(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究了微量Mn、 Zr对Mg-13％Gd和Mg-9％Gd-4%Y合金铸态和挤压后的微观组织及力学性能的影响。 结果表明： 在铸态， 含Zr合金的晶粒明显小于不含Zr的合金， 而Mn对合金的铸态显微组织影响不大； 将Mg-9％Gd-4%Y-0.6％Mn和Mg-9％Gd-4%Y-0.6％Zr合金挤压后，都可以得到非常细小均匀的等轴晶， 晶粒尺寸约14 μm； 这两个合金在挤压时效态（T5）的力学性能都明显优于WE54合金的， 且Mg-9％Gd-4%Y-0.6％Zr合金比Mg-9％Gd-4%Y-0.6％Mn合金性能更好。
关键字: Mg-Gd-Y-Zr-(Mn)合金； 显微组织； 晶粒细化； 力学性能
properties of Mg-Gd-Y alloys
（ School of Materials Science and Engineering，
Central South University, Changsha 410083, China）
Abstract: The effect of small amount of Mn and Zr on the microstructure and mechanical properties of Mg-13%Gd and Mg-9%Gd-4%Y alloys was studied. The results show that the grains of the Zr-containing alloys are much finer than those of the Zr free alloys in as-cast, and Mn has little effect on the as-cast microstructure. After Mg-9％Gd-4%Y-0.6％Mn alloy and Mg-9％Gd-4%Y-0.6％Zr alloy are extruded, the very fine particle about 14 μm and uniform grains are obtained. The mechanical properties of the two alloys at the extruded-T5 state are all better than those of the WE54 alloy, and the properties of the Mg-9％Gd-4%Y-0.6％Zr alloy are superior to those of the Mg-9％Gd-4%Y-0.6％Mn alloy.
Key words: Mg-Gd-Y-Zr-(Mn) alloy; microstructure; grain refinement; mechanical properties
