Continuous drive dissimilar friction welding of wrought aluminium AA6063-T6 and austenitic stainless steel AISI304L with different welding methods and welding trials

Abstract

Welding dissimilar metals by fusion welding process is a tough task, as both metals have different thermomechanical properties. In this study, experiments are carried out to join aluminium AA6063-T6 and steel AISI304L dissimilar alloys with different faying surface modifications through a continuous drive friction welding process (CDFW). This study aims to introduce the joining methods and evaluate the performance of their fabricated joints through microstructure and mechanical characterisations. Here, friction time (3, 5, and 7 s) is varied, whereas friction and upset pressures are kept constant. The faying surface-modified specimens are welded at constant chuck rotational speed 1300 rpm. The surface of the AISI304L specimen is buttered with pure aluminium and welded with an AA6063-T6 specimen. Similarly, the faying surface of the AISI304L specimen is tapered and welds with AA6063-T6 specimens having different modifications like a flat, tapered, and internal groove on their faying surfaces. Thus, different welding trials with different friction timings are conducted for each modification. The results of such joining methods like axial shortening, microstructures, EDS spectrums, tensile properties, impact strength, fractography, and Vickers microhardness are discussed and compared in this paper. The surface modifications with friction time improved the strength and 108.8 % joint efficiency.