中文摘要：

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。

英文摘要：

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.