SURFACE ENGINEERING, vol.29, no.4, pp.306-311, 2013 (SCI-Expanded)
In this study, silver particles were embedded in Ni-P matrix by electroless deposition on medium carbon steel substrates to produce Ni-P-Ag composite coating. The structure of as plated and heat treated coatings were evaluated by X-ray diffraction analysis. Tribological properties of the coatings were investigated by pin on disc test method using 52100 steel pin as counter body at room and high temperatures. Three-dimensional optical profiler was employed to determine wear rate of the deposits. Surface morphology, cross-section of coatings and wear scars were studied by using scanning electron microscopy equipped with EDS analysis. The results showed that nanocrystalline Ni-P-Ag composite coating had a self- lubricating property at room and high temperatures. It was concluded that diffusion and nucleation of silver on the surface of Ni-P-Ag coating and also formation of a silver thin layer on the sliding surface led to decrease the friction coefficient of Ni-P-Ag coating.