Diamond-like carbon coatings on microdrill using an ECR-CVD system

The Ti/TiN/TiCN/DLC multilayer coating on the microdrill was processed in a hybrid PVD-ECRCVD coating system (HBS900). Functionally gradient Ti/TiN/TiCN supporting multilayer was pre-deposited initially on the microdrill in order to improve the adhesion strength of the DLC films. The following dry lubricant coating on it is composed of amorphous, diamond-like carbon (DLC) deposited by ECRCVD plasma in the same recipient. For drilling applications, the combination of hard/soft coating layers, TiN/TiCN/DLC, allows it to improve chip flow with a lowered coefficient of friction and reduced cutting force. In view of further cost reduction, technically the Ti/TiN/TiCN/DLC multilayer coating on microdrill could serve this purpose best. Functionally, in adapting a microdrill coated with DLC film, the quality of hole after inspection was found sufficiently superior than that of uncoated ones, and the drilling lifetime obtained a significant improvement reaching about 2.5 times.