Investigations of Multifunctional Graded Zirconium Carbide PVD-Coatings for the Application on Machine Parts

An efficient way to reduce energy consumption and costs of machines is to reduce the friction in tribological systems such as gear wheels, spindle bearings and regular ball bearings. Tribological PVD (Physical Vapour Deposition)-coatings have thus been developed at the Materials Science Institute in the context of the special research project SFB 442 named “Environmentally Compatible Tribosystems”. The main challenge facing PVD applications is the complex geometry of machine parts as well as the low deposition temperature. Therefore, the use of Magnetron Sputtering Ion Plating (MSIP-PVD) offers the advantage of producing coatings with a much wider range of properties. A superstoichiometric coating with an over saturated amount of carbon is adjusted by PVD parameters. This creates a shear-weak top coating with a low friction coefficient and a self smoothing surface. The coatings were analysed in standard tests such as the calo-test, scratch-test and HRC-test. Furthermore, the nanoindentation and SEM observations proved a clear correlation between chemical composition and physical properties.