Coatings based on titanium carbonitride alloyed with zirconium and chromium were deposited using the method of reactive magnetron sputtering on the surface of titanium VT1–0. The effect of alloying titanium carbonitride with zirconium and chromium on the tribo- and corrosion properties of the coating has been studied. Coatings with different compositions were formed by changing the ratio of alloying elements to titanium in a single target. To study the obtained coatings, a scanning electron microscopy, nanoindentation, sliding wear test (ball on disk method), and corrosion tests in 0.5 M Na₂SO₄ and 30% NaCl solution were used. As a result of wear and corrosion tests, friction coefficients, mass index, and corrosion rate of alloyed and pure titanium carbonitride coatings were obtained. The average coefficient of friction of the coatings varied in the range of 0.17–0.31. The values of nanohardness are determined depending on the composition of the coatings. From corrosion data, it is determined that TiCrCN and TiZrCN coatings exhibit better corrosion properties compared to TiCN coatings. As a result of the dependences obtained, the preferred composition of the coating, the most resistant to wear and corrosion damage, was revealed.

The development of promising biocompatible composites based on hydroxyapatite with a metallic component is of great interest to researchers. This article describes the synthesis of hydroxyapatite powder by the hydrolytic method and presents the results of mechanical grinding of hydroxyapatite powder. Additionally, in order to study the interaction between titanium and hydroxyapatite powders, the results of their thermal treatment in the temperature range of 600–900 °C are presented. As a result of the hydrolytic method, a powder consisting of Ca₅(PO₄)₃(OH) and CaO phases with a fraction of 400–600 μm was obtained. According to the results of mechanical grinding, it was determined that with an increase in grinding time from 30 to 120 min, the intensive main diffraction lines corresponding to hydroxyapatite decrease. During the thermal treatment of titanium and hydroxyapatite powders, titanium oxidizes forming suboxides and titanium dioxide (TiO₂). At higher temperatures, the hydroxyapatite phase disappears from the mixture, and titanium oxide, calcium phosphate compound, and small amounts of calcium titanate and titanium hydrophosphate are present.

The article presents experimental data on the changes in the structural parameters and properties of castings from high-chromium cast iron G-X300CrMo27-1 depending on the carbon content, which ranged from 2.8 to 4.5 wt. %. Castings were obtained under cooling conditions with two cooling rates—0.083–0.117 °C/s and 4.67–5 °C/s. Changes in the structure and properties of these castings after destabilizing annealing and subcritical heat treatment were assessed. Changes in carbon concentration and cooling rate in the crystallization interval have a significant effect on the sizes of primary carbides (Cr, Fe)₇C₃, and on the fraction of eutectic carbides. The microprobe analysis results indicating the effects of cooling rate on the composition of phases in cast iron castings with carbon contents of 4.2 wt. % are presented. The offset value of the crystallization onset temperature and eutectic point with an increase in the cast iron melt cooling rate from 0.083 to 0.83 °C/s is shown. The changes found in the properties of castings with increases in carbon concentration and cooling rate cannot be unambiguously explained by the transformation of the structure of primary and eutectic carbides and changes in the elemental composition of phases. The composition and condition of the matrix has a significant effect on the hardness, bending strength and abrasion resistance of castings. It is suggested that internal stresses arising in primary and eutectic carbides affect the properties of castings in the cast and heat-treated state.

Metal parts in machinery often fail as a result of damage caused by wear and tear, resulting in the loss of functionality of the products. Thin film solid nitride coatings are used to improve the wear resistance and service life of parts and are considered to be effective. The article presents a brief overview of modern literature in the field of obtaining wear resistant coatings of titanium carbonitride by using magnetron sputtering. The review presents a detailed assessment of the scientific results obtained depending on the deposition parameters and the conditions for obtaining coatings. The results of the coefficient of friction, wear rate of the coating and counterbody, nanohardness and adhesion force of coatings obtained by magnetron sputtering and its modifications are shown. The influence of alloying elements on the mechanical and tribological properties of titanium carbonitride coatings is considered. Recent advances in the production of titanium carbonitride coatings with improved wear characteristics are discussed.

The work is devoted to the problem of an increase in the proportion of scrap metal in castings smelted and produced from wear-resistant chromium cast irons. Castings obtained with more than 60% of armor scrap and cracked during solidification and subsequent heat treatment were selected as research objects. Castings of similar mill armor after operation characterized with different wear resistance were selected to compare the characteristics of the structure and properties. The composition, structure, amount of non-metallic inclusion and porosity of samples cut from identical places of castings were studied with the help of the methods of optical and scanning microscopy, metallographic analysis, X-ray fluorescence analysis, and measurement of Vickers hardness. The characteristic localization of non-metallic inclusions of various types in the structure of cast iron samples was considered. An increase in the proportion of non-metallic inclusions in cast irons obtained using a high proportion of scrap was found, and it was shown that non-metallic oxide inclusions with a loose structure had the most negative effect. Along with porosity and primary crystals of carbide (CrFe)3Ctheydo not prevent the propagation of cracks caused by internal stresses arising during crystallization and subsequent polymorphic transformations in castings.

This study presents the results of a study of the reaction interaction and contact angle during contact between a titanium melt and a calcium metatitanate substrate. It is shown that at temperatures slightly above the melting point, the titanium melt poorly wets the CaTiO₃ substrate surface. The contact angle and the onset temperature of active reaction vary depending on the fractional composition of the CaTiO₃ powders from which the substrates are made and their porosity. Under isothermal holding conditions below the onset temperature of active reaction, the contact angle changes insignificantly. At the onset temperature of the reaction interaction, after a short stabilization period of the contact angle, the reaction leads to rapid penetration of the molten droplet into the depth of the CaTiO₃ substrate and, in some cases, to the expulsion of a Ca-Ti-O liquid phase from the reaction zone. The interaction of titanium melt with calcium titanate is accompanied by a series of physicochemical reactions associated with the reaction interaction, which intensifies with increasing temperature and causes the restoration of calcium to a metallic state and the dissolution of oxygen in the titanium melt, as well as the formation of a liquid Ca-Ti-O layer in the transition zone.