Dissimilar Joining Of Aluminium Alloy to Copper Using Tungsten Inert Gas Welding Process

Abstract

Aluminium-copper dissimilar joints are applicable to electrical industry. 2 mm thick aluminium alloys (A1100) sheet is joined to 1 mm thick copper (Cu-DHP) sheet using tungsten inert gas welding (TIG) process. The effect of process parameters like heat input, torch orientation, arc weaving on mechanical properties of the joint are studied. In this combination the molten pool generated by melting of aluminium edge will wet the coppersurface to form a leak proof joint. Minimizing the temperature difference aids in improved wetting. Therefore the effect of preheating and tilting on bead formation and joint properties is also investigated. Smooth bead formation is observed with preheating the copper plate. Tilting the joining assembly also showed a positive effect on bead formation. The microstructures of various regions are studied using optical and scanning electron microscope (SEM). Mechanical tests were also conducted using universal testing machine. The failure analysis is carried out using scanning electron microscope.

Keywords:Aluminium-Copper joining, Lap joint, Intermetallics, Brazing, TIG welding.