铝铜异种材料线性摩擦焊接头的微观组织与力学性能

Microstructure and Mechanical Properties of Linear Friction Welded Dissimilar Al-Cu Joints

采用不同的顶锻力对AA5083-H112铝合金和T2纯铜进行了线性摩擦焊接,获得了无明显缺陷的焊接头,并通过扫描电镜、硬度、力学性能试验等方法研究了线性摩擦焊铝铜接头的微观组织和力学性能。结果表明,随着顶锻力的减小,摩擦效应增加,更多的铜颗粒渗入铝基体中;而随着顶锻力的增加,拉伸力学性能明显下降,这是由于较大的顶锻力会使摩擦过程的热输入量增大,从而在铝铜结合处生成层状的第二相Al_2CuMg,使焊接头的力学性能降低。

AA5083-H112 aluminium alloy and T2 pure copper were welded by LFW （linear friction welding） under different forging pressures and joints with no obvious defects were obtained. The mierostrueture and mechanical properties of the LFW joints were investigated by SEM, hardness and tensile tests. The results show that ＂friction effect＂ increases with the decrease of the forging pressure so that more Cu particles infiltrate into the AI base metal. However, with the increase of the forging pressure, the tensile property declines significantly because higher forging pressure could supply more heat input; as a result layered AI2CuMg phase appears which is harmful to the tensile strength of the welds.