International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Thin coatings of zirconia oxide (ZrO2) and samarium oxide (Sm2O3) on glass have been prepared by using sol-gel method and dip coating technique. Materials were characterized in detail by X-ray diffraction. The luminescent properties at room temperature were also investigated. Excitation and emission spectra of ZrO2 coating consists of broad bands with maximums at 318 and 365 nm respectively.
The photoluminescence measurements of samarium coating suggest that can be efficiently excited with 700 nm and consist of emission bands centered at 567, 603, 639 and 707 nm, consistent with characteristic Sm3+ transitions. The CIE (Commission Internationale de L’Eclairage) chromatic coordinates, color purity and color correlated temperature were determined.

One-component CeO2 coatings and bi-component CeO2/ZrO2 multilayer coatings were obtained by a sol gel process. The phase composition, surface morphology and roughness of the samples were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Atomic force microscopy (AFM) and X-ray scanning electron microscopy (XPS). The corrosion resistance and protective ability were characterized by using salty solution of 3.5% NaCl at 25 C. The multilayer configuration of CeO2 and ZrO2 ensure enhanced protection of the steel in comparison to the single CeO2 coatings and uncoated steel. The surface morphology and anticorrosion properties depend significantly on the treatment temperature of both CeO2 underlayer and ZrO2 top layer. At lower treatment temperatures, they are relatively dense and smooth. The corrosion resistance of the multilayers slows down, when ZrO2 coatings were heated above 500oC. This probably is due to the more pronounced crystallization of cubic zirconium dioxide, resulting in deeper boundaries between the individual grains. The protective properties of a CeO2/ZrO2 multilayers could be attributed to the low crystallized structure with very fine crystallites.

Thin films deposited on glass substrates by sol-gel containing ZrO2 show photocatalytic activity, which are compared with TiO2 – which is used as a standard photocatalytic material applied in photovoltaics. By modifying ZrO2, coatings on glass surfaces were obtained, which are characterized by high properties, which are a prerequisite for use in photovoltaics. The coatings are dense and nanocrystal line according to SEM and XRD studies and optically transparent according to UV-VIS-NIR spectra

The paper focuses on the degradation of molds that are used for the technology of high-pressure casting of Al and its alloys. The method of high-pressure casting of aluminum products is one of the widely used production methods, which at the same time meets the requirements for precision and productivity in the production of cars and various mechanical parts. In the high-pressure casting process, the molds are exposed to various thermal and mechanical loads, where the molds and their shaped parts are degraded. The paper presents the results of research focused on the use of duplex PVD coatings to increase the life of shaped parts of molds for high-pressure casting of Al and its alloys.

Physicomechanical and adhesion characteristics, specific surface energy of vacuum coatings formed on high-speed steels of the P6M5 type subjected to processing at cryogenic temperatures are investigated. The structural transformations occurring in vacuum coatings formed on steel substrates with subsequent processing at low temperatures were studied. A change in the tribological characteristics of titanium nitride coatings during subsequent processing in a cryogenic liquid is shown.

Compositions of the products of the electrolysis of melts based on a eutectic mixture of sodium chloride–lithium fluoride and sodium tungstate, which contains molybdenum (VI) and tungsten (VI) oxides, molybdates, tungstates, and carbonates of lithium or sodium, are investigated. It is shown that, depending on the content of melt components, the products of electrolysis are carbon, molybdenum, tungsten, and their bronzes and carbides. The conditions of the deposition of galvanic coatings of molybdenum and tungsten carbides on carbon, nickel, and copper matrices are determined.

When it comes to space vehicles for humans (as the International Space Station), the most important goal is how to achieve safety in the space vehicles, that people should survive their travel to space and return safely, in good health. In this connection, the primary role of the space materials science is to ensure the long-term trouble-free operation of materials and elements of equipment in a space environment. In this paper we present the second part of the brief analysis of some different aspects of the space environment and their effect on the properties of materials which are located or are mounted on the body of the International Space Station.