Electrochemical and mechanical characterization of composite Ni/SiC coatings produced by electrodeposition on XC45 steel

The need to improve coatings for better properties leads to the development of composite electrolytic deposition, by the incorporation of solid particles in the nickel structure. The aim of this work is to produce a composite coating nickel / silicon carbide (SiC) with a high hardness and a good chemical stability. The coating is performed in a Watts bath of electroplating chloride, consisting of an electrolytic nickel matrix (binder) with different concentrations of silicon carbide microparticles (mean diameter 0.8 μm). The coating analysis is performed by X-ray diffraction, by atomic force microscopy (AFM) and by scanning electron microscope (SEM). The characterizations of the deposited layers are carried out in 3.5% NaCl solution. The weight loss, the polarization and the microhardness results highlighted a silicon carbide concentration SiC which can be included in the overall expression of a good composite coating. This concentration improves the corrosion resistance and the microhardness.