AZ61A镁合金等离子焊接头组织与性能

通过拉伸、硬度、弯曲试验和金相组织分析,研究AZ61A镁合金等离子焊接头的拉伸性能、硬度、弯曲性能和金相显微组织。结果表明,拉伸试件的断裂处均位于焊缝区,抗拉强度值分别为220MPa和223MPa,且Rm(W)/Rm(pm)0.7,满足试验要求;所有弯曲试件均未出现断裂,弯曲性能良好;等离子焊所获得的接头热影响区窄且晶粒粗大,焊缝区晶粒细小,组织由α相及其上弥散分布着的灰色点状物Mg17Al12组成;焊缝区整体硬度高于热影响区和母材,热影响区基本未发生软化。

Microstructure and properties of plasma welded joints of AZ61A magnesium alloy

The plasma welded joints of AZ61A magnesium alloy are studied by tensile,hardness and bending tests and metallographic structure analysis respectively.The results show that all the fractures of the tensile specimens are in the weld zone,the tensile strength values are 220 MPa and 223 MPa respectively,and Rm(W)/Rm(pm)＞ 0.7,which meets the test requirements;No fracture is found in any bending specimens,and the bending property is good;The heat affected zone of the joints obtained by plasma welding is narrow,and its grains are coarse,while the grains of the weld zone are fine,the microstructure is constituted by α phase and diffuse gray Mg17Al12 distributed on α phase;The overall hardness of the weld zone is higher than that of the heat affected zone and base metal,and the heat affected zone does not soften basically.