Surface roughness analysis in the drilling of carbon fiber/epoxy composite laminates using hybrid Taguchi-Response experimental design

The carbon fiber reinforced polymer composite has made a substantial impact on the manufacturing sectors owing to its excellent mechanical, thermal and corrosion resisting properties. The surface roughness mainly depends on the machining parameters while drilling of carbon fiber reinforced polymer composite laminates. The study concentrates on the impact of uncoated and titanium nitride coated solid carbide drills on minimizing the roughness that is generated while making holes in bi-directional carbon fiber reinforced polymer composite by optimizing the drilling constraints [spindle speed (A), feed rate (B), point angle (C) and drill diameter (D)]. Experimental studies are carried out using Taguchi L ₂₇orthogonal array. The investigation discloses that the drill diameter is one of the most influencing cutting parameters followed by spindle speed and feed rate. The response surface methodology is chosen as a tool for predicting and optimizing the process parameters. The investigation also discloses that the experimental and the predicted results of surface roughness are closely matching with each other. The surface morphology illustrates that titanium nitride coated solid carbide drills minimize the surface roughness compare to that of uncoated solid carbide drills.