International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The main purpose of the study was to assess the usability of a new calculation algorithm for determining the surfactants effective diffusion coefficient. The adsorption of a mixture of non-ionic surfactants onto flat water-air interface was considered. Presented algorithm is composed of a two parts: Ward-Tordai equation solver based on Nyström method for integral equations and golden ratio optimization method used in inverse problem. In the investigation the Langmuir model of an isotherm was assumed. Presented algorithm was successfully used to determine the non-ionic surfactant – Nafol 810D (BRENNTAG) effective diffusion coefficient in the diffusion controlled adsorption process.

Abstract: It was dedicated to solution of scientific and technical problem to increase the level of physical and mechanical and operational properties of the surface of steels by forming strengthened layers diffusion boriding and complex saturation boron and copper in a magnetic field.

In this paper we study the structure, phase composition, microhardness, wear resistance boride coatings obtained on metals and alloys at complex saturation with boron and copper in various physical and chemical conditions, namely carrying satiation without application of an external magnetic field (EMF) and in its simultaneous imposition . Studies have shown that the use of EMF when applying boride coatings allows in 1.5 – 2 times reduce the duration of saturation detail and get coatings with high hardness and wear resistance.

Established that the application EMF on carbon steels formed a continuous, homogeneous boride layer, thickness is 2 times higher than the boriding without EMF. On the diffraction patterns of the surface layers of boride coatings obtained after boriding at application EMF fixed presence phases FeB and Fe₂B, the redistribution of the proportion of boride phases, the change of the crystal lattices and the decrease in the volume of the unit lattice phase FeB. When the complex is saturated steel 45 with boron and copper diffusion layer is composed of the phases FeB, Fe₂B and Cu. Chemical heat treatment with the simultaneous action of EMF leads to the formation of phases in the diffusion zone FeB and Cu, crack resistance layers obtained after saturation with boron and copper increases to 2.23 MPa · m^0,5 compared to 1.12 MPa · m^0,5 for boride coatings obtained without action EMF .

Formation diffuse boride layers under the action EMF improves tribological characteristics and leads to an increase in wear resistance of 2.2 – 2.6 times.

In this paper was investigated the formation of complex diffusion boride layers on metastable austenite Cr-Mn-N steel powder method. Calculate the value of the diffusion coefficient in different physical – chemical conditions and the thermodynamic potential chemical reactions. Defined phase composition layers obtained on the metastable austenite Cr-Mn-N steel. It is established that the application of an external magnetic field (EMF) leads to a redistribution of the proportion boride phases in the surface layers, changes the period of crystal lattice and increasing the diffusion coefficient.

In this paper we study the structure, phase composition, microhardness, crack resistance, wear resistance boride coatings obtained at complex saturation with boron and copper in the application of an external magnetic field (EMF). Investigations have shown that this method allows the application of boride coatings in 1.5 – 2 times decrease the duration saturation detail, and receive coating with high hardness, wear resistance, crack resistance.

It is established that the application EMF formed a continuous, homogeneous boride layer with thickness coatings in 2 times higher than boride coatings without EMF for the equal duration of the process. When imposing EMF in boride layers observed the redistribution quantitative relation boride phases, namely: decrease of volume phase FeB, and on diffractograms surface layers boride coatings obtained after boriding fixed presence phases FeB and Fe₂B. After complex saturation boron and copper in the application of external magnetic fields fixed phases FeB and Cu.

The researches have shown that the highest spalling stress value is reached in boride phases, obtained in powder environments with copper powder at the application of EMF, and respectively is 420 compared with 225 MPa for coating obtained without EMF. Increased shear stress values in complex layers obtained after saturation with boron and copper caused by the formation of phases more viscosity, for which crack K_1c in 1.4 – 2.0 times higher than the initial boride phases FeB and Fe₂B.

Application of EMF at boriding improves tribological characteristics of coatings: decreases coefficient of friction and increase in 1.5 – 2.5 times wear resistance.

It was investigated the structure, phase and chemical composition, thickness diffusion boride layers obtained after boriding and complex saturation boron and copper with simultaneous action an external magnetic field (EMF) on solid alloy T5K10. It was established that the application of an external magnetic field allows to intensify the process of diffusion saturation hard alloys boron and by 2 hours chemical – thermal treatment with simultaneous action EMF get such thickness diffusion boride layer which is formed by 4 hours chemical – thermal treatment without EMF. It was found increase microhardness diffusion layers formed on the hard alloys on 2 – 2.5 GPa (30 – 30.5 GPa) that is associated with a decrease areas of coherent scattering and as a result increase operating parts that work in conditions of intensive wear.

The non-equilibrium thermodynamics analysis of the eutectoid transformation is executed into carbon steel. Onsager’s equations of motion are built for the model thermodynamics system describing eutectoid transformation. Dependences of basic kinetic pa-rameters of process are expected are speeds of height of pearlite and inter-plates distance from the size of subcooling became for the sta-tionary process of eutectoid transformation.

The results of studies wear resistance of boron coatings alloyed with Сu, V, Nb, Cr or Ti under dry friction – slip in the air, and it was determined that the best coatings are the boride layers alloyed with copper. Alloying with copper inereases wear resistance of boride layers in 3 times. When alloying of boride layers with niobium wear resistance increases in 2,8 times, with titanium – in 2,4 times, with chromium and vanadium – in 1,5 times. Wear resistance of boride coatings alloyed with copper under dry friction – slip 14 times higher than wear resistance of bronze of Cu – Al – Mn system and wear resistance increases when applying boride layers alloyed with copper.

In this paper it was investigated the formation of complex boriding diffusion layers on metastable austenite Cr-Mn-N steel powder method. Defined phase and chemical composition, thickness, microhardness and wear resistance obtained by layers of metastable austenite Cr-Mn-N steel. It is established that the application of an external magnetic field (EMF) leads to a redistribution of the proportion boride phases in the surface layers of the crystal lattice period changes. EMF allows in 1.5 – 2 times to reduce the period of saturation details, microhardness diffusion boride coatings increase to 20,5 – 21 GPa and increase their wear resistance in 2.4 – 3 times compared to steel without protective coating. Boriding a magnetic field will increase the microhardness boride coatings 6 – 7 GPa compared to the boriding without application of a magnetic field.

It is known that the formation of oxide nanopowders takes place in the complex process including as non-isothermal and isothermal stages. In case of powders isothermal heat treatment led to realization of sequential process at transition from amorphous state to crystalline state, in particular, dehydration, crystallization, disintegration of linked nanoparticles in amorphous matrix and ensuing growth of crystals. In this work the questions of forming of particles and ceramic based on these nanoparticles are discussed. The influence of particles characteristics which synthesized at different temperatures on kinetics of isothermal sintering is estimated. It was shown that particles size and surface characteristics influence on kind of diffusion which is realized at ceramic sintering. The possible mechanisms of isothermal stage of nanoparticles and ceramics forming are discussed.

A new approach to design of oxide ceramic-ceramic nanocomposites instead of industrial technical ceramics has been proposed. The use of mixing of liquid solutions of reagents instead of powders mixing allows entering in the matrix material the oxide dopants in supersaturated concentrations. The synthesized nanoparticles contain a potential for the formation of various structures. By the controlling of heating regimes during nanopowders sintering processes we can control the diffusion processes on the particles volume and boundaries. The decomposition of initial supersaturated solid solution during heat treatment (especially at fast sintering) can lead to formation of multilevel nanocomposite structure in the ceramic matrix with enhancing mechanical, electrical, optical and magnetic properties. It is established on the example of zirconia that even a slight amount of aluminum oxide, nickel oxide, zinc oxide leads to a significant change of the nanopowders and ceramics properties.

The results of studies on the application of complex boron coating powder method on hard alloys. Defined phase and chemical composition, thickness and microhardness of the coating on alloys.

It was established that after diffusion saturation of hard alloy in boron mixture for 4 hours formed coating with boride phases TiB, WB, CoB and WC, TiC, whose thickness is 50-60 microns. At complex saturation with boron and copper for 4 hours diffusion saturation formed coating with boride phases TiB, WB, CoB and WC, TiC and separate inclusions of copper with a thickness of the diffusion layer up to 70-80 microns.

Boriding and complex saturation with boron and copper allows in 2 – 2.5 times increase the microhardness of the surface layers of hard alloys, that in turn leads to increased wear resistance.