Effect of chisel edge in ultrasonic assisted drilling of carbon fibre reinforced plastics (CFRP)

Ultrasonic assisted drilling (UAD) has been reported effective for thrust force reduction during drilling of CFRP resulting in lower exit delamination. However, this process is not fully understood in relation to machining theory. This work focused on understanding the separate effects of chisel and cutting edges during UAD in comparison with conventional drilling (CD). Experiments were performed at 100 m/min cutting speed and 0.05 mm/rev feed rate. UAD produced 36% lower thrust force with a chisel edge, similar torque and 35% lower wear on chisel edge compared to CD, suggesting forces from chisel edge specifically, being reduced in UAD. (C) 2016 The Authors. Published by Elsevier B.V.