Multi‐Objective Optimization and Corrosion‐Mechanical Analysis of AA2014‐T6 Alloy in Friction Stir Processing Using Taguchi‐Grey Relational Approach

This study uses friction stir processing (FSP) to enhance the mechanical characteristics and corrosion resistance of AA2014‐T6, an area that has often been overlooked in earlier research. Taguchi‐Grey Relational Analysis and advanced multi‐objective optimization are used to determine the optimal balance under different process conditions. The research focuses on grain refinement and reduced grain boundary precipitates to enhance tensile strength, hardness, and elongation while improving corrosion resistance via fine grains and reduced secondary phase content. Machinability under drilling is also evaluated. Ideal FSP parameters (1000 rpm, 60 mm/min feed, 2° pivot) produced a GRG value of 0.876, confirming performance improvements.