BEHAVIOR OF LIGHT-METALS WITH PVD-CRN COA TINGS USING DIFFERENT TEST METHODS

The application of thin hard coatings on machining tools, e.g. drillin g tools is state of the art. The increase of lifetime of coated tools compared to uncoated tools is well known. [1]. In this context ''separ ation of functions'' is an often used phrase, by meaning the separatio n of functions of the volume and the surface of materials. Going one s tep forward, from the point of view of tribology or corrosion this mea ns, you have ''only'' to protect the surface by using a ''good'' coati ng without looking at the material underneath. In the past the influen ce of substrate materials or the optimization of the system (substrate -coating) was not the main aim of PVD development. Looking at substrat e and coating as a system is especially necessary, if the differences of the properties of substrate and coating are large (e.g. hard coatin g - light metals).This paper shows different aspects of the tribologic al and electrochemical characterization of PVD coated light metals (Cr N coating).