Investigation on thrust in vibration drilling of fiber-reinforced plastics

The anisotropy of fiber-reinforced plastics (FRPs) affects the chip formation and thrust during drilling. Using a carbide drill and a high-speed steel (HSS) drill, a series of vibration drilling and conventional drilling experiments are conducted on glass fiber-reinforced plastic composite (GFRP), carbon fiber-reinforced plastic composite (CFRP) and printed circuit board (PCB). Along with the increasing of the drill axial displacement, a continuous decrease of thrust force has been found. It is due to the generation and the accumulation of material fractures and cracks. The experimental results show that the thrust of vibration drilling is smaller than that of conventional drilling, which indicated that the vibration drilling method is appropriate for producing microholes on FRPs.