y_(5)相、(Mg,Zn);(Y,Sm)相、LPSO结构的Mg_(24)YZn相组成。随着Y含量增加,晶粒逐渐细化,晶界共晶相数量增多,在晶界位置存在共晶次生LPSO相Mg_(24)YZn。LPSO相与α-Mg基体共格,提高了镁合金的强度和硬度。随着Y含量增加,Mg-4Sm-0.6Zn-0.5Zr合金的力学性能不断提高,Y含量达到6.89%时,铸态Mg-4Sm-7Y-0.6Zn-0.5Zr合金的硬度(HV)、屈服强度、抗拉强度以及伸长率分别为95.6、118 MPa、193 MPa、10.5%。Mg-4Sm-0.6Zn-0.5Zr合金的断口和裂纹深度随着Y含量的增加逐渐变浅,台阶数目减少,由准解理脆性断裂转变为解理脆性断裂。The influences of Y element on the microstructure and mechanical properties of Mg-4 Sm-0.6 Zn-0.5 Zr alloy were investigated.The Mg-4 Sm-xY-0.6 Zn-0.5 Zr alloy is mainly composed ofα-Mg matrix,Mg_(24)Y_(5)phase,(Mg,Zn);(Y,Sm)phase,and Mg_(24)YZn phase with LPSO structure.With the increase of Y content,the grains are gradually refined and the amount of eutectic phases at the grain boundary is increased.There exists a eutectic secondary LPSO phase Mg_(24)YZn at the grain boundary.The LPSO phase Mg_(24)YZn is coherent with theα-Mg matrix,which improves the strength and hardness of the magnesium alloy.With the increase of Y content,the mechanical properties of Mg-4 Sm-0.6 Zn-0.5 Zr alloy is improved continously.With the Y content of 6.89%,the hardness,yield strength,tensile strength and elongation of the as-cast Mg-4 Sm-7 Y-0.6 Zn-0.5 Zr alloy reach up to 95.6 HV,118 MPa,193 MPa,10.5%,respectively.The structure of LPSO has an effect on the fracture behavior of magnesium alloy.The fracture mechanism of Mg-4 Sm-7 Y-0.6 Zn-0.5 Zr alloy is characterized by cleavage brittle fracture,and the fracture and crack depth gradually become shallower.

关 键 词：Y元素 稀土镁合金 力学性能 显微组织 LPSO相 

分 类 号：TG146.22[一般工业技术—材料科学与工程]