旋转摩擦焊铝-铜接头的显微组织与力学性能

Microstructure and Mechanical Properties of Al-Cu Joint Made by Rotary Friction Welding

利用旋转摩擦焊工艺实现了1070纯铝与T2纯铜的连接。采用光学显微镜、扫描电子显微镜和电子探针显微分析仪对接头组织和铝-铜界面进行观察分析,并对相同工艺旋转摩擦焊的两块铝-铜接头进行锻压和弯曲试验。结果显示:1号和2号试样在弯曲过程中分别断裂于铝-铜界面和铝侧母材。两种试样的铝-铜界面均未观察到明显的金属间化合物。1号和2号试样铝-铜界面处分别存在宽约1.8和2.7μm的元素过渡区。较宽的元素过渡区可提高铝-铜界面结合强度,较窄的元素过渡区是1号试样在弯曲过程中界面断裂的主要原因。因此,应严格控制旋转摩擦焊的工艺稳定性,以提高焊接接头的弯曲性能。

Connection between 1070 pure aluminum and T2 pure copper was realized by the rotary friction welding technique,the microstructure of the joint and the aluminum-copper interface were observed and analyzed using optical microscope,scanning electron microscope,and electron probe microanalysis,and the forging and bending tests for two welded Al-Cu joints made by the same friction welding processes were carried out.The results showed that the specimens No.1 and No.2 fractured at the Al-Cu interface and Al base metal of aluminum side during bending,respectively.No obvious intermetallic compounds(IMCs)were observed at the Al-Cu interface in both specimens.The width of the element transition zone(ETZ)at the interface for specimen No.1 was about 1.8μm and 2.7μm for specimen No.2.The wider ETZ could improve the bonding strength of the Al-Cu interface,and the thinner ETZ was the main reason for the interface failure of specimen No.1 during bending.Therefore,the process stability of rotary friction welding should be strictly controlled to improve the bending performance of the welded joint.