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, diamondlike 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.