Taguchi-Based Optimization of Drilling Parameters for Minimizing Burr Height and Surface Roughness in Dry Drilling of Al-6063 Aluminum Alloy

Abstract

Hole quality is a critical factor affecting the dimensional accuracy, structural integrity, and service performance of machined components. This study experimentally investigates the influence of cutting speed and feed rate on surface roughness, entry burr height, and exit burr height during the dry drilling of Al-6063 aluminum alloy using a high-speed steel (HSS) twist drill. A Taguchi L9 orthogonal array was employed to design the experiments, while signal-to-noise (S/N) ratio analysis was used to evaluate the significance of the machining parameters and identify the optimum drilling conditions. Drilling experiments were conducted at three cutting speeds (700, 880, and 1400 rpm) and three feed rates (0.10, 0.20, and 0.30 mm/rev) under dry machining conditions. The experimental results revealed that both cutting speed and feed rate significantly influence hole quality. Surface roughness increased with increasing cutting speed and feed rate, with cutting speed identified as the most influential parameter. Feed rate was found to be the dominant factor affecting both entry and exit burr heights. The poorest drilling performance occurred at the highest cutting speed (1400 rpm) and feed rate (0.30 mm/rev), producing the maximum surface roughness (2.818 μm), entry burr height (2.446 mm), and exit burr height (2.425 mm). Conversely, the combination of a low cutting speed (700 rpm) and a low feed rate (0.10 mm/rev) yielded the best overall hole quality with minimum burr formation and superior surface finish. The optimized machining conditions identified in this study can improve product quality, reduce deburring operations, and support environmentally sustainable dry drilling of Al-6063 aluminum alloy.