中文摘要：

利用纯镁、锡粒、纯锌和AZ31合金制备Mg—Sn—Al-Zn系合金，通过调整Sn、Al和Zn含量来研究Mg-Sn-Al-Zn系合金的组织和性能，以获得设计合金的成分范围。通过光学显微金相观察、XRD分析以及硬度测试，研究了添加量5wt％8wt％Sn、2wt％-3wt％Al、1wt％-2wt％Zn的铸态Mg—Sn—Al-Zn系显微组织与力学性能。实验结果表明：Mg-Sn—Al-Zn系合金主要由α-Mg、Mg2Sn相以及较少量的p-Mgl7A112和，τ—Mg32（AI，Zn）49相组成，β-Mg17Al12和T-Mg32（Al，Zn）49相沿枝晶间断续分布。提高Sn含量，可细化枝晶，Sn是影响合金力学性能的主要因素。Al、Zn含量提高时．可提高合金固溶强化效果，而且Al强化效果优于Zn。

英文摘要：

Mg-Sn-AI-Zn alloys with different compositions were made by using pure Mg, Sn, Zn and AZ3 1 alloys. The microstructure and mechanical properties of as cast Mg-Sn-A1-Zn alloys were studied by compositional adjustments of Sn, A1 and Zn. The microstructure observation was studied by optical microscopy and SEM with EDS which was also used to check the composition of phase. X-ray diffraction （XRD） was used to identify the phase consisting. The hardness was analyzed on BBRVD-1 87.5 hardness tester. The results show that Mg-Sn-A1-Zn alloys are mainly composed ofα-Mg and Mg2Sn phase. There are small part of 13-Mg17Al12 and τ-Mg32（A1, Zn）49 phases dispersed at grain boundaries and in dendritic arms. The isolate β-Mg17Al12 and τ-Mg32（A1, Zn）49 phases are not in network form due to the limited quantities. The mechanical tests indicate that the hardness of the alloy increases with the increase of Sn content. Increasing AI and Zn can also increase the hardness of the alloy, and the increase is more effective compared with A1 alloying.