Sustainable turning using multi-objective optimization: a study of Al 6061 T6 at high cutting speeds

The objective of this study is to determine optimum machining parameters during high-speed turning (up to 1500 m/min) of Al 6061 T6 alloy. The chosen machining parameters optimize the trade-off between three competing responses: specific cutting energy, material removal rate, and surface roughness. These responses were first analyzed independently to establish their conflicting nature. Individual responses were then combined to formulate a multi-objective function using gray relational analysis augmented with analytic hierarchy process. Multi-objective function was optimized using regression analysis and response surface optimization. Analysis of variance results revealed cutting feed to be the most significant machining parameter affecting multi-objective function, followed by cutting speed and depth of cut. The proposed machining parameters resulted in reduction of specific cutting energy by 5% and an improvement of 33% in material removal rate while surface roughness remained unaffected.