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

The object of the study was carbon particles obtained by the method of self-propagating high-temperature synthesis. The purpose of the work is the development of compositions and technologies for obtaining competitive composite materials modified with low-dimensional carbon modifiers based on vegetable raw materials.

The paper considers the impact of functionalized nanosized carbon particles on the physicomechanical characteristics of composite materials based on polyamides. The concentration of the modifier varied both in the field of “doping” concentrations and in the field of concentrations used in the industrial production of nanocomposite materials based on polymer matrices. It was found that the use of cryogenic treatment of the initial polyamide leads to an increase in physical and mechanical characteristics. The introduction of nanodispersed particles in the field of “doping” concentrations increases the strength and hardness of the developed compositions based on a polyamide matrix.

Physicomechanical and adhesion characteristics, specific surface energy of vacuum coatings formed on high-speed steels of the P6M5 type subjected to processing at cryogenic temperatures are investigated. The structural transformations occurring in vacuum coatings formed on steel substrates with subsequent processing at low temperatures were studied. A change in the tribological characteristics of titanium nitride coatings during subsequent processing in a cryogenic liquid is shown.

A statistical model is proposed to analyze the relationship between the clustering coefficient (CC) and the temperature and atomatom interaction potential. CC is defined as the ratio of the number of atoms in clusters to the total number of atoms in a system. The proposed technique is based on the statistical concept of entropy. The clustering coefficient is considered for the equilibrium state.

It was analyzed the methods of constructions the matter with maximal of packing coefficient when the objects consist of the particles with forms either spheres or rods or plates. It was calculated the relations the partial size for relating of maximal packing coefficient. As examples of objects with coefficient of packing theirs particles we look on abrasive materials and products of the powder metallurgy and solid fuel etc.

Debye’s temperature θ_D is the temperature border between areas, C_μ^V(Т) has constant value and, when T<θ_D, begins to decrease monotonically. θ_D is the crystal parameter, which allows to calculate the dimensional border between macro- and nanostates. The statement which is found in scientific discussions that θ_D depends on temperature is incorrect because it contradicts modern crystal-physical theories. The numerical value θ_D is defined experimentally and is related to the structure of crystals and to the processes taking place in them.

Geometrically, the reciprocal lattice is built on the basis of the lattice of the crystal according to the rule
*
a j ak jk , where
the vectors
*
a j , ak are the periods of the crystal and reciprocal lattices corresponding  jk  0 at j  k and jk  1 at j  k (j, k = 1,2,3). The “weight” of the reciprocal lattice node, determined by the structural amplitude of the crystallographic plane corresponding to it, should not be zero, since in this case the reciprocal lattice node will be homologous to any point of the reciprocal space outside the lattice. Crystals with Bravais I, F, C – type cells in the reciprocal lattice are characterized by super cells, periods of which are n – times larger than ∗ = −1, where a is the period of the lattice cell. With respect to complex structures, even if they are single-element, the period of the super cell of the reciprocal lattice can exceed ∗ several times. For a diamond crystal ∗ = 4∗under the super cell of the reciprocal lattice it is necessary to use the smallest parallelepiped, the “weight” of all vertex nodes of which is not equal to zero.

The structure of the diamond is usually represented as two face-centered cubic cell with the same dimensions, which are shifted relative to each other by the value of +/-(1/4.1/4.1/4) That is eight different ways. However, in this case, there is a possibility of only two enantiomorphous centers, which have the same ф (hkl ) j . They do not affect on the reciprocal lattice, but allow to explain, for example, the presence of twins. The introduction of the concept of the scattering center of diamond shows that his point group is Fm3m with the full symmetry formula 3L44L3(4L3i)6L29PC, whereas the generally accepted model of the diamond structure does not correspond to such symmetry. For example, the L4 axis is missing, C is not at the origin of coordinates, there is only one L3 axis along the diagonal along which the sublattices are shifted, etc.

Investigated the mechanisms of interfacial interactions in composite materials based on thermoplastic matrices modified with dispersed particles of silicon and carbon-containing compounds with high energy activity. It was found that the laser treatment of particulate and fibrous particles occurs comprehensive modification of the surface layer, which consists in shaping the development of the morphology of the surface layer and increase its energy. For the modification of thermoplastic matrix including high-viscosity (polyamides, PTFE) prospectively the use of dispersed fragments of carbon fiber (CF) fraction 50-150 microns, subjected to the effects of a short pulse laser, having developed the morphology of the surface layer and the presence of defects through thermal degradation. When using this modifier in an amount of 5-30 wt.% for filling PA6, PA66, PTFE provides increased of parameters deformation and strength characteristics due to the increased mechanical component adhesive interaction at the interface of "matrix-filler". An additional effect is realized in the processing of the surface layer of CF fluoride compounds oligomeric or polymer-oligomeric structure. The modified fluorinated hydrocarbon components fragments CF when laser pulse processing are exposed to the active low molecular weight products ablation, so that the surface layers are formed with a high affinity to the matrix polytetrafluoroethylene. The complex method of modifying CF is effective for highly filled fluoro composites containing 25-35 wt.% of carbon fillers due to the decrease in the probability of formation of cluster structures of the filler particles. Dispersed particles silicate (clay, tripoli, talc) and carbon (graphite, carbon black, shungite) when exposed to laser radiation susceptible to degradation with the formation of nanoscale fragments in a moving layer, thus increasing their activity in the processes of the interfacial interaction in the formation of composites based on oligomeric and polymeric matrices.

There were studied mechanisms interfacial interactions in composite systems based on dispersed particles of polymer materials (polyolefins, polyamides, fluorcontaining polymers) and modifiers of various composition and structure in the combination process in the units with intense mechanical action. There were established the effects of formation of products of mechanochemical interaction of active centers of modifiers particles and radical fragments of macromolecules degradation. The obtained results allow changing the technological paradigm of the creation of high-strength and highly filled engineering nanocomposites based on high-molecular matrix.

Are investigated mechanisms and kinetics of structural transformations polymeric substrates and of disperse particles fillers and modifiers exposed defocused laser radiation with energy in the range of 1.5 to 6 J. Installed effect of hardening the thermoplastic matrices (polyolefins, polyamides, of polyesters) when exposed to short laser pulses on a film sample thicknesses of 50-200 microns. The methods of structural analysis (IR spectroscopy, X-ray diffraction, DTA) showed, that the predominant mechanism of manifestation hardening effect is the formation of nano-sized structures in the film sample volume due to leakage of recrystallization processes. When exposed to laser radiation to disperse and fibrous particles of silicates, graphite, schungite, carbon fibers is implementing a complex effect of increasing the dispersion and the formation of advanced morphology of the surface layer with an increase in the proportion of nano-sized fragments whisker and lamellar habitus. When laser irradiation of fibers fragments formed developed morphology of the surface layer, due to the occurrence of thermal degradation processes that lead to the appearance of cracks and of globular indentations. Spectroscopy method of thermally stimulated currents (TSC – spectroscopy) established the effect of changing the energy state of the surface layers of substrates and particulate modifiers, which are characterized by extreme values of magnitude TSC – currents in the temperature range 193-523 K. The combined effect of energy and morphological factors provides the effect of increasing the activity of modifying components subjected to the laser processing. Changing the energy state of the surface layer of the polymer substrate has a beneficial bactericidal effect, increases the effectiveness of antiseptic treatment of medical devices used in medical practice. Are presented examples of the practical use of the established laws when creating polymer composites for metal-polymer systems for various applications.

There were studied features of the structure of composite materials on the basis of recycled thermoplastic (HDPE, LDPE, PP) modified by components of different composition and dispersion. It was established the hardening effect of the matrix of the composite with the introduction of the highly oriented fragments that preserve the structure after the completion of the technological cycle of manufacturing products by injection molding or extrusion. It was proposed the technology of thermo-mechanical combining of thermoplastic components while simultaneous modifying by components of different composition and structure. When modification of fluorinated nanoparticles ablation products is provided the effect of increasing the rate of extrusion and formation of hydrophobized surface layer of products. Nanoscale silicate modifiers (clay, tripoli, metals phosphates and oxides,) contribute to the thermodynamic compatibility of the matrix and the modifier polymer due to formation of a spatial network of physical binds in the volume of the composite. The obtaining technologies for products based on recycled composites that the parameters of deformation strength and tribological characteristics are not inferior to raw materials, but have a significantly lower cost of production.