The influence of TiN coatings properties on cavitation erosion resistance

A series of cavitation erosion tests was carried out to investigate the influence of the TiN coating properties on cavitation resistance. The TiN coatings were deposited at various deposition parameters on austenitic stainless steel, X6CrNiTi18-10, by means of the cathodic arc evaporation method. Investigations were performed in a cavitation tunnel with a slot cavitator. The estimated cavitation resistance parameters were the incubation period and the mass loss. The degradation process of the TiN coatings originates mainly from the plastic deformation of the steel substrate–hard coating system, visible in the microscope as “micro-folding” of the surface. The results of the investigation indicated that the main factors responsible for the cavitation resistance of the steel substrate/hard coating system were the H/E parameter and the coating adhesion. The H/E parameter had an influence on the mass loss while the critical load LC2 was found to have an influence on the mass loss and on the incubation period. Moreover, a good correlation between roughness parameters measured after cavitation test and adhesion was found.