Corrosion behaviour of compositionally modulated nanocrystalline Ni-W coatings

The present study deals with corrosion behaviour of compositionally modulated nanocrystalline Ni-W alloy coatings and conventional hard chrome coatings. Compositionally modulated Ni-W alloy coatings of known composition were systematically deposited using pulse current deposition. The corrosion behaviour was analysed using potentiodynamic polarization and impedance spectroscopy in 2N H2SO4. Compositionally modulated Ni-W alloy coatings depicted substantial improvement in corrosion resistance over its single-layer counterpart and hard chrome coatings. The corrosion behaviour was rationalized based on porosity and surface residual stresses present in these coatings.