Surface Characteristics When Solid State Welding of Aluminium Alloys to Magnesium Alloys

Abstract

In the past two decades, there has been an ever-increasing demand for solid-state welding of dissimilar materials. This type of solid-state welding technique is gaining prominence in various disciplines but more importantly in naval, marine, aerospace and military applications. Most of the leading car manufactures today are exploring the possibilities of joining magnesium with aluminium, via solid-state welding process. In the present scenario these techniques are applicable for automotive applications like transmission cases and oil pans. In this work, the different types of solid-state welding techniques that were used for joining of aluminium alloys with magnesium alloys are reviewed from different perceptions. One of the important issues that is faced during joining of these dissimilar materials, is the formation of intermetallic compounds (IMCs) at the welded interface. The work also highlights the influence of various process parameters, structural morphology, intermetallic compound formation and variations in mechanical properties. Some of the important Solid-state welding processes that are elucidated here includes: friction welding, friction stir welding, friction stir spot welding, diffusion welding and third body welding. The above said techniques are carefully analysed for the formation of a satisfactory and quality sound aluminium-magnesium joints. In the overview, it can be summarized that friction-based joining processes have great potential to obtain sound Al–Mg joints. The amount of frictional heat generated at the surface of the contact helps to decide the type and volume fraction of IMCs that are subsequently affecting the mechanical properties of the joints. The joint properties can be enhanced by optimizing the process parameters.