固溶处理后镁铝合金时效峰值硬度时微观结构的电子显微分析  

Electron microscopy study of microstructures at peak-hardness during aging process in a dissolution-treated Mg-Al based alloy

作　　者：陶红玉[1,2] 刘玉[1,2] 聂鑫[1,2] 赵东山[1,2] 周嘉萍[1,2] 王建波[1,2] 桂嘉年[1,2] 

机构地区：[1]武汉大学物理科学与技术学院人工微结构教育部重点实验室,湖北武汉430072 [2]武汉大学电子显微镜中心,湖北武汉430072

出　　处：《电子显微学报》2012年第6期455-460,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.51171130;50771074和50571075);教育部新世纪优秀人才支持计划(No.NCET-07-0640)

摘　　要：用显微维氏硬度计、金相显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究分析了Mg-10.33wt.%Al-1.26wt.%Zn合金固溶后的时效硬化规律。实验结果表明AZ91(Mg-9wt.%Al-1wt.%Zn-0.2wt.%Mn)合金添加少量的Al后固溶强化和时效强化效果均有显著提高。实验的时效硬度曲线表明:固溶处理后的Mg-10.33wt.%Al-1.26wt.%Zn合金在473K时效10 h获得最佳时效强化效果。经过分析,进一步证实Mg-10.33wt.%Al-1.26wt.%Zn合金固溶后时效过程中单位体积内的连续析出相γ-Mg17Al12相颗粒的数目(Nv)越大,样品的显微硬度值越高。Age-hardening behavior of the Mg-10.33wt.%Al-1.26wt.%Zn alloy after solution treatment was observed and analyzed by a micro-Vikers hardness tester,X-ray diffraction（XRD）,optical microscopy（OM）,scanning electron microscopy（SEM）,and transmission electron microscopy（TEM）.The results show that solid solution strengthening and age-hardening of the Mg-10.33wt.%Al-1.26wt.%Zn alloy are both greatly improved,compared with AZ91（Mg-9wt.%Al-1wt.%Zn-0.2wt.%Mn）.The age-hardening curves show that aging at 473K for 10 h,the dissolution-treated Mg-10.33wt.%Al-1.26wt.%Zn alloy will reach its peak-hardness.The present results and analysis confirm that continuous precipitation plays an important role in improving age-hardening effects in Mg-Al based alloys.

关 键 词：镁合金 显微硬度 析出相 

分 类 号：TG156.94[金属学及工艺—热处理]