This review paper presents a detailed analysis of the influence of high-velocity oxygen–fuel (HVOF) spraying parameters on the microstructure formation and performance characteristics of Cr₃C₂-NiCr coatings. Key HVOF parameters, including the spray distance, oxygen-to-fuel ratio, powder feed rate, and spraying temperature, are examined in relation to their impact on coating properties. Structural parameters such as density, porosity, adhesive strength, and microhardness, which determine the mechanical behavior of the coating, are analyzed. Special attention is paid to wear resistance mechanisms, adhesion to the substrate, and resistance to fatigue failure. Additionally, the thermal stability of the coatings, their coefficient of thermal expansion, and oxidation resistance are investigated. This study also evaluates the morphology and phase composition of the coatings under different HVOF spraying conditions. An overview of modern diagnostic techniques, such as electron microscopy and spectroscopy, is provided. Compared to traditional surface treatment methods, HVOF spraying offers superior coating density, higher adhesion strength, and enhanced wear and corrosion resistance, making it an effective solution for extending the service life of components. Based on the findings, this paper highlights promising applications of Cr₃C₂-NiCr coatings in the aviation, power engineering, and mechanical engineering industries, where high wear resistance and thermal stability are crucial.

The purpose of this study is to determine the possibilities of digital technolo-gies and case study method in the development of creativity of the future teachers in physics teaching through the medium of a foreign language. The Akhmet Yassawi International Kazakh-Turkish University has created computer models of various physical processes and phenomena on the basis of Optics in English training course and has developed a method of their application. Since English opens the way to the formation of creativity, we have evaluated the effectiveness of the methodology we have developed, through the evaluation of creativity. The nearly 73 students were engaged in an experiment presented below in chronological order. The reliability of results obtained at the beginning and at the end of forming stage for each criteria of creativity, as well as for the integral indicator is provided by Pearson criterion . At the beginning of the experiment it is seen that that means there are no differences between the development level of students’ creativity from both experimental and target groups. At the end of the experiment , that means there are significant differences in the development level of students’ creativity.

Quasicrystalline coatings based on Al₆₅Cu₂₀Fe₁₅ are of increasing interest as potential alternatives to conventional wear-resistant materials due to their unique structural and tribological properties. This study explores the influence of air pressure during high-velocity oxy-fuel (HVOF) spraying on the phase composition, morphology, and wear behavior of Al₆₅Cu₂₀Fe₁₅ coatings deposited on U8G tool steel. Coatings were applied at a fixed spraying distance of 350 mm using three air pressures (1.9, 2.1, and 2.3 bar), with constant propane (2.0 bar) and oxygen (2.1 bar) supply. X-ray diffraction analysis identified the formation of Al₇₈Cu₄₈Fe₁₄ and Al_0.5Fe_1.5 phases, while scanning electron microscopy revealed a dense, uniform microstructure with low porosity and homogeneous element distribution across all samples. Tribological testing using the ball-on-disk method showed wear track widths ranging from 853.47 to 952.50 µm, depending on the air pressure applied. These findings demonstrate that fine-tuning the air pressure during HVOF spraying significantly influences the structural characteristics and wear resistance of the resulting quasicrystalline coatings, highlighting their promise for advanced surface engineering applications.

Al-Cu-Fe quasicrystalline coatings were deposited on AISI 321 stainless steel substrates by high-velocity oxy-fuel (HVOF) spraying at oxygen pressures of 3.0, 3.5, and 4.0 bar. The influence of oxygen pressure on the phase composition, microstructure, porosity, corrosion behavior, thermal stability, and microhardness of the coatings was investigated using X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS), ImageJ porosity analysis, electrochemical corrosion testing in 3.5 wt.% NaCl solution, simultaneous thermal analysis (TGA/DSC), and microhardness measurements. XRD analysis revealed the formation of quasicrystalline-related intermetallic phases together with Al, Fe₃Al₁₃, FeAl, Fe₃O₄, CuFe₂O₄, Cu₂O, and CuO phases. The coating deposited at 3.5 bar exhibited the lowest porosity (5.37%), the most homogeneous microstructure, and the largest residual coating thickness after corrosion testing. SEM and EDS analyses indicated that corrosion preferentially initiated at pores, splat boundaries, and phase interfaces, while the coating produced at 3.5 bar demonstrated the most stable surface condition after exposure to a 3.5 wt.% NaCl solution. Thermal analysis showed that all coatings remained stable up to 900 °C. Sample (a) exhibited the lowest mass loss and the highest thermal stability, whereas sample (b) demonstrated the most favorable combination of structural integrity, phase ordering, coating density, corrosion-related performance, and thermal stability. Microhardness values of the coatings ranged from 754 to 778 HV, significantly exceeding that of the AISI 321 substrate. The results demonstrate that oxygen pressure is a critical parameter controlling the microstructure and functional properties of HVOF-sprayed Al-Cu-Fe coatings, with 3.5 bar providing the most balanced set of properties.