Effects of SiC particles size on electrochemical properties of electroless Ni-P-SiC nanocomposite coatings

Silicon carbide (SiC) nanoparticles were co-deposited by electroless deposition in nickel-phosphorous (Ni-P) acidic bath. In order to understand the size effect of SiC nanoparticles on the electrochemical properties of the coatings, SiC nano particles with different size (20, 50 and 200 nm) in 2 g/L concentration was added to the bath. All samples was heat treated in 400A degrees C in order to obtain crystalline structure. Potentiodynamic polarization and electrochemical impedance spectroscopy was employed to examine of corrosion performance of the coatings. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) were used for phase and morphological studies, respectively. Experimental results show that SiC particles size in the coating bath affected both composition and morphology of the coating. Presence of SiC nanoparticles in the Ni-P coating with 50 nm increased the corrosion resistance of the coating more than the other sizes.