Mono-objective and multi-objective optimization of performance parameters in high pressure coolant assisted turning of Ti-6Al-4V

This paper presents the optimization of cutting forces, average surface roughness, cutting temperature, and chip reduction coefficient in turning of Ti-6Al-4V alloy under dry and high pressure coolant (HPC) that is applied at the rake and flank surfaces simultaneously. The experimental design plan was conducted by the full factorial parameter orientation. The optimization has been conducted in two ways: firstly, by using signal-to-noise ratio-based Taguchi method as mono-objective optimization; secondly, by using gray relational analysis integrated with Taguchi method as multi-objective optimization. In either method, the cutting speed, feed rate, and cutting condition were considered as the inputs to the optimization. The mono-objective optimization concluded that the 156 m/min cutting speed and 0.12 mm/rev feed rate when run under HPC optimized the cutting forces and roughness, and when operated under dry optimized chip reduction coefficient, the cutting temperature was minimized at 78 m/min and 0.12 mm/rev feed rate. The multi-objective optimization concluded that Ti alloy turning system is optimized at 156 m/min cutting speed and 0.12 mm/rev feed rate under HPC.