中文摘要：

采用组织分析和拉伸试验，研究了Mg-5Y-3Sm-O．8Ca-（0．1～0．8）sb（％，质量分数）合金的显微组织和抗拉强度。结果表明，铸态合金的显微组织由d·Mg基体和Mg24Y5，Mg4lsm5，Mg2ca，M勖sb2相组成。随着sb含量的增加，时效态合金的室温（20℃）和高温（200，250，300，350℃）抗拉强度均先升高后降低，且在sb含量为0．5％时取得最大值。随着温度的升高，Mg-SY．3Sm-O．8Ca-O．5Sb合金的抗拉强度缓慢降低，其抗拉强度稳定性可归因于强化相Mg24Y5显微硬度的稳定性。

英文摘要：

The microstructure and tensile strength of Mg-SY-3Sm-0.8Ca-（0.1 -0.8 ）Sb alloy was investigated bymicrostructure analysis and tensile tests. The results showed that the microstructure of as-cast alloys consists of ct-Mg matrix and Mg24Ys, Mg41Sms, Mg2Ca and Mg3Sb2. With the increase of Sb addition, the room temperature（20 ℃ ） and high temperature （200, 250, 300, 350 （2 ）decreases, and reaches the peak value at 0.5% Sb. With5Y-3Sm-O. 8Ca-O. 5Sb alloy decreases slowly. Its strengthstrengthening phase Mg24Y5tensile strength of aged alloys increases at first and thenthe increase of temperature, the tensile strength of Mg-stability is attributed to the microhardness stability ofstrengthening phase Mg24Y5.