Taguchi Optimization of Cutting Temperature in C45 Steel Turning under Dry and MQL Machining

This study investigates the effects of cooling condition, cutting speed, feed rate, and depth of cut on cutting temperature during the turning of C45 steel using a carbide cutting tool. A Taguchi L8 orthogonal array was employed to design the experiments under dry and minimum quantity lubrication (MQL) conditions. The experimental results were analyzed using signal-to-noise (S/N) ratios and analysis of variance (ANOVA). The results indicated that cooling condition was the most influential factor, contributing 98.1% to the total variation in cutting temperature, followed by cutting speed (1.7%). MQL significantly reduced cutting temperature from 189–215 °C under dry machining to 64–81 °C. The optimal parameter combination for minimizing cutting temperature was identified as MQL cooling, a cutting speed of 120 m/min, a feed rate of 0.1 mm/rev, and a depth of cut of 0.5 mm. The findings demonstrate the effectiveness of MQL in controlling cutting temperature during turning of C45 steel.