热处理对Mg-Gd-Y-Zr合金组织、性能和腐蚀行为的影响  

Effect of Heat Treatment on Microstructure,Properties and Corrosion Behavior of Mg-Gd-Y-Zr Alloy

作　　者：庞浩 李全安[1,2] 陈晓亚 关海昆[1] Pang Hao;Li Quan’an;Chen Xiaoya;Guan Haikun(School of Materials Science and En-gineering,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)

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

出　　处：《中国稀土学报》2023年第2期331-339,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51571084)资助。

摘　　要：以铸态、固溶态和时效态Mg-11Gd-2Y-0.5Zr合金为研究对象,采用X射线衍射仪(XRD)、光学显微镜(OM)、带能谱的扫描电子显微镜(SEM)以及电子拉伸试验机分析了热处理对Mg-11Gd-2Y-0.5Zr合金的微观组织、微区成分、物相组成以及力学性能的影响,并通过静态失重实验和电化学测试研究了不同热处理状态合金的耐蚀性能。结果表明:铸态Mg-11Gd-2Y-0.5Zr合金组织主要由α-Mg基体、Mg_(5)Gd和少量的Mg_(24)Y_(5)相组成,固溶处理后组织均匀,部分未熔相(富Y相)以颗粒状形式存在,时效态合金析出相尺寸较小且弥散均匀分布。固溶和时效态合金的抗拉强度有不同幅度提升,分别为191.33和265.73 MPa,均表现为准解理断裂特征,在本研究范围内,Mg-11Gd-2Y-0.5Zr合金耐蚀性主要与热处理工艺、析出相的形貌和尺寸有关,不同状态下的合金在腐蚀过程中化学反应类型相似。The effects of heat treatment on the microstructure,microcomposition,phase and mechanical properties of Mg-11Gd-2Y-0.5Zr alloy were studied by an X-ray diffractometer(XRD),an optical microscope(OM),a scanning electron microscope(SEM)with energy spectrum and an electronic tensile testing machine.The corrosion resistance of alloys in different heat treatment states was analyzed by static weight loss and electrochemical test.The results show that the microstructure of as-cast Mg-11Gd-2Y-0.5Zr alloy is mainly composed ofα-Mg matrix,Mg_(5)Gd and a small amount of Mg_(24)Y_(5) phase.After solution treatment,the structure is uniform,some unmelted phase(Y-rich phase)exists in granular form,and the precipitated phase size of the aged alloy is small and dispersed evenly.The tensile strength of solution and aged alloys increases by different ranges,191.33 and 265.73 MPa respectively,which show quasi-cleavage fracture characteristics.In this study,the corrosion resistance of Mg-11Gd-2Y-0.5Zr alloy is mainly related to heat treatment process,morphology and size of precipitates.The chemical reaction types of alloys in different states are similar in the corrosion process.

关 键 词：稀土镁合金 微观组织 力学性能 腐蚀 

分 类 号：TG164.22[金属学及工艺—热处理]