挤压比对Mg-Zn-Y合金微观组织和力学性能的影响

Effect of Extrusion Ratio on Microstructures and Mechanical Properties of Mg-Zn-Y Alloys

研究了在350℃不同挤压比(16、32)下的Mg-6xZn-xY(x=0.5,0.75,1)合金微观组织和室温力学性能。结果表明,当挤压比为32时,合金中第二相体积百分含量较多,平均晶粒尺寸较小。其中,Mg-6Zn-1Y合金在挤压比为16时,α-Mg基体平均晶粒尺寸为14.6μm,抗拉强度及屈服强度分别为264MPa和169MPa;当挤压比为32时,α-Mg基体平均晶粒尺寸为5.9μm,抗拉强度和屈服强度达到337 MPa和237 MPa,分别提高了27.7%和40.3%。另外,所有合金经热挤压后都有良好的塑性,室温拉伸断口均呈韧性断裂特征。

The effect of extrusion ratio（16,32）on microstructures and mechanical properties of as-extruded Mg-6xZn-xY（x=0.5,0.75,1）alloys at 350 ℃ was investigated.The results showed that when the extrusion ratio was 32,the volume fraction of the second phase was higher and the average grain size was smaller.In the Mg-6Zn-1Y alloy,the average grain size ofα-Mg was 14.6μm,and ultimate tensile strength and yield strength were 264 MPa and169 MPa,respectively,when extrusion ratio was 16.In contrast,when extrusion ratio was 32,the average grain size ofα-Mg was 5.9μm,and ultimate tensile strength and yield strength reached 337 MPa and 237 MPa,increased by27.7% and 40.3%,respectively.Moreover,all as-extruded alloys had good ductility,and ductile fracture could be observed at room temperature.