Multi-hole simultaneous drilling of aluminium alloy: A preliminary study and evaluation against one-shot drilling process

Poly-drill heads are used in mass production to increase productivity when a large number of holes are required. In this work, drilling experiments on Al5083 aluminium alloy were carried out using a poly-drill head to measure the thrust force and assess hole quality. Analysis of chip formations and post-machining tool condition were evaluated using optical microscopy. Additional drilling tests were conducted using one-shot drilling and results obtained from the two drilling techniques were evaluated against each other. The results showed that the average thrust forces obtained from poly-drill head were slightly lower than those from one-shot drilling. Improvement in hole quality in terms of surface roughness and reduction in chip length were achieved using the poly-drill head. Furthermore, visual inspection of the tools showed that adhesion and built-up edges on drills used in the polydrill head were lower as compared to drills used in the one-shot drilling. The contribution of input parameters on the measured outputs was determined using an ANOVA statistical tool. (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0%).