Simultaneous Optimizing Surface Roughness and Cutting Time in MQL Face Milling of Hardened SKD11 Using Response Surface Methodology

This paper investigates the simultaneous optimization of surface roughness (Ra) and cutting time (Tc) in the face milling process of hardened SKD11 using the Minimum Quantity Lubrication (MQL) technique and Response Surface Methodology (RSM). The objective is to identify optimal machining parameters that can achieve the best surface roughness while minimizing the cutting time. A series of experiments were conducted, and the RSM was employed to analyze the data and establish a mathematical model. The results revealed that cutting speed (Vc), depth of cut (ap), and feed rate (fz) significantly influenced surface roughness and cutting time. Through the optimization process, the optimal machining parameters were determined to be a cutting speed of 60 m/min, a depth of cut of 0.1 mm, and a feed rate of 0.054706 mm/min. When these parameters were applied, the achieved surface roughness was 0.126179 μm (Ra) and the cutting time was 9.88514 seconds (Tc). These values represent a notable improvement compared to conventional machining parameters. The findings demonstrate the efficacy of the proposed MQL and RSM approach in simultaneously optimizing surface roughness and cutting time. By utilizing the optimal machining parameters, manufacturers can enhance productivity and product quality in the face milling process of hardened SKD11. Furthermore, the research contributes to the understanding of the effects of MQL and the importance of parameter optimization in achieving superior machining performance