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Deposition of Fluorocarbon Plasma Polymer Nanoparticles and their Basic Properties
Serov, Anton; Choukourov, A.; Artemenko, A.; Kuzminova, A.; Biederman, H.; Hrabovský, Milan
2015 - English
Fluorocarbon plasma polymer nanoparticles have been fabricated using gas aggregation cluster source (GAS) equipped with a planar magnetron with PTFE target. A beam of nanoparticles 20 – 200 nm in diameter was generated. Fluorocarbon nanoparticle films have shown very good water repellent properties. Films immersed in ethanol for two hours exhibited excellent stability that was also good in case of water. Measurements using a deflection system showed the presence of both neutral and charged nanoparticles.
Keywords:
poly(tetrafluoroethylene); magnetron sputtering; plasma polymerization; superhydrophobic
Available at various institutes of the ASCR
Deposition of Fluorocarbon Plasma Polymer Nanoparticles and their Basic Properties
Fluorocarbon plasma polymer nanoparticles have been fabricated using gas aggregation cluster source (GAS) equipped with a planar magnetron with PTFE target. A beam of nanoparticles 20 – 200 nm in ...
Nanostructuring of solid surfaces by discharge-pumped xuv laser source
Schmidt, Jiří; Štraus, Jaroslav; Koláček, Karel; Frolov, Oleksandr
2015 - English
The experimental results of interaction of focused XUV laser beam (wavelength 46.9 nm) with Polymethylmethacrylate (PMMA) and GaAs samples will be presented. Proximity-standing golden grid showed on naturally-generated diffraction pattern that direct nanostructuring is possible
Keywords:
XUV laser; laser ablation; diffraction pattern
Available at various institutes of the ASCR
Nanostructuring of solid surfaces by discharge-pumped xuv laser source
The experimental results of interaction of focused XUV laser beam (wavelength 46.9 nm) with Polymethylmethacrylate (PMMA) and GaAs samples will be presented. Proximity-standing golden grid showed on ...
Measurements with Atomic Beam Probe Diagnostic on the COMPASS Tokamak
Háček, Pavel; Berta, Miklós; Krbec, Jaroslav; Stöckel, Jan; Weinzettl, Vladimír; Bencze, A.; Zoletnik, S.; Anda, G.
2015 - English
Atomic beam probe is a new diagnostic method for detection of ions coming from the ionized part of diagnostic neutral beams in tokamaks. The method allows to measure plasma density fluctuations and fast variations in the poloidal magnetic field. Therefore, one can follow fast changes in the edge plasma current. Test detector has been installed on COMPASS as an extension of lithium beam diagnostic and the article presents the first measurements done with the diagnostic
Keywords:
plasma; tokamak; diagnostic
Available at various institutes of the ASCR
Measurements with Atomic Beam Probe Diagnostic on the COMPASS Tokamak
Atomic beam probe is a new diagnostic method for detection of ions coming from the ionized part of diagnostic neutral beams in tokamaks. The method allows to measure plasma density fluctuations and ...
První experimenty s přípravou suspenzního nástřiku Al2O3 pomocí hybridního plazmového hořáku
Tesař, Tomáš; Mušálek, Radek; Medřický, Jan; Kotlan, Jiří; Pala, Zdeněk
2015 - Czech
Hybridní vodou stabilizovaný hořák WSP-H představuje zajímavou alternativu k běžným hořákům pro žárové stříkání, neboť poskytuje jedinečnou kombinaci rychlosti plazmatu a entalpie dostupné pro zpracování materiálu. V této práci je studován vliv depozičních parametrů na charakteristiky nástřiku. Jako modelový materiál byl použit nanometrický Al2O3 dispergovaný v etanolu. Nástřik byl zkoumán pomocí skenovací elektronové mikroskopie a rentgenové difrakce. Výsledky prokázaly závislost charakteru mikrostruktury a fázového složení na podávací vzdálenosti a podávaném množství suspenze. Výsledky jsou zajímavé pro další optimalizaci depozičního procesu Hybrid water stabilized plasmatron WSP-H represents an interesting alternative to common torches for thermal spraying, because it provides a unique combination of plasma velocity and enthalpy available for material processing. In this paper, influence of deposition parameters on coating characteristics was studied. Nanometric Al2O3 powder dispersed in ethanol was used as a model material. The coating was examined by scanning electron microscopy and X-ray diffraction and the results showed clear dependence of microstructure and phase composition on spraying distance and feed rate of the suspension. Results are promising for further optimization of the deposition process.
Keywords:
suspension plasma spraying; alumina; microstructure
Available at various institutes of the ASCR
První experimenty s přípravou suspenzního nástřiku Al2O3 pomocí hybridního plazmového hořáku
Hybridní vodou stabilizovaný hořák WSP-H představuje zajímavou alternativu k běžným hořákům pro žárové stříkání, neboť poskytuje jedinečnou kombinaci rychlosti plazmatu a entalpie dostupné pro ...
Enthalpy Probe Diagnostics of Steam/Argon Plasma Jet
Hlína, Michal; Hrabovský, Milan
2015 - English
DC plasma torch with argon/water stabilization features extreme properties of the exiting plasma jet. The plasma mass flow rate is very low while the temperature reaches very high values. Plasma properties were measured by enthalpy probe connected to a mass spectrometer. The measurements of enthalpy, temperature, density and dynamic pressure were carried out for three different arc currents and at atmospheric pressure. The dependences of plasma characteristics on arc current were shown.
Keywords:
enthalpy probe; thermal plasma; plasma diagnostics
Available at various institutes of the ASCR
Enthalpy Probe Diagnostics of Steam/Argon Plasma Jet
DC plasma torch with argon/water stabilization features extreme properties of the exiting plasma jet. The plasma mass flow rate is very low while the temperature reaches very high values. Plasma ...
Boronized stainless steel with zirconia coatings
Brožek, Vlastimil; Kolísko, J.; Kubatík, Tomáš František; Mastný, L.; Pokorný, P.; Tej, P.
2015 - English
Conditions of boronizing are described using a reactive diffusion method of boron from boron carbide and lanthanum hexaboride so that the formation of Fe2B is preferred to FeB which is more brittle and whose structure does not satisfy the conditions for perfect adhesion of modified zirconia ceramics. Perfectly rigid adhesive connection of needle-like embedded interlayers Fe2B in steel AISI 303 prepared by reactive diffusion of a boronizing medium without activators at 1000 ° C and exposure of 2-4 hours has the value of 20 - 24 MPa at the Pinn-off test.Ceramic coatings from Al2O3-ZrO2 ceramics formed on those interlayers have the value of bond strength up to 14 - 20 MPa.Thermal cycling between 100°C - 600 °C confirmed good adhesion of coatings with the underlying steel.During thermal cycling at elevated temperatures (600-1000 °C) there occurs a statistically significant number of faults in cohesion and mechanical destruction of the coatings. One of the reasons are secondary changes
Keywords:
Boronised steel; plasma spraying; ceramic coatings; bond strength; zirkonia coatings
Available at various institutes of the ASCR
Boronized stainless steel with zirconia coatings
Conditions of boronizing are described using a reactive diffusion method of boron from boron carbide and lanthanum hexaboride so that the formation of Fe2B is preferred to FeB which is more brittle ...
Radial propagation of L-mode structures in COMPASS tokamak
Kovařík, Karel; Ďuran, Ivan; Stöckel, Jan; Seidl, Jakub; Havlíček, Josef; Háček, Pavel; Spolaore, M.; Vianello, N.
2015 - English
Various structures appear in the tokamak scrape-off layer (SOL) plasma with effects on plasma behavior. The filamentary probe recently introduced in the COMPASS tokamak allows measurement of electrostatic and magnetic properties of the filaments and their changes in dependence on distance from the last closed flux surface. This work presents evolution of the measured electromagnetic properties and their radial profiles as a part of the complex study of the processes in the SOL.
Keywords:
plasma; tokamak
Available at various institutes of the ASCR
Radial propagation of L-mode structures in COMPASS tokamak
Various structures appear in the tokamak scrape-off layer (SOL) plasma with effects on plasma behavior. The filamentary probe recently introduced in the COMPASS tokamak allows measurement of ...
Microstructure and Properties of Spark Plasma Sintered Al-Zn-Mg-Cu Alloy.
Zyka, J.; Málek, J.; Pala, Zdeněk; Andršová, I.; Veselý, J.
2015 - English
High entropy alloys are a new material class with promising structural and mechanical properties in wide range of applications. In principle they consist of five or more elements in equimolar concentrations resulting basically in single phase microstructure. TaNbHfZrTi alloy was developed by Senkov for high temperature applications.\nSince all of these elements are biocompatible the TaNbHfZrTi alloy can be investigated as a prospective bio implant material. The alloy was prepared by vacuum arc melting, no annealing treatment was applied. Tensile test and hardness test at room temperature were performed with very good results: yield strength 1155 MPa, rupture strength 1212 MPa, Vickers hardness 359 HV30. Microstructure and fracture morphology was also investigated.
Keywords:
High Entropy Alloys; Microstructure; Mechanical Properties; Tensile Test
Available at various institutes of the ASCR
Microstructure and Properties of Spark Plasma Sintered Al-Zn-Mg-Cu Alloy.
High entropy alloys are a new material class with promising structural and mechanical properties in wide range of applications. In principle they consist of five or more elements in equimolar ...
Preliminary Measurements of Neutrons From The D-D Reaction in The Compass Tokamak
Dankowski, J.; Janky, Filip; Kurowski, A.; Stöckel, Jan; Twarog, D.
2014 - English
Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during experiment. He-3 detectors and bubble detectors as a support. The measurements are an introduction for neutron diagnostic on tokamak COMPASS and monitoring neutrons during discharges with Neutral Beam Injection (NBI). The He-3 counters and bubble detectors were located in two positions near tokamak vacuum chamber at a distance less than 40 cm to the centre of plasma. The neutrons flux was observed in ohmic discharges. However, analysis of our results does not indicate any clear source of neutrons production during ohmic discharges.
Keywords:
fusion; tokamak; neutrons; plasma diagnostics; COMPASS; bubble detectors
Available at various institutes of the ASCR
Preliminary Measurements of Neutrons From The D-D Reaction in The Compass Tokamak
Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during ...
Influence of isothermal exposure on microstructural changes resulting in delamination of eutectic Al2O3+ZrO2+SiO2 thermal barrier coatings
Jech, D.; Čelko, L.; Chráska, Tomáš; Slámečka, K.; Klakurková, L.; Dubský, Jiří; Švejcar, J.
2014 - English
Eutectic ceramic Al2O3-ZrO2-SiO2 also termed Eucor (as a top coat) and CoNiCrAlY (as a bond coat) coatings were sprayed onto the surface of recently developed fine-grained cast polycrystalline nickel-based superalloy Inconel 713 LC by means of water stabilized plasma (WSP) and atmospheric plasma spraying (APS) techniques, respectively.Specimens were subjected to isothermal oxidation at 1050 °C for 10, 50, 100, 200 and 500 hours in ambient atmosphere,prior to which a half of the as-sprayed specimens was annealed at the temperature of 950 °C for 10 hours.Influence of short-time and long-time isothermal exposure on interactions at the bond-coat/top-coat interface was studied.The uniform and continuous oxide layer,also termed the thermally grown oxide (TGO),was formed and grew at the bond-coat/top-coat interface in all samples, both with and without the heat pre-treatment. Relationship between the dwell time, heat treatment and TGO growth kinetics was quantified.Microstructural changes
Keywords:
Electron microscopy-scanning; Heat treatment; Image analysis; Thermal barrier coatings; Thermal plasma spraying
Available at various institutes of the ASCR
Influence of isothermal exposure on microstructural changes resulting in delamination of eutectic Al2O3+ZrO2+SiO2 thermal barrier coatings
Eutectic ceramic Al2O3-ZrO2-SiO2 also termed Eucor (as a top coat) and CoNiCrAlY (as a bond coat) coatings were sprayed onto the surface of recently developed fine-grained cast polycrystalline ...
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