Effects of TiO2 particles size and heat treatment on friction coefficient and corrosion performance of electroless Ni-P/TiO2 composite coatings

The effects of the titanium dioxide (TiO₂) particles size on the friction coefficient and corrosion performance of the Ni-P/TiO₂ composite coatings before and after heat treatment at 400°C for 1h have been investigated. Pin-on-disc analysis results have revealed that the highest and the lowest friction coefficients belonged, respectively, to the simple Ni-P coating and the Ni-P/TiO₂ composite coating containing TiO₂ particles of the average size of 0.1 μm (μ ～ 0.62 against 0.52). Eventually, a relative reduction in the corrosion resistance and the friction coefficient (as low as μ ～ 0.38) have been observed after heat treatment of Ni-P and Ni-P/TiO₂ composite coatings.