Improving of the Erosion Corrosion Resistance of the Ni Electro-Coatings by Incorporation of Nano SiC and Diamond Particles

Corrosion and corrosion erosion resistance of Ni-SiC, Ni-Diamond composite and pure Nickel coatings were studied. Variables as current density, stir and particle concentration in the electrolyte were evaluated. Coatings were applied onto steel AISI SAE 1016 substrate by electrodeposition technique using in a Watts solution without additives. Corrosion an erosion corrosion resistance of the coatings were evaluated by electrochemical impedance and open circuit potential monitoring on NaCl and NaCl+SiO₂ solutions. The incorporation of SiC nanoparticles onto Ni matrix improves the microhardness between 20 and 49% (coatings with 20 g/L in the plating bath). When the concentration of SiC increases (70 g/L), the microhardness increase until 133%, however the erosion corrosion resistance diminishes. Low current density and high stir of the solutions also improve the erosion corrosion performance of the coatings. Low diamond particle concentration (10g/L) and high current density and stir improve the erosion corrosion resistance of the Ni-diamond coatings. The Ni-D composite coating show better corrosion-erosion performance than Ni-SiC composite and pure nickel coatings. The Ni-D composite coating gives more protection for steel.