Effects of Welding Parameters in Friction Stir Welding of Stainless Steel and Aluminum

Abstract

Joining of dissimilar materials (DMs) is the growing demand of various industries to attain distinct features of individual material. In this regard, friction stir welding (FSW) has emerged as a unique joining method to weld DMs among various joining techniques. FSW is a solid-state welding process used to join similar and dissimilar materials (DMs). In this study, DMs AA7475-T761 aluminum alloy (AA) and AISI 304 stainless steel (SS) are joined using FSW. These DMs are widely lap welded in industries such as space shuttles and aerospace. Friction stir welded (FSWed) half-lap joints are obtained and analyzed under three different tool rotation speeds: 450, 560, and 710 rpm. The joint quality is analyzed by tensile strength and microstructure. The improper heat generation at different tool rotation speeds affected joint quality considerably. The defects such as tunneling and void were observed which resulted in poor efficiency of joints. The joint efficiency was obtained maximum 62.83% of the base material (BM) AA 7475 at rotational speed 560 rpm with 6.89% elongation.