Optimization of friction stir welding process parameters for weld strength of Inconel 625 parts using genetic algorithm

Abstract

This research work presents a systematic optimization of friction stir welding (FSW) parameters for the solid-state welding of Inconel 625 alloy using Tungsten carbide tool material. Employing an L9 orthogonal array with three factors and three levels, the study explored nine distinct input parameter combinations and its effect on weld strength. Taguchi analysis unveiled the optimal parameters, emphasizing a tool rotational speed of 300 rpm, welding speed of 115 mm/min, and axial force of 18 kN, in adherence to the 'larger the better' criterion. Notably, the rotational speed exerted a significant influence on joint weld strength, with 300 rpm emerging as the optimal choice. The Genetic Algorithm-based refinement further validated these parameters, resulting in a remarkable maximum weld strength of 403.7 N/mm2. Experimental validation of the model accentuated the efficacy of employing a rotational speed of 300 rpm, welding speed of 115 mm/min, and axial force of 18 kN, culminating in a maximum weld strength of 407 N/mm2. These findings establish a robust parameter combination for achieving superior weld strength in Inconel 625 through the utilization of Tungsten carbide as the tool material in the Friction Stir Welding method.