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The effect of various binding agents based on aqueous solutions of nitric acid, yttrium nitrate and orthophosphoric acid and yttrium hydroxide gel on the physical and mechanical properties of casting molds based on Y2O3 has been studied. It is shown that the most promising binding agent for yttrium oxide casting molds is a phosphate bond. The data describing the curing mechanism of phosphate-bonded molding mass is presented. The influence of the concentration of binding agent solutions on the strength characteristics of molding materials after curing and heat treatment is shown. Information about the interaction of yttrium oxide powder molds with phosphate-binding with titanium melt of VT1-0 and VT6 grades is presented. The obtained data allowed us to describe the advantages and disadvantages of the developed molding compound. A method for producing casting molds based on yttrium oxide powder with a yttrium phosphate-binding agent was developed based on this research.

The article presents the results of a study of the influence of inertia forces on the adhesion of a coating to the outer surface of bodies of revolution during thermal spraying. A mathematical apparatus is proposed for calculating the inertia forces acting on a coating particle when rotation bodies are applied to the outer surface. As a result, dependences are revealed that make it possible to predict the adhesion strength of the coating to the steel base during thermal spraying.

Titanium carbonitride (TiCN) is of high relevance in the field of creating wear-resistant protective coatings in order to ensure maximum wear resistance and service life of parts of friction units. Titanium carbonitride coatings were obtained by magnetron sputtering at various bias substrate in the range from 0 to -130 V with a step of 10 V. The effect of the bias substrate on the deposition rate, phase and elemental composition, and the friction coefficient of the obtained coatings was investigated. As a result of the obtained dependences, the most optimal mode of deposition by the method of reactive magnetron sputtering with a negative bias voltage on the substrate was determined.

The operation of the hydraulic hammer is affected by a random or targeted change in certain parameters of the hydraulic drive, which has to be taken into account as early as at the design stage of its subsystems in order to find an optimal system performance. One of such parameters is the inertia of the power fluid. Being formed in the transitional periods, the inertial forces have a significant impact on the basic parameters of the movement of the hydraulic hammer piston as well as on the dynamics of the power impulse hydraulic system. The dynamics of the hydraulic hammer piston during the reverse stroke is considered in the article. Based on mathematical modeling, the time to fill up the work chamber of the hydraulic cylinder of the hammer is determined. The relationship between the power fluid inertial component and the full working stroke travel time of the piston.