An experimental parameter of cavitation erosion resistance for TiN coatings

A series of cavitation erosion tests were carried out to investigate the resistance of the TiN coatings against cavitation action. The TiN coatings were deposited at various deposition parameters on austenitic stainless steel, X6CrNiTi18-10, with various coating thicknesses by means of the cathodic arc evaporation method (CAVD). Investigations were performed in a cavitation tunnel with a slot cavitator. The estimation of cavitation resistance of the TiN coatings was performed on the basis of the incubation period and the mass loss. The investigations show that coating hardness, Young's modulus, adhesion and coating thickness have an influence on coating endurance to cavitation degradation. The parameter H·LC2/E·h1/2 shows very good fitting to data points (R2 = 0.9707). Along with the increase of the H·LC2/E·h1/2 parameter the mass loss decreases indicating a continuous improvement in the cavitation erosion resistance.

Research highlights▶ The TiN coatings undergo micro-folding at the early stage of cavitation erosion. ▶ The first micro-cracks appeared at micro-folding crests and at delamination spots. ▶ The H·LC2/E·h1/2 parameter shows very good fitting to experimental date points.