INCREASING THE DURABILITY OF DETAILS TO WORK UNDER REPEATABLE LOADS

The article presents the results of the development of processes to improve the performance of parts operating under repeated variable loads, taking into account the reasonable parameters of surface plastic deformation (SPD) and cold gas-dynamic spraying of coatings. The influence on the parameters of the working surface layer, the nature of the distribution of the stress-strain state of the surface layer of material and residual compressive stresses, as well as the values of the used resource of plasticity of the surface layer of the workpiece, the parameters of the SPD process. The article shows that the main factor in the formation of residual compressive stresses during SPD is the decrease in the density of the surface layer of the workpiece, which is associated with the use of the plasticity resource. The model of calculation of the used resource of plasticity of material of preparation at SPD which allows to provide the improved quality of a surface layer of details is offered. A method of moving the workpiece layers with maximum hardening and residual compression stresses to the surface of the part by applying a deforming tool of reduced size in the following passes with coating the surface of the part with gas-dynamic spraying before SPD. Cold gas-dynamic coating by spraying, in contrast to most known gas-thermal coating methods that take place under significant temperature effects on the surface of the part, which is unacceptable for surfaces treated by SPD methods, provides a permissible temperature regime for creating special auxiliary coatings while preserving surface properties SPD. The technology of gas-dynamic coating by spraying includes heating the compressed gas (air), directing it into the nozzle and forming in this nozzle supersonic air-powder flow, sprayed material (copper, aluminum), acceleration of this powder material to supersonic speeds and directing it to the surface of the processed product. As a result, a special auxiliary coating (copper or aluminum) is formed on the surface of the product, which improves the parameters of the SPD process.

INCREASING OF THE DURABILITY OF DETAILS WORKING UNDER REPEATABLE- LOADS

The article develops processes of increase the durability of parts operating under repeated loads, by justifying the parameters of surface plastic deformation (SPD) and cold gas-dynamic coating. The influence on the depth of the reinforced surface layer, the nature of the distribution of the stress-strain state of the material and residual compressive stresses, as well as the value of the used plasticity of the metal, the parameters of the SPD process. The hypothesis is substantiated that the main factor in the formation of residual compressive stresses during SPD is the decrease in metal density, which is associated with the use of the plasticity resource. The model of definition of the used resource of plasticity of metals at SPD is developed, that allows to provide qualitative characteristics of a surface layer of details. Methods for shifting the layer with maximum hardening and residual compressive stresses to the surface of the part by using a deformable tool of smaller dimensions in subsequent passes and gas-dynamic coating before SPD. The vast majority of traditional gas-thermal coating methods occur at significant temperature effects on the surface of the part, which is unacceptable for the surface treated by SPD methods. Cold gas-dynamic spraying provides an allowable temperature regime for the creation of special auxiliary coatings while maintaining the properties of the surface treated by SPD methods. The technology of gas-dynamic coating includes heating the compressed gas (air), feeding it into the nozzle and forming a supersonic air stream in this nozzle, introducing a powder material into this stream, accelerating this material in the nozzle by a supersonic air flow and directing it to the surface of the workpiece. As a result, a special auxiliary coating is formed on the surface of the product, which provides optimal parameters of the SPD process.

Serum N-Glycosylation in Parkinson’s Disease: A Novel Approach for Potential Alterations

In this study, we present the application of a novel capillary electrophoresis (CE) method in combination with label-free quantitation and support vector machine-based feature selection (support vector machine-estimated recursive feature elimination or SVM-RFE) to identify potential glycan alterations in Parkinson’s disease. Specific focus was placed on the use of neutral coated capillaries, by a dynamic capillary coating strategy, to ensure stable and repeatable separations without the need of non-mass spectrometry (MS) friendly additives within the separation electrolyte. The developed online dynamic coating strategy was applied to identify serum N-glycosylation by CE-MS/MS in combination with exoglycosidase sequencing. The annotated structures were quantified in 15 controls and 15 Parkinson’s disease patients by label-free quantitation. Lower sialylation and increased fucosylation were found in Parkinson’s disease patients on tri-antennary glycans with 2 and 3 terminal sialic acids. The set of potential glycan alterations was narrowed by a recursive feature elimination algorithm resulting in the efficient classification of male patients.

Study the possibility of forming multifunctional coatings of gas-dynamic coating

The article considers the progressive gas-dynamic method of forming multifunctional coatings. This method has considerable advantage over other methods of deposition and can be used with success to improve the operational characteristics of the components and mechanisms of technological equipment. The optimal size of the spray copper and aluminum particles, as well as the necessary speed. The basic stages of formation of the coating by this method. The review of modern equipment for gas-dynamic spraying.