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The results of investigation of the thickness and microhardness of electrospark coatings (ESCs) of amorphous and nanocrystalline alloys (NCAs) are presented. It is shown that the application of amorphous and NCAs as electrode materials increases the thickness of ESCs and the produced coatings are characterized by high hardness.

Determination of the real technical condition of mechanical transmissions is a key problem of diagnosing in the course of maintenance and repair of transport and technological machines in operation. The most reliable method of determining the technical condition of mechanical transmission assemblies taking into account the prospect of digitalization is thermal diagnostics based on the change in the intensity of infrared radiation of the heat source under normal conditions and under pre-failure condition. The aim of the research is practical testing of the method of thermal diagnostics based on the development of the analytical model of thermal stress and simulation of temperature loads by the method of finite-element analysis taking into account the resource bench tests on the example of the joints of drive lines. Research object -the cardan joint as per GOST R 52923-2008 (type 3 row IV, bearings 804707K4S10). The method of research includes: analytical study of cardan joint heat generation at three hierarchical levels of elementary joint "crosspin-bearing", crosspiece assembly and cardan joint assembly taking into account heat generation of adjacent parts and assemblies; simulation technique of stress-strain state taking into account thermal loading of parts on the basis of 3D-model of the joint using CAD-technology COMPAS 3D and CAE-technology APM FEM; comparative analysis of analytical and simulation technique results on the basis of data of resource bench tests on dynamics of radial play in the joint and temperature of bearing units at the level of extreme operational loading modes. As a result of the studies, the adequacy of the analytical mathematical model of the thermal stress of the cardan joint was confirmed, the method of simulation technique was verified and the operability of the complex method of thermal diagnostics for determining the real technical condition of mechanical transmission units was evaluated.

In most industrialized countries fixed assets dominate in the structure of national wealth. As elements of fixed assets, the authors of this article consider industrial and non-industrial buildings as part of enterprises of the agroindustrial complex. The study of the effectiveness of building restoration shows that the criteria for effective repair and reconstruction of a building are the maximum reduction in physical wear and minimum capital investments. Based on the analysis of defects in building structures found during the determination of the technical condition of buildings of enterprises of the agroindustrial sector, the article formulates the classification of the most frequent defects that reduce the performance properties of fixed assets of enterprises and sets the mathematical dependence of the physical deterioration of fixed assets from the period of their operation correlation regression equation. Based on the carried-out modelling of the intensity of wear, a system for monitoring the technical condition of buildings based on the so-called "controlled operation" of buildings is proposed in order to effectively use depreciation charges to eliminate physical deterioration of buildings. Based on the results of the study of methods for calculating depreciation and regulatory documents governing the respective service life of buildings, a method was developed to optimize the planning of capital investments to eliminate the physical deterioration of the enterprise's buildings as elements of fixed assets. The application of the developed method allows to increase the efficiency of management decision-making by the management of the enterprise, which has an impact on the effectiveness of the finished product output by enterprises of the agroindustrial complex.

The results of investigations of the hardness and wear resistance of the working sections of machines, hardened using cermet materials in the form of paste, are presented. The optimum composition of the paste which greatly increases the service life of the working sections of the machines is determined.In the cultivation and the service of machines, the working sections are subjected to rapid wear as a result of the effect of abrasive particles, the cutting surfaces are blunted, and the shape, profile and working dimensions are greatly changed. Consequently, the quality of field operations is disrupted, the performance of these operations is delayed, the idle time of equipment is extended, the consumption of fuel and lubrication materials is increased and the amount of finished products is decreased [1 -3]. Therefore, the development and application of technologies capable of increasing the wear resistance of the working sections of machines is an important task and the solution of this task is of considerable importance in many areas of production.At present, a promising hardening method, which greatly increases the hardness and wear resistance of the cutting edges of the working sections of the machines, is vibroarc hardening (VAH) with cermet materials [4 -6]. In VAH, a cermet material in the form of paste is deposited on the hardened surface of the working section and burning of the direct arc results in both thermal diffusion hardening of the surface with alloying elements, including the composition of the cermet material, and VAH of the cermet coatings. A distinguishing feature of VAH is the absence of any significant heat input into the component during hardening.The cermet material developed in this study consists of a steel matrix (surfacing powder) with inclusions of alumina Al 2 O 3 , silicon SiO 3 , boron carbide B 4 C, refined to the nanosized state, and also alloying elements: nitrogen, present in the ammonium nitrate NH 4 NO 3 , and aluminium [5 -7]. Aluminium is used for deoxidation of iron and also for the formation of the ceramic phase by transformation to the aluminium oxide Al 2 O 3 and, in subsequent melting, to corundum. Corundum occupies position 9 in the mineralogical table of hardness, which is very close to the hardness of diamond. The matrix is an impact resistant, sustaining and composite frame of the cermet material. Therefore, the matrix material is produced from steelsurfacing powders with high hardness and abrasive resistance, for example PG-10N-01, PR-N70Kh17S3R4 and PG-SR4. To ensure the high impact toughness of the hardened surfaces, the content of the matrix material in the composition of the cermet material should not be less than 50%.Preliminary investigation showed that each of the components of the cermet material has a strong effect on the efficiency of hardening of the working sections of the machines. Therefore, investigations were carried out to determine the effect of the components of the cermet material on the hardness and wear resistance of hardened surfaces in orde...

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Today, the use of aerodynamic dryers for drying various types of fruit crops is very current. In them, the electric energy spent on the drive of the centrifugal fan is transformed into thermal energy due to the mutual friction of the air flows circulating in the closed chamber. In order to increase the energy efficiency of the drying process, the heat of the waste drying agent was used in the research. The presented dryer was equipped with a combined heat exchanger. In order to predict the thermal performance of the combined heat exchanger depending on external factor variables, the dependence of the temperature of the fresh drying agent at the outlet of the combined heat exchanger on the dryer operation time is theoretically determined on the basis of the heat balance equation. The air solar collector in the combined heat exchanger made it possible to increase the temperature of the drying agent at the outlet by another 10oC without extra costs of electrical energy. A comparative analysis of the results of experimental and theoretical studies showed their high convergence.

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