Wear and corrosion behaviors of Ni-B-TiN MMCs produced with pulse co-electrodeposition

In this study, novel Ni-B-TiN metal matrix composite (MMC) coatings were successfully produced using a pulse current deposition (PED) method using a nickel Watt bath containing TiN nanoparticles. The main purpose is to provide the deposition optimization (particle concentration, current density, and duty cycle) of the Ni-B-TiN composite coating and morphology, mechanical, tribological and corrosion properties of composite coatings. The suspension of TiN particles in the electrolyte was investigated by the zeta potential technique. The morphologies deposited in the coating surface and cross-sections were analyzed by worn surfaces scanning electron microscope (SEM) and a composite coating with a smooth, dense, and smooth surface was obtained. Phase structures of the deposited layers were analyzed by X-ray diffraction (XRD). By using X-ray diffraction (XRD) models, the crystallite size and lattice distortion of the coatings were calculated. The Ni-B-TiN composite coatings deposited on the substrate were heat treated at 400oC for 1 h to improve the mechanical properties and to provide intermetallic precipitation. XRD results showed that Ni (111) phase is dominant and Ni2B, Ni3B and TiN phases are formed. Nano-indentation hardness tests were performed on the cross-sections of the coatings and piston ball disc tests were performed for tribological measurements. Wear tests were performed under 5N load at room temperature (25oC), in 45 ± 2% relative humidity environment and the results were examined. The wear test results showed that the coefficient of friction and wear rate of the coating decreased. The corrosion properties of the coatings were examined in wt. 3,5% NaCl solution and electrochemical impedance spectroscopy (EIS) was also applied. Microstructures, coating thickness, mechanical properties, tribological and corrosion tests have shown that the co-deposition of Ni-B-TiN composite coating mechanisms is managed by the absorption model of Gugliemi. In this study, novel Ni-B-TiN metal matrix composite (MMC) coatings were successfully produced using a pulse current deposition (PC) method using a nickel Watt bath containing TiN nanoparticles. Based on this model and experimental results, the TiN particle content in the 15 g/L electrolyte was shown to be the optimum concentration to achieve the best properties at 4,5 A/dm2 current density and 40% duty cycle.