Influence of particle size and content on the friction and wear behaviors of as-annealed Ni–Mo/diamond composite coatings

Abstract Ni–Mo/diamond composite coatings have been electrodeposited in a Ni–Mo electrolyte containing micron diamonds with five different sizes, respectively. The diamond content in coatings is in the range of 5–31 vol%. The grain size of as-annealed coatings is smaller than 10 nm. Microhardness of as-annealed coatings increases with the diamond content, and the highest hardness is about 15.4 GPa. The as-annealed coatings incorporated with 5 μm diamonds have supvderior wear resistance to that of the other coatings. The lowest wear rates of the as-annealed coating and the pin-on-disk system are about 2 × 10−6 and 5 × 10−6 mm3 N−1 m−1, respectively, which all correspond to the coating containing 31 vol% diamonds with the size of 5 μm.