Parametric, Mechanical and Metallurgical Characterization of Dissimilar Friction Stir Welded AA2014-AA2219

Abstract

In this study, Friction stir welding (FSW) is carried out on dissimilar aluminium alloys AA2219 and AA2014 using L16 orthogonal array based on Taguchi Mixed Factorial Design (TMFD) under four process variables: traverse speed, rotational speed, tilt angle and tool profile and the effects of FSW parameters on responses (Tensile Strength, Yield Strength and Elongation) are analyzed using single response optimization and multi-objective Taguchi coupled with Grey Relational Analysis. A parameter setting of A4B4C2D1 is found to be optimal demonstrating 86% of parent material strength. Further, mechanical and metallurgical studies were carried out using SEM, EDAX and XRD analyses. From micro-hardness testing, it was observed that failure occurs at the lower hardness side in the advancing side of AA2219. SEM fractography reveals dispersion of particle which improved weld strength by regulation of coarseness and dissolvability of precipitates in the weld region. EDS point, line and elemental mapping confirmed the presence of copper particle dispersion that acts as a binder and resist void formation, and this is further confirmed by XRD analysis.