Composite materials and structures: from research and practical demands to application

Resume : In present report a new type of the nanostructurated material, amorphous SiC enriched with carbon nanoclusters, is considered. Surface morphology, chemical composition and electronic properties such a-SiC layers deposited by magnetron sputtering method on n-type Si substrate are described. It was shown that the a-SiC layer deposited by such manner at low temperature was nanostructurated porous material with diameters of porous channels about 5-10 nm (in dependence on technological regime) which oriented perpendicular to surface. To fabricate electron emitting material the a-SiC/Si structures were subjected by high-temperature vacuum annealing at 900 and 1000?C for 30 minutes that resulted in amorphous carbon nanoclusters segregation into the channels of the porous a-SiC. This effect was studied by STEM technique equipped with electron energy loss spectrometer, micro-Raman spectroscopy and electrical measurements. After high-temperature annealing the isolating a-SiC film with low resistivity was transformed into high resistivity material with metallic conductivity. Electron emission from the a-SiC/Si structures was studied in dependence on carbon concentration and a-SiC structure. The mechanisms of charge transport in such structures are discussed.

Resume : Advanced ceramic materials due to their high thermal resistance, hardness and other unique properties are used in variety industries. The key stages in the fabrication of ceramics are shaping of powders and sintering. Shaping of ceramics puts today’s science and technology high requirements, above all the ability to produce ceramic components with complex geometries, minimized final machining with the use of expensive tools and the application of environmentally friendly processing agents. The main challenge in colloidal shaping is to develop a homogeneous and stable ceramic suspension having low viscosity and high concentration of ceramic powder at the same time. Authors examined the properties of ceramic materials based on α-Al2O3 and ZrO2 obtained by using colloidal processing with the use of functional monomers. Monomers contained hydroxyl and vinyl groups in a molecule and therefore could polymerize in the colloidal suspension in aqueous environment. The properties of pure organic additives have been measured, such as polymeric shrinkage and glass transition temperature. Then the influence of type and amount of additives on the properties of ceramic colloidal suspensions and resulting materials in a green and sintered state were examined. As final products zirconia tapes and alumina samples of high density have been obtained. The project has been financially supported by the Warsaw University of Technology, Faculty of Chemistry.

Resume : Shear-thickening fluids are concentrated colloidal suspensions characterized by increase in viscosity with an increase in shear rate or applied stress. It was shown that under the influence of impact, the rheological behaviour of the dilatant material changes from that of a liquid to behaviour characteristic for solids . Slurries with such properties are potentially interesting for certain industries. Shear thickening fluids due to ability to rapid response by place resistance to operative force potentially find application in such fields where there is a necessity to dampen and disperse energy. The examples are: ski boot cushioning, dampers, rotary speed limiters, liquid couplings, shock absorber fillings. Lot of interest is also focused on so called ”liquid armors”. The great advantage of body armor based on shear thickening fluid is that it is lightweight and flexible, because consist of only from 2 to 6 layers of Kevlar. Furthermore, can protect the whole body, which in the case of traditional vest is impossible. In this work authors present results concerning on preparation and energy absorption of shear thickening fluids. This work was supported by the National Center for Research and Development (agreement No. PBS1/A5/19/2012).

Resume : Composite materials based on refractory nitrides have been obtained by the method of low-temperature nitriding of precursors preliminarily mechanoactivated in a planetary mill. In the choice of precursors (TiSi2, B4Si, VSi2, and CrSi2 silicides and AlB2 boride), the main idea consisted in comparing their thermodynamic stability with the stability of nitriding products and decreasing the temperature of nitride formation due to activation of precursors. The used method provides the homogeneous distribution of phase components in synthesized powders and the homogeneity of structural transformation in their subsequent hot pressing. Hot-pressed materials obtained from the synthesized composite powders have increased mechanical characteristics.

Resume : The morphological evolution of hybrid organic-inorganic structures during chemical bath deposition onto Si patterned substrate has been investigated. Aqueous solutions of organic heterocyclic chlorine derivation were used for room temperature chemical deposition. For structure formation the following organics were used: clonidine hydrochloride, procainamide hydrochloride, thiamine diphosphide, amiodarone hydrochloride, metamizole sodium and sulfacyl sodium. Due to morphological features of anisotropically etched pyramid substrate the facet {111} of pyramid is a vicinal surface. It contains quasiperiodic flat low-Miller index terraces, which are separated by steps with kinks (TSK mechanism). Under morphological stability condition (stable facet growth) the surface mediated heteroepitaxial growth takes place, i.e. the TSK growth model is realized. The hybrids developed have been used for photovoltaic application. As the result the efficiency of 8.00 % under 60 W/cm 2 has been achieved. It has been found that there are the qualitative and quantitative correlation of morphology of hybrids grown with PV parameters and their dependence from irradiance energy. The chemical bath deposition of the pharmaceutical organic materials can be used for barrier formation on Si. This barrier could be attributed to bandgap or surface state associated with hybrid non-stoichiometric interface including halogen excess or deficit (chlorine) in certain cases. Financial support of Sensor National Pro

Resume : Dipole moment, polarizability, and first-order hyperpolarizability of polyphenyl derivatives have been investigated using ab initio and density functional theory calculations. Geometries of all molecules were optimized at the Hartree–Fock and DFT levels in a series of steps, first with the 6-31G(d) and 6-31+G(d) basis set, then with the 6-311G(d) and 6-311+G(d) basis set. The dipole moment , polarizabilities and The first static hyperpolarizabilities of these molecules were calculated using HF and DFT levels using same basis sets using GAUSSIAN 03 W. In general, the first hyperpolarizability is dependent on the choice of method and basis set. In order to understand this phenomenon in the context of molecular orbital picture, we examined the molecular HOMOs and molecular LUMOs generated via HF and DFT/6-311+G(d) level. The study reveals that the polyphenyl derivatives have large β values hence in general may have potential applications in the development of non-linear optical materials.

Resume : UV absorbing composites are of interest for a variety of applications including Circuit breakers, UV-shielding windows, contact lenses, or glasses among others. Such materials can be made by incorporating suitable UV-absorbing materials into a polymeric matrix. In this work cupric oxide (CuO) nanoparticles have been synthesised and used to change the properties of a polymer matrix in order to improve the ultra-violet (UV) absorption property of the polymer. The synthesis of CuO nanoparticles, UV absorption property and the dispersed concentration of CuO nanoparticles in polyethylene (PE; [–C2H4–]n) were investigated. The results showed that the UV absorption increased significantly by increasing the dispersed concentration of CuO nanoparticles. The UV absorption edges were evaluated from the UV-Vis absorption spectra by using Cary 100 Bio UV-Visible Spectrophotometer. The dispersion of nanoparticles in the polymer matrix were characterised by Transmission electron microscopy and Fourier Transform Infrared Spectroscopy techniques. The synthetic process used as well as the characteristics of the resultant composite material will be presented in detail. Keywords: Polymer Nano-composites; cupric oxide; UV-absorption; nanotechnology

Resume : Often for braze together ceramics and other nonmetallic materials with metals, non-metallic surfaces have to be covered by a variety of metals, in particular, by chromium and nickel, in the form of thin films. In this paper the dispersion and coagulation kinetics of chromium and nickel nanofilms 100 nm thick have been deposited onto oxide materials (alumina ceramics, sapphire, quartz glass) and have been annealed in vacuum at temperatures 1000 - 1200 oC with endurance at each temperature from 2 up to 20 min. Initial films of both metals onto all substrates were continuous and practically kept the continuity at annealing temperatures up to 1000 oC. After long endurance (20 min) at 1000 oC the films onto all substrates start to break up. This process is intensified at 1100 oC and after annealing at 1200 oC the films of both metals completely break up to separate fragments and drops. Using the received results it is possible to recommend application of chromic and nickel coating for the subsequent brazing at the temperatures which are not exceeding 1100oC taking into account that at these temperatures there is no yet take place full films disintegration and the area of nonmetallic substrates surface has been coated by metal films consisted 60 - 70 % of the initial substrates area. At the same time article brazing time at temperature 1100 oC should not exceed 10 min.

Resume : The present work aims to investigate the details of phenomena for wettability, adhesion, and contact interaction intensity of tin dioxide ceramics with Ag-Cu-O alloys at 1200-1300 K by the sessile drop method. The dependence of the contact angle for the tin dioxide ceramics by Ag-Cu-O melt in air eviroment on the concentration of copper was obtained. It was shown that the addition of copper in molten silver decreases the contact angle in the system. Analysis of the ceramics/alloy interface shows the presence of transitive zone, which is an obvious result of copper diffusion into the ceramic substrate.

Resume : The development of composite materials in the “intermetallic-refractory compound” systems is one of the up-to-date trends in designing of novel materials aimed at operating under conditions of significant loads at high temperatures. In this work, as a matrix for such a composite materials, nickel aluminide (NiAl) was selected which is widely used as protective coatings on the aerospace engineering parts. To be used under conditions of intense wear in a broad temperature range (to 1000°C), intermetallics require dispersion strengthening with the hard refractory inclusions. The TiB2, CrB2 and ZrB2 were chosen as strengthening components for NiAl in view of its high hardness and wear resistance. The NiAl-Ti (Cr, Zr) B2 composites are aimed at operating in high temperature friction assemblies. Therefore, processes running during performance of the developed materials at high temperatures are of considerable scientific interest. The effect of oxidation at T=1000°С of the NiAl-Ti (Cr, Zr) B2 composites in air on the structure, phase composition and intensity of formation of oxide layers on the composites surfaces has been studied. By the oxidation of the composites selective oxidation was observed. To determine the relationship between the thicknesses of the oxides formed after oxidation, Auger-analysis was used. Therefore the intensity of oxide formation on boride grains is 3-7 times higher than that on the NiAl matrix. The established regularities of the oxidation of NiAl-Ti (Cr, Zr) B2 materials will make it possible to control mechanisms of tribosynthesis of intermediate antifriction oxide phases which are formed under friction and, thus, to achieve the high tribotechnical characteristics of composite materials and coatings.

Resume : It is possible to model of gravity change action on wettability in terrestrial conditions by change of drop volume and definition of a wetting contact angle for each value of this volume. Experiments for several high-temperature and low temperature systems namely water–paraffin, glycerin–sapphire, Au–quartz etc. have been carried out. In these experiments the wetting contact angle was measured for drops of the different sizes (volumes). For experiments with low temperature contact systems the special photooptical equipment in which the opportunity of continuous change of drop volume with the help of the dosing device has been developed. For the melted metals the available vacuum high-temperature equipment was used. Melted metal drops of various volumes were obtained by setting onto solid surface of the weighed metals. These data testified that in depending on drops volumes in an interval 0,01 up to 2–3 sm3 the wetting contact angle practically did not varied (regularly), at least within the limits of the mistakes of experiment caused by the physics-chemical reasons (some heterogeneity of wetted surface, hysteretic phenomena etc.). These mistakes for different systems are 1–3°. The greater disorder for wetting contact angle values is marked for especially small sizes drops. The general conclusion which can be made on the basis of the experiences carried out on the Earth is following: the wetting contact angle of solid surface by liquid does not depend on gravity value.

Resume : The equipment construction and different brazing technologies of multi-seams metal-ceramic assemblies for fabrication of special device for using in space conditions were developed. Aluminia ceramic rings were joined to covar details. Silver-copper filler with titanium additions was used for brazing of such metal-ceramic assemblies. Every assemblies as a complex products contains two blocks. There are eight brazed seams in every block. Technology elaborated allows to realize the precision (possessing the high accuracy of metal details fit) brazing of five or more seams at the same time at temperature of 850 – 950 °C. Wherein vacuum have to be not better than 0.002 Pa. Obtained in such method the model precision assemblies were tested for the high vacuum tightness and thermal resistance.

Resume : The effect of silicon (2 and 5 wt. %) introduced in composition of bioceramics based on biogenic hydroxyapatite using methylsilicic acid hydrogel with the following heat treatment at 600 °C on solubility in vitro and drug desorption (Rifampicin) from the surface of powders and porous samples was investigated. It was established that introduction of silicon in ceramics composition in the amount up to 5 wt. % decreases the pH and 7 times increases the solubility in saline. The desorption level of Rifampicin of Si-modified ceramics is higher due to the specific surface area (59.8 m2/g) that is 10 times higher that the specific surface area of “pure” ceramics. IR spectra confirmed the joining of Rifampicin to the ceramics surface. Adsorption and desorption of the antibiotic is better when porous samples were used in comparison to powders. It can be attributed to the developed porous structure (43-62 %) of the samples of bioceramics. Thus prepared Si-modified ceramics based on biogenic hydroxyapatite can be promising in orthopedics and traumatology for filling bone cavities and improving bone tissue regeneration using drug delivery.

Resume : Improving the strength and ductility of iron aluminide is possible due to grinding grain. Mechanical and performance properties can also be improved through the creation of composites with refractory intermetallic particles sized up to 10 microns. As a hardener for intermetallic matrix the compound has good recommendations TiB2. Application for hot forging of intermetallic Fe3Al and Fe3Al-TiB2 composites with high strength characteristics was the aim of this study. Hot forging allows to receive samples with a porosity of 7.5% for the alloy Fe-15Al and 3.5% for Fe-15Al-4TiB2. High residual porosity of intermetallic Fe-15Al may be related with the complexity of the deformation of flat and thin flake particles, which were formed after intensive grinding. In the case of co-grinding particles of Fe, Al and TiB2 occurs less active deformation of plastic particles, but there are difficulties in the uniform distribution of particulate matter throughout the volume milled powder. Despite these structural defects produced by forging their strength properties of the materials were at a high enough level (Fe?15Al ? K1c=19.5 MPa*m^0.5, TRS=1211MPa; Fe?15Al?2TiB2 ? K1c=19.3 MPa*m^0.5, TRS=1328MPa; Fe?15Al?4TiB2 ? K1c=17.3 MPa*m^0.5, TRS=940MPa). Subsequent optimization of the hot forging technology based on intermetallic alloys aiming at uniform distribution of particulate matter throughout the volume of the matrix will increase the strength properties of such composites.

Resume : Ceramic materials based on lead niobate-zirconate-titanate (PNZT) are electroceramics which has specific piezoelectric properties. Investigation of wetting by liquid metals and adhesive processes in ceramics/metal systems are very important parameters for application of such materials. Thus, the research of wetting PNZT by alloys Ag–Cu–O in air gaseous media was carried out in present work. Based obtained data, the braze composition and metal-oxygen technologies for brazed joints PNZT ceramics in air and pure oxygen atmosphere were developed. Also a method of metallization with high adhesion of coating on the piezoelectric ceramic surfaces using metal melts containing oxygen was elaborated.

Resume : NASICON-structure Na3V2(PO4)3 has been studied for its high Na ion conductivity. However, its low electronic conductivity limits its electrochemical performances. Even though carbon coating would beneficial to enhance its electronic conductivity, carbon coated layer may hindered the migration of Na ion between electrode and electrolytes. The Na3V2(PO4)3-carbon nanofibers composites prepared by electrospinning method followed by thermal treatment has special morphological characteristics that nano-size Na3V2(PO4)3 partly embedded in carbon nanofibers. Carbon nanofibers provide fast electron delivery pathway and exposed Na3V2(PO4)3 without carbon layer contact with electrolytes directly. With benefits from the morphological characteristics, as cathodes for sodium ion battery, the NVP-CNF shows capacity of 112.5 mAh/g, 79% maintained capacity at 50C and 97% of cycle retention after 100 cycle at 1C.

Resume : Now in technics ceramic materials on aluminina and zirconia basis which capable long to work on air at high temperatures are used. Frequently there is a necessity to receive high-temperature joints of these materials with application of metal gaskets or solders. The solders suitable to creation of such joints can be only platinum group materials which are steady against influence of oxygen at high temperatures and the most effective method of these joints fabrication is pressure welding. In the given work opportunity of ceramics on basis Al2O3 and ZrO2 joints fabrication by pressure welding using rhodium and iridium gaskets have been investigated. Surfaces of ceramic samples having size 15 x 15 x 10 mm which must be joined by pressure welding have been grinded and then have been polished up to mirror shine using diamond powders. After mechanical processing the samples have been degreased by acetone and spirit and them they have been annealed on air at temperature 1200 oC. After annealing the samples have been joined in pairs through rhodium and iridium wire of 0,5 mm in diameter. The joining regime was the following: the temperature was 1650 oC, pressure - 15 МPа, endurance consists of 10 min in vacuum which is not worse 2 x 10-3 Pа. The fabricated joints have been tested for shift and have shown durability 120 MPа at temperature 20 oC. The given joints can be exploited at temperature 1800 - 1900 oC on air.

Resume : The purpose of the present work is to study the electrochemical behavior of zirconium in the KCl–NaCl–NaF–K2ZrF6 melt, its reduction jointly with the boron complexes, the way that zirconium diboride is synthesized, and to estimate the possibility of its high-temperature electrometallurgical production. The following were found: (1) In the KCl–NaCl–NaF–K2ZrF6 melt, the zirconium (IV) ions are present in the form of mixed chloride–fluoride or fluoride complexes, depending on the concentration of the fluoride ion. (2) The electrochemical reduction of zirconium, depending on the concentration of the fluoride ion, proceeds according to the scheme of auto-inhibition or with the four-electron reversible one-stage transfer. (3) The electrochemical synthesis of zirconium diboride is preceded by the reaction of the formation of the combined zirconium (IV) and boron (III) complexes limiting the electrode process. (4) The stage of the charge transfer at the reduction of the combined complex in the wide interval of the polarization velocities proceeds reversibly with the one-stage transfer of 10 electrons. (5) The compositions of electrolytes and the electrolysis regimes for the practical implementation of the high-temperature electrochemical synthesis of zirconium diboride powders and coatings are determined.

Resume : Wetting and spreading kinetics of liquids over solid surfaces for model systems with physical type of interaction: water, ethanol, glycerine-glass, quartz, sapphire and movement of the interphase of two immiscible liquids (oil-water) along solid surfaces (glass, plastic) were studied using video filming. The results are compared with data obtained earlier for high-temperature systems with chemical interaction and some possible practical applications of similar systems are considered, in paticular for purification of liquids or solutions from oil emulsions or gas bubbles by way of a selection of solid components contacting given liquids with appropriate wettability.

Resume : Thin films of metals on non-metal materials surface show a tendency to congregate in separate islands at heating. The process depends on surface tension of film and on adhesion of metal to substrate. Zirconia can loose the oxygen with non-stoichiometric phases formation, whrein adhesion of metals to the non-stoichiometric zirconia is higher than to stoichiometric. The influence of zirconia stoichiometry on behavior of the platinum and the palladium thin films, applied on it surface, at vacuum heating was investigated. It was founded that on stoichiometric ZrO2 noble metals thin films congregates in islands at temperatures significantly lower than temperatures of metals melts. In non-stoichiometric zirconia case film retains continuous, although transforms, probably the formation of new phases due to interaction of noble metal to zirconium from substrate takes place.

Resume : Technologies of composite coatings which join different phases and provide new properties, including high biocompatibility are intensively developed. The idea to create composite coatings (CC) in which carbon nanotubs (CNT) as strengthening components and biocompatible apatite-similar compounds as the matrix which fills space between CNT is offered. CC created for artificial limbs manufacturing have high biocompatibility but low level of mechanical properties. Owing to specific electronic connections in these compounds low durability, high fragility, low tribotechnical characteristics (which are important for manufacturing of joints) is observed. Today the most perspective approach is to use of CC put on a constructive material with high mechanical and other properties. It is possible to put CC on bearing basis to form high tribotechnical surface properties with high biocompatibility. To create such CC there are some problems to be optimized: structures, interaction on CNT and apatite-similar matrix interface, cohesion and adhesion connections. It is offered to solve these problems by creation of CC on a surface of an intermediate chemically inert substance layer. Such layer is put on a surface of bearing titanic alloy construction. Cultivation of CNT on this layer and space filling between them with a matrix is the following step. Thus, composite system of an artificial limb with necessary level of mechanical properties and biocompatibility is formed. Financial support: MESU project №2510f “Formation of functional and biocompatible composite coatings on titanium and iron alloys, with carbon nanotubes”.

Resume : New multifunctional material design is an important task of advanced material science. But in many cases to improve the reliability and durability it is sufficient to improve physical-mechanical working surfaces properties. Electric-spark alloying (ESA) is an effective method of surface hardening and can reduce a cost of metal materials applied. Regularities of structural phase transitions and formation of properties (microhardness and wear resistance) of coatings obtained by ESA of surface of low carbon steel in complex saturating medias contained transition metals (Zr, Ti, Cr) were investigated. A number of medias chemical composition changes during the ESA lead to formation of multi-component functional coatings. Microhardness of steel surface layers is increased up to 10 GPa, and wear resistance increases by 8 times compared with initial state (without treatment) due to intrusion phases, formed by interaction of metal anodes (Zr, Ti, Cr) with medium elements (N, C, O) under conditions of ultrafast steel local volumes heating and cooling, concentration and temperature gradients, presence. Correct choice, optimal combination of medias, the number and sequence of processing steps allow targeted control the structure and coatings properties and provide high repeatability production. Financial support: by MESU project №2510f “Formation of functional and biocompatible composite coatings on titanium and iron alloys, with carbon nanotubes and strengthened by interstitial elements under extreme energy treatments”.

Resume : Results of: imitation modeling of high gradient temperature fields in a laser treated surface zone of Fe with Cr (up to1.91 vol.%) and Ti (up to 1.05 vol.%); effect of temperature fields in near-surface layers under laser alloying of Fe-alloys from solid and pasty coatings on mass transfer and structure formation; models of diffusional structure formation in near-surface volumes due to interaction of laser radiation with surface in solid and pasty coatings presence; prospects of technologies proposed for industrial use, – are presented. We propose the generalized scheme of laser alloying zone of Fe-alloys with carbide-forming elements structure. This scheme is based on four models depending on physical and technological parameters: 1) when coatings thickness is ТіС h≤10 μm and power density Wp~5 GW/m2 discrete-heterogeneous near-surface layer structure based on supersaturated solid solutions and dislocations accumulation with secretions of Ti dispersed carbides on them are being formed; 2) when ТіС coating thickness increasing is 10

Resume : We have studied and suggested: regularities of an influence of preliminary chemical and heat treatment together with laser irradiation of surface on mass transfer and diffusional discrete-inhomogeneous structures formation in near-surface volumes of Fe-alloys with Ti (up to 1.05 vol.%) and Cr (up to 1.91 vol.%); multistage model of nitrogen re-distribution during of laser irradiation of nitrated layer; technical and technological results that demonstrate prospects of technologies suggested for industrial application. The model of stage-by-stage nitrogen re-distribution during laser treatment of nitrated layer (as an example – for Fe + 0.7 wt. % Ті alloy) consists of: – matter's liquid state formation and nitride phases layers (+) dissolution; – nitrogen diffusion from liquid phase into solid phase; – over-saturated solid solutions formation and its quenching; – discrete-inhomogeneous structure with dispersed nitrides particles formation. Combined surface treatment (CST) – preliminary nitration and subsequent laser treatment – leads to increase of laser treated material microhardness up to 6-8 GPa (Fe+0.7 wt. % Ті) and 6,5 GPa (Fe+1.5 wt. % Cr) in comparison with microhardness of material in diffusion zone after only of nitration – 5,8 GPa (Fe+0.7 wt. % Ті) and 5 GPa (Fe+1.5 wt. % Cr). Diffusion coefficients of nitrogen in the case of CST of Fe+0.7 wt. % Ті alloy are of 2-3 orders higher than typical values in tradition chemical and thermal treatments. CST of Fe+0,7 wt. % Ті alloy leads to wear resistance increasing in 3 times comparing with wear resistance of nitrated layer due to dissolution of brittle nitride phases (ε+γ′) layers and surface enrichment with nitrogen. These technologies can be applied for treatment of units being exploited under significant contact loadings. Another combined treatment (preliminary surface laser treatment and subsequent nitration) leads to near-surface area microhardness increase up to 6 GPa (Fe+0.7 wt. % Ті alloy) and up to 5.5 GPa (Fe+1.5 wt. % Cr alloy) caused by nitride phases (ε+γ′) on a surface and nitrated layer in an area of laser treated surface formation. Financial support: by MESU project №2510f “Formation of functional and biocompatible composite coatings on titanium and iron alloys, with carbon nanotubes and strengthened by interstitial elements under extreme energy treatments”.

Resume : Microstructure, microhardness and phase composition of near-surface zone of laser action in Fe-alloys with Cr (1.11÷1.91 vol.%) and Ti (0.7÷1.05 vol.%) were studied. It was shown that processes developed on outer surface of micron and sub-micron layers determine thermodynamically diffusion mass transport patterns in a volume (and thus serve as an additional – to concentration gradient – a driving force for mass transport in volume of material to outer surface). These regularities have evidences of superposition of structural-concentration and concentration-phase redistribution as results of mismatch in time of dominant mechanisms of diffusion mass transfer (diffusion by boundaries, diffusion in volume, surface diffusion etc.) with "distortion" – as a result of dimension thickness factors, fast changing gradients of concentrations, temperatures, mechanical stresses – the balance of those driving forces ideas of which historically formed. Therefore in such systems concentration gradients do not disappear, homogeneous concentration distributions are not achieved (even if the interacting components in a massive state have a unlimited mutual solubility). Similar effects are confirmed not only under traditional heat treatments and in conditions of extreme energy impacts which laser action on surface is but also in thin film multilayers and in quasi-crystalline compositions. That is this effect has a general character. The laboratory technologies based on results presented are ready for industrial applications. Financial support: by MESU project №2510f “Formation of functional and biocompatible composite coatings on titanium and iron alloys, with carbon nanotubes and strengthened by interstitial elements under extreme energy treatments”.

Resume : Recently, one of the most widely investigated nanomaterial is nanostructured magnetite. It is due to simple synthetic procedure and the fact, that Fe oxide is considered as relatively low toxic compound to living organisms. Therefore application starts in medicine, bacterial or fungal protection, technical application, electronic devices. Modification of the magnetite with noble metal shells (e.g. Ag, Au, Cu) causes change of the magnetic properties of the core. This way obtained new material can exhibit properties typical either for the magnetic core, and the metallic shell. Coexistence of the different characteristics in one spices allows for novel solution of the application of core-shell nanoparticles in medicine, food storage or wastewater filters. Obtained nanoparticles can be next connected to the third particle like fullerene, nanotube etc. via adequate linkers. Such hierarchical construction can bring new properties to the resultant nanocomposite. Popular are linkers based on –SH, –CN, or -COOH groups, because of its significant affinity to Au, Ag, Pt or metal oxides. In the presentation, we would like to describe how properties of the magnetic core changes due to presence of different noble metal surface layer. Modification of the particle core will be done by noble metals. Surface functionalization will be discussed on thiols as an example. XRD, TEM and IR spectroscopy gives structural characterization. Magnetic properties will be tested by Mössbauer spectroscopy.

Resume : The shielding properties of the epoxy composites (CMs) with carbon filler (graphite nanoplatelets (GNPs) or carbon nanotubes (CNTs)) and barium hexaferrite BaFe12O19 (BaM) were investigated. The content of carbon nanofiller in such composites was 5 and 10 wt.%, while the content of BaM was ~ 27 wt.%. Magnetic BaM particles are hexagonal with thickness of 35, 60 nm and diameter of 100, 250 and 400 nm. The study of electromagnetic characteristics in the frequency range 26.5-53.5 GHz showed that in composite with only BaM as filler due to the effective magnetic anisotropy the natural ferromagnetic resonance (NFMR) at a frequency of 46 GHz is observed. Adding of conductive nanoscaled CNTs or GNPs in these composites suppresses the resonance EMR absorption peak and leads to increase of both absorption and reflection of electromagnetic radiation due to introduced in the composite charge carriers interacting with electromagnetic radiation. It also was shown that the relative dielectric permittivity increased with content of carbon fillers and is equal to 25 for CMs with 10wt.% of CNTs and slightly depends on the EMR frequency in the range of 26.5-37.5 GHz.

Resume : Tungsten carbide hard alloys is of interest to various applications owing to fortunate combination of high melting temperature, high hardness, low friction coefficient and chemical resistance to corrosion and oxidation. The use of spark plasma sintering (SPS) is very suitable to be applied to prepare the materials with high density and nano- or fine-grained structure. The main idea of the SPS method consists in high-speed heating of powder materials by passing high-powered pulsed Dc through the die and sample and at the same time pressed. Owing to rapid heating rates, the powder sample can be consolidated at relatively lower temperatures and, moreover, the grain growth during sintering can be effectively avoided. The aim of this work is to investigate an impact of WC-Co nanopowders with different composition on the density, structure and mechanical properties of samples consolidated by SPS.

Resume : Research and development of new nanostructuring materials for engineering of nanoplasmonic and nanophotonic structures is perspective direction of material science. Low-temperature solid-phase interaction in a simple eutectic pairs of metal- semiconductor thin films is one of the ways to create such materials. Such eutectic pairs of films are used for recording media and could be used for creation of the most sensitive optical sensors and photonic crystals. Two-component systems of semiconductors and metals forming simple eutectic pairs was investigated. The solid-state interactions on the interface of systems metal-metal or metal-semiconductor are discussed. The results of the laser and thermal annealing are represented. Transmission spectra of binary mixtures Ge-metals measured in situ during the annealing demonstrate changes as a function of the annealing temperature. Change in reflection index spectra is demonstrated. The possibility to obtain the given curves of surface plasmon resonance (angular dependence of the intensity of the internal reflection R (Ѳ) surface plasmon resonance) and the shifts of this curves as the X-axis and Y-axis during annealing is shown. The advantage of these materials (low-energy interactions, long lifetime and environmental) make them promising for neoteric technology.

Resume : The aim of this study was to investigate the influence of surface roughness on the wear resistance of boride coating obtained by diffusion saturation of boron adding to the medium powder to saturation Cu2O, Cu3P or Cu. With this method saturation formed boride layers with separate inclusions of copper over the cross section of the boride layer Wear resistance coatings after saturation with boron and copper under dry friction – sliding on the air is 2 times better wear resistance than the boride coating without complex saturation. At all stages of wear lowest rate found in the response of boride layers obtained by the introduction of the medium for saturation Cu2O powder. This is due to the fact that the boride layers structure separate impregnations of copper detected that serve as solid lubricant. While the microhardness of boride phases FeB was 18.5 GPa and phase Fe2B – 14,5 GPa at saturation copper microhardness was decreased and for the phase (Fe, Cu)B – 15,5 GPa and for the phase (Fe, Cu)2B – 14,5 GPa. It was established that the smallest surface roughness (Ra = 0,158 μm) have boride coatings produced when introduced into the medium to saturate the powder Cu2O, and greatest (Ra = 0,899 μm) – complex boride coating without saturation. These results correlate with the data fully durability boride layers in determining the weight loss for certain periods of wear. Thus rows boride coatings obtained in various growth media saturating durability and reduction of surface roughness are the same. These rows can be represented as follows: FeB, Fe2B (medium at saturation B4C) → (Fe, Сu)B, (Fe, Сu)2B (medium B4C + powder Cu) → (Fe, Сu)B, (Fe, Сu)2B (medium B4C + powder Cu3P) → (Fe, Сu)B, (Fe, Сu)2B (medium B4C + powder Cu2O).

Resume : Tungsten and alloys on its basis thanks to the unique characteristics, finds more and more wide application in many branches of industrial production. Thus the most actual is creation of porous tungsten materials through which should diffusion the fused lithium. At Bakul institute for superhard materials scientific bases and technological aspects of receptions of powders of W up to 1000 microns which can be used as initial components for reception with the set porosity are developed. Revealing of influence of the sizes of particles of tungsten on their caking at use as the activator hydrogen-water steam the gas environment was the purpose of the present work. Sintering spent in the environment of hydrogen at temperature 1200 °С in classical flowing system and in the closed reactor. At sintering in the closed reactor after removal from samples of softener water for creation hydrogen-water steam the gas environment has been entered. Application hydrogen-water steam the gas environment has allowed sintered samples even from particles of tungsten more than 1000 microns. Such effect is caused by formation in the course of sintering gaseous tungsten based substance of type WO2(OH)2 which, reduction to tungsten in places of contact of particles, has allowed to provide between them physical contact. Thus, application of steams of water allows activating process of sintering of powders of tungsten, providing the size of a time of a material over a wide range.

Resume : In the structure of cemented carbides are different types of boundaries WC-WC (in intensity to their leaching of Murakami's reagent). The number of boundaries WC-WC and WC-Co changes depending on different technological factors. Depending on the volume content of binder phase in cemented carbides changes number of boundaries are good leached. Numbers of boundaries WC-WC are not leached and intermediate type is not dependent of volume Co content. The contiguity depends of total number of boundaries WC-WC in the structure of cemented carbides. The amount of these boundaries increases with the cobalt content decreases and the contiguity decreases. In this paper was found of dependence the contiguity of cemented carbides on the number of different types of boundaries (in intensity to their leaching of Murakami's reagent). In this regard, the physical and mechanical properties of cemented carbides are determined by the content of number of boundaries are good leached. By controlling the number of such boundaries in the structure of cemented carbides may be will affect their properties.

Resume : In this work technological properties of ceramic slurries based on Yttria for fabrication “prime coat” in ceramic shell moulds were characterized. Yttria with two different granulation (200# and 325#) in ratio (50%-50%, 35%-65% and 65%-35% by weight) was used for preparation ceramic slurries. Solid phase was 77% by weight. Technological properties like viscosity, dynamic viscosity, pH, plate weight test and density were done. For characterization yttrium III oxide SEM images, chemical composition and Zeta potential were investigated. Yttria based ceramic slurries had very promising properties and there are very perspective for future fabrication. Financial support of Structural Funds in the Operational Programme - Innovative Economy (IE OP) financed from the European Regional Development Fund - Project "Modern material technologies in aerospace industry", No. POIG.01.01.02-00-015/08-00 is gratefully acknowledged.

Resume : Hybrid structures of different types are very promising for various applicsation. One os them is photovoltaics. A heterostructure of a conducting polymer blend, poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS), and low-resistance CdS single crystal with dark resistivity of 100 Ohmcm was formed and studied by ultraviolet photoelectron spectroscopy (UPS) with photon energies of 7.7 and 10.2 eV upon a subsequent Ar+-etching of the polymer film. PEDOTT:PSS film can be deposited only by “wet” techniques such as spin-coating, its subsequent growth in vacuum is impossible. For this reason we apply the inverse method of a subsequent reduction of the film thickness by Ar+-etching. Our study concerns the polymer film deposited on the CdS surface from solution.. In the case of a spin-coated film, there can be some complicated problems that affect fundamental studies due to possible influence of solvents and atmosphere gases on the interface processes. However, the information obtained from these studies is directly related to application of the really made heterostructure. In the hybrid structure the barrier height was found to be formed due to the concomitant contributions of the interfacial dipole and the Fermi level alignment of the adjacent material in the range of 0.58-0.95 eV. The charge flow mechanisms have been discussed. Financial support of STCU project #3746 is gratefully acknowledged.

Resume : We obtained composite material based on AlN-SiC using pressureless sintering. Investigation of the structure of the material showed that yttrium oxide during sintering is converted to Al3Y5O12 and placed on the grain boundaries SiC and AlN. Thus Al3Y5O12 prevents mutual solubility of AlN-SiC. It was established that at the formation of the structure of AlN (2H)-SiC (6H)-Al3Y5O12 option slightly increases monotonically parameter с the hexagonal of lattice of AlN and parameter a decreases if in the composite material the content additives SiC increases from 20 wt.% to 50 wt.%. The parameter c increases from 0.49821 to 0.49837 nm (at 0.00016 nm), and the parameter a decreases from 0.31110 to 0.31070 nm (at 0.00040 nm). It is characterized by the formation of continuous solid solutions of AlN (2H)-SiC (2H), but the formation of solid solutions based on polytypes 2H without adding Y2O3 crystallographic parameters change more intense - almost order.

Resume : Initial samples of Ti3AlC2 MAX-phase were synthesized from mixtures of TiС/TiН2/Al in vacuum and then densified by hot pressing under 30 MPa. Ti3AlC2 –based material prepared in vacuum contained 95 wt. % Ti3AlC2. The material exhibited 22% porosity. After hot pressing, the porosity decreased became less than 1%, but the amount of Ti3AlC2 was somewhat reduced. The fracture toughness of the hot-pressed densified material estimated at 600 N load by three-point bending was K1C = 10.2 MPam0.5. Bending strength for this material reached Rbm = 503 MPa, compressive strength Rcm = 700 MPa, and Young modulus of 149.4 ± 28.7 GPa. Vickers microhardness measured at a load of 4.9 N was 4.6 ± 0.8 GPa. The study of Rockwell hardness at loads of 600 N and 1500 N showed that HRA hardness of this material was 70. The results of the heat resistance study at 600 oC in air shown that the porous Ti3AlC2 was oxidized very quickly, while the intensity of oxidation of highly dense Ti3AlC2 was lower and after 200 h of holding at 600 oC started to decrease and finished after 600 h due to the formation of dense surface oxide layer. The stability in hydrogen was studied using Ti3AlC2 samples. After exposition in hydrogen at 600 °C for 3h the porous material bending strength was reduced by 5 % only. Besides, the density of Ti3AlC2 is approximately two times lower than that of the steel. It’s make this constructive material very promising for application in hydrogen energetics, for example, in fuel cell

Resume : In the last years, vanadium rich films have been introduced as possible candidates for self-lubrication at high temperatures, based on the formation of lubricious V-O oxides. The aim of this investigation was to study the effect of V additions on the structure, oxidation resistance and tribologicalbehaviorof Ti-Si-V-N coatings deposited by DC reactive magnetron sputtering. The results achieved for TiSiVN films were compared and discussed in relation to TiN and TiSiN films prepared as a reference.The structure, mechanical properties, oxidation resistance and tribologicalbehavior of films were characterized by nanoidentation, X-ray diffraction, scanning electron microscopy, thermo gravimetric analysis (TGA) and pin-on-disc tests.All the coatings presented an fccNaCl-type structure characteristic of TiN phase. Improvement of the mechanical and tribological properties was achieved with V incorporations; however, it had a detrimental effect on their oxidation resistance due to the outwards V ions diffusion to the surface impeding the formation of a continuous Si-O protective layer. The improvement of the tribological properties with V incorporations was related to V2O5 formation on the sliding contact that acted as a lubricious tribo-film, decreasing the friction and protecting the coating from wear.TiSiN film displayed the best oxidation resistance among all the coatings, but the worst tribologicalbehavior.

Resume : Initial stages of crystal nucleation by the electrochemical methods used in the study of phase formation with simultaneous investigation of the microstructure of the substrate surface and electrolysis products were studied. It is characteristic that the height of the overvoltage maximum for the above metals is proportional to the reciprocal time of their formation (due to the penetration of the part of the deposited components into the substrate bulk). Crystallization overvoltage on the Ni substrate is observed only at certain current-density values. On a Pt substrate, we observed noticeable depolarization with two pronounced waves that seem to correspond to the formation of alloys. Experimental study of the initial stages of Mo2C electrocrystallization with the electrodes prepared from various materials over a wide temperature range allows us to put forward the following concepts of nucleation. Using the inert substrates at T < 1073–1173 K, we observed considerable crystallization hindrances associated with the formation of three-dimensional nuclei. An increase in the electrolysis temperature facilitates diffusion of atoms of the components into the substrate. Simultaneously, a transition from the three- to two-dimensional nucleation is observed and, in some instances, to depolarization phenomena due to solid-phase saturation of the boundary layers of the electrode with the components (molybdenum and carbon) and the formation of an alloy with the material of the electrode.

Resume : The main classes of composite materials as a part of National Technology platform "Advanced Materials" cluster are presented. The main results of researches which are ready for implementation in correspondance with demands of industrial end users are described. Possibilities of international cooperation with profile European Technology platform and new calls of "Horizon 2020" programme are analyzed