热处理对Mg-6Sn-3Zn-x Al合金微观组织和力学性能的影响  

Effect of heat treatment on microstructure and mechanical properties of Mg-6Sn-3Zn-xAl alloys

作　　者：杜佳贝 张扬 卢雅琳 Du Jiabei;Zhang Yang;Lu Yalin(School of Materials Engineering,Jiangsu University of Technology,Changzhou Jiangsu 213001,China)

机构地区：[1]江苏理工学院材料工程学院,江苏常州213001

出　　处：《金属热处理》2024年第11期256-262,共7页Heat Treatment of Metals

基　　金：中国博士后科学基金面上项目(2019M650096);江苏省高等学校基础科学(自然科学)重大项目(21KJA430009);常州市科技支撑计划(社会发展)(CE20235041);江苏省研究生高校创新计划(XSJCX22-02)。

摘　　要：利用XRD、OM、SEM、硬度测试和拉伸试验等方法,研究了热处理对不同Al含量Mg-6Sn-3Zn-xAl(x=0、1、2、3)合金微观组织和力学性能的影响规律。结果表明,铸态Mg-6Sn-3Zn合金由α-Mg等轴枝晶和Mg_(2)Sn相组成,Al元素的加入使得铸态合金的晶粒细化,同时在合金中形成了Mg_(x)(ZnAl)_(1-x)准晶相。经320℃×3 h+430℃×24 h固溶处理后,Mg-6Sn-3Zn-xAl合金中的Mg_(x)(ZnAl)_(1-x)准晶相完全溶解,Mg_(2)Sn相大部分溶解但有少量残留。时效硬化曲线表明,在200℃时效过程中,Mg-6Sn-3Zn-xAl合金均在216 h达到峰时效,峰时效合金中析出大量弥散分布的Mg_(2)Sn相。Al元素的加入带来的一定的强化作用,而固溶和时效处理均在一定程度上提升了合金的力学性能。合金力学性能的改善分别来自于细晶强化、固溶强化和沉淀强化的贡献。Effect of heat treatment on microstructure and mechanical properties of Mg-6Sn-3Zn-xAl(x=0,1,2,3)alloys with different Al contents was studied by using XRD,OM,SEM,hardness test and tensile test.The results indicate that the as-cast Mg-6Sn-3Zn alloy is composed ofα-Mg equiaxed dendrites and Mg_(2)Sn phase.The addition of Al element causes grain refinement of the as-cast alloy,and the Mg_(x)(ZnAl)_(1-x)quasicrystal phase is formed in the alloy.After 320℃×3 h+430℃×24 h solution treatment,the Mg_(x)(ZnAl)_(1-x)quasicrystal phase in the Mg-6Sn-3Zn-xAl alloy is completely dissolved,while the Mg_(2)Sn phase is mostly dissolved but has a small amount of residue.The aging hardening curve shows that during the aging process at 200℃,the Mg-6Sn-3Zn-xAl alloys all reach peak when aged for 216 h,and a large number of dispersed Mg_(2)Sn phases are precipitated in the peak aged alloy.The addition of Al element brings a certain strengthening effect,and both solution treatment and aging treatment improve the mechanical properties of the alloy to a certain extent.The improvement of mechanical properties of the alloy comes from the contribution of refined crystalline strengthening,solution strengthening and precipitation strengthening,respectively.

关 键 词：Mg-6Sn-3Zn-xAl合金 热处理 微观组织 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]