差热-等通道转角挤压工艺对TZK镁合金微观组织与腐蚀性能的影响  

Influence of differential thermal-ECAP on microstructure and corrosion properties of TZK magnesium alloy

作　　者：李亚琴 张敏洁 郭菲菲 周田水 刘德学[1,2] LI Ya-qin;ZHANG Min-jie;GUO Fei-fei;ZHOU Tian-shui;LIU De-xue(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050

出　　处：《塑性工程学报》2024年第8期58-68,共11页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(12162023);甘肃省重点人才项目(甘财行【2023】11);甘肃省创新群体项目(23JRRA757)。

摘　　要：采用光学显微镜、扫描电镜、电化学、X光电子能谱分析等测试技术探究了差热-等通道转角挤压工艺(DT-ECAP)对Mg-5Sn-2Zn-0.5Zr(TZK)镁合金微观组织和腐蚀性能的影响。结果表明,当模具温度为300℃、试样保持室温时(DT-1),TZK镁合金晶粒和第二相显著细化,且第二相呈弥散分布。此外,在DT-1变形条件下,TZK镁合金在Hank′s溶液中呈现均匀腐蚀,腐蚀速率为1.161 mm·a^(-1),腐蚀电位与腐蚀电流密度分别为-1.38 V和5.916×10^(-6)mA·cm^(-2),合金耐蚀性能最优。而当模具温度为300℃、试样温度为200℃(DT-2)以及模具保持室温、试样温度为300℃(DT-3)时,合金中的第二相沿变形方向呈带状分布,且局部区域存在粗大的块状第二相,其在Hank′s溶液中的腐蚀以局部腐蚀为主。The influence of differential thermal-equal channel angular pressing(DT-ECAP)on the microstructure and corrosion properties of Mg-5Sn-2Zn-0.5Zr(TZK)magnesium alloy was explored using optical microscopy(OM),scanning electron microscopy(SEM),electrochemistry,X-ray photoelectron spectroscopy(XPS)and other testing techniques.The results show that when the die temperature is 300℃and the sample is kept at room temperature(DT-1),the grains and the second phase of TZK magnesium alloy are significantly refined,and the second phase is diffusely distributed.In addition,under the DT-1 deformation condition,TZK magnesium alloy shows uniform corrosion in Hank′s solution,with corrosion rate of 1.161 mm·a^(-1),the corrosion potential and corrosion current density are-1.38 V and 5.916×10^(-6)mA·cm^(-2),respectively,and the corrosion resistance of the alloy is the best.When the die temperature is 300℃,the sample temperature is 200℃(DT-2)and the die is kept at room temperature,the sample temperature is 300℃(DT-3),the second phase is distributed in band shape along the deformation direction,and there is the coarse massive second phase in the local area,its corrosion in Hank′s solution is mainly local corrosion.

关 键 词：Mg-5Sn-2Zn-0.5Zr合金 差热-等通道转角挤压变形 微观组织 腐蚀性能 

分 类 号：TG178[金属学及工艺—金属表面处理]