Study on Corrosion Resistance and Tribo Behavior of Electrodeposited Ni-W-P/TiN Composite Coatings

In this paper, a pulse electrodeposition technique is employed to introduce superhard nanoscale titanium nitride (TiN) particles into the Ni-W-P coating. Moreover, the work extensively examined the impact of varying TiN nanoparticle concentrations on the Ni-W-P coating's performance. The findings reveal that the introduction of TiN effectively fills the crevices and other imperfections present on the pristine plating layer's surface, improving the aggregation of grains. The incorporation of TiN nanoparticles, owing to their "labyrinthine effect" and grain refinement capability, notably enhanced the mechanical performance and corrosion resistance of the pure coating. Optimal results are achieved, showcasing superior mechanical attributes and corrosion defense, when the TiN concentration in the bath reaches 4 g/L. Vickers microhardness testing unveils that the Ni-W-P/TiN composite coating, at a TiN loading of 4 g/L, observes its microhardness escalating from 496.6 HV for the pure Ni-W-P coating to 847.6 HV. In a reciprocating friction assessment, the mean friction coefficient diminishes, plummeting from 0.663 for Ni-W-P to 0.325. Regarding corrosion tolerance, the Ni-W-P/TiN (4 g/L) composite coating demonstrates the greatest capacitive arc radius, alongside a corrosion current density diminishing from 26.0 mu A/cm2 (Ni-W-P coating) to 11.93 mu A/cm2 compared to the unaugmented Ni-W-P coating. Additionally, the self-corrosion potential shifts positively, going upward from -0.536 V for the Ni-W-P coating to -0.323 V. It is further established that the Ni-W-P/TiN composite at 4 g/L surpasses the Ni-W-P coating in corrosion resistance capabilities.