Advanced composite materials: production, testing, applications

Resume : Thanks to their extremely high melting point above 3000°C and their unique combination of thermo-physical and engineering properties, ultra-high temperature ceramics (UHTCs) and coatings on their basis are envisaged as promising candidates for application at very high temperature. Among various compounds, ZrB2 has several advantages over other metal-based borides and carbides. One critical issue in the production of ZrB2-based ceramics is the achievement of fully dense bodies/coatings, which is the base-line condition to achieve good thermo-mechanical properties and oxidation resistance. Owing to the strong covalent bonds featuring all UHTCs, temperature above 2000°C and the application of pressure are required to densify these compounds. However, the microstructure deriving from such extreme processing conditions are coarse, with trapped porosity and hence with poor oxidation and mechanical performances. The addition of specific sintering additives has the twofold effect of decreasing the sintering temperatures down to 1650°C, and of notably modifying the performances at high temperature. This work aims to the development of ablation resistant UHTC coatings for the protection of future reusable space vehicles that should survive harsh earth and/or planetary re-entry conditions. For this purpose, selected UHTC compositions on the basis of ZrB2 (i.e. ZrB2-5WC-3SiC and ZrB2-15MoSi2) have been deposited by means of a new Shrouded Plasma Spray (SPS) technique under atmospheric conditions. A preliminary stage of the work consisted on the development of feedstock powders suitable for thermal spray processing, thus the morphology and size distribution of the powder particles were optimized to reach a good flowability and optimal processing conditions with the SPS system. Relevant SPS process parameters have been optimized based on the resulting coating microstructure and composition. Collected results led to the conclusion that the developed coatings are essentially composed of ZrB2 as main phase, indicating the low decomposition of the different feedstock powders in the plasma plume. Coatings have been applied on different type of Ceramic Matrix Composites (CMCs) (i.e. C-C, C/C-SiC) with dense structures, good adhesion to CMC base material and apparently good thermo-cycling resistance. Moreover, preliminary ablation and high temperature cycling tests have demonstrated the potentiality of the developed UHTC coatings to successfully withstand extreme thermal shock conditions without peel-off (critical delamination failure). Acknowledgements.This work has received funding from the EU FP7 Project “Super Light-Weight Thermal Protection System For Space Application" (LIGHT-TPS) under Grant Agreement no. 607182

Resume : ZrB2- MoSi2 composite powders have been obtained by carbo-thermal synthesis on a specially designed equipment and coatings were applied on C/C substrates by shrouded plasma spray method. The regimes of deposition and the optimal powders size have been determined. Some mechanical properties were measured by indentation method (hardness, fracture toughness, tension strength, compression strength, as well as microstructural (grain-boundary) strength).It was shown that the coating has relatively high hardness values, which are typically characteristic of zirconium boride ceramics. Herewith, a transition layer between the carbon and the coating has lower hardness values and it can be associated with its complex composition. The absence of differences in the length of the cracks from the corners of the prints propagating along the interfaces between the various layers and perpendicular to them indicates that the resistance to cracks propagation along and perpendicular to the interfaces for the investigated layers and interfaces is isotropic. It points out that the strength of the interfaces is the same as that of the materials adjacent to these boundaries and the absence of significant internal stresses or their relaxation. It testifies the stability and availability of such coatings application. The applied coatings were subjected to ablative testing with HHO flame.It has been determined that the coating increses the resistance of C/C composite to ablation.Acknowledgements.This work has received funding from the EU FP7 Project “Super Light-Weight Thermal Protection System For Space Application" (LIGHT-TPS) under Grant Agreement no. 607182

Resume : ZrB2- based dense ceramics with different sintering agents were obtained by the hot pressing and vacuum hot pressing modes. The principles of UHTCs structure and properties formation have been developed. It was determined that structure formation at sintering and shrinkage kinetics are determined by the formation of diffusion zones in the interface. In these areas the processes of phase transformations which determine the adhesion take place. Adhesive characteristics determine microstructure (grain-boundary) strength which was identified by us by the indentation method for the first time. This grain-boundary strength determines mechanical and service properties and correlation dependences of microstructure strength on other mechanical properties (fracture toughness, tension strength, compression strength) allow to create materials with necessary properties. The dense ceramics were subjected to oxidation at 1550 and at 1650°C for 15 minutes and repeated 1-3 times in a bottom-loading furnace. It revealed that method of obtaining influences oxidation resistance of the ceramics. Herewith, ceramics obtained by vacuum hot pressing showed higher resistance to oxidation compared to the other ceramics obtained by hot pressing, retaining the pristine ZrB2 under a thin outermost SiO2 glassy layer. Among the investigated materials, none showed oxide spallation and the best results were achieved when ZrB2 was sintered with solely MoSi2 or simultaneous addition of MoSi2 and CrB2. Acknowledgements.This work has received funding from the EU FP7 Project “Super Light-Weight Thermal Protection System For Space Application" (LIGHT-TPS) under Grant Agreement no. 607182

Resume : Scientists of all world space powers are currently engaged in creation of reusable spacecraft, providing a significant reduction of launch costs. One of the main problems in their development and operation are extremely high temperatures, which affect the surface for a sufficiently long period of time when flying with hypersonic speeds in the Earth's atmosphere. With traditional expendable launch vehicles, this task is solved by using of ablative coatings, but for reusable spacecraft different approaches and materials in the construction design should be applied. Along with the functional properties of the materials it should be taken into account their mass parameters which is the main criterion during their final selection. The objective of this work is selection of ceramic materials for the construction of hypersonic spacecraft, operating temperatures of which are up to 1200˚ C for 500 launches. The major drawback, limiting the use of ceramic materials, is their brittleness due to the presence of structural defects, which are compounded at each process step of ceramic manufacturing. Reinforcement of ceramic materials can increase their crack resistance. New promising class of materials - UHT ceramic has a very high melting point (about 3500 K), thermal stability, good thermomechanical and thermochemical properties and high oxidation resistance in the atmosphere reentry conditions, but it has sufficiently high specific mass - 4000-6500 kg / m3, therefore its application is effective at temperatures of 1500 - 1800˚ C. For structures, operating at temperatures up to 1200˚ C, it is expedient to use ceramic materials with appropriate working temperature range and lower density (2.5-3.5 g / cm3). Such a heat-resistant material for the RSC structures was developed by experts of the Kiev Polytechnic Institute and Yuzhnoye State Design Office. This is the ceramic, based on refractory boride and boron carbide reinforced with ceramic fibers. It was developed a heat-resistant structures manufacturing technology of such materials based on fundamentally new method of growing crystals of refractory compounds with non-crucible zone melting, created at Kiev Polytechnic Institute.

Resume : It was first when the ideas of thermodynamics of irreversible processes in the reaction sintering of powder metal alloys were put into practice. During sintering of metal alloys non-equilibrium reaction processes lead to the complete elimination of inheritance of structural defects inherent in the powder material. Thus the material improves its physicomechanical and technological properties. The theoretical research results of nonequilibrium topochemical reactions at high temperature oxidation deliberately allowed choosing the composition of the alloy which formed a stable protective film on its surface. All this is implemented in the development of a new generation of heat resistant alloys stable under cyclic stressing. Thus a new heat-resistant dispersion-hardened alloy based on niobium with reduced density of 5.558 g / cm3 was developed and it is much lighter than metal alloys used for thermal protection of reusable space systems. Technology of reaction sintering of the material based on niobium was implemented. The heat resistance of the alloy has been investigated. It has been established that the material is suitable for operation under temperature cycling to 1200 0C, as it withstood 100 cycles of heating and cooling to room temperature. The test material has lost only 11% of its mass over the full test period.

Resume : Textile fabrics on the base of carbon fibers and yarns may be used for protection from electromagnetic radiation. Carbon fibers and yarns for such fabrics are usually produced from viscose yarns by means of their chemical and thermal treatment. In this case viscose yarns are subjected to the processes of pyrolysis and carbonization. Yarns from such carbon fibers have the low elastic modulus so they may be treated on knitting machines with production of various combine interweaving. Such fabrics are characterized by enhanced elasticity and volumability. Knitting structures are very promising for creation of shielding fabrics (protection from electromagnetic radiation) because volume structure of knitted fabrics allows to realize physical effects promoting multiple reflection and absorption of electromagnetic waves. Furthermore knitting technology allows to use another kinds of fibers including cotton, metal, synthetic together with carbon ones for production of combine textiles. It allows to create a complex of required functionalities combining high mechanical properties (elastic modulus and strength) with shielding ability and tribotechnical characteristics (in corresponding composites) and other service properties in combined textile structures. Within the framework of FIBRALSPEC project activity weft-knitted combine fabrics consisting from straight high modulus carbon fibers from PAN fibers and ground fibers from low modulus carbon fibers from viscose fibers had been developed. In such kind of materials it is possible to combine fabric high strength due to weft yarn and fabric volumability created by ground yarns. For the enhancing of the bulk properties textured (bulk) yarn produced by the original technology of viscose directed shrinkage including knitting of viscose fabric, its thermal treatment with the following fabric untangling into carbon yarn. The technology of production of textured carbon fiber with given degree of volumability had been described. The examples of its application for weft-knitted and woven fabrics had been presented. Also the materials structure and properties (carbon fibers and fabrics) had been presented too. The results of mechanical and shielding tests for combined textiles and their dependencies from the composition and structure of fabrics had been described. On the base of obtained results some recommendations concerning industrial possibilities for weft-knitted and woven fabrics containing carbon fibers and yarns had been made. Acknowledgements This work has received funding from the EU FP7 Project “Functionalized Innovative Carbon Fibres Developed from Novel Precursors with Cost Efficiency and Tailored Properties” (FIBRALSPEC) under Grant Agreement no. 604248

Resume : Structural defects of as-cast single-crystalline CMSX-4 turbine blades were studied. Nickel-based CMSX-4 composite material consist mainly of two phases: one phase - forming the matrix and another one - which occurs in reinforcement. The blades were obtained by the Bridgman technique and cut along withdrawal direction. Longitudinal microsections were examined by X-ray diffraction methods complemented by Scanning Electron Microscopy (SEM). Back reflection Laue method and scan diffraction mapping were used to crystal orientation studies. X-ray topography of Auleytner projection technique with divergent beam was used. The dendrites array were visualized by macro-SEM images. It was stated, that many structural defects, such as local crystal misorientation and local internal stresses formed during growth process, have their origin near the walls of the mould. The defects areas spread out from the mould surface over the interior of the blades, perpendicular to the crystallization direction. It was observed that the defects are created in the area where the dendrite cores propagation is confined by the mould walls. Those effects occur more frequently in the places where the lateral cast section changes and mould surface is uneven.

Resume : Recently the advanced ceramic group in Ben-Gurion university of the Negev, Israel reported on new family of low temperature reaction bonded boron carbide composites. It was demonstrated that fully dense B4C-Mg, B4C-AZ91 alloy, B4C-Mg,Si (eutectic) and B4C- Al alloys composites can be fabricated at a significantly lower (750–1000 °C) temperature range. The key feature of the novel approach is based on the Mg-vapor atmosphere, under which the infiltration process is carried out. The microstructure and the mechanical properties of the composites will be described and discussed. It was concluded that the formation of the deleterious aluminum carbide (Al4C3) depends on the presence of free carbon in the boron carbide powders. In The present talk is concerned with the latest advancements in the fields of reaction-bonded boron carbide.

Resume : In the implementation of the concept of high-power (2,5 kW) electron-beam welding tool of new generation for fitting and repair works in space technological process has developed, This process allows in one vacuum-thermal cycle to receive complex electronic unit which has necessary strength, vacuum tightness, working temperature, resistant to thermal cycling and electrical breakdown. Working properties of the samples of location ceramic-metal assemblies of high-voltage cathode block were tested and has been received following data: bending strength ? ~ 200 MPa; operating temperature from 500 ? 700 °C up to 750 °C; vacuum tightness was determined by the method of pressure testing, but at high pressure up to 4-5 atm joints vacuum tightness was fully preserved; resistance to thermal cycling by regime 500 ? 20 ? 500 °C in vacuum and in air after 30-50 cycles vacuum tightness and strength are fully preserved. High-voltage insulator of electron-beam emitter which has been made from three metal units (high-voltage insulator, pin, cathode unit) was tested by the following parameters: a) vacuum tightness; b) high-voltage tests between metal electrodes (covar and stainless steel). Vacuum tightness test showed that all welded- brazed joints have allowed reach and save vacuum up to 1 x 10-7 torr (1 x 10-5 torr is sufficient). High-voltage tests showed that at voltage of 5 kV (more than 2 times exceed allowable voltage) electrical breakdown was not observed. Electrical resistance tests showed that resistance between electrodes was from1 up to 1,5 GOm when allowable resistance is 0,5 GOm.

Resume : Herein, we present the formation of PMMA/ZnO porous nanocomposites by in situ synthesis of ZnO nanoparticles (NPs), either by pulsed laser light irradiation or by thermal treatment of polymeric films mixed with zinc acetate as NPs precursor. The laser irradiation was used to obtain space-selective nanocomposite formation, offering the possibility to grow NPs in a desired area of the polymeric film. Interestingly, the laser irradiation also changes the morphology of the film leading to the formation of a porous structure homogeneously decorated with ZnO NPs, in only one single step. Alternatively, a thermal treatment was used to induce the homogeneous formation of ZnO NPs on the surface and in the whole volume of PMMA electrospun micro-fibres. In this two-step process, the first step is focused on the formation of the PMMA/zinc acetate fibres by electrospinning and the second step deals with the in situ synthesis of the NPs by thermal treatment, resulting in PMMA fibres homogeneously decorated with ZnO NPs. The obtained nanocomposites show multifunctional properties such as high thermal stability, gas absorption, UV-light switchable hydrophobicity and antibacterial activity. The present findings demonstrate the versatility of using the in situ synthesis approach for preparing nanocomposites characterized by crystalline NPs homogeneously dispersed in high surface area polymeric matrices, opening the possibility to extend their use in diverse applications.

Resume : Nanostructured amorphous spherical carbon particles and graphite like flat ones had been synthesized from pine chips by the methods of hydrothermal treatment and catalytic carbonization. Characterization of the particles had been made by FTIR, XRD, SEM, TEM, RAMAN methods. . Produced particles had been used for modification of epoxy binder in carbon plastics containing high modulus carbon fibers. Carbon particles had been introduced into binder in amounts 0,2-0,7 w.% by means of their trituration in less viscous binder component with the following ultrasonic dispersion .Modified binder had been combined with CF on the special laboratory stand and as a result the samples of microplastics had been produced. Such microplastics had been tested by means of SEM (surface microstracture). Furthermore their tensile strength has been studied. The results of tests showed that introduction of nanostructured carbon graphite like flat particles into binder results to enhancing of carbon plastic tensile strength up up 30 %. Using of amorphous particles for the binder nanomodification left the tensile strength of microplastic unchanged but at the same time microplastic plasticity had been increased in essential manner, increasing of relative deformation was equal about 50 %. Acknowledgements.This work has received funding from the EU FP7 Project “Functionalized Innovative Carbon Fibres Developed from Novel Precursors with Cost Efficiency and Tailored Properties” (FIBRALSPEC) under Grant Agreement no. 604248

Resume : The interphase between fiber and matrix plays an essential role in the performance of composites. Herein, we presented an effective method on the base of atomic layer deposition (ALD) process to modify the glass fiber and eventually fabricated multifunctional glass fiber/polymer composites. The enhanced interphase between glass fiber and epoxy was modified by depositing few tens nanometers ZnO nano-layer onto the surfaces of glass fibers via ALD at 200 ℃. Through a common fragmentation test, we found that the interfacial adhesion strength of single fiber composite was drastically increased. And with the increase of ZnO thickness, a critical thickness of ZnO of about 47 nm leads to the maximum interfacial strength which is more than 250% increase from the control fiber. Additionally, the fiber is functionalized by the ZnO nano coating since a conductive path was formed on the surface of the fiber and the UV sensing property was introduced to the fiber due to the photoconductive effect of ZnO. Consequently, introducing nanoscale semi-conductive oxide into fiber reinforced composite via ALD process can enhance the interfacial strength, and fuctionalize the composite.

Resume : In the present work, by considering the agglomeration effect of single-walled carbon nanotubes, free vibration characteristics of functionally graded (FG) nanocomposite sandwich curved panels resting on Pasternak foundation are presented based on the three dimensional elasticity theory. Through using a two-parameter micromechanical model of agglomeration, the vibration analysis of thick laminated panels with functionally graded nanocomposite sheets is carried out. The volume fractions of randomly oriented agglomerated single-walled carbon nanotubes (SWCNTs) are assumed to be graded in the thickness direction. An embedded CNT in a polymer matrix and its surrounding inter-phase is replaced with an equivalent fiber for predicting the mechanical properties of the carbon nanotube/polymer composite. To determine the effect of CNT agglomeration on the elastic properties of CNT-reinforced composites, a two-parameter micromechanical model of agglomeration is employed. In this research work, an equivalent continuum model based on the Eshelby-Mori-Tanaka approach is employed to estimate the effective constitutive law of the elastic isotropic medium (matrix) with oriented straight CNTs. Because of using two-dimensional generalized differential quadrature method, the present approach makes possible vibration analysis of cylindrical panels with two opposite axial edges simply supported and arbitrary boundary conditions including Free, Simply supported and Clamped at the curved edges. The convergence of the method is demonstrated and comparisons are made between the present results and results reported by well-known references; and have confirmed accuracy and efficiency of the present approach. The benefit of using the considered power-law distribution is to illustrate and present useful results arising from symmetric and asymmetric material profiles. The effects of two-parameter elastic foundation modulus, geometrical and material parameters together with the boundary conditions on the frequency parameters of the laminated FG nanocomposite panels are investigated. It is shown that the natural frequencies of structure are seriously affected by the influence of CNTs agglomeration. This study also serves as a benchmark for assessing the validity of numerical methods or two-dimensional theories used to analysis of laminated structures.

Resume : Pyrolysis mass-spectrometry (PMS) has been employed to investigate a process of thermal destruction of the secondary polyethylene (SPE), which was modified using hexamethylenetetramine (HMTA). The introduction of powdered HMTA in the polymer matrix on the basis of SPE, with a view to its mechano-chemical modification, leads to structural changes in the polymer matrix, to the formation of cross chemical bonds between macromolecules in SPE, with the participation of the ionic fragments of the collapse of HMTA, and to high content of gel-fraction of compositions, with increasing of content of HMTA in them. Оn the basis of the results, which were obtained by PMS and by measuring the content of gel-fraction of compositions on the basis of SPE, which are modified by HMTA, it was found that mechano-chemical modification of SPE using chemically-active component - HMTA, in the studied range of concentrations, accompanies by its decay into chemically active ion-fragments. This ion-fragments are extremely reactive and can react with polyethylene as with the matrix and with functional groups on the surface of the SPE with the formation of different composition of structural fragments. As a result of such processes the crosslinked structures form in the phase of the modified polymer, and affect the thermal and physico-mechanical properties of the compositions. The obtained results can serve as a basis of technological process of obtaining of composite material using secondary polyethylene as polymer matrix.

Resume : Silicon nitride is a promising structural ceramic material that was developed in a search for high strength and high toughness ceramics that could replace metals in advanced turbine and reciprocating engines to give higher operating temperatures and efficiencies. During the last few years new cost effective, high quality carbon based filamentous was developed in the form of graphene platelets (GPLs), also called graphene nanoplatelets (GNP), multilayer graphene nanosheets (MGN) or graphene nanosheets (GNS). These platelets demonstrate exceptional high thermal and electrical conductivity and an exceptional combination of mechanical properties. The aim of the present work is to investigate the influence of the addition of various kinds of graphene nanoplatelets on the structure and other properties of Si3N4 based composites prepared by high efficient attritor milling and sintered by spark plasma sintering. Acknowledgement Authors thanks to M-ERANET "Grace" Graphene-ceramics composits for tribological application in aqueous environments.

Resume : Wet spinning process is a common technique for manufacturing fibers from polymer solutions. Poly(acrylonitrile) (PAN) fibers, precursors of carbon fibers, are manufactured via wet spinning process because the decomposition of PAN occurs at temperature lower than its melting point. Many researches have been conducted focusing on wet spinning of PAN since 1980s as consumption of carbon fiber for advanced fiber composites has significantly increased due to its strong mechanical properties. Most of them, however, are related to additives in PAN and control of spinning parameters: solution concentration, flow rate, coagulation solvent composition, draw ratio, etc. In this study, we introduce a new parameter, electrical current, to wet spinning process and systematically investigate its effect on the mechanical properties of wet-spun PAN fibers. First, wet spinning facilities were prepared in lab scale, following literature The electrical current was imposed into PAN solution before PAN comes into contact with coagulation solvent. The mechanical properties of PAN fibers manufactured through electrical current-assisted wet spinning process were characterized and compared with PAN fibers manufactured from normal wet spinning process. Finally, the microstructural analysis was performed to investigate the effect of electrical current on the microstructure of PAN fibers and further their mechanical properties.

Resume : Carbon fibers, textured carbon yarns and various combined fabrics containing CF are the most promising reinforcement material for polymer based composites with different functionalities. It is known that the surface of carbon fibers (CF) produced from organic polymer precursors is characterized by the presence of defects in the kind of grooves and cracks. For the smoothing of the CF relief and increasing of adhesive strength on the boundary fiber- polymer binder usually it is proposed to use the coatings (glazing). Usually organic polymers (polyvinyl alcohol, epoxy resins), inorganic compounds carbon are used for such coatings. It is proposed to use for CF glazing graphene aqueous solution, produced by the authors by means of extraction from carbonized wood wastes (pine chips). Characterization of graphene coatings had been made by the methods of X-ray diffraction, electronic microscopy, thermal analysis, Raman spectroscopy. Investigations had been made for commercial fibers УКН-5000 (Russian Federation). Various kinds of preliminary treatments (hot water, chemical treatment by acids, oxidation heating) had been used for the commercial glazing deleting. Graphene coatings had been deposited by means of pulling of treated CF through graphene aqueous solution with the following drying at the temperatures not less than 200 С. The influence of graphene coatings on the strength of CF had been studied by the method of CF monofilament stretching. It was established that graphene coatings created on УКН-5000 fibers increase their strength up to 20 % in dependence of the kind of preliminary treatment. Acknowledgements.This work has received funding from the EU FP7 Project “Functionalized Innovative Carbon Fibres Developed from Novel Precursors with Cost Efficiency and Tailored Properties” (FIBRALSPEC) under Grant Agreement no. 604248

Resume : Layered double hydroxides (LDH) have been proposed as positively charged layered nano fillers for polymer composites. However to obtain polymer intercalation and optional platelets exfoliation counter ion issues limit their use for aqueous colloidal formulations comprising anionic stabilized polymers, usually used for organic coatings. To overcome this cutback acetate has been proposed as pristine counter ion, able to form volatile ammonium acetate in conjunction with the polymer counter cation. Furthermore metal acetates are convenient precursors for in-situ LDH and layered single hydroxide (LSH) synthesis in the presence of the polymer. In that context we recently have introduced the beneficial use of novel anionic bola-amphiphilic compounds for layered hydroxide hybrid formation, especially for LSH, a novelty in that domain. This report will focus on ex-situ LDH-acetate processing making use of these bola-amphiphiles as a formulation base for LDH based polymer composites. Comprehensive analysis for acetate and bola species along the processing steps, accompanied with real-time (SAXS) structural characterization of intermediates as well as of final coatings (SAXS, XRD, TEM) give insights into intercalation scenarios that depend on stoichiometry, bola composition and the polarity of the medium. The implications on mechanical (DMA) and barrier (oxygen permeability) film properties as well as on their corrosion inhibition properties on steel, studied with scanning Kelvin probe (SKP) are discussed.

Resume : The subject of the present research wasСf/SiC compositedeveloped at Virial LTD.Processing of Сf/SiCwas based on Si melt infiltration of the C/C preforms obtained via carbonization of carbon-fiber reinforced plastic (CFRP) preforms. CFRP preforms were formed via direct filament winding of carbon fibers infiltrated with LBS-1 resin 1 (loaded with SiC particles with grit sizes М40 and М7), subsequently cured in air, heat-treated under protective gas, machined and post-densified with additional resin infiltration.SiC matrix was formed via chemical reaction between silicon melt and coke within the preform. The processed Сf/SiC-composites were characterized for density, open porosity and Si volume fraction, with the average values being 1.85 g/cm3,0.95 % and 6 vol.%, respectively. Fig. 1 (a, b) shows the general view of the final CMC-parts, and Fig. 1 (с) shows the virtually pore-free cross-section of the sample. All filaments feature carbide phase contour and traces of residual Si. Carbide phase was also discovered inside fiber tows. The tribotechnical components based on Сf/SiC-composites may be used in wear-resistant friction units operating under heavy loads, e.g. in the next-gen submersible oil pumps. Such composites may also be processed into larger-size parts with increased impact resistance.

Resume : Molybdenum (tungsten)?nickel (cobalt) alloys and intermetallics can be deposited as continuous layers on a cathode from oxide tungstate melts. The composition and structure of the deposits can be controlled by varying the concentration of the corresponding components in the melt, the temperature, and the cathodic current density. An increase in the nickel (cobalt) content in an alloy with an increase in its concentration in the melt, a decrease in the cathodic current density, or an increase in the electrolysis temperature are most likely due to an increase in the fraction of the total current consumed to deposit nickel (cobalt) and to a decrease in the diffusion retardation for the ions of the more electrochemically negative component of the alloy.

Resume : The systems suitable for a high-temperature electrochemical synthesis on the surfaces of diamond, boron nitride, and silicon and boron carbides were selected on the basis of the thermodynamic analysis of the reactions of dielectrics and semiconductors with ionic melts and the study of their electrochemical behavior. Electroplating of the grains of dielectrics and semiconductors with molybdenum carbide favors the increase in their breaking load and wettability and in the efficiency of tools. Thermodynamic calculations showed that the most energy favorable process for boron nitride is its oxidation to gaseous nitrogen and boron metaborate or oxide. A compound of an element of group VI and carbon will be presumably reduced to this element in the pure state or to its oxide of an intermediate oxidation state. The most energy favorable process for silicon and boron carbides will be their oxidation to a metasilicate (metaborate) or silicon (boron) oxide. A compound of an element of group VI will be also presumably reduced to the elements in the pure state or in the form of an intermediate oxide.

Resume : Wettability processes are among the main factors in brazing and soldering procedure. High wettability of materials to be joined by brazing filler alloys determines both the process of joint formation and its high adhesion strength. In this work, the wetting and contact interaction of perovskite PNZT–ceramics with Ag-Pb melts were investigated in air. Dependence of contact angle Ag-Pb-O melts on perovskite ceramics in air at concentration of Pb and kinetics of wetting processes were studied. It was shown that contact angle for a pure Ag on PNZT ceramic substrate is 92 degrees, and it decreases up to 33 degrees if Pb concentration increases up to 5 at. %. Analysis of the perovskite ceramics/Ag-Pb-O alloy interface shows the presence of a transitive zone ~2 μm thick. The microstructure of the transition layers at the contact interface ceramic-to-metal was investigated and analyzed using thermodynamic calculations.

Resume : Influence of an electric current passing through the interface on wetting of some ceramic materials (zirconia, hafnium dioxide, barium titanate, et al.) was investigated in out early works. In this work the electrowetting of semiconducting tin dioxside by Ag-Cu melts was studied at 1270 K in air media. It was shown that after heating and electric current passing through the ceramics-metal interface (~ 30 min) the contact angle of Ag-39Cu decreases in cathode, and increases in anode SnO2-substrate. The microstructures of contact zones of ceramics and metal for cathode and anode substrates were studied and analyzed.

Resume : Shale gas extraction is going to become one of the most prospective solution for the oil&gas industry in the near future. The current and most practiced stimulation of unconventional gas reservoirs is hydraulic fracturing. This treatment is based on pumping a hydraulic fluid into the horizontal wellbore (up to 5000-7000 meters deep) at a high pressure to a value greater than the breakdown pressure of the formation and thus creation of conductive for shale gas fractures. The fracturing fluid properties strictly determine the creation and propagation of the fracture. The fluid viscosity is an essential rheological property that has impact on the net pressure, the near-wellbore drop and the pressure drop resulting from tortuosity between the wellbore and the propagating fracture. Moreover, quality of the fracturing fluid is a measure of proper high proppants concentrations transport, inhibition of microorganism growth, compatibility with the rock and pipes in the borehole, minimum friction pressures losses during injection, proper density (affects the surface injection pressure and the ability of the fluid to flow back after the treatment), controlled pH and formation-compatiblity ensuring low production costs. The fracturing fluid is mainly composed of water (90%) but also includes a variety of chemical additives (~1%) depending on the fractured reservoir (shales geology, well pressure and temperature) - each component serves a specific purpose. Remaining part (9-10%) accounts for the proppants – composites in a form of granules settled in the induced fractures (the rock closure prevention). The aim of the research was to verify improved ceramic proppants suspension in the fracturing fluid through the proper dynamic viscosity determination. Experimental studies concerned methylcellulose addition to the water sample at various concentrations. This commonly used organic constituent (polymer) induces gel formation by secondary crosslinking in the flowback but ensures low initial dynamic viscosity and stability in the proppants transport inside the rock (sedimentation avoidance). The outcomes indicate a significant impact on the rheological fluid properties (Zahn cup viscosity, dynamic viscosity), its density and pH in relation to the variable methylcellulose content (~1%) and thus prediction of the fluid behavior under mining conditions. It is also a basis for the further fracturing fluids modifications taking into account other groups of chemical additives.

Resume : We have studied the synthesis of intermetallic Fe-16 mass% Al of powders metals and compression it by hot forging. From a mixture of aluminum and iron powders at compression by hot forging at temperatures of 950 ° C, 1050 ° C and 1150 ° C was obtained a material, which consists of several phases Fe2Al5, FeAl, Fe3Al, and which has such properties: electrical resistivity 80-140uOhm*cm, density – 6,2 – 6,5 g/cm^3 and bending strength 500 – 420 MPa. After annealing the material at 1300 ° C and holding 2 hour is obtained a single-phase material which consists of a Fe3Al phase. On the samples were studied the structure and the complex physical and mechanical properties: electrical resistivity 130 – 140 uOhm*cm, density – 6,2 – 6,5 g/cm^3 and bending strength 1300 – 1100 MPa. Thus, we realized the possibility of intermetallic compounds by combining synthesis and compression to one stage, which allows to obtain a solid powder intermetallic Fe3Al, whose properties are not inferior to similar intermetallic compounds obtained by casting and rolling. Hence, this way of intermetallic production could be considered as resource saving technology.

Resume : Shock wave loading is one of the promising methods of processing of materials and characterized by high temperatures and pressures. The powders of Ti2AlC and Ti3AlC2 were synthesized at the Institute of Superhard Materials by the free sintering in a vacuum at 1350°C. Synthesized powders with Ti-Al-C phases were subjected to the shock wave impact loading with using industrial low blasting explosives on the flat pattern. The parameters of shock wave loading are: detonation velocity D=4 km/s, pressure about 2.5-3.5 GPa. Two samples based on Ti2AlC and four samples based on Ti3AlC2 composition were produced. The content of the MAX phase of structural type 211 after compacting was about 96 wt.%, obtained samples have the values of porosity in the range of 17-19 %. There is a partial destruction of the 312 phase under shock-wave loading, but weight content of Ti3AlC2 phase is 78-92 wt.%. Density of the compacts was of 3.6 to 3.7 g/cm3, but these values are significantly different from the theoretically attainable density of MAX phases and indicate a relatively high level of porosity (more than 13%).

Resume : Cellulose matrix, especially micro/nano composites (MNC), now are under intensive studies as their perspectives spread from ?paper electronics? and ?printing? to forensic examination and eco-friendly sorbents. At the same time there are a few data about properties of the ?MNC ? oxide? composites. In this work several sets of the composite samples, both MNC and MNC embedded with inorganic oxide dielectric (IOD) micro/nanoparticles were prepared and studied. The disks of composites were pressed from initial micro/nanosized powders of the MNC and mixture of the MNC and IOD (un-doped and doped with RE ions phosphates and vanadates). Some of the samples were undergone to carbonization via procedure of temperature treatment in the range 50 ? 2500C in ambient atmosphere. Morphology of the samples surfaces was investigated using optical and electronic microscopy. Temperature dependences of the specific capacity and dielectric losses tangent were measured in -100 ? 1000C temperature range when frequency of electric field varied from 1 to 100 kHz. As result, components of the complex dielectric permittivity, ?*, ?0 conductivity and other relaxation parameters were evaluated. Carbonization effect and a role of molecular anions of oxide components of composites have been discussed. Acknowledgement. Publications are based on the research provided by the grant support of the State Fund For Fundamental Research of Ukraine (project F64/32-2015).

Resume : One of the important aspect in the preparation of composite materials is the possibility of reaction between used components. In the case of composite from ZrO2 ? Ti system, the reaction could take place between the zirconia matrix and titanium particles during the sintering process. The diffusion of titanium into zirconia has been studied in previous works in order to verify the mechanism of zirconia stabilization by addition of titanium or titanium alloys. Experiments were conducted at temperatures higher than melting point of Ti (1667°C). Nevertheless, only little research has been reported on the ZrO2/Ti interface created at a temperature lower than the melting point of titanium. In the present work the experiment with the yttria-stabilized zirconia/titanium plates sintered in argon at 1450°C were presented. .The SEM observation made on cross sections perpendicular to the interface show that the reaction between components occurred. The study of phase composition (XRD) confirmed the formation of new phase of Ti-Zr-O system. In addition, the microhardness measurement was carried out perpendicular to the diffusion layer. Keywords Zirconium oxide, titanium, composite, diffusion Acklowledgements The work was done in frame of the project financed by National Center of Science (NCN), project DEC-2013/11/B/ST8/00309.

Resume : During diffusion welding of heat-resistant Ni-Cr alloys usually are applied high temperature and welding pressure, due to the presence of dense oxide film on the surface of the alloys. Because of oxide film the alloys have resistance to oxidation at high temperatures, but it complicates the welding process. The research object of this paper is obtaining of welding joints with porosity foils. Porosity foils were obtained by the technology of electron beam evaporation and condensation under vacuum. It is shown that the usage of such foils allows to activate the diffusion processes at the contact surfaces. Moreover, it allows to reduce the temperature and pressure of the welding process.Acknowledgements.This work has received funding from the EU FP7 Project “Super Light-Weight Thermal Protection System For Space Application" (LIGHT-TPS) under Grant Agreement no. 607182

Resume : Nanostructured CdS layer/organic P3HT:PCBM or ZnPc-4R:PCBM composites were formed on the indium-tin-oxide (ITO)/glass substrate with PEDOT:PSS composite film as the top electrode [1]. On the base of quasi-DC measurements of current-voltage characteristics (CVC) it has been found that CdS plays the role of an electron-transporting (hole-blocking) underlayer to rectify electron flow from the P3HT:PCBM bulk heterojunction to the ITO electrode. The application of investigated composite as PV cell have shown a few ways to their further optimization: (i) the thickness of CdS layer used in the above cells has to be decreased up to 100 m or even less; (ii) the surface of nanostructures CdS should be well controlled in order to provide good contact with the organic counterpart and to serve as a charge sink, respectively; (iii) the nanostructured CdS layer can work not only as a selective electrode, but also as an active component of the PV cell, for example, participating in dissociation of excitons generating in the organic layer and (iv) a clamped top contact of PEDOT:PSS has to be optimized. Solution of the above problems is believed to allow one to construct the inverted PV cells with better performance. So, the bifunctional role of the CdS nanostructured layer as a means to increase the interface with the active layer and as a bottom electrode with better electron affinity than ITO has been shown. Financial support of CRDF project No. UKE2-7035-KV-11. [1] D.O. Grynko, O.M. Fedoryak, P.S. Smertenko, N.A. Ogurtsov, A.A. Pud, Yu.V. Noskov, O.P. Dimitriev, Application of CdS nanostructured layer in inverted solar cells, Journal of Physics D: Applied Physics, 2013, 46, 495114.

Resume : The method of synthesis of oligomeric azoinitiator (OAICO) on the base of bifunctional monomer azoinitiator azo-bis-isobutyrohydrazone of cyclohexanone (AGN-CН) processed isophorone diisocyanate (IPDI) and of castor oil (CO) at molar ratio of AGN-CH-IPDI:CO =1:2 was developed one initiating center the OAICO 1/2 received with structure RХR, where R - is the castor oil block, and X is the initiator block. At molar ratio of AGN-CH-IPDI:CO = 2:2 the oligomeric azoinitiators OAICO 2/2 with two initiating centers was obtained with structure (RХ)n or R2Х2. Oligomeric azoinitiators have been studied by the method of IR- and UV-spectroscopy. Block copolymers of type (ABA)n (A – block of castor oil, B – block of oligostyrene) with various lengths of oligostyrene block were synthesized on the base of synthesized oligomeric azoinitiator of castor oil and styrene as monomer by the method of thermoinitiated radical polymerization. The BCPs were obtained at molar ratio OAI/St = 1/140, 1/200, 1/400 under the following conditions: at temperature 950С throughout 20 hours. In so far, as PAI formation through the reaction between the isocyanate groups of AGN-CH-IPDI and the hydroxyl groups of CO proceeds independently of the thermoinitiated polymerization of styrene, it was possible to prepare two series of polyblock BCPs of type (АBА)n (where A is the castor oil block, and B is the styrene block). The sequential one was obtained by the synthesis of PAI in the first step, and by subsequent radical polymerization of styrene thermoinitiated by PAI, while both reactions were carried out in a single step to prepare the simultaneous one. Relaxation transitions in the soft (castor oil) and hard (oligostyrene) blocks of new synthesized block-copolymers were investigated by the DSC method.

Resume : In this paper, nanocomposites based on sequential semi-interpenetrating polymer networks (semi-IPNs) consists of polyurethane (PU) and poly(hydroxypropyl-methacrylate) (PHPMA) were synthesized and investigated. 1,2-propandiolisobutyl-POSS (POSS, 1 and 10 wt%) was used as functionalized nanofiller for PU. The stoihiometric ratio [PU/POSS]/PHPMA=70/30 was in all cases. The nanocomposites were prepared by controlled swelling PU networks in HPMA and their subsequent photopolymerization with 2,2-dimethoxy-1,2-diphenylethan-1-one (IRGACURE 651, λ=340 nm). The effects induced by the POSS content (1 or 10 wt%) on the structural and thermal properties of the nanocomposites were investigated by DSC, TGA, SEM. From the DSC data the glass transition temperature (Tg) of the nanocomposites were found to increase with increasing POSS content from Tg=-61,1oC (pure PU) to Tg=-58,6oC (semi-IPN-30 with 10 wt% POSS). According to the TGA data at loadings of 1 wt% of POSS there is an observed increase in onset degradation temperature (Tonset) from 270oC for pure PU to 323oC for semi-IPN-30 nanocomposites with 10 wt% POSS. Maximum values of the thermal decomposition temperatures, defined as the second maximum of the TGA curves, shifts towards higher temperature: from 376oC for pure PU to around 387oC for all semi-IPN-30 nanocomposites. From the SEM images the homogeneous structure of the semi-IPN-30 nanocomposites becomes more segregated with increasing POSS content in the samples. We observed POSS particles aggregation in the form of rectangular microdomains at maximum POSS content. As a result the nanocomposites with more ordered structure are formed thus leading to obtain materials with improved thermal stability. The authors thank the staffs of the Center Collective Use of scientific Equipments (CCUE) NASU in IMC on research by DSC, TGA and N.G. Kholodny Institute of Botany NASU on research by SEM

Resume : For many decades, silver nanoparticles have been recognized as an antimicrobial agent and used in many fields including biomedical, food packaging, waste water treatment, etc. This explains the interest to the development of metal-polymer nanocomposites with controlled structure and properties. WAXS investigations show that transfer from pectin-P4VP IPEC (interpolyelectrolyte complexes) to pectin-Ag+-P4VP IPMC (interpolyelectrolyte-metallic complexes) is displayed on the diffractogram as a diffusion-type maximum at 2θm≈11,0о inherent to interpolyelectrolyte-metallic complexes. It is revealed that as the result of Ag+ cations reduction in IPMC bulk (with support from sodium boron-hydrate) “IPEC-Ag0 nanoparticles” nanocomposite is formed. It is shown that Ag+ reduction in IPMC under the effect of electric field takes place with formation of nanocomposite with higher metal content. By means of SAXS it is shown that relative level of structure heterogeneity grows up considerably in the following sequence: IPEC pectin-P4VP → IPMC pectin-Ag+-P4VP → nanocomposite IPEC-Ag0 (without electric field effect) → nanocomposite IPEC-Ag0 (effected with electric field). Thermomechanical analysis methods show that nanocomposite IPEC-Ag0 formed under constant electric field effect has higher glass-transition temperature Тg and relative deformation ε comparing with material received without field effect.

Resume : One of the most effective ways to improve the performance of cutting tool is deposition of coatings on its working surfaces. It is known that cutting of hardened steels with polycrystalline cubic boron nitride (PCBN) cutting tool is characterized by high loads with contact normal and shear stresses up to 5 GPa. In such conditions the substrate-coating system should be created wich facilitates the adaptation of working surfaces to machining conditions. Materials in amorphous and amorphous-crystalline state are characterized by advanced tribological properties. The creation of coating with such structure can lead to the positive effect due to the number of reasons. First of all the one should expect the declination of the residual stresses appeared as a result of crystalline growth. The next advantage is connected with low, in comparison with PCBN, Young modulus (Е ~ 200 GPa) and thus - high plasticity of contact layer of tool. The plasticity of coating determines an active adaptation of microgeometry of surface layer of cutting tool in the initial wear period. That leads to an increase of contact area and reduction of contact stresses. As a result, the probability of micro-cracking of surface layer of tool declines. Experimental investigation of machining of hardened steel with PCBN tool with amorphous-crystalline protective coating has showed that cutting forces and average contact temperature reduce up to 20 percent, and tool life increases on 25 percent in comparison with uncoated PCBN composite.

Resume : The aim of this study was to develop methods of modifying the industrial alkyd resins functionalized by oligomers, and obtaining on their basis of coatings with improved physical-mechanical properties. The non-isocyanate methods synthesis of polyurethane by reaction of cyclocarbonate and primary amino- group is the most technologically through accelerated reacted at room temperature. This avoids the use of toxic isocyanates and adverse reactions during the preparation of polyurethane materials and the use is available raw materials. The oligoamidurethane were obtained in the mixture by the interaction of highly unsaturated vegetable fats with aliphatic amines and cyclocarbonate soybean oil. The reaction mixture is thermostatically with stirring at 40 ºC for 5.5 hours. Have been received modified polymeric film-forming alkyd materials with high protective properties by interaction alkyd resin (varnish PF-060) and synthesized modifier (oligoamidurethane). It is proved, that at presence in structure alkyd 5 % oligomers result in substantial increase of parameters of durability at impact, elasticity and adhesion to a metal surface.

Resume : We have developed direction of the chemical modification of epoxide through introduction of urethane groups in ER without usage of toxic isocyanates. The using of cyclocarbonate oligomers (CCO) in the reaction with aliphatic amines leads to the formation of hydroxyurethanes. It is established regularities of the formation of polymers based on amine curing epoxy-cyclocarbonate compositions. High speed aminolysis of CCO determines the total curing process acceleration and the growth of system dynamic stiffness. It is established the nonmonotonic dependence of velocity and degree conversion of epoxy group (EG) and cyclocarbonate group (CG) from ratio ER: CCO. The oligomers ratio with maximum conversion rate of EG and CG is determined by some processes: aminolysis slowdown because of CG content growth, acceleration of EG conversion on account of hydroxyurethane fragment catalysis, system depletion of primary aminogroup during the initial stage of curing because of interaction with CCO. It has been considered the dynamic mechanical analysis, scan calorimetry, gel-analysis data of nonisocyanate EPU. It was shown the dependence of polymer glass transition temperature, elasticity modulus, heat endurance from ССО quantity. The modification composites based on nonisocyanate EPU have allowed to increase durability, adhesion characteristics, elasticity, energy of deformation of polymers without reduction of polymer resistance to water and heat. Modified by CCO epoxy resins, which are cured by different amines, allow to create nonisocyanate EPU with special properties (high-strength, water soluble, foam expanded materials and others).

Resume : Understanding the adsorption and desorption energetics of H2O molecules on surfaces is important for the development of new and more effective materials for water splitting technology. Presently, the importance of oxygen exchange materials (e.g. CeO2, perovskites) for thermochemical splitting of H2O is in focus. In the present study, the effect of different aloveal…. on the water adsorption energetics was investigated. Nanoscale doped CeO2 powders have been synthesized by a surfactant-based method. The as synthesized nano powders were found to be homogeneous solid solutions with a fluorite structure, where the lattice parameters changed with the dopants. The water adsorption enthalpy and coverage found to increases with the dopant level, which imply increasing in the surface enthalpies. XPS measurements show salute segregation farther more the presence of the salute influences the redux behavior of the cerium atom. The reasons for this behavior will be discussed.

Resume : CeO2 is an attractive material for various applications due to its physical, chemical and electrical properties. For example, CeO2 is a basic component in oxidative catalysis as well as sensors and fuel cell technology, where catalytically active surfaces and high ionic conductivity, well-known for CeO2, are essential. These applications are based on the easily formed oxygen vacancies in the fluorite structure of ceria due to the variable oxidation state of Ce ions (+3 and +4). Doping ceria with aliovalent cations to some extent may increase the oxygen vacancies while maintaining the cubic fluorite structure. These ceria-based materials found to have high ionic conductivity and enhance catalytically active surface. In the present work, the effect of neodymium on the formation of Ce3+ in nanoparticles ofCeO2 was investigated using X-ray photoelectron spectroscopy. The overall oxygen vacancies increased with the neodymium addition while the Ce3+ concentration was reduced. Nevertheless, the amount of OH species found at the surface increased with larger neodymium content.

Resume : Based on thermodynamic calculations of possible interactions between sodium tungstate and oxygen-containing compounds of boron, carbon, phosphor, sulphur, and VI-B group metals, the probability of possible reactions was evaluated. The experimental verification of the assumptions was accomplished by the methods of potentiometry and IR-spectroscopy. The possibility of existence of (reversible) equilibrium of molten systems with the electrodes made from VI-B group metals and their carbides was proved by the electrochemical measurements and thermodynamic calculations. The conditions of electrodeposition of nanostructured tungsten coatings from these melts were found.

Resume : Because of the aluminium coating onto some non-metallic materials, such as silicon nitride, are using for these materials brazing, it is of interest to study the aluminium nanofilm behaviour during annealing it in vacuum. In this work the changes in morphology of aluminium nanofilm 100 nm thickness were deposited onto sapphire, graphite, carbon glass, silicon carbide and silicon nitride and were annealed in vacuum of 1x10-3 Pa at temperatures up to 700 °C were investigated. It was found that the film onto all the investigated materials during annealing up to 600 °C retains its continuity. The film morphology modifications occur in the 630 – 700 °C temperature range. Nanofilm onto leycosapphire began disperse only after 10 minutes annealing at 650 °C with the dendrites formation and after 20 minutes annealing it dispersed at large fragments – islands. Aluminium nanofilm onto Si3N4 begin disintegrate at 630 °C annealing but it completely disintegrated after 20 minutes at 650 °C annealing. Dispersion beginning of aluminium nanofilm onto graphite, carbon glass and silicon carbide was detected only at 650 °C annealing and after 20 minutes exposure at this temperature it is completely dispersed. Nanofilm onto carbon glass disintegrated only after 1 hour at 650 °C annealing. In result of aluminium nanofilm onto graphite and silicon carbide at 700 °C annealing it dispersed at the separate large drops.

Resume : High pressure spark plasma sintering (HPSPS) was employed to fabricate polycrystalline Nd:YAG specimens with desired functional properties. Specimens fabricated under a uniaxial pressure of 300MPa at 1300°C at a heating rate of 50°C/min and holding time of 60 min displayed sub-micron microstructure and elevated mechanical properties, including resistance to thermal shock. Optical properties (i.e. spectral transmittance, fluorescence emission spectra and fluorescence lifetime)of the HPSPS-processed specimens were close to those obtained with specimens fabricated by conventional sintering procedure. Specifically, remarkable differences in threshold powerand laser slope efficiency were found and attributed to the variance inNd concentration in the specimens tested. The results of the present study indicate that the low cost and time-saving HPSPS process allows for the fabrication of polycrystalline Nd:YAG specimens with optical properties suitable for laser applications.

Resume : Segregation of defects to the surfaces and interfacesof ionic materials result in the formation of a space-charge potential (SCP).SCP is studied extensively for its critical role on functional properties. Although significant theoretical advances have been achieved, the experimental evidence in nanocrystalline ionic materials is indirect. Therefore, in this work, the electrostatic potential distribution in nano-scale grains of non-stoichiometric MAS (MgO∙0.95Al2O3,MgO∙1.07Al2O3and MgO∙1.27Al2O3) was measured by off-axis electron holography and compared to the distribution of cations and defects in this material as measured by electron energy-loss spectroscopy. In this manner, we studied the roles of composition, grain size and applied electric field on the formation of a space-charge region.We quantitatively demonstrated that regardless of grain size, the vicinity of MgO∙0.95Al2O3grain boundaries presented an excess of Mg+2 cations, whereas the vicinity of MgO∙1.07Al2O3grain boundaries included an excess of Al+3 cations.The degree of structural disorder (i.e., the inversion parameter, i) indicated that as-synthesized MAS were significantly disordered (i between 0.37 and 0.41), with valuesdecreasing toward equilibrium ordering values following annealing (i between 0.27 and 0.31). The application of an external 150 Vcm-1electric field during annealing further enhanced lattice ordering (i between 0.16 and 0.19).Such variations in the distribution of cations and defects should determine the SCP. However, using these measurements to calculate the SCP was not possible due to the wide range of values reported for formation energies of defects (0.82-8.78 eV). Consequently, we correlated local ionic ordering with electrostatic potential in non-stoichiometric MAS. The magnitudes of the SCP in both MgO∙0.95Al2O3 and MgO∙1.07Al2O3decreased following annealing from -3.4±0.3V and +2.0±0.2 V to -2.0±0.2 V and +1.6±0.1 V, respectively.Such results underscore the importance of comprehensive nanometer scale characterization of the chemistry and electrostatic potential and providing a comprehensive understanding of defects in complex oxides.

Resume : Carbon fiber activated nanostructured materials(CFANM) prepared by one stage pyrolysis of rayon have been investigated as materials of sorption action for using in medicine and environmental protection. As established they belong to group of granular–fibrillar composite anisotropic nanostructured materials which consist of different types of nanofibers and granular nanoparticles as carbon nanopackets withSiO2activation addition.CFANMhave widened systems of micro- (0,6<х<1,5 nm), meso- (1,5<х<200 nm)and macro-(х<300 nm)pores as well as specific surface area of 2800 m2/g.The total porous volume and microporosity increase with a degree of rayon transformation. For increasing the sorption characteristics of investigated materials their modification by oxidation of nitric acid solution of different concentration have been carried out. Proposed technology at the same activation extent and total porosity allows obtaining a different porous distribution and as a result supplies with regulative adsorption of toxic substances of different molecular mass by change of parameters for technological process.As established an application of proposed carbon fibrous nanostructured materials is one of most effective methods of detoxification therapy under poisoning by xenobiotics as well as poisons of chemical and bacterial nature. The processes of immobilization of biological active compounds such asa ferrocene, quercetyne, lipase, antibiotics, alkaline proteaseon the surfaces of prepared sorbents as well as sorption of organic components such as phenol,heavy toxics metals, low-molecular substance, albumin were investigated.

Resume : This research concerns investigation on medical grade polydimethyl siloxane (PDMS) elastomer irradiated by fs-laser. The motivation is based on the wide use of the PDMS material in medicine and medical devices. The application in the medical field is due to some of the main properties of the PDMS. Thus its high biocomatibility and biostability, mechanical flexibility and chemical stability, optical transparency from UV to near IR spectral region. The experimental setup consists of fs-laser system, optical parametric amplifier, optical elements and XYZ translating stage. The regenerative Ti:Sapphire amplified laser system has a pulse duration of 35 fs and 1 kHz repetition rate. The working parameters as laser fluence and number of pulses are varied. Specifically, the laser fluence applied is between 0.16 and 0.5 J.cm-2 and the number of consecutive pulses is from 102 to 104. Additionally, the wavelengths used in the experiments are 266, 355 and 532 nm. Tranches on the PDMS-elastomer MED 4860 surface are produced by the fs-laser processing and the material inside them is modified. Optical properties and morphology of the trances are investigated in terms of the laser beam parameters. Despite the low optical absorption of the native PDMS for UV, VIS and NIR wavelengths, successful laser treatment is accomplished due to the chemical transformations occurring below the polymer surface. The optical absorption and thus saturation caused by the incubation process is observed with the increase of the number of pulses. Such process increases significantly the efficiency of the laser ablation. The ablation depth measured is in the range of 4 ÷ 10 ?m for UV light and in the range of 10 ÷ 40 ?m for VIS laser treatment, respectively.

Resume : In modern medicine hydroxyapatite (HAP) is the most widespread material-substitute of damaged bone tissue due to its biochemical composition similar to hard tissue of all the vertebral being and high biocompatibility with the living organism. But hydroxyapatite based materials have poor physic-mechanical properties under heightened loadings. Basalt scale has been chosen for strengthening HAP and improvement of its physic-mechanical characteristics as well as because of its biological inertness. Stochiometric HAP of different fractional composition strengthening by amorphous – crystal basalt scale (0 %, 5 %, and 10 %) has been investigated in this work. Pressed samples were sintered under 700 оC, 800 оC, 900 оC, 950 оC, 1070 оC, 1250 оC and their phase composition and physic-mechanical (shrinkage) properties were investigated. Samples of HAP with 5 % of basalt scale which were sintered at 1250 оC demonstrated the best result. They exceeded ruling analogs by their mechanic parameters as well as they were compactness similar to bone tissue. In this case bone tissue is able to grow through implant material. X-Ray analysis showed β-ТКФ phase formation. This phase is the most compatible with the living organism. It was established that basalt scale sintered under 1250 оC was very stable in the media which imitated the media of living organism and it is biocompatible too. Thus, HAP strengthening by amorphous – crystal basalt scale is very perspective implant material.

Resume : Hydroxyapatite (HA) bioceramics doped with various ions are gaining more interest in the field of tissue engineering applications. Of the many trace elements or ions, fluorine is most commonly employed as an additive in HA due to similarity of HA and fluorapatite structures. Fluorine actively participates in bone formation, the processes of formation of dentin and enamel. In the present work highly porous glass-ceramics based on biogenic HA (BHA) and SiO2-CaO-Na2O glass with fluorine addition (0.3 wt. %) have been prepared by foam replica technique at sintering temperature 900 °?. Under sintering BHA decomposes with the formation of glass-ceramics due to the aggressive action of the glass phase, which results in forming phases such as: renanit NaCaPO4 (JCPDS, Card No. 76-1456), calcium silicate phosphate Ca5(PO4)2SiO4 (JCPDS, Card No. 21-0157), calcium pyroposphate ??2?2?7 (JCPDS, Card No. 33-0297) and impurities of HA Ca5(PO4)3(OH) (JCPDS, Card No. 09-432). Fluorine addition also leads to the formation of fluorapatite Ca5(PO4)3F (JCPDS, Card No. 02-0845), which was confirmed by IR spectroscopy results. It was established that fluorine introduction retains permeable porous structure of the material (porosity ~ 80 %) without compromising the structural and mechanical properties of the samples, as well as insignificantly reduces the solubility in vitro, which makes them promising for the treatment of bone diseases in orthopedics and traumatology.

Resume : Foregoing bioactive material for medical application has been obtained by impregnation of nanostructured biogenic hydroxyapatite (BHA) microgranules (?160 µm), prepared according with T? ? 33.1-22965991.002-2001 by 1 and 2 ml of colloidal solution of magnetite with following mechanical mixing impregnation powder. This composite materials were thermally treated in a nitrogen-containing medium at 500 º?, that less than the Curie point for magnetite (572 ºC), for 2 hours. ?hemical composition of prepared compounds (before and after thermolysis) have been controlled by photocolorimetric method. According to photocolorimetric analysis, material doped with 1 ml colloidal solution of magnetite had 0.59 (%) mass. of total iron before heat treatment, and 0.52 (%) mass. ? after it. For the sample doped with 2 ml colloidal solution of magnetite the amount of total Fe was 0.68 (%) mass. and 0.69 (%) mass. before and after thermolysis, respectively. Thus, this type of heat treatment keeps the chemical composition of the investigated materials.

Resume : Previously we have synthesized compositions based on oligooxypropylene fumarate, thriethylene glycol dimethacrylate and N-vinylpyrrolidone, which contain immunomodulator levamisole proposed for creation of bone implants. One of the necessary steps in creating biologically active composite materials intended for use as implants is the study of biodegradation under conditions close to the medium of the human body. The ability to biodegradation studied the change in their physical-mechanical properties and structure under the influence model biological medium 199 (BM 199), which imitates the blood plasma. Samples of composites were incubated in BM 199 at a temperature of 37 ± 1°C for the period of 1 and 3 months. Based on the results of physical-mechanical tests, after incubation in BM 199 of investigated composite materials, occurs decrease modulus of elasticity in compression, which indicates the course of biodegradation of polymer base these materials by ester and ether bonds (according to IR-spectroscopic) under the influence of BM 199. Therefore, the studied composite materials based on oligooxypropylene fumarate, thriethylene glycol dimethacrylate and N-vinylpyrrolidone, which contain immunomodulator levamisole have the ability to biodegradation and can be used as a basis for creating drug delivery systems.

Resume : The nanocomposites based on multicomponent polymer matrix consisting of polyurethane (PU), poly (2-hydroxyethyl methacrylate) (PHEMA), and nanofillers based on silica with mechanically activated surface and surface modified by aminoacid glycine are synthesized. The structure of the nanocomposites and thermodynamic parameters of polymer components with nanofiller interaction were studied. The structure of the created nanocomposites was investigated by small-angle X-ray scattering and was shown that modification of densil surface by aminoacid glycine leads to an increase of average size of the particles and to the formation of a rough surface of filler. Introduction of modified nanofiller into polymer matrix influenced the structure of the matrix: there is a complete disappearance of the structural features of semi-IPN in the nanocomposites. With the introduction of the modified nanofiller into polymer matrix the mass-fractal of spatial distribution of the particles is preserved. However, the surface roughness of the particles increases. The thermodynamic parameters of interaction between polymer matrix and nanofiller were investigated. It was shown that the free energy of mixing of polyurethane, PHEMA and semi-IPNs with filler is negative for systems with low content of PHEMA, and thus the energy is released during process of the nanocomposites formation, and dence, durable polymer layers on the surface of nanofiller are formed. With increasing the PHEMA content the free energy of mixing moves to the positive value, which is the result of competition of two processes: formation of dense surface layers on the surface of the filler, and the formation of interfacial layers with excess free volume. Acknowledgement The work was supported by the project N 6.22.7.21 of the STSTP “Nanoteсhnology and Nanomaterials” of Ukraine

Resume : Biologically active metal containing polyurethane materials based on colloid solutions of silver and copper naoparticles in polyether have been prepared. Obtaining of colloidal metals (Ag, Cu) solutions in polyether was carried out by Electron beam physical vapor deposition (EB- PVD). Metal nanoparticles concentration in obtained material compositions was varied from 200 to 600 ppm. Biological study of Cu and Ag nanometals containing polyurethane has shown that they exhibit bactericidal properties in relation to both gram-positive and gram-negative bacteria, and Candida fungi. Synthesized polyurethanes possess bacteriostatical effect on fungi - micromycets. Obtained biologically active metal containing polyurethane materials can be processed into goods for medical purposes (catheters, drains, films, grids and so on) by standard methods of polyurethane processing, as the presence of metal nanoparticles in their structure does not affect the physical properties of the polymer.

Resume : Determining the doping level is essential to optimize the properties of materials, e.g. luminescence. We present an original high-accuracy method based on the 31P solid-state NMR relaxation to determine low concentrations (< 1 %) of paramagnetic lanthanide ions. Our method was first applied to a model compound, LaPO4, within the doping incorporation is known. NMR experiments under static and MAS conditions reveal that the 31P relaxation time T1 is strongly affected by the presence of paramagnetic ions in the vicinity of the phosphorous nuclei. A linear variation of 1/T1 as a function of neodymium (Nd3+) or gadolinium (Gd3+) concentration is shown in the 0-10 at.% range for a homogeneous distribution of the doping ions in the matrix. Our method is compared to a classic one: the evolution of cell parameter. The electronic relaxation times of Gd3+ and Nd3+ have been evaluated by ESR measurements under saturation conditions. This allows us to provide a semi-quantitative interpretation of the nuclear 31P relaxation measurements. We generalize our method to other crystalline (xenotime, apatite) and amorphous materials (phosphorous glass) to understand which parameter (structure, length) could influence the relaxation time.

Resume : Energy management indicates that in the future the main source of electricity will be renewable energy sources. Constant interest of new cheap, efficient and ecological photovoltaics devices stimulates study of new semiconductor materials and structures. CIGS (CuGaxIn1-xSe2) is supposed to be good compound for solar cells. However the high prices of Ga and In cause that to seek to the different materials with similar properties, whose energy gap will have a value 1,2 ? 1,5 eV. Cu2ZnSnS4 (kesterite) is a semiconductor that corresponds with all these requirements. The formation of it was investigated by thermal analysis during studies on the reactivity of CuS, ZnS and SnS2. The products were studied using X-ray measurements, electron microprobe and Raman spectroscopy.

Resume : Substantial progress in flexible or stretchable electronics over the past decade has extensively impacted on various technologies such as wearable devices, displays, or automotive electronics for smart cars. An important challenge here is reliability of these deformable devices against thermal stress. Different coefficients of thermal expansion (CTE) between plastic substrates and the device components which include multiple inorganic layers of metals or ceramics induce thermal stress to the devices during fabrication processes or long-term operations with repetitions of thermal cyclic loading-unloading, lead to device failure and degrade their reliability. Here we report an unconventional approach to form photo-patternable, transparent cellulose nanofiber (CNF) hybrid films as flexible and stretchable substrates toward reliable devices, using simultaneous electrospinning and spraying. The electrospun polymeric backbones and sprayed cellulose nanofiber fillers enable the resulting hybrid structure to be patternable photolithographically as a negative photoresist, and stable thermally and mechanically, with presenting outstanding optical transparency (~ 89 %) and low CTE (< 10 ppm/K). We also formed stretchable, origami substrates using the CNF hybrid, which are composed of rigid support fixtures and elastomeric joints, exploiting the photo-patternability. Demonstrations of transparent organic light-emitting diodes and touch-screen panels on the hybrid film suggest a promise for next generation electronics.

Resume : Mechanical robustness, electrical and chemical reliabilities of devices against large deformations such as bending and stretching have become the key metrics for rapidly emerging wearable electronics. Metallic glasses (MGs) have high elastic limit, electrical conductivity, and corrosion resistance, which can be promising for applications in wearable electronics. However, their applications in wearable electronics or transparent electrodes have not been extensively explored so far. Here, we demonstrate stretchable and transparent electrodes using CuZr MGs in the form of nanotrough networks. MG nanotroughs are prepared by electrospinning and co-sputtering process, and they can be transferred to various desired substrates, including stretchable elastomeric substrates. The resulting MG nanotrough network is first utilized as a stretchable transparent electrode, presenting outstanding optoelectronic (sheet resistance of 3.8 Ω/sq at transmittance of 90%) and mechanical robustness (resistance change less than 30% up to a tensile strain of 70%) as well as excellent chemical stability against hot and humid environments (negligible degradation in performance for 240 h in 85% relative humidity and 85 °C). A stretchable and transparent heater based on the MG nanotrough network is also demonstrated with a wide operating temperature range (up to 180 °C) and excellent stretchability (up to 70% in the strain). The excellent mechanical robustness of these stretchable transparent electrode and heater is ascribed to the structural configuration (i.e., a nanotrough network) and inherent high elastic limit of MGs, as supported by experimental results and numerical analysis. We demonstrate their real-time operations on human skin as a wearable, transparent thermotherapy patch controlled wirelessly using a smartphone as well as a transparent defroster for an automobile side view mirrors, suggesting a promising strategy toward next-generation wearable electronics or automobile applications.

Resume : A lithium tantalate is recognized by their exceptional proprieties piezoelectric, pyroelectric, and ferroelectric and no linear optic. These properties are extremely sensitive to inserting metals elements. In this work, we are interesting to insertion the hexavalents elements as W6+ in LiTaO3 phase. The polycrystalline solid solutions Li1-xTa1-xWxO3 (0 ≤ x ≤ 0.25) has been synthesized at 800°C and investigated by using high-temperature XRD, neutrons powder diffraction RT, PSD, MET, MEB and UV spectroscopy. The ferroelectrics transitions had been observed by XR diffraction analysis for all studied phases. The refinement of neutrons diffraction reveals the types of non stoichiometric formulas. It has been demonstrated that the tungsten W6+ is certainty localized on the [Ta] site and probably present in tetrahedral sites for x=0.10 with occupancy rate not exceeding 1% in the accuracy limit of the used technic. In other hand, using laser diffraction spectroscopy (PSD), the particle sizes increase with varying W6+ concentration (1 to 50 µm) accompanied with reduction of original population of particles class LiTaO3. The UV spectroscopy technic gives the energy bandgap, the values are near 4.81 and 3.85 eV in LiTaO3 and Li0.90Ta0.90W0.10O3 respectively for example, indicating the tungsten can improve the light absorption due, probably, to photochromic tungsten effect.

Resume : Despite the presence of a rather high amount of impurity oxygen in their structure the materials demonstrate excellent superconducting properties, such as jc (~106 A/cm2 in 0-1 T at 20 K), upper critical fields, Bc2 (42.1 T at 0 K, 15 T at 22 K), and trapped magnetic fields (1.9 T at 20 K in a 10 mm thick sample of 30 mm in diameter). The presence of Ti (just in contact with the sample or by addition to the precursors) during synthesis can affect the distribution of the impurity oxygen and hydrogen in MgB2 thus influencing the superconducting characteristics and giving the possibility to increase the critical current density, jc (Birr, Bc2), reduce porosity and avoid cracking. Synthesis under 2 GPa – 30 MPa pressure allows the preparation of highly dense MgB2 with 50- 80 % connectivity and a shielding fraction of 75-100%. The materials are promising for the generation of high magnetic fields and fault current limiters. AC losses per cycle of around 0.75-1 J/cm3, were measured by using the transformer method while the power loss was about 200 W. The distribution of the impurity oxygen can be regulated by synthesis temperature and Ti addition. It affects jc of high pressure MgB2 to a high extend due to the formation of oxygen-enriched Mg-B-O nanolayers or nanoinclusions and higher magnesium borides MgBx (x>4). Oxygen is partly dissolved in the MgB2 matrix, as an Auger study revealed. The calculation of the density of states (DOS) of Mg(B1-xOx)2 showed that all compounds are conductors with a non-zero DOS at the Fermi level. For x0.25 the DOS is even somewhat higher than in pure MgB2 and the binding energy is similar. A high amount of H leads to porosity in MgB2 and MgH2 formation, which correlates with a jc decrease. The manufacturing of large (30-150 mm) crack-free samples under pressure is practically impossible without Ti. Its high affinity to H (higher than that of Mg) absorbs impurity H by forming TiH2.

Resume : Composite materials substitute more and more single component materials. Nanocomposites can have superior properties which originate from their huge interface area and small structure sizes. For instance, due to quantum confinement, the electronic bandgap of sponge-like silicon embedded in SiO2 is larger than that of bulk Si, and it can be even tuned by the fabrication process. Thus, due to the bandgap adjusted to the solar spectrum, such nanosilicon is a promising material for photovoltaics [APL103(2013)131911, APL103(2013)133106, APL103(2013)203103), NanoLetters16(2016)1942]. Furthermore, due to its huge capillary forces, a sponge-like nanoceramics can be used to immobilize efficiently high-temperature melts. This makes a nanoporous composite of chemically stable ceramics an interesting material for energy conversion and storage applications. Here, we present experimental studies and large-scale atomic computer simulations on the spinodal decomposition and the coarsening process of the nanostructure. It will be shown that the spinodal decomposition can occur by solid state processes as well as in the liquid state if the components are immiscible. Liquid-state decomposition is performed at a millisecond time scale using a diode laser scan. Although the liquid-state decomposition is about a million times faster than the solid state decomposition, the mean nanostructure length is about 10x higher.

Resume : CdS nanowires-polymer composite was prepared on a single carbon fibre. A carbon fibre with the resistivity of ~3.8*10 3 Ohm*cm, the diameter of ~5?10 ?m and the length of ~15?30 mm was served as the electrode. As the top electrode the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) has been drop-cast from the 1.3 wt.% water dispersion. Zinc phthalocyanine (ZnPc) or Poly(3-hexylthiophene) (P3HT) served as organic donor counterparts. The current-voltage characteristics (CVC) of following composites were investigated: (i) Solid-State Dye-Sensitized Solar Cell (SSDSSC); (ii) Electrochemical Dye-Sensitized Solar Cell (DSSC). It was found that behaviour of charge carriers in the SSDSSC structure obeys mainly the power-law dependence with ??=?2 that corresponds to the first-order (monomolecular) recombination with p?>>?n, that means that concentration of the injected minority charge carriers is not enough for effective transport in the structure. In the case of the DSSC structure, the charge carriers behaviour follows the cubic dependence with ??=?3. In both structures the interface of CdS nanowires with ZnPc-4R plays the main role in formation of photo-generated charge carriers. On the base of analysis of the CVC curves the suggestions for optimization of the composites for PV application can be formulated: (i) to decrease substantially the bulk resistance in SSDSSC and DSSC; (ii) to improve injection of both types of charge carriers from the contacts in case of SSDSSC; (iii) to use a tighter CdS layer around the CF electrode to escape shortcutting problems in SSPSSC and ISP composites and (iv) to replace the CdS layer for the p-type semiconductor. The possible application of investigated composites for solar cell is discussed. Financial support of CRDF project No. UKE2-7035-KV-11.

Resume : Complex 1D/2D nanowire structures based on AIII-BV compounds due to their unique physical-chemical and electrical properties are very attractive for micro-, nano- and optoelectronic applications including bio-electronic sensing [A. Naumov et al. (2016) J Appl Phys, in press]. We studied electric current-voltage (I-V) characteristics of gallium-nitride (GaN/AlGaN) transistor-type (HEMT) planar heterostructures (HS) with nanowires (NW) grown by MOCVD method on dielectric substrates (sapphire c-Al2O3) and fabricated by electron-beam lithography and laser ion-beam etching in a form of 600 nm long strips of different widths 185-1110 nm. Ohmic contacts were made by sputtering Ti / Al / Ni / Au nanolayers and annealing at 900 C. The conducting channel in quantum wells (QW) with a two-dimensional electron gas (2DEG) in the HEMT structure is near the gate surface and is extremely sensitive to the environment. NW elements add more surface area to increase the sensitivity required for the detection of biomarkers in bio-sensing at the atomic and molecular levels. Systematic optical and electrical measurements showed an excellent sensitivity of such NWs to micro- and nanodroplets of buffer solution with different index pH = 5-9. For the broad NWs (1110 nm) the ratio of output current to the sensor current at the gate is 1.3-1.5, for the narrow NWs (280 nm) this ratio is 1.36-1.32 (at voltages of ~ 2 V). For the finest NWs (185 nm) the current-voltage changes during incubation of droplets are hardly observed. The results obtained demonstrate the potential use of complex nanowire HEMT structures as bioelectronic sensors. Research is in progress. Support of the DAAD, BMBF and FP7 project FOTONIKA-LV at Latvian University is gratefully acknowledged.

Resume : Titanium-manganese mixed oxides, TiO2/MnOx (TMO) are one of the most remarkable functional materials in a family of metal-oxide semiconductors, which have enhanced photoactivity in response to light and capabilities of various energy and environmental applications including photovoltaics, photocatalysis and photosensors. We studied nanostructured TMO composites with different Mn content. High-purity TMO samples were synthesized by chemical precipitation of manganese hydroxide on the surface of TiO2 particles, followed by thermal treatment at different temperatures. The samples were characterized by XRD, FTIR, Raman, UV-VIS optical absorption and PL emission spectroscopy. According to XRD spectra, nanocrystalline TMO calcined at 300оС have Mn2O3 phase, while TMOs annealed at 900оС have the MnTiO3 phase. FT-Raman spectra revealed the existence of different transient MnOx crystal phases resulting transformations upon thermal treatment. FTIR spectra observed in the region of internal and lattice vibrations (400 800 cm-1) of TiO2, Mn2O3 and MnTiO3 suggest the existence of different oxidation levels and structural defects. UV-VIS absorption spectra show a significant shift of the absorption edge toward longer wavelengths, implying the reduction in the band gap as compared with pure TiO2. For TMO with Mn of 15at.% the Ea value is of 2.4 eV. PL spectra of TMO in its main features are similar to those of TiO2, but differ in their intensities. At high contents of Mn (above 8%), due to the increasing number of non-radiative recombination centers, the PL intensity is lower. These results demonstrate the potential use of TMO. Research is in progress. Support of the FP7 project FOTONIKA-LV at Latvian University is gratefully acknowledged.

Resume : Film-forming materials (FFМ) are used as initial substances for obtaining coatings by PVD (Physical Vapor Deposition) method more often. In a CVD (Chemical Vapor Deposition) method the coating is formed in a course of gaseous reactions between volatile components. Earlier we developed composite FFМ on the basis of system Ge-ZnS, evaporating congruently at rather low temperatures. Evaporation in vacuum and condensation on a substrate of such kind of material combines in itself the features of both PVD, and CVD processes. The calculated value of conditional temperature (Tc=TP≈1.33Pa) for composite named CVD - composite (590°С) is much lower, than for ZnS (820°C) and for Ge (1410°C). Thus, according to XRDA, the nano-composite type coating occurs though the initial material being microcrystalline. It makes possible to improve essentially optical and operational (especially, mechanical durability) parameters of coatings. In addition to their application as FFМ of new type, they are used, for example, in a finishing stage of a way of deep clearing of zinc sulfide from oxide admixture. Surplus of the sulfidizing agent, Sb2S3 is eliminated by processing with an additive of highly dispersed Ge. Other CVD-composites as FFМ on the basis of binary compounds are investigated also, namely: Ge-ZnSe, Ge-Sb2Se3, Ge-In2Se3, Ge-EuS, Ge-EuSe, Ge-ZnO, Ge-GeO2, etc. Considerable part of this series has shown high level of optical and operational parameters of coatings.

Resume : The ASTM F2792.15493231 standard is the definition of additive technologies: Additive Manufacturing - the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing technologies - the process of combining materials to create an object on the basis of data 3D- model, as a rule, layer by layer, in contrast to the «subtracting» production technology. In this definition, three key points: the compound material; Computer 3D-model; Unlike metal cutting machining technologies, which are defined as «subtractive» technology. Lamination with the definition used «as a rule», that is, may not be required. Thus, the compounds of technology components in disperse the finished product in the same process - by definition, are additive. Technology of powder metallurgy, which are used in industry for more than a hundred years, could reasonably be attributed to the industrial additive technologies. The grounds for such a statement as follows: - Raw material powder metallurgy - in disperse form; - Feedback on particulate feedstock pressure and temperature - the finished product 3-D finite size and shape; - Improving the powder properties of the product is achieved by increasing its density.

Resume : Poor compressibility of high-speed steels’ powders necessitates the use of additional operations at the technological conversion (Stamp-process: filling capsules with powder, evacuating and sealing, heating, isostatic compaction of capsules, forging or drop stamping). The appearance on the market of compressible atomized high speed steel M2 powder with low oxygen content at the expense of vacuum reduction has provided an opportunity to reduce the number of technological transitions. Various technological schemes of production of high speed steel based on M2 powder by hot forging of porous preforms were studied in this paper. In accordance with the first scheme cold-pressed preforms were hot forged. At the implementation of another scheme prior to forging preforms were sintered in a disassociated ammonia environment. Following hot forging heat treatment was carried out (quenching + tempering). These samples were mechanically tested in parallel with the witness samples made from cast steel. The optimal technological modes of hot forging, providing production of high density high-speed steel M2, the properties of which are level with the samples-witnesses, have been determined. The possibility was demonstrated to oxidize interparticle surfaces during sintering due to the presence of chromium in the composition of the initial powder. It is recommended to perform the sintering in a protective atmosphere with a low dew-point temperature or to exclude this operation from the manufacturing.

Resume : Realization of effect of Removal of an electric current allows to regulate process of carry of thermal and electric energy from a place of defeat of carbon-plastic by a lightning. This effect depends on a construction and properties of soldered knots of net. In many electro technical and electronic systems apply metallization and the soldering. Wetting of wire surface by solder at creation of a wire net construction has great value. The sessile drop method with ?capillary purification? method was applied. The wetting of compact materials on the base of pure copper and bronzes (tin, beryllium, aluminum) by the low temperature solders on the basis of tin was studied. Temperature dependences of a contact angle by free lead alloys have shown decrease of size of angles with growth of temperature. Beryllium bronze is wetted by alloys practically as pure copper. At wetting of bronzes Sn?Ag?Cu solder showed the better activity in comparison with alloys Sn, Sn?Pb, Sn?Bi. Results on wetting by O-2, SAC (Sn?3,2 % Ag?0,7 % Cu), CASTIN (Sn?2,5 % Ag?0,7 % Cu?0,5 % Sb) and Sn?Bi alloys of copper and bronzes substrates showed, that copper and beryllium bronze by alloys are wetted better. Sn?Ag?Cu solders, and also Sn/Bi alloys for metallization and soldering of high porous copper net construction were used.

Resume : The current state of development of powder metallurgy process characterized by continuous enrichment of getting new ideas penetrating porous materials (PPM). However, the solution to these problems of powder metallurgy limited, on the one side, technological capabilities of known techniques and methods for filtering materials [3, 4]and on the other, dependencies number of properties on the parameters of production. Moreover, in practice when creating penetrating porous materials with specified complex performance there are difficulties related to limited features traditional manufacturing techniques. So, to create practical PPM desired porous structure that will meet the optimal combination of performance, it is necessary to establish interconnection between technological regimes and obtain optimum pores distribution of radius by PPM. Method radial isostatic pressing is that unlike more common axial pressing in rigid matrices, the effort applied to the powder in the radial direction. One of the advantages of this method considered the uniformity of density distribution by volume pressing. Indeed, the cost of countering external friction when radial compressions, from this point of view, were an order of magnitude smaller. This fact and was the root cause when choosing a method of obtaining long hollow cylindrical products. Therefore, on the basis of the above, as well as special attention, this takes the matter due to the choice of compression technology. The purpose of this work is to carry out a special study aimed to address the issue of distribution of density in the radius the radially isostatic pressing. To achieve this goal were as the following tasks: • The description of the geometric model of the process of pressing PPM and calculate exertion and speed of deformation at the same; • To determine the field density hollow PPM; To achieve this goal applied continuum plasticity theory porous body in modification proposed . This will be the results, which have a relatively simple analytic view that allow analyzing the factors that contribute to the heterogeneity of distribution of density. The calculations and conducting practical research porosity change when the radius of the cylindrical blanks PPM (hollow cylinder), which is made by radial isostatic pressing. The authors of this research was the analysis and calculation of density distribution radius hollow PPM, which is obtained by radial isostatic pressing. During the theoretical calculations was the result, which has a simple analytical view and allows you to analyze factors that contribute to heterogeneity of distribution of density. This is shown in the course of calculations and experimental verification. Statistical analysis obtained during the measurement characteristics of PPM obtained and displayed graphic depends imaging analysis process structure.

Resume : This report focuses on the results of the EU project Superlight-weight thermal protection system for space application (LIGHT-TPS). The bottom line is an analysis of influence of the free space environment on the superlight-weight thermal protection system (TPS). This report focuses on new methods that based on the following models: synergetic, physical, and computational. This report concentrates on four approaches. The first concerns the syner- getic approach. The synergetic approach to the solution of problems of self-controlled synthesis of structures and creation of self-organizing technologies is considered in connection with the super-problem of creation of materials with new functional properties. Synergetics methods and mathematical design are considered according to actual problems of material science. The second approach describes how the optimization methods can be used to determine material microstructures with optimized or targeted properties. This technique enables one to find un- expected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The third approach concerns the dynamic probabilistic risk analysis of TPS l elements with complex characterizations for damages using a physical model of TPS system and a predictable level of ionizing radiation and space weather. Focusing is given mainly on the TPS model, mathematical models for dynamic probabilistic risk assessment and software for the modeling and prediction of the influence of the free space environment. The probabilistic risk assessment method for TPS is presented considering some deterministic and stochastic factors. The last approach concerns results of experimental research of the temperature distribution on the sur- face of the honeycomb sandwich panel size 150 150 20 mm at the di?usion welding in vacuum are considered. An equipment, which provides alignment of temperature fields in a product for the formation of equal strength of welded joints is considered. Many tasks in computational materials science can be posed as optimization problems. This technique enables one to find unexpected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The last approach is concerned with the generation of realizations of materials with specified but limited microstructural information: an intriguing inverse problem of both fundamental and practical importance. Computational models based upon the theories of molecular dynamics or quantum mechanics would enable the prediction and modification of fundamental materials properties. This problem is solved using deterministic and stochastic optimization techniques. The main optimization approaches in the frame of the EU project ?Superlight-weight thermal protection system for space application? are discussed. Optimization approach to the alloys for obtaining materials with required properties using modeling techniques and experimental data will be also considered. Acknowledgements.This work has received funding from the EU FP7 Project “Super Light-Weight Thermal Protection System For Space Application" (LIGHT-TPS) under Grant Agreement no. 607182

Resume : Due to specific interatomic interactions based on complex electron exchange of 2s22p boron atom and 2s22p2 carbon atom, as well as due to development of the complex crystalline structure, boron carbide demonstrates a unique combination of attractive properties, offering potential for wide-ranging advanced applications. High hardness (45 GPa), high E modulus (450-470 GPa), high melting point (2450 оС), lesser density (2.52 g/cm3) are driving current interest in В4С. In addition to the conventional В4С applications in abrasives, boron carbide currently is a popular choice for nuclear energy applications such as control rods and radiation protection, as well as for development of wear-resistant structural and impact-tough ceramics for various applications . At the moment the reaction-bonded boron carbide (RBBC) ceramics sees active development. RBBC is a lightweight composite that comprises many phases, such as silicon (Si), silicon carbide (SiC), complex boron carbide-based carbide phase (B4-хSiyC) and boron carbide (B4C). RBBC is typically processed via silicon melt infiltration into a porous preform at 1450-1650 ºС. Despite lower hardness and wear resistance of RBBC, as compared to the hot-pressed boron carbide (HPBC), the former material offers much more attractive price and a number of other advantages provided by the reaction bonding processing technique. Virial LTD. company has implemented a production of boron carbide parts with max. OD up to Ø300 mm by hot pressing (proThese investigations have been allowed to understand the relation between the processing parameters and the properties of the final RBBC composite has been understood. The choice of premix composition and acceptable time-temperature tolerances when implementing the process in a large industrial-scale reactors have been substantiated.