Cu和Si质量分数对铸态Zn-14Al合金组织与性能的影响  

Effect of Cu and Si mass fraction on microstructure and properties of as-cast Zn-14Al alloy

作　　者：陈明明 刘昕怡[1] 祝一帆 艾宇浩 林高用[1,2] CHEN Mingming;LIU Xinyi;ZHU Yifan;AI Yuhao;LIN Gaoyong(School of Materials Science and Engineering,Central South University,Changsha 410083,China;The Key Laboratory of Nonferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2022年第6期2017-2027,共11页Journal of Central South University:Science and Technology

基　　金：湖南省自然科学基金资助项目(2020JJ4715);中南大学中央高校基本科研业务费专项资金资助(2021zzts0576)。

摘　　要：采用XRD、SEM、流动性能测试和硬度测试等方法,研究Cu和Si质量分数对铸态Zn-14Al合金组织与性能的影响。研究结果表明:在铸态Zn-14Al合金中,Cu质量分数为4%~7%时,Cu相主要为ɛ(CuZn_(4)),其弥散分布在α-Al树枝晶间;而Cu质量分数为10%~13%时,存在2种含Cu相,分别为ɛ相和呈五角星形的θ(CuAl_(2))相;随着Cu质量分数提高,合金中的共晶组织增多,合金的流动性能提高;含Cu相维氏硬度比基体相(α,η)维氏硬度高约204,Cu质量分数从0提高至13%时,合金中的硬质含Cu相增多,第二相强化效果显著,抗拉强度和硬度分别提高了17.7%和48.7%。合金中的Si相主要以初晶硅的形式存在,随着Si质量分数的提高,Si相聚集成团生长,合金的硬度略微提高,但流动性能和抗拉强度下降。Zn-14Al-10Cu合金表现出最优的综合力学性能,即布氏硬度为140.8,抗拉强度为398.33 MPa,断后伸长率为4.1%,且该合金兼具良好的流动性能,可作为汽车零件试制模具用锌合金材料。The effects of Cu and Si mass fractions on the microstructure and properties of as-cast Zn-14Al alloys were studied by XRD,SEM,flow property test and hardness test.The results show that in the as-cast Zn-14Al alloy,when the mass fraction of Cu is 4%−7%,the Cu-containing phase is mainlyɛ(CuZn_(4)),which is dispersed among theα-Al dendrites.When the mass fraction is 10%−13%,there are two Cu-containing phases in the alloy,namelyɛphase and the pentagram-shapedθ(CuAl2)phase.With the increase of Cu mass fraction,the eutectic structure in the alloy increases and the fluidity of the alloy increases.The Vickers hardness of Cu-containing phase is about 204 higher than that of the matrix phase(α,η).With the increase of Cu mass fraction from 0 to 13%,the hard Cu-containing phase in the alloy increases.The second phase strengthening effect is remarkable and the tensile strength and hardness increase by 17.7%and 48.7%,respectively.The Si phase in the alloy mainly exists in the form of primary silicon.With the increase of the Si mass fraction,Si phase aggregates and grows into agglomerates.The hardness of the alloy increases slightly,but the flow properties and tensile strength decrease.The Zn-14Al-10Cu alloy shows the best comprehensive mechanical properties.Brinell hardness is 140.8,the tensile strength is 398.33 MPa and the elongation after fracture is 4.1%.Moreover,the alloy has good flow properties,which can be used as zinc alloy material for the trial production of auto parts.

关 键 词：ZN-AL合金 高硬度 显微组织 流动性能 

分 类 号：TG146.13[一般工业技术—材料科学与工程]