The article investigates changes in the characteristics of the surface layers of parts processed by methods of surface plastic deformation (SPD). It is shown that at SPD the strength and hardness characteristics of the material increase and residual compression stresses are formed. On the basis of the study of the stress-strain state of the material at the SPD, its non-monotonicity is established, which is manifested in the gradual change of sign of the components of deformations and stresses. In this regard, a tensor-nonlinear damage accumulation model was used to evaluate the deformability of the material, which takes into account the directional nature of the damage and the anisotropy of the plasticity of the deformed metal. Based on this model, an expression was obtained to determine the plasticity resource used in the case of multi-stage SPD. According to the results of the calculations, it is established that the maximum plasticity resource used in the SPD is at a depth of approximately 0.1 of the diameter of the plastic footprint of the tool, and destruction at full exhaustion of the plasticity resource occurs in the form of peeling of thin plates of appropriate thickness. Recommendations for displacement of the most reinforced layers to the surface of the workpiece are developed, as well as recommendations for limiting deformation by the amount of plasticity resource used. The conducted research allows to assign the optimal modes of SPD at the stage of technological process design. A device for cold gas-dynamic spraying was developed and the possibility of creating antifriction sections using it was investigated. Graphs of dependence of geometrical parameters of the deposited layer on the sputtering distance are constructed and methods and schemes of preparation for deposition of the surface of the workpiece using SPD methods are developed. Experimental cold gas-dynamic spraying was carried out and optimal parameters of the process of spraying of antifriction layers of bronze and metal polymers (pressure, and the temperature of the compressed air and the temperature of the workpiece) on the formed roller surface were determined. A new concept of increasing the contact strength and durability of friction pairs is proposed.

The article presents the results of development and research of the technological process of cold forming rolling of aluminum billets. The main obstacle to the implementation of such processes is the danger of destruction of materials, which necessitated the study of the stress-strain state, plasticity and assessment of the deformability of the workpiece material. To experimentally determine the ductility of metals, a rolling method was developed, according to which the deformation of the free side surface of the cylindrical sample occurs under uniaxial tension. Increasing the degree of deformation and bringing the material to fracture is provided due to the increase in the radii of the rolls during rolling and deformation of the sample on the wedge. Analysis of the stress-strain state of the free side surface of the cylindrical workpiece was performed by the finite element method, which used a specialized engineering software package DEFORM 3D. As a result, a significant inhomogeneity of the stress-strain state in the deformation zone is established. The most severe stress state is observed on the free side surfaces of the workpiece, which causes the danger of its destruction in this area. The dependence between the relative compression of the workpiece during rolling and the intensity of deformation on its side surface is obtained, which allows to determine the limiting thickness of the workpiece before destruction. As a result of the assessment of the deformability of aluminum alloys during cold rolling, using the curves of limit deformations and the scalar criterion of deformation, the limits to the destruction of the intensity of deformation and the limit value of the relative compression of the workpiece. The use of constructed models makes it possible to determine the value of the used plasticity resource at intermediate stages of rolling.

The article presents the results of research on the processes of creating conductive coatings based on copper and aluminum in order to determine the interaction of components on each other during cold gas-dynamic spraying (CGDS) and substantiate the method of introducing an additional component to obtain the desired composite coating. In particular, under conditions when the copper sputtering coefficient is almost zero (at a working air temperature of 300 °C), it is the search for the experimental dependence of the sputtering coefficient on the percentage of copper and aluminum powders in the sprayed mixture, determining their residual content in the coating and then calculating based on these data, the sputtering coefficients of copper and aluminum. The CGDS method obtained samples with composite coatings from mixtures of aluminum and copper powders at different initial mass concentrations of aluminum (from 0 to 100%, in increments of 10%) Other things being equal (air pressure 0,6 MPa, air heating temperature 300 ° C) . The spraying ratio of the mixture and the residual content of the components in the obtained composite coatings were measured. Data on the residual content of the components in the coating allows you to select the composition of the source powder required to obtain a given content of components in the coating. The dependences of the sputtering coefficients of copper and aluminum on the mass content of aluminum in the sprayed mixture are found. At an initial concentration of aluminum less than 66%. the coefficient of copper sputtering is higher than the coefficient of sputtering of aluminum. Both increase monotonically with increasing aluminum concentration until it reaches 61%. At high concentrations of aluminum (more than 66%) the spray coefficients of copper, aluminum and their mixtures coincide. The obtained data on the residual content of the components in the coating allows you to select the composition of the source powder required to obtain a given content of components in the coating. For example, the maximum residual copper content (~ 95%) can be obtained by adding to the source powder 30-40% aluminum. The obtained results confirm the interaction of the components on each other and justify the method of introducing an additional component to obtain a composite coating containing a component that is difficult to spray.

The article presents the results of research of spraying processes of composite electrically conductive coatings using copper C01-11 and aluminum A20-11 powders in order to determine the effect of components on each other in the formation of cold gas-dynamic spraying (CGDS) and the development of recommendations for the introduction of additional component to obtain a composite coating with a given ratio of different components. For example, when at a working air temperature of 300 ° C the copper sputtering coefficient is almost zero, it is a search for the experimental dependence of the sputtering coefficient change depending on the percentage of components of copper and aluminum powders in the sprayed mixture and determination of their residual content in the coating. based on the obtained data of the sputtering coefficients of copper and aluminum. The CGDS method obtained blanks with composite coatings from mixtures of powders of aluminum A20-11 and copper C01-11 at different initial concentrations of aluminum by weight (from 0 to 100% with a step of 10%) under otherwise equal conditions (air pressure 0,6 MPa, temperature air heating 300 ° C). The sputtering coefficient of a mixture of copper and aluminum and the residual content of components in the sprayed composite coatings were found. Data on the residual content of the individual components in the sprayed coating allows to determine the composition of the source powder required for spraying a given content of each of the components in the coating. The dependences of the spraying coefficients of copper C01-11 and aluminum A20-11 on the mass content of aluminum in the sprayed mixture were found. When the initial concentration of aluminum is less than 66%, the coefficient of copper deposition is greater than the coefficient of deposition of aluminum. Both increase with increasing concentration of aluminum until it reaches 61%. At high concentrations of aluminum (more than 66%) the spray coefficients of copper, aluminum and their mixtures coincide. The results obtained on the residual content of the components in the coating allow you to select the composition of the source powder required to obtain the desired content of components in the coating. For example, the maximum residual copper content (~ 95%) can be obtained by adding 30-40% aluminum to the starting powder. The obtained results prove the influence of the components on each other and justify the amount of introduction of an additional component for spraying a composite coating containing a component that is difficult to spray.