热处理对Mg-3.4Y-3.6Sm-2.6Zn-0.8Zr合金组织和性能的影响（英文）  

Effect of Heat Treatment on the Microstructure and Mechanical Properties of Mg-3.4Y-3.6Sm-2.6Zn-0.8Zr Alloy

作　　者：刘明华[1] 王文礼[1] 张梦奇 邱玉龙 Liu Minghua;Wang Wenli;Zhang Mengqi;Qiu Yulong(Xi'an University of Architecture and Technology, Xi'an 710055, China)

机构地区：[1]西安建筑科技大学

出　　处：《稀有金属材料与工程》2019年第7期2056-2061,共6页Rare Metal Materials and Engineering

基　　金：Science New Star Foundation of Shaanxi Province(2012KJXX-33);Science and Technology Project of Xi’an City(CXYJZKD003);Science and Technology Project of Yulin City

摘　　要：采用差热分析(DSC)、光学显微镜(OM)、硬度测试、X射线衍射(XRD)、扫描电子显微镜(SEM)、能量色散谱(EDS)及拉伸测试等手段研究了Mg-3.4Y-3.6Sm-2.6Zn-0.8Zr(质量分数,%)合金经过不同热处理方式后的组织演变及力学性能。提出了500℃固溶处理15 h、225℃时效处理40 h的最佳热处理制度。500℃固溶处理15 h后,层状长周期堆积有序(LPSO)结构消失,晶界处的(Mg,Zn)3(Y,Sm)从网状相溶解成颗粒状,长条状Mg12(Y,Sm)Zn相的数量增加。时效处理后,大量弥散β′相析出到α-Mg晶粒中,有利于提高合金的屈服强度。试验合金的屈服强度(YS)、抗拉强度(UTS)和延伸率(EL)分别为170.0 MPa、260.8 MPa和14.1%。铸态合金的断裂方式为沿晶脆性断裂,固溶处理合金的断裂模式是具有一定塑性变形的解理断裂,峰值时效合金的断裂模式以解理断裂为主。The microstructure evolution and mechanical properties of Mg-3.4Y-3.6Sm-2.6Zn-0.8Zr(wt%) alloy after different heat treatments were investigated by differential thermal analysis(DSC), optical microscopy(OM), hardness test, X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), and tensile test, and an optimum heat treatment system of solid-solution treatment at 500 °C for 15 h and aging treatment at 225 °C for 40 h was proposed. The results show that after the solution treatment at 500 °C for 15 h, the layer long period stacking ordered(LPSO) structure disappears, whereas the reticular(Mg,Zn)3(Y,Sm) phases at the grain boundaries dissolve into granular phases, and the number of long strip phase Mg12(Y,Sm)Zn increases at the same time. After the aging treatment, a large number of dispersed β′ phases precipitate in the α-Mg grains, which is beneficial to the yield strength improvement of the alloy. The yield strength(YS), ultimate tensile strength(UTS) and elongation(EL) of the experimental alloy are 170.0 MPa, 260.8 MPa and 14.1%, respectively. The fracture mode of the as-cast alloy is intergranular brittle fracture, while that of the solution-treated alloy is cleavage fracture with a certain plastic deformation. The fracture mode of peak-aged alloy is mainly cleavage fracture.

关 键 词：镁合金 热处理 显微组织 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG156.92[金属学及工艺—金属材料]