Factors Affecting Workpiece Surface Integrity in Slotting of CFRP

CFRP use in aerospace applications has seen a dramatic increase over the last decade. The slotting/routing process is used to trim excess material from cured CFRP panels in wing manufacture. The work presented details the effect of different slotting parameters, tool materials (WC & PCD) and cutting environment (chilled air & dry) on the surface roughness and integrity of machined CFRP laminates when employing an L16 fractional factorial Taguchi experiment. Scanning electron micrographs and 3D topographic maps show the influence of fibre orientation with respect to the cutting direction. Thermal damage (burning & resin melt) were minimised using chilled air. Use of PCD tooling provided significantly increased productivity compared to coated WC with workpiece surface roughness of ∼3.6μm Sa at 200m/min cutting speed and 0.03mm/tooth feed rate.