Post-Coating Treatment of Cutting Edge for Drilling Carbon Fibre Reinforced Plastics (CFRP)

Abstract

Drilling of highly abrasive carbon fibre reinforced plastics (CFRP) requires carbide tools with geometrical highly adaptable tool geometries andwear resistant diamond coatings. To counteract the tradeoff between long tool lifetime by preferably thick diamond layers leading to largecutting edge radii (bluntness), and the sharpest possible cutting edge to generate flawless machining qualities, the following post-coatingcutting edge treatment methods are compared: Laser-ablation and selective sandblasting. It is shown that laser treatment generates cutting edgeradii of 3-4 μm leading to outstanding bore exit qualities in CFRP from the first bore on, while diamond still protects the rake face.