挤压Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr合金的显微组织与力学性能

摘要

The microstructure,age hardening behavior and mechanical properties of an Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr alloy prepared by casting and hot extrusion techniques were investigated.The solution-treated (T4 temper) alloys were extruded at 400,450 and 500 ℃ with an extrusion ratio of 10:1,respectively.Optimized mechanical properties were obtained by extrusion at 400 ℃ followed by T5 treatment under the combined effects of grain refinement and precipitation strengthening.The alloy exhibits a grain size of about 5.0 μrn,initial and peak microhardness of HV 109 and HV 129,respectively.The tensile yield strength,ultimate tensile strength and elongation at room temperature are 391 MPa,430 MPa and 5.2％,respectively.%研究铸态和挤压态Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr合金的显微组织、时效强化和力学性能.铸锭在T4处理后分别于400、450和500℃进行挤压,挤压比为10:1.在细晶强化和析出强化的共同作用下,于400℃挤压的样品经T5处理后可以得到最优的力学性能,所得的晶粒尺寸约为5.0 μm,其初始和峰值硬度分别为HV109和HV129.室温下的拉伸屈服强度、抗拉强度和伸长率分别达到391 MPa、430 MPa和5.2％.