热处理对压铸Mg-Zn-Al-Mn合金组织及性能的影响  

Effect of Heat Treatment on Microstructure and Properties of Die Casting Mg-Zn-Al-Mn Alloy

作　　者：孙金钊 夏鹏 李润霞 张留艳[1] SUN Jin-zhao;XIA Peng;LI Run-xia;ZHANG Liu-yan(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510000,Guangdong,China;School of Materials Science and Engineering,Dongguan University of Technology,Dongguan 523000,Guangdong,China)

机构地区：[1]广东工业大学材料与能源学院,广东广州510000 [2]东莞理工学院材料科学与工程学院,广东东莞523000

出　　处：《铸造》2024年第5期596-602,共7页Foundry

摘　　要：采用压铸成形工艺制备Mg-Zn-Al-Mn合金,研究不同热处理工艺对压铸Mg-Zn-Al-Mn合金力学性能和显微组织的影响。结果表明,压铸态合金采用直接时效处理时,在190℃下直接时效5 h,合金强度达到峰值,其抗拉强度、屈服强度和伸长率分别为236 MPa,149 MPa和7.3%。经过固溶处理后,过饱和固溶度提升,大部分第二相颗粒在固溶过程中溶解进镁基体中,即有更大的第二相脱溶析出驱动力。335℃×4 h+190℃×5 h时合金力学性能达到最佳,其抗拉强度、屈服强度和伸长率分别为243 MPa,167 MPa和5.1%。浸泡试验表明,经过T6处理后的合金具有最好的耐浸泡腐蚀性能,电化学试验结果显示,T6处理合金具有最小的腐蚀电流密度和最大的高频阻抗弧半径,表明其具有最优的耐腐蚀性能。Mg-Zn-Al-Mn alloy was prepared by die casting,and the effect of different heat treatment on mechanical properties and microstructure of Mg-Zn-Al-Mn alloy was studied.The results show that the tensile strength,yield strength and elongation of the die-cast alloy are 236 MPa,149 MPa and 7.3%,respectively.After solid solution treatment,the supersaturated solid solubility increases,and most of the second phase particles dissolve into the magnesium matrix during the solid solution process.The mechanical properties of 335℃×4 h+190℃×5 h alloy were the best,the tensile strength,yield strength and elongation were 243 MPa,167 MPa and 5.1%,respectively.The immersion test shows that the alloy treated with T6 has the best immersion corrosion resistance.The electrochemical test results show that the alloy treated with T6 has the minimum corrosion current density and the maximum high frequency impedance arc radius,the resultswhich shown that it has the best corrosion resistance.

关 键 词：压铸Mg-Zn-Al-Mn合金 热处理 力学性能 显微组织 腐蚀 

分 类 号：TG166.7[金属学及工艺—热处理]