Surface roughness and energy consumption analysis of conventional and peck drilling approaches

Drilling operations are one of the most commonly used operations in the automotive and aerospace sectors. The aim of this article is to compare peck drilling as an alternate approach to the conventional drilling and reaming operations; in terms of energy consumption and machined surface roughness to facilitate the selection of the optimum finishing processes with respect to machined surface quality and energy consumption. The experiments were performed under dry conditions on an Al-6061 using a high-speed steel reamer and drills of 12 mm diameter. The results revealed that peck drilling refined the surface finish of previously drilled steps in most of the cases. The outcome of the energy consumption analysis was used to evaluate the amount of CO2 emissions. The study suggested that surface roughness refinement in peck drilling was better than conventional drilling but was not as efficient as the reaming process. Peck drilling generated surfaces with a roughness value between those of drilling and reaming operations. Less tool wear was observed under peck drilling process when compared with conventional drilling. The investigation also revealed that CO2 emissions produced under peck drilling approach were slightly higher than for combined drilling and reaming approach.