中文摘要：

降低挤压温度是细化镁合金晶粒和提高强度的有效手段，但对靠析出强化的AZ80镁合金来说，降低挤压温度会造成挤压时的析出，从而影响最终时效的效果。分析了在工业生产用挤压机上380℃和330℃挤压出的AZ80镁合金挤压和时效的组织和性能。结果表明：330℃挤压可获得6μm的均匀等轴晶粒组织，但冷却后的样品中明显存在析出物，后续时效过程较快，但最高强度不如高温挤压样品的最高强度；在380℃下挤压并时效后，其最高抗拉强度可达400MPa，延伸率可达8％。X射线衍射织构测定表明，{0002}//挤压轴的织构对性能的提高也起一定的作用。

英文摘要：

Reducing extrusion temperature is the effect way to refine the grain and enhance mechanical properties of magnesium alloys. However, it may also stimulate the precipitation of second phase during extrusion of AZ80 alloy, and therefore reduce the hardening effect. The microstructures and mechanical properties of these two types of AZ80 magnesium alloys extruded at 380℃ and 330℃, respectively, on a commercial extruding machine were analyzed. The results indicate that the microstructure with grain size of 6μm is obtained at the extrusion temperature of 330 ℃. However, the second phase is precipitated along the grain boundaries during deformation which influence subsequent microstructure evolution and properties. Ultimate tensile strength over 400 MPa with an elongation of 8% is achieved after aging treatment of the 380 ℃-extruded samples. The strong extrusion texture of {0002} is deter- mined and regarded to be responsible mainly for the high properties compared with the grain refinement and precipitation.