Effect of drill point geometry on quality characteristics and multiple performance optimization in drilling of nonlaminated composites

Extensive work has been carried out in the drillability study of thin laminated composites, which are utilized in the light engineering work. Heavy engineering works like construction of bridges, prefabricated platforms, and ballistic applications utilizes thick nonlaminated composites because of its enhanced mechanical properties. Since there is no sufficient literature on the drillability study of thick nonlaminated composites, an experimental investigation has been carried out to study the effect of process parameters on quality characteristics for standard and special geometry design of a drill body. The drilling experiments using carbide drills were conducted using response surface methodology. Special geometry (ratio) drill performs better than the standard geometry (twist) drill. The optimal process parameter levels for twist drill were determined as feed of 0.052 mm/rev and spindle speed of 1059 r/min and that for ratio drill as feed of 0.05 mm/rev and spindle speed of 750 r/min.