Drilling is a common machining process in manufacturing industries, where proper process parameter selection plays a significant role in controlling machining forces and achieving desirable surface quality. In this study, the effects of drill diameter, cutting speed, and feed rate on axial force, torque, and surface roughness during drilling of AA6082-T6 aluminum alloy were experimentally investigated. The experiments were designed using Response Surface Methodology (RSM) and Central Composite Design (CCD). Following the experiments, the effects of process parameters on the responses were evaluated using main effects plots and sensitivity analysis.



The results showed that increasing drill diameter and feed rate increased axial force and torque, whereas increasing cutting speed reduced both responses. The process parameters also significantly affected surface roughness, with feed rate identified as an important factor influencing surface quality. Sensitivity analysis revealed that drill diameter was the most influential process parameter among the investigated variables, accounting for approximately 83%, 82%, and 71% of the variations in axial force, torque, and surface roughness, respectively. In addition, feed rate, with a contribution of 23%, showed the second-highest influence on surface roughness after drill diameter.



Based on the obtained results, drill diameter can be considered the dominant process parameter, playing a determining role in the mechanical responses and surface quality of drilled AA6082-T6 alloy. Quantifying the relative contributions of process parameters provides a better understanding of drilling behavior and can support the selection of appropriate machining conditions for controlling machining forces and improving surface quality in industrial applications involving aluminum alloys.