机械合金化Mg-4Zn-xY合金的显微组织和腐蚀行为  

Microstructure and Corrosion Behavior of Mechanically Alloyed Mg-4Zn-xY Alloy

作　　者：付广艳[1] 刘华成 钱神华 Fu Guangyan;Liu Huacheng;Qian Shenhua(School of Mechanical and Power Engineering,Shenyang University of Chemical Technology)

机构地区：[1]沈阳化工大学机械与动力工程学院,沈阳110142

出　　处：《特种铸造及有色合金》2021年第6期722-725,共4页Special Casting & Nonferrous Alloys

基　　金：辽宁省兴辽英才计划资助项目(XLYC1806004);2020年辽宁省教育厅科学研究资助项目(LJ2020015)。

摘　　要：采用高能球磨和真空热压烧结的方法制备出不同钇(Y)含量的Mg-4Zn-xY合金。利用X射线衍射(XRD)、光学显微镜(OM)、扫描电镜(SEM)观察分析合金和腐蚀产物的组成,对合金进行动电位极化、浸泡腐蚀试验并分析其腐蚀性能及原因。结果表明,在Mg-4Zn合金中添加Y元素,有新的第二相(Mg12YZn、Mg24Y5)产生,动电位极化后Mg-4Zn-xY合金形成有效的Mg(OH)2钝化膜,产生钝化现象。添加Y元素有助于合金组织分布更加均匀及晶粒细化,使得第二相呈网状分布,促进钝化且起到腐蚀阻挡层作用,有效提高了合金的耐蚀性能。其中Mg-4Zn-10Y合金组织相对均匀细小,腐蚀电流密度小,腐蚀速度慢,耐腐蚀性能好。Mg-4 Zn-xY alloys with different yttrium(Y)contents were prepared by high energy ball milling and vacuum hot pressing sintering.X-ray Diffraction(XRD),optical microscope(OM)and scanning electron microscope(SEM)were used to observe and analyze the composition of the alloy and corrosion products.Through potentiodynamic polarization and immersion corrosion experiments,the corrosion properties and corrosion mechanism of the alloy were analyzed.The results indicate that with the addition of Y,the formation of new second phases(Mg12YZn,Mg24Y5)can be observed.After potentiodynamic polarization,passivation occurs in Mg-4 Zn-xY alloy and effective Mg(OH)2 passivation film is generated.The addition of the Y element contributes to uniform distribution of the alloy structure and refinement of the grains,leading to the network distribution of the second phase,promoting passivation and acting as a corrosion barrier layer,and effectively improving the corrosion resistance of the alloy.Mg-4 Zn-10 Y alloy has low corrosion current density,low corrosion rate and good corrosion resistance due to its relatively uniform and fine microstructure.

关 键 词：机械合金化 MG-ZN-Y合金 显微组织 耐蚀性 

分 类 号：TG172.5[金属学及工艺—金属表面处理] TG146.21[金属学及工艺—金属学]