挤压变形Mg-5Li-2.6Al-1.8Zn合金的显微组织及力学性能

Microstructure and mechanical properties of the as-extruded Mg-5Li-2.6Al-1.8Zn alloy

采用真空感应熔炼炉熔铸了Mg-5Li-2.6Al-1.8Zn合金,对该合金进行了挤压变形,采用OM、SEM、XRD、EDS等检测了挤压态合金的显微组织,室温拉伸试验测试了挤压态合金的力学性能,并观察了断口形貌。结果表明,挤压态Mg-5Li-2.6Al-1.8Zn合金由基体α-Mg和少量的AlLi相组成,晶粒尺寸细小。挤压态Mg-5Li-2.6Al-1.8Zn合金具有较高的力学性能,抗拉强度达到260 MPa,伸长率为20.7%,断口主要由韧窝组成,合金具有较好的韧性。

Mg-5Li-2.6Al-1.8Zn alloy was cast in a vacuum induction melting furnace and extruded thereafter.The microstructure of the as-extruded alloy was detected by OM,SEM XRD,and EDS.The mechanical properties of the as-extruded alloy were tested by tensile testing at room temperature.And the fracture morphology was observed.The results indicate that the as-extruded Mg-5Li-2.6Al-1.8Zn alloy is composed ofα-Mg base and a slight amount of AlLi phase,with fined grain sizes.The as-extruded Mg-5Li-2.6Al-1.8Zn alloy has high mechanical properties,with tensile strength of 260 MPa and elongation of 20.7%.The fracture surface is mainly composed of dimples and the alloy has a good plasticity.