Electrochemical investigations of Ni-P/nano c-BN deposited on aluminum alloy

Abstract

Electrochemical investigations were carried out on the Ni-P/nano cubic-Boron Nitride (c-BN) coatings obtained by using sodium hypophosphite reduced electrolyte bath solution with complexing agents. The screening of complexing agents was carried out by UV-Visible spectrophotometric studies. The deposits obtained using optimized bath composition was tested by EDAX, SEM and XRD in order to understand the structural morphology of the coatings. Electrochemical studies conducted by Potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) reveled the greater stability of coatings in acidic and alkaline environment. To evaluate the behavior of the coatings in marine environment, Salt spray test was conducted using sodium chloride solution. Results indicate the improved resistance to corrosion with the incorporation of nano c-BN in the coatings.

Keywords

• cubic-boron nitride
• corrosion resistance
• polarization
• eis
• salt spray