According to the idea of sustainable development, humanity should make every effort to care for the natural environment along with economic development. Decreasing water resources in the world makes it necessary to take action to reduce the consumption of this resource. This article presents the results of research conducted to improve the use of recyclable materials in line with the circular economy model. The research focused on the development of a technological solution for the recovery of raw materials from galvanic wastewater. The concept of a galvanic wastewater treatment system presented in the article includes wastewater pre-treatment in the ultrafiltration (UF) process and water recovery in the reverse osmosis (RO) process. In addition, the purpose of the work was to manage post-filtration waste (RO retentate) containing high concentrations of zinc in the process of galvanizing metal details. The obtained results indicate that it is possible to reduce the amount of sewage from the galvanizing industry by reusing the recovered water as technical water in the process line. The carried-out model tests of galvanizing confirmed the possibility of using RO retentate for the production of metal parts. The achieved results are a proposal to solve the problem of reducing the impact of galvanic wastewater on the environment and to improve the profitability of existing galvanizing technologies by reducing the consumption of water and raw materials.

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.

Composite coatings have been successfully fabricated at the laboratory scale in many research centers around the world; however, it is still a major challenge to transfer the positive results of the work to the industrial scale. This paper presents the technology for the production of Ni-B and Ni-B/B composite coatings on a pilot experimental semi-technical line by chemical reduction. A process scheme for the fabrication of Ni-B layers and composite coatings with a nickel–boron matrix and a dispersive phase in the form of boron nanoparticles was developed. All stages of the fabrication process were described in detail. The dispersion phase of the boron particles was characterized, and the performance properties of the Ni-B and Ni-B/B composite coatings produced on a pilot electroplating line were studied. The structure and morphology of the Ni-B/B composite coatings were characterized for comparison with nickel–boron coatings. Their mechanical and tribological properties and adhesion to the substrate were studied. The influence of the dispersion phase of boron particles on the structure and functional properties of the composite coatings was evaluated. In order to improve the performance of the fabricated coatings, a heating process at 400 °C was carried out, and the performance of Ni-B and composite Ni-B/B coatings was studied after the heat treatment operation.

This article presents Cu/diamond composite coatings produced by electrochemical reduction on steel substrates and a comparison of these coatings with a copper coating without diamond nanoparticles (<10 nm). Deposition was carried out using multicomponent electrolyte solutions at a current density of 3 A/dm² and magnetic stirring speed of 100 rpm. Composite coatings were deposited from baths with different diamond concentrations (4, 6, 8, 10 g/dm³). This study presents the surface morphology and structure of the produced coatings. The surface roughness, coating thickness (XRF), mechanical properties (DSI), and adhesion of coatings to substrates (scratch tests) were also characterized. The coatings were also tested to assess their solderability, including their spreadability, wettability of the solder, durability of solder-coating bonds, and a microstructure study.