Experimental Investigation of Cutting Parameters Effects on the Surface Roughness and Tools Wear during the Drilling of Fiber Reinforced Composite Materials

Optimization of the drilling parameters of the composite material is the key objective of this research, enhancing the surface roughness and minimizing the tool wear. In contrary to the other research, optimizing the machining parameters for a specific composite material for the mass productions, machining parameters are optimized for GFRP (Glass Fiber Reinforced Polymer), CFRP (Carbon Fiber Reinforced Polymer) and KFRP (Kevlar Fiber Reinforced Polymer) for the job shop production. In this research, the machining parameters are optimized for the enhanced surface roughness and minimum tool wear by varying the three types of composite material and three levels of the cutting speed. Nine experiments were performed, which were repeated twice in random manner to eliminate the biasness of the results. In these experiments, PVD (Physical Vapor Deposition) coated carbide inserts are used with the same geometry. Seventeen holes were machined in a single experiment, which surface roughness is measured by cutting the composite plate from middle of the hole and using the Countermatic surface roughness meter at different locations. Average surface roughness is determining for each set of varying parameters and plotted to observe the set of parameters for the minimum surface roughness. It has been observed that the minimum surface roughness are observed at; 1500 rpm in GFRP, 2000 rpm in CFRP and at 2500 rpm in KFRP. Finally, the wear patterns are also observed on the drill inserts using SEM (Scanning Electron Microscope) and it has been found that no prominent wear has been observed in the drill inserts, whereas, prominent depletion of coating are found at the higher cutting speed.