Influence of Heat Treatment on Properties of Ni-B/B Composite Coatings

The results of research on preparations of alloy Ni-B/B composite coatings produced by chemical reduction method on a carbon steel substrate are collected in this paper. The alloy Ni-B coatings were also investigated for comparative purposes. The produced coatings were subjected to a heat treatment process. The boron powder with the particles size below 1 μm was used as the dispersion phase. The structure of the coatings was examined by X-ray diffraction method. Boron powder particles as well as surface morphology and topography were characterized by scanning electron microscopy. The roughness test, microhardness and corrosion resistance by potentiodynamic method and surface wettability tests were carried out. Analysis of the chemical composi-tion by the EDS method showed that the boron powder particles were evenly embedded in the entire volume of the coating. Ni-B/Bcomposite coatings are characterized by higher hardness than alloy Ni-B coatings. As a result of heat treatment, the Ni3 B phase crystallized, which increased the hardness of the coating material. The incorporation of boron powder particles and heat treatment reduce the corrosion resistance of coatings. All produced coatings exhibited hydrophobic properties