Investigations on surface properties and surface morphology in dissimilar joining of WE43 and AA-7075 alloy

Abstract

Joining Mg-Al hybrid structures through fusion welding often yields uneven weld surfaces with an excessive density of intermetallic compounds (IMCs). To mitigate this, solid-state welding methods were employed. In this investigation, Friction Stir Welding (FSW) was used to join WE43 and AA-7075 alloys. Optical microscopy (OM) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) were used to evaluate the microstructural properties of the welded surfaces. Surface characteristics, including wear, microhardness, and corrosion, were assessed through wear testers, micro-hardness testers, and potentio-dynamic polarization tests. The results indicated a reduction in IMC content. These findings enhance our understanding of how ambient air and DM-water, as variable process parameters, influence the surface properties, strength, and morphology of Mg-Al dissimilar joints.