Cavitation erosion resistance of Ti/TiN multilayer coatings

The degree of cavitation erosion was estimated by mass measurements and surface roughness measurement tests. The value of surface roughness of the Ti/TiN-4 coating was closest to that of the uncoated steel. The surface profiles of the Ti/TiN-12 and Ti/TiN-40 coatings showed little undulation, not visible in the profiles of the Ti/TiN-4 coating and the uncoated X6CrNiTi18-10 steel. The microscopic observation showed that deformation of the multilayer coatings developed via cracking, which further propagated by simultaneous fracture of numerous coating layers.