40 research outputs found

    Erosion, permeation and outgassing performances of tin coating under/after hydrogen plasma iffadiation

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    An erosion behavior of TiN-coated stainless-steel (SS) surfaces was investigated during biased-limiter experiments within the Uragan-3M torsatron and during simulation experiments, which were performed with plasma-accelerator and glow-discharge (GD) plasmas. For a TiN-coated SS head-plate of a limiter the arc ignition probability was found to be lower than 10-4 per plasma pulse. Possible physical mechanisms of this effect had been discussed. Within special vacuum stands, using thermal-desorption and mass-spectrometry methods, there were performed measurements of an outgassing rate and hydrogen permeability of TiNcoatings. The negligible outgassing from TiN-coated SS samples, during their heating up to 473 K, was observed after a cleaning procedure with a molecular hydrogen inflow under pressure of about 10-4 Torr, on contrary to the considerable increase of (q) rate for the irradiated samples. Measured values of the TiN-film hydrogen permeability were several times lower, and activation energy of the hydrogen permeation was considerably lower than that for the SS films (15 kJ/mole instead of 19.9 kJ/mole). The use of TiN-coated SS and diffusion membranes, for the reduction of the erosion, recycling, and hydrogen isotope inventory control, as well as for improvement of vacuum conditions, has been considered

    An apparatus for sequential pulsed plasma beam treatment in combination with Arc PVD deposition

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    A hybrid type of apparatus is described which enables one to form a thin multi-layer film on the surface of any kind of solid substrate. In one process, the surface is treated with a high intensity pulse plasma beam which introduces the chosen kind of atoms into the near-surface layer of the substrate. In the second process, following the first without breaking the vacuum, the coating is formed by arc PVD (physical vapour deposition) process. Two examples of coatings formed on metallic and ceramic substrates are presented

    Badania powierzchniowej trwałości zmęczeniowej skojarzeń z nanowarstwami

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    The article presents results obtained in studies of surface fatigue life conducted using a specially developed unique method in a model system with a cone and three balls. The studies involved pairs in which the cones were made of 100Cr6 and SW7M steel (hardened) as well as 17HMN steel, which were subjected to low-pressure carburizing with pre-nitriding (PreNitLPC®) technology. The results obtained for the pairs were used as a point of reference for pairs in which the test elements were coated with a-C:H:W (WC/C) and additionally, in the case of 17HNM steel, with Si-DLC (DLC SiliComp). The temperature of the coating process did not exceed 200°C in all cases, and the coating thickness was in the range of 1.5-20 µm. The studies were conducted in the presence of pure synthetic oil PAO8. Based on the studies, it was concluded that thin PVD coatings applied to heavily loaded steel elements of rolling friction joints variously affected the surface fatigue life of the steel coated with them. The observations cannot be unambiguously accounted for by any technological rules, and there is no available physical explanation for their underlying causes.W artykule zaprezentowano wyniki badań powierzchniowej trwałości zmęczeniowej własną, unikatową metodą, w modelowym układzie stożek trzy kulki. Przeprowadzono badania skojarzeń, w których stożki wykonane były ze stali 100Cr6 i SW7M hartowanej oraz stali 17HMN, które poddano technologii nawęglania niskociśnieniowego wspomaganego azotowaniem PreNitLPC".Wyniki tych skojarzeń były bazą odniesienia dla skojarzeń, w których elementy testowe pokryte były powłoką a-C:H:W (WC/C) i dodatkowo w przypadku stali 17HNM powłoką Si-DLC (DLC SiliComp). Temperatura procesu nanoszenia powłok we wszystkich przypadkach nie przekraczała 200°C, natomiast ich grubość zawarta była w przedziale 1,5+2,0 µm. Badania przeprowadzono w obecności czystego oleju syntetycznego PAO8. Na podstawie przeprowadzonych badań stwierdzono, że cienkie powłoki PVD nanoszone na wysokoobciążone stalowe elementy tocznych węzłów tarcia w zróżnicowany sposób wpływają na powierzchniową trwałość zmęczeniową pokrytej nimi stali

    Changes of stainless steels surface morphology as a result of interaction with intense pulsed plasma beams containing ions of rare earth elements

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    Among different methods used in surface engineering such as CVD, PVD, ion implantation etc., the techniques using high intensity ion or plasma beams are relatively new ones. The results reported thus far show that the treatment of steel surface with high intensity plasma pulses can lead to changes of its morphology and mechanical properties. Stainless steels have very good corrosion resistance, but they have low hardness and poor tribological properties. The intense pulsed plasma beams were used for modification of alloyed steels especially austenitic (1.4301 and 1.4401) and ferritic (1.4016) stainless steels with various content of alloying elements. Samples were irradiated with 2, 5 or 10 short (μs scale) intense (density of energy was about 5 J/cm2) pulses. Heating and cooling processes were of non-equilibrium type. In all samples the near surface layer of the thickness in μm range was melted and simultaneously doped with cerium and lanthanum. The aim of this work was to investigate the changes of stainless steel surface morphology after melting, rare earth elements (REE) addition and rapid solidification after interaction with intense pulsed plasma beams. The surface morphology was analyzed using a scanning electron microscopy (SEM) technique. Changes of surface roughness were determined by profilometric measurements. The efficiency of REE addition process was also determined

    The influence of hybrid coatings on the fatigue life steel

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    W artykule zaprezentowano wyniki badań powierzchniowej trwałości zmęczeniowej próbek wykonanych ze stali 17HMN, które poddano technologii nawęglania niskociśnieniowego wspomaganego azotowaniem PreNitLPC® oraz próbek nawęglonych z naniesionymi technologią PVD powłokami niskotarciowymi typu: a-C:H:W (WC/C) a-C:H (DLC Comp) oraz Si-DLC (DLC SiliComp). Temperatura procesu nanoszenia powłok we wszystkich przypadkach nie przekraczała 200°C. Na podstawie przeprowadzonych badań stwierdzono, że cienkie powłoki PVD, nanoszone na wysokoobciążone stalowe elementy węzłów tarcia, w zróżnicowany sposób wpływają na powierzchniową trwałość zmęczeniową pokrytej nimi stali. Aby wyjaśnić przyczyny tego zróżnicowania, konieczne są dogłębne badania analityczne.The paper presents the results of research on the surface fatigue life (i.e. the resistance to pitting) of samples made of 17HMN steel, low-pressure carburized and PreNitLPC® nitriding assisted, as well as carburized samples with low-friction PVD coatings deposited onto the surface – a-C:H:W (trademark: WC/C), a-C:H (DLC Comp), and Si-DLC (DLC SiliComp) coatings were deposited. The coating process temperature in all the cases did not exceed 200°C. The investigated tribosystems were lubricated with a synthetic oil without additives. On the basis of the research results, it can be stated that thin PVD coatings, deposited onto heavy-loaded steel tribosystems, significantly and in a differentiated way affect the surface fatigue life. It seems necessary, apart from the fatigue wear investigation, to conduct profound analytical examinations aimed at explaining such a strongly different behaviour of elements working in a lubricated non-conformal contact

    The Possibility Of Use Of Laser-Modified Ti6Al4V Alloy In Friction Pairs In Endoprostheses

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    The purpose of this paper is to show results of laser treatment at cryogenic conditions of the Ti6Al4V alloy used for orthopedic applications. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. The paper presents the abrasive wear of the base and laser remelted material in association with ceramics Al2O3. Despite the surface cracking after laser treatment the tribological properties in simulated body fluid have been substantially improved

    Możliwość zastosowania modyfikowanego laserowo stopu Ti6Al4V na pary cierne endoprotez

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    The purpose of this paper is to show results of laser treatment at cryogenic conditions of the Ti6Al4V alloy used for orthopedic applications. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. The paper presents the abrasive wear of the base and laser remelted material in association with ceramics Al2O3. Despite the surface cracking after laser treatment the tribological properties in simulated body fluid have been substantially improved.Celem artykułu jest pokazanie rezultatów obróbki laserowej w warunkach kriogenicznych stopu Ti6Al4V używanego w aplikacjach ortopedycznych. Tego rodzaju proces modyfikacji powinien przynieść korzystne zmiany w mikrostrukturze i naprężeniach własnych warstwy wierzchniej. Artykuł prezentuje badania odporności na zużycie ścierne materiału podstawowego i nadtopionego laserowo w skojarzeniu z ceramiką Al2O3. Pomimo pęknięć na powierzchni materiału po obróbce laserowej własności tribologiczne badane w roztworze symulującym płyn ustrojowy zostały znacznie ulepszone

    Wettability of carbon and silicon carbide ceramics induced by their surface alloying with Zr and Cu elements using high intensity pulsed plasma beams

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    Joining of metals with ceramics is very difficult, because properties of these materials are very different. One of the methods of improving mechanical strength of the obtained joints is the introduction of an additional interlayer to the joining area. This paper presents the Zr and Cu-rich layers in C and SiC substrates obtained using the high intensity pulsed plasma beams method. The results of Zr plasma modifications were beneficial and similar to the results obtained in previous works with Ti. The measured contact angles were below 90 centigrade. The results with Cu plasma were unfavourable with contact angles close to 180 centigrade. Apart from the sessile-drop test and to extend the range of analysis, the investigated samples were examined by stereoscopic optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), grazing angle X-ray diffraction (GXRD), and Rutherford back scattering (RBS) measurements

    Ion Implantation and Transient Melting: A New Approach to Formation of Superconducting MgB2\text{}_{2} Phases

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    An attempt to synthesize superconducting MgB2\text{}_{2} inter-metallic compound from the liquid state is presented. The process consists of two steps. In the first one, boron ions are implanted into a magnesium substrate. In the second one, the near-surface region of such system is melted by short, intense hydrogen plasma pulses without necessity of annealing in Mg vapor. A magnetically modulated microwave absorption method was used to detect superconducting regions in the obtained MgB2\text{}_{2} layer. Percolation between nano-regions (islands) of MgB2\text{}_{2} has not been observed. However, a superconducting state of the insulated islands has been experimentally proven with transition temperatures TC\text{}_{C} as high as 31 K

    Urządzenie i metodyka badań tarciowo-zużyciowych warstewki antypoślizgowej na podeszwach obuwia

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    Injuries due to slips in swimming pools or toilets in hospitals are significant social problems. It primarily concerns children making use of swimming pools or hospitalised old people, and physically disabled. Thus, within the scope of a R&D project, coordinated by the company C.T. Service from Lesznowola, a formula and way of deposition for an anti-slip coating dedicated to the soles of shoes were developed in order to increase friction on wet surfaces. A special machine – T-31 Simulator – for tribological testing of the friction and wear of the soles of shoes was developed. A method for precise determination of the coefficient of friction between a sole of a shoe (with the coating or without, on dry or wet surface) and a floor material, and a method for determination of the life (resistance to abrasion) of the anti-slip coating under conditions simulating walking were developed. To verify the developed test methods, the anti-slip coating was deposited on three types of sole materials, i.e. Thunit, polyurethane, and thermoplastic rubber, sliding against four types of the floor material, i.e. floor tile “Gres,” laminated flooring, sandstone, and granite. The paper presents the developed test device and test methods for friction and wear testing of the anti-slip coating deposited on the soles of shoes. The selected research results are also presented. On their base, a very good repeatability and good resolution of the developed test methods were stated.Dużym problemem społecznym są poślizgnięcia i towarzyszące im urazy, np. na basenach czy w toaletach szpitalnych. Narażone są na nie w szczególności dzieci, korzystające z basenów czy leczone szpitalnie osoby w podeszłym wieku, z ograniczoną sprawnością ruchową. Wychodząc temu naprzeciw, w ramach projektu celowego POIG koordynowanego przez firmę C.T. Service z Lesznowoli, opracowano recepturę i sposób osadzania warstewki antypoślizgowej przeznaczonej do nanoszenia na podeszwę obuwia w celu zwiększenia tarcia na mokrej nawierzchni. Zaprojektowano i wykonano specjalne urządzenie do badań tribologicznych – Symulator T-31 do badania tarcia i zużycia materiałów na podeszwy obuwia. Opracowano metodykę precyzyjnego wyznaczania współczynnika tarcia podeszwy obuwia (z warstewką lub bez, na mokrej lub suchej nawierzchni) przy tarciu o określony rodzaj powierzchni podłogi oraz metodykę wyznaczania trwałości (odporności na ścieranie) warstewki antypoślizgowej w warunkach symulujących chód człowieka. Weryfikacja opracowanej metodyki badawczej odbyła się w badaniach warstewki nałożonej na trzy rodzaje podeszwy obuwia: tuniskór, poliuretan i kauczuk termoplastyczny, ślizgającej się o cztery rodzaje nawierzchni: gres, panel podłogowy laminowany, piaskowiec i granit. W artykule przedstawiono urządzenie i metodykę badań tarciowo-zużyciowych warstewki antypoślizgowej na podeszwach obuwia. Przedstawiono też wybrane wyniki badań weryfikacyjnych. Na ich podstawie stwierdzono bardzo dobrą powtarzalność i dobrą rozdzielczość opracowanych metod badań
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