Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
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Blednova Zhesfina Mikhailovna

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professor

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Kuban State Technological University
   

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Articles count: 10

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10811 kb

FORMATION OF SURFACE LAYERS OF NANOSTRUCTURED TINICO, STIMULATED WITH MECHANICAL ACTIVATION

abstract 1021408056 issue 102 pp. 881 – 898 31.10.2014 ru 235
This article presents a complex method of formation of the surface-modified layers of materials with shape memory effect, including high-speed flame spraying powders TiNiCo with a cobalt content of 2 and 5%, subsequent thermal and thermomechanical treatment, allowed forming nanostructured surface layers with a high level of functional and operational properties. It is shown that the TiNiCo complex processing layer allowed reducing the porosity of coatings and increasing the strength of adhesion of the coating to the substrate. Surface modification TiNiCo for optimal regimes allowed increasing fatigue life under high cycle loading by 30-40% and wearing 3-3.5 times. Based on comprehensive research metallophysical surface layers obtained new information on the nanoscale composition
13714 kb

INFLUENCE OF PARTICLE SIZE DISTRIBUTION, ENERGY CONDITION AND REACTIVITY OF THE SPRAYED MATERIAL ON THE FORMATION OF SURFACE LAYERS NANOSTATE MADE OF SHAPE MEMORY MATERIALS (SME)

abstract 1211607021 issue 121 pp. 484 – 498 30.09.2016 ru 92
The article contains a block diagram of the mechanical activation process of multicomponent shape memory materials, taking into account the variety of influencing factors. We have proposed to evaluate the reactivity of the sprayed material using the energy criterion (energy intensity), determined by the additivity concept as an energy amount of the raw material and energy accumulated during mechanical activation. Power consumption of the raw material depends on the chemical and phase composition and is determined based on the similarity between the melting energy, plastic deformation and fracture on the thermodynamic characteristics and diagrams of the systems. The energy stored in the MA is determined on the basis of X-ray structural analysis. We have demonstrated that with increasing of grinding precision there is growth in the number of active centers, which enables nanostructurization of surface layers in high-velocity oxygen-fuel spraying (HVOF). According to the study, we have developed practical recommendations for effective implementation of mechanical activation of the shape memory material
781 kb

MECHANICAL GRINDING OF SOLID POWDER MATERIALS

abstract 1121508057 issue 112 pp. 761 – 773 30.10.2015 ru 857
The article is dedicated to the determination of conditions for solid bodies’ fragmentation, providing minimal size of particles by means of their mechanical dispersion through the example of powders of titanium carbide (TiC), cubic boron nitride – borazon (CBN) and boron carbide (B4C). The theoretical and practical aspects of the process of mechanical fragmentation of particles of solid powder materials in ball mill for their further utilization in furnace charge for high-speed gas-flame sputtering of wear-resistant composite materials are examined in the article. Methods of preliminary calculation of minimum allowable size of solid particles of powder materials during mechanical fragmentation, based upon Griffiths’ mechanical theory of rapture using experimental data for hardness of material and its yield are proposed and theoretically substantiated. There we have the results of experiments on mechanical fragmentation of titanium carbide in attritor, boron carbide and cubic boron nitride in centrifugal planetary mill, confirming correctness of theoretical propositions and calculations are set out. Recommendations on mechanical fragmentation of solid powder materials in ball mills are formulated as well
257 kb

METHOD OF CALCULATION OF THE RESISTANCE MOMENT OF ROTATION OF THE TRACK MODULE ON THE RUBBER- REINFORCED TRACK

abstract 1602006003 issue 160 pp. 30 – 38 30.06.2020 ru 5
In modern combine building over the past few years, there has been a trend towards increasing the productivity of machines and, as a consequence, their physical weight. However, as the weight of the combine harvester increases, the necessary condition for its movement in the field in the course of work is to meet the requirements for its support area. As a result, manufacturers have to increase the size and number of wheels of the machine. One solution to this problem is to replace the wheelset of agricultural machines with replaceable rubber track modules. In this case, the very principle of calculation of the main technical characteristics of the engine changes, and if we are talking about the drive axles of agricultural machinery, the calculation methods can be roughly approximated to the calculation of tracked machines with metal tracks. However, in the case of driven axles, there is an intersection in the calculation methods between the classic calculation of the wheel chassis and the calculation of the tracked chassis. The problem is that the tracked chassis are not usually guided like the wheels, so the calculation methods need to be refined by introducing new evaluation criteria because of new power factors in the track module. The article proposes an alternative calculation model to calculate the maximum resistance torque of a track module on a rubber track
1128 kb

RESEARCH OF RESISTANCE OF PRODUCTS WITH COMPOSITE COATINGS LAYER FROM MATERIALS WITH SHAPE MEMORY EFFECT TO ABRASIVE WEAR

abstract 1281704041 issue 128 pp. 558 – 574 28.04.2017 ru 143
The article gives results of research of the process of abrasive wear of samples made of Steel 45, U10 and with applied composite surface layer "nickelmulticomponent material with shape memory effect (SME) based on TiNi". For the tests we have chosen TiNiZr, which is in the martensite state and TiNiHfCu, which is in the austenitic state at the test temperature. The formation of the surface layer was carried out by high-speed gas-flame deposition in a protective atmosphere of argon. In the wear test, Al2O3 corundum powder was used as an abrasive. It is shown that the wear rate of samples with a composite surface layer of multicomponent materials with an SME is significantly reduced in comparison with the base, which is explained by reversible phase transformations of the surface layer with an SME. After carrying out the additional surface plastic deformation operation (SPD), the resistance of the laminated composition to abrasion wear is greatly enhanced, due to the reinforcing effect of the SPD. It is recommended for products working in conditions of abrasive wear and high temperatures to use the complex technology of formation of the surface composition "steel-nickel-material with high-temperature EPF", including preparation of the surface of the substrate and the deposited material, VGN in the protective atmosphere of argon, followed by SPD
11263 kb

SIMULATION OF THE TEMPERATURE FIELD DURING LASER MELTING OF MATERIAL WITH A SHAPE MEMORY BASED ON TiNi

abstract 1071503058 issue 107 pp. 858 – 876 31.03.2015 ru 274
A thermal physical and mathematical model of laser cladding with TiNi on steel was developed which allows us to monitor the formation of the structure and the properties of the surface layer. A description of the model included assumptions and simplifications; analysis of the energy balance; numerical modeling of thermal processes; evaluation of the temperature distribution; experimental verification of the obtained solutions. The composition of the steel and TiNi alloy was examined as a two-layer material with different thermal characteristics. The energy balance of the system was described with a heat equation in a three-dimensional form. The main channels of the radiation energy costs were taken into account: absorption surface of the product, loss owed to the reflection surface, energy absorbed by the coating which did not come down to the base material. To solve the differential equation of heat conduction we used the Fourier integral method. In assessing the temperature distribution we have reviewed a dimensional problem when exposed to a point source of the Gaussian distribution in a pulsed mode. Computer calculations used MathCAD graphs of temperature changes at different depths of the TiNi layer and the steel substrate. The results obtained allowed us to develop the recommendations for optimizing the technological parameters of laser cladding of TiNi. The simulation of thermal processes significantly reduces the time and resources required to develop the technology, allowing prediction of the quality of the surface layer during the development of the technology and promoting the adoption of efficient technical and technological solutions
746 kb

STRUCTURE EVOLUTION OF MULTIPHASE POWDER SME MATERIALS AT VARIOUS STAGES OF THE PROCESS OF MECHANICAL ACTIVATION

abstract 1321708097 issue 132 pp. 1217 – 1230 31.10.2017 ru 77
The mechanical activation allows creating a active state in a solid, opening the prospect for holding and accelerating the chemical reactions between solids and getting materials in a nonequilibrium state. As a result of mechanical activation of the powder compositions of the active phase transformations occur in them, which lead to the formation of solid solutions and various intermediate connections, providing dispersion and dispersion hardening of materials included in the composition. The results of the study of the granulometric composition, the phase transformations and structure evolution in multiphase materials with SME Ni-30%at.Ti-20%at.Hf and Ni-33%at.Ti- 18%at.Zr at different stages of the process of mechanical activation carried out in planetary ball mill the centrifugal type is represented in the article. During mechanical activation, a composite mix is assimilated by the particles of processed material input of mechanical energy in the form of new interfaces, defects of the crystal lattice. At collision of particles and grinding bodies in contact high local temperature and pressure occur, which in some cases can lead to melting of the most fusible components. When a local increase in temperature between the particles of titanium, hafnium, zirconium and carbon solid-phase reactions become possible due to diffusion of atoms of one component into the crystal lattice of the other. Experimental studies have shown that the use of mechanical activation allows creating an effective technology of preparation of the starting material for high-speed flame spraying
3353 kb

TECHNOLOGICAL RULES OF FORMATION OF STEEL – NANO-STRUCTURED LAYER TI-NI-CU COMPOSITION WITH A HIGH SPEED FLAME SPRAYING

abstract 1021408007 issue 102 pp. 156 – 173 31.10.2014 ru 581
The combined method of formation of the “Steel - superficial of materials with effect of memory of the form on the basis of TiNiCu” composition, which includes mechanical activation of powder, the high-speed gas-flame dusting, the subsequent thermo-mechanical processing is considered. The operating parameters are defined and the optimum modes of processing providing formation of the layers with nano-sized structure are recommended, chemical and phase composition of which corresponds to the shape memory effect
1405 kb

THE EFFECT OF HIGH FLAME SPRAYING MECHANICALLY ACTIVATED POWDERS OF Ti-Ni-Ta ON STRUCTURAL-PHASE STATE AND THE FUNCTIONAL AND THE MECHANICAL PROPERTIES OF SURFACE LAYERS

abstract 1071503044 issue 107 pp. 632 – 642 31.03.2015 ru 533
Based on the analysis of the phase composition, the average grain size measured by high resolution electron microscopy and multifractal parameterization structure shows the relationship of coating properties with their structural-phase state. The regularities of the evolution of the structural parameters and multifractal characteristics of the surface layers of materials with shape memory can predict the properties of the composition of the "steel-coating". On the basis of experimental studies, it has been shown that mechanical activation of powders of materials with shape memory effect based on TiNiTa makes it possible to create an effective technology training sprayed material which will generate nano-structured surface layers by high-speed flame spraying. The influence of the mechanical activation of TiNiTa powder on the quality of surface layers formed by high-speed flame spraying was investigated, and a significant improvement in the structure of the surface layer was found, with reduced porosity, high adhesion, and, consequently, increased functionality and mechanical properties. The evolution of the structure at all stages of surface modification based on the fractal approach multifractal parameterization method, which is based on qualitative analysis and instrumental methods in addition to classic microstructure parameters like grain size and specific area related to the physical and mechanical properties, is quantitative information. It was established experimentally that after high-speed flame spraying, the performance characteristics of mechanically activated shape memory TiNiTa powder improved: cyclic durability under high-cycle fatigue increased by about 35.6%, and the wear resistance increased by 3.6 times
3529 kb

ZIRCONIUM EFFECT ON THE STRUCTURE AND PROPERTIES OF TINI BASED ALLOY

abstract 1211607020 issue 121 pp. 475 – 483 30.09.2016 ru 241
We have performed a mechanical activation of TiNi powder; as a result, PN47T26TS27 powder after mechanical activation is flat discs ranging in size from 10 to 30 microns. We have developed a composition technology "steel - material with shape memory effect" by high-velocity oxygen-fuel spraying of mechanically activated powder based on TiNi. We have determined the optimal processing parameters to ensure a nanostructured surface layer. We have estimated the process parameters of highvelocity oxygen-fuel spraying. The basic parameters are: propane flow rate 60-85 l / min, that of oxygen 120-160 l / min, flow rate of powder and carrier gas (argon), distance and angle of deposition, and movement speed of the torch, the rotation speed of the coated workpieces. We have carried out macroand microanalysis of surface layers of Ti-Ni based alloy, obtained on proven technology. We have studied the effect of TiNi doping with a third component Zr. The simulation allows us to predict the possibility of using surface modification of products with SME material TiNiZr under certain conditions of temperature and to determine the desired composition of the coating, which provides a positive effect. We have made tests on steel 45 with a surface-modified layer TiNiZr under dry friction conditions, during which there is a significant increase in temperature, we have confirmed the effect of improving the wear resistance
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