Experimental and parametric analysis of friction stir welding on AA 8011-H14 using multi-objective Taguchi-based grey relational analysis for structural applications

Abstract

In this study, Taguchi grey relational analysis (GRA) is employed to optimize process parameters in a multi-objective fashion, aiming to maximize the mechanical characteristics of a 2-mm-thick friction stir-welded AA 8011-H14 aluminum alloy sheet. The experimental design utilized Taguchi's L9 factorial design, varying tool penetration depth, feed speed, and tool rotational speed. The study evaluated output responses, including ultimate tensile strength, yield strength, percentage elongation, and microhardness in the welded region. Macro and microstructure analyses were conducted on the optimized joints at different locations within the welded region. The impact of process parameters on GRA was investigated through analysis of variance. Results indicated that tool rotational speed exerted the most significant influence, followed by tool penetration depth and feed speed, in terms of enhancing output responses. The study also quantified the percentage contribution of each process parameter to friction stir welding.