Minimization of Temperature in Cutting Zone: A Case Study of Hard Milling of SKD 61 Steel

The heat generated during metal cutting is a major factor affecting the cutting forces, tool life, and chip formation mode. In this research, the Taguchi method was applied to find the optimal values of cutting parameters in hard milling of SKD 61 steel to minimize cutting temperature under cutting oil and Al2O3 nanofluid - MQL condition. The effects of cutting parameters including cutting speed, feed rate and depth of cut were investigated by using an L9 array of Taguchi method. The signal-to-noise (S/N) ratios and analysis of variance (ANOVA) were applied to analyze the influence of input factors on the cutting temperature. The study result shows that cutting speed is the most influential factor, which gives statistic significant effect on cutting temperature. The speed contributes 52.55 % of total effect under cooling condition of MQL with cutting oil and 53.77 % of total effect under cooling condition of MQL with Al2O3 nanofluid. Additionally, the effectiveness in cutting heat reduction of cutting oil - MQL was compared with Al2O3 nanofluid - MQL based on experimental measurement of cutting temperature. According to the analysis, the Al2O3 nanofluid – MQL is a better option for the cooling conditions during hard milling of SKD 61 steel.