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.

In the present work, the titanium carbonitride coatings were deposited by the reactive magnetron sputtering method at different substrate bias: 0, −70 V, and −100 V. The effect of the substrate bias on the structure, composition, and mechanical and tribological properties of titanium carbonitride coatings was studied. Scanning electron microscopy, nanoindentation, sliding wear test (ball-on-disk method), X-ray phase, and elemental analysis methods were used to evaluate the tribological properties and microstructure of the thin coatings. The dependencies obtained resulted in the determination of the most preferred mode of deposition by magnetron sputtering at a negative substrate bias in an atmosphere of argon–acetylene–nitrogen.

The micro-arc oxidation (MAO) technique was employed to produce calcium phosphate coatings on titanium surfaces using an electrolyte composed of hydroxyapatite and calcium carbonate in an aqueous solution of orthophosphoric acid. The coatings’ morphology and composition were regulated by adjusting electrical parameters, specifically the duty cycle and voltage. This study examined the effects of the duty cycle and voltage during the MAO process on the microstructure and composition of calcium phosphate coatings on VT1–0 titanium substrates. Scanning electron microscopy (SEM) was utilized to analyze the microstructure and thickness of the coatings, while X-ray diffraction (XRD) was employed to determine their phase composition. The findings reveal that the surface morphology of the calcium phosphate coatings transitions from a porous, sponge-like structure to flower-like formations as the duty cycle and voltage increase. A linear increase in the voltage within the applied duty cycles led to a rise in the size of the forming particles of amorphous/crystalline structures containing phases of monetite (CaPO₃(OH)), monocalcium phosphate monohydrate (Ca(H₂PO₄)₂·H₂O), and calcium pyrophosphate (γ–Ca₂P₂O₇).

The article describes the results of experimental studies for the effect of thermal treatment (TTM) of G-X300CrMo27-1 high-chromium cast iron samples in the solid–liquid and liquid state on the structure, phase composition, and properties of ingots. For ingots with a carbon content of 2.8 to 4.5 wt%, cooled at a rate of 3.3 * 10⁻² deg s⁻¹, the dependencies of the structure, phase composition, composition of primary, eutectic carbides and matrix, hardness HV and microhardness of its individual phases and resistance to abrasive wear from the temperature of isothermal holding at TTM. A significant effect of the TTM temperature of melts on the structure and properties of high-chromium cast iron ingots was detected. The temperatures of inflection on the plotted curves for the characteristics of the structure and properties of the ingots were associated with a phase transition in iron at 1400 °C and with a point on the phase diagram liquidus of the Fe-Cr system. This as well as an increase in the concentration of chromium in the composition of primary carbides with an increase in the TTM temperature up to 1480 °C, made it possible to assume that (Cr, Fe)₇C₃ clusters stable in composition were formed in the melt of such cast irons below ∼1500 °C. The reasons for the decrease in the size of primary carbides during G-X300CrMo27-1 molten chromium iron overheating above 1500 °C were substantiated based on these data. During the TTM of fine-crystalline ingots made of hypereutectic cast iron in the temperature range between the liquidus and solidus lines, it was detected that the primary carbides (Cr, Fe)₇C₃ recrystallized resulting in a significant decrease in the chromium content and an increase in the iron content in them. At the same time, their sizes did not change significantly. Their share increased, and the share of eutectic carbides decreased. Such a process also had a significant impact on the properties of the resulting ingots. The most preferable temperatures of hot metal cast irons in the liquid and solid–liquid states were identified based on the results of the studies.

The possibility of using microsilica in the production of mullite–silica refractories was assessed. The chemical and mineralogical compositions of the raw materials, refractory Arkalyk clay and microsilica, were studied. It has been found that primary mullite and quartz formation occurs due to dehydration of kaolinite with the formation of intermediate metakaolinite. The introduction of alumina and microsilica into the charge composition promotes the formation of secondary mullite due to the interaction of aluminum oxide and highly dispersed chemically active microsilica. Free silica in compositions undergoes polymorphic transformations with the formation of cristobalite and tridymite. Mullite–silica refractories with an open porosity of 21%, a compressive strength of 42 MPa, and a thermal deformation temperature under the load of 0.2 MPa–1350 °C were obtained.

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.