The effect of cutting tool geometry on thrust force and delamination when drilling glass fibre reinforced plastic composite

This work is focused on the investigation of the effect of the cutting tool geometry and material on the thrust force and delamination produced when drilling a glass fibre reinforced epoxy composite. Four drills with distinct geometries and composition were tested. Additionally, the influence of the cutting parameters was studied. Generally speaking, the results indicated that lower thrust force was observed using drill EDP27199, whereas drill A1167A (with three cutting edges) gave highest thrust force values. In contrast to other reports, a direct relationship between thrust force and delamination was not observed, i.e., the drill responsible for the highest thrust force was also responsible for the second smallest delaminated area. Finally, within the cutting range tested the damaged area increased considerably with feed rate and moderately with cutting speed.