Materials and devices for energy and environment applicationsF
Materials and coatings for extreme environments
Intensive development of the most engineering branches from micro- and nanoelectronic and nanobiomedicine till aeronautics, automobile industry, shipping building and space devices is accompanied by formulating of new demands to the wide class of materials and coatings including composite materials and complex structures based on the metals and alloys, oxide and nonoxide ceramics, polymers and various kinds of materials reinforced by micro and nanoparticles and fibers and necessity of their exploitation in severe operation conditions. Severe operating conditions (high and cryogenic temperatures, aggressive environments, complex and alternating-sign loads, thermal cycling, enhanced pressure, microgravitation, vacuum etc,) are determined for every class of materials in separate way (for example, extreme conditions for space materials, materials for nontraditional energy and biomaterials are characterized by various parameters). The aim of symposium is the discussion of main challenges of all kinds of materials , coatings and complex structures for extreme performances with special emphasis on the novel areas of their practical using.
The need to develop materials which can perform well in severe operating environments is increasing with advances in technology and modern requirements for higher efficiency in all areas such as manufacturing, energy, transport, space, automobile industry and communications, deep-sea technologies etc. Another important driver for advanced functionalities, e.g. self-diagnosis and self-healing, comes from the incorporation of nanoscale and molecular materials components. This poses a major challenge for materials science, and requires a fundamental understanding of how the processing, microstructure, nanostructure and properties of such material interact in order to enhance their response under more severe conditions. The development of new products or components with a step change in efficiency or performance compared to existing ones, for operation in e.g. high radiation environments, highly corrosive environments, under high friction conditions, low temperature environments, deep sea or space environments, or other extreme climate conditions became more actual from year to year.
Last scientific results about investigations of bulk materials, coatings and complex structures that can function within an aggressive environment without property degradation, synthesis of new structures with useful properties will be the key topics of symposium presentations and discussions Special attention will be paid to appropriate numerical tools (e.g. density functional theory, molecular dynamics) to capture the multi-scale evolution of damage (e.g. friction/corrosion or corrosion/irradiation synergies should be considered); and predictive modeling tools for materials operating in extreme environments.
Special time of symposia activity will be devoted to innovative researches, to the questions of technology transfer and international cooperation in the field of advanced materials for extreme environments. One of the main aim of symposium is the organization of open dialog between academicians and researches from one side and representatives of industrial sector from another side to find new possibilities of creation of materials with given complex of performance properties and to determine the new areas of application of such kind of materials.
Hot topics to be covered by the symposium:
- Principles of designing of materials and coatings, including various kinds of composite materials for operation in extreme/special conditions.
- Scientific fundamentals and computer models for the processes of manufacturing materials and coating, including various kinds of composite materials for operation in extreme/special conditions.
- Advanced technologies for production and joining materials and products for exploitation in extreme conditions.
- Structure and properties of materials and coatings, including various kinds of composite materials for operation in extreme/special conditions.
- Thermal barrier coatings for details and devices for the aerospace industry.
- Advanced technologies for recycling of industrial wastes aimed for production of structural, thermal insulating, decorating and other materials.
- Technology transfer as a catalyst of innovation development of society.
Tentative list of invited speakers:
- Shemet V (Jülich, Germany)
- Tedenac Jean-Claude (Montpelier, France)
- Dorofeef Vladimir (Novocherkassk, Russian Federation)
- Brziak Peter (Bratislava, Slovakia)
- Mileiko Sergey (Moscow, Russian Federation)
- Prikhna Tatiana (Kiev, Ukraine)
- Polezhaev Yurii (Moscow, Russian Federation)
- Savich Vadim (Minsk, Belorus)
- Gergii Tavadze (Tbilisi, Georgia)
- Konstantinova Tatiana (Donetsk, Ukraine)
- Frage Nahum (Bersheva, Israel)
- Rumyantsev Vladimir (Sankt-Peterburg,Russian Federation)
- Kervalishvili Paata (Tbilisi,Georgia)
- Berber Alik (Haifa, Izrael)
Tentative list of invited speakers:
- Uvarova Iryna (Kiev, Ukraine)
- Ragulya Andrey (Kiev, Ukraine)
- Turkevich Vladimir (Kiev, Ukraine)
- Ilyushchenko Aleksandr (Minsk, Belorus)
- Panin Victor (Tomsk, Russian Federation)
- Kulu Priit (Tallinn, Estonia)
- Zgalat-Lodzynsky Ostap (Kiev, Ukraine)
- Gogotsi Yu. (Drexel University, USA)
- Loboda Petro( Kiev, Ukraine)
- Hipke Thomas (Chemnitz, Germany)
- Vishnyakov Leon (Kiev, Ukraine)
- Pakiela Zbigniew (Warsaw, Poland)
- Iryna Bilan (Kiev, Ukraine)
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Authors : 1-Barbara Romelczyk, 2-Anatolii Laptiev, 2-Oleksandr Tolochyn, 1-Tomasz Brynk, 1-Zbigniew Pakiela
Affiliations : 1- Warsaw University of Technology, Faculty of Materials Science and Engineering, Warsaw, Poland; 2- Frantsevich Institute for Problems of Materials Science of NASU, Kyiv, Ukraine
Resume : For carrying out comparison iron powders from two producers were chosen: coarse powder with a size of particles 25-40 mm (PZh3M2, Ukraine) and fine powder - 2 - 5 mm (DIAFe5000, Germany). Impact sintering of these powders was carried out in vacuum in the range of temperatures of 600-1100 ° C. On samples density, structure and various mechanical properties depending on the impact sintering temperature are determined. As a result of comparison of properties it is established that the absolute density of samples from coarse powder is less than density of samples from fine powder (7.86 versus 7.92 g/cm^3), and specific electrical resistivity of the first samples is higher than resistivity of the second samples (11.4 versus 10.4 mOm´cm) independently of the consolidation temperature. It is connected not so much with the size of initial particles of iron powder, how many with the different content of impurity in powders. In coarse powder the raised content of oxygen, manganese, silicon is revealed. The distinctions of initial powders at a size of particles and in a chemical composition caused various behavior of the compared samples at the mechanical tests and the different mechanical properties. In particular, impact sintering of samples at 700 and 1100 °C led to the following results: tensile ultimate strength of samples from coarse powder equal to 406 and 322 MPa respectively, and the ultimate strength of samples from fine and purer powder equal to 336 and 239 MPa. Such important characteristic of plasticity as contraction was higher at samples from fine powder. Namely, for the samples obtained at 700 and 1100 °C, contraction equal to 78 and 84% for the powder DIAFe versus 26 and 61% for the powder PZh3M2. At the same time, the yield stress is higher at the samples from coarse powder: 352 and 215 MPa versus 189 and 133 MPa for the consolidation temperatures of 700 and 1100 ° C respectively.
Authors : Katarzyna Konopka
Affiliations : Warsaw University of Technology, Faculty of Materials Science and Engineering,
Resume : Ceramics with strength, high hardness, chemical inertness, high melting point are a group of materials for demanding applications as automobile industry, aeronautics, high temperature devices as well as biomaterials. However, the brittleness of ceramics limits the work under stress. The ceramic-metal composites are the solution. There are well described mechanisms of improving the fracture toughness. They depends on various microstructural factors as the combination of ceramics and metal, size and distribution of metal particles or new phases and interfaces. In some ceramic-metal system more than one mechanism of improving fracture toughening can operate. Especially, in composites from ZrO2-Ti system the synergy of toughening mechanisms are possible. Zirconia is the transformation-toughened engineering ceramics. In zirconia-titanium composites Ti might have an influence on the transformation of tetragonal ZrO2 into monoclinic. The incorporation of Ti particles can improve the fracture toughening by mechanism of crack deflection or bridging. Moreover, taking into account possible reaction between Ti and ZrO2 various compounds can be formed and also give synergetic effect into the improving the fracture toughening. In the present review paper the mechanisms of improving fracture toughness in ceramic-metal composites will be described and disused in aspect of their domination in composites. The possible synergy of toughening mechanisms will be analyzed. ACKNOWLEDGEMENTS This work was supported by The National Center of Science (NCN), project DEC-2013/11/B/ST8/00309.
Authors : B. Kalska-Szostko*, U.Wykowska*, D. Satuła#
Affiliations : * Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Białystok, Poland #Department of Physics, University of Bialystok, Ciolkowskiego 1L, 15-245 Białystok, Poland
Resume : Magnetic nanoparticles are widely investigated in many areas, where among others can be strongly emphasized medicine and environment protection . Magnetite in nano form is known as non-toxic and well biodegradable, therefore studies on its stability in nanostructures form become interesting for our team. Therefore, investigations of nanostructures resistance in destructive environments have been performed. For such instance, we have chosen few model solutions: distilled water, acetic acid, citric acid, saline, and ethanol . Magnetite nanoparticles were kept in those solutions for certain time, and then analysis of nanoparticles and the solutions were performed. Particles with modified core or surface layer were compared. Examination of nanoparticles before and after treatment in chosen solutions included TEM, IR, X-ray, and Mössbauer spectroscopy studies. The solutions content after experiment were measured by AAS. As a continuation of this studies, are planned tests of nanoparticles behavior in environmental solutions, for instance wastewater and river water.  S. Khizroev, M. Kryder, D. Litvinov, D. Thomson, Appl. Phys. Lett. 81 (2002) 2256  B. Kalska-Szostko, U. Wykowska, K. Piekut, D. Satuła, Colloids and Surfaces A: Physicochemical and Engineering Aspects 450 (2014) 15-24
Authors : Renata Porebska1 , Andrzej Rybak1, Barbara Kozub2, Robert Sekula1
Affiliations : 1-ABB Corporate Research Center, 2-Cracow University of Technology, Faculty of Mechanical Engineering
Resume : The aim of the presented work is an evaluation of wood polymer composites for application in power products. Samples based on polypropylene, polystyrene, polyoxymethylene, acrylonitrile butadiene styrene, polyester resin and polylactic acid with different contents of cellulose fibers were prepared by injection molding process. The mechanical and dielectric properties of these composites were studied in order to check whether investigated wood polymer composites fulfil requirements for their application in power products. For all tested composites a linear increase of modulus with cellulose content was observed. Addition of cellulose to the tested polymers significantly reduces strain at break. In the case of polypropylene and polyoxymethylene composites, the tensile strength increases with the content of the filler. For other materials, there is an inverse relationship, namely addition of cellulose decreases the tensile strength. The electrical strength decrease was observed with increased cellulose content for majority of investigated composites. Polar groups incorporated by cellulose fibers have led to dielectric constant increase. Furthermore, aging of composites in mineral oil and evaluation of water uptake for wood-plastic samples were performed. Wood polymer composites have changed significantly after aging. The water diffusion coefficients were determined and the significant influence of the amount of cellulose on the water absorption was shown.
Authors : Mikolaj Szafran, Pawel Falkowski, Emilia Pietrzak, Malgorzata Gluszek
Affiliations : Warsaw University of Technology, Faculty of Chemistry
Resume : Ceramic processing, including shaping of high performance materials and coatings requires new, effectively working processing agents like deflocculants, binders, organic monomers, etc. The results of studies on the application of new water-soluble dispersants and monomers which are then used in the preparation of ceramic colloidal suspensions of high stability and low viscosity. The amphiphilic macromonomers, due to the proper ratio of the hydrophilic to hydrophobic fragments, play the role of not only an internal plasticizer, but they also modify the adhesion of such binders to the ceramic powder particles and substrates. The influence of chemical structure of these copolymers on the properties of ceramics will be discussed. The authors elaborated the synthesis route of acrylic derivatives of saccharides, which have many advantages. They are non toxic, water-soluble, inexpensive and renewable materials. The research showed that the synthesized compounds could play multifunctional role in gelcasting of ceramic powders: organic monomers able to polymerize in situ, compounds forming self cross-linked polymeric network without external additives and dispersing agents for selected nanopowders. These studies were supported by the Polish National Science Centre under Grant No. 2013/11/B/ST8/0029 and Warsaw University of Technology.
Authors : Paulina Wiecinska, Anna Wieclaw, Emilia Pietrzak
Affiliations : Warsaw University of Technology, Faculty of Chemistry, Department of Chemical Technology
Resume : Preparation of advanced ceramic materials and coatings requires the use of various organic additives which facilitate shaping process of non-plastic ceramic powders. The organic substances can play the role of dispersing agents which stabilize suspensions, binders which hold particles together, plasticizers which give elasticity, monomers together which activators and initiators of polymerization which allow to create polymeric network around powder particles. These additives are subsequently burned-out during sintering process. They are indispensible in shaping step but must be then eliminated in order to obtain pure ceramic phase. For this reason the knowledge about thermal degradation of organics used, as well as decomposition products, seems to be very important from the application point of view. The thermal analysis has been done on the apparatus coupled with mass spectrometer what allowed to observe what types of gasses are released to the atmosphere during heating. It was possible to determine at what temperature regions harmful gases like N2O, NO2 or SO2 are released from the organics and which additives can be treated as environmentally friendly. Thermal analysis allowed to determine the stability regions of prepared ceramic samples. The project has been financially supported by the Warsaw University of Technology, Faculty of Chemistry.
Authors : P.Falkowski
Affiliations : Warsaw University of Technology
Resume : In recent years there has been growing demand for microfluidic devices such as ceramic microreactors. The application of ceramic microreactors is expected to have a number of advantages like high heat and mass transfer rate reactions as well as excellent thermal and chemical resistance. Thus, the reaction can be performed under more aggressive conditions with higher yields than it can be achieved with conventional reactors. The ceramic microfluidic devices can be manufactured by combination of tape casting and soft lithography method. In soft lithography and tape casting it is possible to apply the UV curable ceramic dispersion. Such combination allows manufacturing instantly the ceramic material with internal structures such as channels, layer-by-layer without stacking of ceramic tapes and lamination process. In this work a photopolymerization of ceramic dispersions in UV curable monomer was used to manufacture the ceramic microreactor by combination of tape casting and soft lithography technique. The effect of particle size and powder concentration on viscosity, cure depth and relative density were investigated. This work was financially supported by Faculty of Chemistry, Warsaw University of Technology The authors would like to thank BTC Europe GmbH for free samples of Irgacure photoinitiators.
Authors : L. Vyshniakov (1), L. Pereselentseva (1), K. Vyshniakova (1), A. Tagliaferro(2), P. Jagdale (2), I. Cannavaro(2)
Affiliations : 1- Frantsevich Institute for Problems of Material Sciences of NAS of Ukraine; 2- Politecnico di Torino, Torino, Italy-10129
Resume : Bio char based carbon and graphene nano structures are very perspective materials for nanoprofiling and modification of polymer composites reinforced by carbon fibers to be used in space, aviation and automotive applications. In this work the materials obtained from pyrolysis and carbonization of pine chips were studied. Techniques such as X-ray diffraction analysis, Raman spectroscopy and transmission electron microscopy were used for structural and morphological characterization of graphite and multilayer graphene nanoparticles that are formed in the 400 to 600° C temperature range On the base of experiment and data analysis, we concluded that the carbonized product of pine chips by pyrolysis consist of two phases, crystalline and amorphous which is confirmed by Raman. Hence this process can be an effective and cheap way to produce graphite and/or graphene nanosheets. The investigations had been supported by FP7 project FIBRALSPEC.
Poster session : Prof. Valerii Skorokhod, Prof. Iryna Uvarova
Authors : Iu. Nasieka, V. Strelchuk, Yu. Stubrov, M. Boyko, S. Dudnik, K. Koshevoy, V. Strel?nitskij
Affiliations : Iu. Nasieka, V. Strelchuk, Yu. Stubrov, M. Boyko - V.Ye. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 45 Pr. Nauky, Kyiv, 03028, Ukraine S. Dudnik, K. Koshevoy,V. Strel?nitskij - National Science Center ?Kharkov Institute of Physics and Technology?, 1, Akademicheskaya St., Kharkov, 61108, Ukraine
Resume : Up to date, nanocrystalline diamond (NCD) films are regarded as a new material with a high application potential in electronic devices operating in extreme environments. In Ukraine, the works for the synthesis of NCD films are carried out in National Science Center ?Kharkov Institute of Physics and Technology?; here, the deposition method and corresponding setup for diamond films deposition based on the D-C glow discharge in the crossed E/H fields (chemical vapor deposition) were developed. Optical investigation of these diamond materials are performed in V.Ye. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine. The diamond coatings were deposited from the operation mixture CH4/H2 with addition of N2 in various concentrations. It was ascertained that addition of N2 to the operation gas mixture leads to reduction in the sizes of diamond grains as well as to the substantial decrease in the resistivity of the studied films. The electro-physical data are in good agreement with the changes induced by varying the N2 content in the Raman scattering spectra. The increase in the N2 concentration causes significant lowering the crystalline diamond related peak and increase in the intensity of the peaks related to the sp2-bonded carbon. These changes in the spectra indicate significant disordering the structure of the films and can be associated with a decrease in the sizes of diamond crystalline grains and tendency of NCD film to amorphization.
Authors : Yegor Brodnikovskyi, Dmytro Brodnikovskyi, Iryna Brodnikovska, Mykola Brychevskyi, Igor Polishko, Oleksandr Vasylyev
Affiliations : Frantsevich Institute for Problems of Materials Science of NASU, Krzhizhanivsky str. 3, 03680, Kyiv, Ukraine
Resume : Zirconia (zirconium dioxide) is a very perspective material for SOFC anode making due to its good combination of mechanical and electric properties. Despite the widespread use of 8YSZ (8-mol. % Y2O3 – ZrO2) for making of SOFC during a past decade, for today most perspective for low temperature (600-800 °C) composition is considered 10Sc1CeSZ (10 mol.% Sc2O3 - 1 mol.% CeO2 – 89 mol.% ZrO2), as it has higher ionic conductivity. Using ceramic component of increased strength while keeping sufficient ionic conductivity results in enhanced SOFC’s anode efficiency at operating temperatures. The aim of this work was to study the creation patterns of 10Sc1CeSZ – 3.5YSZ (3.5-mol. % Y2O3 – 76.5- mol.% ZrO2) system for application as a ceramic component of the SOFC. For this purpose, the influence of 3.5YSZ content on strength and electrical conductivity of 10Sc1CeSZ –3.5YSZ composite were studied. Methods: SEM, XRD, biaxial bend test, impedance spectroscopy.
Authors : Olena Sych1, Artem Iatsenko2, Lesya Panchenko3, Tamara Tomila1, Yan Evych1
Affiliations : 1Frantsevich Institute for Problems of Materials Science of NAS of Ukraine, Department of Physical-Chemical Foundations of Powder Materials Technology, 3, Krzhyzhanovsky Str., Kyiv 03680, Ukraine 2National Technical University of Ukraine Kyiv Politechnical Institute, Department of Ceramics and Glass Chemical Technology, 37 Peremogy Ave., Kyiv 03056, Ukraine 3Institute of Traumatology and Orthopedics of NAS of Ukraine, Laboratory of Immunology, 27, Boulevard-Kudryavskaya Str., Kyiv 01601, Ukraine
Resume : Highly porous ceramics on the basis of biogenic hydroxyapatite (BHA) and glass of the SiO2-CaO-Na2O system have been prepared using a replication techniques for the structure of a polymer template in the temperature range 8001100 °Ñ. It has been established that decreasing of BHA content from 70 to 50 wt. % leads to the decomposition of BHA and interaction with glass mass, which results in forming such phases as renanit NaCaPO4, calcium silicate phosphate Ca5(PO4)2SiO4, calcium pyrophosphate Ñà2Ð2Î7 and hydroxyapatite Ca5(PO4)3(OH), which was confirmed by IR spectroscopy results. An increase in sintering temperature over 1000 °Ñ causes marked volume shrinkage to 76 % and pore structure transformation from an open into closed type. Samples prepared at 900 °Ñ exhibit optimal structural-mechanical properties. They are characterized by a permeatable structure with a predominant pore size of ~ 125 µm and small volume shrinkage of 9-12 %, which makes it possible to fabricate samples with required shape, size as well as total and open porosity of 78-82 and 76-63 %, respectively, and a compressive strength of 0.9-1.0 ÌPà. Moreover, it was found the significant increase in performance osteogenic activity of stem stromal marrow cells of ilium outside the local foci of inflammation and degenerative lesions of human bone tissue in the presence of glassceramics. The materials obtained are promising for replacement of defective bone tissue in orthopedy and traumatology.
Authors : Marcin Malek1*, Pawel Wisniewski1, Jaroslaw Mizera1, Krzysztof Jan Kurzydlowski1
Affiliations : 1Faculty of Materials Science and Engineering, Warsaw University of Technology, * Corresponding author: firstname.lastname@example.org
Resume : This work present results of the technological properties of ceramic slurries based on silicon carbide powder. For ceramic slurries preparation SiC F400 powder and binder with nanoparticles of Al2O3 were used. To modification technological parameters two polyacrylic binder were added. Solid content was 62,5 wt.%. Standard industrial parameters like: viscosity, density, temperature and pH were measured every day. For better characterization rheological properties of investigated ceramic slurries dynamic viscosity was done. Tests were taken 96h in laboratory condition. Silicon carbide properties: SEM images, grain size and chemical composition were studied. Obtained results shown that ceramic slurries based on SiC and new polyacrylic binder were stable vs. time and meet the standard industrial requirements. Properties of tested ceramic slurries are promising in further fabrication of ceramic shell moulds. 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.
Authors : J. Szymanska, P. Wisniewski,M. Malek, J. Mizera
Affiliations : Warsaw University of Technology; Faculty of Materials Science and Engineering; Woloska 141 Street; 02-507 Warsaw;
Resume : This work concerns characterization of ceramic proppants applied in hydraulic fracturing during extraction of shale gas. Propping agents pumped with liquid into the deposit cause cracking of the rock. The role of these materials is to avoid closing of formed pores and to enable facilitated gas migration from deposit. Due to processing requirements and conditions in formations (high pressure and temperature), proppants should be characterized by proper physico- mechanical properties. The investigation relates to properties of five kinds of proppants obtained by the mechanical granulation method. Bulk density, roundness coefficient, porosity, pores size distribution, moisture content, turbidity and solubility in acid were examined. Mechanical strength of proppants was established during subjection to the crush test at increasing stress. Structure and morphology of ceramic pellets were determined by the Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS) and X-Ray Tomography. The results indicate that composition, grain size distribution and morphology as well have an important influence on their fundamental properties during shale gas permeability through the fracture. Keywords: ceramic proppants, granulation, raw materials, shale gas, hydraulic fracturing Financial support of BLUE GAS Programme financed from The National Centre for Research and Development Project: Optimizing the lightweight high strength and low specific gravity ceramic proppants production technology maximally using naturally occurring Polish raw materials and fly ash , No. BG1/BALTICPROPP/13 is gratefully acknowledged.
Authors : Adamovskyi A.A., Kostenko A.D., Varchenko V.T.
Affiliations : I.Frantsevich Institute for Problems of Materials Science, NAS of Ukraine
Resume : To examine the tribological characteristics of the friction pairs SHM-SHM under dry friction by butt-to-butt scheme. The test objects were production pieces of SHM, i.e. the composites based on the dense modifications of BNsphalerite: composite 01, composite 10, composite 05-IT. The friction pairs were tested by the following regimes: sliding velocity, m/s: 0.1; 0.2; 0.3; load, N: 350; 450; 650; 850; 2100; 3600; dry friction in air. When testing we determined the friction coefficient. The surface roughness of the SHM before the test was Ra = 0.30-0.50 µm. The tribological characteristics of friction pairs of the same superhard materials have been examined. The SHMs exhibited extreme wear resistance in the friction pairs of the same material. The maximum wear resistance under dry sliding showed friction pair composite 10-to- composite 10. In the friction pair composite 05-IT-to- composite 05-IT under sliding speed of 0.1 m/s the decrease in coefficient of friction from 0.40 to 0.06 was observed with increasing load from 350 N to 3600 N. So, an increase in the load by 10.2 times reduced the coefficient of friction by 6.6 times. SHM surface roughness after testing was Ra = 0.15-0.18 µm. The study of friction surfaces showed that the samples were working in the area of elastic deformation. The tested SHMs in friction pairs under dry friction conditions can be ranked as follows with respect to decrease in friction coefficient: composite 01- composite 05-IT - composite 10.
Authors : Naidich Yu.V., Durov O.V., Sydorenko T.V., Karpets M.V., Koval O.Yu.
Affiliations : I.Frantsevich Institute for Problems of Materials Science, NAS of Ukraine
Resume : Wetting of titanium dioxide with iron triad metals was considered in the present work. At interaction of iron and cobalt containing melts to rutile additional liquid phases forms. Temperatures if its appearance (1650 K for iron and 2100 K for cobalt) are in good correlation to temperatures of FeO and CoO melting. From the X-ray diffraction and SEM investigation for iron case second liquid is eutectic between titanium dioxide and pseudobrookite (Fe3Ti3O10), for cobalt case second liquid is eutectic between titanium dioxide and some of ternary Ti-Co-O compound. In nickel case second liquid phase is not observed because NiO in vacuum decomposes before melting.
Authors : Naidich Yu.V., Stetsyuk T.V., Sydorenko T.V., Durov O.V., Kostyuk B.D.
Affiliations : I.Frantsevich Institute for Problems of Materials Science, NAS of Ukraine
Resume : In space conditions the electron-beam welding is perspective method to obtain of seams which have good physical and mechanical properties (in weightlessness the molten metal is held in container by surface tension, which generally decreases when the temperature of experiment is increased). For development of new generation of electron-beam emitter the technology of producing of brazed ceramic-metallic joints with complicated design (form) of the ceramic parts was optimized. The samples of high-voltage insulator for electron-beam emitter were produced for work in microgravity. It was proposed a 3th-layers form of the filler (like a "sandwich"): base (Ag, Cu) / titanium / base (Ag, Cu). Work properties of the brazed joints were studied: the tightness (up to 5 atm), the thermal-cycling stability (40 cycles, Т = 770K - 290K - 770K), the cold endurance (up to 198K).
Authors : Olena Poliarus, Oleksandr Umanskyi
Affiliations : Frantsevich Institute for Problems of Materials Science NASU
Resume : Today the problem of protection of various parts for shipbuilding engineering, hydropower equipment, floating oil and gas platforms from the action of aggressive media, including seawater, is very urgent. Therefore the development of composite coatings of the NiTi MeB2 systems is promising. The intermetallic NiTi is known to preserve high strength, hardness and wear resistance up to 400°C under the conditions of combined cavitation and erosion wear. Additionally, it exhibits high resistance to oxidation and corrosion in alkalis, acids, water and neutral media. The present work is devoted to study of wettability and peculiarities of contact interaction in the NiTi-CrB2 system. The intermetallic NiTi has been shown to wet chromium diboride with formation of wetting angle 10°. The phase and chemical compositions of the products in the interaction zone were analyzed. It was established that the chemical interaction between the initial components results in forming a new phase, namely TiB2. Based on the investigation findings for the contact interaction, chromium diboride was selected as an additive to create a new corrosion resistant composite material on the basis of intermetallic NiTi. The microstructure of the developed composite material of the NiTi-CrB2 system and its behavior in aggressive corrosive media, in particular in seawater, were thoroughly studied.
Authors : Grigorenko M., Chernigovtsev E.
Affiliations : I.Frantsevich Institute for Problems of Materials Science, NAS of Ukraine
Resume : At first stage for a number of contacting model pairs: olive, castor oil - glass, paraffined glass; water glass; paraffined glass; water/ethanol glass, paraffined glass wetting studies in the air atmosphere were performed by a sessile drop method. Taking into account wetting data obtained for particular contacting pairs at the second stage wetting and spreading peculiarities were studied in dynamics by video filming for liquid (oil) contacting with solid surface (glass, paraffined glass) immersed in another liquid (water, water-ethanol solution) immiscible with the first one and having density equal to that of said solution (thus imitating microgravity/zero-gravity state) - at liquid1-solid-liquid2 interface. The results obtained - in particular different and rather strongly distinguished degrees of wetting and liquid-solid interface movement velocities for some contacting pairs can have practical application e.g. for modeling and studying the processes of purposeful liquid capillary transportation, liquids separation and purification at microgravity conditions and development of appropriate space technologies.
Authors : S.I. Sidorenko, S.M. Voloshko, A.P. Burmak
Affiliations : National Technical University of Ukraine «Kiev Polytechnic Institute», Peremogy av.37, Kyiv, 03056, Ukraine
Resume : Regularities in the formation of phase and chemical composition, fine microstructure and mechanical properties of surface layers in D16 aluminum alloy under the UIT in the conditions of quasi-hydrostatic compression of samples in rare gases and liquid nitrogen ambient were studied in this paper. A cyclic character of microhardness change in surface layers of D16 alloy depending on oscillation amplitude of tensions concentrator and time of UIT in an inert environment was revealed, which consists in alternation of work-hardening stages, conditioned by structure and phase transformations, as well as plastification stages due to the development of dissipative processes of dynamic recovering and dynamic recrystallization. Work-hardening (in 2,5 time) of D16 alloy surface by means of UIT in an inert environment is conditioned by modification of dislocation structure, deformation forming of nanocrystal structure, and precipitation of nanosize strengthening S' phases. It is shown the unique possibility of work-hardening of D16 alloy surface (in 5 times) by UIT treatment in the liquid nitrogen ambient, conditioned by synergetic influence of nanostructuring and micro chemical impact processes on aluminum in the process of criodeformation. Cyclic character of changes of micro hardness it is not discovered in this case. The development of dynamic recover processes and the evidences of the dislocation annihilation effect are prevented by deep cooling up to the criotemperatures.
Authors : Naidich Yu.V., Sydorenko T.V., Poluyanskaya V.V.
Affiliations : I.Frantsevich Institute for Problems of Materials Science, NAS of Ukraine
Resume : The tin oxide ceramics have specific optical and electrical properties and a good chemical stability. Such ceramics can used in electronics, electrical engineering, electrochemistry, catalysis, biotechnology, metallurgy, atomic and chemical industries, etc. SnO2 belongs to the important class of transparent conductor oxide materials that combine low electrical resistance with high optical transparency in the visible range of the electromagnetic spectrum. These properties are required for optoelectronic applications, light emitting diodes, electrode materials in solar cells flat panel displays, transparent field effect transistors. The reliable electrical contact can be obtained by brazing technology. The wetting joined materials are important for the development of fillers. In this work the wetting of tin oxide ceramic substrate by liquid metals was investigated at high temperatures both in air and in vacuum. The contact angle of pure Ag on surface of tin oxide was 100 degrees in air and 110 degrees in vacuum. Addition of Cu to Ag-melt in air leads to fall in the wetting angle (up to 14 degrees for alloy with 40 at.% Cu) and to raise of the contact angle (up to 120 degrees for same alloy) in vacuum. The microstructure of the transition zone of metal/ceramic interface was studied. The comparison of the wetting in air of tin oxide and other classic oxides was carried out.
Authors : P. Łada, A. Miazga, J. Woźniak, K. Konopka, A. Olszyna
Affiliations : Warsaw University of Technology, Faculty of Materials Science and Engineering
Resume : Zirconium oxide stabilized by 3 mol.% yttrium oxide is one of the ceramics materials which is using to dental applications, thermal barrier coatings or as a cutting tool material. The properties of this ceramics include high flexural strength, high fracture toughness, high hardness, wear resistance, low thermal conductivity and corrosion resistance in acid and alkalis. One of the method to change the proprieties of zirconium oxide is incorporating a second-phase reinforcement into ceramics matrix. Titanium is a metal which have a wide application including aerospace, automotive, biomedical and chemical industry. The main proprieties of titanium are high strength-to-weight ratio, excellent corrosion resistance, biocompatibility and low mass-to-volume ratio. The combination of these two materials should create a composite which exhibits enhanced mechanical and thermal properties than the two participating components. This work shows the preliminary analysis of composite from the ZrO2 ? Ti system. The samples were prepared from the nano-size ZrO2 powder stabilized by 3%mol Y2O3 and 10% by volume Ti powder with particle size about 15?m. The samples were formed by spark plasma sintering (SPS). The parameters of SPS process was: in temperature 1350?C, with pressure 20MPa and time 10min, with a heating rate of 100?C/min. All process was lead in an inert atmosphere, in argon. The densities of the green body and sintered ZrO2-Ti composites were determined by Archimedes method. The microstructural characterization was carried out using an x-ray diffraction and a scanning electron microscope (SEM) with EDS analysis. Additionally, the Vickers hardness and fracture toughness were measured. Obtained composite samples have a density about 98-99% of theoretical value. During the process was used a graphite die which can react with mixing powder and in effect, on the surface of samples can appear new compounds like TiC. The SEM observation and EDS analysis confirmed that the Zr and Ti are distributed homogenously in analyzed areas. Moreover, the x-ray diffraction reveal the existence of a new phase Ti2ZrO. Keywords Zirconium oxide, titanium, spark plasma sintering (SPS), composite, cermets Acklowledgements The work was done in frame of the project financed by National Center of Science (NCN), project DEC-2013/11/B/ST8/00309.
Authors : Svetlana Chernega, Igor Poliakov, Mihael Krasovskiy
Affiliations : National Technical University of Ukraine "Kiev Polytechnic Institute", Kiev Institute for Problems in Materials Science (IPMS) NAS of Ukraine
Resume : In this paper investigated the structure and phase composition of boron coatings obtained after complex saturation with boron and copper low-carbon steels at applying an external magnetic field (EMF). This method obtaining boron coating allows in 1.5 2 times to reduce the period saturation detail and get coatings with high hardness, wear resistance, corrosion resistance. At applying the EMF changing morphology boron layers, needles grains decreases sharply, disappear individually disappear sprouted grain borides in the matrix. Needles boron phases closely adjoin to each other and formed a continuous, homogeneous boron layer thickness is in 2 times higher than the boriding without EMF. Established that the diffusion saturation in boriding mixture during 4 hours without EMF obtain coating thickness is 150 microns, then, as at overlay EMF during 2 hours formed coating thickness is 200 microns; complex saturation with boron and copper during 4 hours without EMF formed coating 175 microns, then, as at overlay EMF after complex saturation with boron and copper during 2 hours formed boron diffusion phase thickness is 230 microns. At applying EMF in boron layers observed decrease of volume phase FeB and on diffraction patterns taken from the surface of boron coatings recorded the presence of phases FeB and Fe2B, and after complex saturation with boron and copper formed phases FeB, Fe2B and Cu.
Authors : S. Kochetova, D. Shakhnin, A. Gab*, T.Stetsyuk**, N. Kushchevskaya***, V. Malyshev
Affiliations : V.I. Vernadsky Institute of General and Inorganic Chemistry, NAS of Ukraine, Kiev, Ukraine *National Technical University of Ukraine, Kyiv Polytechnical Instritute, Kyiv, Ukraine ** Frantsevich Institute for Materials Science Problems of NAS of Ukraine, Kyiv, Ukraine ***University "Ukraine", Kiev, Ukraine
Resume : Urea and acetamide based ion-organic melts are environmentally safe, stable, and technologically convenient solvents for refractory and noble metals salts, having low melting point and sufficiently broad "electrochemical window". Au wire electrochemical behavior was studied in eutectics urea-NH4Cl (16.8 mol. %) and acetamide-NH4Cl (11,3 mol. %) melts at 393 and 373 K, respectively. During Au anodic dissolution in urea melt, Au (III) planar complexes are formed, and in acetamide one - presumably Au (III) octahedral ammonia complexes. In both of studied melts, Au (III) complexes irreversible cathodic reduction to metal takes place in diffusion regime in two stages: Au (III) Au (I) Au (0). Potentiostatic electrolysis of urea-chloride melt with Au anode resulted in 5 microns thick metal deposit with particle size 50-100 nm. Potentiostatic electrolysis of acetamide-NH4Cl melt with Au anode resulted in gold coating deposition onto substrate with individual particles size 200-300 nm.
Authors : A. Podyman, N. Sushynskiy, D. Shakhnin, A. Gab*, I. Gab**, V. Malyshev, J. Shuster***
Affiliations : Institute of General and Inorganic Chemistry, NAS of Ukraine, Kyiv, Ukraine *National Technical University of Ukraine Kyiv Polytechnical Instritute, Kyiv, Ukraine **Frantsevich Institute for Materials Science Problems of NAS of Ukraine, Kyiv, Ukraine ***University of Vienna, Vienna, Austria
Resume : Tungsten silicides have wide variety of industrial applications from protective coatings for constructional materials to alternative semiconductors films for solar panels. Particularly, refractory metals silicides coatings deposited by currentless method from molten salts can help to improve some mechanical and physico-chemical properties of construction materials, namely refractoriness, oxidation resistance, and corrosion resistance. Strongly adherent, continuous, and poreless tungsten disilicide coatings were obtained at the tungsten sample surface from the molten NaCl-KCl (eut.) NaF (20 mol. %) mixture containing 5 mol. % of Na2SiF6 and 20 mol. % of elementary Si at the 1123 K on air during 16 hours. The SEM of the cross-section slice has shown the obtained WSi2 coating at the tungsten surface. Strong adhesion between the coating and the substrate was shown together with the absence of Kirkendall voids and any intermediate layers usually consisting of low silicides.
Authors : N. Uskova, D. Shakhnin, A. Gab*, I. Gab**, N. Kushchevskaya***, V. Malyshev V.I. Vernadsky Institute of General and Inorganic Chemistry, NAS of Ukraine, Kiev, Ukraine
Affiliations : *National Technical University of Ukraine Kyiv Polytechnical Instritute, Kyiv, Ukraine **Frantsevich Institute for Material Science Problems of NAS of Ukraine, Kyiv, Ukraine *** University "Ukraine", Kiev, Ukraine
Resume : To isolate the tungsten compounds from ores and concentrates, method is commonly used of dissolution in various acids which poor performance and environmental hazards are doubtless. As an alternative method, high-temperature selective extraction (HTSE) can be proposed using non-corrosive chloride-silicate melts NaCl-Na2SiO3.During these melts interaction with tungsten concentrates (wolframite or scheelite), tungsten compounds are transferred into the chloride phase, and iron, manganese, and calcium oxides - into the silicate one.Then, phases are separated by selective decantation. The extraction process is carried out in a silicon carbide crucibles. Charge for HTSE contained in weight %: NaCl - 45,0; Na2SiO3 - 20.0; wolframite - 35.0.Process temperature was 1273-1373 K, duration - 2 h.The liquid halide-tungstate phase was decanted to a separate crucible for further electrolytical isolation of tungsten in the form of nanodispersed powders.
Authors : Yu.Naidich, I.Gab, T.Stetsyuk, S.Martynyuk
Affiliations : Frantsevich Institute for Materials Science Problems of NASU
Resume : The film continuity is determined by the ratio of the metal film adhesion and cohesion to the oxide surface. Accordingly, systems with high adhesion and wettability oxides by metals the have been selected. In this work the kinetics of dispersion-coagulation during annealing in vacuum of niobium, hafnium and zirconium nanofilms deposited onto oxide (sapphire, ceramics based on ZrO2) materials was investigated. It was found that these films deposited onto oxides have almost no changes its structure during annealing up to 1400 oC, and under further rise annealing temperature films disintegration process was intensified significantly. This disintegration of films on both oxides has approximately the same character and almost finished as a result of annealing for 20 min with simultaneous coagulation of small film fragments into larger conglomerates. The intensity of niobium films dispersion onto investigated oxides is slightly higher compared to hafnium and zirconium films. This phenomenon can be explained by different affinity for oxygen of these metals. Kinetic curves decay of the investigated nanofilms on mentioned non-metallic substrates have been fitted. The resulting experimental data can be used in practice for development of new technological modes of joining by brazing or pressure welding of metallized nonmetallic materials.
Authors : G.A. Bagliuk, O.V. Tolochyna, O.I. Tolochyn, R.V. Yakovenko
Affiliations : Franctsevich Institute for Problems of Materials Science NAS Ukraine
Resume : Due to low raw-material cost, low density, high strength, good wear-resistance, excellent oxidation resistance and sulfurized corrosion resistance, Fe3Al based materials have been attracting a lot of attention for promising industrial applications. As is known, introduction of refractory particles TiC to Fe3Al intermetallic matrix promotes increase of their mechanical characteristics. The mechanical properties and microstructures of Fe?16Al based composites reinforced with 5?15 wt.% TiC ceramic particle, produced by hot forging method, were investigated. The composite was received from a mixture of powders Fe, Al and TiC. During heating of intermetallic compounds Fe3Al synthesis was used. Synthesized samples Fe3Al-TiC was forged at 1150 ?C. The relative density of all the composites was up to 99%. Using the received samples the complex physical and mechanical properties (density, electrical resistivity, bending strenght, fracture toughness, hardness) were researched. The structure of composites and uniformity distribution of TiC in a matrix phase were researched.
Authors : A.Sáez-Maderuelo, D. Gómez-Briceño, C. Maffiotte
Affiliations : Ciemat
Resume : The Generation IV (Gen IV) nuclear reactors are the future option of the nuclear industry. The aim of Gen IV nuclear power plants is enhance the efficiency and safety of the Light Water Reactors (LWR) currently in use. Among the Gen IV designs, the Supercritical Water Reactor (SCWR) is the natural evolution of the LWR. The SCWR uses water as coolant, although at higher temperature and pressure in order to get into de supercritical region (the critical point is at 374 ºC and 22.1 MPa). The Supercritical Water (SCW) has many advantages: water is a familiar and relatively safe heat transfer medium, it allows to work at high temperatures and it has a high specific enthalpy. Nevertheless, the SCW has a drawback: its physicochemical properties change with pressure and temperature inside of the supercritical region behaving more like gas or like liquid depending on the values of these variables. Bearing all this in mind, the main question is what will be the behavior of structural materials to degenerative processes like corrosion in this special environment? The austenitic stainless steel 316 L has been chosen as candidate material for the SCWR due to its optimum mechanical properties and its high resistance to corrosion processes. Moreover, this alloy has shown a good behavior after years of operation in the Light Water Reactors (LWR). The aim of this work is to gain more in-depth knowledge about the oxidation behavior of the 316 L in SCW and to study if there is a continuity of the oxidation mechanism from liquid water to SCW. Results from oxidation experiments of 316 L tested in liquid water at 350 ºC and 25 MPa, steam at 400 ºC and 10 MPa and SCW at 400 ºC and 25 MPa will be presented and discussed
Authors : Igor Andreiev
Affiliations : V. Bakul Institute for Superhard materials NASU
Resume : In this work are presented results of the investigation of geometrical shape distortion of blanks made of a tungsten_based alloy (W-Ni-Fe). Blanks are found to undergo a multistage form alter¬ation due to a liquidphase segregation in the material during its sintering in a multizone continuous fur¬nace. We have found the liquid phase flow in WNiFe alloys with contains of tungsten 89 % (weight) during their sintering in a variable temper¬ature field. As the tungsten_based alloy is moved through the furnace, the liquid phase migrates via pores from the head portion of the blank towards the tail one, thus resulting in a distorted blank geometry not only in the cross_section but also along the blank length. The head portion of the blank retains almost cylindrical shape, suggesting that the liquid phase in this portion migrates almost uniformly throughout the entire cross_section of the blank, and density of the blank head portion corresponds to that of an alloy with 8 wt % binder versus the preset value of 11 wt %; density of the tail portion corresponds to that of an alloy with 12 wt % binder, with¬out regard to the bead. The different edge effects (in terms of the form alteration and binder content) for the head and tail portions of the blank confirm that the distortion of the blank shape is mostly due to the temper¬ature gradient induced along the length of the blank as it travels through the furnace working area.
Authors : Liviu Duta1, A. C. Popescu1, C. Popescu1, B. Bita2, A. Husanu3, C. Himcinschi4, G. E. Stan3, V. Craciun1, Penka Terziyska5, A.Szekeres5
Affiliations : 1National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, RO-077125 Magurele, Romania; 2National Institute for Research and Development in Microtechnologies, 126A Erou Iancu Nicolae Street, RO-077190 Voluntari, Romania; 3National Institute of Materials Physics, 105bis Atomistilor Street, RO-077125 Magurele, Romania; 4Institute of Theoretical Physics, TU Bergakademie Freiberg, D-09596 Freiberg, Germany; 5Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, Sofia 1784, Bulgaria
Resume : Diamond Like Carbon thin films deposited on Si(100) and quartz substrates by Pulsed Laser Deposition (PLD) technique in vacuum or in methane atmosphere were investigated. The morphology, crystallinity, chemical bonding, hardness, adhesion, thickness and optical constants of the as deposited layers were investigated by Scanning Electron Microscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, pull-out and spectroscopic ellipsometry. The deposition gas pressure played a crucial role on films thickness, component layers ratio, structure and mechanical properties. Films synthesized in vacuum were a-C DLC type, while those obtained in methane were categorized as a-C:H DLC type. The deposited films were smooth, amorphous, and consisted of a mixture of sp3-sp2 carbon, with 50-90% sp3 content. Most of the films showed a bilayer structure a higher density layer at the interface with the substrate and a lower density layer on top, as confirmed by the ellipsometric data analysis. Their density and thickness directly influence the overall mechanical properties of the PLD deposited structures.
Authors : Tsukrenko V.V., Ruban А.К., Redko V.P., Dudnik Е.V.
Affiliations : Frantsevich Institute for Problems in Materials Science Krzhizhanovsky str.3, 03680, Ukraine, Kyiv-142.
Resume : Zirconia-based ceramics are characterized by high strength, fracture toughness, corrosion resistance, bioinertness and are perspective for orthopedic and dental restorative applications. The additive of CeO2 and Al2O3 increases resistance of Y-TZP ceramics to low temperature aging in the living organism environment. The microadditive of СоО provides colour contrast of ceramics. The physicochemical properties of nanocrystalline powders for designing of ceramics in the ZrO2Y2O3CeO2СоОAl2O3 system after heat treatment in the temperature range from 400 to 1300 °C with different amounts of CoO were investigated. XRD phase analysis, scanning electron microscope and BET measurements were used. It was found that the addition of Al2O3 increased the temperature of phase transformation of metastable F-ZrO2 to T-ZrO2 (F-ZrO2→T-ZrO2) whereas the microadditive of CoO decreased the begining of F-ZrO2→T-ZrO2 phase transformation up to 150 °C in comparison with composites in the ZrO2Y2O3CeO2 system. The traces of monoclinic phase of ZrO2 (M-ZrO2) were detected after aging of composites in the ZrO2Y2O3CeO2СоОAl2O3 system under hydrothermal conditions. Since the amount of M-ZrO2 after aging was less than 5 % the designed ceramics resistant to the aging in the humid environments and are perspective for the microstructural design of bioinert implants of various purpose.
Authors : Lesya Demchenko1, Sergey Sidorenko1, Anatoliy Titenko2
Affiliations : 1 Metal Physics Department, National Technical University of Ukraine Kyiv Polytechnic Institute, Kyiv, Ukraine, email@example.com; 2 Institute of Magnetism, Kiev, Ukraine
Resume : The diffusion saturation of iron-based alloys with nitrogen and carbon is widely used in industry for increasing of strength, hardness, wear and corrosion resistance of metal products operating in extreme environment. Inexhaustible and unrealized potentialities of such treatment are opened when applying it under strain and stress condition. The topical question in this direction is to clarify the diffusion and strengthening mechanisms during chemical-thermal treatment of strained alloys . The structure, phase composition and properties of surface diffusion layers formed in the preliminary deformed alfa-Fe, Fe-Cr, Fe-Ti, Fe-Cr-Ti, Fe-Ni alloys after diffusion saturation with N and C were studied. The diffusion layer is a combination of surface layers of different nitride phases, nanostructured eutectoid layer and a zone of internal saturation (alfa phase). Deformation considerably effects on the phase formation, structure, microhardness and thickness of nitrided layers. The microhardness test of nitrided layers has discovered the narrow intervals of deformations of 3-8 % and 20-30 % in which the considerable rise (in about 2 times) of microhardness of the surface diffusion layer after nitriding exist. The high microhardness of the diffusion layers results from the nitride phases formation.
Authors : V.Avetisian, A.Demchishin
Affiliations : Frantsevich Institute for Problems of Materials Sciences of NAS of Ukraine
Resume : Titanium nitride and TiN-based alloys with high wear and errosion resistance are perspective as coatings for various extreme applications. The most promising method of manufacturing of this types of coatings is ion plasma technology using cathode arc vacuum evaporation. This technology allows to create high ionized plazma flows for various gas atmospheres and vacuum and it essentialy influence upon the processes of synthesis and growth of metal and ceramic compounds on various kinds of substrates. Double and triple compounds of titanium nitride with Al, Cr, Zr additives had been produced using arc-vacuum evaporation on modified unit Bulat -3T. The structure and mechanical properties of these coatings had been investigated. It was shown that the main reason of essential hardness increasing for multilayered compositions is the formation of great number of boundaries between nanolayers and blocking of the moving of linear defects by these boundaries. Thus multilayered condensates have a great advantages in comparison with dopped and undopped single layered coatings
Authors : I.Valeeva
Affiliations : Frantsevich Institute for Problems of Materials Sciences of NAS of Ukraine
Resume : Measuring mechanical properties of materials is important for design and simulation of materials behaviors and evaluation of their functionality, especially for extreme environments. This work deals with measuring mechanical properties of constructional materials using spherical indentation data. Dimensionless expressions for the contact characteristics: contact load, contact area, mean contact pressure, approach of solids, and mean (over the area of the contact) deformation directed along the applied load are based on the finite element simulations. Approximations for dimensionless contact characteristics are obtained in a wide range of material properties: reduced elastic modulus of contact pair, yield strength of specimen material, work-hardening exponent of material. These approximations are also found for hard materials with low ratio of elastic modulus to yield strength. This approach is applied to constructional materials that behave differently in tension and compression
Authors : Kalinichenko A.I., Perepelkin S.S., Strelnitskij V.E.
Affiliations : National Science Center "Kharkov Institute of Physics and Technology"
Resume : The opportunity of forming of nanometer-sized through hole in the metal film by heavy ion with energy from the range of elastic loss domination is theoretically investigated. It is assumed that the following conditions have to be met for origination of through hole: 1) molten channel is formed throughout the film thickness h; 2) the total time of pressure stabilization τs ~ 2R/s and melt ejection from the channel Te~ h(p/2vK)1/2 should not exceed the cooling time tT ~ R2/4κ of the channel with radius R. Here s is the sound velocity, ρ is the mass density, K is the bulk modulus, κ is the phonon diffusivity and v is the specific dilatation of film material during melting. The minimal cross size 2Rmin of the channel providing melt ejection is equal to 16κ/s in order of magnitude. Simulations of cascades of excited atoms generated by Xe+ ions with energy of 200 keV in the gold film of thickness h = 50 nm were performed using package SRIM2008. They have shown the possibility of formation with probability w ~ 0.01 near the ion path through the entire thickness of the film of continuous overheated region satisfying the above criteria. The conclusions are in accordance with the experimental data
Authors : L.R.Vishnyakov, V.A.Kohany, A.V.Neshpor, I.N.Kohanaya, Yu.M.Vasilenkov
Affiliations : Scientific center "Composite materials"
Resume : Fire safety of wind power units placed in offshore zones depends essentially upon perfection of the lightning protection system of turbine blades. Since the storm activity in the offshore zones is characterized by multi-vector behavior of lightning strikes, and the length of the blades is large and can exceed 80 meters and more, it becomes apparent that special lightning capture coatings are necessary for reliable work. Knitted and soldered special copper netting molded on the surface of carbon plastic composite during the process of wind blade production had been proposed. Unlike other types of lightning receivers proposed meshed lightning receiver has dissipative properties and ensure not only effective removal of electric charges and heat from lightning place but also decreasing of carbon plastic thermal degradation due to evaporation of low-melting solder and straightening of loops Electric charges trapped on lightning receiver discharged using special earthing tire produced from similar mesh. The results of practical tests of such kind of wind blades had been presented
Authors : Braude I.S., Gal'tsov N.N., Geidarov V.G., Kirichenko G.I., Abraimov V.V., Lototskaya V.A.
Affiliations : B.I.Verkin Institute for Low Temperature Physics and Engineering of NАS of Ukraine
Resume : Recently the polymers has become an avalanche process, due to their unique properties . Particularly, polyimide materials (type PM-A, kapton H) are are widely used in space technics as a basis thermocontrol coverings of SV, as solar reflectors and aerials, electroinsulation materials, materials of fastening of SV devices and other elements SV. However, because of the complex molecular structure of some questions there is still no clear answer. This is due to the fact that these objects are composed of high molecular weight randomly entangled and intertwined molecules. At various external influences they begin to transform, in some cases forming independent structural formations. For X-ray study of such substances gives typical amorphous bodies X-ray scattering pattern, characterized by short-range order. This paper presents the results of a study by X-ray diffraction, polyimide type PM-A Group V  subjected to uniaxial tension (elastic deformation), bulk compression (by cooling to low temperatures) and their joint impact. X-ray diffraction studies were carried out on a DRON-2.0 with Cu-Kα anode and Ni filter system with collimation slits. Measurements were carried out in the angular range 2θ = 4 - 70о. The samples, which conducted the study, is a molecular crystal in which there is no long-range order of the position of the molecules. In all the observed diffraction patterns there is a diffuse halo. The reason for this result is, in first approximation, a linear PM-A A can be explained by different mechanisms of ordering of long molecules under uniaxial and bulk loading.
Authors : Aleksandra Kedzierska(1)(2), Paulina Wiecinska(1), Pawel Falkowski(1), Mikolaj Szafran(1)
Affiliations : (1)Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland; (2)Laboratory of Advanced Ceramics, Institute of High Pressure Physics PAS, Warsaw, Poland
Resume : In the field of materials engineering, scientists from all over the world are continuously developing new materials for challenging applications in aerospace, medicine, transportation or manufacturing, to mention the most important. Ceramic materials (single- or multiphase) are promising materials to fulfil these applications. On the one hand ceramic materials have many beneficial properties such as high hardness, chemical and temperature resistance or excellent wear resistance. Conversely, properties like fracture toughness, thermal shock resistance or Weibulls characteristics still need to be improved. One of the methods to further improve properties of ceramic materials is incorporation of nano- and micro- metal particles into their structure. These new materials, named ceramic-metal composites, have shown better behavior in the above mentioned areas, depending on type, size and volume fraction of the particular metal particles. In present work the alumina tungsten composite was formed by slip casting method. The addition of metal phase causes changes in viscoelastic properties of water-based ceramic slurries what has been examined by Authors. Among particles appears the heteroflocculation effect which results in good adhesion between ceramic and metal phases. The ceramic-metal interaction is crucial for improvement of some properties, like fracture toughness. This work was financially supported by National Science Center of Poland (grant number 2014/13/N/ST5/03438).
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Authors : G. Socol1, D. Craciun1, G. Dorcioman1, N. Stefan1, V. Grumezescu1, V. Craciun1, D. Cristea2, L. Floroioan3, M. Badea4, D. Pantelica5, P. Ionescu5
Affiliations : 1National Institute for Lasers, Plasma and Radiation Physics, Măgurele, Romania; 2Materials Science Department, Transilvania University, Brasov, Romania; 3 Fac Elect Engn & Comp Sci,Transilvania Univ Brasov, Brasov, Romania; 4Faculty of Medicine, Transilvania University, Brasov, Romania; 5Horia Hulubei National Institute for Physics and Nuclear Engineering, Măgurele, Romania
Resume : Most of the problems associated with metallic implants occur at the metal-body interface. To improve the mechanical and chemical stability of this interface and promote bone growth, the implants surface is usually coated with a biocompatible thin film. We deposited ZrN, ZrC, TiN, and TiC films on Ti implants by the pulsed laser deposition technique to investigate their properties. The films were deposited at room temperature on mirror-like polished or textured Ti substrates using a KrF laser under CH4 or N2 atmosphere. The mechanical properties of the films were characterized by nanoindentation, scratch and wear tests. The structural properties were obtained from grazing incidence X-ray diffraction and X-ray reflectivity investigations. The chemical composition was measured by Rutherford backscattering spectrometry. Electrochemical measurements involving corrosion and electrochemical impedance spectroscopy studies were carried out in physiological solutions to investigate the chemical stability of the titanium, bare or covered with the PLD grown films and to compare their performance. The dependence of their corrosion resistance parameters on time was inferred and the involved electrochemical parameters were estimated by fitting the experimental data via equivalent electric circuits. The results clearly showed that the deposition of coatings resulted in more stable surfaces that were less affected by corrosion and exhibited better mechanical properties than bare Ti.
Authors : A.V. Vasin, A.V. Rusavsky, A.N. Nazarov, V.S. Lysenko, V.P. Kladko, O.Yo. Gudymenko, C. Nouveau, S.P. Starik
Affiliations : Lashkaryov Institute of Semiconductor Physics, NASU,Kiev, 03028 Ukraine CER Arts et Métiers ParisTech, Rue Porte de Paris, F-71250, Cluny, France , Bakul Institute of Superhard Materials NASU, 2 Avtzavodskaya str., Kiev, 04074 Ukraine
Resume : Amorphous silicon carbide films were deposited on silicon substrates at 200 °C by RF-magnetron sputtering of SiC target in argon or argon/methane gas mixture. Hydrogenated and non-hydrogenated layers were examined in terms of density, mechanical stresses, wear/corrosion resistance and friction coefficient. Density of the films was varied in range of 1.6-3.4 g/cm3 by varying magnetron discharge power and working gas composition. FTIR and Raman spectroscopy identify the structure of as-deposited films as amorphous SiC matrix with incorporated carbon nano-clusters. After the deposition the samples were thermally treated in argon or oxygen. As-deposited films exhibited compressive stresses that were partially relaxed after annealing in pure argon. Annealing in oxygen resulted in evolution of compressive stresses into tensile. It was demonstrated that oxidation resistance as well as mechanical stresses directly correlate with density of the films. Structural model of stress evolution in oxidized material and possible way of stress engineering in a-SiC:H films by thermal treatment in oxygen are proposed.
Authors : A. Rizzo, D. Valerini, L. Mirenghi, F. Di Benedetto
Affiliations : ENEA - Italian National Agency for New Technologies, Energy and the Sustainable Economic Development, Technical Unit for Materials Technologies - Brindisi Research Center, S.S. 7 Appia km. 706, 72100 Brindisi, Italy.
Resume : Extreme conditions/environments of temperature, wear and corrosion easily occur in a very wide number of applications, from energy (concentrating solar power systems, thermoelectric devices, oil and gas plants, etc.), to transportation (aeronautics and aerospace, marine transportation, etc.) and manufacturing (high-speed machining, cryogenic machining). Consequently, the use of protective coatings in these technological fields has a strong importance for the industrial economy. The aim of the present work is to produce the ZrN coatings deposited by Reactive Bipolar Pulsed Dual Magnetron Sputtering (BPDMS) and to study the relationships between the target-power and the plasma parameters and their impact on the film growth. In particular, the effect of BPDMS technique on chemical, structural and mechanical properties of the deposited ZrN films was pointed out. XPS characterization inside the ZrN films has revealed the presence of stoichiometric ZrN and a uniform concentration profile along their thicknesses. At highest power (2 kW) the metallic component was detected on Zr3d high resolution spectra beside the nitride comnponent, while at lowest power (0,5 KW) there is no metallic component but the nitride is a mixture of ZrN and Zr3N4, in the following percentage 70:30. The oxygen level is well below the 2 at. %. For BPDMS with 80 kHz and increasing duration of the duty cycle from 20 to 50 % the hardness increases from 20 to 32 GPa, respectively.
Authors : M. Parco Camacaro(1), I. Fagoaga(1), O. Grigoriev (3), L. Silvestroni (2), I. Neshpor(3)
Affiliations : 1-Tecnalia, Spain; 2-Institute of Science and Technology for Ceramic of Council of National Research of Italy; 3- Frantsevich Institute for Problems of Materials Sciences of NAS of Ukraine
Resume : Ceramic powders based on ZrB2, ZrB2-WC and ZrB2-MoSi2 produced by IPMS (Ukraine) and CNR (Italy) have been deposited by plasma detonation on C/C substrates by TECNALIA (Spain). Coatings have been directly sprayed on C/C substrates without intermediate layers. Various powder granules size and set-ups of deposition have been tested and the structure and phase composition of the coatings have been determined. The mechanical properties of the best coatings have been measured by indentation method. Comparative ablative testing with HHO flame of the coatings have been carried out. Preliminary HHO jet ablative tests revealed that with suitable powder treatment, ZrB2-based coatings can be effectively applied to C/C substrate, thus improving their oxidation resistance.
Authors : P. Sharma and J. Dutta Majumdar
Affiliations : Indian Institute of Technology Kharagpur
Resume : In the present study, a detailed investigation of the kinetics and mechanism of hot corrosion of the thermal spray deposited nickel based boride dispersed coating on AISI 304 stainless steel has been undertaken in a 70% NaSO4+30% NaCl molten salt media in the temperature range between 700oC to 900oC. Thermal spray deposition has been carried out on sand blasted AISI 304 stainless steel substrate by flame spraying and HVOF spraying techniques using nickel based hard faced alloy (Ni-68.4Cr-17B-3.9Si-4.9 Fe-5.8) as precursor powder. A detailed microstructural investigation of flame sprayed layer showed the formation of Ni3B precipitates in equiaxed -Ni grains. HVOF deposition led to development of Ni3B and Cr2B dispersion in meta-stable amorphous -Ni matrix. Hot corrosion behaviour was studied in a 30% NaCl+70% Na2SO4 molten salt media under cyclic heating with a cycle duration of 3 hrs for a maximum no. of 18 cycles. Followed by hot corrosion, a detailed investigation of microstructure and phases of the corroded surfaces (top surface and cross-section) were carried out by scanning electron microscopy and X-ray diffraction techniques to understand the mechanism of hot corrosion. Finally, the mechanism of hot corrosion has been proposed following a detailed thermodynamic analysis of phase formation schedule and correlating it with the characteristics of the hot corroded surface.
Authors : Ching An Huang, Chin Huo Chuang
Affiliations : Chang Gung University
Resume : Cr-C-Al2O3 deposits with different Al2O3 concentrations were successfully prepared on a Cu substrate using Cr3+-based electroplating baths. The microstructures of the Cr-C-Al2O3 deposits were examined using optical, scanning and transmission electron microscopes. The hardness values, the corrosion and wear resistance of the Cr-C and Cr-C-Al2O3 deposited specimens were evaluated. Based on the experimental results, the hardness values of the Cr-C-Al2O3 deposits increased with increasing Al2O3 concentration in the electroplating bath. According to our microstructure study, Al2O3 nanoparticles were uniformly distributed within the Cr-C deposits after electroplating in a Cr3+-based plating bath. The wear and corrosion resistance of the Cr-C-deposited specimens could be noticeably improved by adding Al2O3 nanoparticles to the deposit. This result is attributed to a reduced number of cracks in the Cr-C deposit after the addition of Al2O3 nanoparticles. The Cr-C-Al2O3 deposited specimens, which were prepared in a plating bath with an Al2O3 concentration of 50 gL-1, had a relatively high corrosion and wear resistance compared to the other specimens. The above-mentioned results will be discussed in this study.
Authors : C. Rentrop , H. Slot, H. van Bracht, E. van der Heide, M. Le Feber
Affiliations : TNO
Resume : Future growth in wind energy depends heavily on the economic feasibility of new offshore capacity. Locations at sea give rise to more demanding environments, e.g. due to water droplet laden winds. Erosion of the leading edge of the turbine blades by droplet impingement wear, can easily reduce machine power output and eventually compromises the integrity of blade surfaces. Coatings are currently used for on shore locations to increase the erosion resistance, yet the life of such coatings in more demanding environments cannot be predicted accurately. The talk summarizes the state of the art in droplet impingement erosion modelling and gives an overview of experimentally validated building blocks of erosion models that can be used to predict the life of the leading edge of coated wind turbine blades. From the reviewed work it is concluded that surface fatigue, as nucleating wear mechanism for erosion damage, can explain erosive wear and failure for brittle and for ductile materials as well. Novel developments to improve the coating stability are discussed as well. This includes alteration of success demanding properties like density, toughness and strength by nanostructuring of the wind turbine coating. This is created by introduction of anisotropic nanoparticles resulting in improved impingement resistance at extremely high nanoparticle loading (20wt.%). Also the introduction of self-healing additives is discussed in order to create a total thermoplastic wind turbine concept.
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Authors : M. Pelletta, P. Siffalovic, M. Hodas, Y. Halahovets, K. Vegso, M. Jergel, I. Matko, Z. Zaprazny*, D. Korytar*, J. Keckes**, Thomas Dick***, and E. Majkova
Affiliations : Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 84511, Bratislava, Slovakia; *Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104, Bratislava, Slovakia; ** Department of Materials Physics, Montanuniversität Leoben, Jahnstrasse 12, 8700 Leoben, Austria; *** tortuetec GmbH, Goldschlagstrasse 172, 1140 Wien, Austria;
Resume : The single-point diamond processing (SPDP) technology can be extended to cost-effective production of the X-ray diffractive and reflective optics. We present two examples of Ge-based X-ray optics: a) SPDP channel-cut monochromator based on asymmetric/symmetric diffraction and b) multilayer mirror (Mo/Si) deposited on SPDP Ge substrate. We show that the final roughness of Ge surface after SPDP can be lower than 0.5 nm (RMS). On the other hand, SPDP creates a sub-surface damage of the crystal lattice, forming a 30 nm thick amorphous Ge layer as verified by the transmission electron microscopy. To increase the Ge surface chemical stability, we deposited a 5 nm thick B4C layer. The passivated Ge surfaces exhibit enhanced resistance against oxidation in the presence of the ionizing X-ray radiation. The X-ray photoelectron spectroscopy, atomic force microscopy, imaging ellipsometry and confocal micro Raman spectroscopy were employed to study the impact of the ionizing X-ray radiation on the surface quality and sub-surface damage of the bare and protected Ge surfaces. The deposition of multilayers for the soft and hard X-ray reflective optics requires superpolished surfaces with a roughness below 0.3 nm RMS. The conventional surface form shaping and polishing technology to produce superpolished substrates is time-consuming and expensive. We show that SPDP can be used to fabricate a free form surfaces suitable for deposition of the reflective X-ray optics. Here, a thick B4C buffer layer was deposited prior to multilayer deposition in order to lower the roughness spectrum at high spatial frequencies. Using the X-ray reflectivity and diffuse scattering we compare the Mo/Si multilayer mirrors deposited on a conventional superpolished substrate and on the SPDP figured substrate.
Authors : O. Grigoriev (1), L. Silvestroni(2), I. Neshpor(1)
Affiliations : 1-Frantsevich Institute for Priblems of Materials Sciences of NAS of Ukraine, Kiev,Ukraine; 2-Institute of Science and Technology for Ceramics of National Research Council of Italy, Faenza, Italy
Resume : The oxidation behavior of ZrB2-based ultra-high temperature ceramics with different sintering additives at temperatures of 1250°C, 1550°C, 1650°C in the air, during 15 min. has been investigated.The ceramics have been produced by hot-pressing and vacuum hot-pressing methods. On the most resistant composites, cyclic oxidation was performed in the same furnace at temperature of 1650°C, so that the best UHTCs underwent 3 cycles at 1650°C for 15 minutes each. On these specimens, the microstructural modifications induced by oxidation were evaluated by x-ray diffraction and by scanning electron microscopy coupled with energy dispersive x-ray spectroscopy on the surfaces and fractured cross-section. Oxidation tests performed in a bottom-loading furnace at 1650°C for 15 minutes and repeated 1-3 times revealed that ceramics obtained by vacuum hot pressing showed higher resistance to oxidation compared to ceramics obtained by hot pressing, possibly because of higher final density, and the best results are achieved when ZrB2 is sintered with simultaneous MoSi2 and CrB2. The investigations had been supported by FP7 project LIGHT-TPS
Authors : Uvarova I., Kud I. , Ieremenko L. , Likhodid L. , Zaytkevich D.
Affiliations : Frantsevich Institute for Problems of Materials Sciences of NAS of Ukraine
Resume : The main characteristics that determine the use of refractory materials under extreme conditions at high temperature in aggressive media are heat and oxidation resistances. The aim of the work was to study process of oxidation of compact MoxCrySi2 samples in air during heating 800-1600oC under thermal shock loading. The furnace SNOL-1,8.3.1,8/14-ТRP08-ТP working at 800-1200оС and optical furnace «URAN-1» at 1600°С were used for tests of heat and oxidation resistances in air. The sample surface after testing was examined by scanning electron microscopy (SEM) on a microscope «Superprobe-733» as well as by scanning probe microscope «Solver Pro-M». As the obtained results for high temperature oxidation resistance (change in mass due to oxidation, %) were established that the MoxCrySi2 samples have better oxidation resistance than that of the MoSi2 samples. In particular, the oxidation resistance of the solid solutions Mo0.6Cr0.4Si2 and Mo0.9Cr0.1Si2 was two and ten, respectively, times that of the MoSi2 samples. Microscopic examination revealed that MoSi2 samples (whose maximal degree of oxidation during the test was 0.0572 %) were characterized by the presence of significant defects in the form of branched deep 25 mcm wide cavities and a microscopic net of to 1 mcm tracks. The microscopic examination of the Mo0.9Cr0.1Si2 sample surface after high temperature tests did not reveal any mechanical defects. The surface morphology indicates formation of a continuous glasslike protective film on the basis of complex silicides of molybdenum and chromium, which preserves its strength in the low temperature region. The high oxidation resistance (+0.0094 %) of the Mo0.9Cr0.1Si2 samples under the hard test conditions is explained by formation of a self-passivating protective film which preserves its properties under rapid heating/cooling. Consequently, the obtained results made it possible to conclude that the developed solid solutions MoxCrySi2 possess higher properties (heat and oxidation resistance) compared to MoSi2. Hence the solid solutions Mo0.9Cr0.1Si2 and Mo0.6Cr0.4Si2 can be recommended for application as oxidation-resistant materials at high temperatures, namely to 1600°С and 1400°С, respectively.
Authors : T. Konstantinova, O. Gorban, I. Danilenko
Affiliations : Donetsk Institute for Physics and Engineering named after O.O.Galkin NAS Ukraine
Resume : Possibility increasing of nanocomposites property as it known is limited by the problem a uniform distribution of the nanopowders in matrix. In this work we propose new approach to design of oxide ceramic-ceramic nanocomposites what substantially different from the method of mechanical mixing components of the composite. The first step of this approach is developing the technology of multicomponent nanopowders. The developed technology ensures the soft agglomerates, specified size and allows entering low concentrations metal oxide dopants by modification of cation sublattice. It is established on the example of zirconia that even a slight amount of chromium, aluminium, copper and oxides leads to a significant change of the nanopowders and ceramics properties The second step of creating nanocomposite is the high pressure compacting process. The behaviour of dopped nanoparticles under high pressure is difference in comparison with nondopped particles due to change of its surface state and because compacting process is demanded of optimization in the level of high pressure. The third step is the more important, this is sintering. In ternary systems detected competition between components of composites lead to an increase in the concentration of the cation dopant on the surface of zirconia nanoparticles. Heating provides modification of nanoparticles and granules surface by doping of cations, and at determine temperature on the boundaries of grains may be oxide precipitations which ensure subsequently forming uniformly finely distributed filler phase in the matrix. Obtained in this way nanocomposite materials have increased by 1.8 times and fracture toughness increased 2 times resistance to low temperature degradation.
Authors : L. Kernazhitsky (1), V. Shymanovska (1), V. Naumov (2), P. Smertenko (2), V. Skryshevsky (3)
Affiliations : (1) Institute of Physics, (2) Institute of Semiconductor Physics, (3) Institute of High Technology Taras Shevchenko National University
Resume : Nanostructured titanium dioxide (TiO2) is one of the most promising materials in the family of metal oxides semiconductors that characterized by unique properties and capabilities for various energy and environmental applications, particularly, in extreme terrestrial or extraterrestrial environments. To expand TiO2 photocatalytic activity from the UV to the visible range of solar spectrum, TiO2 usually modified with transition metals. However, different nanostructures prepared by different methods often show different characteristics [L. Kernazhitsky et al. (2013) J Solid State Chem 198:511]. We have prepared a set of high-purity fine-dispersed TiO2 nanopowders in single-phase anatase and rutile crystal forms, synthesized by thermal hydrolysis and doped with different transition metal cations Cr3+, Fe3+, Co2+, Cu2+ by the surface adsorption. Pure and doped TiO2 samples were studied by electron microscopy, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, optical UV-VIS absorption, photoluminescence, and electrical C-V measurements. According to structural and morphological analysis, average sizes of nanocrystallites were 10-15 nm for anatase and 15-30 nm for rutile; specific surface areas were 15-30 m2/g for rutile and 100-120 m2/g for anatase. The band gap values varied between3.25-2.9 eV for anatase and 3.0-2.9 eV for rutile. Electronic, optical and photocatalytic properties of pure and doped TiO2 structures are analyzed in details in the light of the data obtained by various experimental characterization techniques. Mechanisms of injection transport are discussed in comparison with available models. The results demonstrate a clear difference between doped and undoped TiO2 compounds. Research is in progress. Support of the FP7 project FOTONIKA-LV is gratefully acknowledged
Authors : 1-Ievgen Solodkyi, 3- Hanna Borodianska,2- Yoshio Sakka, 5-Petre Badica, 4-Oleg Vasylkiv
Affiliations : 1-National Technical University of Ukraine KPI; 2- National Institute for Materials Science, Tsukuba, Japan; 3- Frantsevich Institute for Problems in Materials Science, Kiev, Ukraine; 4-Nanyang Technological University, Singapore; 5-National Institute of Materials Physics, Romania
Resume : Boron suboxide (B6O) is a light weight material and has promising physical and chemical properties such as high hardness, high thermal conductivity, good chemical inertness, and excellent wear resistance. However, pure material with a high crystal quality and high oxygen doping level (i.e. x=1 in B6Ox) is difficult to fabricate by ambient pressure methods in contrast to more successful high pressure methods. Apart from these problems addressed in the previous paragraph with phase purity and quality, B6O is also a difficult-to-sinter material. Pressure assisted methods moderate pressures (usually less than 100MPa), hot pressing (HP), and spark plasma sintering (SPS) were applied to obtain dense samples. In all these situations, B6O powders were used and they were prepared before sintering, i.e. processing was made in two separate steps (ex-situ route). In this work we propose and demonstrate formation in one processing step (in-situ route) of dense single phase B6O ceramic of good quality by reactive SPS applied on mixtures of B2O3 and amorphous boron (aB). The Rietveld refinement of the XRD patterns indicates that the oxygen occupancy of B6Ox is reasonably high at x=0.89(99). As-prepared B6O dense ceramic has Vickers hardness (36.7±1.2 GPa) and fracture toughness (K1c=4.2±0.15 MPa.m1/2) comparable with the highest values reported in literature for the bulks obtained by processing routes of already reacted B6O powders (ex situ routes).
Authors : K.Agroui (a), G.Collins (b) and I.Ziane (a)
Affiliations : (a) Semiconductors Technology for Energetic Research Center (CRTSE) 2, Bd. Dr. Frantz Fanon, BP 140 Alger 7 Merveilles, Algiers, (b) Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
Resume : The crystalline silicon photovoltaic (PV) module is a laminate assembly composed essentially of polymer materials with widely varying thermal properties. The properties of these materials are important factors influencing the performance and reliability of PV modules following exposure to external mechanical stress. In general, encapsulant polymers are designed for a certain range of operating temperatures where they possess desired properties; it is therefore suitable that the polymer?s glass transition region is outside the range of operating temperatures. Generally, the region between 0?C and -40?C is called the glass transition region and the selection of encapsulant materials is based on very low glass transition temperature (Tg). Low temperature phase transition behavior in polymers is important, because this transition has a strong impact on materials mechanical properties and PV module encapsulation reliability. Poly-Vinyl-Butyral (PVB) is increasingly assuming the leading role among alternative encapsulation materials for solar cells as the alternatives to Ethylene-Vinyl-Acetate (EVA). The aim of this work is to analyze the changes in the relevant thermal behavior of PVB encapsulant material as a new emerging material over a broad temperature around Tg by DSC, TSC, and DMTA thermal analysis. Special interest will be focused on the specific TSC relaxation parameters like activation energy and relaxation frequency determination by using the initial rise method.
Authors : I.Bilan.,L.Chernyshev.,N.Fedorova
Affiliations : Frantsevich Instittute for Problems of Materials Sciences of NAtional Academy of Sciences of Ukraine
Resume : Two classes of materials used for reused space apparatus had been analysed. First one - is metallic materials on the base of Ni and Nb. Second one - is ultra high temperature ceramics on the base of sirconium diboride. Their service parameters and perspectives of their applications had been discussed
Authors : Oleksandr Povstyanoy, Viktor Rud, Viktoriya Shiberko
Affiliations : Lutsk National Technical University, Ukraine
Resume : Nowdays, highly competitive market puts forward great demands to increase efficiency and reduce costs in the manufacturing sector. Computer simulation modelling is widely used as a successful tool for design and analysis of the finished product. Distinguished feature of the most common technologies of modern materials science is the use as a primary feedstock, materials in a granular state. It's not only well-known processes of powder metallurgy, but also powder coating, nanotechnology, etc Creation of new materials from powders with predetermined properties put forward new demands for research and solving of technological tasks. Filling processes, despite its simplicity, depends on particle size distribution of charge, physical and mechanical characteristics of powders, filling method of a volume, dimensions of product and other. Investigation of filling process is possible by several ways: by a natural experiment, computer simulation modelling and etc. Analysis of the modern state of modelling studies in powder metallurgy indicates on a clear trend in description of properties of physical processes on the basis of models of random packing of particles. In Lutsk NTU (Ukraine) was developed a series of computer-simulation models of particle packing for monodispersed and polydispersed case of filling powders.
Authors : V.Zinchenko(1),E.Chygrynov(1), O.Mozkova(2)
Affiliations : (1)A.V. Bogatsky Physico-Chemical Institute of NAS of Ukraine; (2)State Enterprise for Special Instrument Making "Аrsenal"
Resume : Film-forming materials (FFМ) are used as initial substances for obtaining coatings by so-called 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 ZnS-Ge, evaporating congruently at rather low temperatures. Here we represent the evaporation mechanism in vacuum and condensation on a substrate of this material. It combines in itself the features of both PVD, and CVD processes. The calculated value of conditional temperature (Ta=TP≈1.33Pa) for a 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 and to expand domain of transparency of Ge up to the border of a visible range of a spectrum. The materials evaporating and condensed in a similar way are named CVD-composites. 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. In it surplus of the sulfidizing agent, Sb2S3 is eliminated by processing by an additive of disperse Ge. By the way Sb2S3-Ge composite makes it possible obtaining coatings with much higher mechanical durability in comparison with a coating produced from pure Sb2S3. Other CVD-composites as FFМ on the basis of binary compounds are investigated also, namely: ZnSe-Ge, Sb2Se3-Ge, In2Se3-Ge, EuS-Ge, EuSe-Ge, ZnO-Ge, GeO2-Ge, and SnO2-Ge. Their considerable part has shown also high level of optical and operational parameters of coatings. It is supposed to expand circle of FFМs of CVD-composite type, using complex oxide as one of components that allows hoping that it should be possible to deposit nano-composite coatings with electro-conductive properties in a soft technological mode.
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Authors : O. Smorygo 1, A. Marukovich 1, V. Mikutski 1, A. Ilyushchanka 1, A. Pramono 2
Affiliations : 1 Powder Metallurgy Institute, Minsk, Belarus 2 Research Centre for Metallurgy and Materials, Indonesian Institute of Sciences (LIPI), Kawasan Puspitek 470, Serpong 15314, Banten, Indonesia
Resume : Cellular vitreous carbons (vitreous carbon foams) have been finding extensive applications in various industries as the aerospace super-light components, high-temperature components for vacuum technique, flow through electrodes, catalyst supports for the electrocatalyst processes, bioscaffolds. The large area of very different potential applications is explained by outstanding combination of properties of vitreous carbons: stability in the air-free atmospheres at temperatures of above 2000oC, intertness towards acids and alkali, high theramal- and electric conductivity, low thermal expansion, and reasonable strength0to-weight ratio. Two alternative methods were used to synthesize the cellular vitreous carbons: the sacrificial template method and the polyurethane foam replication method. Phenolic and epoxy resins were used as the carbon precursors; the precursors were converted to disordered (glassy) carbon by pyrolysis in the nitrogen flow at 1000-1100oC. No remarkable microstructure differences were stated depending on the precursor type and the synthesis method. Materials exhibited excellent resistance in aggressive solutions: HF, H2SO4, NaOH, H2CrO4. The cellular carbon pore structure and properties (mechanical strength, modulus, electric- and heat conductivity, hydraulic permeability) were dependent on both the synthesis method and porosity. Approaches to control final porosity of the cellular carbons were studied. Support of Belarusian Republican Foundation for Fundamental Research (Project T13INZ-001) is gratefully acknowledged.
Authors : Bechke К.V.; Sanin А.F.
Affiliations : Gonchar Dnepropetrovsk National University, Ukraine
Resume : Construction materials for aircraft and space technique must possess high mechanical properties, in particular by the yield strength, plasticity, specific strength. The dispersion-hardened aluminium alloys, which promote hardening mainly by structural factors, occupy highly important place among these materials. Dispersed strengthening was studied at this work on aluminium alloy additionally containing 1% Fe. For receiving oversaturated solid solution of iron in aluminium it is necessary to use the cooling rate at crystallization more than 105 106 К/s. When melt is water-atomized, the particles are cooled down at 106 K/s. As metal droplets are crystallized, an abnormally oversaturated solid solution of iron in aluminum forms and a superfine intermetallic phase may develop in subsequent treatment. Iron aluminides in pressed parts are formed at heating to the temperatures 4500С. Particles of indicated phases are evenly distributed over the material volume. After hot working the high dislocation density is formed in the alloy structure. The cellular substructure whose boundaries are fixed by superfine particles forms after quenching. Exactly this structure ensures dispersion hardening. Stress-strain properties of received alloy: σВ = 435-450 МPа, δ = 8,6-10,8 %.
Authors : Oleksandr Povstyanoy, Viktor Rud', Tetyana Gal'chuk
Affiliations : Lutsk National Technical University, Ukraine, Lutsk, Lvivska, 75, zip code 43018
Resume : The purpose of work consists in a construction most close to the real process of grinding down, mathematical model. This model will allow: to define the optimum modes of work of bullet mill; to foresee descriptions of products of grinding down on the known descriptions of entrance material and modes of work of mill. It is of interest to trace an experimental way after the changes of grinding down of remain depending on his amount in a mill. Grinding down behaves to the number of basic technological processes of utilization of polishing wastes. An operation this grinding down is a process of mechanical destruction of particles of powders of steel of ШХ15, intended for the maximally possible grinding down of initial particles and giving them of regular form. Adjusting of cycle of grinding down is taken to providing of burst performance of mill at the set craniometrical description of the ground up class. The results of all of the subsequent processing of product depend from the high-quality quantitative indexes of grinding down, foremost, such as, homogeneity of properties on a volume, productivity of process of receipt of the finished products. Consequently, object of mathematical design is a bullet mill in an aggregate with the process of classification. At a design the followings assumptions are accepted: division of particles in a mill and on control riddles accepted even on all of surface, efficiency of classification is the size of permanent and doesnt change in time. The algorithm of decision of mathematical model includes determination: differential equalization determining kinetics of process of grinding down, and equalization of financial balance on mass on the stage of classification.
Authors : (1)I.Bilan.(2) D.Avetisian
Affiliations : (1)Frantsevich Institute for Problems of Materials Sciences of National Academy of Sciences of Ukraine (2) Taras Shevchenko Kiev National University
Resume : The place of thematic topic connected with materials and coatings to be used in extreme environments in new Horizon 2020 calls of three thematic priorities Nanomaterials, nanotechnologies and new production technologies, Energy and Space had been analysed. The main technical requirements and areas of their applications had been discussed
Authors : K.N. Ivanenko
Affiliations : Chernigiv National Technological University
Resume : This work is devoted to the development and scientific ground of the complex system of security resource saving and technogenous safety of welding construction exploitation in ecologic dangerous production with receiving of integrated natural-guarding effect. It is shown, that the rational choice of technology welding (with the adjustable cooling, steel 09G2FB) let a possibility to decrease the integral indexes of contamination environment: soil (Zc), air (ICA), water (ICW), and to increase a corrosion resistance. It is offered the effective coefficient of a resistance of welded joints to a hydrogen degradation, a cracking, a fatigue The prospects of universal manners of decreasing ecodanger of the natural and technological mediums introduction of effective synergist metallochelating composition on the secondary raw materials (production and consumption waste non-condition on the useful life pharmpreparations) and the modificated them the protection coatings, durable in conditions of cooperated influence of the aggressive mediums and electromagnetic fields have been established. It is permissed in time to prevent risk of technogenous accidents.
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