中文摘要：

利用相图热力学数据库设计Mg-Al-Zn-Sm系合金的成分和热处理工艺。合金经熔炼铸造后进行T6工艺热处理。通过硬度测试确定合金的峰时效点,并在峰时效点进行室温拉伸实验。结果表明：成分为Mg-6Al-1.3Sm-1Zn（质量分数,%）的样品时效后的抗拉强度（σb）为263 MPa。采用X射线衍射（XRD）和透射电子衍射（TEM）并结合X射线能谱分析方法确定合金基体为Mg-Zn固溶体,析出相为Mg17Al12与Al2Sm。借助金相光学显微技术与扫描电镜（SEM）对合金的微观组织形貌进行分析,并采用热力学计算对显微组织的形成进行解释。示差扫描量热技术（DSC）测试结果表明：合金凝固过程中的相变点与计算模拟的结果吻合。

英文摘要：

The alloy composition and process parameters of Mg-A1-Zn-Sm alloy were designed by using thermodynamic database. T6 heat treatment was carried out, following the melting and casting. According to hardness measurement, peak aging time was found. Tensile experiments were carried out. The results show that the tensile strength （ab） is 263 MPa in the tensile experiment to the alloy sample of the composition Mg-6AI-I.3Sm-IZn （mass fraction, %）. Mg-Zn solid solution matrix, AIESm and MglTAII2 precipitates were determined in alloys by using X-ray diffraction （XRD） and transmission electronic microscopy （TEM） along with X-ray spectrum （EDX）. Combined optical microscopy with scanning electronic microscopy （SEM）, the microstructures of samples in casting and annealing states were observed. The experimental results were discussed based on thermodynamics. Differential scanlaing calorimeter （DSC） was employed to test the phase transformation points in the solidification. The experimental data are consistent with the simulation results by thermodynamic database.