Salt water corrosion resistance of electrodeposited Ni-layered silicate nanocomposite coatings from Watts' type solution

Abstract

Pure nickel and nickel-montmorillonite (Ni-MMT) composite coatings were produced using pulse current electrodeposition from Watts' type solution. Experimental results show that the codeposition of MMT particles into the Ni matrix improves the microhardness of the coatings and modifies the [100] texture of pure Ni deposits to a mixed crystal orientation through [100] and [211] axes. Ni-MMT composite coatings show improved corrosion resistance in simulated seawater as compared to pure Ni as revealed from electrochemical polarization and impedance measurements. SEM and AFM micrographs indicate a reduction in the Ni crystallite grain size and increase in the surface roughness of the film as a result of embedding of MMT particles in the Ni matrix.