热处理对Mg-8Gd-2Nd-1Sm-0.5Zr合金微观组织及力学性能的影响  

Effect of heat treatment on microstructure and mechanical properties of Mg-8Gd-2Nd-1Sm-0.5Zr alloy

作　　者：代跃飞 李全安[1,2,3] 陈晓亚 陈培军[4] DAI Yue-fei;LI Quan-an;CHEN Xiao-ya;CHEN Pei-jun(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,China;Longmen Laboratory,Luoyang 471000,China;Luoyang Shengya Magnesium Alloy Technology Co Ltd,Luoyang 471921,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳471023 [3]龙门实验室,河南洛阳471000 [4]洛阳晟雅镁合金科技有限公司,河南洛阳471921

出　　处：《材料热处理学报》2025年第2期97-105,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(52371108,52201119);龙门实验室前沿探索课题(LMQYTSKT014)。

摘　　要：采用光学显微镜、扫描电镜、X射线衍射仪和电子拉伸实验机等研究了热处理对Mg-8Gd-2Nd-1Sm-0.5Zr合金微观组织和力学性能的影响,并对其强化机制进行分析。结果表明:铸态合金组织主要由α-Mg基体和偏析在晶界处的半连续网状共晶相组成;固溶处理后,共晶相溶入基体中,合金组织主要由α-Mg基体和Mg_(41)RE_(5)相组成;时效处理后,合金组织主要由α-Mg基体、Mg_(5)RE相和Mg_(41)RE_(5)相组成。固溶时效处理后,合金的屈服强度、抗拉强度和伸长率分别达到248 MPa、295 MPa和6.2%,与铸态合金相比分别提高了55%、38.5%和26.5%,不同热处理状态下合金的断裂方式主要为脆性断裂。分析并计算了不同热处理状态合金中各强化机制的贡献,时效态合金中析出强化对屈服强度拥有较高的贡献比,贡献强度为169.8 MPa,占比68.5%。Effect of heat treatment on microstructure and mechanical properties of Mg-8Gd-2Nd-1Sm-0.5Zr alloy was investigated by means of optical microscope,scanning electron microscopy,X-ray diffraction and universal electronic tensile testing machine,and the strengthening mechanisms were analyzed.The results show that the microstructure of the as-cast alloy is mainly composed of α-Mg matrix and semi-continuous network eutectic phases which segregation at grain boundaries.After solution treatment,the eutectic phases dissolve into the matrix,and the microstructure of the alloy is mainly composed of α-Mg matrix and Mg_(41)RE_(5) phase.After aging treatment,the microstructure of the alloy is mainly composed of α-Mg matrix,Mg_(5RE) phase and Mg_(41)RE_(5) phase.After solution and aging treatments,the yield strength,tensile strength and elongation of the alloy are 248 MPa,295 MPa and 6.2%,respectively,which are increased by 55%,38.5% and 26.5% compared to the as-cast alloy,respectively.The fracture mode of the alloy under different heat treatment conditions is mainly brittle fracture.The contribution of various strengthening mechanisms in the alloy with different heat treatment conditions is analyzed and calculated.Precipitation strengthening in the aged alloy has a high contribution ratio to the yield strength,with the contribution strength of 169.8 MPa,accounting for 68.5%.

关 键 词：Mg-Gd-Nd-Sm-Zr合金 热处理 微观组织 力学性能 强化机制 

分 类 号：TG146.2[一般工业技术—材料科学与工程]