Performance analysis of Al stainless steel joints fabricated by friction stir welding: Microstructure, mechanical, and tribology

Abstract

Hybrid structures, incorporating both aluminum and steel, hold potential for applications in automobile, aerospace, and marine industries. This research delves into the effects of friction stir welding on dissimilar joints (AA2024-T3 and SS304), with a focus on microstructural, mechanical, and tribological aspects. The study identifies optimal welding conditions at (tool rotational speed 710 r/min, traverse speed20 mm/min, tool pin offset1.5 mm towards aluminum, and tilt angle of 1.75 deg) that yield a well-defined joint interface, contrasting with flaws observed at a 40 mm/min traverse speed due to insufficient heat input. Under optimal conditions at 20 mm/min, a well-clean serrated interface, defect-free microstructural evolution, improved surface characteristics; enhanced mechanical performance resulting in higher ultimate tensile strength of 319 MPa with joint efficiency of 72.5 and better tribological performance were achieved with lower wear rate of 1.1607 × 10−5 g/Nm compared to those at 40 mm/min, highlighting the crucial role of optimized friction stir welding parameters in achieving high-quality dissimilar joints with desirable properties.