Multilayer Structure Dependent Performance Behaviour of CVD Diamond Thin Film Drilling Tools During CFRP Machining

The potential of chemical vapor deposition (CVD) diamond coated tools in its application for machining lightweight materials, such as carbon fibre reinforced plastics (CFRPs), is currently limited to coating adhesion failure. Resulting spontaneous delamination and subsequent critical tool wear adversely affect the reproducibility of tool lifetime, process stability as well as machining quality. Although different morphologies and its variation of layer thicknesses on geometrically complex tools can be deposited, the interaction of coating and substrate determines the overall cutting tool strength. In addition, influencing factors on coating adhesion generated by the manufacturing process, such as tool substrate production and coating parameters, cause a high variance with regard to the cutting tool performance even within one tool batch.