研究了退火处理对热挤压Mg-5 mass%Zn-1 mass%Y合金组织及性能的影响。结果表明,425℃/15 min为该合金的最佳退火工艺,完全再结晶同时避免晶粒长大,所获得晶粒尺寸仅为10μm。该条件下退火合金的抗拉强度为284.8 MPa,断后伸长率高达31.2%,较高的强度与细小再结晶晶粒及弥散分布的第二相有关;较高伸长率主要源于拉伸过程中{1012}拉伸孪生、{1011}压缩孪生以及({1012}-{1011})拉压二次孪生引起的协调变形。 The effect of annealing treatment on microstructure and properties of hot-extruded Mg-5 mass% Zn-1 mass% Y alloy was studied. The results show that 425 ℃ / 15 min is the best annealing process for the alloy. The complete recrystallization and grain growth are avoided, and the grain size is only 10μm. Under these conditions, the tensile strength of the annealed alloy is 284.8 MPa and the elongation at break is as high as 31.2%. The higher strength is related to the fine recrystallized grains and the second phase of the dispersed distribution. The higher elongation mainly comes from the stretching In the process {1012} stretching twins, {1011} twins and ({1012} - {1011}) stretching and twisting twin coordination.