Optimization of Process Parameters in CNC Turning of Aluminium Alloy 6061-T6 using Taguchi and Grey Relational Analysis

Abstract

This study presents a systematic investigation into the optimization of CNC turning parameters for Aluminium Alloy 6061- T6 with a focus on minimizing surface roughness (Ra) and tool wear while maximizing material removal rate (MRR). A Taguchi L9 orthogonal array was employed to design experiments with three key process parameters — cutting speed, feed rate, and depth of cut — each at three levels. The experimental results were analyzed using Grey Relational Analysis (GRA) to identify the optimum parameter combination for multi- response optimization. Analysis of Variance (ANOVA) confirmed that feed rate is the most significant parameter influencing surface quality (47.3% contribution), followed by cutting speed (31.6%) and depth of cut (12.4%). The optimal parameter settings were: cutting speed of 200 m/min, feed rate of 0.10 mm/rev, and depth of cut of 0.5 mm. Confirmation experiments validated the predicted optimal settings with an improvement of 18.4% in grey relational grade compared to initial conditions. The findings provide practical guidelines for manufacturing industries employing CNC turning operations on aluminium alloys.