Characterisation of Cu–Al alloy lap joint using TIG Welding

Abstract

It is difficult to join dissimilar material which has different thermal and mechanical properties using conventional arc welding, which is prone to the formation of intermetallic compounds (IMCs). In the present work pure copper (Cu) and aluminium (Al) alloy (Al-6061) is lap joined by conventional TIG Welding. At optimal operating condition, a successful weld is achieved as observed from mechanical testing. The metallurgical properties of joints are investigated by Back Scattered Electron (BSE) image, spot Energy Dispersive X-ray Spectroscopy (EDS) and line EDS. IMCs layers formed for joints varied from 9 μm to 80 μm thickness obtained at different welding parameters. Two different layers of IMCs are formed at the interface and the failure occurred near the copper side of the joint. The mechanical property is investigated by tensile shear test, and the average maximum load-carrying capacity found 1876 N, which is comparable to other non-conventional welding processes.