A Taguchi Approach for Evaluating Surface Roughness in Turning of C45 Steel

This study investigates the effects of machining parameters on surface roughness in turning of C45 steel under dry and minimum quantity lubrication (MQL) conditions. The experiments were designed using the Taguchi L8 orthogonal array with four factors, including cooling condition, cutting speed, feed rate, and depth of cut. Surface roughness (Ra) was used as the performance indicator. The results show that Ra values range from 1.12 µm to 1.95 µm. The minimum surface roughness was obtained under MQL with high cutting speed (180 m/min), low feed rate (0.1 mm/rev), and shallow depth of cut (0.5 mm). Signal-to-noise analysis indicates that cooling condition is the most significant factor, followed by feed rate and depth of cut. ANOVA results confirm that these factors significantly affect surface roughness, while cutting speed has a minor influence. The findings demonstrate that MQL improves surface quality and provides an effective approach for enhancing machining performance.