• THE MAXIMAL VALUES OF PACKING COEFFICIENT FOR PARTICLES WITH DIFFERENT FORMS

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 4, pg(s) 194-197

    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 AND DIMENSIONAL BORDER BETWEEN MACRO – AND NANO STATES

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 1, pg(s) 49-52

    Debye’s temperature 0D is the temperature border between areas, CМ/V(Т) has constant value and, when T<0D , begins to decrease monotonically. 0D is the crystal parameter, which allows to calculate the dimensional border between macro- and nanostates. The statement which is found in scientific discussions that 0D depends on temperature is incorrect because it contradicts modern crystal-physical theories. The numerical value  D is defined experimentally and is related to the structure of crystals and to the processes taking place in them.

  • THE GEOMETRICAL CRITERIONS OF NANOPARTICLES

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 12, pg(s) 503-505

    The structure of the bulk crystals allow to determine the habit of the nanocrystales on their base only as a source point. It is impossible to neglect the size, form and influence of surface. The liquids surface relatively quickly passes to equilibrium form when free energy is minimum. Debye’s temperature is rather arbitrary parameter. Its determination is based on some approach. However this parameter is introduced to the reference books and is broadly used in the crystal physics. Proposed strategy allows defining habit maximum size of nanoparticles on the base well known physics representations. The L–value is determined the bounder between sizes where it can be done value description and where it’s necessary to take into account the particle sizes.

  • THE SYMMETRY OF NANOPARTICLES

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 11, pg(s) 477-480

    The physical properties of nanoparticles as modifiers are depend on their geometrical characteristics. These objects have 5- and 10-axis symmetry which is forbidden for crystals. The 3×3 matrices-generators of point groups of rotation in crystallographical and crystallophysics basises have as matrix elements 0 and ±1, except groups hexa- and trigonal in H-basis crystals. But these lattices too have 0 and ±1 as matrix elements for matrical representation of point moving in crystallographical basis. For describing the point groups of pentagonal and decagonal symmetries, instead of crystal lattices the so-named general regular lattices (GRL). The two dimensional GRL is known as Penrose’s sets. For 3-d pentagonal sets there are 14 groups of point symmetry, which are not crystallographic because their elements may be golden ratio.

  • FEATURES OF THE STRUCTURE OF MIXTURES NANOPOLYMERIC COMPOSITES

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 11, pg(s) 469-476

    It is investigated features of phase structure of metal-polymeric nanocomposite based on thermoplastic matrices. Effect of realization of reversible phase transition “nanometal – high-molecular metal-containing compound” which determines hardening, wear and thermal-oxidative degradation mechanisms is established.

  • ANALYSIS OF THE POINT GROUP OF DIAMOND CRYSTAL

    Industry 4.0, Vol. 3 (2018), Issue 6, pg(s) 319-322

    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.

  • THE COMPATIBILITY FACTOR IN MATERIAL SCIENCE OF MIXED ENGINEERING NANOBLENDS

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 8, pg(s) 341-343

    Features of the structure of blends obtained by thermomechanical blending of thermoplastic components with different molecular structure are considered. The possibility of formation of structures with different levels of ordering (from heterophase structure with a pronounced boundary between the components to the macrogomogeneous structure with high compatibility of matrix and modifying components) is shown. Under injection of nanosize particles with different chemical composition into the blends, a synergistic effect of simultaneously increasing the parameters of tensile stress-strain and tribotechnical characteristics of items and its resistance to thermal oxidation is achieved. Nanosize particles in the active state perform the function of a physical compatibilizer, forming a cross-linked structure with physical bonds in the volume of the composite. The engineering nanoblends with increased performance parameters have been developed.

  • ENERGY TECHNOLOGY ACTIVATION COMPONENTS FUNCTIONAL MATERIALS BASED ON POLYMERIC MATRIX

    Machines. Technologies. Materials., Vol. 10 (2016), Issue 7, pg(s) 51-52

    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.

  • NANOCOMPOSITE MATERIALS BASED ON THERMOPLASTIC BLENDS FOR THE TECHNOLOGICAL EQUIPMENT WITH A LONG SERVICE LIFE

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 3 (2017), Issue 3, pg(s) 92-94

    The composite materials based on polymer and oligomer blends with different thermodynamic compatibility have been developed. It is shown that for polymer and oligomer blends of products formed as result of the thermogasdynamic synthesis of fluorine-containing compounds, the ability of oligomeric matrix to multiply deformation and alternating transfer is the most important. In polymer-polymer systems formed in a melt by various technologies the most important factor is the structure of the boundary layers determining the parameters of the stress-strain and tribological characteristics of the composites. The effect of physical compatibilization during the introduction of nanoscale metal-containing and carbon-containing particles into the blend compositions has been established. This effect promotes the thermodynamic compatibility and resistance to the action of thermal-oxidative medium on composites.

  • TECHNOLOGY LASER MODIFICATION IN MATERIAL SCIENCE NANOCOMPOSITES FOR METAL-POLYMERIC SYSTEMS

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 2 (2016), Issue 3, pg(s) 8-9

    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.

  • LASER TECHNOLOGY IN MATERIALS SCIENCE NANOCOMPOSITE MATERIALS BASED ON THERMOPLASTICS

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 1 (2015), Issue 1, pg(s) 51-54

    The physicochemical and structural aspects of the modification of polymeric materials and fillers, laser exposure to a given intensity. Installed effects transform the morphology of the surface layers of dispersed, semi-finished fiber and membrane to form nano-sized components with increased vigour. Modification of certain process parameters laser that achieve predetermined functional characteristics. It sets the parameters of the effect of a significant increase of strength characteristics of film semi-finished products made of thermoplastic (HDPE, LDPE, PP, PA, PET, PTFE), due to the formation of spherulitic supramolecular structures. The energy parameters of the surface layers of composites, subjected to modification of a short-pulse laser exposure. Installed effect forming electrets structures and nano-relief, providing suppression of unfavorable biochemical processes in the application of products in practice. The results of the use of materials and products subjected to laser modification, engineering and medical practice.

  • STRUCTURAL PRINCIPLES OF FORMATION HIGHLY DURABLE TRIBOTECHNICAL MATERIALS BASED ON POLYTETRAFLUOROETHYLENE

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 1 (2015), Issue 1, pg(s) 25-31

    The preconditions of forming a structural paradox within the existing technological paradigm, which manifests itself in reducing the parameters of strength and tribological characteristics of composite materials based on polytetrafluoroethylene when administered in their composition of fillers and modifiers of different composition and geometry when the content of 15-20 wt. % Established effects of forming the structural conditions derating improved performance due to the formation of cluster structure of the binder particles (PTFE) and the modifier. The effective technological methods to ensure reducing the likelihood of cluster components in the manufacturing process of highly composites with a filler content of 20-35 wt. %. The technology of producing high-strength wear-resistant fluorine composites, 1.5-20 times superior to common parameters analogues produced under the trademarks "Flubon", "Fluvis", "Superfluvis.". We consider the effective use of highly fluorine composites in mechanical engineering, chemical industry and energy.