Properties of Ni-B/B Composite Coatings Produced by Chemical Reduction

Abstract

The paper presents the results of research on composite Ni-B coatings with embedded particles of boron produced by a chemical reduction method and their influence on the mechanical, tribological, and corrosion properties of produced materials. Boron was used in two forms: an alloy component and nanoparticles incorporated into the Ni-B matrix. The coatings were deposited from a bath at different concentrations of dispersion phase. The paper also presents the characteristics of the used boron particles. Results of morphology and surface topography (SEM) as well as the structure (XRD) of the produced coatings are presented. The mechanical properties of the produced coatings, like Knoop hardness, Martens hardness, and indentation hardness, as well as the modulus of elasticity, were determined. The tribological tests were carried out using the ball-on-disc method. Electrochemical corrosion tests were conducted by the potentiodynamic method. The adhesion of the coatings to the substrate was evaluated by the scratch test method. Consequently, this investigation yielded a novel material in the form of Ni-B/B composite coatings, exhibiting significantly improved mechanical and tribological properties compared to Ni-B coatings without embedded particles of the dispersion phase.

Properties of Ni-B/B Composite Coatings Produced by the Electroless Method under Semi-Technical Line Conditions

“…Boron in the coating exists in two forms: as a component of the alloyed Ni-B matrix and as a particulate dispersion phase that is incorporated into it. The team's previous work [9] on this type of coatings was carried out on a laboratory scale in beakers (0.5-2 dm 3 ), and their main goal was to determine the conditions for proving the deposition process and the concentration of the dispersion phase (boron) in the electro- To date, research on Ni-B alloy coatings produced electroless has involved laboratoryscale tests in beakers and vessels with capacities ranging from a few hundred cm 3 to a few dm 3 . However, there is a lack of information in the literature on the production of this type of material on an engineering scale in industrial, i.e., close to real, conditions.…”

“…Boron in the coating exists in two forms: as a component of the alloyed Ni-B matrix and as a particulate dispersion phase that is incorporated into it. The team's previous work [9] on this type of coatings was carried out on a laboratory scale in beakers (0.5-2 dm 3 ), and their main goal was to determine the conditions for proving the deposition process and the concentration of the dispersion phase (boron) in the electrolyte at which the properties of the coatings are best. Laboratory tests showed that for a given type of coatings, the most beneficial tribological, mechanical and corrosion properties were obtained for coatings deposited from baths containing 1 g/dm 3 of boron powder as the dispersion phase (TRL 4).…”