Mg-6wt%Zn-1wt%Mn镁合金均匀化处理研究
Study on Homogenization Treatment for Mg-6wt%Zn-1wt%Mn Magnesium Alloy
张丁非1,2, 方 霖1,2, 段红玲1,2, 戴庆伟1,2
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作者单位:1. 重庆大学 材料科学与工程学院, 重庆 400045; 2. 重庆大学 国家镁合金材料工程技术研究中心, 重庆 400044)
中文关键字:ZM61镁合金; 均匀化; 显微组织; 显微硬度
英文关键字:ZM61 magnesium alloy; homogenization; microstructure; microhardness
中文摘要:利用差热分析仪(DSC)、金相显微镜(OM)、扫描电镜(SEM)、能谱分析仪(EDS)和显微硬度测试仪,对不同的均匀化热处理工艺下铸态ZM61镁合金组织转变和成分均匀化效果进行了表征。 并采用求显微硬度方差大小的方法对均匀化过程中的两个重要参数——温度和时间进行了深入探讨。结果表明:铸态ZM61镁合金显微组织中存在严重的枝晶偏析,枝晶间有粗大的呈网状分布的Mg-Zn相,枝晶内部和枝晶臂间也存在大块状化合物;温度是均匀化过程中的主导因素,过度延长保温时间对均匀化作用不大;ZM61镁合金较优的均匀化工艺:330 ℃ × 16 h + 420 ℃ × 2 h。
英文摘要:The effects of homogenization treatment on the microstructure transformation and composition homogenization of Mg-6Zn-Mn alloy as-cast were investigated by DSC, OM, SEM, EDS and microhardness tester. The parameters of heat process(temperature and time) were studied by the variance of microhardness distribution. The results show that severe dendritic segregation existes in as-cast structures, Mg-Zn phase distributes in interdendritic as the network structure, and there are also some large compounds in the dendrite and dendritic arm; the annealing temperature plays a main role in homogenizing of ZM61 alloy, excessively holding time has little effect on homogenization. The optimized annealing process of ZM61 magnesium alloy is homogenized at 330 ℃ for 16 h then at 420 ℃ for 2 h.