中文摘要：

为明确Zr含量对Mg-5Gd-3Y-xZr合金晶粒尺寸的影响规律,并优化不同Zr含量镁合金固溶处理参数.通过光学显微观察、常温压缩试验,研究了Mg-5Gd-3Y-xZr（x=0%,0.3%,0.6%）合金铸态光学显微组织和力学性能,以及固溶态光学显微组织,统计了合金晶粒尺寸,测定了屈服强度,拟合了霍尔-佩奇公式.实验结果表明：随着Zr含量提高,Mg-5Gd-3YxZr合金晶粒尺寸明显降低,屈服强度与抗压强度提高,且屈服强度与晶粒尺寸关系符合霍尔-佩奇公式,其中佩奇斜率K约为410.Mg-5Gd-3Y,Mg-5Gd-3Y-0.3Zr和Mg-5Gd-3Y-0.6Zr合金最佳固溶处理参数分别为520℃×4h,480℃×6h和450℃×12h。

英文摘要：

The effect of different content of Zr on grain size of Mg-SGd-3Y-xZr alloy was studied and conditions of the solution treatment of magnesium alloy were optimized. The microstructure and compression properties of Mg-5Gd-3Y-xZr alloys （x=0% ,0.3% ,0.6%） in as-casting and after solution treatment were investigated, and the grain sizes were counted. The yield strength and compressive strength were measured by compression test in room temperature. The results show that with the content of Zr increasing, the grain size of Mg-SGd-3Y-xZr alloy decreases, and yield strength and compressive strength increase. The relationship between the yield strength and grain size is in line with Hall-Perch equation. The optimal solution treatment conditions of Mg-SGd-3Y, Mg-SGd-3Y-0.3Zr and Mg-5Gd-3Y-0.6Zr are 520℃ ×4 h,480℃ ×6 h and 450℃×12 h,respectively.