Testing and design of tool coatings with properties adapted to the use of biodegradable cutting fluids

The paper focuses on defining demands on tool coatings developed for use wi th biodegradable cutting fluids, presenting new coating systems and researc h results on necessary coating functionalities which match these technologi cal demands. Coating development and a tribological test scheme for the rea lisation of high tribo-oxidation stability is also described. The scope for improving the anti-adhesive properties of coatings for drilling tools are outlined. This covers the physical characterisation of surface polarity and surface energy of PVD hard coatings and the behaviour of nano-layered WC/C -coatings in the drilling of austenitic stainless steel.