INFLUENCE OF DIFFERENT PRODUCTION PARAMETERS ON THE FUNCTIONAL-BEHAVIOR OF TOOLS AND PARTS AFTER COATING

The efficiency of using wear-resistant coatings for tools and componen t depends considerably on the adhesion between the coating and the sub strate. Therefore we investigated how different production parameters of the substrate influence the functional behaviour of tools and machi ne parts after coating. Before coating by physical and chemical vapour deposition processes (PVD, PACVD and CVD), the surfaces of tools and parts were differently machined to obtain different rougnesses, topogr aphies and residual stresses in the substrate. The surfaces were inves tigated by modern surface analysis (SEM, AES, ESCA) in order to detect coating defects and to obtain information about the chemical composit ion of the coated surface or the coating itself. Finally, the function al behaviour was checked by cutting, forming and model wear tests unde r laboratory and field conditions. Applied tests with vane pumps were also carried out. The examination of the results of all the tribologic al tests shows that the functionals behaviour of coated model wear spe cimens, tools and parts depends strong on the surface conditions of th e substrate before coating. According to the type of stressing differe nt surface pre-treatments are recommended. The tribological behaviour is influenced by the interaction of many different parameters, such as the surface roughness and topography and the residual stress in the c oating and substrate. With optimized surface pre-treatment of the subs trate, the life of coated tools or parts can be increased considerably .