Cavitation erosion of electroplated nickel composite coatings

The cavitational wear resistance of electroplated nickel composite layers was tested following ASTM G32. Particles of different hardness (titania and silicon carbide) and different sizes from micro-scale to nano-scale were incorporated up to 30 vol.% into a nickel matrix. Martens hardness is improved by grain refinement via particle incorporation. Compared to pure electroplated nickel films the composite layers strengthened by submicro-scale silicon carbide particles exhibit a decreased mass loss of one order of magnitude after 8 h testing time. Remarkably, layers with nano-scaled titania particles show a similar performance. from particle adherence failures, reduced mass loss of the composite layers correlate with improved hardness of the composite due to grain refinement of the matrix and dispersion hardening effects.