WorldWideScience

Sample records for deposition processes coating

  1. Antireflection coatings on plastics deposited by plasma polymerization process

    Indian Academy of Sciences (India)

    K M K Srivatsa; M Bera; A Basu; T K Bhattacharya

    2008-08-01

    Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage process—exposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.

  2. Plasma Processes : Microwave plasma deposition of diamond like carbon coatings

    Indian Academy of Sciences (India)

    D S Patil; K Ramachandran; N Venkatramani; M Pandey; R D'Cunha

    2000-11-01

    The promising applications of the microwave plasmas have been appearing in the fields of chemical processes and semiconductor manufacturing. Applications include surface deposition of all types including diamond/diamond like carbon (DLC) coatings, etching of semiconductors, promotion of organic reactions, etching of polymers to improve bonding of the other materials etc. With a 2.45 GHz, 700 W, microwave induced plasma chemical vapor deposition (CVD) system set up in our laboratory we have deposited diamond like carbon coatings. The microwave plasma generation was effected using a wave guide single mode applicator. We have deposited DLC coatings on the substrates like stainless steel, Cu–Be, Cu and Si. The deposited coatings have been characterized by FTIR, Raman spectroscopy and ellipsometric techniques. The results show that we have achieved depositing ∼ 95% sp3 bonded carbon in the films. The films are uniform with golden yellow color. The films are found to be excellent insulators. The ellipsometric measurements of optical constant on silicon substrates indicate that the films are transparent above 900 nm.

  3. Deposition of wear-resistant steel surfaces by the plasma rotating electrode coating process

    Science.gov (United States)

    Kim, Michael Robert

    A high-deposition rate thermal spray method was investigated for the purpose of coating aluminum cylinder bores with a wear resistant surface. This method, the plasma rotating electrode coating system (PROTEC) utilized transferred-arc melting of a rapidly rotating consumable electrode to create a droplet stream via centrifugal atomization. A cylindrical substrate was placed around the rotating rod, in the flight path of the droplets, to deposit a coating onto the internal surface of the cylinder. Selected coatings of 1045 steel deposited by the PROTEC coating method exhibited lower wear loss in lubricated sliding than wire-arc sprayed carbon steel coatings and gray cast iron. Splat cohesion was shown to be a significant factor in the wear resistance of PROTEC coatings. The relationship between deposition enthalpy and cooling rate of the coating was found to have the greatest effect on coating microstructure, and the coating cohesion. The most rapidly solidified coatings showed inferior splat cohesion in comparison to coatings that cooled more slowly. The increase in splat cohesion with decreased cooling rate was accompanied by the formation of a directionally oriented coating microstructure, likely formed during cellular solidification of the coating. A model describing the thermal state of the deposition process was used to predict the deposition conditions that would result in a cellular structure, and the level of splat cohesion required to produce a wear resistant coating.

  4. Electrospark deposition coatings

    Science.gov (United States)

    Sheely, W. F.

    1986-11-01

    Hard surfacing for wear resistant and low-friction coatings has been improved by means of advances in the computer controls in electronic circuitry of the electrospark deposition (ESD) process. coatings of nearly any electrically conductive metal alloy or cermet can be deposited on conductive materials. Thickness is usually two mils or less, but can be as high as 10 mils. ESD coatings can quadrupole cutting tool life.

  5. Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

    Directory of Open Access Journals (Sweden)

    Fang Luo

    2015-03-01

    Full Text Available Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

  6. Research on chemical vapor deposition processes for advanced ceramic coatings

    Science.gov (United States)

    Rosner, Daniel E.

    1993-01-01

    Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

  7. The erosion performance of cold spray deposited metal matrix composite coatings with subsequent friction stir processing

    Science.gov (United States)

    Peat, Tom; Galloway, Alexander; Toumpis, Athanasios; McNutt, Philip; Iqbal, Naveed

    2017-02-01

    This study forms an initial investigation into the development of SprayStir, an innovative processing technique for generating erosion resistant surface layers on a chosen substrate material. Tungsten carbide - cobalt chromium, chromium carbide - nickel chromium and aluminium oxide coatings were successfully cold spray deposited on AA5083 grade aluminium. In order to improve the deposition efficiency of the cold spray process, coatings were co-deposited with powdered AA5083 using a twin powder feed system that resulted in thick (>300 μm) composite coatings. The deposited coatings were subsequently friction stir processed to embed the particles in the substrate in order to generate a metal matrix composite (MMC) surface layer. The primary aim of this investigation was to examine the erosion performance of the SprayStirred surfaces and demonstrate the benefits of this novel process as a surface engineering technique. Volumetric analysis of the SprayStirred surfaces highlighted a drop of approx. 40% in the level of material loss when compared with the cold spray deposited coating prior to friction stir processing. Micro-hardness testing revealed that in the case of WC-CoCr reinforced coating, the hardness of the SprayStirred material exhibits an increase of approx. 540% over the unaltered substrate and 120% over the as-deposited composite coating. Microstructural examination demonstrated that the increase in the hardness of the MMC aligns with the improved dispersion of reinforcing particles throughout the aluminium matrix.

  8. SiNx coatings deposited by reactive high power impulse magnetron sputtering: Process parameters influencing the residual coating stress

    Science.gov (United States)

    Schmidt, S.; Hänninen, T.; Wissting, J.; Hultman, L.; Goebbels, N.; Santana, A.; Tobler, M.; Högberg, H.

    2017-05-01

    The residual coating stress and its control is of key importance for the performance and reliability of silicon nitride (SiNx) coatings for biomedical applications. This study explores the most important deposition process parameters to tailor the residual coating stress and hence improve the adhesion of SiNx coatings deposited by reactive high power impulse magnetron sputtering (rHiPIMS). Reactive sputter deposition and plasma characterization were conducted in an industrial deposition chamber equipped with pure Si targets in N2/Ar ambient. Reactive HiPIMS processes using N2-to-Ar flow ratios of 0 and 0.28-0.3 were studied with time averaged positive ion mass spectrometry. The coatings were deposited to thicknesses of 2 μm on Si(001) and to 5 μm on polished CoCrMo disks. The residual stress of the X-ray amorphous coatings was determined from the curvature of the Si substrates as obtained by X-ray diffraction. The coatings were further characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, and nanoindentation in order to study their elemental composition, morphology, and hardness, respectively. The adhesion of the 5 μm thick coatings deposited on CoCrMo disks was assessed using the Rockwell C test. The deposition of SiNx coatings by rHiPIMS using N2-to-Ar flow ratios of 0.28 yield dense and hard SiNx coatings with Si/N ratios <1. The compressive residual stress of up to 2.1 GPa can be reduced to 0.2 GPa using a comparatively high deposition pressure of 600 mPa, substrate temperatures below 200 °C, low pulse energies of <2.5 Ws, and moderate negative bias voltages of up to 100 V. These process parameters resulted in excellent coating adhesion (ISO 0, HF1) and a low surface roughness of 14 nm for coatings deposited on CoCrMo.

  9. Preparation of Chromium Oxide Coatings on Aluminum Borate Whiskers by a Hydrothermal Deposition Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Aluminum borate whiskers (9Al2O32B2O3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium-coating deposits in a hydrothermal solution containing CrCl3, Na2C4H4O6, NaPH2O2, and H3BO3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH2O2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr2O3 films with a thickness of 0.060.07 μm.

  10. Nanostructured bioactive glass-ceramic coatings deposited by the liquid precursor plasma spraying process

    Science.gov (United States)

    Xiao, Yanfeng; Song, Lei; Liu, Xiaoguang; Huang, Yi; Huang, Tao; Wu, Yao; Chen, Jiyong; Wu, Fang

    2011-01-01

    Bioactive glass-ceramic coatings have great potential in dental and orthopedic medical implant applications, due to its excellent bioactivity, biocompatibility and osteoinductivity. However, most of the coating preparation techniques either produce only thin thickness coatings or require tedious preparation steps. In this study, a new attempt was made to deposit bioactive glass-ceramic coatings on titanium substrates by the liquid precursor plasma spraying (LPPS) process. Tetraethyl orthosilicate, triethyl phosphate, calcium nitrate and sodium nitrate solutions were mixed together to form a suspension after hydrolysis, and the liquid suspension was used as the feedstock for plasma spraying of P 2O 5-Na 2O-CaO-SiO 2 bioactive glass-ceramic coatings. The in vitro bioactivities of the as-deposited coatings were evaluated by soaking the samples in simulated body fluid (SBF) for 4 h, 1, 2, 4, 7, 14, and 21 days, respectively. The as-deposited coating and its microstructure evolution behavior under SBF soaking were systematically analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma (ICP), and Fourier transform infrared (FTIR) spectroscopy. The results showed that P 2O 5-Na 2O-CaO-SiO 2 bioactive glass-ceramic coatings with nanostructure had been successfully synthesized by the LPPS technique and the synthesized coatings showed quick formation of a nanostructured HCA layer after being soaked in SBF. Overall, our results indicate that the LPPS process is an effective and simple method to synthesize nanostructured bioactive glass-ceramic coatings with good in vitro bioactivity.

  11. Parametric study of an HVOF process for the deposition of nanostructured WC-Co coatings

    Science.gov (United States)

    Bartuli, Cecilia; Valente, Teodoro; Cipri, Fabio; Bemporad, Edoardo; Tului, Mario

    2005-06-01

    Nanocrystalline WC-Co coatings were deposited by high velocity oxyfuel from commercial nanostructured composite powders. Processing parameters were optimized for maximal retention of the nanocrystalline size and for minimal decarburation of the ceramic reinforcement. Thermochemical and gas-dynamical properties of gas and particle flows within the combustion flame were identified in various operating conditions by computational fluid-dynamics (CFD) simulation. Significant improvements of the mechanical properties of the coatings were obtained: a decrease of the friction coefficient was measured for the nanostructured coatings, together with an increase of microhardness and fracture toughness.

  12. Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process

    Energy Technology Data Exchange (ETDEWEB)

    Tlotleng, Monnamme, E-mail: MTlotleng@csir.co.za [Laser Materials Processing Group, National Laser Center CSIR, Pretoria 0001 (South Africa); Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park, Kingsway Campus, Johannesburg 2006 (South Africa); Akinlabi, Esther [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park, Kingsway Campus, Johannesburg 2006 (South Africa); Shukla, Mukul [Department of Mechanical Engineering Technology, University of Johannesburg, Doornfontein Campus, Johannesburg 2006 (South Africa); Department of Mechanical Engineering, MNNIT, Allahabad, UP 211004 (India); Pityana, Sisa [Laser Materials Processing Group, National Laser Center CSIR, Pretoria 0001 (South Africa); Department of Chemical and Metallurgical Engineering, Tshwane University of Technology, Pretoria 0001 (South Africa)

    2014-10-01

    Hydroxyapatite (HAP) coatings on bioinert metals such as Ti–6Al–4V are necessary for biomedical applications. Together, HAP and Ti–6Al–4V are biocompatible and bioactive. The challenges of depositing HAP on Ti–6Al–4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti–6Al–4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750 W led to no dilution. The microhardness results inferred a strong intermetallic–ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications. - Highlights: • Characteristics of HAP coatings produced on Ti-6Al-4V achieved with direct laser melting are reported. • Optimal process parameters necessary to achieve biocompatible coating are reported. • The SEM micrograph of the soaked HAP coating revealed partially melted crystals of HAP. • The HAP coating was retained at the surface of

  13. Fabrication of Nanosized Lanthanum Zirconate Powder and Deposition of Thermal Barrier Coating by Plasma Spray Process

    Science.gov (United States)

    Mishra, S. K.; Jagdeesh, N.; Pathak, L. C.

    2016-07-01

    The present manuscript discusses our findings on fabrication of nanosized lanthanum zirconate powder for thermal barrier coating application and its coating by plasma spray on nickel-based superalloy substrate. Single-phase La2Zr2O7 coating of thickness of the order of 45 µm on the Ni-Cr-Al bond coat coated Ni-based superalloy substrate was deposited by plasma spray process. The layers at the interface did not show spallation and inter diffusion was very less. The microstructure, interface, porosity, and mechanical properties of different layers are investigated. The lanthanum zirconate hardness and modulus were 10.5 and 277 GPa, respectively. The load depth curve for lanthanum zirconate showed good elastic recovery around 74%.

  14. The Influence of Process Parameters on Properties of Conversion Coatings Deposited on Titanium Alloy

    Directory of Open Access Journals (Sweden)

    Karaś M.

    2016-03-01

    Full Text Available The effect of process parameters of conversion coatings on the corrosion resistance was investigated. To produce anodic coatings, the solutions of H2SO4 of 0.5 and 1 M concentrations and current densities of 0.5 and 1 A/dm2 were applied. The coatings were deposited by galvanostatic technique on titanium Grade 1. The result of the study was comparison of the corrosion resistance of coatings produced under varying parameters such as: the anodic current density, the electrolyte concentration, and the speed of reaching the preset voltage. Corrosion tests performed by potentiodynamic polarization test have shown that even nanometric anodic films of amorphous structure improve the corrosion resistance of titanium alloy. The lowest corrosion current and the corrosion potential of the most cathodic nature were observed in the sample with anodic coating produced at J = 1 A/dm2 in a 0.5 M H2SO4 electrolyte concentration.

  15. Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process.

    Science.gov (United States)

    Tlotleng, Monnamme; Akinlabi, Esther; Shukla, Mukul; Pityana, Sisa

    2014-10-01

    Hydroxyapatite (HAP) coatings on bioinert metals such as Ti-6Al-4V are necessary for biomedical applications. Together, HAP and Ti-6Al-4V are biocompatible and bioactive. The challenges of depositing HAP on Ti-6Al-4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti-6Al-4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750 W led to no dilution. The microhardness results inferred a strong intermetallic-ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications.

  16. Empirical-Statistical Study on the Relationship between Deposition Parameters, Process Variables, Deposition Rate and Mechanical Properties of a-C:H:W Coatings

    Directory of Open Access Journals (Sweden)

    Harald Hetzner

    2014-12-01

    Full Text Available Tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W were deposited on high speed steel by reactive magnetron sputtering of a tungsten carbide target in an argon-ethine atmosphere. The deposition parameters, sputtering power, bias voltage, argon and ethine flow rate, were varied according to a central composite design comprising 25 different parameter combinations. For comparison, a tungsten carbide coating was deposited, as well. During coating deposition, the process variables, total pressure, sputtering voltage and bias current, were measured as process characteristics. The thickness of the deposited coatings was determined using the crater grinding method, and the deposition rate was calculated. Young’s modulus E and indentation hardness HIT were characterized by means of nanoindentation. With E = 80

  17. Studies on Nanostructure Aluminium Thin Film Coatings Deposited using DC magnetron Sputtering Process

    Science.gov (United States)

    Singh M, Muralidhar; G, Vijaya; MS, Krupashankara; Sridhara, B. K.; Shridhar, T. N.

    2016-09-01

    Nanostructured thin film metallic coatings has become an area of intense research particularly in applications related solar, sensor technologies and many other optical applications such as laser windows, mirrors and reflectors. Thin film metallic coatings were deposited using DC magnetron sputtering process. The deposition rate was varied to study its influence on optical behavior of Aluminum thin films at a different argon flow rate. Studies on the optical response of these nanostructure thin film coatings were characterized using UV-VIS-NIR spectrophotometer with integrating sphere in the wavelength range of (250-2500nm) and Surface morphology were carried out using atomic force microscope with roughness ranging from 2 to 20nm and thickness was measured using Dektak measuring instrument. The reflection behavior of aluminium coatings on polycarbonate substrates has been evaluated. UV-VIS-NIR Spectrophotometer analysis indicates higher reflectance of 96% for all the films in the wavelength range of 250 nm to 2500 nm. Nano indentation study revealed that there was a considerable change in hardness values of the films prepared at different conditions.

  18. Microstructural Effects and Properties of Non-line-of-Sight Coating Processing via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan J.; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2017-08-01

    Plasma spray-physical vapor deposition (PS-PVD) is a unique processing method that bridges the gap between conventional thermal spray and vapor phase methods, and enables highly tailorable coatings composed of a variety of materials in thin, dense layers or columnar microstructures with modification of the processing conditions. The strengths of this processing technique are material and microstructural flexibility, deposition speed, and potential for non-line-of-sight (NLOS) capability by vaporization of the feedstock material. The NLOS capability of PS-PVD is investigated here using yttria-stabilized zirconia and gadolinium zirconate, which are materials of interest for turbine engine applications. PS-PVD coatings were applied to static cylindrical substrates approximately 6-19 mm in diameter to study the coating morphology as a function of angle. In addition, coatings were deposited on flat substrates under various impingement configurations. Impingement angle had significant effects on the deposition mode, and microscopy of coatings indicated that there was a shift in the deposition mode at approximately 90° from incidence on the cylindrical samples, which may indicate the onset of more turbulent flow and PVD-like growth. Coatings deposited at non-perpendicular angles exhibited a higher density and nearly a 2× improvement in erosion performance when compared to coatings deposited with the torch normal to the surface.

  19. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  20. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  1. Development of coatings for ultrasonic additive manufacturing sonotrode using laser direct metal deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Niyanth [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dehoff, Ryan R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jordan, Brian H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Babu, Sudarsanam Suresh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    ORNL partnered with Fabrisonic, LLC to develop galling resistant hard facing coatings on sonotrodes used to fabricate 3D printed materials using ultrasonic additive manufacturing. The development and deployment of a coated sonotrode is expected to push the existing state of the art to facilitate the solidstate additive manufacturing of hard steels and titanium alloys. To this effect a structurally amorphous stainless steel material and cobalt chrome material were deposited on the sonotrode material. Both the deposits showed good adhesion to the substrate. The coatings made using the structurally amorphous steel materials showed cracking during the initial trials and cracking was eliminated by deposition on a preheated substrate. Both the coatings show hardness in excess of 600 HVN. Thus the phase 1 of this project has been used to identify suitable materials to use to coat the sonotrode. Despite the fact that successful deposits were obtained, the coatings need to be evaluated by performing detailed galling tests at various temperatures. In addition field tests are also necessary to test the stability of these coatings in a high cycle ultrasonic vibration mode. If awarded, phase 2 of the project would be used to optimize the composition of the deposit material to maximize galling resistance. The industrial partner would then use the coated sonotrode to fabricate builds made of austenitic stainless steel to test the viability of using a coated sonotrode.

  2. Chemical vapor deposition of mullite coatings

    Science.gov (United States)

    Sarin, Vinod; Mulpuri, Rao

    1998-01-01

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  3. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    Science.gov (United States)

    Razza, Stefano; Castro-Hermosa, Sergio; Di Carlo, Aldo; Brown, Thomas M.

    2016-09-01

    To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating), as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  4. Apatite formation on alkaline-treated dense TiO2 coatings deposited using the solution precursor plasma spray process.

    Science.gov (United States)

    Chen, Dianying; Jordan, Eric H; Gell, Maurice; Wei, Mei

    2008-05-01

    A dense titania (TiO2) coating was deposited from an ethanol-based solution containing titanium isopropoxide using the solution precursor plasma spray (SPPS) process. XRD and Raman spectrum analyses confirmed that the coating is exclusively composed of rutile TiO2. SEM micrographs show the as-sprayed coating is dense with a uniform thickness and there are no coarse splat boundaries. The as-sprayed coating was chemically treated in 5M NaOH solution at 80 degrees C for 48 h. The bioactivity of as-sprayed and alkaline-treated coatings was investigated by immersing the coatings in simulated body fluid (SBF) for 14-28 days, respectively. After 28 days immersion, there is a complete layer of carbonate-containing apatite formed on the alkaline-treated TiO2 coating surface, but none formed on the as-sprayed coating.

  5. Spray-Deposited Superconductor/Polymer Coatings

    Science.gov (United States)

    Wise, Stephanie A.; Tran, Sang Q.; Hooker, Matthew W.

    1993-01-01

    Coatings that exhibit the Meissner effect formed at relatively low temperature. High-temperature-superconductor/polymer coatings that exhibit Meissner effect deposited onto components in variety of shapes and materials. Simple, readily available equipment needed in coating process, mean coatings produced economically. Coatings used to keep magnetic fields away from electronic circuits in such cryogenic applications as magnetic resonance imaging and detection of infrared, and in magnetic suspensions to provide levitation and/or damping of vibrations.

  6. Structure and Surface Characterization of Nanostructured Tio2 Coatings Deposited Via HVOF Thermal Spray Processes

    Directory of Open Access Journals (Sweden)

    Maryamossadat Bozorgtabar

    2015-01-01

    Full Text Available Titanium dioxide coatings were deposited by high velocity oxy-fuel spraying (HVOF with the use of agglomerated P25/20 nano-powder and different spraying parameters (e.g. fuel/flow ratio to determine their influence on the microstructure, crystalline structure and surface feature of the coatings. The microstructure of as-sprayed TiO2 coatings was characterized by scanning electron microscope (SEM, transmission electron microscope (TEM and X-ray diffraction (XRD. Surface features were investigated by Fourier transform infrared (FT-IR and X-ray photoelectron spectroscopy (XPS. The results showed that the fuel and oxygen flow ratio have an important influence on the microstructure, anatase content, surface chemical state and surface feature of the TiO2 coatings

  7. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    Directory of Open Access Journals (Sweden)

    Stefano Razza

    2016-09-01

    Full Text Available To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating, as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  8. Corrosion Resistance of Ni-Based WC/Co Coatings Deposited by Spray and Fuse Process Varying the Oxygen Flow

    Science.gov (United States)

    Jiménez, H.; Olaya, J. J.; Alfonso, J. E.; Mtshali, C. B.; Pineda-Vargas, C. A.

    2017-08-01

    In this work, the effect of oxygen flow variation in the corrosion behavior of Ni-based WC/Co coatings deposited by spray and fuse process was investigated. The coatings were deposited on gray cast iron substrates using a Superjet Eutalloy thermal spraying gun. The morphology of the coatings was analyzed using scanning electron microscopy. The crystallographic phases were registered by x-ray diffraction (XRD), the diffraction patterns show the crystalline phases of the powder components with principal reflections for Ni and WC, the increase in flame temperature, due to the oxygen flow variation, generated amorphization in the nickel and an important crystallization of the planes (111) and (222) of WC as well as the decarburization of WC in W2C and W metallic. The corrosion behavior was investigated at room temperature in a 3.5% w/w aqueous solution of NaCl via potentiodynamic polarization. Electrochemical corrosion test showed that the coatings deposited under neutral flame conditions with an oxygen flow of 12.88 SCFH evidenced higher corrosion resistance. The chemical composition of the coatings and corrosion areas were analyzed by particle-induced x-ray emission, this technique permitting the corroboration of the decarburization process of WC determined by XRD and the formation of Cl structures.

  9. Clean diffusion coatings by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Warnes, B.M.; Punola, D.C. [Howmet Thermatech Coatings, Whitehall, MI (United States)

    1997-10-01

    An experimental program was undertaken to identify diffusion coating impurities introduced by standard aluminizing processes and to evaluate the impact of those impurities on oxidation resistance of the resultant Pt aluminide coating. IN-738 tabs and foils were platinum-electroplated, and then aluminized using three different processes: high-activity pack cementation, high-activity CVD and low-activity CVD. The results suggest that aluminizing processes which involve aluminum bearing alloys in the coating retort with H{sub 2} or H{sub 2}/HCl gas at high temperature can contaminate the diffusion coating during deposition. CVD low-activity aluminizing (coating gas generated at low temperature outside the coating chamber from 99.999% Al) did not introduce any coating impurities. In addition, the data indicates that harmful impurities from the IN-738 substrate (sulfur, boron and tungsten) and the electroplating process (phosphorus) were removed from the coating during deposition. The CVD low-activity Pt aluminide coating was the `cleanest` in the study, and it exhibited the best high-temperature oxidation resistance of the coatings considered. It can be concluded that trace elements in diffusion coatings from the superalloy substrate and/or the aluminizing process can adversely effect the oxidation resistance of those coatings, and that CVD low-activity aluminizing yields cleaner coatings than other commercially available aluminizing techniques. (orig.) 10 refs.

  10. Electrochemical characterization of YSZ thick films deposited by dip-coating process

    Science.gov (United States)

    Mauvy, F.; Lenormand, P.; Lalanne, C.; Ansart, F.; Bassat, J. M.; Grenier, J. C.; Groupement de Recherches Cnrs "Pacte", Gdr 2985

    Yttria stabilized zirconia (YSZ, 8% Y 2O 3) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK-EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films.

  11. Electrochemical characterization of YSZ thick films deposited by dip-coating process

    Energy Technology Data Exchange (ETDEWEB)

    Mauvy, F.; Lalanne, C.; Bassat, J.M.; Grenier, J.C. [Institut de Chimie de la Matiere Condensee de Bordeaux ICMCB - CNRS, Universite Bordeaux 1, 87, av. du Dr. A. Schweitzer, 33 608 Pessac-Cedex (France); Lenormand, P.; Ansart, F. [Centre Interuniversitaire de Recherche et d' Ingenierie et d' Ingenierie des Materiaux, CIRIMAT, Universite Paul Sabatier, Bat. 2R1, 118 route de Narbonne, 31062 Toulouse Cedex (France)

    2007-09-27

    Yttria stabilized zirconia (YSZ, 8% Y{sub 2}O{sub 3}) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK-EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films. (author)

  12. Highly Segmented Thermal Barrier Coatings Deposited by Suspension Plasma Spray: Effects of Spray Process on Microstructure

    Science.gov (United States)

    Chen, Xiaolong; Honda, Hiroshi; Kuroda, Seiji; Araki, Hiroshi; Murakami, Hideyuki; Watanabe, Makoto; Sakka, Yoshio

    2016-12-01

    Effects of the ceramic powder size used for suspension as well as several processing parameters in suspension plasma spraying of YSZ were investigated experimentally, aiming to fabricate highly segmented microstructures for thermal barrier coating (TBC) applications. Particle image velocimetry (PIV) was used to observe the atomization process and the velocity distribution of atomized droplets and ceramic particles travelling toward the substrates. The tested parameters included the secondary plasma gas (He versus H2), suspension injection flow rate, and substrate surface roughness. Results indicated that a plasma jet with a relatively higher content of He or H2 as the secondary plasma gas was critical to produce highly segmented YSZ TBCs with a crack density up to 12 cracks/mm. The optimized suspension flow rate played an important role to realize coatings with a reduced porosity level and improved adhesion. An increased powder size and higher operation power level were beneficial for the formation of highly segmented coatings onto substrates with a wider range of surface roughness.

  13. SiNx Coatings Deposited by Reactive High Power Impulse Magnetron Sputtering: Process Parameters Influencing the Nitrogen Content.

    Science.gov (United States)

    Schmidt, Susann; Hänninen, Tuomas; Goyenola, Cecilia; Wissting, Jonas; Jensen, Jens; Hultman, Lars; Goebbels, Nico; Tobler, Markus; Högberg, Hans

    2016-08-10

    Reactive high power impulse magnetron sputtering (rHiPIMS) was used to deposit silicon nitride (SiNx) coatings for biomedical applications. The SiNx growth and plasma characterization were conducted in an industrial coater, using Si targets and N2 as reactive gas. The effects of different N2-to-Ar flow ratios between 0 and 0.3, pulse frequencies, target power settings, and substrate temperatures on the discharge and the N content of SiNx coatings were investigated. Plasma ion mass spectrometry shows high amounts of ionized isotopes during the initial part of the pulse for discharges with low N2-to-Ar flow ratios of <0.16, while signals from ionized molecules rise with the N2-to-Ar flow ratio at the pulse end and during pulse-off times. Langmuir probe measurements show electron temperatures of 2-3 eV for nonreactive discharges and 5.0-6.6 eV for discharges in transition mode. The SiNx coatings were characterized with respect to their composition, chemical bond structure, density, and mechanical properties by X-ray photoelectron spectroscopy, X-ray reflectivity, X-ray diffraction, and nanoindentation, respectively. The SiNx deposition processes and coating properties are mainly influenced by the N2-to-Ar flow ratio and thus by the N content in the SiNx films and to a lower extent by the HiPIMS frequencies and power settings as well as substrate temperatures. Increasing N2-to-Ar flow ratios lead to decreasing growth rates, while the N content, coating densities, residual stresses, and the hardness increase. These experimental findings were corroborated by density functional theory calculations of precursor species present during rHiPIMS.

  14. Chemical vapor deposition coating for micromachines

    Energy Technology Data Exchange (ETDEWEB)

    MANI,SEETHAMBAL S.; FLEMING,JAMES G.; SNIEGOWSKI,JEFFRY J.; DE BOER,MAARTEN P.; IRWIN,LAWRENCE W.; WALRAVEN,JEREMY A.; TANNER,DANELLE M.; DUGGER,MICHAEL T.

    2000-04-21

    Two major problems associated with Si-based MEMS devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, the authors will present a process used to selectively coat MEMS devices with tungsten using a CVD (Chemical Vapor Deposition) process. The selective W deposition process results in a very conformal coating and can potentially solve both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through silicon reduction of WF{sub 6}, which results in a self-limiting reaction. The selective deposition of W only on polysilicon surfaces prevents electrical shorts. Further, the self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. Selective tungsten is deposited after the removal of the sacrificial oxides to minimize process integration problems. This tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. Results from tungsten deposition on MEMS structures with dimples will be presented. The effect of wet and vapor phase cleanings prior to the deposition will be discussed along with other process details. The W coating improved wear by orders of magnitude compared to uncoated parts. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable.

  15. An Alternative Low-Cost Process for Deposition of MCrAlY Bond Coats for Advanced Syngas/Hydrogen Turbine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying [Tennessee Technological Univ., Cookeville, TN (United States)

    2015-09-11

    The objective of this project was to develop and optimize MCrAlY bond coats for syngas/hydrogen turbine applications using a low-cost electrolytic codeposition process. Prealloyed CrAlY-based powders were codeposited into a metal matrix of Ni, Co or Ni-Co during the electroplating process, and a subsequent post-deposition heat treatment converted it to the MCrAlY coating. Our research efforts focused on: (1) investigation of the effects of electro-codeposition configuration and parameters on the CrAlY particle incorporation in the NiCo-CrAlY composite coatings; (2) development of the post-deposition heat treating procedure; (3) characterization of coating properties and evaluation of coating oxidation performance; (4) exploration of a sulfurfree electroplating solution; (5) cost analysis of the present electrolytic codeposition process. Different electro-codeposition configurations were investigated, and the rotating barrel system demonstrated the capability of depositing NiCo-CrAlY composite coatings uniformly on the entire specimen surface, with the CrAlY particle incorporation in the range 37-42 vol.%. Post-deposition heat treatment at 1000-1200 °C promoted interdiffusion between the CrAlY particles and the Ni-Co metal matrix, resulting in β/γ’/γ or β/γ’ phases in the heat-treated coatings. The results also indicate that the post-deposition heat treatment should be conducted at temperatures ≤1100 °C to minimize Cr evaporation and outward diffusion of Ti. The electro-codeposited NiCrAlY coatings in general showed lower hardness and surface roughness than thermal spray MCrAlY coatings. Coating oxidation performance was evaluated at 1000-1100 °C in dry and wet air environments. The initial electro-codeposited NiCoCrAlY coatings containing relatively high sulfur did not show good oxidation resistance. After modifications of the coating process, the cleaner NiCoCrAlY coating exhibited good oxidation performance at 1000 °C during the 2,000 1-h cyclic

  16. Nanocomposite Lanthanum Zirconate Thermal Barrier Coating Deposited by Suspension Plasma Spray Process

    Science.gov (United States)

    Wang, Chaohui; Wang, You; Wang, Liang; Hao, Guangzhao; Sun, Xiaoguang; Shan, Fan; Zou, Zhiwei

    2014-10-01

    This work seeks to develop an innovative nanocomposite thermal barrier coating (TBC) exhibiting low thermal conductivity and high durability compared with that of current TBCs. To achieve this objective, nanosized lanthanum zirconate particles were selected for the topcoat of the TBC system, and a new process—suspension plasma spray—was employed to produce desirable microstructural features: the nanocomposite lanthanum zirconate TBC contains ultrafine splats and high volume porosity, for lower thermal conductivity, and better durability. The parameters of plasma spray experiment included two main variables: (i) spray distance varying from 40 to 80 mm and (ii) the concentration of suspension 20, 25, and 30 wt.%, respectively. The microstructure of obtained coatings was characterized with scanning electron microscope and x-ray diffraction. The porosity of coatings is in the range of 6-10%, and the single phase in the as-sprayed coatings was pyrochlore lanthanum zirconate.

  17. High speed titanium coating by Supersonic Laser Deposition

    OpenAIRE

    LUPOI, ROCCO

    2011-01-01

    PUBLISHED The importance of metal coating technologies drives the continuous improvement of metal deposition techniques for application in a wide range of industrial sectors. This work presents the foundations of a new process technology f or the deposition of t itanium coatings on steel tube substrates using supersonic powder streams and impact site laser heating , known as Supersonic Laser Deposition (SLD). M et...

  18. Characteristic Features of the Formation of a Combined Magnetron-Laser Plasma in the Processes of Deposition of Film Coatings

    Science.gov (United States)

    Burmakov, A. P.; Kuleshov, V. N.; Prokopchik, K. Yu.

    2016-09-01

    A block diagram of a facility for combined magnetron-laser deposition of coatings and of the systems of controlling and managing this process is considered. The results of analysis of the influence of the gas medium and of laser radiation parameters on the emission-optical properties of laser plasma are considered. The influence of the laser plasma on the electric characteristics of a magnetron discharge is analyzed. The formation of the laser plasma-initiated pulse arc discharge has been established and the influence of the laser radiation parameters on the electric characteristics of this discharge has been determined. The emission optical spectra of the magnetron discharge plasma and of erosion laser plasma are compared separately and in combination.

  19. Accelerated electrospark deposition and the wear behavior of coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.Z.; Pan, G.S.; Zhou, Y.; Qu, J.X.; Shao, H.S. [China Univ. of Mining and Technology, Beijing (China). Beijing Graduate School

    1997-12-01

    Electrospark deposition (ESD) is a coating process that is featured by low heat input to the substrate. Low coating efficiency and other limitations influence its wider application. The present paper introduces newly designed ESD equipment, by which a higher coating rate can be reached. The relationship among coating thickness, surface roughness, and process parameters such as pulse energy, pulse frequency, and deposition time are presented. Electrospark deposition coating by the new equipment on AISI 1045 steel (with WC-8% Co as electrode) increases the wear resistance by 5 to 8 times. The micromechanism is investigated by scanning electron microscopy observation.

  20. Effects of various power process parameters on deposition efficiency of plasma-sprayed Al2O3-40% wt.TiO2 coatings

    Science.gov (United States)

    Wang, Y. J.; Xu, J. Y.; Zhao, Q. H.; Wang, Y.; Gao, B.

    2017-06-01

    To investigate effects of various power process parameters on deposition efficiency, Al2O3-40% wt. TiO2 is selected as raw material to be coated on Q235 steel substrate by air plasma spraying. Different variables of spraying current and voltage are designed, whose spraying power is from 12.8 KW to 16.8 KW and increment step is 0.8 KW. Deposition thickness is proposed as a simple method to characterize the deposition efficiency of coatings. Analysis of variance is used to observe the difference between two adjacent groups. It is shown that deposition efficiency increases with the increase of spraying current; by and large, it firstly rises and then decreases with the increment of spraying voltage. However, the effects of increasing the latter are much stronger on deposition efficiency.

  1. The effect of spraying parameters on micro-structural properties of WC-12%Co coating deposited on copper substrate by HVOF process

    Energy Technology Data Exchange (ETDEWEB)

    Sathwara, Nishit, E-mail: nishit-25@live.in [Fusion Rector Material Development & Characterization Division, Institute for Plasma Research, GIDC Electronics Estate, Sec-25, Gandhinagar-382016 (India); Metallurgical & Materials Engineering Department, Indus University, Ahmedabad-382115 (India); Jariwala, C., E-mail: chetanjari@yahoo.com; Chauhan, N.; Raole, P. M. [Fusion Rector Material Development & Characterization Division, Institute for Plasma Research, GIDC Electronics Estate, Sec-25, Gandhinagar-382016 (India); Basa, D. K. [Metallurgical & Materials Engineering Department, Indus University, Ahmedabad-382115 (India)

    2015-08-28

    High Velocity Oxy-Fuel (HVOF) thermal sprayed coatingmade from Tungsten Carbide (WC) isconsidered as one of the most durable materials as wear resistance for industrial applications at room temperature. WC coating offers high wear resistance due to its high hardness and tough matrix imparts. The coating properties strongly depend on thermal spray processing parameters, surface preparation and surface finish. In this investigation, the effect of variousHVOF process parameters was studied on WC coating properties. The WC-12%Co coating was produced on Copper substrate. Prior to coating, theCopper substrate surface was prepared by grit blasting. WC-12%Co coatings were deposited on Coppersubstrates with varying process parameters such as Oxygen gas pressure, Air pressure, and spraying distance. Microstructure of coating was examined using Scanning Electron Microscope (SEM) and characterization of phasespresentin the coating was examined by X-Ray Diffraction (XRD). Microhardness of all coatingswas measured by VickerMicrohardness tester. At low Oxygen Pressure(10.00 bar), high Air pressure (7bar) and short nozzle to substrate distance of 170mm, best coating adhesion and porosity less structure isachieved on Coppersubstrate.

  2. Electrolytic Plasma Processing for Sequential Cleaning and Coating Deposition for Cadmium Plating Replacement

    Science.gov (United States)

    2008-08-01

    Al(OH)3 precipitation pH≈5 to 8. Bulk pH of 0.1M aluminium sulphate solution is about 3.5, and it is further reduced due to collateral hydrogen...a surface. For cleaning, the electrolyte can be a simple sodium bicarbonate solution (typically 10%) or ammonium chloride. As measured by SEM and...reduction of the metallic ions. Sodium sulphate and Al powder was added in the bath for one experiment and produced a more uniform coating. The intention

  3. Deposition and Investigation of Hydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Safonov Aleksey

    2015-01-01

    Full Text Available The fluoropolymer coatings of different morphologies are deposited by the HWCVD (Hot Wire CVD method. The effect of activator filament temperature on the structure of fluoropolymer coating is shown. The results of studying the hydrophobic fluoropolymer coatings with different structures, deposited by the HWCVD method, are presented.

  4. Electrochemical deposition of mineralized BSA/collagen coating.

    Science.gov (United States)

    Zhuang, Junjun; Lin, Jun; Li, Juan; Wang, Huiming; Cheng, Kui; Weng, Wenjian

    2016-09-01

    In this work, mineralized collagen coatings with different loading quantity of bovine serum albumin (BSA) were prepared via in situ electrochemical deposition on titanium substrate. The microstructure and BSA loading quantity of the coatings could be controlled by the electrochemical deposition parameters, such as deposition potential, BSA concentration and its adding sequence in the electrolyte. The BSA loading quantity in the coatings was obtained in the range of 0.0170-0.173mg/cm(2), enhancing the cell adhesion and proliferation of the coatings with the simultaneous release. The distinct release behaviors of BSA were attributed to their gradient distribution with different mineralization degrees, which could be adjusted by the deposition process. These results suggest that in situ electrochemical deposition is a promising way to incorporate functional molecules into the mineralized collagen coatings and the mineralized BSA/collagen coatings are highly promising for improving the rhBMP-2 loading capability (1.8-fold).

  5. Large-area bi-component processing of organic semiconductors by spray deposition and spin coating with orthogonal solvents

    Energy Technology Data Exchange (ETDEWEB)

    Treossi, Emanuele; Liscio, Andrea; Palermo, Vincenzo [Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattivita, Bologna (Italy); Feng, Xinliang; Muellen, Klaus [Max-Planck Institute for Polymer Research, Mainz (Germany); Samori, Paolo [Universite Louis Pasteur, Nanochemistry Laboratory, ISIS-CNRS, Strasbourg (France); Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattivita, Bologna (Italy)

    2009-04-15

    Micrometre-thick uniform layers of a polymeric semiconductor (poly(3-hexylthiophene), P3HT) have been fabricated from solution by spray deposition making use of a commercial airbrush. Multi-scale characterization by optical microscopy and atomic force microscopy revealed the formation of smooth layers featuring reproducible patterns of spatially correlated micron-sized holes. This morphology was found to be uniform over the whole sample surface, on millimetre scale. On this micro-patterned P3HT layer an orthogonal solvent (i.e. a solvent which does not dissolve the P3HT) has been employed to deposit either by spin coating or by drop casting a second organic semiconductor. While spin-coated films exhibited nano-crystals of an alkylated perylene tetracarboxy diimide (PDI) preferentially grown into the micro-fabricated holes, drop-cast films displayed crystalline PDI fibres adsorbed on the patterned surface in random positions. (orig.)

  6. Large-area bi-component processing of organic semiconductors by spray deposition and spin coating with orthogonal solvents

    Science.gov (United States)

    Treossi, Emanuele; Liscio, Andrea; Feng, Xinliang; Palermo, Vincenzo; Müllen, Klaus; Samorì, Paolo

    2009-04-01

    Micrometre-thick uniform layers of a polymeric semiconductor (poly(3-hexylthiophene), P3HT) have been fabricated from solution by spray deposition making use of a commercial airbrush. Multi-scale characterization by optical microscopy and atomic force microscopy revealed the formation of smooth layers featuring reproducible patterns of spatially correlated micron-sized holes. This morphology was found to be uniform over the whole sample surface, on millimetre scale. On this micro-patterned P3HT layer an orthogonal solvent (i.e. a solvent which does not dissolve the P3HT) has been employed to deposit either by spin coating or by drop casting a second organic semiconductor. While spin-coated films exhibited nano-crystals of an alkylated perylene tetracarboxy diimide (PDI) preferentially grown into the micro-fabricated holes, drop-cast films displayed crystalline PDI fibres adsorbed on the patterned surface in random positions.

  7. Characteristics of CrAlSiN + DLC coating deposited by lateral rotating cathode arc PVD and PACVD process

    Science.gov (United States)

    Lukaszkowicz, Krzysztof; Sondor, Jozef; Balin, Katarzyna; Kubacki, Jerzy

    2014-09-01

    Coating system composed of CrAlSiN film covered by diamond-like carbon (DLC)-based lubricant, deposited on hot work tool steel substrate was the subject of the research. The CrAlSiN and DLC layers were deposited by PVD lateral rotating ARC-cathodes (LARC) and PACVD technology on the X40CrMoV5-1 respectively. HRTEM investigation shows an amorphous character of DLC layer. It was found that the tested CrAlSiN layer has a nanostructural character with fine crystallites while their average size is less than 10 nm. Based on the XRD pattern of the CrAlSiN, the occurrence of fcc phase was only observed in the coating, the texture direction is perpendicular to the sample surface. Combined SEM, AES and ToF-SIMS studies confirmed assumed chemical composition and layered structure of the coating. The chemical distribution of the elements inside the layers and at the interfaces was analyzed by SEM and AES methods. It was shown that additional CrN layer is present between substrate and CrAlSiN coating. The atomic concentration of the particular elements of DLC and CrAlSiN layer was calculated from the XPS measurements. In sliding dry friction conditions the friction coefficient for the investigated elements is set in the range between 0.05 and 0.07. The investigated coating reveals high wear resistance. The coating demonstrated a dense cross-sectional morphology as well as good adhesion to the substrate.

  8. A Study of Deposition Coatings Formed by Electroformed Metallic Materials.

    Directory of Open Access Journals (Sweden)

    Shoji Hayashi

    Full Text Available Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface treatment is clinically evaluated by peeling and flex tests. However, these testing methods are not ideal for deposition coating strength measurement of electroformed metals. There have been no studies on the deposition coating strength and methods to test electroformed metals. We developed a new deposition coating strength test for electroformed metals. The influence of the negative electrolytic method, which is one of the electrochemical surface treatments, on the strength of the deposition coating of electroformed metals was investigated, and the following conclusions were drawn: 1. This process makes it possible to remove residual deposits on the electrodeposited metal surface layer. 2. Cathode electrolysis is a simple and safe method that is capable of improving the surface treatment by adjustments to the current supply method and current intensity. 3. Electrochemical treatment can improve the deposition coating strength compared to the physical or chemical treatment methods. 4. Electro-deposition coating is an innovative technique for the deposition coating of electroformed metal.

  9. Electrochemical deposition of mineralized BSA/collagen coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Junjun [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Lin, Jun; Li, Juan; Wang, Huiming [The First Affiliated Hospital of Medical College, Zhejiang University, Hangzhou 310003 (China); Cheng, Kui [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Weng, Wenjian, E-mail: wengwj@zju.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); The Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2016-09-01

    In this work, mineralized collagen coatings with different loading quantity of bovine serum albumin (BSA) were prepared via in situ electrochemical deposition on titanium substrate. The microstructure and BSA loading quantity of the coatings could be controlled by the electrochemical deposition parameters, such as deposition potential, BSA concentration and its adding sequence in the electrolyte. The BSA loading quantity in the coatings was obtained in the range of 0.0170–0.173 mg/cm{sup 2}, enhancing the cell adhesion and proliferation of the coatings with the simultaneous release. The distinct release behaviors of BSA were attributed to their gradient distribution with different mineralization degrees, which could be adjusted by the deposition process. These results suggest that in situ electrochemical deposition is a promising way to incorporate functional molecules into the mineralized collagen coatings and the mineralized BSA/collagen coatings are highly promising for improving the rhBMP-2 loading capability (1.8-fold). - Highlights: • BSA is incorporated into mineralized collagen coating by electrochemical deposition. • The loading amount of BSA in coatings can be adjusted in the range of 0-173 ng. • The BSA/collagen coating shows good cytocompatibility with free-albumin culture. • The incorporation process is put forward for some other molecules deposition.

  10. Coating of calcium phosphate on biometallic materials by electrophoretic deposition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Er-lin; YANG Ke

    2005-01-01

    Although biometallic materials have been used as bone implant materials for a long time, they are still detected as foreign bodies by human immune system. Calcium phosphate coating, especially hydroxyapatite(HA)coating attracts special attention due to its good biocompatibility. Being one of the effective methods used to deposit HA coating onto the metallic implant, the electrophoretic deposition(EPD) was reviewed in detail, including the process of EPD, the advantages and disadvantages, the important processing factors and the microstructure and mechanical properties of the coating. Research results on the processing and the coating show potential application of EPD process to the biomedical materials surface modification. In addition, the nanoparticulate HA coating as a new trend in HA coating was also introduced.

  11. Deposition and Coating Properties on CVD Tungsten

    Institute of Scientific and Technical Information of China (English)

    DU Ji-hong; LI Zheng-xiang; LIU Gao-jian; ZHOU Hui-Huang; CHUN liang

    2004-01-01

    Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.

  12. Sputtering process and apparatus for coating powders

    Science.gov (United States)

    Makowiecki, Daniel M.; Kerns, John A.; Alford, Craig S.; McKernan, Mark A.

    2002-01-01

    A process and apparatus for coating small particles and fibers. The process involves agitation by vibrating or tumbling the particles or fibers to promote coating uniformly, removing adsorbed gases and static charges from the particles or fibers by an initial plasma cleaning, and coating the particles or fibers with one or more coatings, a first coating being an adhesion coating, and with subsequent coatings being deposited in-situ to prevent contamination at layer interfaces. The first coating is of an adhesion forming element (i.e. W, Zr, Re, Cr, Ti) of a 100-10,000 .ANG. thickness and the second coating or final coating of a multiple (0.1-10 microns) being Cu or Ag, for example for brazing processes, or other desired materials that defines the new surface related properties of the particles. An essential feature of the coating process is the capability to deposit in-situ without interruption to prevent the formation of a contaminated interface that could adversely affect the coating adhesion. The process may include screening of the material to be coated and either continuous or intermittent vibration to prevent agglomeration of the material to be coated.

  13. Comparative characteristic and erosion behavior of NiCr coatings deposited by various high-velocity oxyfuel spray processes

    Science.gov (United States)

    Sidhu, Hazoor Singh; Sidhu, Buta Singh; Prakash, S.

    2006-12-01

    The purpose of this study is to analyze and compare the mechanical properties and microstructure details at the interface of high-velocity oxyfuel (HVOF)-sprayed NiCr-coated boiler tube steels, namely ASTM-SA-210 grade A1, ASTM-SA213-T-11, and ASTM-SA213-T-22. Coatings were developed by two different techniques, and in these techniques liquefied petroleum gas was used as the fuel gas. First, the coatings were characterized by metallographic, scanning electron microscopy/energy-dispersive x-ray analysis, x-ray diffraction, surface roughness, and microhardness, and then were subjected to erosion testing. An attempt has been made to describe the transformations taking place during thermal spraying. It is concluded that the HVOF wire spraying process offers a technically viable and cost-effective alternative to HVOF powder spraying process for applications in an energy generation power plant with a point view of life enhancement and to minimize the tube failures because it gives a coating having better resistance to erosion.

  14. High-throughput analysis for preparation, processing and analysis of TiO{sub 2} coatings on steel by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cuadrado Gil, Marcos, E-mail: Marcos.cuadradogil@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Van Driessche, Isabel, E-mail: Isabel.VanDriessche@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Van Gils, Sake, E-mail: Sake.Vangils@arcelormittal.com [OCAS - ArcelorMittal Gent R and D Centre, Pres. J.F. Kennedylaan 3, Zelzate B-9060 (Belgium); Lommens, Petra, E-mail: Petra.Lommens@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium); Castelein, Pieter, E-mail: Pieter.Castelein@flamac.be [Flamac - A Division of SIM, Technologiepark 903, Zwijnaarde 9052 (Belgium); De Buysser, Klaartje, E-mail: Klaartje.DeBuysser@ugent.be [SCRIPTS - Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3) (Belgium)

    2012-11-05

    Highlights: Black-Right-Pointing-Pointer High-throughput preparation of TiO{sub 2} aqueous precursors. Black-Right-Pointing-Pointer Analysis of stability and surface tension. Black-Right-Pointing-Pointer Deposition of TiO{sub 2} coatings. - Abstract: A high-throughput preparation, processing and analysis of titania coatings prepared by chemical solution deposition from water-based precursors at low temperature ( Almost-Equal-To 250 Degree-Sign C) on two different types of steel substrates (Aluzinc Registered-Sign and bright annealed) is presented. The use of the high-throughput equipment allows fast preparation of multiple samples saving time, energy and material; and helps to test the scalability of the process. The process itself includes the use of IR curing for aqueous ceramic precursors and possibilities of using UV irradiation before the final sintering step. The IR curing method permits a much faster curing step compared to normal high temperature treatments in traditional convection devices (i.e., tube furnaces). The formulations, also prepared by high-throughput equipment, are found to be stable in the operational pH range of the substrates (6.5-8.5). Titanium alkoxides itself lack stability in pure water-based environments, but the presence of the different organic complexing agents prevents it from hydrolysis and precipitation reactions. The wetting interaction between the substrates and the various formulations is studied by the determination of the surface free energy of the substrates and the polar and dispersive components of the surface tension of the solutions. The mild temperature program used for preparation of the coatings however does not lead to the formation of pure crystalline material, necessary for the desired photocatalytic and super-hydrophilic behavior of these coatings. Nevertheless, some activity can be reported for these amorphous coatings by monitoring the discoloration of methylene blue in water under UV irradiation.

  15. Laboratory and Performance Studies of Anti-wear Coatings Deposited on Nitrided Surfaces of Tools used in an Industrial Hot Die Forging Process

    Science.gov (United States)

    Hawryluk, Marek; Widomski, Paweł; Smolik, Jerzy; Kaszuba, Marcin; Ziemba, Jacek; Gronostajski, Zbigniew

    2017-04-01

    The paper presents the results of laboratory studies performed on produced anti-wear coatings as well as the results of performance tests conducted on tools with these coatings in industrial conditions, in the process of hot die forging. Three different coatings were selected: AlCrTiSiN, Cr/CrN and AlCrTiN, deposited by means of the vacuum-arc method on test samples as well as forging tools used in the hot forging process of a lid. The first part of the paper discusses the results of the studies performed in laboratory conditions, which included: surface morphology by means of SEM, hardness and Young modulus measurements, determination of the chemical composition by means of the EDS method, adhesion tests by means of the scratch method and tribological tests by means of the ball-on-disk method. The obtained results were correlated and applied in the analysis of the performance tests on forging punches with these coatings at an early stage of their performance (up to 4000 produced forgings), which were tested on 19 tools, of which 3 representatives were selected for each coating. A thorough analysis was performed of the wear phenomena and mechanisms and the manner of wear of hybrid layers as well as their resistance to the particular destructive mechanisms. Based on the performed laboratory and performance studies as well as their analysis, it was possible to select the optimal hybrid layer, which enables an increase in the durability of forging tools used in industrial hot die forging processes. The preliminary results showed that the best results for the whole working surface of the tool were obtained for the Cr/CrN layer, which characterizes in high adhesion as well as a lower Young modulus and hardness. In the case of high pressures and the correlated friction, better results were obtained for the AlCrTiN coating, which, besides its good adhesion properties, also exhibited the highest frictional resistance.

  16. Electro-Spark Deposited Coatings for Replacement of Chrome Electroplating

    Science.gov (United States)

    2005-06-01

    Wear and Corrosion: the Electrospark Deposition Process", published in Proceedings, American Electroplaters and Surface Finishers Society, Jan. 2002. 6...Johnson, R.N., " ElectroSpark Deposition : Principals and Applications", Society of Vacuum Coaters 45th Annual Technical Conference Proceedings, Apr...AD AD-E403 050 Contractor Report ARAET-CR-05002 ELECTRO-SPARK DEPOSITED COATINGS FOR REPLACEMENT OF CHROME PLATING R. N. Johnson J. A. Bailey Pacific

  17. Electro-spark deposited coatings for protection of materials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.N. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1995-08-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The coating is fused (metallurgically bonded) to the substrate with such a low total heat input that the bulk substrate material remains at or near ambient temperature. Rapid solidification of the deposit typically results in an extremely fine-grained deposit that may be amorphous for some materials. Nearly any electrically conductive metal, alloy or cermet can be applied to metallic substrates. The ESD process allows multi-layer coatings to be built-up using different materials to create graded structures or surface compositions that would be difficult to achieve by other means. A series of iron-aluminide coatings based on Fe{sub 3}Al and FeAl in combination with refractory metal diffusion-barrier coatings and supplementary additions of other elements are in corrosion testing at ANL. The most recent FeAl coatings are showing a factor of three better corrosion performance than the best previous coatings. Technology transfer activities are a significant portion of the ESD program effort. Notable successes now include the start-up of a new business to commercialize the ESD technology, major new applications in gas turbine engines and steam turbine blade coatings, and in military, medical, metal-working, and recreational equipment applications.

  18. Multilayer Coating Formation at the Deposition from Plasma

    OpenAIRE

    Shanin, Sergei Aleksandrovich; Knyazeva, Anna Georgievna

    2016-01-01

    The numerical experiment was carried out for the process of the coating composition formation during deposition from plasma. The chemical reactions between elements are taken into account. The nonuniform composition of the coating is determined by various transfer processes, including diffusion under stress action. To find the stress field the equilibrium problem was solved numerically because all physical and mechanical properties depend on composition. Stress field has been also obtained no...

  19. Study of barrier properties and chemical resistance of recycled PET coated with amorphous carbon through a plasma enhanced chemical vapour deposition (PECVD) process.

    Science.gov (United States)

    Cruz, S A; Zanin, M; Nerin, C; De Moraes, M A B

    2006-01-01

    Many studies have been carried out in order to make bottle-to-bottle recycling feasible. The problem is that residual contaminants in recycled plastic intended for food packaging could be a risk to public health. One option is to use a layer of virgin material, named functional barrier, which prevents the contaminants migration process. This paper shows the feasibility of using polyethylene terephthalate (PET) recycled for food packaging employing a functional barrier made from hydrogen amorphous carbon film deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) process. PET samples were deliberately contaminated with a series of surrogates using a FDA protocol. After that, PET samples were coated with approximately 600 and 1200 Angstrons thickness of amorphous carbon film. Then, the migration tests using as food simulants: water, 10% ethanol, 3% acetic acid, and isooctane were applied to the sample in order to check the chemical resistance of the new coated material. After the tests, the liquid extracts were analysed using a solid-phase microextraction device (SPME) coupled to GC-MS.

  20. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    Energy Technology Data Exchange (ETDEWEB)

    Purandare, Yashodhan, E-mail: Y.Purandare@shu.ac.uk; Ehiasarian, Arutiun; Hovsepian, Papken [Nanotechnology Centre for PVD Research, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Santana, Antonio [Ionbond AG Olten, Industriestrasse 211, CH-4600 Olten (Switzerland)

    2014-05-15

    Zirconium nitride (ZrN) coatings were deposited on 1 μm finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5 μm with hardness in the range of 30–40 GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  1. Double-Layer Gadolinium Zirconate/Yttria-Stabilized Zirconia Thermal Barrier Coatings Deposited by the Solution Precursor Plasma Spray Process

    Science.gov (United States)

    Jiang, Chen; Jordan, Eric H.; Harris, Alan B.; Gell, Maurice; Roth, Jeffrey

    2015-08-01

    Advanced thermal barrier coatings (TBCs) with lower thermal conductivity, increased resistance to calcium-magnesium-aluminosilicate (CMAS), and improved high-temperature capability, compared to traditional yttria-stabilized zirconia (YSZ) TBCs, are essential to higher efficiency in next generation gas turbine engines. Double-layer rare-earth zirconate/YSZ TBCs are a promising solution. From a processing perspective, solution precursor plasma spray (SPPS) process with its unique and beneficial microstructural features can be an effective approach to obtaining the double-layer microstructure. Previously durable low-thermal-conductivity YSZ TBCs with optimized layered porosity, called the inter-pass boundaries (IPBs) were produced using the SPPS process. In this study, an SPPS gadolinium zirconate (GZO) protective surface layer was successfully added. These SPPS double-layer TBCs not only retained good cyclic durability and low thermal conductivity, but also demonstrated favorable phase stability and increased surface temperature capabilities. The CMAS resistance was evaluated with both accumulative and single applications of simulated CMAS in isothermal furnaces. The double-layer YSZ/GZO exhibited dramatic improvement in the single application, but not in the continuous one. In addition, to explore their potential application in integrated gasification combined cycle environments, double-layer TBCs were tested under high-temperature humidity and encouraging performance was recorded.

  2. Fabrication of barium titanate nanoparticles/poly (methylmethacrylate composite films by a combination of deposition process and spin-coating technique

    Directory of Open Access Journals (Sweden)

    Yoshio Kobayashi

    2014-10-01

    Full Text Available The present work proposes a method for fabricating poly(methylmethacrylate (PMMA film containing barium titanate (BT nanoparticles (BT/PMMA film. BT particles with an average size of 77.6 ± 30.5 nm and a crystal size of 28.1 nm were synthesized by adding sodium hydroxide aqueous solution to titanium tetraisopropoxide/acetylacetone/i-propanol solution suspending barium hydroxide. A sodium glass plate, of which surface was modified with polyvinylpyrrolidone, was immersed into water suspending the BT particles, which resulted in deposition of the BT particles on the plate. A BT/PMMA film was fabricated by twice performance of a process composed of spin-coating of N-methyl-2-pyrrolidone (NMP dissolving PMMA on the plate, and then drying the coated plate in the atmosphere at room temperature. Spin-coating of a PMMA/NMP solution with a PMMA concentration of 150 g/L at a rotating speed of 5000 rpm provided fabrication of a BT/PMMA film with a BT volume fraction of 35.5%, a thickness of ca. 300 nm, and a transmittance of ca. 90% in the visible light region.

  3. Microwave plasma deposition of diamond like carbon coatings

    Science.gov (United States)

    Patil, D. S.; Ramachandran, K.; Venkataramani, N.; Pandey, M.; D'Cunha, R.

    2000-11-01

    he promising applications of the microwave plasmas have been appearing in the fields of chemical processes and semiconductor manufacturing. Applications include surface deposition of all types including diamond/diamond like carbon (DLC) coatings, etching of semiconductors, promotion of organic reactions, etching of polymers to improve bonding of the other materials etc. With a 2.45 GHz, 700 W, microwave induced plasma chemical vapor deposition (CVD) system set up in our laboratory we have deposited diamond like carbon coatings. The microwave plasma generation was effected using a wave guide single mode applicator. We have deposited DLC coatings on the substrates like stainless steel, Cu--Be, Cu and Si. The deposited coatings have been characterized by FTIR, Raman spectroscopy and ellipsometric techniques. The results show that we have achieved depositing ~ 95% sp3 bonded carbon in the films. The films are uniform with golden yellow color. The films are found to be excellent insulators. The ellipsometric measurements of optical constant on silicon substrates indicate that the films are transparent above 900 nm.

  4. Chemical vapor deposition coatings for oxidation protection of titanium alloys

    Science.gov (United States)

    Cunnington, G. R.; Robinson, J. C.; Clark, R. K.

    1991-01-01

    Results of an experimental investigation of the oxidation protection afforded to Ti-14Al-21Nb and Ti-14Al-23Nb-2V titanium aluminides and Ti-17Mo-3Al-3Nb titanium alloy by aluminum-boron-silicon and boron-silicon coatings are presented. These coatings are applied by a combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. The former is for the application of aluminum, and the latter is for codeposition of boron and silicon. Coating thickness is in the range of 2 to 7 microns, and coating weights are 0.6 to 2.0 mg/sq cm. Oxidation testing was performed in air at temperatures to 1255 K in both static and hypersonic flow environments. The degree of oxidation protection provided by the coatings is determined from weight change measurements made during the testing and post test compositional analyses. Temperature-dependent total normal emittance data are also presented for four coating/substrate combinations. Both types of coatings provided excellent oxidation protection for the exposure conditions of this investigation. Total normal emittances were greater than 0.80 in all cases.

  5. Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    D H Jung; B Park; J J Lee

    2004-01-01

    Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

  6. Improving hardness of electroless Ni-B coatings using optimized deposition conditions and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Oraon, B. [Department of Mechanical Engineering, Jadavpur University, Kolkata 700 032 (India)], E-mail: b_oraon_65@yahoo.co.in; Majumdar, G. [Department of Mechanical Engineering, Jadavpur University, Kolkata 700 032 (India); Ghosh, B. [Advanced Materials and Solar Photovoltaic Division, School of Energy Studies, Jadavpur University, Kolkata 700 032 (India)

    2008-07-01

    The alkaline borohydride-reduced bath has been used to deposit electroless nickel-boron (Ni-B) coatings on a pure (99.99%) copper substrate. The hardness of the Ni-B coatings has been improved using optimized deposition conditions and thereafter by annealing. The electroless Ni-B deposition per unit area has been considered as the response variable and response surface method (RSM) has been used to optimize the process parameters and the deposition per unit area. The electroless Ni-B coatings have again been formed at the optimized deposition conditions and the as-deposited coating hardness has been evaluated using an empirical model and regression analysis. It has been observed that there is a significant improvement in as-deposited coating hardness. The Ni-B coated specimens formed at optimized deposition conditions have also been annealed at different temperatures ranging from 100 deg. C to 500 deg. C. The hardness of the annealed specimens has been estimated for different annealing temperatures and has been observed that the coating hardness increases with annealing temperature and then further increase in annealing temperature reduces the coating hardness. The coating hardness becomes the highest for annealing temperature of about 300 deg. C. Both the as-deposited and annealed coating hardness have been observed to be significantly higher than that reported by many researchers for electroless Ni-B coatings.

  7. Oleophobic optical coating deposited by magnetron PVD

    Science.gov (United States)

    Bernt, D.; Ponomarenko, V.; Pisarev, A.

    2016-09-01

    Thin oxinitride films of Zn-Sn-O-N and Si-Al-O-N were deposited on glass by reactive magnetron sputtering at various nitrogen-to-oxygen ratios. Nitrogen added to oxygen led to decrease of the surface roughness and increase of oleophobic properties studied by the oil-drop test. The best oleophobity was obtained for Zn-Sn-O-N oxinitride at Zn:Sn=1:1 and N:O=1:2. Improved oleophobic properties were also demonstrated if the oxinitride film was deposited on top of the multilayer coating as the final step in the industrial cycle of production of energy efficient glass.

  8. Plasma sprayed and electrospark deposited zirconium metal diffusion barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hollis, Kendall J [Los Alamos National Laboratory; Pena, Maria I [Los Alamos National Laboratory

    2010-01-01

    Zirconium metal coatings applied by plasma spraying and electrospark deposition (ESD) have been investigated for use as diffusion barrier coatings on low enrichment uranium fuel for research nuclear reactors. The coatings have been applied to both stainless steel as a surrogate and to simulated nuclear fuel uranium-molybdenum alloy substrates. Deposition parameter development accompanied by coating characterization has been performed. The structure of the plasma sprayed coating was shown to vary with transferred arc current during deposition. The structure of ESD coatings was shown to vary with the capacitance of the deposition equipment.

  9. Conversion Coatings for Aluminum Alloys by Chemical Vapor Deposition Mechanisms

    Science.gov (United States)

    Reye, John T.; McFadden, Lisa S.; Gatica, Jorge E.; Morales, Wilfredo

    2004-01-01

    With the rise of environmental awareness and the renewed importance of environmentally friendly processes, the United States Environmental Protection Agency has targeted surface pre-treatment processes based on chromates. Indeed, this process has been subject to regulations under the Clean Water Act as well as other environmental initiatives, and there is today a marked movement to phase the process out in the near future. Therefore, there is a clear need for new advances in coating technology that could provide practical options for replacing present industrial practices. Depending on the final application, such coatings might be required to be resistant to corrosion, act as chemically resistant coatings, or both. This research examined a chemical vapor deposition (CVD) mechanism to deposit uniform conversion coatings onto aluminum alloy substrates. Robust protocols based on solutions of aryl phosphate ester and multi-oxide conversion coating (submicron) films were successfully grown onto the aluminum alloy samples. These films were characterized by X-ray Photoelectron Spectroscopy (XPS). Preliminary results indicate the potential of this technology to replace aqueous-based chromate processes.

  10. Deposition and Characterization of TRISO Coating Layers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. K.; Choi, D. J.; Lee, H. K.; Kim, J. K.; Kim, J. H.; Chun, J. H. [KAIST, Daejeon (Korea, Republic of)

    2007-03-15

    Zirconium carbide has been chosen and studied as an advanced material of silicon carbide. In order to collect data on the basic properties and characteristics of Zirconium carbide, studies have been conducted using various methods. As a result of chemically vapor deposed subliming zirconium tetrachloride(ZrCl4) and using methane(CH4) as a source in hydrogen atmosphere, graphite film is deposited.. Zirconium carbide was deposited on the sample where silicon carbide was deposited on a graphite substrate using Zirconium sponge as a Zirconium source. In terms of physical characteristics, the deposited Zirconium carbide showed higher strength, but slightly lower elastic modulus than silicon carbide. In order to evaluate the mechanical properties of a coating layer in pre-irradiation step, internal pressure induced method and direct strength measurement method is carried out. In the internal pressure induced method, in order to produce the requirement pressure, pressure media is used. In the direct strength measurement method, the indentation experiment that indent on a hemisphere shell with plate indenter is conducted. For this method, the finite element analysis is used and the analysis is verified by indentation experiments. To measure the strength of TRISO particle SiC coating, SiC hemisphere shell is performed through grinding and heat treatment. Through the finite element analysis, strength evaluation equation is suggested. Using suggested equation, Strength evaluation is performed and the strength value shows 1025MPa as a result of statistical analysis.

  11. Synthesis of mullite coatings by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mulpuri, R.P.; Auger, M.; Sarin, V.K. [Boston Univ., MA (United States)

    1996-08-01

    Formation of mullite on ceramic substrates via chemical vapor deposition was investigated. Mullite is a solid solution of Al{sub 2}O{sub 3} and SiO{sub 2} with a composition of 3Al{sub 2}O{sub 3}{circ}2SiO{sub 2}. Thermodynamic calculations performed on the AlCl{sub 3}-SiCl{sub 4}-CO{sub 2}-H{sub 2} system were used to construct equilibrium CVD phase diagrams. With the aid of these diagrams and consideration of kinetic rate limiting factors, initial process parameters were determined. Through process optimization, crystalline CVD mullite coatings have been successfully grown on SiC and Si{sub 3}N{sub 4} substrates. Results from the thermodynamic analysis, process optimization, and effect of various process parameters on deposition rate and coating morphology are discussed.

  12. Thermal Barrier Coatings Resistant to Glassy Deposits

    Science.gov (United States)

    Drexler, Julie Marie

    Engineering of alloys has for years allowed aircraft turbine engines to become more efficient and operate at higher temperatures. As advancements in these alloy systems have become more difficult, ceramic thermal barrier coatings (TBCs), often yttria (7 wt %) stabilized zirconia (7YSZ), have been utilized for thermal protection. TBCs have allowed for higher engine operating temperatures and better fuel efficiency but have also created new engineering problems. Specifically, silica based particles such as sand and volcanic ash that enter the engine during operation form glassy deposits on the TBCs. These deposits can cause the current industrial 7YSZ thermal barrier coatings to fail since the glass formed penetrates and chemically interacts with the TBC. When this occurs, coating failure may occur due to a loss of strain tolerance, which can lead to fracture, and phase changes of the TBC material. There have been several approaches used to stop calcium-magnesium aluminio-silcate (CMAS) glasses (molten sand) from destroying the entire TBC, but overall there is still limited knowledge. In this thesis, 7YSZ and new TBC materials will be examined for thermochemical and thermomechanical performance in the presence of molten CMAS and volcanic ash. Two air plasma sprayed TBCs will be shown to be resistant to volcanic ash and CMAS. The first type of coating is a modified 7YSZ coating with 20 mol% Al2O3 and 5 mol% TiO2 in solid solution (YSZ+20Al+5Ti). The second TBC is made of gadolinium zirconate. These novel TBCs impede CMAS and ash penetration by interacting with the molten CMAS or ash and drastically changing the chemistry. The chemically modified CMAS or ash will crystallize into an apatite or anorthite phase, blocking the CMAS or ash from further destroying the coating. A presented mechanism study will show these coatings are effective due to the large amount of solute (Gd, Al) in the zirconia structure, which is the key to creating the crystalline apatite or

  13. Initiated chemical vapor deposition of antimicrobial polymer coatings.

    Science.gov (United States)

    Martin, T P; Kooi, S E; Chang, S H; Sedransk, K L; Gleason, K K

    2007-02-01

    The vapor phase deposition of polymeric antimicrobial coatings is reported. Initiated chemical vapor deposition (iCVD), a solventless low-temperature process, is used to form thin films of polymers on fragile substrates. For this work, finished nylon fabric is coated by iCVD with no affect on the color or feel of the fabric. Infrared characterization confirms the polymer structure. Coatings of poly(dimethylaminomethyl styrene) of up to 540 microg/cm2 were deposited on the fabric. The antimicrobial properties were tested using standard method ASTM E2149-01. A coating of 40 microg/cm2 of fabric was found to be very effective against gram-negative Escherichia coli, with over a 99.99%, or 4 log, kill in just 2 min continuing to over a 99.9999%, or 6 log, reduction in viable bacteria in 60 min. A coating of 120 microg/cm2 was most effective against the gram-positive Bacillus subtilis. Further tests confirmed that the iCVD polymer did not leach off the fabric.

  14. Performance of chromium nitride based coatings under plastic processing conditions

    OpenAIRE

    Cunha, l.; Andritschky, M.; Pischow, K.; Wang, Z.(Institute of High Energy Physics, Beijing, China); Zarychta, A.; Miranda, A. S.; A.M. Cunha

    2000-01-01

    Chromium nitride based coatings were produced in the form of monolithic and multilayer coatings, by DC and RF reactive magnetron sputtering. These coatings were deposited onto stainless steel and tool steel substrates. Chromium nitride coatings have;proved to be wear and corrosion resistant. The combination of these characteristics was necessary to protect surfaces during plastic processing. In order to select the best coatings, some mechanical and tribological tests were performed. Har...

  15. Roll-to-roll vacuum deposition of barrier coatings

    CERN Document Server

    Bishop, Charles A

    2015-01-01

    It is intended that the book will be a practical guide to provide any reader with the basic information to help them understand what is necessary in order to produce a good barrier coated web or to improve the quality of any existing barrier product. After providing an introduction, where the terminology is outlined and some of the science is given (keeping the mathematics to a minimum), including barrier testing methods, the vacuum deposition process will be described. In theory a thin layer of metal or glass-like material should be enough to convert any polymer film into a perfect barrier material. The reality is that all barrier coatings have their performance limited by the defects in the coating. This book looks at the whole process from the source materials through to the post deposition handling of the coated material. This holistic view of the vacuum coating process provides a description of the common sources of defects and includes the possible methods of limiting the defects. This enables readers...

  16. Diamond-like carbon and ceramic materials as protective coatings grown by pulsed laser deposition

    OpenAIRE

    Perera Mercado, Yibran Argenis

    2004-01-01

    A rather large number of nitride, carbide, and oxide thin films are used as hard and wear-resistant coatings, for optical, corrosive, and refractory applications that are of crucial importance. Additional requirements place even more stringent conditions on the deposition processes. The properties of coatings deposited by pulsed laser deposition are determined by the deposition parameters, the composition of the PLD plasma and its ionization states, the substrate conditions, etc.. In this way...

  17. Deposition and tribological behaviour of sputtered carbon hard coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.; Camino, D.; Jones, A.H.S.; Teer, D.G. [Teer Coatings Ltd., Hartlebury (United Kingdom)

    2000-02-21

    The exceptional tribological properties of low deposition temperature sputtered carbon coatings (Graphit-iC coatings) have been recently reported. This paper describes the latest development of these coatings and particularly how, by an optimisation of the deposition parameters, it has been possible to obtain relative soft to very hard coatings with extremely low specific wear rates. The coatings have been deposited in a closed field unbalanced magnetron sputter ion plating (CFUBMSIP) installation. By applying the appropriate conditions of deposition, carbon coatings with hardness from 1500 to 4000 HV can be routinely deposited. Preliminary analytical results are presented in order to characterise such hard coatings: high-resolution transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis are some of the different techniques used for this work. Finally, a number of the applications are reported with tribological test results. (orig.)

  18. Effect of Se flux on CuGaSe2 absorbers deposited on ITO-coated SLG substrates by using a three-stage co-evaporation process

    Science.gov (United States)

    Yoo, Jinsu; Eo, Young-Joo; Cho, Jun-Sik; Yun, Jae-Ho; Choi, Jang Hun; Kim, Kihwan; Park, Ju Hyung; Kong, Seong Ho

    2016-11-01

    As the key factor for top-cell application in a tandem structure, wide-bandgap chalcopyrite CuGaSe2 (CGS) absorbers were deposited at a thickness of 2 μm on soda-lime glass (SLG) which was coated with radio-frequency sputtered indium-tin-oxide (ITO) films. The semi-transparent CGS absorbers with a bandgap energy of 1.65 eV were grown by using a three-stage co-evaporation process with Cu, Ga, and Se elemental sources. During CGS absorber growth, the composition ratio [Cu]/[Ga] was fixed at about 0.85 and the Se-to-Ga flux ratio P [ Se]/[ Ga] was varied from 22 to 61 by increasing the temperature of the Se source. In this study, the compositional, structural, optical and electrical properties of top-cell CGS absorbers, which absorbed the short wavelength range of the solar spectrums for tandem solar cell application, were investigated as a function of the Se flux. On the basis of our experimental results, the highest CGS solar cell efficiency of 4.7 % in the cell structure described as Al/ZnO:Al/i-ZnO/CdS/CGS/ITO/SLG was demonstrated using a P [ Se]/[ Ga] value of 22.

  19. Laser deposition of coatings for aeronautical and industrials turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Teleginski, V. [Instituto Federal de Sao Paulo (IFSP), SP (Brazil); Silva, S.A.; Riva, R.; Vasconcelos, G. [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil); Silva Pita, G.R. [Universidade Braz Cubas, Mogi das Cruzes, SP (Brazil); Yamin, L.S. [Escola Tecnica Everardo Passos (ETEP), Sao Jose dos Campos, DP (Brazil)

    2016-07-01

    Full text: Zirconium-based ceramic materials are widely employed as Thermal Barrier Coatings (TBC), due to its excellent wear and corrosion resistance at high temperatures. The application of TBC includes aeronautical and industrials turbine blades. The working conditions include oxidizing environments and temperatures above 1000°C. The zirconium-based ceramics are developed in such a way that the microstructural control is possible through the control of chemical composition, fabrication route and, thermal treatment. The present paper proposes a laser route to deposit the TBC coating, where the microstructural control is a function of power density and interaction time between the laser beam and the material. The main objective of this work is to study the influence of the CO2 laser beam (Synrad Evolution 125) parameters: power density and interaction time, on the deposition process of yttria-stabilized zirconia (YSZ) powders on NiCrAlY/AISI 316L substrates. The resulting coating surface and interface were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The results indicate that is possible to match laser parameters of scanning speed and intensity to produce homogenous coatings. The X-Ray analyses show that the obtained ceramic coating has reduced number of phases, with prevalence of tetragonal phase.(author)

  20. Chemical vapor deposition coating of fibers using microwave application

    Science.gov (United States)

    Barmatz, Martin B. (Inventor); Hoover, Gordon (Inventor); Jackson, Henry W. (Inventor)

    2000-01-01

    Chemical vapor deposition coating is carried out in a cylindrical cavity. The fibers are heated by a microwave source that is uses a TM0N0 mode, where O is an integer, and produces a field that depends substantially only on radius. The fibers are observed to determine their heating, and their position can be adjusted. Once the fibers are uniformly heated, a CVD reagent is added to process the fibers.

  1. Transmission electron microscopy studies of YBCO coated conductors prepared by pulsed-laser deposition and multiple-stage chemical vapor deposition processes

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takeharu [Materials R and D Lab, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan)]. E-mail: tkato@jfcc.or.jp; Sasaki, Hirokazu [Materials R and D Lab, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Iwai, Hiroyuki [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Ibi, Akira [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Kashima, Naoji [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Niwa, Toshiharu [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Muroga, Takemi [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Miyata, Seiki [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Watanabe, Tomonori; Yamada, Yutaka; Izumi, Teruo [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Iijima, Yasuhiro; Kakimoto, Kazuomi; Sutoh, Yasunori [Material Technology Lab, Fujikura Ltd., 1-5-1 Kiba, Koto-ku, Tokyo 135-8512 (Japan); Nagaya, Shigeo [Chubu Electric Power Co., Inc., Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya 459-8522 (Japan); Saitoh, Takashi [Material Technology Lab, Fujikura Ltd., 1-5-1 Kiba, Koto-ku, Tokyo 135-8512 (Japan); Sasaki, Yukichi; Hirayama, Tsukasa [Materials R and D Lab, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan); Shiohara, Yuh [SRL-Nagoya Coated Conductor Center, ISTEC, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan)]|[SRL-Division of Superconducting Tapes and Wires, ISTEC, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Ikuhara, Yuichi [Materials R and D Lab, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587 (Japan)

    2005-10-01

    Three types of YBCO films were deposited on metal tapes with biaxially textured CeO{sub 2}/Gd{sub 2}Zr{sub 2}O{sub 7} multilayer. One YBCO film 4 {mu}m in thickness was formed by pulsed-laser deposition (PLD) on the stationary substrate and another film 3 {mu}m in thickness by PLD using a reel-to-reel substrate tape transferring system. I {sub c} values of the films were 173 A and 293 A, respectively A further film 1 {mu}m in thickness was fabricated by multiple-stage chemical vapor deposition (MSCVD). The I {sub c} value of the MSCVD-YBCO film was 100 A. The microstructures of these YBCO films were characterized using transmission electron microscopy (TEM). In the PLD-YBCO films, the films less than 1 {mu}m thick were predominantly composed of c-axis oriented grains which were considered to grow spirally, however, irregular instances of a-axis oriented grains were also found. The a-axis oriented grains size increased with increasing thickness of the YBCO films. In the 4 {mu}m-thick PLD-YBCO film with an I {sub c} value of 173 A, a-axis oriented grains were considered to nucleate on the CeO{sub 2}. We found many Y{sub 2}O{sub 3} and cupper oxides at the boundaries between a- and c-axes oriented grains and the orientation relationships between YBCO and Y{sub 2}O{sub 3} were determined to be as follows: (0 0 1)YBCO//(0 0 1)Y{sub 2}O{sub 3} and (1 0 0)YBCO//(1 1 0)Y{sub 2}O{sub 3}. We also found many gaps and pores between YBCO grains. Nucleation of a-axis oriented grains was completely suppressed on the CeO{sub 2} in the 3 {mu}m-thick PLD-YBCO film with an I {sub c} value of 293 A. In the MSCVD-YBCO film, the YBCO film mostly consisted of c-axis oriented grains, however a-axis oriented grains and polycrystal also formed in the film. As the MSCVD-YBCO film became thicker, the a-axis oriented grains grew large, as same as in the PLD-YBCO films. The growth rate of a-axis oriented grain along the substrate normal was much higher than that of c-axis oriented grains in

  2. Oxidation Resistance of CVD (Chemical Vapor Deposition) Coatings

    Science.gov (United States)

    1987-02-01

    carbonaceous residuoe were overcome, and dense, iadherent, coat-ings which :ýtop oxidat-ion Of the substrate art! reliably produced. The iridium deposition...flow, pressure and geometry within the reaction chamber, and substrate material. For the coating to have high integrity and adhesion to the substrate...entirely produced by Ultramet using chemical vapor deposition and a novel integrated fabrication technique. Coating the inside of a long chamber presents

  3. A Study on Medium Temperature Chemical Vapor Deposition (MT-CVD) Technology and Super Coating Materials

    Institute of Scientific and Technical Information of China (English)

    GAO Jian; LI Jian-ping; ZENG Xiang-cai; MA Wen-cun

    2004-01-01

    In this paper, the dense and columnar crystalline TiCN coating layers with very good bonding strength between a layer and another layer was deposited using Medium Temperature Chemical Vapor Deposition (MT-CVD) where CH3CN organic composite with C/N atomic clusters etc. was utilized at 700 ~ 900 ℃. Effect of coating processing parameters, such as coating temperature, pressure and different gas flow quantity on structures and properties of TiCN coating layers were investigated. The super coating mechanis mand structures were analyzed. The new coating processing parameters and properties of carbide inserts with super coating layers were gained by using the improved high temperature chemical vapor deposition (HTCVD) equipment and HT-CVD, in combination with MT-CVD technology.

  4. Mechanisms of spallation of electron beam physical vapor deposited thermal barrier coatings with and without platinum aluminide bond coat ridges

    Energy Technology Data Exchange (ETDEWEB)

    Vaidyanathan, K.; Gell, M. [Connecticut Univ., Storrs, CT (United States). Dept. of Metallurgy; Jordan, E. [Dept. Mechanical Engineering, University of Connecticut, CT-06269, Storrs (United States)

    2000-11-01

    Grain boundary ridges, that form on the surface of platinum aluminide [(Ni,Pt)Al] bond coats prior to the deposition of the yttria stabilized zirconia ceramic layer by the electron beam physical vapor deposition (EB-PVD) process, were shown to be the sites for spallation damage initiation in (Ni,Pt)Al/EB-PVD thermal barrier coatings. When these ridges are removed prior to deposition of the ceramic layer, a 3 x life improvement is achieved. This study compares the spallation mechanisms in specimens with and without bond coat ridges, in order to explain the improvement in spallation life. (orig.)

  5. Microstructure and Corrosion Properties of AlCoCrFeNi High Entropy Alloy Coatings Deposited on AISI 1045 Steel by the Electrospark Process

    Science.gov (United States)

    Li, Q. H.; Yue, T. M.; Guo, Z. N.; Lin, X.

    2013-04-01

    Electrospark deposition (ESD) was employed to clad the AlCoCrFeNi high-entropy alloy (HEA) on AISI 1045 carbon steel. The relationship between the microstructure and corrosion properties of the HEA-coated specimens was studied and compared with that of the copper-molded cast HEA material. Two major microstructural differences were found between the cast HEA material and the HEA coatings. First, the cast material comprises both columnar and equiaxed crystals with a columnar-to-equiaxed transition (CET), whereas the HEA coatings consist of an entirely columnar crystal structure. The CET phenomenon was analyzed based on Hunt's criterion. Second, unlike the cast HEA material, there was no obvious Cr-rich interdendritic segregation and nano-sized precipitate distributed within the dendrites of the HEA coating. With regard to corrosion properties, the corrosion current of the HEA-coated specimen was significantly lower than for the 1045 steel and the cast HEA material. This was attributed to the ESD specimen having a relatively high Cr oxide and Al oxide content at the surface. Moreover, for the ESD specimen, the absence of Cr-rich interdendritic phase and second-phase precipitation resulted in a relatively uniform corrosion attack, which is different from the severe galvanic corrosion attack that occurred in the cast specimen.

  6. Atmospheric Plasma Deposition of Diamond-like Carbon Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ladwig, Angela

    2008-01-23

    There is great demand for thin functional coatings in the semiconductor, optics, electronics, medical, automotive and aerospace industries [1-13]. As fabricated components become smaller and more complex, the properties of the materials’ surface take on greater importance. Thin coatings play a key role in tailoring surfaces to give them the desired hardness, wear resistance, chemical inertness, and electrical characteristics. Diamond-like carbon (DLC) coatings possess an array of desirable properties, including outstanding abrasion and wear resistance, chemical inertness, hardness, a low coefficient of friction and exceptionally high dielectric strength [14-22]. Diamond-like carbon is considered to be an amorphous material, containing a mixture of sp2 and sp3 bonded carbon. Based on the percentage of sp3 carbon and the hydrogen content, four different types of DLC coatings have been identified: tetrahedral carbon (ta-C), hydrogenated amorphous carbon (a-C:H) hard, a-C:H soft, and hydrogenated tetrahedral carbon (ta-C:H) [20,24,25]. Possessing the highest hardness of 80 GPa, ta-C possesses an sp3 carbon content of 80 to 88u%, and no appreciable hydrogen content whereas a-C:H soft possesses a hardness of less than 10 GPa, contains an sp3 carbon content of 60% and a hydrogen content between 30 to 50%. Methods used to deposit DLC coatings include ion beam deposition, cathodic arc spray, pulsed laser ablation, argon ion sputtering, and plasma-enhanced chemical vapor deposition [73-83]. Researchers contend that several advantages exist when depositing DLC coatings in a low-pressure environment. For example, ion beam processes are widely utilized since the ion bombardment is thought to promote denser sp3-bonded carbon networks. Other processes, such as sputtering, are better suited for coating large parts [29,30,44]. However, the deposition of DLC in a vacuum system has several disadvantages, including high equipment cost and restrictions on the size and shape of

  7. Chemical Vapor Deposition of Turbine Thermal Barrier Coatings

    Science.gov (United States)

    Haven, Victor E.

    1999-01-01

    Ceramic thermal barrier coatings extend the operating temperature range of actively cooled gas turbine components, therefore increasing thermal efficiency. Performance and lifetime of existing ceram ic coatings are limited by spallation during heating and cooling cycles. Spallation of the ceramic is a function of its microstructure, which is determined by the deposition method. This research is investigating metalorganic chemical vapor deposition (MOCVD) of yttria stabilized zirconia to improve performance and reduce costs relative to electron beam physical vapor deposition. Coatings are deposited in an induction-heated, low-pressure reactor at 10 microns per hour. The coating's composition, structure, and response to the turbine environment will be characterized.

  8. Microstructure and Wear Properties of FeCrC, FeW and Feti Modified Iron Based Alloy Coating Deposited by PTA Process on AISI 430 Steel

    Directory of Open Access Journals (Sweden)

    Teker T.

    2014-10-01

    Full Text Available The plasma transferred arc (PTA process was used for developing wear resistance of AISI 430 steel substrate. Appropriate quantities of FeCrC, FeW and FeTi powders were combined to create conditions that synthesized M7C3 particles into reinforced Fe-based composite surface coating. The phase transformations on new created coated surfaces were comprehensively examined by using a combination of scanning electron microscopy (SEM, microanalysis by energy dispersive spectrometry (EDS, X-Ray diffraction (XRD, microhardness and abrasive wear tests. The microstructure studies of the superficial layers of the coating revealed presence of a mixture of the dendritic phase structure of austenite (γ and fine eutectic M7C3 carbides. The results show that; the concentrations of the elements (Cr, W, Ti added as ferroalloys, the size of dendrites formed in the coated surface, the change of hardness of the coated surfaces, the carbide volume rate and thickness of the coating changed by the variation of the processing parameters (ratio of reinforcement particulates and heat input.

  9. High Energy Radial Deposition of Diamond-Like Carbon Coatings

    Directory of Open Access Journals (Sweden)

    Konrad Suschke

    2015-07-01

    Full Text Available Diamond-like carbon (DLC coatings were deposited with a new direct ion deposition system using a novel 360 degree ion source operating at acceleration voltage between 4 and 8 kV. Cross-sectional TEM images show that the coatings have a three layered structure which originates from changes in the deposition parameters taking into account ion source condition, ion current density, deposition angles, ion sputtering and ion source movement. Varying structural growth conditions can be achieved by tailoring the deposition parameters. The coatings show good promise for industrial use due to their high hardness, low friction and excellent adhesion to the surface of the samples.

  10. Effect of Precipitation on the Microhardness Distribution of Diode Laser Epitaxially Deposited IN718 Alloy Coating

    Institute of Scientific and Technical Information of China (English)

    Yaocheng Zhang; Zhuguo Li; Pulin Nie; Yixiong Wu

    2013-01-01

    The microhardness distribution of the diode laser epitaxially deposited IN718 alloy coating was investigated.The Laves concentration in different regions of the coating was measured by binarization processing.The strengthening phase of the coating was characterized by transmission electron microscopy (TEM).The results showed that the microhardness increased along the depth of the coating.Part of Laves dissolved into austenitic matrix during the successive laser deposition.A little amount of strengthening phase was precipitated in the bottom region of the coating.It was attributed to the heat effect from the thermal cycle of successive deposition on the microstructure in the bottom region of the epitaxially deposited coating.

  11. 仿生法沉积磷灰石层的研究进展%Progress in the Study of Biomimetic Process for Depositing Apatite Coatings

    Institute of Scientific and Technical Information of China (English)

    付涛; 徐可为

    2001-01-01

    仿生法沉积磷灰石层模仿了自然界磷灰石的 沉积过程,为生物材料的研制开辟了新途径。本文对生物模仿沉积磷灰石方法的过程、机制 以及涂层的力学和生物学性能作了介绍。%The biomimetic method, which mimics the natural dep osition of biologic apatite, has opened up a new way to develop biomaterials. Th is paper gives a brief introduction of various biomimetic methods to deposit apatite coatings, and the mechanical and biological properties of the coatings.

  12. Sol-gel deposited electrochromic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, N.; Lampert, C.M.

    1995-06-01

    Electrochromic devices have increasing application in display devices, switchable mirrors and smart windows. A variety of vacuum deposition technologies have been used to make electrochromic devices. The sol- gel process offers an alternative approach to the synthesis of optical quality and low cost electrochromic device layers. This study summarizes the developments in sol-gel deposited electrochromic films. The sol-gel process involves the formation of oxide networks upon hydrolysis-condensation of alkoxide precursors. In this study we cover the sol-gel deposited oxides of WO[sub 3], V[sub 2]O[sub 5], TiO[sub 2], Nb[sub 2]O[sub 5], and NiO[sub x].

  13. Characteristics of TiO2/ZnO bilayer film towards pH sensitivity prepared by different spin coating deposition process

    Science.gov (United States)

    Rahman, Rohanieza Abdul; Zulkefle, Muhammad Al Hadi; Abdullah, Wan Fazlida Hanim; Rusop, M.; Herman, Sukreen Hana

    2016-07-01

    In this study, titanium dioxide (TiO2) and zinc oxide (ZnO) bilayer film for pH sensing application will be presented. TiO2/ZnO bilayer film with different speed of spin-coating process was deposited on Indium Tin Oxide (ITO), prepared by sol-gel method. This fabricated bilayer film was used as sensing membrane for Extended Gate Field-Effect Transistor (EGFET) for pH sensing application. Experimental results indicated that the sensor is able to detect the sensitivity towards pH buffer solution. In order to obtained the result, sensitivity measurement was done by using the EGFET setup equipment with constant-current (100 µA) and constant-voltage (0.3 V) biasing interfacing circuit. TiO2/ZnO bilayer film which the working electrode, act as the pH-sensitive membrane was connected to a commercial metal-oxide semiconductor FET (MOSFET). This MOSFET then was connected to the interfacing circuit. The sensitivity of the TiO2 thin film towards pH buffer solution was measured by dipping the sensing membrane in pH4, pH7 and pH10 buffer solution. These thin films were characterized by using Field Emission Scanning Electron Microscope (FESEM) to obtain the surface morphology of the composite bilayer films. In addition, I-V measurement was done in order to determine the electrical properties of the bilayer films. According to the result obtained in this experiment, bilayer film that spin at 4000 rpm, gave highest sensitivity which is 52.1 mV/pH. Relating the I-V characteristic of the thin films and sensitivity, the sensing membrane with higher conductivity gave better sensitivity.

  14. Investigation of coatings of austenitic steels produced by supersonic laser deposition

    Science.gov (United States)

    Gorunov, A. I.; Gilmutdinov, A. Kh.

    2017-02-01

    The structure and properties of stainless austenitic steel coatings obtained by the supersonic laser deposition are studied in the paper. Implantation of the powder particles into the substrate surface and simultaneous plastic deformation at partial melting improved the mechanical properties of the coatings - tensile strength limit was 650 MPa and adhesion strength was 105 MPa. It was shown that insufficient laser power leads to disruption of the deposition process stability and coating cracking. Surface temperature increase caused by laser heating above 1300 °C resulted in coating melting. The X-ray analysis showed that radiation intensifies the cold spray process and does not cause changes in the austenitic base structure.

  15. High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2014-01-01

    Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

  16. Structural and interfacial analysis of WC92-Co8 coating deposited on titanium alloy by electrospark deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.J.; Qian, Y.Y.; Liu, J

    2004-04-30

    Electrospark deposition (ESD) is a promising process to produce hard and wear-resisting coatings on metallic substrates. In this paper, microstructure and interfacial characteristics of the WC92-Co8 coated-titanium are presented. A metallurgical bonding between the coating and substrate is obtained. The Ti element was found to distribute in WC92-Co8 at the metal pool, as well as the interface by diffusion. Some new phases were produced in the coating layer due to the chemical reaction during the ESD process. Experimental observation and thermodynamic analysis were utilized to study the mechanism of ESD.

  17. Structural and interfacial analysis of WC92 Co8 coating deposited on titanium alloy by electrospark deposition

    Science.gov (United States)

    Wang, R. J.; Qian, Y. Y.; Liu, J.

    2004-04-01

    Electrospark deposition (ESD) is a promising process to produce hard and wear-resisting coatings on metallic substrates. In this paper, microstructure and interfacial characteristics of the WC92-Co8 coated-titanium are presented. A metallurgical bonding between the coating and substrate is obtained. The Ti element was found to distribute in WC92-Co8 at the metal pool, as well as the interface by diffusion. Some new phases were produced in the coating layer due to the chemical reaction during the ESD process. Experimental observation and thermodynamic analysis were utilized to study the mechanism of ESD.

  18. Anodization process produces opaque, reflective coatings on aluminum

    Science.gov (United States)

    1965-01-01

    Opaque, reflective coatings are produced on aluminum articles by an anodizing process wherein the anodizing bath contains an aqueous dispersion of finely divided insoluble inorganic compounds. These particles appear as uniformly distributed occlusions in the anodic deposit on the aluminum.

  19. Raman microscopic studies of PVD deposited hard ceramic coatings

    CERN Document Server

    Constable, C P

    2000-01-01

    GPa were deposited onto SS and HSS substrates. Subsequent Raman measurements found a correlation coefficient of 0.996 between Raman band position and stress (determined via XRD methods). In addition, there was also a similar correlation coefficient observed between hardness and Raman shift (cm sup - sup 1). The application of mechanical stresses on a TiAICrN coating via a stress rig was investigated and tensile and compressive shifts were observed. stresses caused by the scratching process. These shifts were found to be the largest at the edges of scratches. The Raman mapping of 'droplets', a defect inherent to PVD deposition processes, found that higher compressive stresses and large amounts of disorder occurred for coating growth onto droplets. Strategies designed to evaluate the ability of Raman microscopy to monitor the extent of real wear on cutting tools were evaluated. The removal of a coating layer and subsequent detection of a base layer proved successful. This was then expanded to real wear situatio...

  20. Microwave assisted apatite coating deposition on Ti6Al4V implants.

    Science.gov (United States)

    Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B

    2013-10-01

    In this work we report a novel microwave assisted technology to deposit a uniform, ultra-thin apatite coating without any cracks on titanium implants in minutes. This method comprises of conventional biomimetic coating in synergism with microwave irradiation to result in alkaline earth phosphate nucleation. The microwave assisted coating process mainly follows the initial stages of biomimetic coating until the step of the Ca-P nuclei formation. After that, due to microwave irradiation more Ca-P nuclei are formed to cover the whole surface of the implant instead of the growth of deposited Ca-P nuclei to Ca-P globules and coatings. It is interesting to note the doping of Mg(2+) to Ca-P apatite coating can significantly change the properties and performances of as-deposited coatings. The hydrophilicity, physical properties, bioactivity, cell adhesion, and growth capability of as-deposited microwave assisted coatings were investigated. The study shows that this coating technology has great potential in biomedical applications. Additionally, since biomimetic coating can be applied to series of implant materials such as polymer, metals and glass, it is expected this microwave assisted coating technology can also be applied to these materials if they can remains stable at 100 °C, the boiling point of water.

  1. Effects of Y2O3 on the microstructure and wear resistance of cobalt-based alloy coatings deposited by plasma transferred arc process

    Institute of Scientific and Technical Information of China (English)

    HOU Qingyu; HUANG Zhenyi; GAO Jiasheng

    2007-01-01

    Cobalt-based alloys with different Y2O3 contents were deposited on Q235A-carbon steel using plasma transferred arc (PTA) welding machine. The effect of Y2O3 on the microstructure and wear resistance properties of the cobalt-based alloys were investigated using an optical microscope, a scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). It was found that a cobalt-based solid solution with a face-centered cubic crystal structure was presented accompanied by the secondary phase M7C3 with a hexagonal crystal structure in the Y2O3-free cobalt-based alloy coating. Several stacking faults exist in the cobalt-based solid solution. The addition of Y2O3leads to the existence of the Y2O3 phase in the Y2O3-modified coatings. Though stacking fault exists in the Y2O3-modified coatings, its density increases. The addition of Y2O3 can refine the microstructure and can increase the wear resistance properties when its contents are less than or equal to 0.8 wt.%. However, further increase of its contents will lead to the agglomeration of undissolved Y2O3 particles at the γ-Co grain boundary, and will lead to a coarse microstructure and lower wear resistance properties.

  2. The electrochemical deposition of tin-nickel alloys and the corrosion properties of the coating

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Møller, Per

    2005-01-01

    The electrodeposition of tin/nickel (65/35 wt%) is a unique coating process because of the deposition of an intermetallic phase of nickel and tin, which cannot be formed by any pyrometallurgical process. From thermodynamic calculations it can be shown that intermetallic phases can be formed through...... of electrochemical tests, including polarization curves, chronoamperometric studies and tribocorrosion tests have been performed to show the consequence of replacing nickel coatings with tin/nickel coatings....

  3. Ceramic Top Coats of Plasma-Sprayed Thermal Barrier Coatings: Materials, Processes, and Properties

    Science.gov (United States)

    Bakan, Emine; Vaßen, Robert

    2017-08-01

    The ceramic top coat has a major influence on the performance of the thermal barrier coating systems (TBCs). Yttria-partially-stabilized zirconia (YSZ) is the top coat material frequently used, and the major deposition processes of the YSZ top coat are atmospheric plasma spraying and electron beam physical vapor deposition. Recently, also new thermal spray processes such as suspension plasma spraying or plasma spray-physical vapor deposition have been intensively investigated for TBC top coat deposition. These new processes and particularly the different coating microstructures that can be deposited with them will be reviewed in this article. Furthermore, the properties and the intrinsic-extrinsic degradation mechanisms of the YSZ will be discussed. Following the TBC deposition processes and standard YSZ material, alternative ceramic materials such as perovskites and hexaaluminates will be summarized, while properties of pyrochlores with regard to their crystal structure will be discussed more in detail. The merits of the pyrochlores such as good CMAS resistance as well as their weaknesses, e.g., low fracture toughness, processability issues, will be outlined.

  4. Effect of Heat Treatment on Wear Resistance of Nickel Aluminide Coatings Deposited by HVOF and PTA

    Science.gov (United States)

    Benegra, M.; Santana, A. L. B.; Maranho, O.; Pintaude, G.

    2015-08-01

    This study aims to compare the wear resistance of nickel aluminide coatings deposited using plasma transferred arc (PTA) and high-velocity oxygen fuel (HVOF) processes. Wear resistance was measured in rubber wheel abrasion tests. In both deposition processes, the same raw material (nickel aluminide powder) was atomized and deposited on a 316L steel plate substrate. After deposition, specimens were subjected to thermal cycling, aiming solubilization and precipitation. Coatings deposited using PTA developed different microstructures as a result of the incorporation of substrate elements. However, despite the presence of these microstructures, they performed better than coatings processed using HVOF before the heat treatment. After thermal cycling, the superficial hardness after the wear tests for both processes was similar, resulting in similar mass losses.

  5. Protective silicon coating for nanodiamonds using atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lu, J. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004 (China); College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004 (China); Wang, Y.H. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004 (China); College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004 (China); Zang, J.B. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004 (China) and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004 (China)]. E-mail: diamondzjb@163.com; Li, Y.N. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004 (China); College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei 066004 (China)

    2007-01-30

    Ultrathin silicon coating was deposited on nanodiamonds using atomic layer deposition (ALD) from gaseous monosilane (SiH{sub 4}). The coating was performed by sequential reaction of SiH{sub 4} saturated adsorption and in situ decomposition. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to investigate the structural and morphological properties of the coating. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to compare the thermal stability of nanodiamonds before and after silicon coating. The results confirmed that the deposited cubic phase silicon coating was even and continuous. The protective silicon coating could effectively improve the oxidation resistance of nanodiamonds in air flow, which facilitates the applications of nanodiamonds that are commonly hampered by their poor thermal stability.

  6. Plasma Spray-Physical Vapor Deposition (PS-PVD) of Ceramics for Protective Coatings

    Science.gov (United States)

    Harder, Bryan J.; Zhu, Dongming

    2011-01-01

    In order to generate advanced multilayer thermal and environmental protection systems, a new deposition process is needed to bridge the gap between conventional plasma spray, which produces relatively thick coatings on the order of 125-250 microns, and conventional vapor phase processes such as electron beam physical vapor deposition (EB-PVD) which are limited by relatively slow deposition rates, high investment costs, and coating material vapor pressure requirements. The use of Plasma Spray - Physical Vapor Deposition (PS-PVD) processing fills this gap and allows thin (coatings of less than 100 microns to be generated with the flexibility to tailor microstructures by changing processing conditions. Coatings of yttria-stabilized zirconia (YSZ) were applied to NiCrAlY bond coated superalloy substrates using the PS-PVD coater at NASA Glenn Research Center. A design-of-experiments was used to examine the effects of process variables (Ar/He plasma gas ratio, the total plasma gas flow, and the torch current) on chamber pressure and torch power. Coating thickness, phase and microstructure were evaluated for each set of deposition conditions. Low chamber pressures and high power were shown to increase coating thickness and create columnar-like structures. Likewise, high chamber pressures and low power had lower growth rates, but resulted in flatter, more homogeneous layers

  7. Processing and properties of electrodeposited layered surface coatings

    DEFF Research Database (Denmark)

    Horsewell, Andy

    1998-01-01

    clacks and spalls off early on. For thick, non-compliant coatings, much thicker coatings can be formed. Fracture resistance must be considered in relation to both specimen and loading geometries. Since the inherent bending moment causes a maximum tensile stress at the coating surface, the loading......Hard chromium, produced by conventional dir ect curl ent (DC) electrodeposition, cannot be deposited to thicknesses gl enter than about 5 mu m because of the buildup of processing stresses which cause channel cracks in the coating. Much thicker chromium coatings map be produced by depositing...... a layered structure using alternate DC plating and periodic current reversal (PR). Such layering produces a through thickness stepped gradient in residual stresses. Most importantly a bending moment develops in the coating whenever the substrate is compliant. For thin, compliant substrates, the coating...

  8. Bismuth coatings deposited by the pulsed dc sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, M. F.; Olaya, J. J.; Alfonso, J. E., E-mail: jealfonsoo@unal.edu.co [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Ciencia de Materiales y Superficies, Carrera 45 No. 26-85, Edif. Uriel Gutierrez, Bogota D. C. (Colombia)

    2013-08-01

    In this work we present the results obtained from the deposition of nano-structured bismuth coatings through Dc pulsed unbalanced magnetron sputtering. The coatings were grown on two substrates: silicon and AISI steel 316 L. The microstructure of the Bi coatings grown on silicon and the corrosion resistance of the Bi coatings grown on AISI steel were evaluated. The microstructure was evaluated by X-ray diffraction and the corrosion resistance was characterized by means of polarization potentiodynamic and electrochemical impedance spectroscopy. Finally the morphology of the coatings was evaluated through scanning electronic microscopy. The X-ray diffraction analysis indicates that the coatings are polycrystalline; the corrosion resistance tests indicate that the films with better corrosion resistance were deposited at 40 khz. Scanning electron microscopy micrographs show that the coatings are grown as granular form. (Author)

  9. Optimization of electrodeposition processes for tin coatings

    Science.gov (United States)

    Wen, Shixue

    The mechanism of nucleation and growth of tin electrodeposits was investigated. Also the influences of the operating parameters on the morphology, texture, and microstructure as well as the corrosion resistance of tin coatings were studied in order to propose optimum deposition conditions. Tin electrodeposition on glassy carbon and steel from acid sulfate electrolytes proceeds via the 3D (Volmer-Weber) mechanism. On low carbon steel substrates, 3D tin crystallites are initially formed preferentially on step edges, followed by fast deposition of other sites with much smaller and densely packed crystallites of about 150-180 nm in diameter. It was discovered that hydrogen co-evolution and gelatin have a synergy effect contributing to the fast and complete coverage of steel substrate with tin. The cathodic potential oscillation of tin (II) reduction in the tin electrolyte is attributed to the depletion and restoration of tin ions on the cathode surface. It has been found that an increase in current density improves the coverage of the substrate or the covering power. Without agitation, the deposits are powdery at high current densities. In order to obtain smooth and compact coatings, agitation is crucial when the applied current density is well above the limiting value. Tin coatings with two different fibre textures, (100) and (301) were produced by electrodeposition. At a lower current density of 100 A/m 2, (301) fibre was obtained. At the current densities of 100 and up to 400 A/m2, only (100) fibre texture was observed. An increase in current density leads to a decrease in grain size. At the same current density, the grain size of tin coatings increases with increased temperature. The influence of temperature (20, 40, 60 and 80°C) on texture is small. The corrosion resistance of tin coatings increases with a decrease in grain size. The corrosion resistance of tin coatings with (301) fibre was higher than that of the tin coating with (100) fibre texture. The optimum

  10. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  11. A novel electrostatic dry powder coating process for pharmaceutical dosage forms: immediate release coatings for tablets.

    Science.gov (United States)

    Qiao, Mingxi; Zhang, Liqiang; Ma, Yingliang; Zhu, Jesse; Chow, Kwok

    2010-10-01

    An electrostatic dry powder coating process for pharmaceutical solid dosage forms was developed for the first time by electrostatic dry powder coating in a pan coater system. Two immediate release coating compositions with Opadry® AMB and Eudragit® EPO were successfully applied using this process. A liquid plasticizer was sprayed onto the surface of the tablet cores to increase the conductivity of tablet cores to enhance particle deposition, electrical resistivity reduced from greater than 1×10(13)Ωm to less than 1×10(9)Ωm, and to lower the glass transition temperature (T(g)) of the coating polymer for film forming in the pan coater. The application of liquid plasticizer was followed by spraying charged coating particles using an electrostatic charging gun to enhance the uniform deposition on tablet surface. The coating particles were coalesced into a thin film by curing at an acceptable processing temperature as formation was confirmed by SEM micrographs. The results also show that the optimized dry powder coating process produces tablets with smooth surface, good coating uniformity and release profile that are comparable to that of the tablet cores. The data also suggest that this novel electrostatic dry powder coating technique is an alternative to aqueous- or solvent-based coating process for pharmaceutical products. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  12. NiCrSiB Coatings Deposited by Plasma Transferred Arc on Different Steel Substrates

    Science.gov (United States)

    Reinaldo, P. R.; D'Oliveira, A. S. C. M.

    2013-02-01

    Colmonoy 6 (NiCrSiB) is a Ni-based alloy recognized for its superior mechanical properties, attributed to the presence of a dispersion of hard carbides and borides, which is strongly dependent on processing technique. This work gathered microstructure data from the literature and analyzed Colmonoy 6 coatings deposited by plasma transferred arc hardfacing. The aim of the study was to determine the influence of PTA deposition parameters and substrate chemical composition on NiCrSiB coating characteristics. Coatings were characterized in terms of their hardness, dilution, and microstructure, as well as mass loss during abrasive sliding wear tests. The results showed that coating performance is strongly dependent on the chemical composition of the substrate. Carbon steel substrate yielded coatings with greater wear resistance. Processing parameters also alter the performance of coatings, and the lower current and lower travel speed result in reduced mass loss.

  13. Characterisation of the TiO2 coatings deposited by plasma spraying

    Science.gov (United States)

    Benea, M. L.; Benea, L. P.

    2016-02-01

    Plasma spraying of materials such as ceramics and non-metals, which have high melting points, has become a well-established commercial process. Such coatings are increasingly used in aerospace, automobile, textile, medical, printing and electrical industries to impart proprieties such as corrosion resistance, thermal resistance, wear resistance, etc. One of the most important characteristics of thermal barrier coatings is the ability to undergo fast temperature changes without failing, the so called thermal shock resistance. The formation of residual stresses in plasma sprayed ceramic and metallic coatings is a very complex process. Several factors, such as substrate material, substrate thickness, physical properties of both the substrate and the coating material, deposition rate, relative velocity of the plasma torch, etc. determine the final residual stress state of the coating at room temperature. Our objective is to characterize the titanium oxide and aluminium oxide coatings deposited by plasma spraying in structural terms, the resistance to thermal shock and residual stresses.

  14. Chemical vapor deposition of ceramic coatings on metals and ceramic fibers

    Science.gov (United States)

    Nable, Jun Co

    2005-07-01

    The research presented in this study consists of two major parts. The first part is about the development of ceramic coatings on metals by chemical vapor deposition (CVD) and metal-organic chemical vapor deposition (MOCVD). Ceramics such as Al2O3 and Cr2O3, are used as protective coatings for materials used at elevated temperatures (>700°C). These metal oxides either exhibit oxidation resistance or have been used as environmental bond coats. Conventional methods of coating by chemical vapor deposition requires deposition temperatures of >950°C which could damage the substrate material during the coating process. Lower deposition temperatures (400 to 600°C) by MOCVD of these metal oxides were successful on Ni metal substrates. Surface modification such as pre-oxidation and etching were also investigated. In addition, a novel approach for the CVD of TiN on metals was developed. This new approach utilizes ambient pressure conditions which lead to deposition temperatures of 800°C or lower compared to conventional CVD of TiN at 1000°C. Titanium nitride can be used as an abrasive and wear coating on cutting and grinding tools. This nitride can also serve as a diffusion coating in metals. The second major part of this research involves the synthesis of interfacial coatings on ceramic reinforcing fibers for ceramic matrix composites. Aluminum and chromium oxides were deposited onto SiC, and Al2O3-SiO 2 fibers by MOCVD. The effects of the interface coatings on the tensile strength of ceramic fibers are also discussed. New duplex interface coatings consisting of BN or TiN together with Al2O3 or ZrO 2 were also successfully deposited and evaluated on SiC fibers.

  15. Coating Processes for Columbium Alloys

    Science.gov (United States)

    1976-09-01

    by si!; cid ;ng w;th pack cementation. Cu:rently, the modifier layer is deposited by -anual dipping in a slurry. Th’s process is costly and results ;n...A., "Electrophoretic Deposition of Metals, J. Electrochemical Society, Vol. 110, No. 7, p. 843, 1963. 12. Gutierrez , C. P., Mosley, J. R. and

  16. Cold spray deposition of Ti2AlC coatings for improved nuclear fuel cladding

    Science.gov (United States)

    Maier, Benjamin R.; Garcia-Diaz, Brenda L.; Hauch, Benjamin; Olson, Luke C.; Sindelar, Robert L.; Sridharan, Kumar

    2015-11-01

    Coatings of Ti2AlC MAX phase compound have been successfully deposited on Zircaloy-4 (Zry-4) test flats, with the goal of enhancing the accident tolerance of LWR fuel cladding. Low temperature powder spray process, also known as cold spray, has been used to deposit coatings ∼90 μm in thickness using powder particles of accident tolerance to nuclear fuel cladding.

  17. Structure of TiBN coatings deposited onto cemented carbides and sialon tool ceramics

    OpenAIRE

    L.A. Dobrzański; M. Staszuk; J. Konieczny; W. Kwaśny; M. Pawlyta

    2009-01-01

    Purpose: The aim of this paper was investigated structure of sintered carbides WC-Co type and sialon tool ceramics with wear resistance ternary coatings TiBN type deposited by cathodes arc evaporation process (CAE-PVD).Design/methodology/approach: Observation of fracture and topography studied coatings were done by scanning electron microscope. Chemical composition was determine by energy dispersive spectrometry (EDS) method. Thin foils of substrates and coatings by transmission electron micr...

  18. Boron carbide (B4C) coating. Deposition and testing

    Science.gov (United States)

    Azizov, E.; Barsuk, V.; Begrambekov, L.; Buzhinsky, O.; Evsin, A.; Gordeev, A.; Grunin, A.; Klimov, N.; Kurnaev, V.; Mazul, I.; Otroshchenko, V.; Putric, A.; Sadovskiy, Ya.; Shigin, P.; Vergazov, S.; Zakharov, A.

    2015-08-01

    Boron carbide was proposed as a material of in-situ protecting coating for tungsten tiles of ITER divertor. To prove this concept the project including investigation of regimes of plasma deposition of B4C coating on tungsten and tests of boron carbide layer in ITER-like is started recently. The paper contends the first results of the project. The results of B4C coating irradiation by the plasma pulses of QSPU-T plasma accelerator are presented. The new device capable of B4C film deposition on tungsten and testing of the films and materials with ITER-like heat loads and ion- and electron irradiation is described. The results of B4C coating deposition and testing of both tungsten substrate and coating are shown and discussed.

  19. Solid coatings deposited from liquid methyl methacrylate via Plasma Polymerization

    Science.gov (United States)

    Wurlitzer, Lisa; Maus-Friedrichs, Wolfgang; Dahle, Sebastian

    2016-09-01

    The polymerization of methyl methacrylate via plasma discharges is well known today. Usually, plasma-enhanced chemical vapor deposition (PECVD) is used to deposit polymer coatings. Solid coatings are formed out of the liquid phase from methyl methacrylate via dielectric barrier discharge. The formation of the coating proceeds in the gas and the liquid phase. To learn more about the reactions in the two phases, the coatings from MMA monomer will be compared to those from MMA resin. Finally, attenuated total reflection infrared spectroscopy, confocal laser scanning microscopy and X-ray photoelectron spectroscopy are employed to characterize the solid coatings. In conclusion, the plasma enhanced chemical solution deposition is compared to the classical thermal polymerization of MMA.

  20. Comments on process of duplex coatings on aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Samir H.A.; QIAN Han-cheng(钱翰城); XIA Bo-cai(夏伯才); WU Shi-ming(吴仕明)

    2004-01-01

    Despite the great achievements made in improvement of wear resistance properties of aluminum alloys,their applications in heavy surface load-bearing are limited. Single coating is insufficient to produce the desired combination of surface properties. These problems can be solved through the duplex coatings. The aim of the present study is to overview the research advances on processes of duplex coatings on aluminum alloys combined with micro plasma oxidation process and with other modern processes such as physical vapour deposition and plasma assisted chemical vapour deposition and also to evaluate the performance of micro plasma oxidation coatings in improving the load-bearing, friction and wear resistance properties of aluminum alloys in comparison with other coatings. Wherein, a more detailed presentation of the processes and their performances and disadvantages are given as well.

  1. 电火花沉积Ni-Cr合金涂层的组织及性能%Microstructure and Properties of Ni-Cr Alloyed Coating Prepared by Electrospark Deposition Processes

    Institute of Scientific and Technical Information of China (English)

    高玉新; 赵程; 易剑

    2012-01-01

    利用电火花沉积技术,采用自制电极在P20钢基材表面沉积Ni-Cr合金涂层,研究了沉积层的组织特征、显微硬度分布及耐磨、耐蚀性能.结果表明:通过优化沉积工艺参数可以获得厚度高达430μm的沉积层.电火花沉积层与基体的结合界面属于非均匀混合互熔结晶型界面,沉积层与基体呈现良好的冶金结合;涂层中下部组织为细小的枝晶组织,而上部组织为纳米晶结构.沉积层的硬度呈梯度分布,涂层外层硬度值最高.涂层的耐磨、耐蚀性能比基体有较大提高,涂层上部超细的纳米晶结构是其耐磨性能及耐蚀性能提高的主要因素.%The Ni-Cr alloyed coating was produced on the surface of P20 steel plate with self-made electrode by electro-spark deposition (ESD) technique. The microstructures and properties of the coating were investigated. The results show that ESD process can produce big-thickness coating with proper process parameters, and the thickness is about 430μm. The coating is well bonded to the matrix and the interface between the coating and the substrate is presented as non-uniformly mixed mu-tuai melting crystallization. The superfine dendritic structure prevails in the middle and bottom of the coating and nano-structured grains in the upper coating. The hardness of the coating shows gradient distribution from the surface reached the largest to the substrate reduced sequentially. Nano-structured particles of the upper coating are the main factors leading to high hardness as well as corrosion and wear resistance of the coating.

  2. Adherent apatite coating on titanium substrate using chemical deposition.

    Science.gov (United States)

    Rohanizadeh, R; LeGeros, R Z; Harsono, M; Bendavid, A

    2005-03-15

    Plasma-sprayed "HA" coatings on commercial orthopedic and dental implants consist of mixtures of calcium phosphate phases, predominantly a crystalline calcium phosphate phase, hydroxyapatite (HA) and an amorphous calcium phosphate (ACP) with varying HA/ACP ratios. Alternatives to the plasma-spray method are being explored because of some of its disadvantages. The purpose of this study was to deposit an adherent apatite coating on titanium substrate using a two-step method. First, titanium substrates were immersed in acidic solution of calcium phosphate resulting in the deposition of a monetite (CaHPO4) coating. Second, the monetite crystals were transformed to apatite by hydrolysis in NaOH solution. Composition and morphology of the initial and final coatings were identified using X-ray diffraction (XRD), Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (EDS). The final coating was porous and the apatite crystals were agglomerated and followed the outline of the large monetite crystals. EDS revealed the presence of calcium and phosphorous elements on the titanium substrate after removing the coating using tensile or scratching tests. The average tensile bond of the coating was 5.2 MPa and cohesion failures were observed more frequently than adhesion failures. The coating adhesion measured using scratch test with a 200-microm-radius stylus was 13.1N. Images from the scratch tracks demonstrated that the coating materials were squashed without fracturing inside and/or at the border of the tracks until the failure point of the coating. In conclusion, this study showed the potential of a chemical deposition method for depositing a coating consisting of either monetite or apatite. This method has the advantage of producing a coating with homogenous composition on even implants of complex geometry or porosity. This method involves low temperatures and, therefore, can allow the incorporation of growth factors or biogenic molecules.

  3. Characterization of Environmental Stability of Pulsed Laser Deposited Oxide Ceramic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS, THADM

    2004-03-02

    A systematic investigation of candidate hydrogen permeation materials applied to a substrate using Pulsed Laser Deposition has been performed. The investigation focused on application of leading permeation-resistant materials types (oxide, carbides, and metals) on a stainless steel substrate. and evaluation of the stability of the applied coatings. Type 304L stainless steel substrates were coated with aluminum oxide, chromium oxide, and aluminum. Characterization of the coating-substrate system adhesion was performed using scratch adhesion testing and microindentation. Coating stability and environmental susceptibility were evaluated for two conditions-air at 350 degrees Celsius and Ar-H2 at 350 degrees Celsius for up to 100 hours. Results from this study have shown the pulsed laser deposition process to be an extremely versatile technology that is capable of producing a sound coating/substrate system for a wide variety of coating materials.

  4. Interface behavior study of WC92-Co8 coating produced by electrospark deposition

    Institute of Scientific and Technical Information of China (English)

    汪瑞军; 钱乙余; 刘军

    2004-01-01

    ESD (electrospark deposition) is a promising process to produce hard and wear-resisting coatings on metallic substrates. In this paper microstructure and interfacial characteristics of the WC92-Co8 coated on titanium and carbon steel are presented. A metallurgical bonding between the coating and substrate is obtained. The Ti element was found to distribute in WC92-Co8 at the metal pool, as well as the interface by diffusion. Some new phases were produced in the coating layer due to the chemical reaction during the ESD process. Experimental observation and thermodynamic analysis were utilized to study the mechanism of ESD.

  5. Adding Processes of Silver Solution and the Deposit Process of Silver Coating during Reduction Preparation of Silver-Coated Copper Powders%还原法制备银包铜粉主盐添加工艺及镀层沉积过程研究

    Institute of Scientific and Technical Information of China (English)

    赵少凡; 夏志东; 周虎; 刘小黑

    2012-01-01

    The silver-coated copper powders were prepared by a reduction method, using glucose as the reductant. The different adding processes of silver-ammonia solution varied the micro-morphology and appearance color of the powders. The coated powders were characterized by SEM and EDS. The silver contents of different adding processes were calculated by titration. Thus the optimal adding process was determined. Meanwhile, the silver coating deposit process was analyzed by observation of the powders taken out from the solution at different stages during silver plating.%用葡萄糖作为还原剂制备银包铜粉.在还原法镀银过程中,主盐溶液以不同的工艺添加可得到不同微观形貌和表观颜色的银包铜粉,用扫描电镜、能谱仪对银包铜粉进行表征,并用滴定法计算不同添加工艺制备的银包铜粉的含银量,确定了较优的主盐添加工艺;同时,通过在施镀过程中阶段性取粉观察,对银包铜粉镀层的沉积过程进行了分析.

  6. Structure And Properties Of PVD Coatings Deposited On Cermets

    Directory of Open Access Journals (Sweden)

    Żukowska L.

    2015-06-01

    Full Text Available The main aim of the research is the investigation of the structure and properties of single-layer and gradient coatings of the type (Ti,AlN and Ti(C,N deposited by physical vapour deposition technology (PVD on the cermets substrate.

  7. Boron coating on boron nitride coated nuclear fuels by chemical vapor deposition

    Science.gov (United States)

    Durmazuçar, Hasan H.; Gündüz, Güngör

    2000-12-01

    Uranium dioxide-only and uranium dioxide-gadolinium oxide (5% and 10%) ceramic nuclear fuel pellets which were already coated with boron nitride were coated with thin boron layer by chemical vapor deposition to increase the burn-up efficiency of the fuel during reactor operation. Coating was accomplished from the reaction of boron trichloride with hydrogen at 1250 K in a tube furnace, and then sintering at 1400 and 1525 K. The deposited boron was identified by infrared spectrum. The morphology of the coating was studied by using scanning electron microscope. The plate, grainy and string (fiber)-like boron structures were observed.

  8. Atomic layer deposition (ALD) as a coating tool for reinforcing fibers.

    Science.gov (United States)

    Roy, A K; Baumann, W; König, I; Baumann, G; Schulze, S; Hietschold, M; Mäder, T; Nestler, D J; Wielage, B; Goedel, W A

    2010-03-01

    Layers of alumina were deposited on to bundled carbon fibers in an atomic layer deposition (ALD) process via sequential exposure to vapors of aluminium chloride and water, respectively. Scanning electron microscopic (SEM) images of the coated fibers revealed that each individual fiber within a bundle was coated evenly and separately, fibers are not bridged by the coating. SEM and transmission electron microscopic (TEM) images indicate that the coating was uniform and conformal with good adhesion to the fiber surface. Average deposition rate, measured from SEM images, was 0.06 nm per cycle at 500 °C. SEM also revealed that at deposition temperatures of 500 °C few of the fibers were damaged. At temperatures of 300 °C, no damaged fibers were observed, the average deposition rate decreased down to 0.033 nm per cycle. Oxidation resistance of the alumina-coated fibers was characterized by thermogravimetric analysis (TGA). The alumina coating improved oxidation resistance of the carbon fiber significantly. Oxidation onset temperature was 600 °C for fibers coated with a 45 nm thick alumina. Uncoated fibers, on the other hand, started to oxidize at temperatures as low as 250 °C.

  9. Deposition of copper coatings in a magnetron with liquid target

    Energy Technology Data Exchange (ETDEWEB)

    Tumarkin, A. V., E-mail: sanyahrustal@mail.ru; Kaziev, A. V.; Kolodko, D. V.; Pisarev, A. A.; Kharkov, M. M.; Khodachenko, G. V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2015-12-15

    Copper coatings were deposited on monocrystalline Si substrates using a magnetron discharge with a liquid cathode in the metal vapour plasma. During the deposition, the bias voltage in the range from 0 V to–400 V was applied to the substrate. The prepared films were investigated by a scanning electron microscope, and their adhesive properties were studied using a scratch tester. It was demonstrated that the adhesion of the deposited films strongly depends on the bias voltage and varies in a wide range.

  10. Modified drug release using atmospheric pressure plasma deposited siloxane coatings

    Science.gov (United States)

    Dowling, D. P.; Maher, S.; Law, V. J.; Ardhaoui, M.; Stallard, C.; Keenan, A.

    2016-09-01

    This pilot study evaluates the potential of atmospheric plasma polymerised coatings to modify the rate of drug release from polymeric substrates. The antibiotic rifampicin was deposited in a prototype multi-layer drug delivery system, consisting of a nebulized layer of active drug between a base layer of TEOS deposited on a plastic substrate (polystyrene) and an overlying layer of plasma polymerised PDMS. The polymerised TEOS and PDMS layers were deposited using a helium atmospheric plasma jet system. Elution of rifampicin was measured using UV-VIS spectroscopy, in addition to a antimicrobial well diffusion assay with an established indicator organism. The multi-layered plasma deposited coatings significantly extended the duration of release of the rifampicin from 24 h for the uncoated polymer to 144 h for the coated polymer.

  11. Simulation on Stress Accumulation during the Path-by-path Deposition Process of Thermal Barrier Coating by Plasma Spraying%等离子喷涂热障涂层逐道沉积累积应力的模拟

    Institute of Scientific and Technical Information of China (English)

    田甜; 郑振环; 李强

    2012-01-01

    运用ANSYS12.0软件,对等离子喷涂热障涂层逐道沉积过程中的累积应力进行了有限元模拟.结果表明,涂层制备过程中,已喷涂层的温度随喷枪移动呈周期性大幅波动,这种快速热冲击使得涂层中产生了相应的应力波动.涂层喷涂结束并冷却至室温后,边缘存在应力集中,陶瓷层与粘结层的界面边缘处最大切向拉应力为122 MPa.涂层各界面中部应力值呈波浪状周期性浮动,X方向应力是主要的应力形式.%Finite element simulatin on stress accumulation during the path-by-path deposilin process of thermal barrier coating by plasma spraying was performed by FEM software ANSYS12.0. During the spraying process, the temperature of the deposited coating fluctuates with the movement of the spraying gun periodically within a wide range. This rapid thermal shock will cause a corresponding stress fluctuation. After the coating being cooled to the room temperture, concentrated stress appeared at the edge of the coating, the maximum shear tensile stress existed at the edge of the interface between the ceramic layer and the bonding layer is 122 MPa. Stress at the middle of the interfaces of the coating fluctuates periodically like a wave and stress in the X direction is the major stress.

  12. Piezoelectric film electro-deposition for optical fiber sensor with ZnO coating

    Institute of Scientific and Technical Information of China (English)

    Li Zhou; Ping Gu; Ya Zhou

    2008-01-01

    The piezoelectric film electro-deposition for optical fiber sensor with ZnO coating is studied. The zinc oxide plating film is made on the copper surface directly by cathodic electro-deposition in the Zn(NO3)2 single salt aqueous solution systems. The influences of main experimental conditions on the properties of ZnO thin film in the electro-deposition processes are analyzed and a stable, practical and economic technique is obtained.

  13. Chemical vapor deposited fiber coatings and chemical vapor infiltrated ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Kmetz, M.A.

    1992-01-01

    Conventional Chemical Vapor Deposition (CVD) and Organometallic Chemical Vapor Deposition (MOCVD) were employed to deposit a series of interfacial coatings on SiC and carbon yarn. Molybdenum, tungsten and chromium hexacarbonyls were utilized as precursors in a low temperature (350[degrees]C) MOCVD process to coat SiC yarn with Mo, W and Cr oxycarbides. Annealing studies performed on the MoOC and WOC coated SiC yarns in N[sub 2] to 1,000[degrees]C establish that further decomposition of the oxycarbides occurred, culminating in the formation of the metals. These metals were then found to react with Si to form Mo and W disilicide coatings. In the Cr system, heating in N[sub 2] above 800[degrees]C resulted in the formation of a mixture of carbides and oxides. Convention CVD was also employed to coat SiC and carbon yarn with C, Bn and a new interface designated BC (a carbon-boron alloy). The coated tows were then infiltrated with SiC, TiO[sub 2], SiO[sub 2] and B[sub 4]C by a chemical vapor infiltration process. The B-C coatings were found to provide advantageous interfacial properties over carbon and BN coatings in several different composite systems. The effectiveness of these different coatings to act as a chemically inert barrier layer and their relationship to the degree of interfacial debonding on the mechanical properties of the composites were examined. The effects of thermal stability and strength of the coated fibers and composites were also determined for several difference atmospheres. In addition, a new method for determining the tensile strength of the as-received and coated yarns was also developed. The coated fibers and composites were further characterized by AES, SEM, XPS, IR and X-ray diffraction analysis.

  14. On the control of deposition process for enhanced mechanical properties of nc-TiC/a-C:H coatings with DC magnetron sputtering at low or high ion flux

    NARCIS (Netherlands)

    Souček, Pavel; Schmidtová, Tereza; Zábranský, Lukáš; Buršíková, Vilma; Vašina, Petr; Caha, Ondřej; Buršík, Jiří; Peřina, Vratislav; Mikšová, Romana; Pei, Y.T.; De Hosson, J.T.M.

    2014-01-01

    Nanocomposite coatings consisting of nanocrystallites embedded in an amorphous matrix can be tailored to exhibit unusual combination of properties such as high hardness and modulus combined with low friction and wear. The properties of the coatings are governed by parameters of the deposition plasma

  15. Thermal conductivity of titanium aluminum silicon nitride coatings deposited by lateral rotating cathode arc

    Energy Technology Data Exchange (ETDEWEB)

    Samani, M.K., E-mail: majid1@e.ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Surface Technology Group, Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); CINTRA-CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553 (Singapore); Ding, X.Z. [Surface Technology Group, Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Amini, S. [School of Materials Science and Engineering. Nanyang Technological University, 50 Nanyang Avenue, Singapore (Singapore); Khosravian, N.; Cheong, J.Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Chen, G. [BC Photonics Technological Company, 5255 Woodwards Rd., Richmond, BC V7E 1G9 (Canada); Tay, B.K. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); CINTRA-CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553 (Singapore)

    2013-06-30

    A series of physical vapour deposition titanium aluminum silicon nitride nanocomposite coating with a different (Al + Si)/Ti atomic ratio, with a thickness of around 2.5 μm were deposited on stainless steel substrate by a lateral rotating cathode arc process in a flowing nitrogen atmosphere. The composition and microstructure of the as-deposited coatings were analyzed by energy dispersive X-ray spectroscopy, and X-ray diffraction, and cross-sectional scanning electron microscopy observation. The titanium nitride (TiN) coating shows a clear columnar structure with a predominant (111) preferential orientation. With the incorporation of Al and Si, the crystallite size in the coatings decreased gradually, and the columnar structure and (111) preferred orientation disappeared. Thermal conductivity of the as-deposited coating samples at room temperature was measured by using pulsed photothermal reflectance technique. Thermal conductivity of the pure TiN coating is about 11.9 W/mK. With increasing the (Al + Si)/Ti atomic ratio, the coatings' thermal conductivity decreased monotonously. This reduction of thermal conductivity could be ascribed to the variation of coatings' microstructure, including the decrease of grain size and the resultant increase of grain boundaries, the disruption of columnar structure, and the reduced preferential orientation. - Highlights: • A series of titanium aluminum silicon nitride with different (Al + Si)/Ti atomic ratio were deposited on Fe304. • The composition and microstructure of the as-deposited coatings were analyzed. • Thermal conductivity of the samples was measured by pulsed photothermal reflectance. • With increasing the (Al + Si)/Ti atomic ratio, thermal conductivity decreased. • Reduction of thermal conductivity is ascribed to the variation of its microstructure.

  16. Process engineering of ceramic composite coatings for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Kim, H.; Chen, M.; Yang, Q.; Troczynski, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Metals and Materials Engineering

    2003-07-01

    Researchers at UBCeram at the Department of Metals and Materials Engineering at the University of British Columbia have developed a technology to chemically bond composite sol-gel (CB-CSG) coating onto metallic surfaces of complex or concave shapes. The process has been optimized for electrically resistive coatings and corrosion-resistant coatings. The CSG is sprayed onto metallic surfaces and is heat-treated at 300 degrees C to partially dehydrate the hydroxides. The CSG film is then chemically bonded through reaction of active alumina with metal phosphates, such as aluminium phosphate. A new chromate-free process is being developed to address the issue of coatings porosity. The electrodeposition technique involves polymer particles mixed with suspended fine alumina particles which are co-deposited by electrophoretic means or by electrocoagulation. The composite e-coatings have excellent mechanical properties and are being considered as a protective coating for various components of fuel cell systems. 9 refs., 7 figs.

  17. Tribological Performance of MoS2-based Coatings after Deposition and Storage in Humid Air

    Institute of Scientific and Technical Information of China (English)

    JINGYang; LUOJian-bin; PANGSi-qin

    2004-01-01

    MoS2-based composite coatings were deposited with the nano-compound unbalanced plasma plating technique the effects of processing parameters and working enwironments on the tribological properties of the coatings were examined by the drilling experiuments and XPS.the distances between substrate and Ti larget, Ti content and deposition pressure were varied in order to determine the optimun conditions for producing lubricious,long-lasting MoS2-based coatings,IT is found that the tribological performance of Tin-MoS2 roating decreases rqapidly in humid air but the humid resistant property of Tin-MoS2/Ti coating improves evidently it is indicated that the humid-resistantance property and the abrasion durability of MoS2-based coatings can be enhanced markedly by adding Ti with a certain contents.

  18. Nanoparticle dispersion-strengthened coatings and electrode materials for electrospark deposition

    Energy Technology Data Exchange (ETDEWEB)

    Levashov, E.A. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation)]. E-mail: levashov@shs.misis.ru; Vakaev, P.V. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Zamulaeva, E.I. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Kudryashov, A.E. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Pogozhev, Yu.S. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Shtansky, D.V. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Voevodin, A.A. [Air Force Research Laboratory, 2941 Hobson Way, Wright Patterson AFB, OH 45433 (United States); Sanz, A. [SKF Engineering and Research Centre, P.O. Box 2350 Kelvinbaan 16, 3430 DT Nieuwegein, 3439 MT Nieuwegein (Netherlands)

    2006-11-23

    Advanced electrode compositions were developed using self-propagating high-temperature synthesis (SHS). Electrospark deposition (ESD) was applied to produce tribological coatings which were disperse-strengthened by incorporation of nanosized particles. Nanostructured electrodes of cemented carbides were produced using powder metallurgy technologies. They allow increasing the coatings density, thickness, hardness, Young's modulus and wear resistance. Positive effects of the nanostructure of electrodes on the deposition process and structure and properties of the coatings are discussed. In that case the tungsten carbide phases become predominant in the coatings. A mechanism of the dissolution reaction of WC with Ni at the contact surface of electrode was proposed. It was shown that the formation of the coating structure starts on the electrode and is accomplished on the substrate.

  19. Characterization of the chemically deposited hydroxyapatite coating on a titanium substrate.

    Science.gov (United States)

    Zavgorodniy, Alexander V; Borrero-López, Oscar; Hoffman, Mark; Legeros, Racquel Z; Rohanizadeh, Ramin

    2011-01-01

    Bioactive hydroxyapatite (HA) coating on titanium (Ti) implant can be used as a drug delivery device. A controlled release of drug around the implant requires the incorporation of drug into the coating material during the coating process. HA coating was prepared using a two-step procedure in conditions suitable for simultaneous incorporation of the protein-based drug into the coating material. Monetite coating was deposited on Ti substrate in acidic condition followed by the transformation of the monetite coating to HA. X-ray diffraction (XRD) confirmed the formation of the monetite phase at the first step of the coating preparation, which was transformed into HA at the second step. Fourier transform infrared spectroscopy demonstrated typical bands of a crystallized carbonated HA with A- and B-type substitution, which was confirmed by the XRD refinement of the structural parameters. Scanning electron microscope was used to observe the morphology of monetite and HA coatings. Adhesion of the coatings was measured using a scratch tester. The critical shearing stress was found to be 84.20 ± 1.27 MPa for the monetite coating, and 44.40 ± 2.39 MPa for the HA coating.

  20. Plasma Assisted Chemical Vapour Deposition – Technological Design Of Functional Coatings

    Directory of Open Access Journals (Sweden)

    Januś M.

    2015-06-01

    Full Text Available Plasma Assisted Chemical Vapour Deposition (PA CVD method allows to deposit of homogeneous, well-adhesive coatings at lower temperature on different substrates. Plasmochemical treatment significantly impacts on physicochemical parameters of modified surfaces. In this study we present the overview of the possibilities of plasma processes for the deposition of diamond-like carbon coatings doped Si and/or N atoms on the Ti Grade2, aluminum-zinc alloy and polyetherketone substrate. Depending on the type of modified substrate had improved the corrosion properties including biocompatibility of titanium surface, increase of surface hardness with deposition of good adhesion and fine-grained coatings (in the case of Al-Zn alloy and improving of the wear resistance (in the case of PEEK substrate.

  1. Investigation of thin titanium carbonitride coatings deposited onto stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Timothy; Lin, Jia-Ming [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Pirolli, Laurent; Coquilleau, Laurent; Luharuka, Rajesh [Schlumberger Technology Corporation, 150 Gillingham Lane, MD-3, Sugarland, TX 77478 (United States); Teplyakov, Andrew V., E-mail: andrewt@udel.edu [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States)

    2012-11-01

    Titanium carbonitride (TiCN) coatings are commonly used in a variety of applications, from microelectronics to high-performance cutting tools. The TiCN coatings grown by chemical vapor deposition are especially attractive because this technique provides a very high degree of control during the procedure. A gas-phase deposition utilizing an organometallic precursor molecule, tetrakis-dimethylamino-titanium was used to grow thin TiCN coatings onto 4140 series steel prepared and cleaned in vacuum. A highly controlled conformal filling was achieved by the deposition performed onto a sputter-cleaned steel surface held at 600 K. The film of the overall Ti:C:N composition of 1:1:1 was produced, as demonstrated by Auger electron spectroscopy. In air, these coatings are oxidized but maintain their uniformity, as demonstrated by time-of-flight secondary ion mass spectrometry. The chemical state of the elements in the coatings was investigated by the X-ray photoelectron spectroscopy and the morphology of the films produced was investigated by atomic force microscopy. Finally, the initial mechanical testing of the films was performed by comparing Young's modulus to that of the underlying steel. - Highlights: Black-Right-Pointing-Pointer TiCN film was deposited by chemical vapor deposition onto a steel substrate. Black-Right-Pointing-Pointer The film is comprised of Ti, C, and N and is partially oxidized. Black-Right-Pointing-Pointer The depth-profiling studies confirmed that the film is uniform in thickness. Black-Right-Pointing-Pointer Microscopy investigation showed a sharp interface between the coating and substrate. Black-Right-Pointing-Pointer The topography of coated and uncoated samples is very different.

  2. Automatic and robust deposition process control to grow hard ncTiC/a-C:H coatings using industrial magnetron sputtering devices and tribological analysis of the titanium-carbon coatings

    NARCIS (Netherlands)

    Žemlička, Radek; Jílek, Mojmír; Vogl, Petr; Pei, Yutao; Souček, Pavel; Buršíková, Vilma; Vašina, Petr

    2015-01-01

    nc-TiC/a-C:H coatings consist of TiC crystallites embedded in an amorphous hydrogenated carbon matrix. Depending mainly on the chemical composition, the properties of these coatings can be tailored from hard coatings, with hardness of greater than 35 GPa to tribological coatings, with coefficients o

  3. Application of design of experiment on electrophoretic deposition of glass-ceramic coating materials from an aqueous bath

    Indian Academy of Sciences (India)

    Someswar Datta

    2000-04-01

    A process for application of abrasion- or corrosion-resistant glass-ceramic coating materials on metal substrate by electrophoretic deposition technique in an aqueous medium has been described. The effects of various process parameters, e.g. coating material concentration, time of deposition, applied current, pH of the suspension and concentration of the polymeric dispersant on the deposition efficiency have been studied. The process has been studied using a 23-factorial design technique of three independent variables; i.e. coating material concentration, applied current, and the time taken to achieve the best combination. The regression equation obtained explains the experimental results satisfactorily.

  4. Nanostructured yttria stabilized zirconia coatings deposited by air plasma spraying

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong; LI Fei; HE Bo; WANG Jun; SUN Bao-de

    2007-01-01

    Nanostructured yttria partially stabilized zirconia coatings were deposited by air plasma spraying with reconstituted nanosized powder. The microstructures and phase compositions of the powder and the as-sprayed nanostructured coatings were characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results demonstrate that the microstructure of as-sprayed nanostructured zirconia coating exhibits a unique tri-modal distribution including the initial nanostructure of the powder, equiaxed grains and columnar grains. Air plasma sprayed nanostructured zirconia coatings consist of only the nontransformable tetragonal phase, though the reconstituted nanostructured powder shows the presence of the monoclinic, the tetragonal and the cubic phases. The mean grain size of the coating is about 42 nm.

  5. Collimated Magnetron Sputter Deposition for Mirror Coatings

    DEFF Research Database (Denmark)

    Vickery, A.; Cooper-Jensen, Carsten P.; Christensen, Finn Erland

    2008-01-01

    At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence that a collimat......At the Danish National Space Center (DNSC), a planar magnetron sputtering chamber has been established as a research and production coating facility for curved X-ray mirrors for hard X-ray optics for astronomical X-ray telescopes. In the following, we present experimental evidence...... that a collimation of the sputtered particles is an efficient way to suppress the interfacial roughness of the produced multilayer. We present two different types of collimation optimized for the production of low roughness curved mirrors and flat mirrors, respectively....

  6. Process and apparatus for producing coated particles

    NARCIS (Netherlands)

    Van Ommen, J.R.; Ellis, N.; Yurteri, C.; Marijnissen, J.C.M.

    2010-01-01

    The invention is directed to a process and apparatus for preparing coated particles, in particular a process for preparing particles that are coated with small particles using electrospraying. The coated particles produced according to the present invention find use for instance as catalysts or as

  7. Degradation of Thermal Barrier Coatings from Deposits and Its Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Nitin Padture

    2011-12-31

    Ceramic thermal barrier coatings (TBCs) used in gas-turbine engines afford higher operating temperatures, resulting in enhanced efficiencies and performance. However, in the case of syngas-fired engines, fly ash particulate impurities that may be present in syngas can melt on the hotter TBC surfaces and form glassy deposits. These deposits can penetrate the TBCs leading to their failure. In experiments using lignite fly ash to simulate these conditions we show that conventional TBCs of composition 93wt% ZrO{sub 2} + 7wt% Y{sub 2}O{sub 3} (7YSZ) fabricated using the air plasma spray (APS) process are completely destroyed by the molten fly ash. The molten fly ash is found to penetrate the full thickness of the TBC. The mechanisms by which this occurs appear to be similar to those observed in degradation of 7YSZ TBCs by molten calcium-magnesium-aluminosilicate (CMAS) sand and by molten volcanic ash in aircraft engines. In contrast, APS TBCs of Gd{sub 2Zr{sub 2}O{sub 7} composition are highly resistant to attack by molten lignite fly ash under identical conditions, where the molten ash penetrates ~25% of TBC thickness. This damage mitigation appears to be due to the formation of an impervious, stable crystalline layer at the fly ash/Gd{sub 2}Zr{sub 2}O{sub 7} TBC interface arresting the penetrating moltenfly- ash front. Additionally, these TBCs were tested using a rig with thermal gradient and simultaneous accumulation of ash. Modeling using an established mechanics model has been performed to illustrate the modes of delamination, as well as further opportunities to optimize coating microstructure. Transfer of the technology was developed in this program to all interested parties.

  8. Interface control of atomic layer deposited oxide coatings by filtered cathodic arc deposited sublayers for improved corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Härkönen, Emma, E-mail: emma.harkonen@helsinki.fi [Laboratory of Inorganic Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland); Tervakangas, Sanna; Kolehmainen, Jukka [DIARC-Technology Inc., Espoo (Finland); Díaz, Belén; Światowska, Jolanta; Maurice, Vincent; Seyeux, Antoine; Marcus, Philippe [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7075) – Chimie ParisTech (ENSCP), F-75005 Paris (France); Fenker, Martin [FEM Research Institute, Precious Metals and Metals Chemistry, D-73525 Schwäbisch Gmünd (Germany); Tóth, Lajos; Radnóczi, György [Research Centre for Natural Sciences HAS, (MTA TKK), Budapest (Hungary); Ritala, Mikko [Laboratory of Inorganic Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland)

    2014-10-15

    Sublayers grown with filtered cathodic arc deposition (FCAD) were added under atomic layer deposited (ALD) oxide coatings for interface control and improved corrosion protection of low alloy steel. The FCAD sublayer was either Ta:O or Cr:O–Ta:O nanolaminate, and the ALD layer was Al{sub 2}O{sub 3}–Ta{sub 2}O{sub 5} nanolaminate, Al{sub x}Ta{sub y}O{sub z} mixture or graded mixture. The total thicknesses of the FCAD/ALD duplex coatings were between 65 and 120 nm. Thorough analysis of the coatings was conducted to gain insight into the influence of the FCAD sublayer on the overall coating performance. Similar characteristics as with single FCAD and ALD coatings on steel were found in the morphology and composition of the duplex coatings. However, the FCAD process allowed better control of the interface with the steel by reducing the native oxide and preventing its regrowth during the initial stages of the ALD process. Residual hydrocarbon impurities were buried in the interface between the FCAD layer and steel. This enabled growth of ALD layers with improved electrochemical sealing properties, inhibiting the development of localized corrosion by pitting during immersion in acidic NaCl and enhancing durability in neutral salt spray testing. - Highlights: • Corrosion protection properties of ALD coatings were improved by FCAD sublayers. • The FCAD sublayer enabled control of the coating-substrate interface. • The duplex coatings offered improved sealing properties and durability in NSS. • The protective properties were maintained during immersion in a corrosive solution. • The improvements were due to a more ideal ALD growth on the homogeneous FCAD oxide.

  9. A review of hydroxyapatite-based coating techniques: Sol-gel and electrochemical depositions on biocompatible metals.

    Science.gov (United States)

    Asri, R I M; Harun, W S W; Hassan, M A; Ghani, S A C; Buyong, Z

    2016-04-01

    New promising techniques for depositing biocompatible hydroxyapatite-based coatings on biocompatible metal substrates for biomedical applications have continuously been exploited for more than two decades. Currently, various experimental deposition processes have been employed. In this review, the two most frequently used deposition processes will be discussed: a sol-gel dip coating and an electrochemical deposition. This study deliberates the surface morphologies and chemical composition, mechanical performance and biological responses of sol-gel dip coating as well as the electrochemical deposition for two different sample conditions, with and without coating. The review shows that sol-gel dip coatings and electrochemical deposition were able to obtain the uniform and homogeneous coating thickness and high adherent biocompatible coatings even in complex shapes. It has been accepted that both coating techniques improve bone strength and initial osseointegration rate. The main advantages and limitations of those techniques of hydroxyapatite-based coatings are presented. Furthermore, the most significant challenges and critical issues are also highlighted.

  10. A New Coating Process for Production of Coated Magnesium Powders

    Science.gov (United States)

    2008-04-16

    TGA data for magnesium hydroxide content. TGA analysis of the as-coated powders is a reproducible and accurate method for the determination of... TGA analysis of the as-coated powder, there is approximately 3wt% magnesium hydroxide present in the material due to the process variation compared...11: Magnesium hydroxide content as measured by TGA analysis for the 1-lb batches of as-coated ground powder Figure 12: Nitrometer analysis of

  11. CMAS Interactions with Advanced Environmental Barrier Coatings Deposited via Plasma Spray- Physical Vapor Deposition

    Science.gov (United States)

    Harder, B. J.; Wiesner, V. L.; Zhu, D.; Johnson, N. S.

    2017-01-01

    Materials for advanced turbine engines are expected to have temperature capabilities in the range of 1370-1500C. At these temperatures the ingestion of sand and dust particulate can result in the formation of corrosive glass deposits referred to as CMAS. The presence of this glass can both thermomechanically and thermochemically significantly degrade protective coatings on metallic and ceramic components. Plasma Spray- Physical Vapor Deposition (PS-PVD) was used to deposit advanced environmental barrier coating (EBC) systems for investigation on their interaction with CMAS compositions. Coatings were exposed to CMAS and furnace tested in air from 1 to 50 hours at temperatures ranging from 1200-1500C. Coating composition and crystal structure were tracked with X-ray diffraction and microstructure with electron microscopy.

  12. Electrophoretic deposition of hydroxyapatite-CaSiO3-chitosan composite coatings.

    Science.gov (United States)

    Pang, Xin; Casagrande, Travis; Zhitomirsky, Igor

    2009-02-15

    Electrophoretic deposition (EPD) method has been developed for the fabrication of hydroxyapatite (HA)-CaSiO(3) (CS)-chitosan composite coatings for biomedical applications. The use of chitosan enabled the co-deposition of HA and CS particles and offered the advantage of room temperature processing of composite materials. The coating composition was varied by the variation of HA and CS concentrations in the chitosan solutions. Cathodic deposits were obtained as HA-CS-chitosan monolayers, HA-chitosan/chitosan multilayers or functionally graded materials (FGM) containing HA-chitosan and CS-chitosan layers of different composition. The thickness of the individual layers was varied in the range of 0.1-20 microm. The deposition yield was studied at different experimental conditions and compared with the results of modeling. It was shown that the moving boundary model for the two component system can explain the non-linear increase in the deposition yield with increasing HA concentration in chitosan solutions. The obtained coatings were studied by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and scanning electron microscopy (SEM). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies showed that these coatings provided corrosion protection of stainless steel substrates in Ringer's physiological solution. The deposition mechanism and kinetics of deposition have been discussed.

  13. AC electrophoretic deposition of organic-inorganic composite coatings.

    Science.gov (United States)

    Yoshioka, T; Chávez-Valdez, A; Roether, J A; Schubert, D W; Boccaccini, A R

    2013-02-15

    Alternating current electrophoretic deposition (AC-EPD) of polyacrylic acid (PAA)-titanium oxide (TiO(2)) nanoparticle composites on stainless steel electrodes was investigated in basic aqueous solution. AC square wave with duty cycle of 80% was applied at a frequency of 1 kHz. FTIR-ATR spectra showed that both AC and direct current (DC) EPD successfully deposited PAA-TiO(2) composites. The deposition rate using AC-EPD was lower than that obtained in direct current DC-EPD. However, the microstructure and surface morphology of the deposited composite coatings were different depending on the type of electric field applied. AC-EPD applied for not more than 5 min led to smooth films without bubble formation, while DC-EPD for 1 min or more showed deposits with microstructural defects possibly as result of water electrolysis. AC-EPD was thus for the first time demonstrated to be a suitable technique to deposit organic-inorganic composite coatings from aqueous suspensions, showing that applying a square wave and frequency of 1 kHz leads to uniform PAA-TiO(2) composite coatings on conductive materials.

  14. Plasma spray deposition of graded metal-ceramic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J. (Inst. of Tech. and Reliability of Structures, Czechoslovak Academy of Sciences, Plzen (Czechoslovakia)); Fiala, J. (Central Research Inst., Plzen (Czechoslovakia))

    1992-05-20

    Plasma spraying of graded coatings is described and the metal-ceramic interface of the graded intermediate zone is analysed in terms of a simple physical model. Special attention is devoted to the dominant deposition parameters, powder characteristics and the injector configuration for powder feeding, which play a fundamental role in graded coating deposition with controlled formation of a metal-ceramic intermediate zone. On the basis of a knowledge of these parameters, a new and original formula for the coefficient of homogeneity for simultaneous deposition of metal and ceramic particles at the same spot on the substrate is derived. Furthermore, very interesting topotactical relations are described for the metal-ceramic interface of the graded zone. Various techniques of structural analysis (X-ray diffraction, scanning electron microscopy, optical microscopy) and simple thermodynamic calculations allow a new interpretation to be given of the bonding between the metal and ceramic components. The cohesion of graded metal-ceramic coatings is predicted to be higher than that of ceramic coatings with a metallic bond layer. The results are illustrated by a NiCr-ZrO{sub 2}(MgO) graded coating. (orig.).

  15. CuSO4/H2O2-Induced Rapid Deposition of Polydopamine Coatings with High Uniformity and Enhanced Stability.

    Science.gov (United States)

    Zhang, Chao; Ou, Yang; Lei, Wen-Xi; Wan, Ling-Shu; Ji, Jian; Xu, Zhi-Kang

    2016-02-24

    Mussel-inspired polydopamine (PDA) deposition offers a promising route to fabricate multifunctional coatings for various materials. However, PDA deposition is generally a time-consuming process, and PDA coatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report a strategy to realize the rapid deposition of PDA by using CuSO4/H2O2 as a trigger. Compared to the conventional processes, our strategy shows the fastest deposition rate reported to date, and the PDA coatings exhibit high uniformity and enhanced stability. Furthermore, the PDA-coated porous membranes have excellent hydrophilicity, anti-oxidant properties, and antibacterial performance. This work demonstrates a useful method for the environmentally friendly, cost-effective, and time-saving fabrication of PDA coatings.

  16. The electrochemical deposition of tin-nickel alloys and the corrosion properties of the coating

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Møller, Per

    2005-01-01

    The electrodeposition of tin/nickel (65/35 wt%) is a unique coating process because of the deposition of an intermetallic phase of nickel and tin, which cannot be formed by any pyrometallurgical process. From thermodynamic calculations it can be shown that intermetallic phases can be formed through...... electrodeposition. The alloy has unique corrosion properties and exhibits surface passivation like stainless steel. The coating is decorative and non-allergic to the skin, can replace decorative nickel and nickel-chromium coatings in many cases and decreases the risk for allergic contact dermatitis. A number...... of electrochemical tests, including polarization curves, chronoamperometric studies and tribocorrosion tests have been performed to show the consequence of replacing nickel coatings with tin/nickel coatings....

  17. Characterization of 1064nm laser-induced damage on antireflection coatings grown by atomic layer deposition

    Science.gov (United States)

    Liu, Zhichao; Wei, Yaowei; Chen, Songlin; Luo, Jin; Ma, Ping

    2011-12-01

    Damage tests were carried out to measure the laser resistance of Al2O3/TiO2 and Al2O3/HfO2 antireflection coatings at 1064nm grown by atomic layer deposition (ALD). The S-on-1 and R-on-1 damage results are given. It's interesting to find that ALD coatings damage performance seems closed to those grown by conventional e-beam evaporation process. For Al2O3/TiO2 coatings, the grown temperature will impact the damage resistance of thin films. Crystallization of TiO2 layer at higher temperature could play an importance role as absorption defects that reduced the LIDT of coatings. In addition, it is found that using inorganic compound instead of organic compound as precursors for ALD process can effective prevent residual carbon in films and will increase the LIDT of coatings.

  18. Zirconia coatings deposited by novel plasma-enhanced aerosol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Miszczak, Sebastian; Pietrzyk, Bozena; Kucharski, Daniel [Institute of Materials Science and Engineering, Lodz University of Technology (Poland)

    2016-05-15

    The sol-gel technique is well known and widely used for manufacturing coatings. An aerosol-gel method is a modification of the classic sol-gel process. Preparation of coatings by this technique involves the formation of an aerosol and its deposition on the coated surfaces, where the aerosol droplets merge into a continuous layer. In this work, an aerosol-gel routine, enhanced with a low-temperature plasma discharge, was used to produce zirconia coatings on different substrates. Low-temperature plasma was used for preactivation of substrate surfaces prior to the sol deposition, and for treatment of deposited layers. The obtained coatings were characterized using optical, electron (SEM), and atomic force (AFM) microscopes, a contact-angle device, a scratch tester, a grazing-incidence X-ray diffractometer (GIXRD), and an infrared spectrometer (FTIR). The results showed a significant influence of substrate plasma pretreatment on the formation and morphology of zirconia thin films. A noticeable effect of low-temperature plasma treatment on the structure and properties of the obtained coatings was also presented. These results allow possible applications of this method for the preparation of zirconia coatings on temperature-sensitive substrates to be predicted. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Electrophoretic deposition of hydroxyapatite-hexagonal boron nitride composite coatings on Ti substrate.

    Science.gov (United States)

    Göncü, Yapıncak; Geçgin, Merve; Bakan, Feray; Ay, Nuran

    2017-10-01

    In this study, commercial pure titanium samples were coated with nano hydroxyapatite-nano hexagonal boron nitride (nano HA-nano hBN) composite by electrophoretic deposition (EPD). The effect of process parameters (applied voltage, deposition time and solid concentration) on the coating morphology, thickness and the adhesion behavior were studied systematically and crack free nano hBN-nano HA composite coating production was achieved for developing bioactive coatings on titanium substrates for orthopedic applications. For the examination of structural and morphological characteristics of the coating surfaces, various complementary analysis methods were performed. For the structural characterization, XRD and Raman Spectroscopy were used while, Scanning Electron Microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and Transmission Electron Microscopy (TEM) techniques were carried out for revealing the morphological characterization. The results showed that nano HA-nano hBN were successfully deposited on Ti surface with uniform, crack-free coating by EPD. The amounts of hBN in suspension are considered to have no effect on coating thickness. By adding hBN into HA, the morphology of HA did not change and hBN has no significant effect on porous structure. These nanostructured surfaces are expected to be suitable for proliferation of cells and have high potential for bioactive materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ion beam-assisted diamond-like carbon (DLC) coatings have beenused for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocompatibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp\\+3 bonds in the structure of mixed sp\\+2+sp\\+3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.

  1. Thermal Cycling Behavior of Quasi-Columnar YSZ Coatings Deposited by PS-PVD

    Science.gov (United States)

    Yang, Jiasheng; Zhao, Huayu; Zhong, Xinghua; Shao, Fang; Liu, Chenguang; Zhuang, Yin; Ni, Jinxing; Tao, Shunyan

    2017-01-01

    Columnar-structured thermal barrier coatings, owing to their high strain tolerance, are expected for their potential possibilities to substantially extend turbine lives and improve engine efficiencies. In this paper, plasma spray-physical vapor deposition (PS-PVD) process was used to deposit yttria partially stabilized zirconia (YSZ) coatings with quasi-columnar structures. Thermal cyclic tests on burner rigs and thermal shock tests by heating and water-quenching method were involved to evaluate the thermal cycling and thermal shock behaviors of such kind of structured thermal barrier coatings (TBCs). Evolution of the microstructures, phase composition, residual stresses and failure behaviors of quasi-columnar YSZ coatings before and after the thermal tests was investigated. The quasi-columnar coating obtained had an average life of around 623 cycles when the spallation area reached about 10% of the total coating surface during burner rig tests with the coating surface temperature of 1250 °C. Failure of the coating is mainly due to the break and pull-out of center columnar segments.

  2. Nanoscale precipitation coating: the deposition of inorganic films through step-by-step spray-assembly.

    Science.gov (United States)

    Popa, Gabriela; Boulmedais, Fouzia; Zhao, Peng; Hemmerlé, Joseph; Vidal, Loïc; Mathieu, Eric; Félix, Olivier; Schaaf, Pierre; Decher, Gero; Voegel, Jean-Claude

    2010-08-24

    Thin films and surface coatings play an important role in basic and applied research. Here we report on a new, versatile, and simple method ("precipitation coating") for the preparation of inorganic films, based on the alternate spraying of complementary inorganic salt solutions against a receiving surface on which the inorganic deposit forms. The method applies whenever the solubility of the deposited material is smaller than that of the salts in the solutions of the reactants. The film thickness is controlled from nanometers to hundreds of micrometers simply by varying the number of spraying steps; 200 spray cycles, corresponding to less than 15 min deposition time, yield films with thicknesses exceeding one micrometer and reaching tens of micrometers in some cases. The new solution-based process is also compatible with conventional layer-by-layer assembly and permits the fabrication of multimaterial sandwich-like coatings.

  3. Deposition of tantalum carbide coatings on graphite by laser interactions

    Science.gov (United States)

    Veligdan, James; Branch, D.; Vanier, P. E.; Barietta, R. E.

    1994-01-01

    Graphite surfaces can be hardened and protected from erosion by hydrogen at high temperatures by refractory metal carbide coatings, which are usually prepared by chemical vapor deposition (CVD) or chemical vapor reaction (CVR) methods. These techniques rely on heating the substrate to a temperature where a volatile metal halide decomposes and reacts with either a hydrocarbon gas or with carbon from the substrate. For CVR techniques, deposition temperatures must be in excess of 2000 C in order to achieve favorable deposition kinetics. In an effort to lower the bulk substrate deposition temperature, the use of laser interactions with both the substrate and the metal halide deposition gas has been employed. Initial testing involved the use of a CO2 laser to heat the surface of a graphite substrate and a KrF excimer laser to accomplish a photodecomposition of TaCl5 gas near the substrate. The results of preliminary experiments using these techniques are described.

  4. Development of electrophoretically deposited hydroxyapatite coatings on anodized nanotubular TiO{sub 2} structures: Corrosion and sintering temperature

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Mona; Batmanghelich, Farhad, E-mail: farhad.batmanghelich@rockets.utoledo.edu; Afshar, Abdollah; Dolati, Abolghasem; Mortazavi, Golsa

    2014-05-01

    Highlights: • HA nanoparticles were deposited on TiO{sub 2} nanotubular surface by EPD. • Nanotubular TiO{sub 2} structure enhances HA coating adhesion formed by EPD process. • Vacuum sintered coatings offered enhanced corrosion protection. • HA particles over TiO{sub 2} nanotubes decrease corrosion protection compared to their absence. - Abstract: Hydroxyapatite (HA) coatings in and onto anodized TiO{sub 2} nanotube arrays were presented and prepared by electrophoretic deposition technique (EPD). Coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). EPD proved to be an innovative and versatile technique to coat HA on and into nanotubular structures of TiO{sub 2} with enhanced adhesion between nanotubes and HA particles provided by mechanical interlocking. After EPD of HA on TiO{sub 2} layer, samples were sintered at 400 °C, 600 °C and 800 °C for 2 h in an Ar atmosphere. Effect of EPD processing parameters on thickness of the deposits and rate of deposition was elucidated for HA coatings on the nanotubular TiO{sub 2} structures. It was shown that higher applied voltages increase deposition rate and thickness of the coatings. Potentiodynamic polarization measurements proved corrosion protection caused by both HA coating and nanotubular TiO{sub 2} structure in simulated body fluid (SBF). Effect of sintering temperature on adhesion strength of HA coatings on TiO{sub 2} nanotubes and their composition were also studied.

  5. TiOxNy coatings grown by atmospheric pressure metal organic chemical vapor deposition

    OpenAIRE

    Maury, Francis; Duminica, Florin-Daniel

    2010-01-01

    International audience; Titanium oxynitride coatings were deposited on various substrates by an original atmospheric pressure metal organic chemical vapor deposition (MOCVD) process using titanium tetra-iso-propoxide as titanium and oxygen precursors and hydrazine as a nitrogen source. The films composition was monitored by controlling the N2H4 mole fraction in the initial reactive gas phase. The variation of the N content in the films results in significant changes in morphological, structur...

  6. 钛沉积工艺制备TiN/cBN和TiC/金钢石涂层颗粒%Fabrication of TiN/cBN and TiC/diamond coated particles by titanium deposition process

    Institute of Scientific and Technical Information of China (English)

    Walid M. DAOUSH; Hee S. PARK; Soon H. HONG

    2014-01-01

    Cubic boron nitride particles coated by titanium nitride (TiN/cBN) as well as diamond particles coated by titanium carbide (TiC/diamond) were prepared by Ti molten salt deposition followed by heat-treatment process. cBN or diamond particles were mixed separately with Ti powders and molten salts (KCl, NaCl and K2TiF6). The mixture was heated at 900 °C under argon atmosphere. The produced particles were heat-treated under hydrogen at 1000 °C. The morphologies and chemical compositions of the produced particles were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and focused ion beam (FIB). The results show that the cBN and the diamond particles are coated by nano-sized Ti layers. By heat-treatment of the Ti/cBN and TiC/diamond coated particles under hydrogen atmosphere, the deposited Ti layers were interacted by the in-situ transformation reaction with the surfaces of cBN and diamond particles and converted to titanium compounds (TiN and TiC), respectively.%用钛熔盐沉积及热处理工艺分别制备碳化钛涂覆的立方碳化硼颗粒(TiN/cBN)及碳化钛涂覆的金刚石颗粒(TiC/金刚石)。将cBN或金刚石颗粒分别与钛粉和KCl、NaCl和K2TiF6熔盐混合。将所得混合物在Ar气氛中加热至900°C,然后在H2气氛中于1000°C进行热处理。采用扫描电镜、X射线衍射和聚焦离子束技术对所制得颗粒进行表征。结果表明:cBN和金刚石颗粒表面已覆盖了纳米钛层。对Ti/cBN和TiC/金刚石涂层颗粒进行热处理后,颗粒表面沉积的Ti层与cBN和金刚石颗粒发生了原位化学反应,分别转化为钛化合物TiN和TiC。

  7. Atomic Layer Deposition for Coating of High Aspect Ratio TiO2 Nanotube Layers

    Science.gov (United States)

    2016-01-01

    We present an optimized approach for the deposition of Al2O3 (as a model secondary material) coating into high aspect ratio (≈180) anodic TiO2 nanotube layers using the atomic layer deposition (ALD) process. In order to study the influence of the diffusion of the Al2O3 precursors on the resulting coating thickness, ALD processes with different exposure times (i.e., 0.5, 2, 5, and 10 s) of the trimethylaluminum (TMA) precursor were performed. Uniform coating of the nanotube interiors was achieved with longer exposure times (5 and 10 s), as verified by detailed scanning electron microscopy analysis. Quartz crystal microbalance measurements were used to monitor the deposition process and its particular features due to the tube diameter gradient. Finally, theoretical calculations were performed to calculate the minimum precursor exposure time to attain uniform coating. Theoretical values on the diffusion regime matched with the experimental results and helped to obtain valuable information for further optimization of ALD coating processes. The presented approach provides a straightforward solution toward the development of many novel devices, based on a high surface area interface between TiO2 nanotubes and a secondary material (such as Al2O3). PMID:27643411

  8. Multiscale modeling, simulations, and experiments of coating growth on nanofibers. Part II. Deposition

    Science.gov (United States)

    Buldum, A.; Clemons, C. B.; Dill, L. H.; Kreider, K. L.; Young, G. W.; Zheng, X.; Evans, E. A.; Zhang, G.; Hariharan, S. I.

    2005-08-01

    This work is Part II of an integrated experimental/modeling investigation of a procedure to coat nanofibers and core-clad nanostructures with thin-film materials using plasma-enhanced physical vapor deposition. In the experimental effort, electrospun polymer nanofibers are coated with aluminum materials under different operating conditions to observe changes in the coating morphology. This procedure begins with the sputtering of the coating material from a target. Part I [J. Appl. Phys. 98, 044303 (2005)] focused on the sputtering aspect and transport of the sputtered material through the reactor. That reactor level model determines the concentration field of the coating material. This field serves as input into the present species transport and deposition model for the region surrounding an individual nanofiber. The interrelationships among processing factors for the transport and deposition are investigated here from a detailed modeling approach that includes the salient physical and chemical phenomena. Solution strategies that couple continuum and atomistic models are used. At the continuum scale, transport dynamics near the nanofiber are described. At the atomic level, molecular dynamics (MD) simulations are used to study the deposition and sputtering mechanisms at the coating surface. Ion kinetic energies and fluxes are passed from the continuum sheath model to the MD simulations. These simulations calculate sputtering and sticking probabilities that in turn are used to calculate parameters for the continuum transport model. The continuum transport model leads to the definition of an evolution equation for the coating-free surface. This equation is solved using boundary perturbation and level set methods to determine the coating morphology as a function of operating conditions.

  9. Surface Characteristics of Silicon Nanowires/Nanowalls Subjected to Octadecyltrichlorosilane Deposition and n-octadecane Coating.

    Science.gov (United States)

    Yilbas, Bekir Sami; Salhi, Billel; Yousaf, Muhammad Rizwan; Al-Sulaiman, Fahad; Ali, Haider; Al-Aqeeli, Nasser

    2016-12-09

    In this study, nanowires/nanowalls were generated on a silicon wafer through a chemical etching method. Octadecyltrichlorosilane (OTS) was deposited onto the nanowire/nanowall surfaces to alter their hydrophobicity. The hydrophobic characteristics of the surfaces were further modified via a 1.5-μm-thick layer of n-octadecane coating on the OTS-deposited surface. The hydrophobic characteristics of the resulting surfaces were assessed using the sessile water droplet method. Scratch and ultraviolet (UV)-visible reflectivity tests were conducted to measure the friction coefficient and reflectivity of the surfaces. The nanowires formed were normal to the surface and uniformly extended 10.5 μm to the wafer surface. The OTS coating enhanced the hydrophobic state of the surface, and the water contact angle increased from 27° to 165°. The n-octadecane coating formed on the OTS-deposited nanowires/nanowalls altered the hydrophobic state of the surface. This study provides the first demonstration that the surface wetting characteristics change from hydrophobic to hydrophilic after melting of the n-octadecane coating. In addition, this change is reversible; i.e., the hydrophilic surface becomes hydrophobic after the n-octadecane coating solidifies at the surface, and the process again occurs in the opposite direction after the n-octadecane coating melts.

  10. LDRD Project 52523 final report :Atomic layer deposition of highly conformal tribological coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Jungk, John Michael (University of Minnesota); Dugger, Michael Thomas; George, Steve M. (University of Colorado); Prasad, Somuri V.; Grubbs, Robert K.; Moody, Neville Reid; Mayer, Thomas Michael; Scharf, Thomas W.; Goeke, Ronald S.; Gerberich, William W. (University of Minnesota)

    2005-10-01

    Friction and wear are major concerns in the performance and reliability of micromechanical (MEMS) devices. While a variety of lubricant and wear resistant coatings are known which we might consider for application to MEMS devices, the severe geometric constraints of many micromechanical systems (high aspect ratios, shadowed surfaces) make most deposition methods for friction and wear-resistance coatings impossible. In this program we have produced and evaluate highly conformal, tribological coatings, deposited by atomic layer deposition (ALD), for use on surface micromachined (SMM) and LIGA structures. ALD is a chemical vapor deposition process using sequential exposure of reagents and self-limiting surface chemistry, saturating at a maximum of one monolayer per exposure cycle. The self-limiting chemistry results in conformal coating of high aspect ratio structures, with monolayer precision. ALD of a wide variety of materials is possible, but there have been no studies of structural, mechanical, and tribological properties of these films. We have developed processes for depositing thin (<100 nm) conformal coatings of selected hard and lubricious films (Al2O3, ZnO, WS2, W, and W/Al{sub 2}O{sub 3} nanolaminates), and measured their chemical, physical, mechanical and tribological properties. A significant challenge in this program was to develop instrumentation and quantitative test procedures, which did not exist, for friction, wear, film/substrate adhesion, elastic properties, stress, etc., of extremely thin films and nanolaminates. New scanning probe and nanoindentation techniques have been employed along with detailed mechanics-based models to evaluate these properties at small loads characteristic of microsystem operation. We emphasize deposition processes and fundamental properties of ALD materials, however we have also evaluated applications and film performance for model SMM and LIGA devices.

  11. Hydroxyapatite-Coated Magnesium-Based Biodegradable Alloy: Cold Spray Deposition and Simulated Body Fluid Studies

    Science.gov (United States)

    Noorakma, Abdullah C. W.; Zuhailawati, Hussain; Aishvarya, V.; Dhindaw, B. K.

    2013-10-01

    A simple modified cold spray process in which the substrate of AZ51 alloys were preheated to 400 °C and sprayed with hydroxyapatite (HAP) using high pressure cold air nozzle spray was designed to get biocompatible coatings of the order of 20-30 μm thickness. The coatings had an average modulus of 9 GPa. The biodegradation behavior of HAP-coated samples was tested by studying with simulated body fluid (SBF). The coating was characterized by FESEM microanalysis. ICPOES analysis was carried out for the SBF solution to know the change in ion concentrations. Control samples showed no aluminum corrosion but heavy Mg corrosion. On the HAP-coated alloy samples, HAP coatings started dissolving after 1 day but showed signs of regeneration after 10 days of holding. All through the testing period while the HAP coating got eroded, the surface of the sample got deposited with different apatite-like compounds and the phase changed with course from DCPD to β-TCP and β-TCMP. The HAP-coated samples clearly improved the biodegradability of Mg alloy, attributed to the dissolution and re-precipitation of apatite showed by the coatings as compared to the control samples.

  12. Performance properties of electro-spark deposited carbide-ceramic coatings modified by laser beam

    Science.gov (United States)

    Radek, Norbert; Bartkowiak, Konrad

    The work presented in this paper determines the influence of the laser treatment process on the properties of electrospark coatings. The properties after laser treatment were examined by microstructure analysis, microhardness, roughness and adhesion tests. The studies were conducted using WC-Co-Al2O3 electrodes produced by sintering nanostructural powders. The anti-wear coatings were first deposited by an EIL-8A apparatus on C45 carbon steel and then laser melted within various process parameters. In this case Nd:YAG laser (BLS 720 model) was applied. The electro-spark deposited coatings are very promising to improve abrasive wear resistance of tools and machine parts, which was indicated by tribological tests.

  13. UV protective zinc oxide coating for biaxially oriented polypropylene packaging film by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, Kimmo, E-mail: kimmo.lahtinen@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Kääriäinen, Tommi, E-mail: tommi.kaariainen@colorado.edu [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Johansson, Petri, E-mail: petri.johansson@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Kotkamo, Sami, E-mail: sami.kotkamo@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Maydannik, Philipp, E-mail: philipp.maydannik@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Seppänen, Tarja, E-mail: tarja.seppanen@lut.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland); Kuusipalo, Jurkka, E-mail: jurkka.kuusipalo@tut.fi [Paper Converting and Packaging Technology, Tampere University of Technology, P.O.Box 589, FI-33101 Tampere (Finland); Cameron, David C., E-mail: david.cameron@miktech.fi [ASTRaL, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli (Finland)

    2014-11-03

    Biaxially oriented polypropylene (BOPP) packaging film was coated with zinc oxide (ZnO) coatings by atomic layer deposition (ALD) in order to protect the film from UV degradation. The coatings were made at a process temperature of 100 °C using diethylzinc and water as zinc and oxygen precursors, respectively. The UV protective properties of the coatings were tested by using UV–VIS and infrared spectrometry, differential scanning calorimetry (DSC) and a mechanical strength tester, which characterised the tensile and elastic properties of the film. The results obtained with 36 and 67 nm ZnO coatings showed that the ZnO UV protective layer is able to provide a significant decrease in photodegradation of the BOPP film under UV exposure. While the uncoated BOPP film suffered a complete degradation after a 4-week UV exposure, the 67 nm ZnO coated BOPP film was able to preserve half of its original tensile strength and 1/3 of its elongation at break after a 6-week exposure period. The infrared analysis and DSC measurements further proved the UV protection of the ZnO coatings. The results show that a nanometre scale ZnO coating deposited by ALD is a promising option when a transparent UV protection layer is sought for polymer substrates. - Highlights: • Atomic layer deposited zinc oxide coatings were used as UV protection layers. • Biaxially oriented polypropylene (BOPP) film was well protected against UV light. • Formation of UV degradation products in BOPP was significantly reduced. • Mechanical properties of the UV exposed BOPP film were significantly improved.

  14. Synthesis and deposition of metal nanoparticles by gas condensation process

    Energy Technology Data Exchange (ETDEWEB)

    Maicu, Marina, E-mail: marina.maicu@fep.fraunhofer.de; Glöß, Daniel; Frach, Peter [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden (Germany); Schmittgens, Ralph; Gerlach, Gerald [Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany); Hecker, Dominic [Fraunhofer Institut für Elektronenstrahl und Plasmatechnik, FEP, Winterbergstraße 28, 01277 Dresden, Germany and Institut für Festkörperelektronik, IFE, TU Dresden, Helmholtz Straße 18, 01069 Dresden (Germany)

    2014-03-15

    In this work, the synthesis of Pt and Ag nanoparticles by means of the inert gas phase condensation of sputtered atomic vapor is presented. The process parameters (power, sputtering time, and gas flow) were varied in order to study the relationship between deposition conditions and properties of the nanoparticles such as their quantity, size, and size distribution. Moreover, the gas phase condensation process can be combined with a plasma enhanced chemical vapor deposition procedure in order to deposit nanocomposite coatings consisting of metallic nanoparticles embedded in a thin film matrix material. Selected examples of application of the generated nanoparticles and nanocomposites are discussed.

  15. Hydroxyapatite coatings deposited by liquid precursor plasma spraying: controlled dense and porous microstructures and osteoblastic cell responses

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yi; Song Lei; Liu Xiaoguang; Xiao Yanfeng; Wu Yao; Chen Jiyong; Wu Fang; Gu Zhongwei, E-mail: fangwu0808@yahoo.co, E-mail: fwu@scu.edu.c [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China)

    2010-12-15

    Hydroxyapatite coatings were deposited on Ti-6Al-4V substrates by a novel plasma spraying process, the liquid precursor plasma spraying (LPPS) process. X-ray diffraction results showed that the coatings obtained by the LPPS process were mainly composed of hydroxyapatite. The LPPS process also showed excellent control on the coating microstructure, and both nearly fully dense and highly porous hydroxyapatite coatings were obtained by simply adjusting the solid content of the hydroxyapatite liquid precursor. Scanning electron microscope observations indicated that the porous hydroxyapatite coatings had pore size in the range of 10-200 {mu}m and an average porosity of 48.26 {+-} 0.10%. The osteoblastic cell responses to the dense and porous hydroxyapatite coatings were evaluated with human osteoblastic cell MG-63, in respect of the cell morphology, proliferation and differentiation, with the hydroxyapatite coatings deposited by the atmospheric plasma spraying (APS) process as control. The cell experiment results indicated that the heat-treated LPPS coatings with a porous structure showed the best cell proliferation and differentiation among all the hydroxyapatite coatings. Our results suggest that the LPPS process is a promising plasma spraying technique for fabricating hydroxyapatite coatings with a controllable microstructure, which has great potential in bone repair and replacement applications.

  16. Synergistic effect between nano-ceramic lubricating additives and electroless deposited Ni-W-P coating

    Science.gov (United States)

    Chen, Min; Cheng, Wushan; Zhao, Zuxin; Huang, Xiaobo

    2013-01-01

    The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating (with heat treatment and in oil with nano-ceramic additives) has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.

  17. The effect of cladding speed on phase constitution and properties of AISI 431 stainless steel laser deposited coatings

    NARCIS (Netherlands)

    Hemmati, I.; Ocelik, V.; De Hosson, J. Th. M.

    2011-01-01

    Shorter processing time has given impetus to laser cladding technology and therefore in this research the AISI 431 martensitic stainless steel coatings are laser deposited at high cladding speeds, i.e. up to 117 mm/s. The analysis of phase constitution and functional properties of the coatings are p

  18. Plasma deposition of antimicrobial coating on organic polymer

    Science.gov (United States)

    Rżanek-Boroch, Zenobia; Dziadczyk, Paulina; Czajkowska, Danuta; Krawczyk, Krzysztof; Fabianowski, Wojciech

    2013-02-01

    Organic materials used for packing food products prevent the access of microorganisms or gases, like oxygen or water vapor. To prolong the stability of products, preservatives such as sulfur dioxide, sulfites, benzoates, nitrites and many other chemical compounds are used. To eliminate or limit the amount of preservatives added to food, so-called active packaging is sought for, which would limit the development of microorganisms. Such packaging can be achieved, among others, by plasma modification of a material to deposit on its surface substances inhibiting the growth of bacteria. In this work plasma modification was carried out in barrier discharge under atmospheric pressure. Sulfur dioxide or/and sodium oxide were used as the coating precursors. As a result of bacteriological studies it was found that sulfur containing coatings show a 16% inhibition of Salmonella bacteria growth and 8% inhibition of Staphylococcus aureus bacteria growth. Sodium containing coatings show worse (by 10%) inhibiting properties. Moreover, films with plasma deposited coatings show good sealing properties against water vapor. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

  19. Surface parameters modification by multilayer coatings deposition for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Zykova, A [Institute of Surface Engineering, 4 Zalutinskaya Str., Kharkov (Ukraine); Safonov, V [National Science Center, Kharkov Institute of Physics and Technology, 1 Akademicheskaja Str., 61108 Kharkov (Ukraine); Virva, O; Luk' yanchenko, V [Institute of Spine and Joint Pathologies, 80 Pushkinskaya Str., 61024 Kharkov (Ukraine); Walkowich, J; Rogowska, R [Institute for Sustainable Technologies, National Research Institute, 6/10 K. Pulaskiego Str., Radom (Poland); Yakovin, S [Department of Physical Technologies, Kharkov National University, 31 Kurchatov Ave., Kharkov (Ukraine)], E-mail: zykov@bi.com.ua

    2008-05-01

    Studies are presented of the surface parameters of various multilayer coatings, namely, TiN, CrN, (Ti, Cr)N, TiN/TiC{sub 10}N{sub 90}, TiN/TiC{sub 20}N{sub 80} deposited by means of Arc-PVD on stainless steel (1H18N9), as well as of the same coatings with an additional Al{sub 2}O{sub 3} film deposited by reactive magnetron sputtering (RMS). The surface thickness, roughness and topography are estimated. Other parameters, such as the surface free energy (SFE) and fractional polarity are determined by means of the Wu and the Owens-Wendt-Rabel-Kaelble methods. Experiments are carried out on the in vitro cell/material interaction (in a fibroblasts culture) in order to determine the materials biomedical response. The results show some correlation between the surface properties and cell adhesion. The best biological response parameters (cell number, proliferation function, morphology) are obtained in the case of coatings with the highest values of the polar part component of the SFE and the fractional polarity, such as TiN, TiN/TiC{sub 10}N{sub 90} and oxide coatings.

  20. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    Science.gov (United States)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  1. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    Science.gov (United States)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  2. Amorphous boron coatings produced with vacuum arc deposition technology

    CERN Document Server

    Klepper, C C; Yadlowsky, E J; Carlson, E P; Keitz, M D; Williams, J M; Zuhr, R A; Poker, D B

    2002-01-01

    In principle, boron (B) as a material has many excellent surface properties, including corrosion resistance, very high hardness, refractory properties, and a strong tendency to bond with most substrates. The potential technological benefits of the material have not been realized, because it is difficult to deposit it as coatings. B is difficult to evaporate, does not sputter well, and cannot be thermally sprayed. In this article, first successful deposition results from a robust system, based on the vacuum (cathodic) arc technology, are reported. Adherent coatings have been produced on 1100 Al, CP-Ti, Ti-6Al-4V, 316 SS, hard chrome plate, and 52 100 steel. Composition and thickness analyses have been performed by Rutherford backscattering spectroscopy. Hardness (H) and modules (E) have been evaluated by nanoindentation. The coatings are very pure and have properties characteristic of B suboxides. A microhardness of up to 27 GPa has been measured on a 400-nm-thick film deposited on 52 100 steel, with a corresp...

  3. Optimized plasma-deposited fluorocarbon coating for dry release and passivation of thin SU-8 cantilevers

    DEFF Research Database (Denmark)

    Keller, Stephan Urs; Häfliger, Daniel; Boisen, Anja

    2008-01-01

    Plasma-deposited fluorocarbon coatings are introduced as a convenient method for the dry release of polymer structures. In this method, the passivation process in a deep reactive ion etch reactor was used to deposit hydrophobic fluorocarbon films. Standard photolithography with the negative epoxy......-based photoresist SU-8 was used to fabricate polymer structures such as cantilevers and membranes on top of the nonadhesive release layer. The authors identify the plasma density as the main parameter determining the surface properties of the deposited fluorocarbon films. They show that by modifying the pressure...

  4. Lubricant-Infused Nanoparticulate Coatings Assembled by Layer-by-Layer Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sunny, S; Vogel, N; Howell, C; Vu, TL; Aizenberg, J

    2014-09-01

    Omniphobic coatings are designed to repel a wide range of liquids without leaving stains on the surface. A practical coating should exhibit stable repellency, show no interference with color or transparency of the underlying substrate and, ideally, be deposited in a simple process on arbitrarily shaped surfaces. We use layer-by-layer (LbL) deposition of negatively charged silica nanoparticles and positively charged polyelectrolytes to create nanoscale surface structures that are further surface-functionalized with fluorinated silanes and infiltrated with fluorinated oil, forming a smooth, highly repellent coating on surfaces of different materials and shapes. We show that four or more LbL cycles introduce sufficient surface roughness to effectively immobilize the lubricant into the nanoporous coating and provide a stable liquid interface that repels water, low-surface-tension liquids and complex fluids. The absence of hierarchical structures and the small size of the silica nanoparticles enables complete transparency of the coating, with light transmittance exceeding that of normal glass. The coating is mechanically robust, maintains its repellency after exposure to continuous flow for several days and prevents adsorption of streptavidin as a model protein. The LbL process is conceptually simple, of low cost, environmentally benign, scalable, automatable and therefore may present an efficient synthetic route to non-fouling materials.

  5. Processing and optimization of functional ceramic coatings and inorganic nanomaterials

    Science.gov (United States)

    Nyutu, Edward Kennedy G.

    Processing of functional inorganic materials including zero (0-D) dimensional (e.g. nanoparticles), 1-D (nanorods, nanofibers), and 2-D (films/coating) structures is of fundamental and technological interest. This research will have two major sections. The first part of section one focuses on the deposition of silicon dioxide onto a pre-deposited molybdenum disilicide coating on molybdenum substrates for both high (>1000 °C) and moderate (500-600 °C) temperature oxidation protection. Chemical vapor deposition (CVD/MOCVD) techniques will be utilized to deposit the metal suicide and oxide coatings. The focus of this study will be to establish optimum deposition conditions and evaluate the metal oxide coating as oxidation - thermal barriers for Mo substrates under both isothermal (static) and cyclic oxidation conditions. The second part of this section will involve a systematic evaluation of a boron nitride (BN) interface coating prepared by chemical vapor deposition. Ceramic matrix composites (CMCs) are prospective candidates for high (>1000 °C) temperature applications and fiber- matrix interfaces are the dominant design parameters in ceramic matrix composites (CMCs). An important goal of the study is to determine a set of process parameters, which would define a boron nitride (BN) interface coating by a chemical vapor deposition (CVD) process with respect to coating. In the first part of the second section, we will investigate a new approach to synthesize ultrafine metal oxides that combines microwave heating and an in-situ ultrasonic mixing of two or more liquid precursors with a tubular flow reactor. Different metal oxides such as nickel ferrite and zinc aluminate spinels will be studied. The synthesis of metal oxides were investigated in order to study the effects of the nozzle and microwave (INM process) on the purity, composition, and particle size of the resulting powders. The second part of this research section involves a study of microwave frequency

  6. Electrophoretic Deposition of Chitosan/45S5 Bioactive Glass Composite Coatings Doped with Zn and Sr.

    Science.gov (United States)

    Miola, Marta; Verné, Enrica; Ciraldo, Francesca Elisa; Cordero-Arias, Luis; Boccaccini, Aldo R

    2015-01-01

    In this research work, the original 45S5 bioactive glass was modified by introducing zinc and/or strontium oxide (6 mol%) in place of calcium oxide. Sr was added for its ability to stimulate bone formation and Zn for its role in bone metabolism, antibacterial properties, and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology while compositional analysis (EDS) demonstrated the effective incorporation of these elements in the glass network. Bioactivity test in simulated body fluid (SBF) up to 1 month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD). Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD) and alternating current EPD (AC-EPD). The stability of the suspension was analyzed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, whereas the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover, the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses, and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behavior of 45S5-Sr-containing coating while coatings containing Zn exhibited no hydroxyapatite formation.

  7. Electrophoretic deposition of chitosan/45S5 bioactive glass composite coatings doped with Zn and Sr

    Directory of Open Access Journals (Sweden)

    Marta eMiola

    2015-10-01

    Full Text Available In this research work the original 45S5 bioactive glass (BG was modified by introducing zinc and/or strontium oxide (6% mol in place of calcium oxide. Sr was added for its ability to stimulate bone formation, Zn for its role in bone metabolism, antibacterial properties and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology, while compositional analysis (EDS demonstrated the effective addition of these elements inside the glass network. Bioactivity test in simulated body fluid (SBF up to one month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD. Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD and alternating current EPD (AC-EPD. The stability of the suspension was analysed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, while the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behaviour of 45S5-Sr containing coating, while coatings containing Zn exhibited no hydroxyapatite formation.

  8. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    Science.gov (United States)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  9. Wear monitoring of protective nitride coatings using image processing

    DEFF Research Database (Denmark)

    Rasmussen, Inge Lise; Guibert, M.; Belin, M.

    2010-01-01

    A double-layer model system, consisting of a thin layer of tribological titanium aluminum nitride (TiAlN) on 17 top of titanium nitride (TiN), was deposited on polished 100Cr6 steel substrates. The TiAlN top-coatings 18 were exposed to abrasive wear by a reciprocating wear process in a linear tribo...... processing by color detection is a potential technique for early 25 warning or determination of residual thickness of tribological tool coatings prior to complete wear....

  10. Boron carbide coating deposition on tungsten substrates from atomic fluxes of boron and carbon

    Science.gov (United States)

    Sadovskiy, Y.; Begrambekov, L.; Ayrapetov, A.; Gretskaya, I.; Grunin, A.; Dyachenko, M.; Puntakov, N.

    2016-09-01

    A device used for both coating deposition and material testing is presented in the paper. By using lock chambers, sputtering targets are easily exchanged with sample holder thus allowing testing of deposited samples with high power density electron or ion beams. Boron carbide coatings were deposited on tungsten samples. Methods of increasing coating adhesion are described in the paper. 2 μm boron carbide coatings sustained 450 heating cycles from 100 to 900 C. Ion beam tests have shown satisfactory results.

  11. Cathodic micro-arc electro-deposition of ZrO2 coatings in an aqueous solution containing colloidal particles

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By a novel technique-cathodic micro-arc electro-deposition (CMED), ZrO2 coatings were deposited on an FeCrAl alloy. Experimental results show that the necessary conditions for obtaining ZrO2 coatings are to apply a pulse peak voltage over a critical value and add moderate amounts of ZrO2 colloidal particles and Zr(NO3)4 in the aqueous solution. The as-deposited coatings are porous because hydrogen, water, and other vapors are generated and released from the coatings to the solution during the spark reaction. The coatings contain monoclinic and tetragonal crystalline ZrO2with certain degree of amorphous structure. The processing parameters and mechanism of CMED were discussed.

  12. Corrosion Behavior of Cold Sprayed Titanium Coatings and Free Standing Deposits

    Science.gov (United States)

    Hussain, T.; McCartney, D. G.; Shipway, P. H.; Marrocco, T.

    2011-01-01

    Cold gas dynamic spraying can be used to deposit oxygen-sensitive materials, such as titanium, without significant chemical degradation of the powder. The process is thus believed to have potential for the deposition of corrosion-resistant barrier coatings. However, to be effective, a barrier coating must not allow ingress of a corrosive liquid and hence must not have interconnected porosity. This study investigated the effects of porosity on the corrosion behavior of cold sprayed titanium coatings onto carbon steel and also of free standing deposits. For comparative purposes, a set of free standing deposits was also vacuum heat-treated to further decrease porosity levels below those in the as-sprayed condition. Microstructures were examined by optical and scanning electron microscopy. Mercury intrusion porosimetry (MIP) was used to characterize the interconnected porosity over a size range of micrometers to nanometers. Open circuit potential (OCP) measurements and potentiodynamic polarization scans in 3.5 wt.% NaCl were used to evaluate the corrosion performance. The MIP results showed that in cold sprayed deposits a significant proportion of the porosity was sub-micron and so could not be reliably measured by optical microscope based image analysis. In the case of free standing deposits, a reduction in interconnected porosity resulted in a lower corrosion current density, a lower passive current density, and an increase in OCP closer to that of bulk titanium. For the lowest porosity level, ~1.8% achieved following vacuum heat treatment, the passive current density was identical to that of bulk titanium. However, electrochemical measurements of the coatings showed significant substrate influence when the interconnected porosity of the coating was 11.3 vol.% but a decreased substrate influence with a porosity level of 5.9 vol.%. In the latter case, the OCP was still around 250 mV below that of bulk Ti. Salt spray tests confirmed these electrochemical findings and

  13. Corrosion behavior of NiCrBSi coatings deposited by HVOF spraying

    Institute of Scientific and Technical Information of China (English)

    赵卫民; 王勇; 吴开源; 薛锦

    2003-01-01

    The corrosion resistance of NiCrBSi coating deposited on steel substrate by HVOF was examined using electrochemical tests and immersion tests so as to offer an experimental basis to expand a promising applied field of HVOF in aqueous medium, comparing with those of coatings deposited by oxyacetylene flame spraying and flame cladding. The results show that the general corrosion rate of HVOF sprayed coatings is quite bigger than that of clad coatings, but it is less sensitive to local corrosion. There is less and smaller porosity in the coatings deposited by HVOF than that in flame sprayed coatings. The effects of porosity on the corrosion current density was indistinctive, but the existence of large amount of defects in the coatings damaged the cohesion of the coatings, causing the metallic particles drop off from the coatings under the influence of corrosive medium. Improving the quality and reducing the porosity of coatings is the key to get the coatings with high corrosion resistance.

  14. Crystalline gamma-Al2O3 physical vapour deposition-coating for steel thixoforging tools.

    Science.gov (United States)

    Bobzin, K; Hirt, G; Bagcivan, N; Khizhnyakova, L; Ewering, M

    2011-10-01

    The process of thixoforming, which has been part of many researches during the last decades, combines the advantages of forging and casting for the shaping of metallic components. But due to the high temperatures of semi-solid steel alloys high demands on the tools are requested. To resists the thermal and mechanical loads (wear, friction, thermal and thermomechanical fatigue) protecting thin films are necessary. In this regard crystalline gamma-Al2O3 deposited via Physical Vapour Deposition (PVD) is a promising candidate: It exhibits high thermal stability, high oxidation resistance and high hot hardness. In the present work the application of a (Ti, Al)N/gamma-Al2O3 coating deposited by means of Magnetron Sputter Ion Plating in an industrial coating unit is presented. The coating was analysed by means of Rockwell test, nanoindentation, and Scanning Electron Microscopy (SEM). The coated tool was tested in thixoforging experiments with steel grade X210CrW12 (AlSI D6). The surface of the coated dies was examined with Scanning Electron Microscope (SEM) after 22, 42, 90 and 170 forging cycles.

  15. Electrophoretic deposition of PEEK-TiO 2 composite coatings on stainless steel

    KAUST Repository

    Seuß, Sigrid

    2012-03-01

    Electrophoretic deposition (EPD) has been successfully used to deposit composite coatings composed of polyetheretherketone (PEEK) and titanium dioxide (TiO 2) nanoparticles on 316L stainless steel substrates. The suspensions of TiO2 nanoparticles and PEEK microparticles for EPD were prepared in ethanol. PEEK-TiO 2 composite coatings were optimized using suspensions containing 6wt% PEEK-TiO 2 in ethanol with a 3:1 ratio of PEEK to TiO 2 in weight and by applying a potential difference of 30 V for 1 minute. A heat-treatment process of the optimized PEEK-TiO 2 composite coatings was erformed at 335°C for 30 minutes with a heating rate of 10°Cmin -1 to densify the deposits. The EPD coatings were microstructurally evaluated by scanning electron microscopy (SEM). It was demonstrated that EPD is a convenient and rapid method to fabricate PEEK/TiO 2 coatings on stainless steel which are interesting for biomedical applications. © (2012) Trans Tech Publications, Switzerland.

  16. Characterization and antibacterial performance of ZrCN/amorphous carbon coatings deposited on titanium implants

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chih-Ho [School of Medicine, China Medical University, Taichung, 404 Taiwan (China); Chang, Yin-Yu, E-mail: yinyu@mail2000.com.tw [Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin, Taiwan (China); Huang, Heng-Li [School of Dentistry, China Medical University, Taichung, Taiwan (China); Kao, Ho-Yi [Department of Materials Science and Engineering, Mingdao University, Changhua, Taiwan (China)

    2011-12-30

    Titanium (Ti)-based materials have been used for dental/orthopedic implants due to their excellent biological compatibility, superior mechanical strength and high corrosion resistance. The osseointegration of Ti implants is related to their composition and surface treatment. Better biocompatibility and anti-bacterial performances of Ti implant are beneficial for the osseointegration and for avoiding the infection after implantation surgery. In this study, nanocomposite ZrCN/amorphous carbon (a-C) coatings with different carbon contents were deposited on a bio-grade pure Ti implant material. A cathodic-arc evaporation system with plasma enhanced duct equipment was used for the deposition of ZrCN/a-C coatings. Reactive gas (N{sub 2}) and C{sub 2}H{sub 2} activated by the zirconium plasma in the evaporation process were used to deposit the ZrCN/a-C coatings. To verify the susceptibility of implant surface to bacterial adhesion, Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), one of the major pathogen frequently found in the dental implant-associated infections, was chosen for in vitro anti-bacterial analyses. In addition, the biocompatibility of human gingival fibroblast (HGF) cells on coatings was also evaluated by a cell proliferation assay. The results suggested that the ZrCN/a-C coatings with carbon content higher than 12.7 at.% can improve antibacterial performance with excellent HGF cell compatibility as well.

  17. Sustained release coating of tablets with Eudragit(®) RS/RL using a novel electrostatic dry powder coating process.

    Science.gov (United States)

    Qiao, Mingxi; Luo, Yanfeng; Zhang, Liqiang; Ma, Yingliang; Stephenson, Tyler Shawn; Zhu, Jesse

    2010-10-31

    The objectives of this study were to develop an electrostatic dry powder coating process for sustained coating tablets with Eudragit(®) RS/RL and to investigate the effects of various factors and operating conditions on the coating process and drug release profile. A liquid plasticizer (triethyl citrate) was sprayed onto the surface of the tablets followed by spraying coating powder by an electrostatic spray gun. The powder coated tablets were cured at elevated temperature for a film formation. Liquid plasticizer played important roles in lowering down the glass transition temperature (T(g)) of the coating polymer and increasing the surface electrical conduction of tablet cores. Electrostatic assisted coating deposition was confirmed by the fact that higher coating level was obtained with electrical charging than the ones without it. The micrographs of scanning electron microscopy (SEM) of coated tablets showed that the film formation mainly occurred during the curing step. Higher curing temperature and longer curing time help enhance the film formation. The in vitro drug release profiles indicated that curing time, temperature, coating level and ratio of Eudragit(®) RS/RL were the main factors affecting the sustained release profile. The electrostatic dry powder coating process has been demonstrated to be an alternative for tablet sustained release coating with Eudragit(®) RS and RL.

  18. Thermal conductivities of nanostructured magnesium oxide coatings deposited on magnesium alloys by plasma electrolytic oxidation.

    Science.gov (United States)

    Shen, Xinwei; Nie, Xueyuan; Hu, Henry

    2014-10-01

    The resistances of magnesium alloys to wear, friction and corrosion can be effectively improved by depositing coatings on their surfaces. However, the coatings can also reduce the heat transfer from the coated components to the surroundings (e.g., coated cylinder bores for internal combustion of engine blocks). In this paper, nanostructured magnesium oxides were produced by plasma electrolytic oxidation (PEO) process on the magnesium alloy AJ62 under different current densities. The guarded comparative heat flow method was adopted to measure the thermal conductivities of such coatings which possess gradient nanoscale grain sizes. The aim of the paper is to explore how the current density in the PEO process affects the thermal conductivity of the nanostructured magnesium coatings. The experimental results show that, as the current density rises from 4 to 20 A/mm2, the thermal conductivity has a slight increase from 0.94 to 1.21 W/m x K, which is significantly smaller than that of the corresponding bulk magnesium oxide materials (29.4 W/m x K). This mostly attributed to the variation of the nanoscale grain sizes of the PEO coatings.

  19. 工艺条件对水热电化学沉积 HA/TiO2涂层的影响%Effect of process conditions on HA/TiO2 coating deposited by hydrothermal-electrochemical deposition

    Institute of Scientific and Technical Information of China (English)

    徐敏; 马凤仓; 刘平; 李伟; 刘新宽; 陆晓琴

    2013-01-01

    采用微弧氧化法在钛合金表面制备出含有钙磷元素的TiO2氧化膜,利用水热电化学法制备了HA/TiO2涂层。借助SEM、XRD对涂层的表面形貌、物相组成进行了分析,研究了电流密度、温度和沉积时间对水热电化学沉积HA/TiO2涂层的影响。结果表明,含钙磷TiO2层有利于水热电化学方法生长HA,得到的HA晶体分布均匀、致密;随着温度的升高,HA晶体尺寸呈增大趋势;在一定范围内,HA晶体尺寸随沉积时间的延长呈增大趋势,若沉积时间过长,则HA晶体尺寸会出现异常粗大的现象;HA晶体尺寸随电流密度的升高变化不大。%TiO2 oxide films containing calcium and phosphorus were prepared by micro-arc oxidation ( MAO) on titanium alloy surface , HA/TiO2 coatings were prepared by using the hydrothermal-electrochemical method .The surface morphologies and phase compositions of coatings were analyzed by means of SEM and XRD , the effect of current density , temperature and deposition time on HA/TiO2 coating deposited by hydrothermal-electrochemical method was studied .The results show that the TiO 2 layer containing calcium and phosphorus contribute to the growth of HA in the hydrothermal-electrochemical process .HA crystals are well-distributed and compact in the coatings .The dimension of HA crystal remarkably increases with the temperature increasing .The dimension of HA crystal increases with the deposition time increasing within certain limits , but the dimension of HA crystal is abnormally large if the deposition time too long .The dimension of HA crystal changes slightly with the current density increasing .

  20. Corrosion properties of aluminium coatings deposited on sintered NdFeB by ion-beam-assisted deposition

    Science.gov (United States)

    Mao, Shoudong; Yang, Hengxiu; Li, Jinlong; Huang, Feng; Song, Zhenlun

    2011-04-01

    Pure Al coatings were deposited by direct current (DC) magnetron sputtering to protect sintered NdFeB magnets. The effects of Ar+ ion-beam-assisted deposition (IBAD) on the structure and the corrosion behaviour of Al coatings were investigated. The Al coating prepared by DC magnetron sputtering with IBAD (IBAD-Al-coating) had fewer voids than the coating without IBAD (Al-coating). The corrosion behaviour of the Al-coated NdFeB specimens was investigated by potentiodynamic polarisation, a neutral salt spray (NSS) test, and electrochemical impedance spectroscopy (EIS). The pitting corrosion of the Al coatings always began at the voids of the grain boundaries. Bombardment by the Ar+ ion-beams effectively improved the corrosion resistance of the IBAD-Al-coating.

  1. Structurally Integrated, Damage Tolerant Thermal Spray Coatings: Processing Effects on Surface and System Functionalities

    Science.gov (United States)

    Vackel, Andrew

    Thermal Spray (TS) coatings have seen extensive application as protective surfaces to enhance the service life of substrates prone to damage in their operating environment (wear, corrosion, heat etc.). With the advent of high velocity TS processes, the ability to deposit highly dense (>99%) metallic and cermet coatings has further enhanced the protective ability of these coatings. In addition to surface functionality, the influence of the coating application on the mechanical performance of a coated component is of great concern when such a component will experience either static or cyclic loading during service. Using a process mapping methodology, the processing-property interplay between coating materials meant to provide damage tolerant surface or for structural restoration are explored in terms of relevant mechanical properties. Most importantly, the residual stresses inherent in TS deposited coatings are shown to play a significant role in the integrated mechanical performance of these coatings. Unique to high velocity TS processes is the ability to produce compressive stresses within the deposit from the cold working induced by the high kinetic energy particles upon impact. The extent of these formation stresses are explored with different coating materials, as well as processing influence. The ability of dense TS coatings to carry significant structural load and synergistically strengthen coated tensile specimens is demonstrated as a function of coating material, processing, and thickness. The sharing of load between the substrate and otherwise brittle coating enables higher loads before yield for the bi-material specimens, offering a methodology to improve the tensile performance of coated components for structural repair or multi-functionality (surface and structure). The concern of cyclic fatigue damage in coated components is explored, since the majority of service application are designed for loading to be well below the yield point. The role of

  2. Brushite coatings on titanium for orthopedic implants: Studies on deposition and transformation

    Science.gov (United States)

    Kumar, Mukesh

    Hydroxyapatite (HA, Ca5(PO4)3OH) coating on the metallic substrate is expected to assist bone growth and implant integration. However, HA is quite stable in physiological solution and the use of other more reactive calcium phosphate ceramics (CPC) could induce faster bone growth by providing calcium and phosphate ions to the interacting physiological solution. This study utilized a non-line of sight electrodeposition process to achieve brushite (CaHPO4.2H2O) coatings. The uses of potassium or sodium chloride as a conducting electrolyte in the depositing bath enhanced deposition rates and altered the morphology of the coatings. Analysis suggested a strained deposit with sight specific substitution of cations from the conducting electrolyte. Such a deposit (modified brushite) was determined to have CaHPO 4.2H2O and CaY2(1-x)HPO4•2H 2O (x ˜0.95) with Y as Na0 or K. Whereas normal brushite was obtained from unsupported baths. The deposited mass of brushite increased with charge consumed and bonding to the substrate decreased with increasing deposition time. Though inconclusive. in-situ studies on electrodeposition did not rule out the possibility of ionic species responsible for the deposit. Transformations of both forms of brushite were investigated in calcium free Hank's type simulated body fluid. Modified brushite showed periodic appearance of freshly precipitated, but poorly crystalline HA, without the benefit of monetite (CaHPO4) as an intermediate. However, normal brushite transformation showed nonstoichiometric HA with monetite as an intermediate. Normal brushite demonstrated a slower transformation to HA when compared to the transformation kinetics of modified brushite. It is shown that lattice strain due to localized ion incorporation could be used to after the properties of brushite coatings to adjust the kinetics of transformation and indirectly the amount of calcium and phosphate ions released into the surrounding.

  3. 电泳-电沉积法制备超疏水Ni-PTFE复合镀层%Preparation of Super-hydrophobic Ni-PTFE Composite Coatings Using Electrophoretic-electrochemical Deposition Process

    Institute of Scientific and Technical Information of China (English)

    郝巧玲; 明平美; 崔天宏

    2014-01-01

    通过电泳-电沉积法制备具有超疏水特性的金属基镍(Ni)-聚四氟乙烯(PTFE)复合镀层。在改善搅拌方式和优选表面活性剂添加量的基础上,重点分析了电流密度和镀液中PTFE微粒子含量对镀层润湿性的影响。结果表明:在镀液中的PTFE微粒子含量>90 g/L、且每克PTFE (平均粒径0.2μm)辅助有65 mg的FC-134表面活性剂的条件下,能制备出具有超疏水与疏油特性的Ni-PTFE复合镀层。%In order to prepare the metal composite Ni-PTFE with superhydrophobic surface , anelectrophoretic-electrochemical deposition process was presented. After the appropriate mode for electrolyte stirring and the optimal amount of the selected additives being determined ,the effect of the current density applied and PTFE microparticle concentration in the electrolyte on the wettability of the prepared composite coatings was mainly investigated. Research results showed that ,Ni-PTFE composite coatings with superhydrophobic and oleophobic properties can be obtained from the electrodeposition bath having more than 90 g/L PTFE microparticles and quantitative additive which is added in terms of 65 mg surfactant FC-134 per gram PTFE.

  4. Transport processes in pea seed coats

    NARCIS (Netherlands)

    Dongen, Joost Thomas van

    2002-01-01

    The research described in this thesis concerns transport processes in coats of developing pea seeds. The scope of the investigation ranges from seed coat anatomy, via transport studies to the cloning of cDNA encoding proteinaceous membrane pores, and the heterologous expression of these protei

  5. Drastically Enhanced High-Rate Performance of Carbon-Coated LiFePO4 Nanorods Using a Green Chemical Vapor Deposition (CVD) Method for Lithium Ion Battery: A Selective Carbon Coating Process.

    Science.gov (United States)

    Tian, Ruiyuan; Liu, Haiqiang; Jiang, Yi; Chen, Jiankun; Tan, Xinghua; Liu, Guangyao; Zhang, Lina; Gu, Xiaohua; Guo, Yanjun; Wang, Hanfu; Sun, Lianfeng; Chu, Weiguo

    2015-06-03

    Application of LiFePO4 (LFP) to large current power supplies is greatly hindered by its poor electrical conductivity (10(-9) S cm(-1)) and sluggish Li+ transport. Carbon coating is considered to be necessary for improving its interparticle electronic conductivity and thus electrochemical performance. Here, we proposed a novel, green, low cost and controllable CVD approach using solid glucose as carbon source which can be extended to most cathode and anode materials in need of carbon coating. Hydrothermally synthesized LFP nanorods with optimized thickness of carbon coated by this recipe are shown to have superb high-rate performance, high energy, and power densities, as well as long high-rate cycle lifetime. For 200 C (18s) charge and discharge, the discharge capacity and voltage are 89.69 mAh g(-1) and 3.030 V, respectively, and the energy and power densities are 271.80 Wh kg(-1) and 54.36 kW kg(-1), respectively. The capacity retention of 93.0%, and the energy and power density retention of 93.6% after 500 cycles at 100 C were achieved. Compared to the conventional carbon coating through direct mixing with glucose (or other organic substances) followed by annealing (DMGA), the carbon phase coated using this CVD recipe is of higher quality and better uniformity. Undoubtedly, this approach enhances significantly the electrochemical performance of high power LFP and thus broadens greatly the prospect of its applications to large current power supplies such as electric and hybrid electric vehicles.

  6. A Modified Surface on Titanium Deposited by a Blasting Process

    Directory of Open Access Journals (Sweden)

    Caroline O’Sullivan

    2011-09-01

    Full Text Available Hydroxyapatite (HA coating of hard tissue implants is widely employed for its biocompatible and osteoconductive properties as well as its improved mechanical properties. Plasma technology is the principal deposition process for coating HA on bioactive metals for this application. However, thermal decomposition of HA can occur during the plasma deposition process, resulting in coating variability in terms of purity, uniformity and crystallinity, which can lead to implant failure caused by aseptic loosening. In this study, CoBlastTM, a novel blasting process has been used to successfully modify a titanium (V substrate with a HA treatment using a dopant/abrasive regime. The impact of a series of apatitic abrasives under the trade name MCD, was investigated to determine the effect of abrasive particle size on the surface properties of both microblast (abrasive only and CoBlast (HA/abrasive treatments. The resultant HA treated substrates were compared to substrates treated with abrasive only (microblasted and an untreated Ti. The HA powder, apatitic abrasives and the treated substrates were characterized for chemical composition, coating coverage, crystallinity and topography including surface roughness. The results show that the surface roughness of the HA blasted modification was affected by the particle size of the apatitic abrasives used. The CoBlast process did not alter the chemistry of the crystalline HA during deposition. Cell proliferation on the HA surface was also assessed, which demonstrated enhanced osteo-viability compared to the microblast and blank Ti. This study demonstrates the ability of the CoBlast process to deposit HA coatings with a range of surface properties onto Ti substrates. The ability of the CoBlast technology to offer diversity in modifying surface topography offers exciting new prospects in tailoring the properties of medical devices for applications ranging from dental to orthopedic settings.

  7. Chemical vapor deposited silica coatings for solar mirror protection

    Science.gov (United States)

    Gulino, Daniel A.; Dever, Therese M.; Banholzer, William F.

    1988-01-01

    A variety of techniques is available to apply protective coatings to oxidation susceptible spacecraft components, and each has associated advantages and disadvantages. Film applications by means of chemical vapor deposition (CVD) has the advantage of being able to be applied conformally to objects of irregular shape. For this reason, a study was made of the oxygen plasma durability of thin film (less than 5000 A) silicon dioxide coatings applied by CVD. In these experiments, such coatings were applied to silver mirrors, which are strongly subject to oxidation, and which are proposed for use on the space station solar dynamic power system. Results indicate that such coatings can provide adequate protection without affecting the reflectance of the mirror. Scanning electron micrographs indicated that oxidation of the silver layer did occur at stress crack locations, but this did not affect the measured solar reflectances. Oxidation of the silver did not proceed beyond the immediate location of the crack. Such stress cracks did not occur in thinner silica films, and hence such films would be desirable for this application.

  8. Protecting polymers in space with atomic layer deposition coatings.

    Science.gov (United States)

    Minton, Timothy K; Wu, Bohan; Zhang, Jianming; Lindholm, Ned F; Abdulagatov, Aziz I; O'Patchen, Jennifer; George, Steven M; Groner, Markus D

    2010-09-01

    Polymers in space may be subjected to a barrage of incident atoms, photons, and/or ions. Atomic layer deposition (ALD) techniques can produce films that mitigate many of the current challenges for space polymers. We have studied the efficacy of various ALD coatings to protect Kapton polyimide, FEP Teflon, and poly(methyl methacrylate) films from atomic-oxygen and vacuum ultraviolet (VUV) attack. Atomic-oxygen and VUV studies were conducted with the use of a laser-detonation source for hyperthermal O atoms and a D2 lamp as a source of VUV light. These studies used a quartz crystal microbalance (QCM) to monitor mass loss in situ, as well as surface profilometry and scanning electron microscopy to study the surface recession and morphology changes ex situ. Al2O3 ALD coatings protected the underlying substrates from atomic-oxygen attack, and the addition of TiO2 coatings protected the substrates from VUV-induced damage. The results indicate that ALD coatings can simultaneously protect polymers from oxygen-atom erosion and VUV radiation damage.

  9. Processing, characterization, and properties of some novel thermal barrier coatings

    Science.gov (United States)

    Jadhav, Amol D.

    The efficacy of ceramic thermal barrier coatings (TBCs) used to protect and to insulate metal components in engines increases with the thickness of the TBCs. However, the durabilities of thick TBCs deposited using conventional ceramic-coating deposition methods have not been adequate. Here the feasibility of depositing highly durable thick TBCs (1.5 to 4 mm thickness) of ZrO 2-7 wt.% Y2O3 (7YSZ) on bond-coated superalloy substrates using the solution-precursor plasma spray (SPPS) method has been demonstrated. Thermal cyclic durabilities of the thick SPPS TBCs have been shown to be much superior compared to TBCs deposited using the conventional air-plasma-spray (APS) process. To evaluate the performance of thick APS and SPPS TBCs, mechanical properties of free-standing coatings and coating/substrate interfaces have been determined experimentally. Additional evaluation of TBC performance has been obtained from studies of damage and development of thermally grown oxide (TGO) at the interface as a result of thermal cycling. The later results are used to suggest mechanisms of chemical failure of TGO in thick plasma-sprayed TBCs. Based on the experimental results and numerical analysis of the TBC residual stresses, the dramatic improvement in the thermal cycling life in the SPPS TBCs is attributed to superior mechanical properties of SPPS coatings. The presence of the strain tolerant vertical cracks in SPPS TBCs reduces the driving force for TBC spallation under mode-II loading. Additionally, high in-plane fracture toughness in the SPPS TBCs under mode-I loading delays the TBC spallation significantly. Finally, thermal conductivity of the SPPS TBCs has been reduced by microstructural tailoring. Analytical and object-oriented finite element (OOF) models have been used to analyze the experimental thermal conductivity data, and to predict thermal conductivities of engineered TBCs.

  10. Morphology, composition, and bioactivity of strontium-doped brushite coatings deposited on titanium implants via electrochemical deposition.

    Science.gov (United States)

    Liang, Yongqiang; Li, Haoyan; Xu, Jiang; Li, Xin; Qi, Mengchun; Hu, Min

    2014-06-04

    Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for use in dental applications. In this study, strontium-doped brushite coatings were deposited on titanium by electrochemical deposition. The phase composition of the coating was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction. The surface morphologies of the coatings were studied through scanning electron microscopy, and the cytocompatibility and bioactivity of the strontium-doped brushite coatings were evaluated using cultured osteoblasts. Osteoblast proliferation was enhanced by the addition of strontium, suggesting a possible mechanism by which strontium incorporation in brushite coatings increased bone formation surrounding the implants. Cell growth was also strongly influenced by the composition of the deposited coatings, with a 10% Sr-doped brushite coating inducing the greatest amount of bone formation among the tested materials.

  11. Morphology, Composition, and Bioactivity of Strontium-Doped Brushite Coatings Deposited on Titanium Implants via Electrochemical Deposition

    Directory of Open Access Journals (Sweden)

    Yongqiang Liang

    2014-06-01

    Full Text Available Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for use in dental applications. In this study, strontium-doped brushite coatings were deposited on titanium by electrochemical deposition. The phase composition of the coating was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction. The surface morphologies of the coatings were studied through scanning electron microscopy, and the cytocompatibility and bioactivity of the strontium-doped brushite coatings were evaluated using cultured osteoblasts. Osteoblast proliferation was enhanced by the addition of strontium, suggesting a possible mechanism by which strontium incorporation in brushite coatings increased bone formation surrounding the implants. Cell growth was also strongly influenced by the composition of the deposited coatings, with a 10% Sr-doped brushite coating inducing the greatest amount of bone formation among the tested materials.

  12. The study of Zn–Co alloy coatings electrochemically deposited by pulse current

    Directory of Open Access Journals (Sweden)

    Tomić Milorad V.

    2012-01-01

    Full Text Available The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2.

  13. The fabrication of carbon nanotubes reinforced copper coating by a kinetic spray process.

    Science.gov (United States)

    Xiong, Yuming; Kang, Kicheol; Yoon, Sanghoon; Lee, Changhee

    2008-10-01

    In this paper, multiwalled carbon nanotubes (MWCNTs) reinforced copper coating was deposited on copper sheet through kinetic spraying process. Effect of heat treatment on microstructure, conductivity, and hardness of the coating was investigated. The incompact MWCNTs reinforced copper coating exhibits a comparable hardness, but higher electrical resistivity than pure copper coating. After heat treatment at 600 degrees C for 2 h, the hardness of copper coatings significantly decreased due to the substantial grain growth. MWCNTs reinforced copper coating showed stable hardness and electrical conductivity against heat treatment owing to the inhibition of CNTs to grain growth and the intimate contact between CNTs and copper matrix.

  14. Thermal/residual stress in an electron beam physical vapor deposited thermal barrier coating system

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, J.; Jordan, E.H.; Barber, B.; Gell, M. [Univ. of Connecticut, Storrs, CT (United States)

    1998-10-09

    Elastic-plastic finite element models are used to define the thermal/residual stress state responsible for the observed failure behavior of an electron beam physical vapor deposited yttria stabilized zirconia thermal barrier coating on a Pt-Al bond coat. The failures were observed to start at grain boundary ridges, some of which evolved into oxide filled cavities. Finite element models are made of the actual interface geometries through the use of metallographic sectioning and imaging processing. There is a one to one correspondence of calculated tension in the oxide layer and the observed localized damage. Purely elastic analysis failed to show some important tensile regions associated with the observed failure.

  15. Porous nickel MCFC cathode coated by potentiostatically deposited cobalt oxide

    Energy Technology Data Exchange (ETDEWEB)

    Escudero, M.J.; Gonzalez, T.; Daza, L. [Dpto. Energia, CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Mendoza, L.; Cassir, M. [Instituto de Catalisis y Petroleoquimica (CSIC), Campus Cantoblanco, 28049 Madrid (Spain)

    2006-10-06

    Cobalt oxide was deposited on porous nickel by an electrodeposition technique as precursor of a novel MCFC cathode. The behavior of this cathode in molten (Li{sub 0.52}Na{sub 0.48}){sub 2}CO{sub 3} eutectics at 650{sup o}C under an atmosphere of CO{sub 2}:air (30:70) was studied before and after 50h of exposure by different techniques. Before the exposure, the deposit of cobalt corresponded to a Co{sub 3}O{sub 4} thin layer of. This crystalline structure was identified by XRD and Raman spectroscopy. After its exposure in the eutectic melt a loss of cobalt was observed by XRD, Raman spectroscopy, XPS, EDS and ICP-AES. The change in the Co{sub 3}O{sub 4} structure into lithium-cobalt-nickel oxide (LiCo{sub 1-y}Ni{sub y}O{sub 2}) was observed by Raman spectroscopy. The SEM micrographs for Co{sub 3}O{sub 4}-coated porous nickel showed different angular shapes with respect to porous Ni. The nickel solubility for the coated porous nickel, measured by ICP-AES, decreased with respect to uncoated nickel. The Co{sub 3}O{sub 4}-coated porous nickel cathode showed, after its immersion in the molten carbonate melt, a similar porosity but a higher pore size. LiCo{sub 1-y}Ni{sub y}O{sub 2}-coated NiO offers interesting features which combine the properties of nickel, lithium and cobalt in molten carbonate. This could be a promising novel MCFC cathode material. (author)

  16. Morphology, Composition, and Bioactivity of Strontium-Doped Brushite Coatings Deposited on Titanium Implants via Electrochemical Deposition

    OpenAIRE

    2014-01-01

    Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for use in dental applications. In this study, strontium-doped brushite coatings were deposited on titanium by electrochemical deposition. The phase composition of the coating was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction. The surface morphologies of the coatings were studied through scanning electron microscopy, and the cytocompatibility and...

  17. Correlation between optical emission spectra and the process parameters of a 915 MHz microwave plasma CVD reactor used for depositing polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Awadesh Kumar Mallik; Sandip Bysakh; Someswar Dutta; Debabrata Basu

    2014-08-01

    In this paper, the hydrogen and hydrogen-methane mixed plasma have been generated inside a 33 cm diameter quartz bell jar with a low power (9 KW) and lower frequency 915 MHz microwave plasma chemical vapor deposition system. The reactor is being used for growing polycrystalline diamond (PCD) over large area (100 mm). The generated plasma is diagnosed by in situ optical emission spectroscopy method with wave length ranging from 200 to 900 nm. The effects of microwave power, chamber pressure and gas concentration on plasma characteristics have been studied in this work. Within the optical range, Balmer H, H, C2swan band and CH lines have been detected at the wavelengths of 655.95, 485.7, 515.82 and 430.17 nm, respectively. It has been observed that for hydrogen plasma, the amount of transition from hydrogen atom inner shell 3 to 2 (H) is almost constant with increasing microwave (MW) power (from 2000 to 2800 W) and pressure (from 15 to 30 Torr) initially, after that it increases with further increase of MW power and pressure, whereas, the transition from 4 to 2 (H) is slowly increased with increasing MW power and pressure. For hydrogen-methane plasma, intensities of C2 swan band, i.e., the transitions from D$^3\\Pi_\\text{g}$ to A$^3\\Pi_{\\mu}$ energy levels, are also increased with the increasing microwave power and reactor pressure. It has been observed that the radicals present in the plasma are affected by variation of different reactor parameters like pressure, MW power, CH4 concentration, etc.

  18. Morphology control in thin films of PS:PLA homopolymer blends by dip-coating deposition

    Science.gov (United States)

    Vital, Alexane; Vayer, Marylène; Tillocher, Thomas; Dussart, Rémi; Boufnichel, Mohamed; Sinturel, Christophe

    2017-01-01

    In this work, smooth polymer films of PS, PLA and their blends, with thicknesses ranging from 20 nm up to 400 nm and very few defects on the surface were obtained by dip-coating. In contrast to the process of spin-coating which is conventionally used to prepare thin films of polymer blends, we showed that depending on the deposition parameters (withdrawal speed and geometry of the reservoir), various morphologies such as layered films and laterally phase-separated domains could be formed for a given blend/solvent pair, offering much more opportunities compared to the spin-coating process. This diversity of morphologies was explained by considering the superposition of different phenomena such as phase separation process, dewetting and vitrification in which parameters such as the drying time, the compatibility of the polymer/solvent pairs and the affinity of the polymer towards the interfaces were suspected to play a significant role. For that purpose, the process of dip-coating was examined within the capillary and the draining regimes (for low and high withdrawal speed respectively) in order to get a full description of the thickness variation and evaporation rate as a function of the deposition parameters.

  19. Processing on high efficiency solar collector coatings

    Science.gov (United States)

    Roberts, M.

    1977-01-01

    Wavelength selective coatings for solar collectors are considered. Substrates with good infrared reflectivity were examined along with their susceptibility to physical and environmental damage. Improvements of reflective surfaces were accomplished through buffing, chemical polishing and other surface processing methods.

  20. Boron carbide coating deposition on tungsten and testing of tungsten layers and coating under intense plasma load

    Energy Technology Data Exchange (ETDEWEB)

    Airapetov, A. A.; Begrambekov, L. B., E-mail: lbb@plasma.mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation); Buzhinskiy, O. I. [State Research Center Troitsk Institute for Innovation and Fusion Research (TRINITI) (Russian Federation); Grunin, A. V.; Gordeev, A. A.; Zakharov, A. M.; Kalachev, A. M.; Sadovskiy, Ya. A.; Shigin, P. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2015-12-15

    A device intended for boron carbide coating deposition and material testing under high heat loads is presented. A boron carbide coating 5 μm thick was deposited on the tungsten substrate. These samples were subjected to thermocycling loads in the temperature range of 400–1500°C. Tungsten layers deposited on tungsten substrates were tested in similar conditions. Results of the surface analysis are presented.

  1. Boron carbide coating deposition on tungsten and testing of tungsten layers and coating under intense plasma load

    Science.gov (United States)

    Airapetov, A. A.; Begrambekov, L. B.; Buzhinskiy, O. I.; Grunin, A. V.; Gordeev, A. A.; Zakharov, A. M.; Kalachev, A. M.; Sadovskiy, Ya. A.; Shigin, P. A.

    2015-12-01

    A device intended for boron carbide coating deposition and material testing under high heat loads is presented. A boron carbide coating 5 μm thick was deposited on the tungsten substrate. These samples were subjected to thermocycling loads in the temperature range of 400-1500°C. Tungsten layers deposited on tungsten substrates were tested in similar conditions. Results of the surface analysis are presented.

  2. Modelling and analysis of sputter deposited ZrN coating by CFD

    Science.gov (United States)

    Kapopara, Jaydeep M.; Mengar, Akshaykumar R.; Chauhan, Kamlesh V.; Patel, Nicky P.; Rawal, Sushant K.

    2016-09-01

    The objective of the present work is to investigate the effect of various sputtering parameters such as velocity, mass flow rate on velocity profiles, pressure profiles, density profiles and concentration distribution of the process gases (argon and nitrogen) of zirconium nitride films deposited on glass and silica substrate by RF magnetron sputtering. A three dimensional Computational Fluid Dynamics (CFD) study has been carried out using Fluent-ANSYS commercial code to visualize the mixing behavior of process gases inside the deposition chamber. The results show that the location of gas inlet port has a greater influence on gas distribution inside the chamber where reactive gas will form coating. By having this information, one can able to modify the reactor geometry and gas flow openings along with its positions for better gas flow over the substrate which in turns gives an indirect indication of coating from the composition point of view.

  3. Turbine repair process, repaired coating, and repaired turbine component

    Energy Technology Data Exchange (ETDEWEB)

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  4. Properties of Aluminum Deposited by a High-Velocity Oxygen-Fueled Process

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R; Decker, T A; Gansert, R V; Gansert, D; Lee, D

    2001-06-12

    Aluminum coatings deposited by a HVOF process have been demonstrated and relevant coating properties evaluated according to two deposition parameters, the spray distance and the oxygen-to-fuel flow ratio. The coating porosity, surface roughness, and microhardness are measured. The coating properties are fairly insensitive to spray distance, the distance between the nozzle and the workpiece, and fuel ratios, the oxygen-to-fuel flow. Increasing the fuel content does appear to improve the process productivity in terms of surface roughness. Minimization of nozzle loading is discussed.

  5. Recent Advances in the Deposition of Diamond Coatings on Co-Cemented Tungsten Carbides

    Directory of Open Access Journals (Sweden)

    R. Polini

    2012-01-01

    Full Text Available Co-cemented tungsten carbides, namely, hard metals are largely used to manufacture high wear resistant components in several manufacturing segments. Coating hard metals with superhard materials like diamond is of utmost interest as it can further extend their useful lifespan. The deposition of diamond coatings onto WC-Co can be extremely complicated as a result of poor adhesion. This can be essentially ascribed to (i the mismatch in thermal expansion coefficients between diamond and WC-Co, at the typical high temperatures inside the chemical vapour deposition (CVD chamber, generates large residual stresses at the interface; (ii the role of surface Co inside the WC-Co matrix during diamond CVD, which promotes carbon dissolution and diffusion. The present investigation reviews the techniques by which Co-cemented tungsten carbides can be treated to make them prone to receive diamond coatings by CVD. Further, it proposes interesting ecofriendly and sustainable alternatives to further improve the diamond deposition process as well as the overall performance of the coated hard metals.

  6. Sol-gel synthesis of 45S5 bioglass – Prosthetic coating by electrophoretic deposition

    Directory of Open Access Journals (Sweden)

    Faure Joel

    2013-11-01

    Full Text Available In this work, the 45S5 bioactive glass has been prepared by the sol-gel process using an organic acid catalyst instead of nitric acid usually used. The physico-chemical and structural characterizations confirmed and validated the elemental composition of the resulting glass. In addition, the 45S5 bioactive glass powder thus obtained was successfully used to elaborate by electrophoretic deposition a prosthetic coating on titanium alloy Ti6Al4V.

  7. Epitaxial solution deposition of YBa2Cu3O7-6 coated conductors.

    Energy Technology Data Exchange (ETDEWEB)

    Overmyer, Donald L.; Clem, Paul Gilbert; Siegal, Michael P.; Holesinger, Terry A. (Los Alamos National Laboratory, Los Alamos, NM); Voigt, James A.; Richardson, Jacob J.; Dawley, Jeffrey Todd

    2004-11-01

    A variety of solution deposition routes have been reported for processing complex perovskite-based materials such as ferroelectric oxides and conductive electrode oxides, due to ease of incorporating multiple elements, control of chemical stoichiometry, and feasibility for large area deposition. Here, we report an extension of these methods toward long length, epitaxial film solution deposition routes to enable biaxially oriented YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO)-coated conductors for superconducting transmission wires. Recent results are presented detailing an all-solution deposition approach to YBCO-coated conductors with critical current densities J{sub c} (77 K) > 1 MA/cm{sup 2} on rolling-assisted, biaxially textured, (200)-oriented Ni-W alloy tapes. Solution-deposition methods such as this approach and those of other research groups appear to have promise to compete with vapor phase methods for superconductor electrical properties, with potential advantages for large area deposition and low cost/kA {center_dot} m of wire.

  8. Cathodic electrophoretic deposition ofα-Fe2O3 coating

    Institute of Scientific and Technical Information of China (English)

    马莉; 常通; 李小斌; 李志友; 张斗; 周科朝

    2015-01-01

    Submicroα-Fe2O3 coatings were formed using electrophoretic deposition (EPD) technique in aqueous media. The zeta potentials of differentα-Fe2O3 suspensions with different additives were measured as a function of pH to identify the optimum suspension condition for deposition. Electrophoretic depositions ofα-Fe2O3 coatings under different applied electric fields and deposition time were studied and the effects of applied voltages and deposition time on deposition rates and thicknesses were investigated. The particle packing densities of the deposits at various applied voltages and deposition time were also analyzed by a scanning electron microscope (SEM). The results show that crack-freeα-Fe2O3 coatings with uniform microstructure and good adherence to the nickel substrates are successfully obtained. Electrophoretic depositedα-Fe2O3 coating from aqueous suspension is a feasible, low-cost and environmental friendly method.

  9. Glassy Carbon Coating Deposited on Hybrid Structure of Composite Materials

    Directory of Open Access Journals (Sweden)

    Posmyk A.

    2016-06-01

    Full Text Available This paper presents a method of production metal matrix composites with aluminum oxide foam covered by glassy carbon layer used as reinforcement. The glassy carbon coating was formed for decreasing of friction coefficient and reducing the wear. In first step of technology liquid glassy carbon precursor is on ceramic foam deposited, subsequently cured and carbonated at elevated temperature. In this way ceramic foam is covered with glassy carbon coating with thickness of 2-8 μm. It provides desirable amount of glassy carbon in the structure of the material. In the next step, porous spheres with carbon coating are infiltrated by liquid matrix of Al-Cu-Mg alloy. Thereby, equable distribution of glassy carbon in composite volume is achieved. Moreover, typical problems for composites reinforced by particles like sedimentation, agglomeration and clustering of particles are avoided. Tribological characteristics during friction in air versus cast iron as a counterpart were made. Produced composites with glassy carbon layer are characterised by friction coefficient between 0.08-0.20, thus meeting the typical conditions for solid lubricants.

  10. Interface behavior of tungsten coating on stainless steel by electro spark deposition

    Directory of Open Access Journals (Sweden)

    Wang Yuangang

    2015-01-01

    Full Text Available A new method of electro spark deposition method was put forward, which was based on the theory of electro spark deposition by changing the polarity in the liquid. Tungsten coating layers was produced on surface of Stainless Steel by electro spark deposition. The micro hardness, microstructure, chemical composition and phases of the coating layer were examined by means of hardness test, scanning electron microscopy (SEM and energy dispersive spectrometer (EDS analysis. The results showed that there was tungsten coating in the surface, which was discontinuous. Microhardness of the coating layer was about 3 times more than that of the substrate. The combination between coating layer and substrate was metallurgical bond.

  11. Thermal Imaging Processes of Polymer Nanocomposite Coatings

    Science.gov (United States)

    Meth, Jeffrey

    2015-03-01

    Laser induced thermal imaging (LITI) is a process whereby infrared radiation impinging on a coating on a donor film transfers that coating to a receiving film to produce a pattern. This talk describes how LITI patterning can print color filters for liquid crystal displays, and details the physical processes that are responsible for transferring the nanocomposite coating in a coherent manner that does not degrade its optical properties. Unique features of this process involve heating rates of 107 K/s, and cooling rates of 104 K/s, which implies that not all of the relaxation modes of the polymer are accessed during the imaging process. On the microsecond time scale, the polymer flow is forced by devolatilization of solvents, followed by deformation akin to the constrained blister test, and then fracture caused by differential thermal expansion. The unique combination of disparate physical processes demonstrates the gamut of physics that contribute to advanced material processing in an industrial setting.

  12. Kinetics of niobium carbide coating produced on AISI 1040 steel by thermo-reactive deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ugur

    2004-07-15

    There are a lot of technologically interesting characteristics of niobium carbide coating deposited by pack method which is the production of hard, wear-resistant, oxidation and corrosion resistant coating layer on the steel substrates. In the present study, the growth kinetics of niobium carbide layer deposited by thermo-reactive diffusion techniques in a solid medium on steel samples was reported. Niobium carbide coating treatment was performed on AISI 1040 steels in the powder mixture consisting of ferro-niobium, ammonium chloride and alumina at 1073, 1173 and 1273 K for 1-4 h. The presence of NbC and Nb{sub 2}C phases formed on the surface of the steel substrates was confirmed by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction analyses. Niobium carbide layer thickness ranges from 3.42{+-}0.52 to 11.78{+-}2.29 {mu}m depending upon the treatment time and temperature. Layer growth kinetics was analyzed by measuring the depth of niobium carbide layer as a function of time and temperature. The kinetics of niobium carbide coating by pack method shows a parabolic relationship between carbide layer thickness and treatment time, and the activation energy for the process is estimated to be 91.257 kJ mol{sup -1}. Moreover, an attempt was made to investigate the possibility of predicting the contour diagram of niobium carbide layer variation and to establish some empirical relationships between process parameters and niobium carbide layer thickness.

  13. Physical chemistry of WC-12 %Co coatings deposited by thermal spraying at different standoff distances

    Energy Technology Data Exchange (ETDEWEB)

    Afzal, Muhammad; Ahmed, Furqan; Anwar, Muhammad Yousaf; Ali, Liaqat; Ajmal, Muhammad [Univ. of Engineering and Technology, Metallurgical and Materials Engineering, Lahore (Pakistan); Khan, Aamer Nusair [Institute of Industrial and Control System, Rawalpindi (Pakistan)

    2015-09-15

    In the present research, WC-12 %Co cermet coatings were deposited on AISI-321 stainless steel substrate using air plasma spraying. During the deposition process, the standoff distance was varied from 80 to 130 mm with 10 mm increments. Other parameters such as current, voltage, time, carrier gas flow rate and powder feed rate etc. were kept constant. The objective was to study the effects of spraying distance on the microstructure of as-sprayed coatings. The microscopic analyses revealed that the band of spraying distance ranging from 90 to 100 mm was the threshold distance for optimum results, provided that all the other spraying parameters were kept constant. In this range of threshold distance, minimum percentages of porosity and defects were observed. Further, the formation of different phases, at six spraying distances, was studied using X-ray diffraction, and the phase analysis was correlated with hardness results.

  14. Study of preparation of BG/HA gradient coating on titanium alloy by electrophoretic deposition method

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-ming; HAN Qing-rong; LI Shi-pu; XU Chuan-bo

    2001-01-01

    In this paper, a gradient bioactive coating made from modified bioglass (BG) and hydroxyapatite (HA) was prepared by electrophoretic deposition method(EPD)on the surface of titanium alloy. Strong bonding between the matrix and BG/HA gradient coating was got by sintering. Crystal composition of the coating was analyzed by XRD. The characteristics of surface and cross section of the coating were observed by SEM. Adhesive strength of the coating was tested by pull method. The optimizing technological parameters were determined.

  15. Electrochemical deposition of Ni–TiN nanocomposite coatings and the effect of sodium dodecyl sulphate surfactant on the coating properties

    Indian Academy of Sciences (India)

    NAFISE PARHIZKAR; ABOLGHASEM DOLATI; ROYA AGHABABAZADEH; ZAHRA LALEGANI

    2016-08-01

    Ni–TiN nanocomposite coatings were prepared by using electrochemical deposition in a Watt’s bath containing TiN particles to increase the hardness of Ni. The effects of deposition current density, electrolyte agitation speed and the number of particles in the solution on the amount of incorporated particles in the coating process were investigated. The optimum deposition current density of 4 A dm$^{−2}$ and agitation speed of 450 rpm were obtained. The effect of sodium dodecyl sulphate (SDS) anionic surfactant on the amount of particles in the coatings was investigated. It was observed that the maximum amount of incorporated particles, with a value of 7.5% by volume, was created in the current density of 4 A dm$^{−2}$, stirring rate of 450 rpm, 30 g l$^{−1}$ TiN particles and in the presence of 0.6 g l$^{−1}$ SDS anionic surfactant.

  16. Process optimization of ultrasonic spray coating of polymer films

    DEFF Research Database (Denmark)

    Bose, Sanjukta; Keller, Stephan Sylvest; Boisen, Anja

    2013-01-01

    In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 μm) and low roughness compared to the film thickness. The coatings are characterized with respect...... these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating...... to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model...

  17. Thin film deposition at atmospheric pressure using dielectric barrier discharges: Advances on three-dimensional porous substrates and functional coatings

    Science.gov (United States)

    Fanelli, Fiorenza; Bosso, Piera; Mastrangelo, Anna Maria; Fracassi, Francesco

    2016-07-01

    Surface processing of materials by atmospheric pressure dielectric barrier discharges (DBDs) has experienced significant growth in recent years. Considerable research efforts have been directed for instance to develop a large variety of processes which exploit different DBD electrode geometries for the direct and remote deposition of thin films from precursors in gas, vapor and aerosol form. This article briefly reviews our recent progress in thin film deposition by DBDs with particular focus on process optimization. The following examples are provided: (i) the plasma-enhanced chemical vapor deposition of thin films on an open-cell foam accomplished by igniting the DBD throughout the entire three-dimensional (3D) porous structure of the substrate, (ii) the preparation of hybrid organic/inorganic nanocomposite coatings using an aerosol-assisted process, (iii) the DBD jet deposition of coatings containing carboxylic acid groups and the improvement of their chemical and morphological stability upon immersion in water.

  18. Convergent spray process for environmentally friendly coatings

    Science.gov (United States)

    Scarpa, Jack

    1995-01-01

    Conventional spray application processes have poor transfer efficiencies, resulting in an exorbitant loss in materials, solvents, and time. Also, with ever tightening Environmental Protection Agency (EPA) regulations and Occupational Safety and Health Administration requirements, the low transfer efficiencies have a significant impact on the quantities of materials and solvents that are released into the environment. High solids spray processes are also limited by material viscosities, thus requiring many passes over the surface to achieve a thickness in the 0.125 -inch range. This results in high application costs and a negative impact on the environment. Until recently, requirements for a 100 percent solid sprayable, environmentally friendly, lightweight thermal protection system that can be applied in a thick (greater than 0.125 inch) single-pass operation exceeded the capability of existing systems. Such coatings must be applied by hand lay-up techniques, especially for thermal and/or fire protection systems. The current formulation of these coatings has presented many problems such as worker safety, environmental hazards, waste, high cost, and application constraints. A system which can apply coatings without using hazardous materials would alleviate many of these problems. Potential applications include the aerospace thermal protective specialty coatings, chemical and petroleum industries that require fire-protection coatings that resist impact, chemicals, and weather. These markets can be penetrated by offering customized coatings applied by automated processes that are environmentally friendly.

  19. Application of Taguchi Method to the Optimization of a-C:H Coatings Deposited Using Ion Beam Assisted Physical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    W. H. Kao

    2015-02-01

    Full Text Available The Taguchi design method is used to optimize the adhesion, hardness, and wear resistance properties of a-C:H coatings deposited on AISI M2 steel substrates using the ion beam assisted physical vapor deposition method. The adhesion strength of the coatings is evaluated by means of scratch tests, while the hardness is measured using a nanoindentation tester. Finally, the wear resistance is evaluated by performing cyclic ball-on-disc wear tests. The Taguchi experimental results show that the optimal deposition parameters are as follows: a substrate bias voltage of 90 V, an ion beam voltage of 1 kV, an acetylene flow rate of 21 sccm, and a working distance of 7 cm. Given these optimal processing conditions, the a-C:H coating has a critical load of 99.8 N, a hardness of 25.5 GPa, and a wear rate of 0.4 × 10−6 mm3/Nm.

  20. Pool Boiling Heat Transfer Characteristics of Chromium Coatings Deposited by RF Magnetron Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Gwang Hyeok; Son, Hong Hyun; Jeong, Uiju; Jeun, Gyoodong; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2015-05-15

    Many researches have suggested fundamental changes to satisfy the safety requirements, including development of accident tolerant fuels (ATFs). The adoption of coating techniques is one of promising approaches for ATF systems because surface modification with a highly oxidation-resistant material can prevent hydrogen generation and cladding embrittlement. Compared to the development of a new cladding for the replacement of the current zirconium-based alloy cladding and new fuel forms instead of the current ceramic oxide fuels, the surface coating technique is cost-effective and easily applicable to the current LWR system with no significant design changes. Recently, a wide variety of oxidation-resistant materials have been proposed: iron-based alloys and SiC-based materials. Among them, chromium (Cr) is suggested as a coating material for fuel claddings because it is known for has oxidation-resistant characteristic. In order to assess the feasibility of coating techniques with an oxidation-resistant material, in this study chromium (Cr) film was deposited on a metal substrate via a physical vapor deposition (PVD) process. After preparing test specimens, pool boiling heat transfer experiments were carried out to investigate the boiling performance of both cases. Moreover, during a test, visualization works were conducted for a phenomenological understanding. In this study, Cr deposition on the SS316 surface was conducted using the sputtering process. Specifically, sophisticated surface characterization was performed with the wettability measurement and surface morphology analysis. Furthermore, the pool boiling heat transfer experiments were carried out to obtain the CHF value of the test heater. The major findings observed from this study can be summarized as follows. The surface wettability increased 77% after the sputtering deposition.

  1. Zirconium influence on microstructure of aluminide coatings deposited on nickel substrate by CVD method

    Indian Academy of Sciences (India)

    Jolanta Romanowska; Maryana Zagula-Yavorska; Jan Sieniawski

    2013-11-01

    Influence of Zr on the microstructure and phase characteristics of aluminide diffusion coatings deposited on the nickel substrate has been investigated in this study. The coatings with and without zirconium were deposited by CVD method. The cross-section chemical composition investigations revealed that during the coatings formation, there is an inward aluminum diffusion and outward nickel diffusion in both types of coatings (with and without zirconium), whereas zirconium is located far below the coating surface, at a depth of ∼17 m, between -NiAl phase and '-Ni3Al phase. XRD examinations showed that -NiAl, -NiAl and '-Ni3Al were the main components of the deposited coatings. -NiAl phase is on the surface of the coatings, whereas -NiAl and '-Ni3Al form deeper parts of the coatings. Zirconium is dissolved in NiAl on the border between -NiAl and '-Ni3Al.

  2. Yb2Si2O7 Environmental Barrier Coatings Deposited by Various Thermal Spray Techniques: A Preliminary Comparative Study

    Science.gov (United States)

    Bakan, Emine; Marcano, Diana; Zhou, Dapeng; Sohn, Yoo Jung; Mauer, Georg; Vaßen, Robert

    2017-06-01

    Dense, crack-free, uniform, and well-adhered environmental barrier coatings (EBCs) are required to enhance the environmental durability of silicon (Si)-based ceramic matrix composites in high pressure, high gas velocity combustion atmospheres. This paper represents an assessment of different thermal spray techniques for the deposition of Yb2Si2O7 EBCs. The Yb2Si2O7 coatings were deposited by means of atmospheric plasma spraying (APS), high-velocity oxygen fuel spraying (HVOF), suspension plasma spraying (SPS), and very low-pressure plasma spraying (VLPPS) techniques. The initial feedstock, as well as the deposited coatings, were characterized and compared in terms of their phase composition. The as-sprayed amorphous content, microstructure, and porosity of the coatings were further analyzed. Based on this preliminary investigation, the HVOF process stood out from the other techniques as it enabled the production of vertical crack-free coatings with higher crystallinity in comparison with the APS and SPS techniques in atmospheric conditions. Nevertheless, VLPPS was found to be the preferred process for the deposition of Yb2Si2O7 coatings with desired characteristics in a controlled-atmosphere chamber.

  3. Yb2Si2O7 Environmental Barrier Coatings Deposited by Various Thermal Spray Techniques: A Preliminary Comparative Study

    Science.gov (United States)

    Bakan, Emine; Marcano, Diana; Zhou, Dapeng; Sohn, Yoo Jung; Mauer, Georg; Vaßen, Robert

    2017-08-01

    Dense, crack-free, uniform, and well-adhered environmental barrier coatings (EBCs) are required to enhance the environmental durability of silicon (Si)-based ceramic matrix composites in high pressure, high gas velocity combustion atmospheres. This paper represents an assessment of different thermal spray techniques for the deposition of Yb2Si2O7 EBCs. The Yb2Si2O7 coatings were deposited by means of atmospheric plasma spraying (APS), high-velocity oxygen fuel spraying (HVOF), suspension plasma spraying (SPS), and very low-pressure plasma spraying (VLPPS) techniques. The initial feedstock, as well as the deposited coatings, were characterized and compared in terms of their phase composition. The as-sprayed amorphous content, microstructure, and porosity of the coatings were further analyzed. Based on this preliminary investigation, the HVOF process stood out from the other techniques as it enabled the production of vertical crack-free coatings with higher crystallinity in comparison with the APS and SPS techniques in atmospheric conditions. Nevertheless, VLPPS was found to be the preferred process for the deposition of Yb2Si2O7 coatings with desired characteristics in a controlled-atmosphere chamber.

  4. Microcrystalline coatings deposited by series double-pole electro-pulse discharge and its high-temperature oxidation behavior

    Institute of Scientific and Technical Information of China (English)

    徐强; 何业东; 王德仁; 齐慧滨; 李正伟; 高唯

    2002-01-01

    A new technique--series electro-pulse discharge (SEPD)--was developed as a surface coating process. In this process, both positive and negative poles of a pulse power were used as the depositing electrodes and the substrate alloy was used as an induction electrode. The physical process for such SEPD was tested by measuring the relationship between the discharge voltages and gaps in a pin-plate-pin system. Microcrystalline Ni20Cr alloy coatings and oxide- dispersed Ni20Cr alloy coatings were prepared on Ni20Cr alloy surface by using a vibrating SEPD device. Oxidation at 950℃ in ambient air showed that the microcrystalline Ni20Cr alloy coatings greatly improved the oxidation resistance of the substrate alloy. The addition of dispersed Y2O3 nano-particles into the microcrystalline coatings was found to further reduce the oxidation rate and enhance the oxide spallation resistance.

  5. CHARACTERIZATION OF YTTRIA AND MAGNESIA PARTIALLY STABILIZED ZIRCONIA BIOCOMPATIBLE COATINGS DEPOSITED BY PLASMA SPRAYING

    Directory of Open Access Journals (Sweden)

    Roşu R. A.

    2013-09-01

    Full Text Available Zirconia (ZrO2 is a biocompatible ceramic material which is successfully used in medicine to cover the metallic implants by various methods. In order to avoid the inconvenients related to structural changes which may appear because of the temperature treatment while depositing the zirconia layer over the metallic implant, certain oxides are added, the most used being Y2O3, MgO and CaO. This paper presents the experimental results regarding the deposition of yttria (Y2O3 and magnesia (MgO partially stabilized zirconia layers onto titanium alloy substrate by plasma spraying method. X ray diffraction investigations carried out both on the initial powders and the coatings evidenced the fact that during the thermal spraying process the structure has not been significantly modified, consisting primarily of zirconium oxide with tetragonal structure. Electronic microscopy analyses show that the coatings are dense, uniform and cracks-free. Adherence tests performed on samples whose thickness ranges between 160 and 220 μm showed that the highest value (23.5 MPa was obtained for the coating of ZrO2 - 8 wt. % Y2O3 with 160 μm thickness. The roughness values present an increasing tendency with increasing the coatings thickness.

  6. Microstructures and Key Properties of Mechanically Deposited Zn-Al Coatings

    Institute of Scientific and Technical Information of China (English)

    WANG Shengmin; HE Mingyi; ZHAO Xiaojun; PENG Zenghua; LIU Li

    2009-01-01

    Zn-Al coatings can provide protection to exposed steel parts in most environments. For this reason, the investigation of Zn-Al coatings become very popular in recent years. In order to study the microstructures and properties of mechanically deposited Zn-Al coating, zinc powders and aluminum powders were used to deposit Zn-Al coating by mechanical plating. The microstructures, phase constitutes and compositions of the coating were observed and analyzed with optical microscopy (OM), scanning electron microscopy(SEM), X-ray diffraction(XRD) and X-ray energy-dispersive spectroscopy(EDS). The results of observation show that the coating consists of almost spherically shaped zinc particles point contacting with each other; the coatings are composed of zinc particles, aluminum particles, interstice, and tin; extra fine zinc powders and some smaller interspersed inclusions are positioned in the interstices. Porosity and thickness of the coating were tested by ferroxyl test and magnetic method. The corrosion resistance of coatings was studied by neutral salt spraying test(NSS) , immersion test and electrochemical polarization. It is found that the thickness of the coating dose lacks uniformity, with an uneven thickness distribution and an average variation of approximately 2-5μm; the coating can afford cathodic protection to the steel substrate; the corrosion resistance of Zn-Al coatings is better than that of the mechanically plated zinc coatings with same thickness. These conclusions can be applied to improve anti-corrosion performance by mechanically deposit Zn-Al coatings.

  7. Inorganic-organic thin implant coatings deposited by lasers.

    Science.gov (United States)

    Sima, Felix; Davidson, Patricia M; Dentzer, Joseph; Gadiou, Roger; Pauthe, Emmanuel; Gallet, Olivier; Mihailescu, Ion N; Anselme, Karine

    2015-01-14

    The lifetime of bone implants inside the human body is directly related to their osseointegration. Ideally, future materials should be inspired by human tissues and provide the material structure-function relationship from which synthetic advanced biomimetic materials capable of replacing, repairing, or regenerating human tissues can be produced. This work describes the development of biomimetic thin coatings on titanium implants to improve implant osseointegration. The assembly of an inorganic-organic biomimetic structure by UV laser pulses is reported. The structure consists of a hydroxyapatite (HA) film grown onto a titanium substrate by pulsed-laser deposition (PLD) and activated by a top fibronectin (FN) coating deposited by matrix-assisted pulsed laser evaporation (MAPLE). A pulsed KrF* laser source (λ = 248 nm, τ = 25 ns) was employed at fluences of 7 and 0.7J/cm(2) for HA and FN transfer, respectively. Films approximately 1500 and 450 nm thick were obtained for HA and FN, respectively. A new cryogenic temperature-programmed desorption mass spectrometry analysis method was employed to accurately measure the quantity of immobilized protein. We determined that less than 7 μg FN per cm(2) HA surface is adequate to improve adhesion, spreading, and differentiation of osteoprogenitor cells. We believe that the proposed fabrication method opens the door to combining and immobilizing two or more inorganic and organic materials on a solid substrate in a well-defined manner. The flexibility of this method enables the synthesis of new hybrid materials by simply tailoring the irradiation conditions according to the thermo-physical properties of the starting materials.

  8. Recent progress in optical coating technology: low-voltage ion plating deposition

    Science.gov (United States)

    Guenther, Karl H.

    1990-08-01

    After fairly extensive discussions of the advantages and disadvantages of low energy and high energy ion beam bombardment of a growing film, we review briefly a number of experimental results obtained with various samples made with low voltage reactive ion plating deposition. The availability of a state-of-the-art high vacuum coating machine specifically equipped for this process is the foundation for a major leap toward achieving near-perfect optical coatings. The high density of ion plated thin films makes them impermeable to water vapor and corrosive solutions. This has been demonstrated with protected aluminum mirrors, polarizers, and infrared anti-reflection coatings. An indication of the high packing density is the substantially higher refractive index than that of comparable layers deposited with either conventional electron beam evaporation or ion assisted deposition. The spectral transmittance of multilayer stacks of oxide thin films is lower than expected from theoretical predictions which assume absorption-free dielectrics. The observed absorption is primarily of an interface nature rather than a volume effect and occurs predominantly in combinations of Ti02 and Si02 thin films.

  9. Preparation of rutile TiO(2) coating by thermal chemical vapor deposition for anticoking applications.

    Science.gov (United States)

    Tang, Shiyun; Wang, Jianli; Zhu, Quan; Chen, Yaoqiang; Li, Xiangyuan

    2014-10-08

    To inhibit the metal catalytic coking and improve the oxidation resistance of TiN coating, rutile TiO2 coating has been directly designed as an efficient anticoking coating for n-hexane pyrolysis. TiO2 coatings were prepared on the inner surface of SS304 tubes by a thermal CVD method under varied temperatures from 650 to 900 °C. The rutile TiO2 coating was obtained by annealing the as-deposited TiO2 coating, which is an alternative route for the deposition of rutile TiO2 coating. The morphology, elemental and phase composition of TiO2 coatings were characterized by SEM, EDX and XRD, respectively. The results show that deposition temperature of TiO2 coatings has a strong effect on the morphology and thickness of as-deposited TiO2 coatings. Fe, Cr and Ni at.% of the substrate gradually changes to 0 when the temperature is increased to 800 °C. The thickness of TiO2 coating is more than 6 μm and uniform by metalloscopy, and the films have a nonstoichiometric composition of Ti3O8 when the deposition temperature is above 800 °C. The anticoking tests show that the TiO2 coating at a deposition temperature of 800 °C is sufficiently thick to cover the cracks and gaps on the surface of blank substrate and cut off the catalytic coke growth effect of the metal substrate. The anticoking ratio of TiO2 coating corresponding to each 5 cm segments is above 65% and the average anticoking ratio of TiO2 coating is up to 76%. Thus, the TiO2 coating can provide a very good protective layer to prevent the substrate from severe coking efficiently.

  10. Broadband Reflective Coating Process for Large FUVOIR Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZeCoat Corporation will develop and demonstrate a set of revolutionary coating processes for making broadband reflective coatings suitable for very large mirrors (4+...

  11. Ion-beam-deposited boron carbide coatings for the extreme ultraviolet.

    Science.gov (United States)

    Blumenstock, G M; Keski-Kuha, R A

    1994-09-01

    The normal-incidence reflectance of ion-beam-deposited boron carbide thin films has been evaluated in the extreme ultraviolet (EUV) spectral region. High-reflectance coatings have been produced with reflectances greater than 30% between 67 and 121.6 nm. This high reflectance makes ion-beam-deposited boron carbide an attractive coating for EUV applications.

  12. Electrochemical deposition of coatings of highly entropic alloys from non-aqueous solutions

    Directory of Open Access Journals (Sweden)

    Jeníček V.

    2016-03-01

    Full Text Available The paper deals with electrochemical deposition of coatings of highly entropic alloys. These relatively new materials have been recently intensively studied. The paper describes the first results of electrochemical coating with highly entropic alloys by deposition from non-aqueous solutions. An electrochemical device was designed and coatings were deposited. The coatings were characterised with electronic microscopy scanning, atomic absorption spectrometry and X-ray diffraction methods and the combination of methods of thermic analysis of differential scanning calorimetry and thermogravimetry.

  13. Interface behavior study of WC92-Co8 coating produced by electrospark deposition

    Science.gov (United States)

    Ruijun, Wang; Yiyu, Qian; Jun, Liu

    2005-02-01

    WC92-Co8 coating produced by electrospark deposition effectively improves the surface performance of the substrate. The behavior of the interface between the WC92-Co8 coating and the substrate is studied in this paper. The high-melting-point WC92-Co8 was deposited onto the surface of Ti alloy, and the coating was usually more than 50 μm thick. The surface of the coating is mainly composed of TiC and W 2C besides a small amount of W, and its micro hardness reaches HV1129. The coating dramatically improves the performance of the substrate.

  14. New ceramic coating technique using laser spraying process

    Science.gov (United States)

    Tsukamoto, Koichi; Yanagisawa, Takeshi; Uchiyama, Futodhi; Obara, Akira; Okutomi, Mamoru; Kimura, Shinji; Yamada, Akimasa; Shen, Hong L.; Wang, Zhongcheng; Shen, Qinwo; Chatterjee, Udit; Bhar, Gopal C.

    1998-08-01

    A new ceramic coating technique using a CO2 laser has been developed. A high power density laser beam passes near the substrate. Coating materials are supplied by an extra-high accuracy powder supply device and pass across the laser beam. The coating materials are melted in the laser beam and deposited on the substrate surface. A YSZ (Yttria Stabilized Zirconia) layer and a LaCoO3 layer are made for high temperature solid oxide fuel cells. The crystal structures of the coated layers are the same as that of the original coating materials. Superconducting BPSCCO ceramic films are also made with this process. The films show super-conductivity with Tc at 81 K. The Jc of the specimen is 440 A/cm2 at 77 K. We can easily handle and arrange not only metal but also refractory materials. By adopting a multi-axis robot and a surface treatment laser technique, the laser spraying method described here makes it possible to produce highly functional and three dimensional parts of devices directly from raw powder materials. Thus the proposed method will open the path to an unexplored field of key production technology.

  15. Controllable preparation of a nano-hydroxyapatite coating on carbon fibers by electrochemical deposition and chemical treatment.

    Science.gov (United States)

    Wang, Xudong; Zhao, Xueni; Wang, Wanying; Zhang, Jing; Zhang, Li; He, Fuzhen; Yang, Jianjun

    2016-06-01

    A nano-hydroxyapatite (HA) coating with appropriate thickness and morphology similar to that of human bone tissue was directly prepared onto the surfaces of carbon fibers (CFs). A mixed solution of nitric acid, hydrochloric acid, sulfuric acid, and hydrogen peroxide (NHSH) was used in the preparation process. The coating was fabricated by combining NHSH treatment and electrochemical deposition (ECD). NHSH treatment is easy to operate, produces rapid reaction, and highly effective. This method was first used to induce the nucleation and growth of HA crystals on the CF surfaces. Numerous O-containing functional groups, such as hydroxyl (-OH) and carboxyl (-COOH) groups, were grafted onto the CF surfaces by NHSH treatment (NHSH-CFs); as such, the amounts of these groups on the functionalized CFs increased by nearly 8- and 12-fold, respectively, compared with those on untreated CFs. After treatment, the NHSH-CFs not only acquired larger specific surface areas but retained surfaces free from serious corrosion or breakage. Hence, NHSH-CFs are ideal depositional substrates of HA coating during ECD. ECD was successfully used to prepare a nano-rod-like HA coating on the NHSH-CF surfaces. The elemental composition, structure, and morphology of the HA coating were effectively controlled by adjusting various technological parameters, such as the current density, deposition time, and temperature. The average central diameter of HA crystals and the coating density increased with increasing deposition time. The average central diameter of most HA crystals on the NHSH-CFs varied from approximately 60 nm to 210 nm as the deposition time increased from 60 min to 180 min. Further studies on a possible deposition mechanism revealed that numerous O-containing functional groups on the NHSH-CF surfaces could associate with electrolyte ions (Ca(2+)) to form special chemical bonds. These bonds can induce HA coating deposition and improve the interfacial bonding strength between the HA

  16. PARTICLE COATING BY CHEMICAL VAPOR DEPOSITION IN A FLUIDI7ED BED REACTOR

    Institute of Scientific and Technical Information of China (English)

    Gregor; Czok; Joachim; Werther

    2005-01-01

    Aluminum coatings were created onto glass beads by chemical vapor deposition in a fluidized bed reactor at different temperatures. Nitrogen was enriched with Triisobutylaluminum (TIBA) vapor and the latter was thermally decomposed inside the fluidized bed to deposit the elemental aluminum. To ensure homogeneous coating on the bed material, the fluidizing conditions necessary to avoid agglomeration were investigated for a broad range of temperatures.The deposition reaction was modeled on the basis of a discrete particle simulation to gain insight into homogeneity and thickness of the coating throughout the bed material. In particular, the take-up of aluminum was traced for selected particles that exhibited a large mass of deposited aluminum.

  17. Decreased Fibroblast and Increased Osteoblast Functions on Ionic Plasma Deposited Nanostructured Ti Coatings

    Directory of Open Access Journals (Sweden)

    Storey Dan

    2007-01-01

    Full Text Available AbstractBioactive coatings are in high demand to control cellular functions for numerous medical devices. The objective of this in vitro study was to characterize for the first time fibroblast (fibrous scar tissue forming cells adhesion and proliferation on an important polymeric biomaterial (silicone coated with titanium using a novel ionic plasma deposition (IPD process. Fibroblasts are one of the first anchorage-dependent cells to arrive at an implant surface during the wound healing process. Persistent excessive functions of fibroblasts have been linked to detrimental fibrous tissue formation which may cause implant failure. The IPD process creates a surface-engineered nanostructure (with features usually below 100 nm by first using a vacuum to remove all contaminants, then guiding charged metallic ions or plasma to the surface of a medical device at ambient temperature. Results demonstrated that compared to currently used titanium and uncoated silicone, silicone coated with titanium using IPD significantly decreased fibroblast adhesion and proliferation. Results also showed competitively increased osteoblast (bone-forming cells over fibroblast adhesion on silicone coated with titanium; in contrast, osteoblast adhesion was not competitively increased over fibroblast adhesion on uncoated silicone or titanium controls. In this manner, this study strongly suggests that IPD should be further studied for biomaterial applications in which fibrous tissue encapsulation is undesirable (such as for orthopedic implants, cardiovascular components, etc..

  18. Preparation and characterization of boron nitride coatings on carbon fibers from borazine by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Li Junsheng, E-mail: charlesljs@163.com [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha, 410073 (China); Zhang Changrui; Li Bin [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha, 410073 (China)

    2011-06-15

    Boron nitride (BN) coatings were deposited on carbon fibers by chemical vapor deposition (CVD) using borazine as single source precursor. The deposited coatings were characterized by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The effect of temperatures on growth kinetics, morphology, composition and structure of the coatings was investigated. In the low temperature range of 900 deg. C-1000 deg. C, the growth rate increased with increasing temperature complying with Arrhenius law, and an apparent active energy of 72 kJ/mol was calculated. The coating surface was smooth and compact, and the coatings uniformly deposited on individual fibers of carbon fiber bundles. The growth was controlled by surface reaction. At 1000 deg. C, the deposition rate reached a maximum (2.5 {mu}m/h). At the same time, the limiting step of the growth translated to be mass-transportation. Above 1100 deg. C, the growth rate decreased drastically due to the occurrence of gas-phase nucleation. Moreover, the coating surface became loose and rough. Composition and structure examinations revealed that stoichiometric BN coatings with turbostratic structure were obtained below 1000 deg. C, while hexagonal BN coatings were deposited above 1100 deg. C. A penetration of carbon element from the fibers to the coatings was observed.

  19. Development of process technologies for improvement of electroless nickel coatings properties

    Science.gov (United States)

    Barba-Pingarrón, A.; Bolarín-Miró, A.; Sánchez – de Jesús, F.; Vargas-Mendoza, L.; Trujillo-Barragán, M.; Molera-Sola, P.; Hernandez-Gallegos, M. A.; Valdez-Navarro, R.

    2013-06-01

    This paper describes research and technology developments that enable to improve nickel electroless coating properties. This work deals with: (a) different methods in order to achieve Ni-P-Mo coatings. (b) Other development is related with coatings with addition of hard particles such as SiC, WC or Al2O3,(c) Electroless nickel deposits on PBT and austempered ductile iron (ADI). (d) In addition, nickel coatings were deposited on powder metallic pieces and finally, electroless nickel coatings, in conjunction with layers from thermal spray process were formed. Characterization of all coatings by means of optical microscopy, scanning electron microscopy, micro-hardness, wear and corrosion tests were carried out. Results indicate positive increment in both mechanical and electrochemical properties which enhance field applications in Mexican industry.

  20. High Throughput Atomic Layer Deposition Processes: High Pressure Operations, New Reactor Designs, and Novel Metal Processing

    Science.gov (United States)

    Mousa, MoatazBellah Mahmoud

    Atomic Layer Deposition (ALD) is a vapor phase nano-coating process that deposits very uniform and conformal thin film materials with sub-angstrom level thickness control on various substrates. These unique properties made ALD a platform technology for numerous products and applications. However, most of these applications are limited to the lab scale due to the low process throughput relative to the other deposition techniques, which hinders its industrial adoption. In addition to the low throughput, the process development for certain applications usually faces other obstacles, such as: a required new processing mode (e.g., batch vs continuous) or process conditions (e.g., low temperature), absence of an appropriate reactor design for a specific substrate and sometimes the lack of a suitable chemistry. This dissertation studies different aspects of ALD process development for prospect applications in the semiconductor, textiles, and battery industries, as well as novel organic-inorganic hybrid materials. The investigation of a high pressure, low temperature ALD process for metal oxides deposition using multiple process chemistry revealed the vital importance of the gas velocity over the substrate to achieve fast depositions at these challenging processing conditions. Also in this work, two unique high throughput ALD reactor designs are reported. The first is a continuous roll-to-roll ALD reactor for ultra-fast coatings on porous, flexible substrates with very high surface area. While the second reactor is an ALD delivery head that allows for in loco ALD coatings that can be executed under ambient conditions (even outdoors) on large surfaces while still maintaining very high deposition rates. As a proof of concept, part of a parked automobile window was coated using the ALD delivery head. Another process development shown herein is the improvement achieved in the selective synthesis of organic-inorganic materials using an ALD based process called sequential vapor

  1. Deposition of composite coatings from particle-particle and particle-yeast blends by convective-sedimentation assembly.

    Science.gov (United States)

    Jenkins, Jessica S; Flickinger, Michael C; Velev, Orlin D

    2012-08-15

    The structures resulting from convective-sedimentation assembly (CSA) of bimodal suspensions (4.1-10% solids) of strongly charged sulfate latex microspheres (zeta potential -55.9±1.8 mV at pH 8.0) and weakly charged Saccharomyces cerevisiae (zeta potential -18.7±0.71 mV at pH 8.0) on glass, polyester, polypropylene, and aluminum foil substrates was evaluated. This study shows how substrate wettability, suspension composition, particle size ratio and surface charge affect the deposition process and resulting coating microstructure (particle ordering and void space). Size ratio and charge influence deposition, convective mixing or demixing and relative particle locations. Substrate wettability and suspension composition influence coating microstructure by controlling suspension delivery and spreading across the substrate. S. cerevisiae behave like negatively-charged colloidal particles during CSA. CSA of particle-yeast blends result in open-packed structures (15-45% mean void space), instead of tightly packed coatings attainable with single component systems, confirming the existence of significant polymer particle-yeast interactions and formation of particle aggregates that disrupt coating microstructure during deposition. Further optimization of the process should allow void space reduction and deposition of cells plus adhesive polymer particles into tightly packed adhesive monolayer coatings for biosensors, biophotoabsorbers, energy applications, and highly reactive microbial absorbers. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Tribological and Corrosion Properties of Nickel/TiC Bilayered Coatings Produced by Electroless Deposition and PACVD

    Science.gov (United States)

    Shanaghi, Ali; Chu, Paul K.

    2016-11-01

    Ni/TiC bilayered coatings are deposited on hot-working steel (H11) by plasma-assisted chemical vapor deposition and electroless technique. The TiC layer is deposited at 490 °C using a gas mixture of TiCl4, CH4, H2, and Ar, and a dense nanostructured TiC coating with minimum excessive carbon phases and low chlorine concentration is produced. The effects of the Ni intermediate layer on the microstructure, tribology, and corrosion behavior of the nanostructured TiC coating are investigated. The friction coefficient of the Ni/TiC bilayered coating (Ni thickness = 4 µm) at 500 cycles is much smaller than that of the coating without the Ni intermediate layer. The smallest friction coefficient is about 0.2, and the hardness values of the Ni/TiC bilayered samples with three different Ni layer thicknesses of 2, 4, and 6 µm are 2534, 3070, and 2008 Hv, respectively. The wear mechanism of the Ni/TiC bilayered coatings is abrasive induced by plastic deformation and fatigue during the sliding process. The smaller groove width on the 4-µm electroless nickel-Ni3P/TiC bilayered coating correlates with the larger H/ E ratio and the 4-µm nickel/TiC bilayered sample shows the better wear resistance. The polarization resistance of the 6-µm electroless nickel-Ni3P/TiC coating in 0.05 M NaCl and 0.5 M H2SO4 increases by about 8 and 15 times, respectively. The Ni intermediate layer increases the toughness of the coating and adhesion between the hard coating and steel substrate thereby enhancing the tribological properties and corrosion resistance.

  3. Tribological and Corrosion Properties of Nickel/TiC Bilayered Coatings Produced by Electroless Deposition and PACVD

    Science.gov (United States)

    Shanaghi, Ali; Chu, Paul K.

    2016-10-01

    Ni/TiC bilayered coatings are deposited on hot-working steel (H11) by plasma-assisted chemical vapor deposition and electroless technique. The TiC layer is deposited at 490 °C using a gas mixture of TiCl4, CH4, H2, and Ar, and a dense nanostructured TiC coating with minimum excessive carbon phases and low chlorine concentration is produced. The effects of the Ni intermediate layer on the microstructure, tribology, and corrosion behavior of the nanostructured TiC coating are investigated. The friction coefficient of the Ni/TiC bilayered coating (Ni thickness = 4 µm) at 500 cycles is much smaller than that of the coating without the Ni intermediate layer. The smallest friction coefficient is about 0.2, and the hardness values of the Ni/TiC bilayered samples with three different Ni layer thicknesses of 2, 4, and 6 µm are 2534, 3070, and 2008 Hv, respectively. The wear mechanism of the Ni/TiC bilayered coatings is abrasive induced by plastic deformation and fatigue during the sliding process. The smaller groove width on the 4-µm electroless nickel-Ni3P/TiC bilayered coating correlates with the larger H/E ratio and the 4-µm nickel/TiC bilayered sample shows the better wear resistance. The polarization resistance of the 6-µm electroless nickel-Ni3P/TiC coating in 0.05 M NaCl and 0.5 M H2SO4 increases by about 8 and 15 times, respectively. The Ni intermediate layer increases the toughness of the coating and adhesion between the hard coating and steel substrate thereby enhancing the tribological properties and corrosion resistance.

  4. Hydroxyapatite/gelatin functionalized graphene oxide composite coatings deposited on TiO{sub 2} nanotube by electrochemical deposition for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yajing [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhang, Xuejiao [Medical Informatics, Hebei North University, Zhangjiakou 075000 (China); Mao, Huanhuan [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Huang, Yong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Ding, Qiongqiong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Pang, Xiaofeng, E-mail: xfpang@aliyun.com [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2015-02-28

    Highlights: • Graphene oxide cross-linked gelatin was firstly employed as reinforcement fillers in hydroxyapatite coatings by electrochemical deposition process on TiO{sub 2} nanotube arrays. • Gelatin functionalized graphene oxide induced the formation of hydroxyapatite coatings. • The success of gelatin and graphene oxide incorporation was evidenced with FTIR and XPS. • The synthesized composite coatings showed good biocompatibility and no adverse effect in cell culture tests. - Abstract: Graphene oxide cross-linked gelatin was employed as reinforcement fillers in hydroxyapatite coatings by electrochemical deposition process on TiO{sub 2} nanotube arrays (TNs). The TNs were grown on titanium by electrochemical anodization in hydrofluoric electrolyte using constant voltage. Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Field emission scanning electron microscopy equipped with energy dispersive X-ray analysis and biological studies were used to characterize the coatings. The corrosion resistance of the coatings was also investigated by electrochemical method in simulated body fluid solution.

  5. Synthesis of Colloidal ZnO Nanoparticles and Deposit of Thin Films by Spin Coating Technique

    Directory of Open Access Journals (Sweden)

    Jose Alberto Alvarado

    2013-01-01

    Full Text Available ZnO colloidal nanoparticles were synthesized, the average size of these nanoparticles is around 25 nm with hexagonal form. It was noted that stabilization depends directly on the purifying process; in this work we do not change the nature of the solution as a difference from Meulekamp's method, and we do not use any alkanes to remove the byproducts; only a centrifuge to remove those ones was used, thereby the stabilization increases up to 24 days. It is observed from the results that only three times of washing is enough to prevent the rapid aging process. The effect of annealing process on the composition, size, and geometrical shape of ZnO nanoparticles was studied in order to know whether the annealing process affects the crystallization and growth of the nanoparticles. After the synthesis, the colloidal nanoparticles were deposited by spin coating technique showing that the formed nanoparticles have no uniformly deposition pattern. But is possible to deposit those ones in glass substrates. A possible deposition process of the nanoparticles is proposed.

  6. Proliferation and differentiation of osteoblast-like MC3T3-E1 cells on biomimetically and electrolytically deposited calcium phosphate coatings

    NARCIS (Netherlands)

    Wang, Jiawei; Boer, de Jan; Groot, de Klaas

    2008-01-01

    Biomimetic and electrolytic deposition are versatile methods to prepare calcium phosphate coatings. In this article, we compared the effects of biomimetically deposited octacalcium phosphate and carbonate apatite coatings as well as electrolytically deposited carbonate apatite coating on the prolife

  7. NiTi intermetallic surface coatings by laser metal deposition for improving wear properties of Ti-6Al-4V substrates

    CSIR Research Space (South Africa)

    Mokgalaka, MN

    2014-03-01

    Full Text Available properties [9–13]. Stainless steel surfaces were coated with NiTi to enhance mechanical properties and corrosion resis- tance using different deposition techniques, including plasma Hindawi Publishing Corporation Advances in Materials Science... (PTA), plasma welding, plasma spray coating, and sputtering process, all with different degrees of success [14–17]. Ozel et al. [18] studied microstructure characteristic of NiTi coating on stainless steel by transferred arc process. When the arc...

  8. On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W. (PPF Industries, Pittsburgh, PA)

    2006-11-01

    Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are

  9. Crystallization Process of Heat-treated Amorphous Ni-P Alloy Coating

    Directory of Open Access Journals (Sweden)

    JIN Shi-wei

    2016-09-01

    Full Text Available Amorphous Ni-P alloy coatings were prepared on 45 carbon steel blocks using electrodeposition method. The thermal effect and quality change of Ni-P alloy coating under heating rate of 20℃/min were analyzed by differential scanning calorimetry (DSC and thermogravimetry (TG. Coatings were heat-treated at 300℃ and 400℃ for 0, 15, 30, 45, 60, 75min respectively, coating surface was characterized by scanning electron microscope (SEM, energy dispersive spectrometer (EDS, X-ray diffraction (XRD, microhardness tester. The result shows that the exothermic peak of Ni-P alloy coating appears at 284.8℃, coating quality and elemental composition are stable during the heat treatment. Crystallization process experiences a transformation of amorphous, metastable state NiP and Ni5P2, stable state Ni3P. The microhardness of coating can be improved remarkably after heat treatment, namely, the maximum value of heat-treated coating is 1036.56HV, which is nearly 2 times as hard as as-deposited coating. The corrosion resistance of heat-treated Ni-P alloy coating in NaCl solution is inferior to as-deposited coating, but they are both much better than 45 carbon steel substrate.

  10. HA coating on titanium with nanotubular anodized TiO2 intermediate layer via electrochemical deposition

    Institute of Scientific and Technical Information of China (English)

    WANG Yue-qin; TAO Jie; WANG Ling; HE Ping-ting; WANG Tao

    2008-01-01

    Hydroxyapatite (HA) coating has been prepared on titanium substrate through an electrochemical deposition approach.In order to improve the bonding strength between HA coating and Ti substrate,a well oriented and uniform titanium oxide nanotube array on the surface of titanium substrate was applied by means of anodic oxidation pre-treatment.Then the calcium hydrogen phosphate (CaHPO4-2H2O,DCPD) coating,as the precursor of hydroxyapatite coating,was electrodeposited on the anodized Ti.At the initial stage of electro-deposition,the DCPD crystals,in nanometer precipitates,are anchored in and between the tubes.With increasing the deposition time,the nanometer DCPD crystals are connected together to form a continuous coating on titanium oxide nanotube array.Finally,the DCPD coating is converted into hydroxyapatite one simply by being immersed in alkaline solution.

  11. Electrolytic deposition and corrosion resistance of Zn–Ni coatings obtained from sulphate-chloride bath

    Indian Academy of Sciences (India)

    Katarzyna Wykpis; Magdalena Popczyk; Antoni Budniok

    2011-07-01

    Zn–Ni coatings were deposited under galvanostatic conditions on steel substrate (OH18N9). The influence of current density of deposition on the surface morphology, chemical and phase composition was investigated. The corrosion resistance of Zn–Ni coatings obtained at current density 10–25 mA cm-2 are measured, and are compared with that of metallic cadmium coating. Structural investigations were performed by the X-ray diffraction (XRD) method. The surface morphology and chemical composition of deposited coatings were studied using a scanning electron microscope (JEOL JSM-6480) with EDS attachment. Studies of electrochemical corrosion resistance were carried out in the 5% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the ground of these research, the possibility of deposition of Zn–Ni coatings contained 24–26% at. Ni was exhibited. It was stated, that surface morphology, chemical and phase composition of these coatings are practically independent on current density of deposition. On the basis of electrochemical investigations it was found that corrosion resistance of these Zn–Ni coatings is also independent of current density. These coatings are more corrosion resistant in 5% NaCl solution than metallic cadmium. It was suggested that the Zn–Ni coating may be used as a substitute for toxic cadmium.

  12. Evaluation of chemical and structural properties of germanium-carbon coatings deposited by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jamali, Hossein, E-mail: h.jamali@mut-es.ac.ir; Mozafarinia, Reza; Eshaghi, Akbar

    2015-10-15

    Germanium-carbon coatings were deposited on silicon and glass substrates by plasma enhanced chemical vapor deposition (PECVD) using three different flow ratios of GeH{sub 4} and CH{sub 4} precursors. Elemental analysis, structural evaluation and microscopic investigation of coatings were performed using laser-induced breakdown spectroscopy (LIBS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), respectively. Based on the results, the coatings exhibited a homogeneous and dense structure free of pores with a very good adhesion to substrate. The structural evaluation revealed that the germanium-carbon coatings were a kind of a Ge-rich composite material containing the amorphous and crystalline germanium and amorphous carbon with the mixture of Ge–Ge, Ge–C, C–C, Ge–H and C–H bonds. The result suggested that the amorphisation of the coatings could be increased with raising CH{sub 4}:GeH{sub 4} flow rate ratio and subsequently increasing C amount incorporated into the coating. - Highlights: • Germanium-carbon coatings were prepared by PECVD technique. • The germanium-carbon coatings were a kind of composite material. • The amorphisation of the coatings were increased with raising CH{sub 4}:GeH{sub 4} flow ratio.

  13. Polyglycolic acid microneedles modified with inkjet-deposited antifungal coatings.

    Science.gov (United States)

    Boehm, Ryan D; Daniels, Justin; Stafslien, Shane; Nasir, Adnan; Lefebvre, Joe; Narayan, Roger J

    2015-03-02

    In this study, the authors examined use of piezoelectric inkjet printing to apply an antifungal agent, voriconazole, to the surfaces of biodegradable polyglycolic acid microneedles. Polyglycolic acid microneedles with sharp tips (average tip radius = 25 ± 3 μm) were prepared using a combination of injection molding and drawing lithography. The elastic modulus (9.9 ± 0.3 GPa) and hardness (588.2 ± 33.8 MPa) values of the polyglycolic acid material were determined using nanoindentation and were found to be suitable for use in transdermal drug delivery devices. Voriconazole was deposited onto the polyglycolic acid microneedles by means of piezoelectric inkjet printing. It should be noted that voriconazole has poor solubility in water; however, it is readily soluble in many organic solvents. Optical imaging, scanning electron microscopy, energy dispersive x-ray spectrometry, and Fourier transform infrared spectroscopy were utilized to examine the microneedle geometries and inkjet-deposited surface coatings. Furthermore, an in vitro agar plating study was performed on the unmodified, vehicle-modified, and voriconazole-modified microneedles. Unlike the unmodified and vehicle-modified microneedles, the voriconazole-modified microneedles showed antifungal activity against Candida albicans. The unmodified, vehicle-modified, and voriconazole-modified microneedles did not show activity against Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus. The results indicate that piezoelectric inkjet printing may be useful for loading transdermal drug delivery devices such as polyglycolic acid microneedles with antifungal pharmacologic agents and other pharmacologic agents with poor solubility in aqueous solutions.

  14. Evaluation of Chemical Coating Processes for AXAF

    Science.gov (United States)

    Engelhaupt, Darell; Ramsey, Brian; Mendrek, Mitchell

    1998-01-01

    The need existed at MSFC for the development and fabrication of radioisotope calibration sources of cadmium 109 and iron 55 isotopes. This was in urgent response to the AXA-F program. Several issues persisted in creating manufacturing difficulties for the supplier. In order to meet the MSFC requirements very stringent control needed to be maintained for the coating quality, specific activity and thickness. Due to the difficulties in providing the precisely controlled devices for testing, the delivery of the sources was seriously delayed. It became imperative that these fabrication issues be resolved to avoid further delays in this AXA-F observatory key component. The objectives are: 1) Research and provide expert advice on coating materials and procedures. 2) Research and recommend solutions to problems that have been experienced with the coating process. 3) Provide recommendations on the selection and preparation of substrates. 4) Provide consultation on the actual coating process including the results of the qualification and acceptance test programs. 5) Perform independent tests at UAH or MSFC as necessary.

  15. Tantalum Coating of Steel, Copper, Aluminum, and Titanium by Thermal Chemical Vapor Deposition (CVD)

    DEFF Research Database (Denmark)

    Christensen, Erik; Bjerrum, Niels

    1998-01-01

    Tantalum coatings ranging from 0.5 to 120 mm has been deposited by CVD at 625-1000 C using tantalum pentachloride as precursor. Deposition rates range from 1 to 80mm/h and an activation energy of 103 kJ/mole is calculated. Well adhering deposits has been obtained on stainless steel, carbon steels...

  16. Microstructural characterization and chemical compatibility of pulsed laser deposited yttria coatings on high density graphite

    Energy Technology Data Exchange (ETDEWEB)

    Sure, Jagadeesh [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mishra, Maneesha [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Tarini, M. [SRM University, Kattankulathur-603 203 (India); Shankar, A. Ravi; Krishna, Nanda Gopala [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Kuppusami, P. [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Mallika, C. [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mudali, U. Kamachi, E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India)

    2013-10-01

    Yttria coatings were deposited on high density (HD) graphite substrate by pulsed laser deposition method and subsequently annealing in vacuum at 1373 K was carried out to evaluate the thermal stability of the coatings. Yttria deposited on HD graphite samples were exposed to molten LiCl–KCl salt at 873 K for 3 h to evaluate the corrosion behavior of the coating for the purpose of pyrochemical reprocessing applications. The microstructure and the corrosion behavior of the yttria coating deposited on HD graphite in molten LiCl–KCl salt were evaluated by several characterization techniques. X-ray diffraction and Laser Raman patterns confirmed the presence of cubic phase of yttria in the coating. The surface morphology of yttria coating on HD graphite examined by scanning electron microscope and atomic force microscopy revealed the agglomeration of oxide particles and formation of clusters. After annealing at 1373 K, no appreciable grain growth of yttria particles could be observed. X-ray photoelectron spectroscopy analysis was carried out for elemental analysis before and after chemical compatibility test of the coated samples in molten LiCl–KCl salt to identify the corrosive elements present on the yttria coatings. The chemical compatibility and thermal stability of the yttria coating on HD graphite in molten LiCl–KCl salt medium have been established. - Highlights: • Y{sub 2}O{sub 3} coating was deposited on graphite by pulsed laser deposition method. • Chemical compatibility of Y{sub 2}O{sub 3} coating in LiCl–KCl salt at 873 K was studied. • Gibbs free energy change was positive for Y{sub 2}O{sub 3} reaction with Cl{sub 2}, U and UCl{sub 3}. • Y{sub 2}O{sub 3} coating exhibited better corrosion performance in molten LiCl–KCl salt.

  17. Fluidized bed coupled rotary reactor for nanoparticles coating via atomic layer deposition.

    Science.gov (United States)

    Duan, Chen-Long; Liu, Xiao; Shan, Bin; Chen, Rong

    2015-07-01

    A fluidized bed coupled rotary reactor has been designed for coating on nanoparticles (NPs) via atomic layer deposition. It consists of five major parts: reaction chamber, dosing and fluidizing section, pumping section, rotary manipulator components, as well as a double-layer cartridge for the storage of particles. In the deposition procedure, continuous fluidization of particles enlarges and homogenizes the void fraction in the particle bed, while rotation enhances the gas-solid interactions to stabilize fluidization. The particle cartridge presented here enables both the fluidization and rotation acting on the particle bed, demonstrated by the analysis of pressure drop. Moreover, enlarged interstitials and intense gas-solid contact under sufficient fluidizing velocity and proper rotation speed facilitate the precursor delivery throughout the particle bed and consequently provide a fast coating process. The cartridge can ensure precursors flowing through the particle bed exclusively to achieve high utilization without static exposure operation. By optimizing superficial gas velocities and rotation speeds, minimum pulse time for complete coating has been shortened in experiment, and in situ mass spectrometry showed the precursor usage can reach 90%. Inductively coupled plasma-optical emission spectroscopy results suggested a saturated growth of nanoscale Al2O3 films on spherical SiO2 NPs. Finally, the uniformity and composition of the shells were characterized by high angle annular dark field-transmission electron microscopy and energy dispersive X-ray spectroscopy.

  18. Fluidized bed coupled rotary reactor for nanoparticles coating via atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Chen-Long; Liu, Xiao; Chen, Rong, E-mail: rongchen@mail.hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China); Shan, Bin, E-mail: rongchen@mail.hust.edu.cn, E-mail: bshan@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China)

    2015-07-15

    A fluidized bed coupled rotary reactor has been designed for coating on nanoparticles (NPs) via atomic layer deposition. It consists of five major parts: reaction chamber, dosing and fluidizing section, pumping section, rotary manipulator components, as well as a double-layer cartridge for the storage of particles. In the deposition procedure, continuous fluidization of particles enlarges and homogenizes the void fraction in the particle bed, while rotation enhances the gas-solid interactions to stabilize fluidization. The particle cartridge presented here enables both the fluidization and rotation acting on the particle bed, demonstrated by the analysis of pressure drop. Moreover, enlarged interstitials and intense gas–solid contact under sufficient fluidizing velocity and proper rotation speed facilitate the precursor delivery throughout the particle bed and consequently provide a fast coating process. The cartridge can ensure precursors flowing through the particle bed exclusively to achieve high utilization without static exposure operation. By optimizing superficial gas velocities and rotation speeds, minimum pulse time for complete coating has been shortened in experiment, and in situ mass spectrometry showed the precursor usage can reach 90%. Inductively coupled plasma-optical emission spectroscopy results suggested a saturated growth of nanoscale Al{sub 2}O{sub 3} films on spherical SiO{sub 2} NPs. Finally, the uniformity and composition of the shells were characterized by high angle annular dark field-transmission electron microscopy and energy dispersive X-ray spectroscopy.

  19. Tribological characterization of zirconia coatings deposited on Ti6Al4V components for orthopedic applications.

    Science.gov (United States)

    Berni, M; Lopomo, N; Marchiori, G; Gambardella, A; Boi, M; Bianchi, M; Visani, A; Pavan, P; Russo, A; Marcacci, M

    2016-05-01

    overall difference of about 40% compared to the uncoated balls. In wet conditions, the friction values were found to be comparable between coated and uncoated materials, mainly due to a premature delamination of the coating. Scratch tests in wet showed in fact a reduction of the critical load required to a complete delamination due to a formation of blister, although no change or damage occurred at the coating during the soaking period. Although conditions of high values of contact pressure were considered, further analyses are however required to fully understand the behavior of YSZ coatings in wet environment and additional research on the deposition process will be mandatory in order to improve the coating tribological performance at long distances addressing orthopedic applications.

  20. A perspective of microplasma oxidation (MPO) and vapor deposition coatings in surface engineering of aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2004-01-01

    Over the past years, great achievements have been made in the development of coating technologies for surface improvement of aluminum alloys. Despite these achievements, the role in the market strongly depends on the ability of surface coating technology under technical and economic considerations to meet the increased demands for heavy tribological applications of aluminum alloys. Microplasma oxidation (MPO) technology has recently been studied as a novel and effective means to provide thick and hard ceramic coating with improved properties such as excellent load-bearing and wear resistance properties on aluminum alloys. The present work covers the evaluation of the performances of current single and duplex coatings combining MPO, physical vapor deposition (PVD), and plasma assisted chemical vapor deposition (PACVD) coatings on aluminum alloys. It suggests that the MPO coating is a promising candidate for design engineers to apply aluminum alloys to heavy load-bearing applications. The prospective future for the research on MPO coatings is introduced as well.

  1. Microanalyses of the hydroxyl-poly-calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thin calcium phosphate coatings on titanium alloy substrates wereprepared by Ar+ ion beam assisted deposition (IBAD) from hydroxyl-poly-calciumsodium phosphate (HPPA) target. The coatings were analyzed by XRD, FTIR, XPS.These analyses revealed that the as-deposited films were amorphous or no apparentcrystallinity. No distinct absorption band of the hydroxyl group was observed in FTIRspectra of the coatings but new absorption bands were presented for CO3-2. Thecalcium to phosphorous ratio of these coatings in different IBAD conditions variedfrom 0.46 to 3.36.

  2. Optimization of the deposition process of corrosion resistant Stellite 6 coatings produced by laser cladding; Optimizacion del proceso de aporte de recubrimientos anticorrosion de Stellite 6 producidos mediante plaqueado laser

    Energy Technology Data Exchange (ETDEWEB)

    Vicario, I.; Soriano, C.; Sanz, C.; Bayon, R.; Leunda, J.

    2009-07-01

    Laser cladding is one of the most efficient surface treatment technologies in the industry. It uses a laser heat source to deposit a thin layer of a desired material on a moving substrate, whose properties have to be improved, achieving a metallurgical bonding between them with low heat affected zone and low dilution, compared to other conventional technologies such as PTA, TIG welding or thermal Spraying. In this sense, it is remarkable that there are 3 main application fields for laser cladding technology: restoration of refurbishment of damaged parts, surface coating against corrosion or wear, and rapid proto typing. the present work described a study of the optimization of the laser cladding of Co based coatings (Diamalloy 4060NS) on medium carbon steel C45 (AISI 1945). After laser treatment, the surface of the substrate materials is improved in terms of resistance against corrosion; this confirmed in the analysis performed afterwards. it is also shown that the corrosion barrier properties have direct correlation with the laser cladding variables. (Author) 10 refs.

  3. Performance of a dual-process PVD/PS tungsten coating structure under deuterium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunmyung; Lee, Ho Jung; Kim, Sung Hwan [Department of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Song, Jae-Min [Department of Nuclear Engineering, Seoul National University, Seoul (Korea, Republic of); Jang, Changheui, E-mail: chjang@kaist.ac.kr [Department of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of)

    2016-11-01

    Highlights: • D{sup +} irradiation performance of a dual-process PVD/PS W coating was evaluated. • Low-energy plasmas exposure of 100 eV D{sup +} with 1.17 × 10{sup 21} D/s{sup −1} m{sup 2} flux was applied. • After D ion irradiation, flakes were observed on the surface of the simple PS coating. • While, sub-μm size protrusions were observed for dual-process PVD/PS W coating. • Height of D spike in depth profile was lower for dual-process PVD/PS W coating. - Abstract: A dual-process coating structure was developed on a graphite substrate to improve the performance of the coating structure under anticipated operating condition of fusion devices. A thin multilayer W/Mo coating (6 μm) was deposited by physical vapor deposition (PVD) method with a variation of Mo interlayer thickness on plasma spray (PS) W coating (160 μm) of a graphite substrate panel. The dual-process PVD/PS W coatings then were exposed to 3.08 × 10{sup 24} D m{sup −2} of 100 eV D ions with a flux of 1.71 × 10{sup 21} D m{sup −2} s{sup −1} in an electron cyclotron resonance (ECR) chamber. After irradiation, surface morphology and D depth profiles of the dual-process coating were analyzed and compared to those of the simple PS W coating. Both changes in surface morphology and D retention were strongly dependent on the microstructure of surface coating. Meanwhile, the existence of Mo interlayer seemed to have no significant effect on the retention of deuterium.

  4. Supersonic Plasma Spray Deposition of CoNiCrAlY Coatings on Ti-6Al-4V Alloy

    Science.gov (United States)

    Caliari, F. R.; Miranda, F. S.; Reis, D. A. P.; Essiptchouk, A. M.; Filho, G. P.

    2017-06-01

    Plasma spray is a versatile technology used for production of environmental and thermal barrier coatings, mainly in the aerospace, gas turbine, and automotive industries, with potential application in the renewable energy industry. New plasma spray technologies have been developed recently to produce high-quality coatings as an alternative to the costly low-pressure plasma-spray process. In this work, we studied the properties of as-sprayed CoNiCrAlY coatings deposited on Ti-6Al-4V substrate with smooth surface ( R a = 0.8 μm) by means of a plasma torch operating in supersonic regime at atmospheric pressure. The CoNiCrAlY coatings were evaluated in terms of their surface roughness, microstructure, instrumented indentation, and phase content. Static and dynamic depositions were investigated to examine their effect on coating characteristics. Results show that the substrate surface velocity has a major influence on the coating properties. The sprayed CoNiCrAlY coatings exhibit low roughness ( R a of 5.7 μm), low porosity (0.8%), excellent mechanical properties ( H it = 6.1 GPa, E it = 155 GPa), and elevated interface toughness (2.4 MPa m1/2).

  5. Reinforced Pulsed Laser-Deposited Hydroxyapatite Coating on 316 Stainless Steel

    Science.gov (United States)

    Bajpai, Shubhra; Gupta, Ankur; Pradhan, Siddhartha Kumar; Mandal, Tapendu; Balani, Kantesh

    2014-10-01

    Hydroxyapatite (HA) is a widely used bioceramic known for its chemical similarity with that of bone and teeth (Ca/P ratio of 1.67). But, owing to its extreme brittleness, α-Al2O3 is reinforced with HA and processed as a coating via pulsed laser deposition (PLD). Reinforcement of α-Al2O3 (50 wt.%) in HA via PLD on 316L steel substrate has shown modulus increase by 4% and hardness increase by 78%, and an improved adhesion strength of 14.2 N (improvement by 118%). Micro-scratching has shown an increase in the coefficient-of-friction from 0.05 (pure HA) to 0.17 (with 50 wt.% Al2O3) with enhancement in the crack propagation resistance (CPR) up to 4.5 times. Strong adherence of PLD HA-Al2O3 coatings (~4.5 times than that of HA coating) is attributed to efficient release of stored tensile strain energy (~17 × 10-3 J/m2) in HA-Al2O3 composites, making it a potential damage-tolerant bone-replacement surface coating.

  6. Structure property relationships of nitride superlattice hard coatings prepared by pulsed laser deposition

    Science.gov (United States)

    Patel, Nitin

    compared with that of the corresponding (111) isostructural cubic superlattices. Nanoindentation measurements revealed higher hardness values for the non-isostructural superlattices as compared to the isostructural coatings at higher periodicities and deposited under identical conditions. These types of non-isostructural superlattices are also highly suited for the commercial coatings where it is not possible to avoid higher periodicities due to the nature of commercial processes. Future directions to exploit these results in commercial coatings are addressed based on our observations.

  7. Kinetic Study of SiO2/S Coating Deposition by APCVD

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To alleviate catalytic coking on the inner surface of radiant tube for ethylene production in petrochemical plants,SiO2/S coatings were deposited on HP40 alloy specimens using dimethyldisulfide (DMDS) and tetraethoxysilane (TEOS) by atmospheric pressure chemical vapor deposition (APCVD). A two-dimension mathematical model was made to predict the growth rate of SiO2/S coating and to study the effects of deposition parameters on the deposition rate. The results show that the predicted deposition rate is in good agreement with the experimental one. The deposition rate mainly depends on the concentrations of precursors in the total gas flow, concentrations of intermediates on the deposition surface, total gas flow rate and deposition temperature. The weight of SiO2/S coating linearly increases with the deposition time. When the gas flow rate is below 0.3 m/s, the rate-limiting step of SiO2/S coating deposition is the diffusions of intermediates.However, the surface reactions of intermediates will be the rate-limiting step after the gas flow rate is above 0.3 m/s. When the deposition temperature is below 780℃, the rate-limiting step of SiO2/S coating deposition mainly depends on the surface reactions of intermediates. When the deposition temperature is above 780℃,the rate-limiting step depends on the diffusions of intermediates. The deposition rate increases with increasing the concentrations of the intermediates. However, when the partial pressures of the intermediates reach 8 Pa,the deposition rate keeps constant.

  8. Adhesion improvement of carbon-based coatings through a high ionization deposition technique

    Science.gov (United States)

    Broitman, E.; Hultman, L.

    2012-06-01

    The deposition of highly adherent carbon nitride (CNx) films using a pretreatment with two high power impulse magnetron sputtering (HIPIMS) power supplies in a master-slave configuration is reviewed. SKF3 (AISI 52100) steel substrates were pretreated in the environment of a high ionized Cr+Ar plasma in order to sputter clean the surface and implant Cr metal ions. CNx films were subsequently deposited at room temperature by DC magnetron sputtering from a high purity C target in a N2/Ar plasma discharge. All processing was done in an industrial-scale CemeCon CC800 coating system. A series of depositions were obtained with samples pretreated at different bias voltages (DC and pulsed). The adhesion of CNx films, evaluated by the Daimler-Benz Rockwell-C test, reaches strength quality HF1. Adhesion results are correlated to high resolution transmission electron microscopy observations confirming the formation of an optimal interfacial mixing layer of Cr and steel. The throwing power increase for HIPIMS coatings is associated to the higher ionization in the plasma discharge.

  9. Atomic layer deposited titanium dioxide coatings on KD-II silicon carbide fibers and their characterization

    Science.gov (United States)

    Cao, Shiyi; Wang, Jun; Wang, Hao

    2016-03-01

    To provide oxidation protection and/or to act as an interfacial coating, titanium oxide (TiO2) coatings were deposited on KD-II SiC fibers by employing atomic layer deposition (ALD) technique with tetrakis(dimethylamido)titanium (TDMAT) and water (H2O) as precursors. The average deposition rate was about 0.08 nm per cycle, and the prepared coatings were smooth, uniform and conformal, shielding the fibers entirely. The as-deposited coatings were amorphous regardless of the coating thickness, and changed to anatase and rutile crystal phase after annealing at 600 °C and 1000 °C, respectively. The oxidation measurement suggests that the TiO2 coating enhanced the oxidation resistance of SiC fibers obviously. SiC fibers coated with a 70-nm-thick TiO2 layer retained a relatively high tensile strength of 1.66 GPa even after exposition to air at 1400 °C for 1 h, and thick silica layer was not observed. In contrast, uncoated SiC fibers were oxidized dramatically through the same oxidation treatment, covered with a macro-cracked thick silica film, and the tensile strength was not measurable due to interfilament adhesion. The above results indicate that TiO2 films deposited by ALD are a promising oxidation resistance coating for SiC fibers.

  10. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  11. High-speed deposition of titanium carbide coatings by laser-assisted metal–organic CVD

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yansheng [Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Tu, Rong, E-mail: turong@whut.edu.cn [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Goto, Takashi [Institute for Materials Research, Tohoku University, Aoba-ku, 2-1-1 Katahira, Sendai 980-8577 (Japan)

    2013-08-01

    Graphical abstract: - Highlights: • A semiconductor laser was first used to prepare wide-area LCVD-TiC{sub x} coatings. • The effect of laser power for the deposition of TiC{sub x} coatings was discussed. • TiC{sub x} coatings showed a columnar cross section and a dense surface texture. • TiC{sub x} coatings had a 1–4 order lower laser density than those of previous reports. • This study gives the possibility of LCVD applying on the preparation of TiC{sub x} coating. - Abstract: A semiconductor laser-assisted chemical vapor deposition (LCVD) of titanium carbide (TiC{sub x}) coatings on Al{sub 2}O{sub 3} substrate using tetrakis (diethylamido) titanium (TDEAT) and C{sub 2}H{sub 2} as source materials were investigated. The influences of laser power (P{sub L}) and pre-heating temperature (T{sub pre}) on the microstructure and deposition rate of TiC{sub x} coatings were examined. Single phase of TiC{sub x} coatings were obtained at P{sub L} = 100–200 W. TiC{sub x} coatings had a cauliflower-like surface and columnar cross section. TiC{sub x} coatings in the present study had the highest R{sub dep} (54 μm/h) at a relative low T{sub dep} than those of conventional CVD-TiC{sub x} coatings. The highest volume deposition rate (V{sub dep}) of TiC{sub x} coatings was about 4.7 × 10{sup −12} m{sup 3} s{sup −1}, which had 3–10{sup 5} times larger deposition area and 1–4 order lower laser density than those of previous LCVD using CO{sub 2}, Nd:YAG and argon ion laser.

  12. Properties of the ZrO2MgO/MgZrO3NiCr/NiCr triple-layer thermal barrier coating deposited by the atmospheric plasma spray process

    OpenAIRE

    Mihailo R. Mrdak

    2016-01-01

    This paper presents the results of the examinations of TBC - ZrO2MgO / MgZrO3NiCr / NiCr thermal barrier layers deposited by the plasma spray process at the atmospheric pressure on substrates of Al alloys. In order to obtain the structural and mechanical properties of layers, which will provide a good heat and abrasion protection of the tail elevators of aircraft J-22 when firing '.Lightning' and 'Thunder' rockets, the deposition of three powder types was performed on 0.6 mm thick Al alloy su...

  13. Engineering Multifunctional Living Paints: Thin, Convectively-Assembled Biocomposite Coatings of Live Cells and Colloidal Latex Particles Deposited by Continuous Convective-Sedimentation Assembly

    Science.gov (United States)

    Jenkins, Jessica Shawn

    microstructure by controlling suspension delivery and spreading across the substrate. Microbes behave like colloidal particles during CSA, allowing for deposition of very thin stable biocomposite coatings of latex-live cell blends. CSA of particle-cell blends result in open-packed structures (15-45% mean void space), instead of tightly packed coatings attainable with single component systems, confirming the existence of significant polymer particle-cell interactions and formation of particle aggregates that disrupt coating microstructure during deposition. Tunable process parameters, such as particle concentration, fluid sonication, and fluid density, influence coating homogeneity when the meniscus is continuously supplied. Fluid density modification and fluid sonication affect particle sedimentation and distribution in the coating growth front whereas the suspended particle concentration strongly affects coating thickness, but has almost no effect on void space. Changing the suspension delivery mode (topside versus underside CCSA) yields disparate meniscus volumes and uneven particle delivery to the drying front, which enables control of the coating microstructure by varying the total number of particles available for deposition. The judicious combination of all these parameters will enable deposition of uniform, thin, latex-cell monolayers over areas on the order of tens of square centimeters or larger. To demonstrate the utility of biocomposite coatings, this dissertation investigated photoreactive coatings (artificial leaves) from suspensions of latex particles and nitrogen-limited Rps. palustris CGA009 or sulfur-limited C. reinhardtii CC-124. These coatings demonstrated stable, sustained (>90 hours) photohydrogen production under anoxygenic conditions. Nutrient reduction slows cell division, minimizing coating outgrowth, and promotes photohydrogen generation, improving coating reactivity. Scanning electron microscopy of microstructure revealed how coating reactivity can be

  14. Residual stress analysis of the thermal barrier coating system by considering the plasma spraying process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myung Jae; Lee, Byung Chai [KAIST, Daejeon (Korea, Republic of); Lim, Jang Gyun; Kim, Moon Ki [Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-06-15

    The residual stress is the key factor causing the reliability problem of thermal barrier coating (TBC). The failure of plasma spray coatings due to residual stresses is a serious and recurring problem of TBC. The difference of thermal expansion coefficient between the substrate and each coating combined with temperature evolution and temperature gradients during deposition process determine the residual stress for the whole TBC system. The magnitudes and distributions of the residual stresses are affected by deposition process and deposition characteristics. Most of FEA (finite element analysis) has been performed under the assumption that the multilayer coating system is stacked at once without considering the deposition process during plasma spraying. In this research, FEA for a coupled heat transfer and elastic-plastic thermal stress was performed to obtain the more detailed and reliable result of residual stress of the TBC system using the element activation/deactivation technique. The residual stress variation from the start of plasma spraying to cooling stage with room temperature was obtained systematically considering the deposition process. It can be used as reference data to improve the performance of TBC. In addition, the relationship between residual stress and coating conditions such as cooling rate and time is also examined thoroughly.

  15. Microstructure and Microhardness of TiC Particles Reinforced Coating In-situ Deposited on Titanium Alloy Surface by Electrospark Process%钛合金表面电火花原位沉积TiC颗粒强化层的组织与硬度

    Institute of Scientific and Technical Information of China (English)

    王忠英; 庞永平; 王坤

    2012-01-01

    以石墨为电极,采用电火花沉积工艺在BT20钛合金表面沉积了TiC颗粒得到了强化层,并对该强化层的组织和硬度进行了研究。结果表明:强化层分布不连续,厚度也不均匀,最厚处可达30μm,最薄处还不到10μm;强化层中TiC颗粒的分布不均匀,大量TiC聚集于强化层表面,内部很少,这使得强化层表面硬度达到了基体的5倍以上。%Taking the graphite as electrode, TiC particles were deposited on BT20 titanium alloy surface by eletrospark processing to form a reinforced coating. The mierostructure and microhardness of the coating were studied. The results show that the coating was discontinuous and uneven with the thickness of 10--30μa. The distribution of TiC particles in the reinforced coating was non-uniform, most of TiC existed on the reinforced coating surface and a little inside of the reinforced coating, which made the microhardness of the reinforced coating 4 times higher than that of the titanium alloy substrate.

  16. Long period gratings coated with hafnium oxide by plasma-enhanced atomic layer deposition for refractive index measurements.

    Science.gov (United States)

    Melo, Luis; Burton, Geoff; Kubik, Philip; Wild, Peter

    2016-04-04

    Long period gratings (LPGs) are coated with hafnium oxide using plasma-enhanced atomic layer deposition (PEALD) to increase the sensitivity of these devices to the refractive index of the surrounding medium. PEALD allows deposition at low temperatures which reduces thermal degradation of UV-written LPGs. Depositions targeting three different coating thicknesses are investigated: 30 nm, 50 nm and 70 nm. Coating thickness measurements taken by scanning electron microscopy of the optical fibers confirm deposition of uniform coatings. The performance of the coated LPGs shows that deposition of hafnium oxide on LPGs induces two-step transition behavior of the cladding modes.

  17. INKJET PRINTING OF ALUMOOXIDE SOL FOR DEPOSITION OF ANTIREFLECTING COATINGS

    Directory of Open Access Journals (Sweden)

    E. A. Eremeeva

    2017-01-01

    Full Text Available Subject of Research. This work describes for the first time the formation of antireflective coating on the base of boehmite phase of AlOOH with low refractive index (1.35 by inkjet printing on the nonporous substrate. This method gives the possibility to increase the contrast of colorful interfering images by 32% obtaining by inkjet printing of titanium dioxide sol. The usage of this technology enables to obtain patterns with wide viewing angle and makes them highly stable. Methods. Traditional sol-gel method with peptizing agents and heating for 90oC was applied for sol synthesis. Then the mixture was under sonic treatment for the obtaining of viscous sol. The viscosity was determined by Brookfield HA/HB viscometer, and the surface tension by Kyowa DY-700 tensiometer. Aluminum oxide ink was deposited on polished slides (26×76 mm2, Paul Marienfeld, Germany, over titanium oxide layer. To print titania ink, we use a desktop office printer Canon Pixma IP 2840 and Dimatix DMP-2831. The thickness of an inkjet AlOOH layer after drying in the air and removal of the solvents did not exceed 150 nm with an RI not less than 1.35 in the entire visible range. Results. The stable colloidal ink was obtained for the first time on the base of aluminum oxide matrix with neutral pH. The rheology was regulated by controlling parameters of sol-gel method in the system of aqueous titanium dioxide sol and by adding ethanol that affects the charge of double electrical layer of disperse phase. The controllable coalesce of drops enables to apply antireflection coating within the thickness accuracy of 10 nm. The morphology of particles and the topology of printed structures were analyzed by optical, scanning electron and atomic-force microscopes. Practical Relevance. We have proposed the approach to obtain colorful, interference patterns using two types of high refractive inks with different refractive indexes. The inkjet printing method opens new opportunities for

  18. Electroless deposition of nickel-boron coatings using low frequency ultrasonic agitation: Effect of ultrasonic frequency on the coatings.

    Science.gov (United States)

    Bonin, L; Bains, N; Vitry, V; Cobley, A J

    2017-01-30

    The effect of ultrasound on the properties of Nickel-Boron (NiB) coatings was investigated. NiB coatings were fabricated by electroless deposition using either ultrasonic or mechanical agitation. The deposition of Ni occurred in an aqueous bath containing a reducible metal salt (nickel chloride), reducing agent (sodium borohydride), complexing agent (ethylenediamine) and stabilizer (lead tungstate). Due to the instability of the borohydride in acidic, neutral and slightly alkaline media, pH was controlled at pH 12±1 in order to avoid destabilizing the bath. Deposition was performed in three different configurations: one with a classical mechanical agitation at 300rpm and the other two employing ultrasound at a frequency of either 20 or 35kHz. The microstructures of the electroless coatings were characterized by a combination of optical Microscopy and Scanning Electron Microscope (SEM). The chemistry of the coatings was determined by ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectrometry) after dissolution in aqua regia. The mechanical properties of the coatings were established by a combination of roughness measurements, Vickers microhardness and pin-on-disk tribology tests. Lastly, the corrosion properties were analysed by potentiodynamic polarization. The results showed that low frequency ultrasonic agitation could be used to produce coatings from an alkaline NiB bath and that the thickness of coatings obtained could be increased by over 50% compared to those produced using mechanical agitation. Although ultrasonic agitation produced a smoother coating and some alteration of the deposit morphology was observed, the mechanical and corrosion properties were very similar to those found when using mechanical agitation.

  19. Review on Sol-Gel Derived Coatings:Process, Techniques and Optical Applications

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Sol-gel process is one of the simplest techniques to manufacture thin films. The quality of the prepared films depends on the parameters of the sol-gel process and the used technique for deposition. A great variety of the sol-gel derived films have been prepared for different applications. We present a review on the sol-gel derived coatings. The description of the process is introduced in details. Different sol-gel deposition techniques are mentioned. The optical applications of the sol-gel derived coatings are reviewed.

  20. Research on Processes and Adhesion of Electroless Plating Ni-Cu-P Coating

    Institute of Scientific and Technical Information of China (English)

    HUANG Yan-bin; LIU Bo; ZHANG Ping; LIU De-gang; XU Xiao-li

    2004-01-01

    In order to improve the corrosion and wear resistance of the coatings of electroless plating Ni-Cu-P and broaden its application, an optimizing mathematical theory test has been applied in this research. The processing parameters have been optimized and some Ni-Cu-P coatings have been obtained with smooth and glittering appearance. At the same time,the composite complexants can prevent copper from depositing first and obtain coatings with strong adhesion. The porosity of Ni-Cu-P coating (20 μm) ranked class 9. The changing color time of the coating is more than 800 seconds with HNO3 dropthan 0.5 g/L. The surface appearance of deposition is typical cystiform cells by SEM,which rank close and neatly.

  1. Microstructure and tribological properties of Zr-based amorphous-nanocrystalline coatings deposited on the surface of titanium alloys by Electrospark Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Xiang; Tan, Yefa, E-mail: tanyefa7651@163.com; Zhou, Chunhua; Xu, Ting; Zhang, Zhongwei

    2015-11-30

    Highlights: • Zr-based amorphous-nanocrystalline coatings were well prepared on TC11 titanium alloys. • High glass forming ability of alloy system and high cooling rate of Electrospark Deposition process are beneficial for the generation of amorphous phase. • A model has been applied to investigate the generation of nanocrystalline phases in amorphous coating. • Excellent wear properties obtained due to nanocrystalline phases distributed in amorphous organization. - Abstract: In order to improve the wear resistance of titanium alloys, the Zr-based amorphous-nanocrystalline coatings were prepared by Electrospark Deposition (ESD) on the surface of TC11. The microstructure of the coatings was analyzed and the tribological behavior and mechanism of the coatings were investigated. The results show that the coating is mainly composed of amorphous phase Zr{sub 55}Cu{sub 30}Al{sub 10}Ni{sub 5} and distributed a large number of nano particles with the diameter between 2 nm and 4 nm such as CuZr{sub 3}, Ni{sub 2}Zr{sub 3}, NiZr{sub 2}, etc. The new alloy system made up of molten electrode material of Zr-based alloy and TC11 substrate has a large glass forming ability, which transforms to amorphous phase in the rapid heating and cooling ESD process. The long-range diffusions of atoms such as Zr and Cu in amorphous microstructure play an important role in nano nucleation growth. The coating is dense, uniform, bonding with TC11 substrate metallurgically. The thickness of the coating is from 55 μm to 60 μm and the average microhardness is 801.3 HV{sub 0.025}. The coating has good friction-reducing and anti-wear properties. The friction coefficient of the coating changes between 0.13 and 0.21 with small fluctuation, decreasing about 60% compared to that of TC11 substrate. And the wear resistance of the coating is increased by 57% than that of TC11 substrate. The main wear mechanism of the coating is micro-cutting wear accompanied with oxidation wear.

  2. Dry coating of solid dosage forms: an overview of processes and applications.

    Science.gov (United States)

    Foppoli, Anastasia Anna; Maroni, Alessandra; Cerea, Matteo; Zema, Lucia; Gazzaniga, Andrea

    2017-08-30

    Dry coating techniques enable manufacturing of coated solid dosage forms with no, or very limited, use of solvents. As a result, major drawbacks associated with both organic solvents and aqueous coating systems can be overcome, such as toxicological, environmental, and safety-related issues on the one hand as well as costly drying phases and impaired product stability on the other. The considerable advantages related to solventless coating has been prompting a strong research interest in this field of pharmaceutics. In the article, processes and applications relevant to techniques intended for dry coating are analyzed and reviewed. Based on the physical state of the coat-forming agents, liquid- and solid-based techniques are distinguished. The former include hot-melt coating and coating by photocuring, while the latter encompass press coating and powder coating. Moreover, solventless techniques, such as injection molding and three-dimensional printing by fused deposition modeling, which are not purposely conceived for coating, are also discussed in that they would open new perspectives in the manufacturing of coated-like dosage forms.

  3. Boron carbide (B{sub 4}C) coating. Deposition and testing

    Energy Technology Data Exchange (ETDEWEB)

    Azizov, E.; Barsuk, V. [Troitsk Institute for Innovation and Fusion Research (TRINITI), Moscow Region (Russian Federation); Begrambekov, L., E-mail: lbb@plasma.mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Buzhinsky, O. [Troitsk Institute for Innovation and Fusion Research (TRINITI), Moscow Region (Russian Federation); Evsin, A.; Gordeev, A.; Grunin, A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Klimov, N. [Troitsk Institute for Innovation and Fusion Research (TRINITI), Moscow Region (Russian Federation); Kurnaev, V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Mazul, I. [Federal State Unitary Interprise Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA Efremov), St-Peterburg (Russian Federation); Otroshchenko, V.; Putric, A. [Troitsk Institute for Innovation and Fusion Research (TRINITI), Moscow Region (Russian Federation); Sadovskiy, Ya.; Shigin, P.; Vergazov, S.; Zakharov, A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-08-15

    Boron carbide was proposed as a material of in-situ protecting coating for tungsten tiles of ITER divertor. To prove this concept the project including investigation of regimes of plasma deposition of B{sub 4}C coating on tungsten and tests of boron carbide layer in ITER-like is started recently. The paper contends the first results of the project. The results of B{sub 4}C coating irradiation by the plasma pulses of QSPU-T plasma accelerator are presented. The new device capable of B{sub 4}C film deposition on tungsten and testing of the films and materials with ITER-like heat loads and ion- and electron irradiation is described. The results of B{sub 4}C coating deposition and testing of both tungsten substrate and coating are shown and discussed.

  4. Effect of Rare Earth Elements on Depositing Rate of Nickel Alloy Brush Plating Coating

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of four kinds of rare earth elements on the depositing rate of Ni-based alloy brush plating coatings was investigated. The results indicate that all of the selected rare earth elements increase the depositing rate of Ni-based alloy coatings, and Sm increases the depositing rate most obviously. There is an optimum amount of rare earth addition in the plating solution. With the change of plating voltage to a certain extent, the results reveal no differences. The mechanism of the increase of the depositing rate was analyzed.

  5. Electroless Deposition of Composite Nickel-Phosphorous Coatings with Diamond Dispersoid

    Directory of Open Access Journals (Sweden)

    Petrova M.

    2016-06-01

    Full Text Available The composite Ni-P coating with diamond particles (D deposited on the flexible substrates of pressed polyethylene terephthalate material (PET was obtained, to be used in the development of efficient, flexible grinding and polishing tools. The optimal conditions of the hydrodynamic regime, deposition time and temperature were found. The influence of the concentration and size of the D particles (3/7 ÷ 225/300 μm on the coating thickness and number of co-deposited particles were studied. By Scanning Electron Microscopy (SEM images were defined the morphology of dispersion coatings and number of co-deposited particles in them, and Energy Dispersive Spectroscopy (EDS/INCA was used to determine the elemental chemical composition of the composite coatings.

  6. Osseointegration of porous titanium implants with and without electrochemically deposited DCPD coating in an ovine model

    National Research Council Canada - National Science Library

    Chen, Dong; Bertollo, Nicky; Lau, Abe; Taki, Naoya; Nishino, Tomofumi; Mishima, Hajime; Kawamura, Haruo; Walsh, William R

    2011-01-01

    .... In this study the effects of an electrochemically-deposited dicalcium phosphate dihydrate (DCPD) coating of a porous substrate on implant osseointegration was assessed using a standard uncemented implant fixation model in sheep...

  7. Formation of NiAl intermetallic coatings on stainless steel by a conventional duplex process

    Energy Technology Data Exchange (ETDEWEB)

    Ashrafizadeh, F.; Hajdaie, A.H.; Miraghaie, S. [Isfahan Univ. of Technology, Dept. of Materials Engineering, Isfahan (Iran, Islamic Republic of)

    2003-07-01

    Nickel-aluminide coatings were formed on 403 stainless steel samples by a duplex process incorporating electro-deposition and diffusion coating. Nickel was deposited by conventional electroplating on some specimens to appropriate thickness. The uncoated and nickel-coated samples were then aluminized by a powder pack method. Process parameters including pack composition, temperature, coating and annealing cycles were optimized in terms of the intermetallic phases produced in the near surface layers. The coatings and interface regions were characterized by optical and scanning electron microscopy, x-ray diffraction, glow discharge spectroscopy, micro-hardness measurements and pin-on-disc wear testing. Experimental results indicate that deposition of nickel on 403 steel before aluminizing produced two distinct layers of NiAl and FeAl on the surface and below that, respectively. The formation of these phases depends on the coating and annealing temperatures. The intermetallic phase NiAl on steel substrate acts as an alumina forming material to increase the life of aluminized layer. The intermetallic coatings produced by this duplex process had dense structure and excellent adhesion to the substrate; these are suitable candidates for high temperature applications of steel components under oxidation and hot corrosion conditions. (author)

  8. Microstructure and tribological properties of Zr-based amorphous-nanocrystalline coatings deposited on the surface of titanium alloys by Electrospark Deposition

    Science.gov (United States)

    Hong, Xiang; Tan, Yefa; Zhou, Chunhua; Xu, Ting; Zhang, Zhongwei

    2015-11-01

    In order to improve the wear resistance of titanium alloys, the Zr-based amorphous-nanocrystalline coatings were prepared by Electrospark Deposition (ESD) on the surface of TC11. The microstructure of the coatings was analyzed and the tribological behavior and mechanism of the coatings were investigated. The results show that the coating is mainly composed of amorphous phase Zr55Cu30Al10Ni5 and distributed a large number of nano particles with the diameter between 2 nm and 4 nm such as CuZr3, Ni2Zr3, NiZr2, etc. The new alloy system made up of molten electrode material of Zr-based alloy and TC11 substrate has a large glass forming ability, which transforms to amorphous phase in the rapid heating and cooling ESD process. The long-range diffusions of atoms such as Zr and Cu in amorphous microstructure play an important role in nano nucleation growth. The coating is dense, uniform, bonding with TC11 substrate metallurgically. The thickness of the coating is from 55 μm to 60 μm and the average microhardness is 801.3 HV0.025. The coating has good friction-reducing and anti-wear properties. The friction coefficient of the coating changes between 0.13 and 0.21 with small fluctuation, decreasing about 60% compared to that of TC11 substrate. And the wear resistance of the coating is increased by 57% than that of TC11 substrate. The main wear mechanism of the coating is micro-cutting wear accompanied with oxidation wear.

  9. Photocatalytic Properties of Doped TiO2 Coatings Deposited Using Reactive Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Parnia Navabpour

    2017-01-01

    Full Text Available Mechanically robust photocatalytic titanium oxide coatings can be deposited using reactive magnetron sputtering. In this article, we investigate the effect of doping on the activity of reactively sputtered TiO2. Silver, copper and stainless steel targets were used to co-deposit the dopants. The films were characterised using XRD, SEM and EDX. Adhesion and mechanical properties were evaluated using scratch testing and nano-indentation, respectively, and confirmed that the coatings had excellent adhesion to the stainless steel substrate. All coatings showed superhydrophilicity under UV irradiation. A methylene blue degradation test was used to assess their photocatalytic activity and showed all coatings to be photoactive to varying degrees, dependent upon the dopant, its concentration and the resulting coating structure. The results demonstrated that copper doping at low concentrations resulted in the coatings with the highest photocatalytic activity under both UV and fluorescent light irradiation.

  10. CrAlN coatings deposited by cathodic arc evaporation at different substrate bias

    Energy Technology Data Exchange (ETDEWEB)

    Romero, J. [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Avda. Diagonal 647, E-08028 Barcelona, Catalunya (Spain); Gomez, M.A. [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Avda. Diagonal 647, E-08028 Barcelona, Catalunya (Spain); Grupo de Corrosion y Proteccion, Universidad de Antioquia, A.A. 1226 Medellin (Colombia); Esteve, J. [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Avda. Diagonal 647, E-08028 Barcelona, Catalunya (Spain); Montala, F. [Tratamientos Termicos Carreras, TTC S.A., C/Doctor Almera 85, E-08205 Sabadell, Catalunya (Spain); Carreras, L. [Tratamientos Termicos Carreras, TTC S.A., C/Doctor Almera 85, E-08205 Sabadell, Catalunya (Spain); Grifol, M. [Tratamientos Termicos Carreras, TTC S.A., C/Doctor Almera 85, E-08205 Sabadell, Catalunya (Spain); Lousa, A. [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Avda. Diagonal 647, E-08028 Barcelona, Catalunya (Spain)]. E-mail: alousa@ub.edu

    2006-09-25

    CrAlN is a good candidate as an alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on hardened steel substrates by cathodic arc evaporation (CAE) from chromium-aluminum targets in a reactive nitrogen atmosphere at negative substrate bias between - 50 and - 400 V. The negative substrate bias has important effects on the deposition growth rate and crystalline structure. All our coatings presented hardness higher than conventional CrN coatings. The friction coefficient against alumina and tungsten carbide balls was around 0.6. The sliding wear coefficient of the CrAlN coatings was very low while an important wear was observed in the balls before a measurable wear were produced in the coatings. This effect was more pronounced as the negative substrate bias was increased.

  11. Microstructural characterization of electron beam-physical vapor deposition thermal barrier coatings through high-resolution computed microtomography

    Science.gov (United States)

    Kulkarni, Anand; Herman, Herbert; Decarlo, Francesco; Subramanian, Ramesh

    2004-07-01

    Thermal barrier coatings (TBCs), deposited using the electron beam-physical vapor deposition (EB-PVD) process, comprise a unique architecture of porosity capable of bridging the technological gap between insulation/life extension and prime reliance. The TBC microstructures consist of columnar structure, nucleated via vapor condensation, along with a high degree of intercolumnar porosity, thus providing enhanced stress relief on thermomechanical loading and also accommodating misfit stresses resulting from CTE mismatch. In this article, we report the characterization of these coatings using high-resolution synchrotron-based X-ray computed microtomography (XMT) at 1.3- µm resolution. Experiments focused on quantitative characterization/visualization of imperfections in these coatings and on the relative changes in microstructural features upon isothermal annealing. The influence of time/temperature of exposure was investigated and the results were correlated with elastic modulus.

  12. Characterization of microstructure and mechanical behavior of sputter deposited Ti-containing amorphous carbon coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Cao, D. M.; Meng, W. J.; Xu, J.; Tittsworth, R. C.; Rehn, L. E.; Baldo, P. M.; Doll, G. L.; Materials Science Division; Louisiana State Univ.; The Timken Company

    2001-12-03

    We report on the characterization of microstructure and mechanical properties of sputter deposited Ti-containing amorphous carbon (Ti-aC) coatings as a function of Ti composition. Ti-aC coatings have been deposited by unbalanced magnetron sputter deposition, in an industrial-scale four-target coating deposition system. The composition and microstructure of the Ti-aC coatings have been characterized in detail by combining the techniques of Rutherford backscattering spectrometry (RBS) and hydrogen elastic recoil detection (ERD), transmission electron microscopy (TEM), X-ray absorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. At Ti compositions <4at.%, Ti atoms dissolve in an amorphous carbon (a-C) matrix. The dissolution limit of Ti atoms in an a-C matrix is determined to be between 4 and 8 at.%. At Ti compositions >8 at.%, XANES and EXAFS data indicate that the average Ti atomic bonding environment in Ti-aC coatings resembles that in cubic B1-TiC, consistent with TEM observation of precipitation of TiC nanocrystallites in the a-C matrix. Beyond the Ti dissolution limit, the Ti-aC coatings are nanocomposites with nanocrystalline TiC clusters embedded in an a-C matrix. A large scale, quasi one-dimensional composition modulation in the Ti-aC coatings was observed due to the particular coating deposition geometry. Elastic stiffness and hardness of the Ti-aC coatings were measured by instrumented nanoindentation and found to vary systematically as a function of Ti composition. Unlubricated friction coefficient of Ti-aC coatings against WC-Co balls was found to increase as the Ti composition increases. As Ti composition increases, the overall mechanical behavior of the Ti-aC coatings becomes more TiC-like.

  13. Direct sputtering- and electro-deposition of gold coating onto the closed surface of ultralow-density carbon-hydrogen foam cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Jiaqiu; Yin, Jialing; Zhang, Hao; Yao, Mengqi; Hu, Wencheng, E-mail: huwc@uestc.edu.cn

    2016-12-15

    Highlights: • The surface pores of P(DVB/St) foam cylinder are sealed by CVD method. • Gold film was deposited on the surface of foam cylinder by magnetron sputtering. • Electroless plating was excluded in the present experiments. • The gold coatings were thickened through the electrodeposition process. - Abstract: This work aimed to fabricate a gold coating on the surface of ultralow-density carbon-hydrogen foam cylinder without electroless plating. Poly (divinylbenzene/styrene) foam cylinder was synthetized by high internal phase emulsion, and chemical vapor deposition polymerization approach was used to form a compact poly-p-xylylene film on the foam cylinder. Conducting gold thin films were directly deposited onto the poly-p-xylylene-modified foam cylinder by magnetron sputtering, and electrochemical deposition was adopted to thicken the gold coatings. The micro-structures and morphologies of poly (divinylbenzene/styrene) foam cylinder and gold coating were observed by field-emission scanning electron microscopy. The gold coating content was investigated by energy-dispersive X-ray. The thicknesses of poly-p-xylylene coating and sputtered gold thin-film were approximately 500 and 100 nm, respectively. After electrochemical deposition, the thickness of gold coating increased to 522 nm, and the gold coating achieved a compact and uniform structure.

  14. Surface modification of reverse osmosis desalination membranes by thin-film coatings deposited by initiated chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ozaydin-Ince, Gozde, E-mail: gozdeince@sabanciuniv.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Matin, Asif, E-mail: amatin@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khan, Zafarullah, E-mail: zukhan@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Zaidi, S.M. Javaid, E-mail: zaidismj@kfupm.edu.sa [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Gleason, Karen K., E-mail: kkgleasn@mit.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-07-31

    Thin-film polymeric reverse osmosis membranes, due to their high permeation rates and good salt rejection capabilities, are widely used for seawater desalination. However, these membranes are prone to biofouling, which affects their performance and efficiency. In this work, we report a method to modify the membrane surface without damaging the active layer or significantly affecting the performance of the membrane. Amphiphilic copolymer films of hydrophilic hydroxyethylmethacrylate and hydrophobic perfluorodecylacrylate (PFA) were synthesized and deposited on commercial RO membranes using an initiated chemical vapor deposition technique which is a polymer deposition technique that involves free-radical polymerization initiated by gas-phase radicals. Relevant surface characteristics such as hydrophilicity and roughness could be systematically controlled by varying the polymer chemistry. Increasing the hydrophobic PFA content in the films leads to an increase in the surface roughness and hydrophobicity. Furthermore, the surface morphology studies performed using the atomic force microscopy show that as the thickness of the coating increases average surface roughness increases. Using this knowledge, the coating thickness and chemistry were optimized to achieve high permeate flux and to reduce cell attachment. Results of the static bacterial adhesion tests show that the attachment of bacterial cells is significantly reduced on the coated membranes. - Highlights: • Thin films are deposited on reverse osmosis membranes. • Amphiphilic thin films are resistant to protein attachment. • The permeation performance of the membranes is not affected by the coating. • The thin film coatings delayed the biofouling.

  15. Functionalization and Area-Selective Deposition of Magnetic Carbon-Coated Iron Nanoparticles from Solution

    Directory of Open Access Journals (Sweden)

    Erika Widenkvist

    2011-01-01

    Full Text Available A route to area-selective deposition of carbon-coated iron nanoparticles, involving chemical modification of the surface of the particles, is described. Partial oxidative etching of the coating introduces carboxylic groups, which then are esterified. The functionalized particles can be selectively deposited on the Si areas of Si/SiO2 substrates by a simple dipping procedure. Nanoparticles and nanoassemblies have been analyzed using SEM, TEM, and XPS.

  16. Pyrolytic deposition of nanostructured titanium carbide coatings on the surface of multiwalled carbon nanotubes

    Science.gov (United States)

    Kremlev, K. V.; Ob"edkov, A. M.; Ketkov, S. Yu.; Kaverin, B. S.; Semenov, N. M.; Gusev, S. A.; Tatarskii, D. A.; Yunin, P. A.

    2016-05-01

    Nanostructured titanium carbide coatings have been deposited on the surface of multiwalled carbon nanotubes (MWCNTs) by the MOCVD method with bis(cyclopentadienyl)titanium dichloride precursor. The obtained TiC/MWCNT hybrid materials were characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. It is established that a TiC coating deposits onto the MWCNT surface with the formation of a core-shell (MWSNT-TiC) type structure.

  17. Electrophoretic deposition and reaction-bond sintering of Al2O3/Ti composite coating: evaluation of microstructure, phase and wear resistance

    Indian Academy of Sciences (India)

    M Mahmoudi; H Maleki-Ghaleh; M Kavanlouei

    2015-04-01

    In this study, Al2O3/Ti composite coating was deposited on TiAl6V4 substrate in various compositions using the electrophoretic deposition method. After the deposition, samples were dried at room temperature then the coated samples were sintered at 1050°C for 4 h. Scanning electron microscope and X-ray diffraction analysis were used to analyse the microstructure and morphology of coatings. The friction coefficient, wear (missing volume) and hardness of coatings have been studied in comparison with uncoated sample. The results demonstrate that the density of Al2O3/Ti composite coating increased considerably after heat treatment process. Moreover, wearing resistance of TiAl6V4 alloy escalated considerably, increasing its potential for application in orthopedic implants and artificial joints.

  18. Preparation of pyrite-coated sand grains for research on roll-type uranium deposits

    Science.gov (United States)

    Gent, Carol A.

    1977-01-01

    Ordinary quartz sand grains can be coated with pyrite for use in laboratory experiments on the genetic geochemistry of roll-type uranium deposits. The sand is first added to a ferric chloride solution. The slow addition of sodium hydroxide to the mixture gives the sand grains an iron oxide coating. This coating is then converted to pyrite by reaction with hydrogen sulfide, thus yielding a product suitable for experimental use.

  19. Dual Bath Electrodeposition of Alternate Multilayer Coatings of Zinc and Nickel Deposits

    Institute of Scientific and Technical Information of China (English)

    XINWen-li; FEIJing-yin; LIANGGuo-zheng

    2004-01-01

    The synthesis of zinc and nickel alternate multilayer coatings produced by successive deposition from dual baths containing a revised zinc sulphate electrolyte and a new developed nickel bath has been investigated. Smooth and uniform zinc-nickel compositionally modulated multilayered (CMM) coatings with different multilayer configurations were obtained. The surface and cross-sectional morphologies of samples were examined using scanning electron microscopy (SEM). Cross-sectional morphology showed the layered structure of the coatings clearly.

  20. Influence of deposition parameters on the structure and mechanical properties of nanocomposite coatings

    NARCIS (Netherlands)

    Galvan, D.; Pei, Y. T.; De Hosson, J. Th. M.

    2006-01-01

    Nanocomposite coatings based on TiC nanoparticles embedded in an amorphous hydrocarbon (a-C:H) matrix are deposited via reactive closed field unbalanced magnetron sputtering, employing Ti targets and acetylene gas as material precursors. The composition of the coatings is varied by changing the acet

  1. Advanced TiC/a-C : H nanocomposite coatings deposited by magnetron sputtering

    NARCIS (Netherlands)

    Pei, Y.T.; Galvan, D.; Hosson, J.Th.M. De; Strondl, C.

    2006-01-01

    TiC/a-C:H nanocomposite coatings have been deposited by magnetron Sputtering. They consist of 2-5 nm TiC nanocrystallites embedded in the amorphous hydrocarbon (a-C:H) matrix. A transition from a Columnar to a glassy microstructure has been observed in the nanocomposite coatings with increasing subs

  2. Microstructure of Ti6Al4V reinforced by coating W particles through laser metal deposition

    CSIR Research Space (South Africa)

    Ndou, N

    2016-10-01

    Full Text Available -0958 (Print); ISSN: 2078-0966 (Online) WCECS 2016 [5] S. A. Tsipas, M. Vázquez-alcázar, E. M. R. Navas, & E. Gordo, Boride coatings obtained by pack cementation deposited on powder metallurgy and wrought Ti and Ti–6Al–4V. Surface and Coatings Technology...

  3. Deformation Behavior of Nanostructured Ceramic Coatings Deposited by Thermal Plasma Spray

    Institute of Scientific and Technical Information of China (English)

    Xianliang JIANG; Eric Jordan; Leon Shaw; Maurice Gell

    2004-01-01

    Al2O3-13 wt pct TiO2 coating deposited by direct current plasma spray consists of nanostructured region and microlamellae. Bend test shows that the ceramic coating can sustain some deformation without sudden failure. The deformation is achieved through the movement of nano-particles in the nanostructured region under tensile stress.

  4. Synthesis of photocatalytic TiO2 nano-coatings by supersonic cluster beam deposition

    NARCIS (Netherlands)

    Fraters, B.D.; Cavaliere, E; Mul, G.; Gavioli, L.

    2014-01-01

    In this paper we report on the photocatalytic behavior in gas phase propane oxidation of well-defined TiO2 nanoparticle (NP) coatings prepared via Supersonic Cluster Beam Deposition (SCBD) on Si-wafers and quartz substrates. The temperature dependent crystal phase of the coatings was analyzed by Ram

  5. Crack resistance of pvd coatings : Influence of surface treatment prior to deposition

    NARCIS (Netherlands)

    Zoestbergen, E; De Hosson, JTM

    2002-01-01

    The crack resistance of three different PVD coatings, TiN, Ti(C,N), and a multilayer system of alternating TiN and TiAlN, have been investigated. The three coating systems were deposited onto substrates with a different surface roughness to study the influence of this pretreatment on the crack resis

  6. State of residual stress in laser-deposited ceramic composite coatings on aluminum alloys

    NARCIS (Netherlands)

    Kadolkar, P. B.; Watkins, T. R.; De Hosson, J. Th. M.; Kooi, B. J.; Dahotre, N. B.

    2007-01-01

    The nature and magnitude of the residual stresses within laser-deposited titanium carbide (TiC) coatings on 2024 and 6061 aluminum (Al) alloys were investigated. Macro- and micro-stresses within the coatings were determined using an X-ray diffraction method. Owing to increased debonding between the

  7. BN coatings deposition by magnetron sputtering of B and BN targets in electron beam generated plasma

    Science.gov (United States)

    Kamenetskikh, A. S.; Gavrilov, N. V.; Koryakova, O. V.; Cholakh, S. O.

    2017-05-01

    Boron nitride coatings were deposited by reactive pulsed magnetron sputtering of B and BN targets (50 kHz, 10 µs for B; 13.56 MHz for BN) at 2-20 mA/cm2 ion current density on the substrate. The effect of electron beam generated plasma on characteristics of magnetron discharge and phase composition of coatings was studied.

  8. Microstructural characterization of Co-based coating deposited by low power pulse laser cladding

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Ocelik, V.; De Hosson, J. Th. M.

    A detailed microstructural study of Stellite 6 coating deposited on a low carbon ferritic steel substrate using preplaced powder method and low power Nd:YAG pulse laser is performed. The grain structure and solidification texture of the coating are investigated by orientation imaging microscopy

  9. Microstructural characterization of Co-based coating deposited by low power pulse laser cladding

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Ocelik, V.; De Hosson, J. Th. M.

    2013-01-01

    A detailed microstructural study of Stellite 6 coating deposited on a low carbon ferritic steel substrate using preplaced powder method and low power Nd:YAG pulse laser is performed. The grain structure and solidification texture of the coating are investigated by orientation imaging microscopy (OIM

  10. Process optimization of ultrasonic spray coating of polymer films.

    Science.gov (United States)

    Bose, Sanjukta; Keller, Stephan S; Alstrøm, Tommy S; Boisen, Anja; Almdal, Kristoffer

    2013-06-11

    In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 μm) and low roughness compared to the film thickness. The coatings are characterized with respect to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model is developed for statistical analysis which identifies the distance between nozzle and substrate as the most significant parameter. Depending on the drying of the sprayed droplets on the substrate, we define two broad regimes, "dry" and "wet". The optimum condition of spraying lies in a narrow window between these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating with poly (D,L-lactide) (PDLLA). The results confirm the processing knowledge obtained with PVP and indicate that the observed trends are identical for spraying of other polymer films.

  11. Deposition of hybrid organic-inorganic composite coatings using an atmospheric plasma jet system.

    Science.gov (United States)

    Dembele, Amidou; Rahman, Mahfujur; Reid, Ian; Twomey, Barry; MacElroy, J M Don; Dowling, Denis P

    2011-10-01

    The objective of this study is to investigate the influence of alcohol addition on the incorporation of metal oxide nanoparticles into nm thick siloxane coatings. Titanium oxide (TiO2) nanoparticles with diameters of 30-80 nm were incorporated into an atmospheric plasma deposited tetramethylorthosilicate (TMOS) siloxane coating. The TMOS/TiO2 coating was deposited using the atmospheric plasma jet system known as PlasmaStream. In this system the liquid precursor/nanoparticle mixture is nebulised into the plasma. It was observed that prior to being nebulised the TiO2 particles agglomerated and settled over time in the TMOS/TiO2 mixture. In order to obtain a more stable nanoparticle/TMOS suspension the addition of the alcohols methanol, octanol and pentanol to this mixture was investigated. The addition of each of these alcohols was found to stabilise the nanoparticle suspension. The effect of the alcohol was therefore assessed with respect to the properties of the deposited coatings. It was observed that coatings deposited from TMOS/TiO2, with and without the addition of methanol were broadly similar. In contrast the coatings deposited with octanol and pentanol addition to the TMOS/TiO2 mixture were significantly thicker, for a given set of deposition parameters and were also more homogeneous. This would indicate that the alcohol precursor was incorporated into the plasma polymerised siloxane. The incorporation of the organic functionality from the alcohols was confirmed from FTIR spectra of the coatings. The difference in behaviour with alcohol type is likely to be due to the lower boiling point of methanol (65 degrees C), which is lower than the maximum plasma temperature measured at the jet orifice (77 degrees C). This temperature is significantly lower than the 196 degrees C and 136 degrees C boiling points of octanol and pentanol respectively. The friction of the coatings was determined using the Pin-on-disc technique. The more organic coatings deposited with

  12. Sprayed and Spin-Coated Multilayer Antireflection Coating Films for Nonvacuum Processed Crystalline Silicon Solar Cells

    OpenAIRE

    Abdullah Uzum; Masashi Kuriyama; Hiroyuki Kanda; Yutaka Kimura; Kenji Tanimoto; Hidehito Fukui; Taichiro Izumi; Tomitaro Harada; Seigo Ito

    2017-01-01

    Using the simple and cost-effective methods, spin-coated ZrO2-polymer composite/spray-deposited TiO2-compact multilayer antireflection coating film was introduced. With a single TiO2-compact film on the surface of a crystalline silicon wafer, 5.3% average reflectance (the reflectance average between the wavelengths of 300 nm and 1100 nm) was observed. Reflectance decreased further down to 3.3% after forming spin-coated ZrO2 on the spray-deposited TiO2-compact film. Silicon solar cells were fa...

  13. Electrochemical deposition and evaluation of electrically conductive polymer coating on biodegradable magnesium implants for neural applications.

    Science.gov (United States)

    Sebaa, Meriam A; Dhillon, Shan; Liu, Huinan

    2013-02-01

    In an attempt to develop biodegradable, mechanically strong, biocompatible, and conductive nerve guidance conduits, pure magnesium (Mg) was used as the biodegradable substrate material to provide strength while the conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) was used as a conductive coating material to control Mg degradation and improve cytocompatibility of Mg substrates. This study explored a series of electrochemical deposition conditions to produce a uniform, consistent PEDOT coating on large three-dimensional Mg samples. A concentration of 1 M 3,4-ethylenedioxythiophene in ionic liquid was sufficient for coating Mg samples with a size of 5 × 5 × 0.25 mm. Both cyclic voltammetry (CV) and chronoamperometry coating methods produced adequate coverage and uniform PEDOT coating. Low-cost stainless steel and copper electrodes can be used to deposit PEDOT coatings as effectively as platinum and silver/silver chloride electrodes. Five cycles of CV with the potential ranging from -0.5 to 2.0 V for 200 s per cycle were used to produce consistent coatings for further evaluation. Scanning electron micrographs showed the micro-porous structure of PEDOT coatings. Energy dispersive X-ray spectroscopy showed the peaks of sulfur, carbon, and oxygen, indicating sufficient PEDOT coating. Adhesion strength of the coating was measured using the tape test following the ASTM-D 3359 standard. The adhesion strength of PEDOT coating was within the classifications of 3B to 4B. Tafel tests of the PEDOT coated Mg showed a corrosion current (I(CORR)) of 6.14 × 10(-5) A as compared with I(CORR) of 9.08 × 10(-4) A for non-coated Mg. The calculated corrosion rate for the PEDOT coated Mg was 2.64 mm/year, much slower than 38.98 mm/year for the non-coated Mg.

  14. Novel bioactive antimicrobial lignin containing coatings on titanium obtained by electrophoretic deposition.

    Science.gov (United States)

    Erakovic, Sanja; Jankovic, Ana; Tsui, Gary C P; Tang, Chak-Yin; Miskovic-Stankovic, Vesna; Stevanovic, Tatjana

    2014-07-11

    Hydroxyapatite (HAP) is the most suitable biocompatible material for bone implant coatings; its brittleness, however, is a major obstacle, and the reason why research focuses on creating composites with biopolymers. Organosolv lignin (Lig) is used for the production of composite coatings, and these composites were examined in this study. Titanium substrate is a key biomedical material due to its well-known properties, but infections of the implantation site still impose a serious threat. One approach to prevent infection is to improve antimicrobial properties of the coating material. Silver doped hydroxyapatite (Ag/HAP) and HAP coatings on titanium were obtained by an electrophoretic deposition method in order to control deposited coating mass and morphology by varying applied voltage and deposition time. The effect of lignin on microstructure, morphology and thermal behavior of biocomposite coatings was investigated. The results showed that higher lignin concentrations protect the HAP lattice during sintering, improving coating stability. The corrosion stability was evaluated in simulated body fluid (SBF) at 37 °C. Newly formed plate-shaped carbonate-HAP was detected, indicating enhanced bioactive performance. The antimicrobial efficiency of Ag/HAP/Lig was confirmed by its higher reduction of bacteria Staphylococcus aureus TL (S. aureus TL) than of HAP/Lig coating. Cytotoxicity assay revealed that both coatings can be classified as non-toxic against healthy immunocompetent peripheral blood mononuclear cells (PBMC).

  15. Novel Bioactive Antimicrobial Lignin Containing Coatings on Titanium Obtained by Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Sanja Erakovic

    2014-07-01

    Full Text Available Hydroxyapatite (HAP is the most suitable biocompatible material for bone implant coatings; its brittleness, however, is a major obstacle, and the reason why research focuses on creating composites with biopolymers. Organosolv lignin (Lig is used for the production of composite coatings, and these composites were examined in this study. Titanium substrate is a key biomedical material due to its well-known properties, but infections of the implantation site still impose a serious threat. One approach to prevent infection is to improve antimicrobial properties of the coating material. Silver doped hydroxyapatite (Ag/HAP and HAP coatings on titanium were obtained by an electrophoretic deposition method in order to control deposited coating mass and morphology by varying applied voltage and deposition time. The effect of lignin on microstructure, morphology and thermal behavior of biocomposite coatings was investigated. The results showed that higher lignin concentrations protect the HAP lattice during sintering, improving coating stability. The corrosion stability was evaluated in simulated body fluid (SBF at 37 °C. Newly formed plate-shaped carbonate-HAP was detected, indicating enhanced bioactive performance. The antimicrobial efficiency of Ag/HAP/Lig was confirmed by its higher reduction of bacteria Staphylococcus aureus TL (S. aureus TL than of HAP/Lig coating. Cytotoxicity assay revealed that both coatings can be classified as non-toxic against healthy immunocompetent peripheral blood mononuclear cells (PBMC.

  16. Thick CrN/NbN multilayer coating deposited by cathodic arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Juliano Avelar; Tschiptschin, Andre Paulo; Souza, Roberto Martins, E-mail: antschip@usp.br [Universidade de Sao Paulo (USP), SP (Brazil); Lima, Nelson Batista de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-01-15

    The production of tribological nanoscale multilayer CrN/NbN coatings up to 6 μm thick by Sputtering/HIPIMS has been reported in literature. However, high demanding applications, such as internal combustion engine parts, need thicker coatings (>30 μm). The production of such parts by sputtering would be economically restrictive due to low deposition rates. In this work, nanoscale multilayer CrN/NbN coatings were produced in a high-deposition rate, industrial-size, Cathodic Arc Physical Vapor Deposition (ARC-PVD) chamber, containing three cathodes in alternate positions (Cr/ Nb/Cr). Four 30 μm thick NbN/CrN multilayer coatings with different periodicities (20, 10, 7.5 and 4 nm) were produced. The coatings were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The multilayer coating system was composed of alternate cubic rock salt CrN and NbN layers, coherently strained due to lattice mismatch. The film grew with columnar morphology through the entire stratified structure. The periodicities adopted were maintained throughout the entire coating. The 20 nm periodicity coating showed separate NbN and CrN peaks in the XRD patterns, while for the lower periodicity (≤10nm) coatings, just one intermediate lattice (d-spacing) was detected. An almost linear increase of hardness with decreasing bilayer period indicates that interfacial effects can dominate the hardening mechanisms. (author)

  17. The Study of Selected Properties of Ti EB PVD Coating Deposited Onto Inner Tube Surface at Low Temperature

    Directory of Open Access Journals (Sweden)

    Kottfer D.

    2016-03-01

    Full Text Available This study investigates the selected properties of the thin Ti coating applied by activated evaporation EB PVD technique. This technique was used for the deposition of Ti thin coating onto inner surface of OKhN3 MFA steel tubes. Deposition process was carried out at temperature 200°C. Conventional type of coatings - monolayer Ti - was analyzed by standard techniques for surface status and quality assessment - coating thickness, chemical composition by EDX analysis, adhesion, hardness, roughness, and growth direction of columns at room temperature. Ti monolayer achieved roughness Ra equal from 0.42 μm to 0.47 μm. The resulting hardness was from 2 GPa to 8.5 GPa depending on the sample location inside the vacuum chamber. Placing of the coated surface also affected the direction of grain growth of Ti coating columns. The angles α of grain growth were found to be from 40° to 60°. Angle α increased two to three times more than the incidence angle β (from 12° to 28° of evaporated Ti particles. Values of the adhesion measured along the Ti growth direction were mostly higher (up to 10% or the same as those measured perpendicular to it.

  18. The Influence of Modes of Deposition of Coatings on the Corrosion Resistance of Welded Joints of Steels in Acidic Media;

    Science.gov (United States)

    Saraev, Yu N.; Bezborodov, V. P.; Selivanov, Y. V.

    2016-08-01

    In this work, effect of welding on corrosion of welded joints of austenitic steel 12KH18N10T. It is shown that the use of pulsed - arc welding steel 12KH18N10T allows you to create a protective coating with dispersed structure with less thermal impact on the zone of the welded joint. Coating is of such structure allows 1.5 to 6 times to reduce the corrosion rate of welded joints of steel 12KH18N10T in active chemical environments. Pulse the process of deposition of coatings on welded joint of steels can be effectively used for the protection against corrosion in the repair of equipment of chemical industry. The results obtained can be recommended for use when welding a protective corrosion - resistant coatings on working surfaces of equipment of chemical productions.

  19. Porous-Al2O3 thermal barrier coatings with dispersed Pt particles prepared by cathode plasma electrolytic deposition

    Institute of Scientific and Technical Information of China (English)

    Jin Zhang

    2016-01-01

    Porousa-Al2O3 thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coatings and the CPED process were studied. The prepared coatings were mainly composed ofα-Al2O3. The average thickness of the coatings was approximately 100μm. Such single-layer TBCs ex-hibited not only excellent high-temperature cyclic oxidation and spallation resistance, but also good thermal insulation properties. Porousa-Al2O3 TBCs inhibit further oxidation of alloy substrates because of their extremely low oxygen diffusion rate, provide good thermal insu-lation because of their porous structure, and exhibit excellent mechanical properties because of the toughening effect of the Pt particles and because of stress relaxation induced by deformation of the porous structure.

  20. Synthesis of LSM films deposited by dip-coating on YSZ substrate; Sintese de filmes de LSM depositados por dip-coating em substratos de YSZ

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Leandro da; Souza, Mariana M.V.M., E-mail: mmattos@eq.ufrj.b [Universidade Federal do Rio de Janeiro (EQ/UFRJ), RJ (Brazil). Escola de Quimica; Ribeiro, Nielson F.P. [Coordenacao dos Programas de Pos-graduacao de Engenharia (PEQ/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Quimica. Nucleo de Catalise

    2010-07-01

    The dip-coating process was used to deposit films of La{sub 0.7}Sr{sub 0.}3MnO{sub 3} (LSM) used as cathode in solid oxide fuel cells (SOFC). In this study we evaluated the relationship between the deposition parameters such as speed of withdrawal and number of deposited layers of LSM film on a substrate of 8% YSZ commercial, and structural properties, such as thickness and formation of cracks. The structure and morphology of the films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). With parameters set the film had good adhesion to the substrate with a thickness around 10 {mu}m, showing possible adherence problems when more than one layer is deposited on the substrate. (author)

  1. Molecular plasma deposition: biologically inspired nanohydroxyapatite coatings on anodized nanotubular titanium for improving osteoblast density

    Directory of Open Access Journals (Sweden)

    Balasundaram G

    2015-01-01

    Full Text Available Ganesan Balasundaram,1 Daniel M Storey,1 Thomas J Webster2,3 1Chameleon Scientific, Longmont, CO, USA; 2Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 3Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: In order to begin to prepare a novel orthopedic implant that mimics the natural bone environment, the objective of this in vitro study was to synthesize nanocrystalline hydroxyapatite (NHA and coat it on titanium (Ti using molecular plasma deposition (MPD. NHA was synthesized through a wet chemical process followed by a hydrothermal treatment. NHA and micron sized hydroxyapatite (MHA were prepared by processing NHA coatings at 500°C and 900°C, respectively. The coatings were characterized before and after sintering using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The results revealed that the post-MPD heat treatment of up to 500°C effectively restored the structural and topographical integrity of NHA. In order to determine the in vitro biological responses of the MPD-coated surfaces, the attachment and spreading of osteoblasts (bone-forming cells on the uncoated, NHA-coated, and MHA-coated anodized Ti were investigated. Most importantly, the NHA-coated substrates supported a larger number of adherent cells than the MHA-coated and uncoated substrates. The morphology of these cells was assessed by scanning electron microscopy and the observed shapes were different for each substrate type. The present results are the first reports using MPD in the framework of hydroxyapatite coatings on Ti to enhance osteoblast responses and encourage further studies on MPD-based hydroxyapatite coatings on Ti for improved orthopedic applications. Keywords: hydroxyapatite, anodization, nanotechnology

  2. Microstructure and corrosion behavior of electroless deposited Ni-P/CeO2 coating

    Institute of Scientific and Technical Information of China (English)

    Hui Ming Jin; Shi Hang Jiang; Lin Nan Zhang

    2008-01-01

    Electroless Ni-P/nano-CeO2 composite coating was prepared in acidic condition,and its microstructure and corrosive property were compared with its CeO2-free counterpart.Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) spectrometer were used to examine surface morphology and structure of the as-plated coating.Differential scanning calorimeter (DSC) and transmission electronic microscopy (TEM) were used to study the coating's phase change at high temperature.The coating's corrosive behavior in 3%NaCI + 5%H2SO4 solution was also investigated.The results showed that Ni-P coating had partial amorphous structure mixed with nano-crystals,while the Ni-P/CeO2 coating had perfect amorphous structure.In high-temperature condition,Ni3P precipitation and Ni crystallization took place in both coatings but at different temperatures,while the Ni-P/CeO2 coating had sintered phase of NiCe2O4 spinels.The anti-corrosion property was better in the CeO2-containing coating,and this was due to its less liability to undergo local-cell corrosion than its CeO2-free counterpart.Ni-P/CeO2 coating's pure amorphous structure was the result of Ni's hindered crystal-typed deposition and P's promoted deposition.

  3. Substrate Frequency Effects on Cr x N Coatings Deposited by DC Magnetron Sputtering

    Science.gov (United States)

    Obrosov, Aleksei; Naveed, Muhammad; Volinsky, Alex A.; Weiß, Sabine

    2016-11-01

    Controlled ion bombardment is a popular method to fabricate desirable coating structures and modify their properties. Substrate biasing at high frequencies is a possible technique, which allows higher ion density at the substrate compared with DC current bias. Moreover, high ion energy along with controlled adatom mobility would lead to improved coating growth. This paper focuses on a similar type of study, where effects of coating growth and properties of DC magnetron-sputtered chromium nitride (Cr x N) coatings at various substrate bias frequencies are discussed. Cr x N coatings were deposited by pulsed DC magnetron sputtering on Inconel 718 and (100) silicon substrates at 110, 160 and 280 kHz frequency at low duty cycle. Coating microstructure and morphology were studied by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), scratch adhesion testing and nanoindentation. Results indicate a transformation of columnar into glassy structure of Cr x N coatings with the substrate bias frequency increase. This transformation is attributed to preferential formation of the Cr2N phase at high frequencies compared with CrN at low frequencies. Increase in frequency leads to an increase in deposition rate, which is believed to be due to increase in plasma ion density and energy of the incident adatoms. An increase in coating hardness along with decrease in elastic modulus was observed at high frequencies. Scratch tests show a slight increase in coating adhesion, whereas no clear increase in coating roughness can be found with the substrate bias frequency.

  4. In vivo evaluation of titanium implants coated with bioactive glass by pulsed laser deposition.

    Science.gov (United States)

    Borrajo, Jacinto P; Serra, Julia; González, Pío; León, Betty; Muñoz, Fernando M; López, M

    2007-12-01

    During the past years, different techniques, like chemical treatment, plasma spraying, sputtering, enamelling or sol-gel; and materials, like metals, hydroxylapatite, calcium phosphates, among others, have been applied in different combinations to improve the performance of prostheses. Among the techniques, Pulsed Laser Deposition (PLD) is very promising to produce coatings of bioactive glass on any metal alloy used as implant. In this work the biocompatibility of PLD coatings deposited on titanium substrates was examined by implantation in vivo. Different coating compositions were checked to find the most bioactive that was then applied on titanium and implanted into paravertebral muscle of rabbit.

  5. Structure and properties of protective coatings produced by vacuum arc deposition

    Energy Technology Data Exchange (ETDEWEB)

    Leontiev, S.A. [Leningradsky Metallitchesky Zavod, St. Petersburg (Russian Federation); Kuznetsov, V.G. [Machine Research Problems Institute, Russian Academy of Sciences V.O., Bolshoy pr. 61, 199178 St. Petersburg (Russian Federation); Rybnikov, A.I. [Polzunov Central Boiler and Turbine Institute (NPO TsKTI), Polytechnicheskaya 24, 194021 St. Petersburg (Russian Federation); Burov, I.V. [Machine Research Problems Institute, Russian Academy of Sciences V.O., Bolshoy pr. 61, 199178 St. Petersburg (Russian Federation)

    1995-11-01

    CoCrAlY, NiCrWTi and CoCrAlY/ZrO{sub 2}+8wt.%Y{sub 2}O{sub 3} coatings were deposited by vacuum arc evaporation. Coatings were deposited onto specimens for metallographic analysis, corrosion resistance testing, thermal fatigue testing, high-frequency fatigue and onto gas turbine blades. It has been shown by testing that the developed procedures ensure gas turbine blade coatings of high quality comparable with those manufactured by electron beam procedures. (orig.)

  6. Growth and Characterization of Carbon Nanofibers on Fe/C-Fiber Textiles Coated by Deposition-Precipitation and Dip-Coating.

    Science.gov (United States)

    Lee, Sang-Won; Lee, Chang-Seop

    2015-09-01

    This research was conducted to synthesize carbon nanofibers on C-fiber textiles, by thermal chemical vapor deposition (CVD) using Fe catalyst. The substrate, which was a carbon textile consisting of non-woven carbon fibers and attached graphite particles, was oxidized by nitric acid, before the deposition process. Hydroxyl groups were created on the C-fiber textile, due to the oxidization step. Fe(III) hydroxide was subsequently deposited on the oxidized surface of the C-fiber textile. To deposit ferric particles, two different methods were tested: (i) deposition-precipitation, and (ii) dip-coating. For the experiments using both types of catalyst deposition, the weight ratio of Fe to C-fiber textile was also varied. Ferric particles were reduced to iron after deposition, by using H2/N2 gas, and carbon nanofibers (CNFs) were grown by flowing ethylene gas. Properties of carbon nanofibers created like this were analyzed through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), N2-sorption (BET), X-ray Diffraction (XRD), X-ray Photoelectron Spectoscopy (XPS), Thermal analysis (TG/DTA), and Raman spectroscopy. In the case of the deposition-precipitation method, the results show that the diameter of carbon nanofibers grew up to 40-60 nm and 30-55 nm, at which the weight ratios of Fe catalyst to C-fiber textiles were 1:30 and 1:70, respectively. When Fe particles were deposited by the dip-coating method, the diameter of carbon nanofibers grew up to 40-60 nm and 25-30 nm, for the ratios of Fe catalyst to C-fiber textiles of 1:10 and 1:30, respectively.

  7. Film Coating Process Research and Characterization of TiN Coated Racetrack-type Ceramic Pipe

    CERN Document Server

    Wang, Jie; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiangtao; Hong, Yuanzhi; Wang, Yong

    2015-01-01

    TiN film was coated on the internal face of racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. According to the AFM, SEM, XPS test results,these properties were analyzed, such as TiN film roughness and surface morphology. At the same time, the deposition rates were studied under two types' cathode, Ti wires and Ti plate. According to the SEM test results, Ti plate cathode can improve the TiN/Ti film deposition rate obviously.

  8. The Research and Development of the External Magnetic Field Acting on Electro-Deposition Process

    Directory of Open Access Journals (Sweden)

    Wu Menghua

    2016-01-01

    Full Text Available The research and development status of the electro-deposition technology under the action of external magnetic field are introduced. The basic characteristics and applied manners of external magnetic field in electro-deposition process are summarized. The acting principle of external magnetic field, the effects of magnetic hydrodynamics (MHD caused by the Lorentz force, and the acting of magnetic force on the metal ions and particles are described. The main actions of external magnetic field include MHD effect, magnetizing force, affecting the physical and chemical properties of the bath, affecting the disperse ability and coverage capacity of bath, affecting the mass transfer process of electro-deposition, affecting the chemical reaction process and current distribution of electrode surface. Some examples of electro-depositing single metal coatings, alloy coatings and composite coatings under action of magnetic field are explained. During the electro-depositing process, the external magnetic field has different degrees of impact on solution properties, mass transfer, charge transfer, content of composited nanoparticles, crystal growth and crystal orientation etc. The specific impact of magnetic field during the electro-depositing is also classified and summarized. The problems that existed in electro-deposition process while applying magnetic field and the next development trend were summarized.

  9. Multifaceted and route-controlled "click" reactions based on vapor-deposited coatings.

    Science.gov (United States)

    Sun, Ting-Pi; Tai, Ching-Heng; Wu, Jyun-Ting; Wu, Chih-Yu; Liang, Wei-Chieh; Chen, Hsien-Yeh

    2016-02-01

    "Click" reactions provide precise and reliable chemical transformations for the preparation of functional architectures for biomaterials and biointerfaces. The emergence of a multiple-click reaction strategy has paved the way for a multifunctional microenvironment with orthogonality and precise multitasking that mimics nature. We demonstrate a multifaceted and route-controlled click interface using vapor-deposited functionalized poly-para-xylylenes. Distinctly clickable moieties of ethynyl and maleimide were introduced into poly-para-xylylenes in one step via a chemical vapor deposition (CVD) copolymerization process. The advanced interface coating allows for a double-click route with concurrent copper(i)-catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC) and the thiol-maleimide click reaction. Additionally, double-click reactions can also be performed in a cascade manner by controlling the initiation route to enable the CuAAC and/or thiol-yne reaction using a mono-functional alkyne-functionalized poly-para-xylylene. The use of multifaceted coatings to create straightforward and orthogonal interface properties with respect to protein adsorption and cell attachment is demonstrated and characterized.

  10. The Effect and Mechanism of Nano-Cu Lubricating Additives on the Electroless Deposited Ni-W-P Coating

    Institute of Scientific and Technical Information of China (English)

    CHEN Min; JIANG Xiaomin; ZHAO Zuxin; HUANG Xiaobo

    2012-01-01

    The coating and deposition process with excellent anti wear and suitable for industrial application were developed,and the optimum bath composition and process were obtained by studying the influence of the bath composition,temperature and pH value on the deposition rate and the plating solution stability.Moreover,the tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and energy dispersive spectrometer.Research results show that Ni-W-P alloy coating and nano-Cu lubricating additive have excellent synergistic effect,e g,the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano-Cu additives) has increased hundreds times than 45 steel as the metal substrate with the basic oil,and zero wear is achieved,which breaks through the bottleneck of previous separate research of the above-mentioned two aspects.

  11. Effect of Al Enrichment by Pack Cementation of FeCr Coatings Deposited by HVOF

    Science.gov (United States)

    Bellucci, A.; Bellini, S.; Pileggi, R.; Stocchi, D.; Tuurna, S.

    2015-01-01

    A great contribution to CO2 emissions comes from coal fired power generation. Combination of carbon capture sequestering technologies with sustainable biomass conversion constitutes a decisive boost in limiting rise in global temperature. Co-firing alternative materials with pulverized coal and using oxy-fuel combustion conditions (oxy-fuel co-combustion) is a very attractive process for power industry. Materials with both high mechanical properties and high environmental resistance are required by such advanced combustion systems. One approach to improve high-temperature oxidation/corrosion resistance is to apply protective coatings. In the present work, low and high Cr content Fe-based alloys have been deposited in order to investigate the influence of Cr content on coating protective performance in oxy-fuel co-combustion conditions. Grade 91 steel has been assumed as reference substrate. Effect of Al enrichment on coating environmental resistance has also been analyzed. Activities have been performed within the framework of Macplus Project (Integrated Project co-founded by the European Commission under the 7th Framework Program in the Energy area).

  12. Formation of hydroxyapatite coating on titanium at 200°C through pulsed laser deposition followed by hydrothermal treatment

    Indian Academy of Sciences (India)

    Manoj Komath; P Rajesh; C V Muraleedharan; H K Varma; R Reshmi; M K Jayaraj

    2011-04-01

    Pulsed laser deposition (PLD) has emerged as an acceptable technique to coat hydroxyapatite on titanium-based permanent implants for the use in orthopedics and dentistry. It requires substrate temperature higher than 400°C to form coatings of good adhesion and crystallinity. As this range of temperatures is likely to affect the bulk mechanical properties of the implant, lowering the substrate temperature during the coating process is crucial for the long-term performance of the implant. In the present study, hydroxyapatite target was ablated using a pulsed Nd:YAG laser (355 nm) onto commercially pure titanium substrates kept at 200°C. The coating thus obtained has been subjected to hydrothermal treatment at 200°C in an alkaline medium. The coatings were analysed using microscratch test, optical profilometry, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and infrared spectroscopy (FTIR). XRD, EDS and FTIR showed that the as-deposited coating contained amorphous calcium phosphate and the hydrothermal treatment converted it into crystalline hydroxyapatite. The micro-morphology was granular, with an average size of 1 micron. In the microscratch test, a remarkable increase in adhesion with the substrate was seen as a result of the treatment. The plasma plume during the deposition has been analysed using optical emission spectroscopy, which revealed atomic and ionic species of calcium, phosphorous and oxygen. The outcomes demonstrate the possibility of obtaining adherent and crystalline hydroxyapatite on titanium substrate at 200°C through pulsed laser deposition and subsequent hydrothermal treatment.

  13. Fluorocarbon coatings deposited on micron-sized particles by atmospheric PECVD

    NARCIS (Netherlands)

    Abadjieva, E.; Heijden, A.E.D.M. van der; Creyghton, Y.L.M.; Ommen, J.R. van

    2012-01-01

    Fluorocarbon coatings have been deposited on micron-sized silica particles by means of atmospheric pressure plasma-enhanced chemical vapor deposition (PECVD). The silica particles have a diameter in the range between 40 and 70 ?m. They are fluidized at atmospheric pressure in a circulating fluidized

  14. Deposition, Heat Treatment And Characterization of Two Layer Bioactive Coatings on Cylindrical PEEK.

    Science.gov (United States)

    Durham, John W; Rabiei, Afsaneh

    2016-09-15

    Polyether ether ketone (PEEK) rods were coated via ion beam asssited deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength.

  15. Performance evaluation of reactive direct current unbalanced magnetron sputter deposited nanostructured TiN coated high-speed steel drill bits

    Indian Academy of Sciences (India)

    Harish C Barshilia; K S Rajam

    2007-12-01

    The stainless steels, in general, are considered to be difficult-to-machine materials. In order to machine these materials the surface of the tool is generally coated with physical vapour deposition (PVD) hard coatings such as titanium nitride (TiN), titanium aluminum nitride (TiAlN), etc. The adhesion is of vital importance for the performance of tools coated with PVD coatings. Proper surface treatments (in situ and ex situ) are required to achieve highly adherent PVD coatings on tools. We have deposited nanostructured TiN coatings on high-speed steel (HSS) drill bits and mild steel substrates using an indigenously built semi-industrial fourcathode reactive direct current (d.c.) unbalanced magnetron sputtering system. Various treatments have been given to the substrates for improved adhesion of the TiN coatings. The process parameters have been optimized to achieve highly adherent thick good quality TiN coatings. These coatings have been characterized using X-ray diffraction, nanoindentation and atomic force microscopy techniques. The performance of the coated HSS drill bits is evaluated by drilling a 13 mm thick 304 stainless steel plate under wet conditions. The results show significant improvement in the performance of the TiN coated HSS drill bits.

  16. Deposition of dual-layer coating on Ti6Al4V

    Science.gov (United States)

    Hussain Din, Sajad; Shah, M. A.; Sheikh, N. A.

    2017-03-01

    Dual-layer diamond coatings were deposited on titanium alloy (Ti6Al4V) using a hot filament chemical vapour deposition technique with the anticipation of studying the structural and morphology properties of the alloy. The coated diamond films were characterized using scanning electron microscope, x-ray diffraction (XRD), and Raman spectroscopy. The XRD studies reveal that the deposited films are highly crystalline in nature, whereas morphological studies show that the films have a cauliflower structure. XRD analysis was used to calculate the structural parameters of the Ti6Al4V and CVD-coated Ti6Al4V. Raman spectroscopy was used to determine the nature and magnitude of the residual stress of the coatings.

  17. Electrophoretic deposition and electrochemical behavior of novel graphene oxide-hyaluronic acid-hydroxyapatite nanocomposite coatings

    Science.gov (United States)

    Li, Ming; Liu, Qian; Jia, Zhaojun; Xu, Xuchen; Shi, Yuying; Cheng, Yan; Zheng, Yufeng; Xi, Tingfei; Wei, Shicheng

    2013-11-01

    Novel ternary graphene oxide-hyaluronic acid-hydroxyapatite (GO-HY-HA) nanocomposite coatings were prepared on Ti substrate using anodic electrophoretic deposition (EPD). Hyaluronic acid was employed as charging additive and dispersion agent during EPD. The kinetics and mechanism of the deposition, and the microstructure of the coated samples were investigated using scanning electron microscopy, X-ray diffraction, Raman spectrum, thermo-gravimetric analysis, and microscopic Fourier transform infrared analysis. The results showed that the addition of GO sheets into the HY-HA suspensions could increase the deposition rate and inhibit cracks creation and propagation in the coatings. The corrosion resistant of the resulting samples were evaluated using potentiodynamic polarization method in simulated body fluid, and the GO-HY-HA coatings could effectively improve the anti-corrosion property of the Ti substrate.

  18. Single-walled carbon nanotubes coated with ZnO by atomic layer deposition

    Science.gov (United States)

    Pal, Partha P.; Gilshteyn, Evgenia; Jiang, Hua; Timmermans, Marina; Kaskela, Antti; Tolochko, Oleg V.; Kurochkin, Alexey V.; Karppinen, Maarit; Nisula, Mikko; Kauppinen, Esko I.; Nasibulin, Albert G.

    2016-12-01

    The possibility of ZnO deposition on the surface of single-walled carbon nanotubes (SWCNTs) with the help of an atomic layer deposition (ALD) technique was successfully demonstrated. The utilization of pristine SWCNTs as a support resulted in a non-uniform deposition of ZnO in the form of nanoparticles. To achieve uniform ZnO coating, the SWCNTs first needed to be functionalized by treating the samples in a controlled ozone atmosphere. The uniformly ZnO coated SWCNTs were used to fabricate UV sensing devices. An UV irradiation of the ZnO coated samples turned them from hydrophobic to hydrophilic behaviour. Furthermore, thin films of the ZnO coated SWCNTs allowed us switch p-type field effect transistors made of pristine SWCNTs to have ambipolar characteristics.

  19. Long length coated conductor fabrication by inclined substrate deposition and evaporation

    Science.gov (United States)

    Prusseit, W.; Hoffmann, C.; Nemetschek, R.; Sigl, G.; Handke, J.; Lümkemann, A.; Kinder, H.

    2006-06-01

    The commercial development of coated conductors is rapidly progressing. As a result we present an economic route to produce second generation HTS tape from the initial substrate preparation to the final metal coating. The most important and technically challenging steps are the deposition of an oriented buffer layer and the superconductor film in a reel-to-reel configuration. New evaporation techniques have been developed to enable reliable, high rate tape coating. Highly oriented MgO - buffer layers are realized by inclined substrate deposition (ISD) and DyBCO is deposited by simple e-gun evaporation yielding critical currents beyond 200 A/cm. Coated conductors have been fabricated up to 40 m length and are currently tested in a variety of applications.

  20. Status of Plasma Physics Techniques for the Deposition of Tribological Coatings

    Science.gov (United States)

    Spalvins, T.

    1984-01-01

    The plasma physics deposition techniques of sputtering and ion-plating are reviewed. Their characteristics and potentials are discussed in terms of synthesis or deposition of tribological coatings. Since the glow discharge or plasma generated in the conventional sputtering and ion-plating techniques has a low ionization efficiency, rapid advances have been made in equipment design to further increase the ionization efficiency. The enhanced ionization favorably affects the nucleation and growth sequence of the coating. This leads to improved adherence and coherence, higher density, favorable morphological growth, and reduced internal stresses in the coatings. As a result, desirable coating characteristics can be precision tailored. Tribological coating characteristics of sputtered solid film lubricants such as MoS2, ion-plated soft gold and lead metallic films, and sputtered and ion-plated wear-resistant refractory compound films such as nitrides and carbides are discussed.

  1. Electrolytic deposition of Sn-coated mesocarbon microbeads as anode material for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Min-Jen [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Jen-Teh Junior College of Medicine, Nursing and Management, Taiwan (China); Tsai, Du-Cheng [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Ho, Wen-Hsien [Taiwan Textile Research Institute, Taipei 23674, Taiwan (China); Li, Ching-Fei, E-mail: chingfei.li@gmail.com [Phoenix Silicon International Corporation, Hsinchu 30094, Taiwan (China); Shieu, Fuh-Sheng, E-mail: fsshieu@dragon.nchu.edu.tw [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2013-11-15

    Deposited of crystalline tin (Sn) coatings on mesocarbon microbead (MCMB) powder as anodes of lithium ion (Li-ion) battery was conducted in the SnSO{sub 4} solution by a cathodic electrochemical synthesis. The Sn-coated MCMB specimens were characterized by X-ray diffraction, scanning electron microscopy, and charge/discharge tests. The synthesis condition of Sn-coated MCMB was optimized by considering the agglomeration, size, and adhesion of the samples to the current collectors in the battery. The Sn-coated MCMB electrodes exhibit increased reversible capacity without sacrificing its cycling behavior, compared with bare MCMB electrodes. It is concluded that electrolysis-deposited Sn-coated MCMB electrodes may emerge as a practical and promising anode material for secondary Li-ion batteries.

  2. Coating and functionalization of high density ion track structures by atomic layer deposition

    Science.gov (United States)

    Mättö, Laura; Szilágyi, Imre M.; Laitinen, Mikko; Ritala, Mikko; Leskelä, Markku; Sajavaara, Timo

    2016-10-01

    In this study flexible TiO2 coated porous Kapton membranes are presented having electron multiplication properties. 800 nm crossing pores were fabricated into 50 μm thick Kapton membranes using ion track technology and chemical etching. Consecutively, 50 nm TiO2 films were deposited into the pores of the Kapton membranes by atomic layer deposition using Ti(iOPr)4 and water as precursors at 250 °C. The TiO2 films and coated membranes were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray reflectometry (XRR). Au metal electrode fabrication onto both sides of the coated foils was achieved by electron beam evaporation. The electron multipliers were obtained by joining two coated membranes separated by a conductive spacer. The results show that electron multiplication can be achieved using ALD-coated flexible ion track polymer foils.

  3. Dual Bath Electrodeposition of Alternate Multilayer Coatings of Zinc and Nickel Deposits

    Institute of Scientific and Technical Information of China (English)

    XIN Wen-li; FEI Jing-yin; LIANG Guo-zheng

    2004-01-01

    The synthesis of zinc and nickel alternate multilayer coatings produced by successive deposition from dual baths containing a revised zinc sulphate electrolyte and a new developed nickel bath has been investigated. Smooth and uniform zinc-nickel compositionally modulated multilayered (CMM) coatings with different multilayer configurations were obtained. The surface and cross-sectional morphologies of samples were examined using scanning electron microscopy (SEM). Cross-sectional morphology showed the layered structure of the coatings clearly.Key Words: multilayer coating, electrodeposited zinc and nickel, electrodeposition

  4. MCrA1Y/TaC Metal Matrix Composite Coatings Produced by Electrospark Deposition

    Institute of Scientific and Technical Information of China (English)

    Yujiang XIE; Yanhong YANG; Mingsheng WANG; Jian HOU

    2013-01-01

    MCrAlY/TaC metal matrix composite coatings with 10,20 and 30 wt.% TaC have been successfully produced by electrospark deposition (ESD).The effects of TaC content on microstructure,hardness and oxidation behavior of the composite coatings were studied.The results showed that the composite coatings were composed of superfine γ columnar dendrite and large TaC particles dispersedly distributed.The hardness was enhanced but oxidation resistance of the composite coatings was reduced with increasing TaC contents.

  5. Preparation and analysis of chemically gradient functional bioceramic coating formed by pulsed laser deposition.

    Science.gov (United States)

    Rajesh, P; Muraleedharan, C V; Sureshbabu, S; Komath, Manoj; Varma, Harikrishna

    2012-02-01

    Bioactive ceramic coatings based on calcium phosphates yield better functionality in the human body for a variety of metallic implant devices including orthopaedic and dental prostheses. In the present study chemically and hence functionally gradient bioceramic coating was obtained by pulsed laser deposition method. Calcium phosphate bioactive ceramic coatings based on hydroxyapatite (HA) and tricalcium phosphate (TCP) were deposited over titanium substrate to produce gradation in physico-chemical characteristics and in vitro dissolution behaviour. Sintered targets of HA and α-TCP were deposited in a multi target laser deposition system. The obtained deposits were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray analysis. Inductively coupled plasma spectroscopy was used to estimate the in vitro dissolution behaviour of coatings. The variation in mechanical property of the gradient layer was evaluated through scratch test and micro-indentation hardness. The bioactivity was examined in vitro with respect to the ability of HA layer to form on the surface as a result of contact with simulated body fluid. It could be inferred that chemically gradient functional bioceramic coating can be produced by laser deposition of multiple sintered targets with variable chemical composition.

  6. Apparatus and process for atomic or molecular layer deposition onto particles during pneumatic transport

    NARCIS (Netherlands)

    Van Ommen, J.R.

    2010-01-01

    The invention provides a process for depositing a coating onto particles being pneumatically transported in a tube. The process comprising the steps of providing a tube having an inlet opening and an outlet opening; feeding a carrier gas entraining particles into the tube at or near the inlet openin

  7. Effect of corona pre-treatment on the performance of gas barrier layers applied by atomic layer deposition onto polymer-coated paperboard

    Energy Technology Data Exchange (ETDEWEB)

    Hirvikorpi, Terhi, E-mail: terhi.hirvikorpi@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, P.O. Box 1000, FI-02044 VTT Espoo (Finland); Vaehae-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, P.O. Box 1000, FI-02044 VTT Espoo (Finland); Harlin, Ali, E-mail: ali.harlin@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, P.O. Box 1000, FI-02044 VTT Espoo (Finland); Marles, Jaana, E-mail: jaana.marles@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Miikkulainen, Ville, E-mail: ville.miikkulainen@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Karppinen, Maarit, E-mail: maarit.karppinen@tkk.fi [Aalto University School of Technology and Science, Laboratory of Inorganic Chemistry, Kemistintie 1A, Espoo, P.O. Box 16100, 00076 Aalto (Finland)

    2010-11-15

    The effect of corona pre-treatment on the performance of Al{sub 2}O{sub 3} and SiO{sub 2} gas barrier layers applied by atomic layer deposition onto polymer-coated paperboards was studied. Both polyethylene and polylactide coated paperboards were corona treated prior to ALD. Corona treatment increased surface energies of the paperboard substrates, and this effect was still observed after several days. Al{sub 2}O{sub 3} and SiO{sub 2} films were grown on top of the polymer coatings at temperature of 100 deg. C using the atomic layer deposition (ALD) technique. For SiO{sub 2} depositions a new precursor, bis(diethylamido) silane, was used. The positive effect of the corona pre-treatment on the barrier properties of the polymer-coated paperboards with the ALD-grown layers was more significant with polyethylene coated paperboard and with thin deposited layers (shorter ALD process). SiO{sub 2} performed similarly to Al{sub 2}O{sub 3} with the PE coated board when it comes to the oxygen barrier, while the performance of SiO{sub 2} with the biopolymer-coated board was more moderate. The effect of corona pre-treatment was negligible or even negative with the biopolymer-coated board. The ALD film growth and the effect of corona treatment on different substrates require further investigation.

  8. Plasma immersion ion implantation and deposition of DLC coating for modification of orthodontic magnets

    Energy Technology Data Exchange (ETDEWEB)

    Wongsarat, W. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sarapirom, S. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); National Metal and Materials Technology Center, 114 Thailand Science Park, Paholyothin Road, Klong 1, Klong Luang, Pathumthani, Bangkok 12120 (Thailand); Aukkaravittayapun, S. [National Metal and Materials Technology Center, 114 Thailand Science Park, Paholyothin Road, Klong 1, Klong Luang, Pathumthani, Bangkok 12120 (Thailand); Jotikasthira, D. [Department of Odontology-Oral Pathology, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200 (Thailand); Boonyawan, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2012-02-01

    This study was aimed to use the plasma immersion ion implantation and deposition (PIII-D) technique to form diamond-like carbon (DLC) thin films on orthodontic magnets to solve the corrosion problem. To search for the optimal material modification effect, PIII-D conditions including gases, processing time, and pulsing mode were varied. The formation of DLC films was confirmed and characterized with Raman spectra. The intensity of the remnant magnetic field of the magnets and the hardness, adhesion and thickness of the thin films were then measured. A corrosion test was carried out using clinic dental fluid. Improved benefits including a satisfying hardness, adhesion, remnant magnetic strength and corrosion resistance of the DLC coating could be achieved by using a higher interrupting time ratio and shorter processing time.

  9. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Blanda, Giuseppe [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Piazza, Salvatore; Sunseri, Carmelo [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Inguanta, Rosalinda, E-mail: rosalinda.inguanta@unipa.it [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO{sub 4}·H{sub 2}O; HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO{sub 3}){sub 2}·4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

  10. Electrophoretic co-deposition of polyvinyl alcohol (PVA) reinforced alginate–Bioglass® composite coating on stainless steel: Mechanical properties and in-vitro bioactivity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiang; Cabanas-Polo, Sandra; Goudouri, Ourania-Menti; Boccaccini, Aldo R., E-mail: aldo.boccaccini@ww.uni-erlangen.de

    2014-07-01

    PVA reinforced alginate–bioactive glass (BG) composite coatings were produced on stainless steel by a single step electrophoretic deposition (EPD) process. The present paper discusses the co-deposition mechanism of the three components and presents a summary of the relevant properties of the composite coatings deposited from suspensions with different PVA concentrations. Homogeneous composite coatings with compact microstructure and increased thickness, i.e. as high as 10 μm, were observed by scanning electron microscopy (SEM). The surface roughness of coatings with different PVA contents was slightly increased, while a significant increase of water contact angles due to PVA addition was detected and discussed. Improved adhesion strength of coatings containing different amounts of PVA was quantitatively and qualitatively confirmed by pull-off adhesion and cycled bending tests, respectively. In-vitro bioactivity tests were performed in simulated body fluid (SBF) for 0.5, 1, 2, 4, 7, and 14 days, respectively. The decomposition rate of the coatings was reduced with PVA content, and rapid hydroxyapatite forming ability of the composite coatings in SBF was confirmed by FTIR and XRD analyses. According to the results of this study, composite alginate–Bioglass® bioactive coatings combined with PVA are proposed as promising candidates for dental and orthopedic applications. - Highlights: • PVA reinforced alginate–bioactive glass composite coating on stainless steel produced by EPD • The co-deposition mechanism was experimentally confirmed. • Homogeneous and compact coating microstructure obtained by the addition of PVA • Improved adhesion strength of PVA reinforced coatings confirmed qualitatively and quantitatively • Controlled degradation rate and rapid HA forming ability of PVA-containing coatings in SBF.

  11. Influence of precursor solution parameters on chemical properties of calcium phosphate coatings prepared using Electrostatic Spray Deposition (ESD).

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

    2004-01-01

    A novel coating technique, referred to as Electrostatic Spray Deposition (ESD), was used to deposit calcium phosphate (CaP) coatings with a variety of chemical properties. The relationship between the composition of the precursor solutions and the crystal and molecular structure of the deposited coa

  12. Microstructure, Processing, Performance Relationships for High Temperature Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Thomas M. Lillo

    2011-04-01

    This work evaluates the suitability of iron aluminide coatings for use in high temperature fossil fuel combustion environments, such as boiler applications. The coatings are applied using High Velocity Oxy-Fuel (HVOF) thermal spray techniques. Iron aluminide coatings, with the nominal composition of Fe3Al, were applied to various high temperature structural materials (316 Stainless Steel, 9Cr-1Mo steel and Inconel 600) that typically lack inherent resistance to environmental degradation found in fossil fuel combustion atmospheres. Coating/substrate combinations were subjected to thermal cycling to evaluate the effect of HVOF parameters, coating thickness, substrate material and substrate surface roughness on the resistance to coating delamination and cracking. It was found that substrate surface roughness had a profound influence on the performance of a given substrate/coating system and that surface preparation techniques will need to be tailored to the specific substrate material. Also, higher particle velocity during HVOF thermal spray deposition of the iron aluminide coatings tended to result in better-performing coating/substrate systems with less delamination at the coating/substrate interface. Some combinations of HVOF parameters, coating thickness and substrate materials were found to perform extremely well even at temperatures up to 900oC. However, in some cases, substantial reactions at the interface were observed.

  13. Tribological and structural properties of titanium nitride and titanium aluminum nitride coatings deposited with modulated pulsed power magnetron sputtering

    Science.gov (United States)

    Ward, Logan

    The demand for economical high-performance materials has brought attention to the development of advanced coatings. Recent advances in high power magnetron sputtering (HPPMS) have shown to improve tribological properties of coatings. These coatings offer increased wear and oxidation resistance, which may facilitate the use of more economical materials in harsh applications. This study demonstrates the use of novel forms of HPPMS, namely modulated pulsed-power magnetron sputtering (MPPMS) and deep oscillation magnetron sputtering (DOMS), for depositing TiN and Ti1-xAlxN tribological coatings on commonly used alloys, such as Ti-6Al-4V and Inconel 718. Both technologies have been shown to offer unique plasma characteristics in the physical vapor deposition (PVD) process. High power pulses lead to a high degree of ionization compared to traditional direct-current magnetron sputtering (DCMS) and pulsed magnetron sputtering (PMS). Such a high degree of ionization was previously only achievable by cathodic arc deposition (CAD); however, CAD can lead to increased macroparticles that are unfavorable in high friction and corrosive environments. MPPMS, DOMS, and other HPPMS techniques offer unique plasma characteristics and have been shown to produce coatings with refined grain structure, improved density, hardness, adhesion, and wear resistance. Using DOMS and MPPMS, TiN and Ti1-xAlxN coatings were deposited using PMS to compare microstructures and tribological performance. For Ti1-xAlxN, two sputtering target compositions, Ti 0.5Al0.5 and Ti0.3Al0.7, were used to evaluate the effects of MPPMS on the coating's composition and tribological properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize microstructure and crystallographic texture. Several tribological properties were evaluated including: wear rate, coefficient of friction, adhesion, and nanohardness. Results show that substrate

  14. Electrochemical behavior of TiAlSiN hard coatings synthesized by a multi-plasma immersion ion implantation and deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gengzhu [University of Science and Technology Liaoning, Anshan 114051 (China); Xie, Zhiwen, E-mail: xzw@cigit.ac.cn [University of Science and Technology Liaoning, Anshan 114051 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Chen, Tian [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Chen, Zhenyu [Key Laboratory of Power Sources, Institute of Power Sources, Tianjin 300381 (China); Song, Xiaohang [Shanghai Aerospace Equipments Manufacturer, Shanghai 401122 (China); Gao, Xu; Yu, Xiaoguang; Song, Hua [University of Science and Technology Liaoning, Anshan 114051 (China)

    2015-06-01

    The TiAlSiN coatings are synthesized by a multi-plasma immersion ion implantation and deposition technique. The microstructure and the electrochemical behavior of the as-deposited coatings are investigated by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and electrochemical tests. These studies reveal that huge lattice distortions and dislocations emerge in the coating after introducing a small amount of Al component. These structural defects can facilitate the corrosion process of the TiAlN coating. The TiAlN coating exhibits a worse corrosion resistance performance than the TiN coating. The TiAlSiN coating has a two phase microstructure, nc-TiAlN/a-Si{sub 3}N{sub 4.} The grain size is greatly reduced after introducing Si component, whereas the portion of the a-Si{sub 3}N{sub 4} phase increases as the amount of Si increases in the coating. The reduced grain size and the increased percentage of the a-Si{sub 3}N{sub 4} phase in the TiAlSiN coatings enhance their ability in corrosion resistance. The TiAlSiN coating with a larger amount of Si shows better corrosion resistance performance. This research provides a comprehensive understanding of the relationship between the microstructure and the electrochemical behavior of the TiAlSiN hard coatings. - Highlights: • Microstructure and electrochemical behavior of TiAlSiN coatings are presented. • Al addition induces serious lattice distortions and dislocations. • Si incorporation induces an obvious grain refinement effect. • TiAlN coating shows a higher corrosion rate than the TiN coating. • TiAlSiN coating with higher Si content shows better corrosion resistance.

  15. The structure of the tungsten coatings deposited by Combined Magnetron Sputtering and Ion Implantation for nuclear fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Grigore, E., E-mail: edigrig@infim.ro [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association (Romania); Ruset, C. [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association (Romania); Rasinski, M. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Gherendi, M. [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association (Romania); Matthews, G.F. [Culham Centre for Fusion Energy, Euratom Association, Abingdon (United Kingdom)

    2015-10-15

    Combined Magnetron Sputtering and Ion Implantation (CMSII) technology was used for W coating of about 1800 CFC tiles for ITER-like Wall (ILW) at JET and more than 1300 fine grain graphite tiles for ASDEX Upgrade tokamak. Thermal fatigue and carbidization due to the diffusion of the carbon from the substrate were found as main phenomena limiting the service lifetime of the W coatings. Detailed investigation of these coatings using SEM and STEM (scanning transmission electron microscopy) together with the FIB (focused ion beam) cutting technique revealed two fine networks of nano-pores with the size of 10–20 nm for zones of 250–350 nm at CFC-Mo and Mo-W interfaces. Formation of these nano-pores is associated with the energy of the ions striking the coating during the deposition process. By optimizing this energy the nano-pores disappeared. The structure and the performances of the W coatings produced by the new modified technology (CMSII-M) were compared with those deposited by standard benchmark technology. The HHF (high heat flux) tests carried out with an electron beam at a temperature of 1450 °C indicated a decrease of the defects affected area by a factor of about 1.7.

  16. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  17. Coating and functionalization of high density ion track structures by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mättö, Laura [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland); Szilágyi, Imre M., E-mail: imre.szilagyi@mail.bme.hu [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4, Budapest H-1111 (Hungary); MTA-BME Technical Analytical Research Group, Szent Gellért tér 4, Budapest H-1111 (Hungary); Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014 (Finland); Laitinen, Mikko [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland); Ritala, Mikko; Leskelä, Markku [Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014 (Finland); Sajavaara, Timo [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 (Finland)

    2016-10-01

    In this study flexible TiO{sub 2} coated porous Kapton membranes are presented having electron multiplication properties. 800 nm crossing pores were fabricated into 50 μm thick Kapton membranes using ion track technology and chemical etching. Consecutively, 50 nm TiO{sub 2} films were deposited into the pores of the Kapton membranes by atomic layer deposition using Ti({sup i}OPr){sub 4} and water as precursors at 250 °C. The TiO{sub 2} films and coated membranes were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray reflectometry (XRR). Au metal electrode fabrication onto both sides of the coated foils was achieved by electron beam evaporation. The electron multipliers were obtained by joining two coated membranes separated by a conductive spacer. The results show that electron multiplication can be achieved using ALD-coated flexible ion track polymer foils. - Highlights: • Porous Kapton membranes were obtained by ion track technology and chemical etching. • TiO{sub 2} films were deposited by ALD into the pores of the Kapton membranes. • TiO{sub 2} nanotube array was prepared by removing the polymer core. • MCP structures were obtained from the coated membranes. • Electron multiplication was achieved using the ALD-coated Kapton foils.

  18. MONTE-CARLO SIMULATION FOR ATOMIC DEPOSITION OF AMORPHOUS ELECTROLESS Ni80P20 COATING

    Institute of Scientific and Technical Information of China (English)

    K.S. Guan; H.R. Bai; Z.W. Wang; Y.S. Yin

    2002-01-01

    Atomic growth process and structure of Amorphous Electroless Coating have beenstudied, using Monte-Carlo simulation method. The simulation results of amorphousNi80P20 coating show that PDFs are in accordance with practical values. The mi-grations of adatoms in coating's growth are different from that of solidification ofamorphous materials. In some cases, the migrated adatoms in the process of growthof amorphous coating are not enough to occupy all vacancies and traps, so the amor-phous coating is micro-porous. The immovable probability k and the largest migrationdistance of adatoms, which lie on the electroless bath components, affect the PDF,volume density and microporosity remarkably.

  19. Stress Analysis in Polymeric Coating Layer Deposited on Rigid Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Soon Lee [Korea University of Technology and Education, School of Mechatronics Engineering, Chonan (Korea, Republic of)

    2015-08-15

    This paper presents an analysis of thermal stress induced along the interface between a polymeric coating layer and a steel substrate as a result of uniform temperature change. The epoxy layer is assumed to be a linear viscoelastic material and to be theromorheologically simple. The viscoelastic boundary element method is employed to investigate the behavior of interface stresses. The numerical results exhibit relaxation of interface stresses and large stress gradients, which are observed in the vicinity of the free surface. Since the exceedingly large stresses cannot be borne by the polymeric coating layer, local cracking or delamination can occur at the interface corner.

  20. Preparation and mechanical properties of two nickel base alloy coatings achieved by electrospark deposition

    Institute of Scientific and Technical Information of China (English)

    Ping ZHANG; Lin MA; Zhijie LIANG; Junjun ZHAO

    2011-01-01

    Ni398 and Ni818 base alloy coatings were deposited on 1045 steel by electrospark deposition technique (ESD).Forming properties,thickness,microhardness and wear resistance of the coatings were investigated.The chemical composition and crosssection morphology were analyzed through energy dispersive spectrum (EDS) and metalloscope.The results show that the technological parameter window of Ni398 is larger than that of Ni818 electrode.However,other properties of the Ni818 coating,such as thickness and microhardness,were better than those of the Ni398 coating.Especially the wornout volume of Ni818 coating is only 1/6 of that for 1045 steel and 1/3 for Ni398 coating.Chemical composition analysis indicated that the addition of Mo promoted grain refinement of nickel alloy.Metallographic analysis shows that the molten droplets of Ni398 coatings have an average structure thickness of 20-40 μm while the microstructure of Ni818 coatings is flat with width of 5-20 μm.

  1. ZrO(2)/hydroxyapatite coating on titanium by electrolytic deposition.

    Science.gov (United States)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Yang, Chih-Hsiung; Ho, Wen-Fu

    2009-02-01

    In this study, hydroxyapatite (HA) was coated on a titanium (Ti) substrate over a ZrO(2) layer by the electrolytic deposition method, this double layer coating was then compared with a single layer coating of HA. The HA layer was used to increase the bioactivity and osteoconductivity of the Ti substrate, and the ZrO(2) layer was intended to improve the bonding strength between the HA layer and Ti substrate, and to prevent the corrosion of the Ti substrate. The electrolytic deposition formed an HA layer with a thicknesses of approximately 20 mum, which adhered tightly to the Ti substrate. The bonding strength of the HA/ZrO(2) double layer coating on Ti was markedly improved when compared to that of the HA single coating on Ti. The improvement in bonding strength with the use of a ZrO(2) base layer was attributed to the resulting increase in chemical affinity of the ZrO(2) to the HA layer and to the Ti substrate. The osteoblast-like cells cultured on the HA/ZrO(2) coating surface, proliferated in a similar manner to those on the HA single coating and on the pure Ti surfaces. At the same time, the corrosion resistance of Ti was improved by the presence of the ZrO(2) coating, as shown by a potentiodynamic polarization test.

  2. Particle emission rates during electrostatic spray deposition of TiO2 nanoparticle-based photoactive coating

    DEFF Research Database (Denmark)

    Koivisto, Antti J.; Jensen, Alexander C. Ø.; Kling, Kirsten I.

    2017-01-01

    to 31μm-size particles and volatile organic compounds (VOC), as well as particle deposition onto room surfaces and on the spray gun user hand. The particle emission and deposition rates were quantified using aerosol mass balance modelling. The geometric mean particle number emission rate was 1.9×1010s-1...... and the mean mass emission rate was 381μgs-1. The respirable mass emission-rate was 65% lower than observed for the entire measured size-range. The mass emission rates were linearly scalable (±ca. 20%) to the process duration. The particle deposition rates were up to 15h-1 for......Here, we studied the particle release rate during Electrostatic spray deposition of anatase-(TiO2)-based photoactive coating onto tiles and wallpaper using a commercially available electrostatic spray device. Spraying was performed in a 20.3m3 test chamber while measuring concentrations of 5.6nm...

  3. The atmospheric chemical vapour deposition of coatings on glass

    CERN Document Server

    Sanderson, K D

    1996-01-01

    The deposition of thin films of indium oxide, tin doped indium oxide (ITO) and titanium nitride for solar control applications have been investigated by Atmospheric Chemical Vapour Deposition (APCVD). Experimental details of the deposition system and the techniques used to characterise the films are presented. Results from investigations into the deposition parameters, the film microstructure and film material properties are discussed. A range of precursors were investigated for the deposition of indium oxide. The effect of pro-mixing the vaporised precursor with an oxidant source and the deposition temperature has been studied. Polycrystalline In sub 2 O sub 3 films with a resistivity of 1.1 - 3x10 sup - sup 3 OMEGA cm were obtained with ln(thd) sub 3 , oxygen and nitrogen. The growth of ITO films from ln(thd) sub 3 , oxygen and a range of tin dopants is also presented. The effect of the dopant precursor, the doping concentration, deposition temperature and the effect of additives on film growth and microstr...

  4. Chemical vapor deposition fabrication and characterization of silica-coated carbon fiber ultramicroelectrodes.

    Science.gov (United States)

    Zhao, G; Giolando, D M; Kirchhoff, J R

    1995-08-01

    Carbon fiber disk ultramicroelectrodes (UMEs) with well-defined geometries were prepared by chemical vapor deposition techniques. Transparent silica films with thicknesses from 1 to 600 microns were deposited on the cylindrical length of 5 and 10 microns carbon fibers from a SiCl4, H2, and O2 ternary precursor system at 850-1150 degrees C or sequential deposition from Si(OEt)4 as a single source precursor at 700 degrees C followed by the SiCl4, H2, and O2 precursor system. Film thickness, film adhesion to the fiber substrate, and the overall dimensions of the silica-coated carbon fiber were studied and found to be a function of the precursor system, precursor concentrations, fiber diameter, deposition time, and fiber temperature. The silica films were found to be free of microcracks and characterized by a quality seal between the carbon fiber and the coating. As a result, the silica-coated disk UME exhibits an excellent electrochemical response without the need to use an epoxy sealant at the electrode tip. Furthermore, the deposition of hard and inert ceramic materials imparts durability to fragile carbon fibers and facilitates the handling of UMEs in microenvironments. Finally, the advantage of concentric deposition about the fibers to produce a disk UME in the center of an insulating plane was used to examine the effect of the thickness of the insulating coating on the limiting current response.

  5. The peculiarities of electrochemical deposition and morphology of ZnMn alloy coatings obtained from pyrophosphate electrolyte

    Directory of Open Access Journals (Sweden)

    Bučko Mihael M.

    2011-01-01

    Full Text Available The first successful attempt to electrodeposit ZnMn alloy coatings from alkaline bath was made only a few years ago. In this kind of solution, potassium pyrophosphate (K4P2O7 serves both as a complexing agent and as the basic electrolyte. The aim of this work was to study the electrodeposition process and properties of ZnMn alloy coatings deposited from pyrophosphate solution, with a new kind of alkaline pyrophosphate bath. Namely, chloride salts were used as the source of metal ions and ascorbic acid was used as reducing agent. The composition of the plating solution was as follows: 1 mol dm-3 K4P2O7 + 0.017 mol dm-3 ascorbic acid + 0.05 mol dm-3 ZnCl2 + 0.05 mol dm-3 MnCl2•4H2O. Cathodic processes during the alloy electrodeposition were investigated using linear voltammetry. The influence of addition of small amounts of ascorbic acid on the cathodic processes was established. It was shown that this substance inhibits hydrogen evolution and increases the current efficiency of alloy deposition. The current efficiency in the plating bath examined was in the range of 25 and 30%, which was quite higher as compared to the results reported in the literature for electrodeposition of ZnMn alloy from pyrophosphate bath. Electrodeposition of ZnMn alloys was performed galvanostatically on steel panels, at current densities of 20120 mA cm-2. The coatings with the best appearance were obtained at current densities between 30 and 80 mA cm-2. The surface morphology studies, based on atomic force microscopy measurements, showed that morphology of the deposits is highly influenced by deposition current density. ZnMn coating deposited at 30 mA cm-2 was more compact and possessed more homogeneous structure (more uniform agglomeration size than the coating deposited at 80 mA cm-2. Such dependence of morphology on the current density could be explained by the high rate of hydrogen evolution reaction during the electrodeposition process.

  6. lectrolytic deposition of lithium into calcium phosphate coatings

    NARCIS (Netherlands)

    Wang, Jiawei; Groot, de Klaas; Blitterswijk, van Clemens; Boer, de Jan

    2009-01-01

    Objectives: Lithium ions stimulate the Wnt signaling pathway and the authors previously demonstrated that lithium enhances the proliferation of tissue cultured human mesenchymal stem cells. The aim of this study was to prepare and characterize a calcium phosphate/lithium coating by means of electrol

  7. Plasma thermal performance of a dual-process PVD/PS tungsten coating on carbon-based panels for nuclear fusion application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunmyung; Lee, Ho Jung; Kim, Sung Hwan; Jang, Changheui, E-mail: chjang@kaist.ac.kr

    2016-11-01

    Highlights: • Plasma thermal performance of a dual-process PVD/PS W coating was evaluated. • Steady-state heat fluxes of 1–3 MW/m{sup 2} were applied to the W coated specimens. • Less micro-pores and grain growth were observed for the dual-process coating. • Loss of coating thickness was observed for the simple PS W coating. • Dual-process PVD/PS W coating was resistant to erosion due to the surface PVD layer. - Abstract: Various tungsten (W) coating techniques have been used for the application of plasma facing material in nuclear fusion devices, which resulted in limited success. In this study, a dual-process W coating structure was developed on a graphite substrate to improve the thermal performance of the coating structure. The dual-process coating structure consisted of a thin (∼7 μm) multilayer W/Mo physical vapor deposition (PVD) coating layer deposited on top of the relatively thick (∼160 μm) plasma spray (PS) W coating on a graphite substrate panel. Then the coated sample was exposed to plasma heat flux of 1–3 MW/m{sup 2} for 300 s. With addition of a thin surface PVD coating layer, the microstructure change in underlying PS W coating was substantially reduced compared to the simple PS W coating structure. The thickness of overall coating structure was maintained for the dual-process PVD/PS coated samples after the thermal loading tests, while a significant reduction in thickness due to surface erosion was observed for the simple PS W coated samples. The improvement in surface erosion resistance in the dual-process coating structure was discussed in view of the characteristics of PVD and PS coating layers.

  8. Fabrication of nano-structured HA/CNT coatings on Ti6Al4V by electrophoretic deposition for biomedical applications.

    Science.gov (United States)

    Zhang, Bokai; Kwok, Chi Tat; Cheng, Fai Tsun; Man, Hau Chung

    2011-12-01

    In order to improve the bone bioactivity and osteointegration of metallic implants, hydroxyapatite (HA) is often coated on their surface so that a real bond with the surrounding bone tissue can be formed. In the present study, cathodic electrophoretic deposition (EPD) has been attempted for depositing nanostructured HA coatings on titanium alloy Ti6Al4V followed by sintering at 800 degrees C. Nano-sized HA powder was used in the EPD process to produce dense coatings. Moreover, multiwalled carbon nanotubes (CNTs) were also used to reinforce the HA coating for enhancing its mechanical strength. The surface morphology, compositions and microstructure of the monolithic coating of HA and nanocomposite coatings of HA with different CNT contents (4 to 25%) on Ti6Al4V were investigated by scanning-electron microscopy, energy-dispersive X-ray spectroscopy and Xray diffractometry, respectively. Electrochemical corrosion behavior of the various coatings in Hanks' solution at 37 degrees C was investigated by means of open-circuit potential measurement and cyclic potentiodynamic polarization tests. Surface hardness, adhesion strength and bone bioactivity of the coatings were also studied. The HA and HA/CNT coatings had a thickness of about 10 microm, with corrosion resistance higher than that of the substrate and adhesion strength higher than that of plasma sprayed HA coating. The properties of the composite coatings were optimized by varying the CNT contents. The enhanced properties could be attributed to the use of nano-sized HA particles and CNTs. Compared with the monolithic HA coating, the CNT-reinforced HA coating markedly increased the coating hardness without deteriorating the corrosion resistance or adhesion strength.

  9. Substrate temperature and strain during sputter deposition of aluminum on cast borosilicate glass in a Gemini Observatory coating chamber.

    Science.gov (United States)

    Sebag, Jacques; Andrew, John; Neill, Douglas; Warner, Michael

    2010-08-20

    Temperature and strain measurements obtained during coating of spin-cast borosilicate samples are presented here with an analysis of these results. These tests were performed for the Large Synoptic Survey Telescope (LSST) project to verify the possible use of sputtering deposition of optical coating on its large 8.4m diameter primary-tertiary mirror. Made of spin-cast borosilicate glass, the working stress of the mirror's nonpolished surfaces is 100 psi (0.69 MPa), resulting in a local temperature difference limit of 5 degrees C. To ensure representative environmental conditions, the tests were performed in the Gemini Observatory coating chamber located in Hawaii, whose design was utilized to develop the LSST coating chamber design. In particular, this coating chamber is equipped with linear magnetrons built with cooled heat shields directly facing the mirror surface. These measurements have demonstrated that it will be safe for the LSST to use a magnetron sputtering process for coating its borosilicate primary-tertiary mirror.

  10. Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

    Energy Technology Data Exchange (ETDEWEB)

    Durmaz, M., E-mail: mdurmaz@sakarya.edu.tr; Abakay, E.; Sen, U.; Sen, S. [Department of Metallurgical and Materials Engineering, Engineering Faculty, Sakarya University, Esentepe Campus, 54187 Sakarya (Turkey); Kilinc, B. [Department of Metallurgical and Materials Engineering, Institute of Arts and Sciences, Sakarya University, Esentepe Campus, 54187 Sakarya (Turkey)

    2015-03-30

    In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr{sub 2}N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV{sub 0.025}. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

  11. Effect of La2O3 Addition on Microstructure and Wear Behavior of Electrospark Deposited Ni-BASED Coatings

    Science.gov (United States)

    Yuxin, Gao; Jian, Yi

    2013-12-01

    La2O3 doped Ni-based coatings have been prepared by electrospark deposition technique. The effect of La2O3 on the microstructure, hardness and wear behavior of the as-prepared Ni-based coatings is investigated by using X-ray diffractometer, scanning electron microscope, wear tribometer and Vickers hardness tester. Results indicates that the microstructure, hardness and wear resistance of La2O3 doped Ni-based coatings are effectively improved as compared to the undoped one, and the coating with the addition of 2.5 wt.% La2O3 shows the optimal improvement effects. The addition of La2O3 can reduce the defects, refine grains and increase hardness of the coating, which can inhibit the nucleation and propagation of cracking, consequently resist cutting and fracture during the wear process. Moreover, the addition of La2O3 leads to changes in abrasion mechanism of the coatings, and the reasons resulting in different abrasion mechanisms are discussed.

  12. Co3O4 protective coatings prepared by Pulsed Injection Metal Organic Chemical Vapour Deposition

    DEFF Research Database (Denmark)

    Burriel, M.; Garcia, G.; Santiso, J.

    2005-01-01

    Cobalt oxide films were grown by Pulsed Injection Metal Organic Chemical Vapour Deposition (PI-MOCVD) using Co(acac)(3) (acac=acetylacetonate) precursor dissolved in toluene. The structure, morphology and growth rate of the layers deposited on silicon substrates were studied as a function...... of deposition temperature. Pure Co3O4 spinel structure was found for deposition temperatures ranging from 360 to 540 degreesC. The optimum experimental parameters to prepare dense layers with a high growth rate were determined and used to prepare corrosion protective coatings for Fe-22Cr metallic interconnects...

  13. Small grain size zirconium-based coatings deposited by magnetron sputtering at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, O., E-mail: omar.jimenez.udg@gmail.com [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, AP 307, CP 45101 Zapopan, Jal (Mexico); Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Audronis, M.; Leyland, A. [Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Flores, M.; Rodriguez, E. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, AP 307, CP 45101 Zapopan, Jal (Mexico); Kanakis, K.; Matthews, A. [Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2015-09-30

    Hard, partly amorphous, ZrTiB(N) coatings were deposited by Physical Vapour Deposition (PVD) onto (111) silicon wafers at low substrate temperatures of 85 and 110 °C using Closed Field Unbalanced Magnetron Sputtering. A segmented rectangular sputter target composed of three pieces (Zr/TiB{sub 2}/Zr) was used as the source of evaporation of coating components. Two different substrate biases (i.e. floating potential and − 50 V) and N{sub 2} reactive-gas flow rates of 2, 4 and 6 sccm were employed as the main deposition parameter variables. The chemical composition, structure, morphology and mechanical properties were investigated using a variety of analytical techniques such as Glow-Discharge Optical Emission Spectroscopy, cross-sectional Scanning Electron Microscopy (SEM), Glancing Angle X-ray Diffraction (GAXRD) and nanoindentation. With other parameters fixed, coating properties were found to be dependent on the substrate negative bias and nitrogen flow rate. Linear scan profiles and SEM imaging revealed that all coatings were smooth, dense and featureless (in fracture cross section) with no apparent columnar morphology or macro-defects. GAXRD structural analysis revealed that mostly metallic phases were formed for coatings containing no nitrogen, whereas a solid solution (Zr,Ti)N single phase nitride was found in most of the reactively deposited coatings — exhibiting a very small grain size due to nitrogen and boron grain refinement effects. Hardness values from as low as 8.6 GPa up to a maximum of 25.9 GPa are related mainly to solid solution strengthening effects. The measured elastic moduli correlated with the trends in hardness behaviour; values in the range of 120–200 GPa were observed depending on the selected deposition parameters. Also, high H/E values (> 0.1) were achieved with several of the coatings.

  14. Some features of ion mixing during simultaneous ion implantation and deposition of metallic coatings

    CERN Document Server

    Pogrebnyak, A D; Mikhalev, A D; Shablya, V T; Yanovskij, V P

    2001-01-01

    The results on the Ta, Cu ions implantation into the aluminium substrate by simultaneous deposition of these ions in the form of coatings are presented. The complex structure of these coatings from the given elements in the substrate, as well as the increase in the microhardness, adhesion and corrosion resistance growth are determined. It is shown on the basis of the results of the secondary ions energy distribution, that intermetallic phases are formed in the substrate surface layer

  15. Characterization of Fe-Cr-B based coatings produced by HVOF and PTA processes

    Science.gov (United States)

    Kim, Hyung-Jun; Grossi, Stephanie; Kweon, Young-Gak

    1999-02-01

    Two Fe-Cr-B based gas atomized powders, Armacor M and 16, were thermally sprayed on a low carbon steel substrate, using the HVOF (High Velocity Oxygen Fuel) process. Armacor M was also weld-surfaced with the PTA (Plasma Transferred Arc) process. The resultant deposits were subsequently characterized, using X-ray diffraction, scanning electron microscopy, and microhardness measurement. The effects of heat treatment were also studied for HVOF-sprayed coatings. The wear performance of the coatings was investigated by two-body abrasive wear tests. The results of microstructural analysis of as-sprayed deposits revealed oxide and boride phases such as Fe3O4 and Cr1.65F0.35B0.96 in an α matrix for the HVOF-sprayed Armacor 16 coating, and only the boride phases (Cr1.65F0.35B0.96 and Cr2B) in an α matrix for the HVOFsprayed Armacor M coating. PTA weld-surfaced Armacor M coating contains needle-type long precipitates of Cr2B) and Cr1.65F0.35B0.96, in the α matrix. The hardness of the HVOF-sprayed Armacor 16 coating after heat treatment was substantially less than that of the as-sprayed coating due to the phase transformation from α to γ phase. Heat treatments of the HVOF-sprayed Armacor M coating did not produce changes in phase and its hardness decreased as compared to that of the as-sprayed coating. While HVOF-sprayed and PTA weld-surfaced Armacor M coatings have the same hardness, the latter shows better abrasive wear resistance because of the size and orientation of its boride phases. The broadening of the XRD patterns and the increase in hardness after wear testing suggest that the transformation from the crystalline to the amorphous structure occurred on the uppermost layer during wear testing.

  16. Electrophoretic co-deposition of polyvinyl alcohol (PVA) reinforced alginate-Bioglass® composite coating on stainless steel: mechanical properties and in-vitro bioactivity assessment.

    Science.gov (United States)

    Chen, Qiang; Cabanas-Polo, Sandra; Goudouri, Ourania-Menti; Boccaccini, Aldo R

    2014-07-01

    PVA reinforced alginate-bioactive glass (BG) composite coatings were produced on stainless steel by a single step electrophoretic deposition (EPD) process. The present paper discusses the co-deposition mechanism of the three components and presents a summary of the relevant properties of the composite coatings deposited from suspensions with different PVA concentrations. Homogeneous composite coatings with compact microstructure and increased thickness, i.e. as high as 10 μm, were observed by scanning electron microscopy (SEM). The surface roughness of coatings with different PVA contents was slightly increased, while a significant increase of water contact angles due to PVA addition was detected and discussed. Improved adhesion strength of coatings containing different amounts of PVA was quantitatively and qualitatively confirmed by pull-off adhesion and cycled bending tests, respectively. In-vitro bioactivity tests were performed in simulated body fluid (SBF) for 0.5, 1, 2, 4, 7, and 14 days, respectively. The decomposition rate of the coatings was reduced with PVA content, and rapid hydroxyapatite forming ability of the composite coatings in SBF was confirmed by FTIR and XRD analyses. According to the results of this study, composite alginate-Bioglass® bioactive coatings combined with PVA are proposed as promising candidates for dental and orthopedic applications.

  17. Structural and corrosion protection properties of electrochemically deposited nano-sized Zn–Ni alloy coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tozar, A., E-mail: tozarali@gmail.com; Karahan, İ.H.

    2014-11-01

    Highlights: • Nano-sized, compact and bright deposits were obtained galvanostatically. • Deposition of zinc–nickel alloys has been materialized in domination of zinc-rich ∂-(Ni{sub 3}Zn{sub 22}) and γ-(Ni{sub 5}Zn{sub 22}) phases. • Sodium citrate (Na{sub 3}C{sub 6}H{sub 5}O{sub 7}) has been used together with boric acid (H{sub 3}BO{sub 3}) for inhibition of instantaneous deposition of zinc and accordingly increasing the relative amount of nickel. • Corrosion protection performances of the deposits were increased with increasing deposition current density and nickel amount. • Crystal defects have been increased with decreasing crystallite size. - Abstract: Zn–Ni alloy coatings were fabricated galvanostatically by applying varied current densities from 10 to 30 mA cm{sup −2}. Surface morphology of the coatings was examined with SEM. Crystal structure of the coatings was studied with X-ray diffraction spectroscopy (XRD). Compositions of the coatings were determined by atomic absorption spectroscopy (AAS). Corrosion protection properties studied using open circuit potential (OCP) measurements, potentiodynamic polarization measurements (Tafel), electrochemical impedance spectroscopy (EIS). Deposited alloy coatings were compact and nano-sized. Crystallite sizes of the coatings were varying from 26 nm to 36 nm. Nickel content of the samples were increased by increasing current densities and varied from 6.7 to 18.9 wt.%. Best corrosion protection performance was seen on the sample obtained at 30 mA cm{sup −2}. Our results are considerably encouraging for protection of mild steel against corrosion by obtained Zn–Ni alloys.

  18. Nano-structured yttria-stabilized zirconia coating by electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maleki-Ghaleh, H., E-mail: H_Maleki@sut.ac.ir [Faculty of Materials Engineering, Sahand University of Technology, Tabriz (Iran, Islamic Republic of); Rekabeslami, M. [Faculty of Mechanical Engineering, Materials Science and Engineering Division, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shakeri, M.S. [Materials and Energy Research Center, Karaj (Iran, Islamic Republic of); Siadati, M.H. [Faculty of Mechanical Engineering, Materials Science and Engineering Division, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Javidi, M. [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Talebian, S.H. [Faculty of Petroleum Engineering, Universiti Technologi Petronas, Perak (Malaysia); Aghajani, H. [Department of Materials Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2013-09-01

    The most important role of thermal barrier coatings is to reduce the temperature of the substrate in high temperature applications. Nanoparticle zirconia might be a suitable choice for improving the efficiency of thermal barrier coatings. Nanostructured coatings have lower thermal conduction, higher thermal expansion and lower dimensional variations at higher temperatures in comparison with the microstructured coatings. Electrophoretic deposition has been preferred for thermal barrier coatings due to its simplicity, controllability and low cost. In the present study, three different suspensions of ZrO{sub 2}–8 wt%Y{sub 2}O{sub 3} (40 nm) made with ethanol, acetone and acetyl acetone were used. Electrophoretic deposition was conducted at a fixed voltage of 60 V for 120 s on aluminized Inconel 738-LC, and then heat treated at 1100{sup o}C for 4 h in air atmosphere. The coating morphology and elemental distribution were studied using scanning electron microscopy. It was observed that suspension media have an important effect on the quality of the final product. Acetyl acetone showed better dispersion of particles than the other two media. Consequently, deposition from acetyl acetone resulted in uniform and crack-free layers while those from ethanol and acetone were completely non-uniform due to agglomeration and low viscosity, respectively.

  19. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel.

    Science.gov (United States)

    Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO4·H2O; HA, Ca10(PO4)6(OH)2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO3)2·4H2O and NH4H2PO4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50°C for all deposition times, while at 25°C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance.

  20. Microstructure evolution of cold-sprayed coating during deposition and through post-spraying heat treatment

    Institute of Scientific and Technical Information of China (English)

    LI Chang-jiu; LI Wen-ya

    2004-01-01

    The microstructural features of cold-sprayed coatings were investigated using Cu, Ti and Zn feedstocks by optical microscopy, scanning electron microscopy and transmission electron microscopy to reveal the microstructure evolution mechanisms in cold spray. Four typical effects including tamping, refinement, impact-induced fusion and annealing were examined on microstrueture. It is found that the microstructure of cold spray coating is remarkably influenced by spray materials. Ti coatings consist of evident porous layer and Cu coatings present a limited porous layer only near the surface. It is clear that the successive tamping effect and dynamic refinement of grains significantly influence the microstructure evolution of cold-sprayed coating. The tamping effect leads to the densification of porous coating layer gradually and the refinement effect leads to the formation of fine microstructure. It is considered that the large difference in the formation of porous layer is attributed to the dynamic impact pressure and hardenability of materials. It is also found that the impact-induced fusion during deposition of Zn coating can also modify the interfacial microstructure between particles in cold spray coating. Moreover, the nanocrystalline phase can be formed at the interfaces among particles resulting from the localized melting of the interfaces and tamping effect. Furthermore, the annealing treatment can modify the microstructure and property of a cold-sprayed coating.

  1. Quantitative Image Analysis of Ni-P Coatings Deposited on Carbon Fibers

    Science.gov (United States)

    Kozera, R.; Bucki, J. J.; Sałacińska, A.; Bieliński, J.; Boczkowska, A.

    2015-09-01

    In this work, polyacrylonitrile (PAN)-based carbon fibers coated with different thicknesses of Ni-P coatings were studied. The coatings were deposited by electroless metallization lasting from 3 to 22 min and consisted of approximately 3 wt.% phosphorous. Computer quantitative image analysis was used to characterize the surface features and thickness of the coatings as a function of the time of metallization. The results showed that quantitative image analysis is a useful technique for the measurement of the coating thickness and can be used as a tool for obtaining an innovative description of the Ni-P coating morphology. The morphology of the coatings and their thicknesses were investigated by scanning electron microscopy. The image analyses were performed using the proprietary software Micrometer, developed at the Faculty of Materials Science and Engineering, Warsaw University of Technology. The observations revealed that a specific feature of the coating topography is the hemispherical bulge of a diameter ranging from 0.1 to 10 μm. The thickness of the coatings increases linearly with the metallization time. The obtained results indicated that the methodology proposed in the present work can be successfully applied and possesses several advantages over the traditionally used weight measurements technique.

  2. Anodisation of sputter deposited aluminium–titanium coatings: Effect of microstructure on optical characteristics

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Junker-Holst, Andreas; Vestergaard Nielsen, Daniel;

    2014-01-01

    -ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES), while the optical appearance was investigated using photospectrometry. The microstructure of the coatings was varied by heat treatment, resulting in the precipitation of Al3Ti phases. The reflectance of the anodised surfaces...... decreasedwith titaniumcontent in the as-deposited, and heat-treated states, and after anodisation of the as-deposited coatings. Specimens turned grey or blackwhen anodising after heat treatment. Partially anodised Al3Ti phaseswere found in the anodised layer, and the interface between substrate and anodised...

  3. Preparation and characterization of YBCO coating on metallic RABiT substrates by pulsed laser deposition

    Science.gov (United States)

    Gonal, M. R.; Prajapat, C. L.; Igalwar, P. S.; Maji, B. C.; Singh, M. R.; Krishnan, M.

    2016-05-01

    Superconducting YBCO films are coated on metallic Rolling Assisted Bi-axially Textured Substrates (RABiTS) Ni-5wt % W (NiW) (002) substrate using pulsed laser deposition (PLD) system. Targets of YBa2Cu3O7-δ (YBCO) and buffer layers of Ceria and 8 mole % Yttria Stabilized Zirconia (YSZ) of high density are synthesized. At each stage of deposition coatings are characterized by XRD. Transport studies show superconducting nature of YBCO only when two successive buffer layers of YSZ and CeO2 are used.

  4. Microanalyses of the hydroxyl—poly—calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    LIUZhong-Yang; WANGChang-Xing; 等

    2002-01-01

    Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar+ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.

  5. Morphology and microstructure evolution of Ti-50 at.% Al cathodes during cathodic arc deposition of Ti-Al-N coatings

    Science.gov (United States)

    Syed, Bilal; Zhu, Jianqiang; Polcik, Peter; Kolozsvari, Szilard; Hâkansson, Greger; Johnson, Lars; Ahlgren, Mats; Jöesaar, Mats; Odén, Magnus

    2017-06-01

    Today's research on the cathodic arc deposition technique and coatings therefrom primarily focuses on the effects of, e.g., nitrogen partial pressure, growth temperature, and substrate bias. Detailed studies on the morphology and structure of the starting material—the cathode—during film growth and its influence on coating properties at different process conditions are rare. This work aims to study the evolution of the converted layer, its morphology, and microstructure, as a function of the cathode material grain size during deposition of Ti-Al-N coatings. The coatings were reactively grown in pure N2 discharges from powder metallurgically manufactured Ti-50 at.% Al cathodes with grain size distribution averages close to 1800, 100, 50, and 10 μm, respectively, and characterized with respect to microstructure, composition, and mechanical properties. The results indicate that for the cathode of 1800 μm grain size the disparity in the work function among parent phases plays a dominant role in the pronounced erosion of Al, which yields the coatings rich in macro-particles and of high Al content. We further observed that a reduction in the grain size of Ti-50 at.% Al cathodes to 10 μm provides favorable conditions for self-sustaining reactions between Ti and Al phases upon arcing to form γ phase. The combination of self-sustaining reaction and the arc process not only result in the formation of hole-like and sub-hole features on the converted layer but also generate coatings of high Al content and laden with macro-particles.

  6. Preparation of superhydrophobic silver nano coatings with feather-like structures by electroless galvanic deposition

    Institute of Scientific and Technical Information of China (English)

    FENG XiaoJuan; SHI YanLong; WANG YongSheng; YUE GuoRen; YANG Wu

    2013-01-01

    Superhydrophobic silver nanocoatings with feather-like morphology are fabricated on copper substrates by electroless galvanic deposition.The coating exhibit superhydrophobicity with a contact angle of 156.4° and glide angle of 4° without any further surface modification.Scanning electron microscope (SEM),X-ray diffraction (XRD) and contact angle measurements are used to investigate the morphology,crystal structure and superhydrophobicity,respectively,of the coatings.The coatings exhibit high thermal stability; their water contact angle did not change when the coatings were heated to 200℃ for 2 h.The mechanism of superhydrophobicity of the silver coating is discussed based on the work of Amirfazli,Wenzel and Cassie.

  7. Characteristics of copper meshes coated with carbon nanotubes via electrophoretic deposition

    Science.gov (United States)

    Kim, Bu-Jong; Park, Jong-Seol; Hwang, Young-Jin; Park, Jin-Seok

    2016-09-01

    This study demonstrates the characteristics of a hybrid-type transparent electrode for touch screen panels, which was fabricated by coating carbon nanotubes (CNTs) via electrophoretic deposition (EPD) on copper (Cu)-meshes. The surface morphologies, visible-range transmittance and reflectance, and chromatic properties, such as yellowness and redness, of the fabricated CNTs-coated Cu mesh electrodes were characterized as functions of their dimensions (line-to-line spacing, line width, and electrode thickness) and compared with those of the Cu-mesh electrodes without coating of CNTs. The experimental results showed that the coating of CNTs substantially reduced the reflectance of the Cu-mesh electrodes and also improved their chromatic properties with their transmittance and sheet resistance only slightly changed, subsequently indicating that the CNTs-coated Cu-mesh electrodes possessed desirable characteristics for touch screen panels.

  8. Investigation on the corrosion behavior of physical vapor deposition coated high speed steel

    Directory of Open Access Journals (Sweden)

    R Ravi Raja Malarvannan

    2015-08-01

    Full Text Available This work emphasizes on the influence of the TiN and AlCrN coatings fabricated on high speed steel form tool using physical vapor deposition technique. The surface microstructure of the coatings was studied using scanning electron microscope. Hardness and corrosion studies were also performed using Vickers hardness test and salt spray testing, respectively. The salt spray test results suggested that the bilayer coated (TiN- bottom layer and AlCrN- top layer substrate has undergone less amount of corrosion, and this is attributed to the dense microstructure. In addition to the above, the influence of the above coatings on the machining performance of the high speed steel was also evaluated and compared with that of the uncoated material and the results suggested that the bilayered coating has undergone very low weight loss when compared with that of the uncoated substrate depicting enhanced wear resistance.

  9. Studies on non-oxide coating on carbon fibers using plasma enhanced chemical vapor deposition technique

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Prajapati, K. K.; Vyas, M. M.; Batra, N. M.

    2016-05-01

    A new way of improving the oxidative behavior of carbon fibers coated with SiC through Plasma Enhanced Chemical Vapor Deposition technique. The complete study includes coating of SiC on glass slab and Stainless steel specimen as a starting test subjects but the major focus was to increase the oxidation temperature of carbon fibers by PECVD technique. This method uses relatively lower substrate temperature and guarantees better stoichiometry than other coating methods and hence the substrate shows higher resistance towards mechanical and thermal stresses along with increase in oxidation temperature.

  10. Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films — Coating characterization and first cell biological results

    Energy Technology Data Exchange (ETDEWEB)

    Strąkowska, Paulina [Gdańsk University of Technology, Mechanical Engineering Faculty (Poland); Gdańsk University of Technology, Faculty of Electronics, Telecommunications, and Informatics (Poland); Beutner, René [Max Bergmann Center, Technische Universität Dresden (Germany); Gnyba, Marcin [Gdańsk University of Technology, Faculty of Electronics, Telecommunications, and Informatics (Poland); Zielinski, Andrzej [Gdańsk University of Technology, Mechanical Engineering Faculty (Poland); Scharnweber, Dieter, E-mail: Dieter.Scharnweber@tu-dresden.de [Max Bergmann Center, Technische Universität Dresden (Germany)

    2016-02-01

    Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD > HAp/B-NCD > uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

  11. Drop coating deposition Raman (DCDR) for microcystin-LR identification and quantitation.

    Science.gov (United States)

    Halvorson, Rebecca A; Vikesland, Peter J

    2011-07-01

    A drop coating deposition Raman (DCDR) method was developed for the analysis of 2-200 ng samples of microcystin-LR (MC-LR), a ubiquitous and deadly hepatotoxin secreted by cyanobacteria. Solid phase extraction (SPE) of the toxin from a water sample enabled identification of MC-LR at 5 μg/L to 100 mg/L concentrations, and the collected results suggest lower detection limits can be readily attained following DCDR substrate modification. The DCDR process was applied to aqueous sample volumes of 0.5-20 μL that generated sample deposits from which MC-LR Raman spectra could be obtained within seconds. Larger volume samples were not required to improve spectral resolution. Volumes of 2 μL were ideal, producing "coffee-ring" MC-LR deposits that displayed distinct MC-LR Raman signals with high signal-to-noise within 1 s for a 200 ng sample and 300 s for a 2 ng sample. A linear correlation between Raman signal intensity and concentration was observed for 2-100 ng MC-LR samples after signal normalization. Reproducible MC-LR Raman spectra were collected from both fresh and aged samples. The presence of dissolved organic matter (DOM) did not preclude MC-LR identification in DCDR deposits of 3 μg of DOM mixed with 0.7 μg of MC-LR. Application of DCDR to environmental samples will require sample purification such as SPE before analysis, including critical cartridge wash and toxin rinsing steps. Raman based methods may one day facilitate simpler and faster sample throughput than traditional MC-LR detection methods.

  12. Electrochemical Study of Ni20Cr Coatings Applied by HVOF Process in ZnCl2-KCl at High Temperatures

    Science.gov (United States)

    Porcayo-Calderón, J.; Sotelo-Mazón, O.; Casales-Diaz, M.; Ascencio-Gutierrez, J. A.; Salinas-Bravo, V. M.; Martinez-Gomez, L.

    2014-01-01

    Corrosion behavior of Ni20Cr coatings deposited by HVOF (high velocity oxygen-fuel) process was evaluated in ZnCl2-KCl (1 : 1 mole ratio) molten salts. Electrochemical techniques employed were potentiodynamic polarization curves, open circuit potential, and linear polarization resistance (LPR) measurements. Experimental conditions included static air and temperatures of 350, 400, and 450°C. 304-type SS was evaluated in the same conditions as the Ni20Cr coatings and it was used as a reference material to assess the coatings corrosion resistance. Coatings were evaluated as-deposited and with a grinded surface finished condition. Results showed that Ni20Cr coatings have a better corrosion performance than 304-type SS. Analysis showed that Ni content of the coatings improved its corrosion resistance, and the low corrosion resistance of 304 stainless steel was attributed to the low stability of Fe and Cr and their oxides in the corrosive media used. PMID:25210645

  13. [An investigation of HAP/organic polymer composite coatings prepared by electrochemical co-deposition technique].

    Science.gov (United States)

    Hu, Haobing; Lin, Changjian; Leng, Yang

    2003-03-01

    An electrochemical co-deposition technique has been developed to prepare a hydroxyapatite (HAP)/organic polymer composite coatings on Ti surface as new biomaterial of hard tissue. The composite coating of organic polymer and calcium phosphate is formed by adding a water soluble polymer of the ethylene series to NH4H2PO4-Ca (NO3)2 solution when conducting an appropriate electrochemical co-deposition experiment. The XRD, SEM, XPS, SIMS and nano indent measurements were performed to characterize the morphology, composition, structure and surface stiffness of the composite coating. It was found that the morphology and surface hardness of the coatings showed a remarkable modification when introducing a minor polymer to HAP coating, and the bonding force between the coating and metal substrate was distinctly increased. The incorporation of minor organic polymer into the HAP compound at molecular level will improve the mechanical properties and morphology of the composite coatings, and this may be helpful to raising its bio-activity.

  14. In Situ Synthesis and Characterization of Fe-Based Metallic Glass Coatings by Electrospark Deposition Technique

    Science.gov (United States)

    Burkov, Alexander A.; Pyachin, S. A.; Ermakov, M. A.; Syuy, A. V.

    2017-02-01

    Crystalline FeWMoCrBC electrode materials were prepared by conventional powder metallurgy. Metallic glass (MG) coatings were produced by electrospark deposition onto AISI 1035 steel in argon atmosphere. X-ray diffraction and scanning electron microscopy verified the amorphous structure of the as-deposited coatings. The coatings have a thickness of about 40 microns and a uniform structure. The results of dry sliding wear tests against high-speed steel demonstrated that Fe-based MG coatings had a lower friction coefficient and more than twice the wear resistance for 20 km sliding distance with respect to AISI 1035 steel. High-temperature oxidation treatment of the metal glass coatings at 1073 K in air for 12 h revealed that the oxidation resistance of the best coating was 36 times higher than that for bare AISI 1035 steel. These findings are expected to broaden the applications of electrospark Fe-based MG as highly protective and anticorrosive coatings for mild steel.

  15. PREPARING OF THE CHAMELEON COATING BY THE ION JET DEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    Jakub Skocdopole

    2017-07-01

    Full Text Available Preparation of chameleon coatings using an Ionized Jet Deposition (IJD technique is reported in the present paper. IJD is a new flexible method for thin film deposition developed by Noivion, Srl. The chameleon coatings are thin films characterised by a distinct change of their tribological properties according to the external conditions. The deposited films of SiC and TiN materials were examined by the Raman spectroscopy, SEM and XPS. The results of the Raman spectroscopy have proved an amorphous structure of SiC films. The data from XPS on TiN films have shown that the films are heavily oxidized, but also prove that the films are composed of TiN and pure Ti. The SEM provided information about the size of grains and particles constituting the deposited films, which is important for tribological properties of the films. Deposition of the chameleon coating is very complex problem and IJD could be ideal method for preparation of this coating.

  16. Aluminizing Coating and Aluminizing-Y2O3 Coating Deposited by Pulsed Spark

    Institute of Scientific and Technical Information of China (English)

    何业东; 黄祖芬; 王德仁; 齐惠滨; 高 高唯

    2001-01-01

    Aluminizing coating and aluminizing-dispersed Y2O3 composite coating were prepared on 20 steel specimens by pulsed spark technique, which exhibited a micro-crystallized structure with grain size in the range of several ten to several hundred nanometers. It is shown that, after oxidation at 600 ℃ in air for 100 h, these two kinds of coatings have excellent resistance to high temperature oxidation and scale spallation, and the aluminizing-dispersed Y2O3 composite coating has even better property than the aluminizing coating. AFM, SEM, EDS and XRD were applied to analyze the surface morphology, composition and phases structure of these coatings and the oxide scale formed in oxidation. The mechanism for these coatings that how to enhance the oxidation resistance and scale spallation resistance was discussed by considering the factors, such as Al concentration on the selective oxidation of Fe-Al alloy, the effect of micro-crystallization, reactive element effect (REE) caused by dispersed Y2O3, etc.

  17. The Electro-Spark Deposited WC-Cu Coatings Modified by Laser Treatment / Powłoki WC-Cu Naniesione Elektroiskrowo I Modyfikowane Obróbką Laserową

    OpenAIRE

    Radek N.; Konstanty J.; Scendo M.

    2015-01-01

    The main objective of the present work was to determine the influence of laser treatment on microstructure, X-ray diffraction, microhardness, surface geometric structure and roughness, corrosion resistance and tribological properties of coatings deposited on C45 carbon steel by the electro-spark deposition (ESD) process. The studies were conducted using WC-Cu electrodes produced by the powder metallurgy route. The tests show that the laser-treated electro-spark deposited WC-Cu coatings are ch...

  18. Deposition and characterization of diamond-like nanocomposite coatings grown by plasma enhanced chemical vapour deposition over different substrate materials

    Indian Academy of Sciences (India)

    Awadesh Kr Mallik; Nanadadulal Dandapat; Prajit Ghosh; Utpal Ganguly; Sukhendu Jana; Sayan Das; Kaustav Guha; Garfield Rebello; Samir Kumar Lahiri; Someswar Datta

    2013-04-01

    Diamond-like nanocomposite (DLN) coatings have been deposited over different substrates used for biomedical applications by plasma-enhanced chemical vapour deposition (PECVD). DLN has an interconnecting network of amorphous hydrogenated carbon and quartz-like oxygenated silicon. Raman spectroscopy, Fourier transform–infra red (FT–IR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) have been used for structural characterization. Typical DLN growth rate is about 1 m/h, measured by stylus profilometer. Due to the presence of quartz-like Si:O in the structure, it is found to have very good adhesive property with all the substrates. The adhesion strength found to be as high as 0.6 N on SS 316 L steel substrates by scratch testing method. The Young’s modulus and hardness have found to be 132 GPa and 14.4 GPa, respectively. DLN coatings have wear factor in the order of 1 × 10-7 mm3/N-m. This coating has found to be compatible with all important biomedical substrate materials and has successfully been deposited over Co–Cr alloy based knee implant of complex shape.

  19. Process Heating and Postannealing Effects on Microstructure and Hardness of the Sputtered Ni-P-Al Coatings

    Directory of Open Access Journals (Sweden)

    Yu-Ming Su

    2011-01-01

    Full Text Available Ternary Ni-P-Al alloy coating was fabricated by magnetron sputtering technique with a Ni-P/Al composite target source. The effects of thermal treatments, including deposition process heating and postannealing, on phase transformation phenomenon and related mechanical properties were investigated. The as-deposited coatings produced under process temperature below 475∘C showed an amorphous/nanocrystalline microstructure. Significant crystallization of Ni matrix and precipitation of NiP and NiAl compounds were observed for the coatings manufactured under high sputtering temperatures above 500∘C. The amorphous Ni-P-Al coatings were postannealed from 500 to 600∘C in vacuum environment for comparison. The amorphous feature of the Ni-P-Al coating remained unchanged under a high annealing temperature of 550∘C, showing a superior thermal stability as compared to those fabricated under high process temperatures. Superior hardness was obtained for the post-annealed Ni-P-Al coatings due to volumetric constraint of crystallization and precipitation. On the other hand, the overaging phenomenon and subsequent degradation in hardness were found for the Ni-P-Al coatings fabricated under high-temperature deposition processes. The phase transformation mechanisms of the coatings through different thermal treatments were intensively discussed.

  20. Lithographic deposition of patterned metal-organic framework coatings using a photobase generator.

    Science.gov (United States)

    Keitz, Benjamin K; Yu, Chung Jui; Long, Jeffrey R; Ameloot, Rob

    2014-05-26

    A photobase generator was used to induce metal-organic framework (MOF) nucleation upon UV irradiation. This method was further developed into a simple, one-step method for depositing patterned MOF films. Furthermore, the ability of our method to coat a single substrate with MOF films having different chemical compositions is illustrated. The method is an important step towards integrating MOF deposition with existing lithographic techniques and the incorporation of these materials into sensors and other electronic devices.

  1. New Approach to Depositing Yttria-Stabilized Zirconia Buffer Layers for Coated Conductors (Postprint)

    Science.gov (United States)

    2012-02-01

    YBa2Cu3O7− ( YBCO ) cannot be deposited directly onto the tapes due to tape oxidation and chemical interdiffu- sion issues,5 so buffer layers must be used... YBCO can be deposited. Control of the biaxial texture of the final YBCO superconducting layer is critical to the success of the YBCO -coated conductor...Misorientation at YBCO grain boundaries, both [100]-tilt and [100]-twist, have a significant impact on critical cur- rent density (Jc); nearly an

  2. Controlled Deposition and Performance Optimization of Perovskite Solar Cells Using Ultrasonic Spray-Coating of Photoactive Layers.

    Science.gov (United States)

    Chang, Wei-Chieh; Lan, Ding-Hung; Lee, Kun-Mu; Wang, Xiao-Feng; Liu, Cheng-Liang

    2016-12-27

    This study investigated a new film-deposition technique, ultrasonic spray-coating, for use in the production of a photoactive layer of perovskite solar cells. Stable atomization and facile fabrication of perovskite thin films by ultrasonic spray-coating were achieved in a one-step method through manipulating the ink formulation (e.g., solution concentration, precursor composition, and mixing solvent ratio) and the drying kinetics (e.g., post-annealing temperature). The performance of the perovskite solar cells was mainly influenced by the intrinsic film morphology and crystalline orientation of the deposited perovskite layer. By suitable optimization of the spreading and drying conditions of the ink, ultrasonic spray-coated perovskite photovoltaic devices were obtained with a maximum power conversion efficiency of 11.30 %, a fill factor of 73.6 %, a short-circuit current of 19.7 mA cm(-1) , and an open-circuit voltage of 0.78 V, respectively. Notably, the average power efficiency reached above 10 %, attributed to the large flower-like perovskite crystal with orientation along the (1 1 2)/(2 0 0) and (2 2 4)/(4 0 0) directions. Thus, the ultrasonic spray-coating method for perovskite photoactive layers, combining advantages of good photovoltaic performance results and benefits from cost and processing, has the potential for large-scale commercial production.

  3. Electrospark deposition of Al2O3–TiB2/Ni composite-phase surface coatings on Cu–Cr–Zr alloy electrodes

    OpenAIRE

    Ping Luo; Shijie Dong; Anzhuo Yangli; Shixuan Sun; Zhong Zheng; Huihu Wang

    2015-01-01

    To improve electrode life during the resistance spot welding of galvanized steel plates, an Al2O3–TiB2 composite coating was synthesized on the surfaces of spot-welding electrodes through an electrospark deposition process. The microstructure, elemental composition, phase structure, and mechanical properties of the coating were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and microhardness testing. It was found that extens...

  4. Tungsten coatings electro-deposited on CFC substrates from oxide molten salt

    Science.gov (United States)

    Sun, Ningbo; Zhang, Yingchun; Lang, Shaoting; Jiang, Fan; Wang, Lili

    2014-12-01

    Tungsten is considered as plasma facing material in fusion devices because of its high melting point, its good thermal conductivity, its low erosion rate and its benign neutron activation properties. On the other hand, carbon based materials like C/C fiber composites (CFC) have been used for plasma facing materials (PFMs) due to their high thermal shock resistance, light weight and high strength. Tungsten coatings on CFC substrates are used in the JET divertor in the frame of the JET ITER-like wall project, and have been prepared by plasma spray (PS) and other techniques. In this study, tungsten coatings were electro-deposited on CFC from Na2WO4-WO3 molten salt under various deposition parameters at 900 °C in air. In order to obtain tungsten coatings with excellent performance, the effects of pulse duration ratio and pulse current density on microstructures and crystal structures of tungsten coatings were investigated by X-ray diffraction (XRD, Rigaku Industrial Co., Ltd., D/MAX-RB) and a scanning electron microscope (SEM, JSM 6480LV). It is found that the pulsed duration ratio and pulse current density had a significant influence on tungsten nucleation and electro-crystallization phenomena. SEM observation revealed that intact, uniform and dense tungsten coatings formed on the CFC substrates. Both the average grain size and thickness of the coating increased with the pulsed current density. The XRD results showed that the coatings consisted of a single phase of tungsten with the body centered cubic (BCC) structure. The oxygen content of electro-deposited tungsten coatings was lower than 0.05%, and the micro-hardness was about 400 HV.

  5. Surface enhanced Raman spectroscopy on silver-nanoparticle-coated carbon-nanotube networks fabricated by electrophoretic deposition

    Science.gov (United States)

    Sarkar, Anirban; Wang, Hao; Daniels-Race, Theda

    2014-03-01

    In this study, the efficiency of silver nanoparticle (AgNP) decorated carbon nanotube (CNT) based porous substrates has been investigated for surface-enhanced Raman spectroscopy (SERS) applications. The fabrication of uniform thin coatings of carbon nanotubes is accomplished by Electrophoretic Deposition (EPD) on organosilane functionalized silicon substrates. The deposition process exemplifies a fast, reproducible and single-step room temperature coating strategy to fabricate horizontally aligned porous CNT network. Surfactant stabilized AgNPs were deposited on the CNT networks by immersion coating. The acquired Raman spectra of Rhodamine6G (R6G) analyte examined on the fabricated Ag-CNT-Si substrates exhibited enhanced signal intensity values when compared to SERS-active planar AgNP-Si substrates. An overall enhancement factor of ˜109 was achieved for the tested analyte which enables pushing the limit of detection to 1 × 10-12 M (1 pM). The enhancement can be attributed to the large surface area offered by the AgNP-CNT porous network, which is expected to increase the number of effective "hot spots" for the SERS effect.

  6. New types of coating systems for steel sheets by high-rate evaporation in combination with plasma processes

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, B.; Metzner, C. [Fraunhofer-Institut fuer Elektronenstrahl und Plasmatechnik (FEP), Dresden (Germany); Ehlers, K.D. [Salzgitter AG Stahl und Technologie (Germany); Schuhmacher, B. [Dortmunder Oberflaechencentrum GmbH, Dortmund (Germany); Flossdorf, F.J.; Steinbeck, G. [Verein Deutscher Eisenhuettenleute (VDEh), Duesseldorf (Germany); Steffen, R. [Stahlwerke Bremen GmbH (Germany); Hagler, J. [voestalpine Stahl GmbH, Linz (Austria)

    2002-03-01

    High-rate evaporation in combination with plasma processes is a promising approach to obtain new types of steel sheet coating with improved corrosion resistance and application properties. To estimate the potential for the application of PVD-coatings (physical vapour deposition) different coating systems for steel sheet as well as for hot-dip or electro-galvanized steel sheet were designed. The samples were produced on a laboratory scale using PVD processes with very high deposition rates (in the order of 1 {mu}m s{sup -1}) as well as high-power plasma processes for the pre-treatment. The relationship between the composition, microstructure and properties of the coating systems, in particular concerning corrosion protection, abrasion during forming, phosphating and paint adhesion, were studied. It was found that the corrosion resistance of galvanized steel sheets can be considerably improved by vapour deposition of metal or inorganic films with a thickness of several hundred nanometers. Investigations on vapour deposition of titanium and stainless steel coatings on steel sheets, for applications in a severely corrosive environment, showed that the corrosion resistance in relation to the coating thickness can be significantly enhanced by means of plasma activation during the vapour deposition process. Finally, an outlook on possible industrial applications including an estimation of the process costs will be presented. For certain coating systems the results look promising. Consequently, these particular coating systems will be investigated in more detail by means of using a large-scale in-line deposition plant for metallic strips and sheets. (orig.)

  7. Effect of the addition CNTs on performance of CaP/chitosan/coating deposited on magnesium alloy by electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Pharmaceutical Research Institute in Heilongjiang Province, Jiamusi University, Jiamusi 154007 (China); Wen, Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zhao, Meng [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Guozhong, E-mail: hydlgz1962@163.com [Department of Neuro Intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Dai, Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)

    2016-01-01

    CaP/chitosan/carbon nanotubes (CNTs) coating on AZ91D magnesium alloy was prepared via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The bonding between the layer and the substrate was studied by an automatic scratch instrument. The phase compositions and microstructures of the composite coatings were determined by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM). The element concentration and gentamicin concentration were respectively determined by inductively coupled plasma optical emission spectrometer (ICP-OES) test and ultraviolet spectrophotometer (UV). The cell counting kit (CCK) assay was used to evaluate the cytotoxicity of samples to SaOS-2 cells. The results showed that a few CNTs with their original tubular morphology could be found in the CaP/chitosan coating and they were beneficial for the crystal growth of phosphate and improvement of the coating bonding when the addition amount of CNTs in 500 ml of electrophoretic solution was from 0.05 g to 0.125 g. The loading amount of gentamicin increased and the releasing speed of gentamicin decreased after CNTs was added into the CaP/chitosan coating for immersion loading and EPD loading. The cell viability of Mg based CaP/chitosan/CNTs was higher than that of Mg based CaP/chitosan from 16 days to 90 days. - Highlights: • CaP/chitosan/CNTs coating on AZ91D was prepared. • The addition of CNTs could improve the performance of CaP/chitosan coating. • A new method of loading gentamicin by EPD was proposed.

  8. Anodized porous titanium coated with Ni-CeO2 deposits for enhancing surface toughness and wear resistance

    Science.gov (United States)

    Zhou, Xiaowei; Ouyang, Chun

    2017-05-01

    In order to make large improvements of surface toughness and wear resistance for pure titanium (Ti) substrate, anodic titanium oxide (ATO) surface with nanoporous structure was coated with the Ni-CeO2 nanocomposite coatings. Regarding TiO2 barrier layer on Ti surface to inhibit its electrochemical activity, pre-treatments were successively processed with anodizing, sensitizing, activating, and then followed by electroless Ni-P film to be acted as an activated layer for electroplating Ni-CeO2 deposits. The existing Pd atoms around ATO nanopores were expected as the heterogeneous nucleation sites for supporting the growing locations of electroless Ni-P film. The innovative of interface design using porous structure was introduced for bonding pinholes to achieve a metallurgical adhesion interface between Ti substrate and surface coatings. Besides the objectives of this work were to elucidate how effects by the adding CeO2 nanoparticles on modifying microstructures and wear mechanisms of Ni-CeO2 nanocomposite coatings. Many efforts of XRD, FE-SEM, TEM and Nanoindentation tests were devoted to comparing different wear behaviors of Ni-CeO2 coatings relative to pure nickel. Results indicated that uniform-distributed Ti nanopores with an average diameter size of ∼200 nm was achieved using the Phosphate-type anodizing solution at DC 150 V. A worn surface without fatigue cracks was observed for TAO surface coated with Ni-CeO2 deposits, showing the existing Ce-rich worn products to be acted as a solid lubricant phase for making a self-healing effect on de-lamination failures. More important, this finding will be the guidelines for Ce-rich precipitations to be expected as the strengthening phase in anodized porous of Ti, Al and Mg alloys for intensifying their surface properties.

  9. Parameters influencing polymer particle layering of the dry coating process.

    Science.gov (United States)

    Kablitz, Caroline Désirée; Kappl, Michael; Urbanetz, Nora Anne

    2008-06-01

    The dry coating process is an emerging coating technology using neither organic solvents nor water. In contrast to liquid-borne coatings, coating material application and film formation are divided into two phases, the coating phase where the powdery coating material is applied together with the liquid plasticizer, and the curing phase. In this study the coating phase was characterized with respect to the forces acting between the polymer particles during material application. Atomic force microscopy was conducted measuring the interparticle forces which were related to the coating efficiency. The influence of different liquid additives on the interparticle forces and the coating efficiency were evaluated. HPMCAS was used as enteric resistant polymer, triethylcitrate (TEC), Myvacet (diacetylated monoglyceride) and a mixture of both as liquid additives. Interparticle forces were found to be similar when using TEC or a mixture of TEC and Myvacet. In contrast, interparticle forces were higher when using solely Myvacet. This is attributed to the fact that Myvacet does not penetrate into the polymer without TEC which is acting as a penetration enhancer. As Myvacet remains predominantly on the particle surface, capillary forces act between the particles explaining high interparticle forces. The highest interparticle force determined by AFM is in accordance to the highest coating efficiency which has been found for the corresponding coating formulation containing HPMCAS and Myvacet. Consequently, it is demonstrated that the ability of the liquid to remain on the surface of the polymer and to build up capillary forces is crucial for the material application.

  10. Microstructural Evolution of (Ti,W,CrB2 Coatings Deposited on Steel Substrates during Annealing

    Directory of Open Access Journals (Sweden)

    Aleksandra Newirkowez

    2014-05-01

    Full Text Available The topic of the present experiments are transition metal diboride coatings of composition (Ti0.49W0.51B2 and (Ti0.44W0.30Cr0.26B2. The coatings were deposited on steel substrates using dc magnetron sputtering. We investigated how annealing in argon at elevated temperatures modifies microstructure. The as-deposited films are amorphous. Annealing between 700 and 1100 °C results in the formation of nano-crystalline precipitates with average grain diameters of about 10–50 nm. A TiC phase (Fm-3m; a ≈ 4.3 Å is observed as the dominating precipitate phase. In addition, small amounts (10%–20% of a Cr23C6 phase (Fm-3m; a ≈ 10.6 Å are observed. In contrast to literature data on the same coatings deposited on silicon substrates, the formation of boride precipitate phases is strongly suppressed here. From investigations with X-ray diffractometry, electron microscopy and secondary ion mass spectrometry we conclude that the nanostructure of the coatings is formed by reactive phase formation of the boride coating with the carbon containing steel substrate.

  11. The Electro-Spark Deposited WC-Cu Coatings Modified by Laser Treatment / Powłoki WC-Cu Naniesione Elektroiskrowo I Modyfikowane Obróbką Laserową

    Directory of Open Access Journals (Sweden)

    Radek N.

    2015-12-01

    Full Text Available The main objective of the present work was to determine the influence of laser treatment on microstructure, X-ray diffraction, microhardness, surface geometric structure and roughness, corrosion resistance and tribological properties of coatings deposited on C45 carbon steel by the electro-spark deposition (ESD process. The studies were conducted using WC-Cu electrodes produced by the powder metallurgy route. The tests show that the laser-treated electro-spark deposited WC-Cu coatings are characterized by higher corrosion resistance, surface roughness and seizure resistance which come at the expense of lower microhardness. The laser treatment process causes the homogenization of the chemical composition, structure refinement and healing of microcracks and pores of the electro-spark deposited coatings. Laser treated ESD coatings can be applied in sliding friction pairs and as protective coatings.

  12. Mechanical stability of two-step chemically deposited hydroxyapatite coating on Ti substrate: effects of various surface pretreatments.

    Science.gov (United States)

    Zavgorodniy, Alexander V; Borrero-López, Oscar; Hoffman, Mark; LeGeros, Racquel Z; Rohanizadeh, Ramin

    2011-10-01

    The success of implants in orthopaedic and dental load-bearing applications crucially depends on the initial biological fixation of implants in surrounding bone tissues. Using hydroxyapatite (HA) coating on Ti implant as carrier for bone morphogenetic proteins (BMPs) may promote the osteointegration of implants; therefore, reduce the risk of implant failure. The goal of this study was to develop an HA coating method in conditions allowing the incorporation of protein-based drugs into the coating materials, while achieving a mechanical stable coating on Ti implant. HA coatings were deposited on six different groups of Ti surfaces: control (no pretreatment), pretreated with alkali, acid, heat at 800°C, grit blasted with Al₂O₃, and grit blasted followed by heat treatment. HA coating was prepared using a two-step procedure. First step was the chemical deposition of a monetite coating on Ti substrate in acidic condition at 75°C and the second step was the hydrolysis of the monetite coating to HA. Coatings were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The roughness of substrates and coatings was measured using profilometry technique. The mechanical stability of the coatings deposited on the pretreated substrates was assessed using scratch test. The coatings deposited on the grit-blasted Ti surface demonstrated superior adhesive properties with critical shearing stress 131.6 ± 0.2 MPa.

  13. Monitoring tablet surface roughness during the film coating process

    DEFF Research Database (Denmark)

    Seitavuopio, Paulus; Heinämäki, Jyrki; Rantanen, Jukka

    2006-01-01

    the process of film coating tablets were studied by noncontact laser profilometry and scanning electron microscopy (SEM). An EDX analysis was used to monitor the magnesium stearate and titanium dioxide of the tablets. The tablet cores were film coated with aqueous hydroxypropyl methylcellulose, and the film...... coating was performed using an instrumented pilot-scale side-vented drum coater. The SEM images of the film-coated tablets showed that within the first 30 minutes, the surface of the tablet cores was completely covered with a thin film. The magnesium signal that was monitored by SEM-EDX disappeared after...... ~15 to 30 minutes, indicating that the tablet surface was homogeneously covered with film coating. The surface roughness started to increase from the beginning of the coating process, and the increase in the roughness broke off after 30 minutes of spraying. The results clearly showed that the surface...

  14. Electrophoretic deposition of a bioactive Si, Ca-rich glass coating on 316L stainless steel for biomedical applications

    Directory of Open Access Journals (Sweden)

    H. H. Rodríguez

    2011-12-01

    Full Text Available This work consisted in the development and characterization of a vitroceramic coating on 316L stainless steel bymeans of electrophoretic deposition (EPD. This vitroceramic coating was obtained through a Si-, Ca-rich glas coating crystallization. The electrophoretic deposition tests were performed on 316L stainless steel mechanically polished substrates. The results suggest that the electrophoretic coatings adhered well to the metallic surfaces. Theresults demonstrate that the crystallized coatings are potentially bioactive, because a dense and homogeneous apatite layer, similar to a bone, makes up.

  15. CHEMICALLY DEPOSITED SILVER FILM USED AS A SERS-ACTIVE OVER COATING LAYER FOR POLYMER FILM

    Institute of Scientific and Technical Information of China (English)

    Xiao-ning Liu; Gi Xue; Yun Lu; Jun Zhang; Fen-ting Li; Chen-chen Xue; Stephen Z.D. Cheng

    2001-01-01

    When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surfaceenhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of liquid crystal film were successfully performed without disturbing the surface morphology.

  16. Optical properties and environmental stability of oxide coatings deposited by reactive sputtering.

    Science.gov (United States)

    Edlou, S M; Smajkiewicz, A; Al-Jumaily, G A

    1993-10-01

    Refractory metal-oxide coatings are deposited by reactive dc magnetron sputtering in an oxygen environment. The optical constants and the environmental stability of silicon oxide, aluminium oxide, hafnium oxide, zirconium oxide, tantalum oxide, titanium oxide, and a blend of hafnium oxide with silicon oxide are investigated. Properties of both single-layer and multilayer interference filters are examined.

  17. Toughening mechanism for Ni-Cr-B-Si-C laser deposited coatings

    NARCIS (Netherlands)

    Hemmati, I.; Ocelik, V.; De Hosson, J. Th. M.

    2013-01-01

    Laser deposited coatings were made from Colmonoy 69 Ni-Cr-B-Si-C alloy and Nb-modified Colmonoy 69 using laser cladding with powder injection. Addition of Nb was done to decrease the structural scale of Cr boride precipitates by providing Nb-rich nucleation agents. The purpose of the study was to ev

  18. Structure of anodized Al–Zr sputter deposited coatings and effect on optical appearance

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Canulescu, Stela; Shabadi, Rajashekhara;

    2014-01-01

    The mechanism of interaction of light with the microstructure of anodized layer giving specific optical appearance is investigated using Al–Zr sputter deposited coating as a model system on an AA6060 substrate. Differences in the oxidative nature of various microstructural components result in th...

  19. Electrolytic deposition of hydroxyapatite coating on thermal treated Ti-40Zr.

    Science.gov (United States)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Lin, Chih-Hung; Ho, Wen-Fu

    2009-09-01

    In this study, hydroxyapatite (HA) was coated on both thermal treated and untreated Ti-40Zr substrates by means of electrolytic deposition. It was predicted that the HA layer would increase the bioactivity and osteoconductivity of the Ti-40Zr substrate, and a thermal treatment would improve the bonding strength between the HA layer and Ti-40Zr substrate, and prevent the corrosion of the Ti-40Zr substrate. First, the Ti-40Zr samples were annealed at various temperatures (200, 300, 400, 500 and 600 degrees C respectively). After annealing, samples were immersed in a Ca(NO(3))(2).4H(2)O and (NH(4))(3)PO(4).3H(2)O solution for the electrolytic deposition of the HA coating. Various analyses of the coating were conducted, including surface morphology, phase structure, corrosion resistance, biocompatibility, and bond strength between HA and Ti-40Zr. Experimental results indicated that the bonding strength of the HA coating on the thermal treated Ti-40Zr was markedly improved when compared to that of the HA coating on an untreated Ti-40Zr alloy. The corrosion resistance of Ti-40Zr was also improved by the use of the thermal treatment, as shown by a potentiodynamic polarization test. Finally, osteoblast-like cells cultured on the HA coating surface were found to have proliferated on all samples.

  20. Sealing of hard CrN and DLC coatings with atomic layer deposition.

    Science.gov (United States)

    Härkönen, Emma; Kolev, Ivan; Díaz, Belén; Swiatowska, Jolanta; Maurice, Vincent; Seyeux, Antoine; Marcus, Philippe; Fenker, Martin; Toth, Lajos; Radnoczi, György; Vehkamäki, Marko; Ritala, Mikko

    2014-02-12

    Atomic layer deposition (ALD) is a thin film deposition technique that is based on alternating and saturating surface reactions of two or more gaseous precursors. The excellent conformality of ALD thin films can be exploited for sealing defects in coatings made by other techniques. Here the corrosion protection properties of hard CrN and diamond-like carbon (DLC) coatings on low alloy steel were improved by ALD sealing with 50 nm thick layers consisting of Al2O3 and Ta2O5 nanolaminates or mixtures. In cross sectional images the ALD layers were found to follow the surface morphology of the CrN coatings uniformly. Furthermore, ALD growth into the pinholes of the CrN coating was verified. In electrochemical measurements the ALD sealing was found to decrease the current density of the CrN coated steel by over 2 orders of magnitude. The neutral salt spray (NSS) durability was also improved: on the best samples the appearance of corrosion spots was delayed from 2 to 168 h. On DLC coatings the adhesion of the ALD sealing layers was weaker, but still clear improvement in NSS durability was achieved indicating sealing of the pinholes.

  1. Pulsed laser deposition of antimicrobial silver coating on Ormocer (registered) microneedles

    Energy Technology Data Exchange (ETDEWEB)

    Gittard, S D; Narayan, R J; Jin, C; Monteiro-Riviere, N A [Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Ovsianikov, A; Chichkov, B N [Laser Zentrum Hannover, Hollerithallee 8, 30419 Hannover (Germany); Stafslien, S; Chisholm, B, E-mail: roger_narayan@msn.co [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States)

    2009-12-15

    One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition. The antibacterial activity of the silver-coated organically modified ceramic (Ormocer (registered) ) microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer (registered) surfaces coated with silver was similar to that on uncoated Ormocer (registered) surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality. (communication)

  2. Simulation and experimental study of CVD process for low temperature nanocrystalline silicon carbide coating

    Energy Technology Data Exchange (ETDEWEB)

    Kaushal, Amit; Prakash, Jyoti, E-mail: jprakash@barc.gov.in; Dasgupta, Kinshuk; Chakravartty, Jayanta K.

    2016-07-15

    Highlights: • Parametric simulation was carried out for specially designed CVD reactor. • Effect of fluid velocity, heat flow and concentration were studied in CVD reactor. • Coating study carried out using low temperature and environmental safe CVD process. • Dense and uniform nanocrystalline SiC film was coated on zircaloy substrate. - Abstract: There is a huge requirement for development of a coating technique in nuclear industry, which is environmentally safe, economical and applicable to large scale components. In this view, simulation of gas-phase behavior in specially designed CVD reactor was carried out using computational tool, COMSOL. There were two important zones in CVD reactor first one is precursor vaporization zone and second one is coating zone. Optimized parameters for coating were derived from the simulation of gas phase dynamics in both zone of CVD reactor. The overall effect of fluid velocity, heat flow and concentration profile showed that Re = 54 is the optimum reaction condition for uniform coating in CVD system. In CVD coating experiments a synthesized halogen free, non-toxic and non-corrosive silicon carbide precursor was used. Uniform coating of SiC was obtained on zircaloy substrate at 900 °C using as synthesized organosilicon precursor. The X-ray diffraction and scanning electron microscopy analysis show that dense nano crystalline SiC film was deposited on zircaloy substrate.

  3. SOME ASPECTS OF TECHNOLOGICAL PROCESS OF CASTINGS IN COATED CHILL

    Directory of Open Access Journals (Sweden)

    A. N. Krutilin

    2010-01-01

    Full Text Available Analysis of technological process of pouring into coated iron chill is presented. It is shown that the process is very sensitive to the change of technological parameters, is rather complex in regulation and control.

  4. Surface Properties of Poly[2-perfluorooctyl)ethyl acrylate] Deposited from Liquid CO2 High-Pressure Fee Meniscus Coating

    Energy Technology Data Exchange (ETDEWEB)

    Kim,J.; Efimenko, K.; Genzer, J.; Carbonell, R.

    2007-01-01

    The surface characteristics of poly[2-(perfluorooctyl)ethyl acrylate] (PFOEA) films deposited using a high-pressure free meniscus coating (hFMC) process with liquid CO{sub 2} (l-CO{sub 2}) as the coating solvent on 12.5 cm diameter silicon wafer substrates were investigated using contact angle measurements, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near-edge X-ray adsorption fine structure (NEXAFS) spectroscopy. The results were compared with surface property measurements of PFOEA films deposited from 1,1,2-trichlorotrifluoroethane (Freon 113) under normal dip coating conditions at atmospheric pressure. NEXAFS measurements showed that perfluoroalkyl groups in the films from l-CO{sub 2} and Freon 113 were well-organized and oriented normal to the substrate at the air/polymer interface. AFM images and XPS measurements revealed that a terrace-like structure of the PFOEA film from l-CO{sub 2} resulted in carbonyl group exposure at the air/polymer interface. This leads to smaller contact angles on the films cast from l-CO{sub 2} relative to the specimens deposited from Freon 113. Annealing the films deposited from the solvents resulted in droplet formation on the surface due to dewetting. The critical surface tension ({gamma}{sub c}) after annealing the film prepared from Freon 113 increased from 6.5 to 8.5 mJ/m{sup 2}, whereas {gamma}{sub c} of the film deposited from l-CO{sub 2} decreased slightly from 9.7 to 8.9 mJ/m{sup 2}. We discuss how surface morphology changes before and after annealing play a role in the variation of {gamma}{sub c}.

  5. Influence of the Discharge Voltage during Pulse-Plasma Process on the Durability of Edges coated with Superhard Coatings

    Institute of Scientific and Technical Information of China (English)

    Maciej Kupczyk

    2004-01-01

    In the paper the experimental results concerning the functional quality of thin, superhard coatings produced on cutting edges is described. Boron nitride coatings were deposited on insert cutting edges made cemented carbides by the pulse-plasma method. The comparative investigations of mentioned coatings have been concerned of tool life of edges during steel machining. In these investigations for the purpose of additional increase of coated edge durability an interfacial layers were applied. Presented investigations particularly pointed out to essential influence of the values of discharge voltage on the coating structure and durability of edges coated with boron nitride.

  6. Influence of the Discharge Voltage during Pulse-Plasma Process on the Durability of Edges coated with Superhard Coatings

    Institute of Scientific and Technical Information of China (English)

    MaciejKupczyk

    2004-01-01

    In the paper the experimental results concerning the functional quality of thin, superhard coatings produced on cutting edges is described. Boron nitride coatings were deposited on insert cutting edges made cemented carbides by the pulse-plasma method. The comparative investigations of mentioned coatings have been concerned of tool life of edges during steel machining. In these investigations for the purpose of additional increase of coated edge durability an interfacial layers were applied. Presented investigations particularly pointed out to essential influence of the values of discharge voltage on the coating structure and durability of edges coated with boron nitfide.

  7. Phase evolution and thermal properties of yttria-stabilized hafnia nano-coatings deposited on alumina

    Science.gov (United States)

    Rubio, Ernesto Javier

    High-temperature coatings are critical to the future power-generation systems and industries. Thermal barrier coatings (TBCs), which are usually the ceramic materials applied as thin coatings, protect engine components and allow further increase in engine temperatures for higher efficiency. Thus, the durability and reliability of the coating systems have to be more robust compared to current natural gas based engines. While a near and mid-term target is to develop TBC architecture with a 1300 °C surface temperature tolerance, a deeper understanding of the structure evolution and thermal behavior of the TBC-bond coat interface, specifically the thermally grown oxide (TGO), is of primary importance. In the present work, attention is directed towards yttria-stabilized hafnia (YSH) coatings on alumina (α-Al2O 3) to simulate the TBC-TGO interface and understand the phase evolution, microstructure and thermal oxidation of the coatings. YSH coatings were grown on α-Al2O3 substrates by sputter deposition by varying coating thickness in a wide range ˜30-1000 nm. The effect of coating thickness on the structure, morphology and the residual stress has been investigated using X-ray diffraction (XRD) and high resolution scanning electron microscopy (SEM). Thermal oxidation behavior of the coatings has been evaluated using the isothermal oxidation measurements under static conditions. X-ray diffraction analyses revealed the existence of monoclinic hafnia phase for relatively thin coatings indicating that the interfacial phenomena are dominant in phase stabilization. The evolution towards pure stabilized cubic phase of hafnia with the increasing coating thickness is observed. The SEM results indicate the changes in morphology of the coatings; the average grain size increases from 15 to 500 nm with increasing thickness. Residual stress was calculated employing XRD using the variable ψ-angle. Relation between residual stress and structural change is also studied. The results

  8. Superhydrophobic coatings for aluminium surfaces synthesized by chemical etching process

    Directory of Open Access Journals (Sweden)

    Priya Varshney

    2016-10-01

    Full Text Available In this paper, the superhydrophobic coatings on aluminium surfaces were prepared by two-step (chemical etching followed by coating and one-step (chemical etching and coating in a single step processes using potassium hydroxide and lauric acid. Besides, surface immersion time in solutions was varied in both processes. Wettability and surface morphologies of treated aluminium surfaces were characterized using contact angle measurement technique and scanning electron microscopy, respectively. Microstructures are formed on the treated aluminium surfaces which lead to increase in contact angle of the surface (>150°. Also on increasing immersion time, contact angle further increases due to increase in size and depth of microstructures. Additionally, these superhydrophobic coatings show excellent self-cleaning and corrosion-resistant behavior. Water jet impact, floatation on water surface, and low temperature condensation tests assert the excellent water-repellent nature of coatings. Further, coatings are to be found mechanically, thermally, and ultraviolet stable. Along with, these coatings are found to be excellent regeneration ability as verified experimentally. Although aforesaid both processes generate durable and regenerable superhydrophobic aluminium surfaces with excellent self-cleaning, corrosion-resistant, and water-repellent characteristics, but one-step process is proved more efficient and less time consuming than two-step process and promises to produce superhydrophobic coatings for industrial applications.

  9. Fast deposition of hydroxyapatite coating on titanium to modify cell affinity of corneal fibroblast in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaoping; MA Xiao; WANG Leyun; DU Xuan; HUANG Yifei; CUI Fuzhai

    2007-01-01

    By two step acid-alkali pretreatment and lmmersing into supersaturated calcification solution,hydroxyapatite (HA)coating was deposited on titanium(Ti)discs.The composition,surface morphology and cross-section of the coating were analyzed by X-ray diffraction(XRD)and scanning electron microscopy (SEM).Fibroblasts of rabbit cornea were seeded on HA coated Ti disc,pure Ti disc and glass.Cell adhesion,proliferation and morphology were detected at 24,48 and 72h,respectively.It is shown for the first time that HA coating can significantly enhance the adhesion and proliferation of rabbit corneal fibroblast in comparison with that of pure Ti.

  10. Microstructure and Corrosion Resistance of Aluminium and Copper Composite Coatings Deposited by LPCS Method

    Directory of Open Access Journals (Sweden)

    Winnicki M.

    2016-12-01

    Full Text Available The paper presents the study of microstructure and corrosion resistance of composite coatings (Al+Al2O3 and Cu+Al2O3 deposited by Low Pressure Cold Spraying method (LPCS. The atmospheric corrosion resistance was examined by subjecting the samples to cyclic salt spray and Kesternich test chambers, with NaCl and SO2 atmospheres, respectively. The selected tests allowed reflecting the actual working conditions of the coatings. The analysis showed very satisfactory results for copper coatings. After eighteen cycles, with a total time of 432 hours, the samples show little signs of corrosion. Due to their greater susceptibility to chloride ions, aluminium coatings have significant corrosion losses.

  11. Particle emission rates during electrostatic spray deposition of TiO2 nanoparticle-based photoactive coating.

    Science.gov (United States)

    Koivisto, Antti J; Jensen, Alexander C Ø; Kling, Kirsten I; Kling, Jens; Budtz, Hans Christian; Koponen, Ismo K; Tuinman, Ilse; Hussein, Tareq; Jensen, Keld A; Nørgaard, Asger; Levin, Marcus

    2018-01-05

    Here, we studied the particle release rate during Electrostatic spray deposition of anatase-(TiO2)-based photoactive coating onto tiles and wallpaper using a commercially available electrostatic spray device. Spraying was performed in a 20.3m(3) test chamber while measuring concentrations of 5.6nm to 31μm-size particles and volatile organic compounds (VOC), as well as particle deposition onto room surfaces and on the spray gun user hand. The particle emission and deposition rates were quantified using aerosol mass balance modelling. The geometric mean particle number emission rate was 1.9×10(10)s(-1) and the mean mass emission rate was 381μgs(-1). The respirable mass emission-rate was 65% lower than observed for the entire measured size-range. The mass emission rates were linearly scalable (±ca. 20%) to the process duration. The particle deposition rates were up to 15h(-1) for coated with carbon, and Ag particles with size ranging from 60nm to ca. 5μm. As expected, no significant VOC emissions were observed as a result of spraying. Finally, we provide recommendations for exposure model parameterization. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  12. The Characteristics of an Antibacterial TiAgN Thin Film Coated by Physical Vapor Deposition Technique.

    Science.gov (United States)

    Kang, Byeong-Mo; Jeong, Woon-Jo; Park, Gye-Choon; Yoon, Dong-Joo; Ahn, Ho-Geun; Lim, Yeong-Seog

    2015-08-01

    In this work, we found the characteristics of an antibacterial TiAgN thin film coated on the pure titanium specimen via the physical vapor deposition process (PVD). TiAgN thin films were coated using TiAg alloy targets by arc ion plating method. Changing the process parameters, the surface analysis of TiAgN thin film was observed by FE-SEM and the force of adhesion was measured with Scratch Tester. The proliferation of human gingival fibroblast (HGF) cells was examined by XTT test assay and the antibacterial properties were investigated by culturing Streptococus Mutans (KCTC 3065) using paper disk techniques. At the result of experiment, cytotoxic effects were not found and the antibacterial effects against Streptococus Mutans were appeared over 5 wt% TiAgN specimens.

  13. Microstructure and mechanical properties of nanocomposite coatings deposited by cathodic arc evaporation

    Directory of Open Access Journals (Sweden)

    K. Lukaszkowicz

    2010-09-01

    Full Text Available Purpose: The main aim of the this research was the investigation of the structure and the mechanical properties of the nanocomposite TiAlSiN, CrAlSiN, AlTiCrN coatings deposited by cathodic arc evaporation method onto hot work tool steel substrate.Design/methodology/approach: The surfaces’ topography and the structure of the PVD coatings were observed on the scanning electron microscopy. Diffraction and thin film structure were tested with the use of the transmission electron microscopy. The microhardness tests were made on the dynamic ultra-microhardness tester. Tests of the coatings’ adhesion to the substrate material were made using the scratch test.Findings: It was found that the structure of the PVD coatings consisted of fine crystallites, while their average size fitted within the range of 11-25 nm, depending on the coating type. The coatings demonstrated columnar structure and dense cross-section morphology as well as good adhesion to the substrate. The critical load LC2 lies within the range of 46-54 N, depending on the coating and substrate type. The coatings demonstrate a high hardness (~40 GPa.Practical implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the coatings. The very good mechanical properties of the nanocomposite coatings make them suitable in industrial applications.Originality/value: The investigation results will provide useful information to applying the nanocomposite coatings for the improvement of mechanical properties of the hot work tool steels.

  14. Influence of carbon nanotubes coatings onto carbon fiber by oxidative treatments combined with electrophoretic deposition on interfacial properties of carbon fiber composite

    Science.gov (United States)

    Deng, Chao; Jiang, Jianjun; Liu, Fa; Fang, Liangchao; Wang, Junbiao; Li, Dejia; Wu, Jianjun

    2015-12-01

    To improve the interfacial performance of carbon fiber (CF) and epoxy resin, carbon nanotubes (CNTs) coatings were utilized to achieve this purpose through coating onto CF by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition (EPD) process. The influence of electrophoretically deposited CNTs coatings on the surface properties of CFs were investigated by Fourier transform infrared spectrometer, atomic force microscopy, scanning electron microscopy and dynamic contact angle analysis. The results indicated that the deposition of carbon nanotubes introduced some polar groups to carbon fiber surfaces, enhanced surface roughness and changed surface morphologies of carbon fibers. Surface wettability of carbon fibers may be significantly improved by increasing surface free energy of the fibers due to the deposition of CNTs. The thickness and density of the coatings increases with the introduction of pretreatment of the CF during the EPD process. Short beam shear test was performed to examine the effect of carbon fiber functionalization on mechanical properties of the carbon fiber/epoxy resin composites. The interfacial adhesion of CNTs/CF reinforced epoxy composites showed obvious enhancement of interlaminar shear strength by 60.2% and scanning electron microscope photographs showed that the failure mode of composites was changed after the carbon fibers were coated with CNTs.

  15. Improving Erosion Resistance of Plasma-Sprayed Ceramic Coatings by Elevating the Deposition Temperature Based on the Critical Bonding Temperature

    Science.gov (United States)

    Yao, Shu-Wei; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

    2017-09-01

    Interlamellar bonding within plasma-sprayed coatings is one of the most important factors dominating the properties and performance of coatings. The interface bonding between lamellae significantly influences the erosion behavior of plasma-sprayed ceramic coatings. In this study, TiO2 and Al2O3 coatings with different microstructures were deposited at different deposition temperatures based on the critical bonding temperature concept. The erosion behavior of ceramic coatings was investigated. It was revealed that the coatings prepared at room temperature exhibit a typical lamellar structure with numerous unbonded interfaces, whereas the coatings deposited at the temperature above the critical bonding temperature present a dense structure with well-bonded interfaces. The erosion rate decreases sharply with the improvement of interlamellar bonding when the deposition temperature increases to the critical bonding temperature. In addition, the erosion mechanisms of ceramic coatings were examined. The unbonded interfaces in the conventional coatings act as pre-cracks accelerating the erosion of coatings. Thus, controlling interlamellar bonding formation based on the critical bonding temperature is an effective approach to improve the erosion resistance of plasma-sprayed ceramic coatings.

  16. Alternating Current Electrophoretic Deposition of Antibacterial Bioactive Glass-Chitosan Composite Coatings

    Directory of Open Access Journals (Sweden)

    Sigrid Seuss

    2014-07-01

    Full Text Available Alternating current (AC electrophoretic deposition (EPD was used to produce multifunctional composite coatings combining bioactive glass (BG particles and chitosan. BG particles of two different sizes were used, i.e., 2 μm and 20–80 nm in average diameter. The parameter optimization and characterization of the coatings was conducted by visual inspection and by adhesion strength tests. The optimized coatings were investigated in terms of their hydroxyapatite (HA forming ability in simulated body fluid (SBF for up to 21 days. Fourier transform infrared (FTIR spectroscopy results showed the successful HA formation on the coatings after 21 days. The first investigations were conducted on planar stainless steel sheets. In addition, scaffolds made from a TiAl4V6 alloy were considered to show the feasibility of coating of three dimensional structures by EPD. Because both BG and chitosan are antibacterial materials, the antibacterial properties of the as-produced coatings were investigated using E. coli bacteria cells. It was shown that the BG particle size has a strong influence on the antibacterial properties of the coatings.

  17. Lubrication analysis of the nanometric coating film deposited during gravure printing

    Science.gov (United States)

    Ceyhan, Umut; Kitsomboonloha, Rungrot; Morris, S. J. S.; Subramanian, Vivek

    2012-11-01

    We report the importance of doctor blade-tip's geometry and wettability on the formation of coating film of thickness 1-10 nm after wiping of the excess ink used for gravure printing of electronics. Several authors have worked on the blade coating problem, addressing elastohydrodynamic effects; however, the coating film deposited during gravure printing is about 3 orders of magnitude thinner than micrometer scale created in blade coating. The blade-tip radius is consequently large compared with the film and gap thickness, allowing the blade tip to be approximated by a parabola. Hydrodynamic forces are concentrated within this inner region. In the gap entry, streamlines converge making the pressure large and positive; downstream, streamlines diverge making pressure large, but negative. This large negative pressure affects the coating film thickness by tending to draw the meniscus back into the narrow gap. Gap thickness and coating film thickness are determined as part of the solution of a free-boundary problem: we couple lubrication analysis of the gap flow in the gap to Landau-Levich analysis of the film flow. The resultant hydrodynamic force and couple exerted within the inner region are compared with those exerted on the outer portion of the blade and parameters affecting the solution of the problem on the coating film formation are examined in detail.

  18. THE STUDY ON MECHANISM OF BINDER MIGRATION DURING COATING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Yun Liang; Kefu Chen

    2004-01-01

    Binder migration during coating process and the mechanism of binder migration were studied in this paper. After the latex was tagged by osmium, the degree of binder migration was measured by energy-dispersive X-ray spectrometer. For the wet sample just after coating application, the real information of binder distribution was kept by quenching the sample in liquid nitrogen followed by freeze-drying. The results showed: under the condition of this research, binder migration occurred both in the process of coating application and drying.But the amount of binder migration occurred during coating application was much little than that occurred during drying. The mechanism of binder migration during the process of coating application was studied by force analyses. And one viewpoint was proposed that was binder migration was caused by Magnus force and Saffman force.

  19. Acoustic monitoring of a fluidized bed coating process

    DEFF Research Database (Denmark)

    Naelapaa, Kaisa; Veski, Peep; Pedersen, Joan G.;

    2007-01-01

      The aim of the study was to investigate the potential of acoustic monitoring of a production scale fluidized bed coating process. The correlation between sensor signals and the estimated amount of film applied and percentage release, respectively, were investigated in coating potassium chloride...

  20. Applications of edible films and coatings to processed foods

    Science.gov (United States)

    Edible coatings have been successfully applied in processed foods such as meat, cereals, confectionaries, dried fruits, nuts and fresh and fresh-cut fruits and vegetables. These coatings are used to improve the quality and shelf-life of foods. Furthermore, different food ingredients, derived from ...

  1. Structure and sliding wear behavior of 321 stainless steel/Al composite coating deposited by high velocity arc spraying technique

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-xiong; XU Bin-shi; LIU Yan; LIANG Xiu-bing; XU Yi

    2008-01-01

    A typical 321 stainless steel/aluminum composite coating (321/Al coating) was prepared by high velocity arc spraying technique (HVAS) with 321 stainless steel wire as the anode and aluminum wire as the cathode.The traditional 321 stainless steel coating was also prepared for comparison.Tribological properties of the coatings were evaluated with the ring-block wear tester under different conditions.The structure and worn surface of the coatings were analyzed by scanning electron microscopy (SEM),X-ray diffractometry (XRD) and energy dispersion spectroscopy (EDS).The results show that,except for aluminum phase addition in tne 321/Al coating,no other phases are created compared with the 321 coating.However,due to the addition of aluminum,the 321/Al coating forms a type of "ductile/hard phases inter-deposited" structure and performs quite different tribological behavior.Under the dry sliding condition,the anti-wear property of 321/Al coating is about 42% lower than that of 321 coating.Butunder the oil lubricated conditions with or without 32h oil-dipping pretreatment,the anti-wear property of 321/Al coating is about 9% and 5% higher than that of 321 coating,respectively.The anti-wear mechanism of the composite coating is mainly relevant to the decrease of oxide impurities and the strengthening action resulted from the "ductile/hard phases inter-deposited" coating structure.

  2. Analysis on Residual Stress in Electron Beam-Physical Vapor Deposited Thermal Barrier Coating using Hard Synchrotron X-Rays

    OpenAIRE

    鈴木, 賢治; 松本, 一秀; 久保, 貴博; 町屋, 修太郎; 田中, 啓介; 秋庭, 義明; SUZUKI, Kenji; MATSUMOTO, Kazuhide; Kubo, Takahiro; Machiya, Syutaro; Tanaka, Keisuke; Akiniwa, Yoshiaki

    2005-01-01

    The distribution of the residual stress in the thermal barrier coating, which was made by an electron beam-physical vapor deposition (EB-PVD) method, was determined using X-ray stress measurements. As the bond coating, NiCoCrAlY was low-pressure plasma sprayed on the substrate of austenitic stainless steel. The 8 mass% Y_2O_3-ZrO_2 was coated on the bond coating using the EB-PVD method as the top coating. The top coating had the preferred orientation with the axis direction perpendicular to ...

  3. Mechanism of the electrochemical deposition of samarium-based coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Edgar J. [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro Sanfandila, P.O. Box 064, Pedro Escobedo, 76700 Queretaro (Mexico); Ortega-Borges, Raul [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro Sanfandila, P.O. Box 064, Pedro Escobedo, 76700 Queretaro (Mexico); Godinez, Luis A. [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro Sanfandila, P.O. Box 064, Pedro Escobedo, 76700 Queretaro (Mexico); Chapman, Thomas W. [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro Sanfandila, P.O. Box 064, Pedro Escobedo, 76700 Queretaro (Mexico); Meas-Vong, Yunny [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro Sanfandila, P.O. Box 064, Pedro Escobedo, 76700 Queretaro (Mexico)]. E-mail: yunnymeas@cideteq.mx

    2006-11-12

    Samarium-based films have been shown to form from aqueous solutions on the surfaces of metallic substrates such as steel or aluminum, and their presence has been reported to decrease substantially the corresponding corrosion rate of the underlying metallic substrate. Based on previous reports on the deposition of oxides or hydroxides of the closely related element cerium, this work demonstrates that samarium films are formed following a similar mechanism, which involves as the fundamental step an increase in interfacial pH resulting from cathodic oxygen-reduction or hydrogen-evolution reactions. With cyclic voltammetry (CV), electrochemical quartz-crystal microbalance (EQCM) measurements, rotating-disk electrode (RDE) tests, and surface characterization techniques, namely, scanning electron microscopy (SEM) and X-ray surface microanalysis (EDX), the postulated mechanism was verified, and the surface morphology of the resulting films was correlated with the nature of the reduction reaction that triggers film formation.

  4. Rapidly-deposited polydopamine coating via high temperature and vigorous stirring: formation, characterization and biofunctional evaluation.

    Directory of Open Access Journals (Sweden)

    Ping Zhou

    Full Text Available Polydopamine (PDA coating provides a promising approach for immobilization of biomolecules onto almost all kinds of solid substrates. However, the deposition kinetics of PDA coating as a function of temperature and reaction method is not well elucidated. Since dopamine self-polymerization usually takes a long time, therefore, rapid-formation of PDA film becomes imperative for surface modification of biomaterials and medical devices. In the present study, a practical method for preparation of rapidly-deposited PDA coating was developed using a uniquely designed device, and the kinetics of dopamine self-polymerization was investigated by QCM sensor system. It was found that high temperature and vigorous stirring could dramatically speed up the formation of PDA film on QCM chip surface. Surface characterization, BSA binding study, cell viability assay and antibacterial test demonstrates that the polydopamine coating after polymerization for 30 min by our approach exhibits similar properties to those of 24 h counterpart. The method has a great potential for rapid-deposition of polydopamine films to modify biomaterial surfaces.

  5. Rapidly-deposited polydopamine coating via high temperature and vigorous stirring: formation, characterization and biofunctional evaluation.

    Science.gov (United States)

    Zhou, Ping; Deng, Yi; Lyu, Beier; Zhang, Ranran; Zhang, Hai; Ma, Hongwei; Lyu, Yalin; Wei, Shicheng

    2014-01-01

    Polydopamine (PDA) coating provides a promising approach for immobilization of biomolecules onto almost all kinds of solid substrates. However, the deposition kinetics of PDA coating as a function of temperature and reaction method is not well elucidated. Since dopamine self-polymerization usually takes a long time, therefore, rapid-formation of PDA film becomes imperative for surface modification of biomaterials and medical devices. In the present study, a practical method for preparation of rapidly-deposited PDA coating was developed using a uniquely designed device, and the kinetics of dopamine self-polymerization was investigated by QCM sensor system. It was found that high temperature and vigorous stirring could dramatically speed up the formation of PDA film on QCM chip surface. Surface characterization, BSA binding study, cell viability assay and antibacterial test demonstrates that the polydopamine coating after polymerization for 30 min by our approach exhibits similar properties to those of 24 h counterpart. The method has a great potential for rapid-deposition of polydopamine films to modify biomaterial surfaces.

  6. Rapidly-Deposited Polydopamine Coating via High Temperature and Vigorous Stirring: Formation, Characterization and Biofunctional Evaluation

    Science.gov (United States)

    Zhou, Ping; Deng, Yi; Lyu, Beier; Zhang, Ranran; Zhang, Hai; Ma, Hongwei; Lyu, Yalin; Wei, Shicheng

    2014-01-01

    Polydopamine (PDA) coating provides a promising approach for immobilization of biomolecules onto almost all kinds of solid substrates. However, the deposition kinetics of PDA coating as a function of temperature and reaction method is not well elucidated. Since dopamine self-polymerization usually takes a long time, therefore, rapid-formation of PDA film becomes imperative for surface modification of biomaterials and medical devices. In the present study, a practical method for preparation of rapidly-deposited PDA coating was developed using a uniquely designed device, and the kinetics of dopamine self-polymerization was investigated by QCM sensor system. It was found that high temperature and vigorous stirring could dramatically speed up the formation of PDA film on QCM chip surface. Surface characterization, BSA binding study, cell viability assay and antibacterial test demonstrates that the polydopamine coating after polymerization for 30 min by our approach exhibits similar properties to those of 24 h counterpart. The method has a great potential for rapid-deposition of polydopamine films to modify biomaterial surfaces. PMID:25415328

  7. Bacterial adherence on fluorinated carbon based coatings deposited on polyethylene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Terriza, A; Del Prado, G; Perez, A Ortiz; Martinez, M J; Puertolas, J A; Manso, D Molina; Gonzalez-Elipe, A R; Yubero, F; Barrena, E Gomez; Esteban, J, E-mail: antonia.terriza@icmse.csic.es

    2010-11-01

    Development of intrinsically antibacterial surfaces is of key importance in the context of prostheses used in orthopaedic surgery. In this work we present a thorough study of several plasma based coatings that may be used with this functionality: diamond like carbon (DLC), fluorine doped DLC (F-DLC) and a high fluorine content carbon-fluor polymer (CF{sub X}). The study correlates the surface chemistry and hydrophobicity of the coating surfaces with their antibacterial performance. The coatings were deposited by RF-plasma assisted deposition at room temperature on ultra high molecular weight polyethylene (UHMWPE) samples. Fluorine content and relative amount of C-C and C-F bond types was monitored by X-ray photoelectron spectroscopy and hydrophobicity by water contact angle measurements. Adherence of Staphylococcus aureus and Staphylococcus epidermidis to non-coated and coated UHMWPE samples was evaluated. Comparisons of the adherence performance were evaluated using a paired t test (two materials) and a Kruskall Wallis test (all the materials). S. aureus was statistically significant (p< 0.001) less adherent to DLC and F-DLC surfaces than S. epidermidis. Both bacteria showed reduction of adherence on DLC/UHMWPE. For S. aureus, reduction of bacterial adherence on F-DLC/UHMWPE was statistically significant respect to all other materials.

  8. Infrared and Fluorescence Spectroscopic Investigations of the Acyl Surface Modification of Hydrogel Beads for the Deposition of a Phospholipid Coating.

    Science.gov (United States)

    Grossutti, Michael; Seenath, Ryan; Lipkowski, Jacek

    2015-10-27

    The scaffolded vesicle has been employed as an alternative means of developing natural model membranes and envisioned as a potential nutraceutical transporter. Furthering the research of the scaffolded vesicle system, a nucleophilic substitution reaction was implemented to form an ester linkage between palmitate and terminal hydroxyl groups of dextran in order to hydrophobically modify the hydrogel scaffold. An average tilt angle of 38° of the hydrophobic palmitate modifying layer on the surface of the hydrogel was determined from dichroic ratios obtained from infrared spectra collected in the attenuated total reflection (ATR) configuration. ATR-IR studies of the DMPC-coated acylated hydrogel demonstrated that the hydrocarbon chains of the DMPC coating was similar to those of the DMPC bilayers and that the underlying palmitate layer had a negligible effect on the average tilt angle (26°) of the DMPC coating. The permeability of this acylated hydrogel was investigated with fluorescence spectroscopy and the terbium/dipicolinic acid assay. The hydrophobic modification on the surface of the hydrogel bead allowed for an efficient deposition of a DMPC layer that served as an impermeable barrier to terbium efflux. About 72% of DMPC-coated acylated hydrogel beads showed ideal barrier properties. The remaining 28% were leaking, but the half-life of terbium efflux of the DMPC-coated acylated hydrogel was increasing, and the total amount of leaked terbium was decreasing with the incubation time. The half-life time and the retention were considered a marked improvement relative to past scaffolded vesicle preparations. The process of acylating hydrogel beads for efficient DMPC deposition has been identified as another viable method for controlling the permeability of the scaffolded vesicle.

  9. Bovine serum albumin adsorption to iron-oxide coated sands can change microsphere deposition mechanisms.

    Science.gov (United States)

    Flynn, Raymond M; Yang, Xinyao; Hofmann, Thilo; von der Kammer, Frank

    2012-03-06

    Particulate colloids often occur together with proteins in sewage-impacted water. Using Bovine Serum Albumin (BSA) as a surrogate for protein in sewage, column experiments investigating the capacity of iron-oxide coated sands to remove latex microspheres from water revealed that microsphere attenuation mechanisms depended on antecedent BSA coverage. Dual pulse experiment (DPE) results suggested that where all BSA was adsorbed, subsequent multiple pore volume microsphere breakthrough curves reflected progressively reduced colloid deposition rates with increasing adsorbed BSA content. Modeling colloid responses suggested adsorption of 1 μg BSA generated the same response as blockage by between 7.1 × 10(8) and 2.3 × 10(9) deposited microspheres. By contrast, microsphere responses in DPEs where BSA coverage of the deposition sites approached/reached saturation revealed the coated sand maintained a finite capacity to attenuate microspheres, even when incapable of further BSA adsorption. Subsequent microsphere breakthrough curves demonstrated the matrix's colloid attenuation capacity progressively increased with continued microsphere deposition. Experimental findings suggested BSA adsorption on the sand surface approaching/reaching saturation generated attractive deposition sites for colloids, which became progressively more attractive with further colloid deposition (filter ripening). Results demonstrate that adsorption of a single type of protein may either enhance or inhibit colloid mobility in saturated porous media.

  10. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    DEFF Research Database (Denmark)

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi......, and it increased the barrier property of the modified low-density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively....

  11. Iron-Based Amorphous Coatings Produced by HVOF Thermal Spray Processing-Coating Structure and Properties

    Energy Technology Data Exchange (ETDEWEB)

    Beardsley, M B

    2008-03-26

    The feasibility to coat large SNF/HLW containers with a structurally amorphous material (SAM) was demonstrated on sub-scale models fabricated from Type 316L stainless steel. The sub-scale model were coated with SAM 1651 material using kerosene high velocity oxygen fuel (HVOF) torch to thicknesses ranging from 1 mm to 2 mm. The process parameters such as standoff distance, oxygen flow, and kerosene flow, were optimized in order to improve the corrosion properties of the coatings. Testing in an electrochemical cell and long-term exposure to a salt spray environment were used to guide the selection of process parameters.

  12. Corrosion and wear behaviours of a reactive-sputter-deposited Ta2O5 nanoceramic coating

    Science.gov (United States)

    Hu, Wei; Xu, Jiang; Lu, Xiaolin; Hu, Dongsheng; Tao, Hongliang; Munroe, Paul; Xie, Zong-Han

    2016-04-01

    In order to improve the wear and corrosion resistance of Ti-6Al-4V, a novel β-Ta2O5 nanoceramic coating was synthesised using reactive sputter deposition enabled by double glow discharge plasma technique. The surface topography, chemical composition, and microstructure of the newly developed coating were characterised by a variety of surface analytical techniques. The coating microstructure was found to exhibit a compact striated pattern extending in a direction perpendicular to coating surface, which is composed of equiaxed β-Ta2O5 grains with an average grain size of ∼20 nm, well adhered to the Ti-6A1-4V substrate. The hardness and the Young's modulus of the as-deposited coating were obtained by nanoindentation, and the adhesion strength between the coating and substrate was determined by a scratch tester. The dry sliding wear behaviours of the coating were investigated at room temperature against Si3N4 ceramic balls at room temperature under applied loads ranging from 2.3 N to 5.3 N using a ball-on-disc tribometer. The specific wear rates of the coating exhibited only a slight increase with applied normal load, and were shown to be two orders of magnitude lower than that for Ti-6Al-4V under the same loading condition. Furthermore, the electrochemical behaviour of the coating immersed in 3.5 wt.% NaCl solution was systematically examined by using a range of complementary electrochemical techniques including potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis as well as potential of zero charge (PZC). The results showed that the corrosion resistance of the β-Ta2O5 nanoceramic coating was better than that of Ti-6Al-4V alloy in 3.5 wt.% NaCl solution. Hence, by possessing higher mechanical properties and good wear and corrosion resistance, the β-Ta2O5 nanoceramic coating is considered to be a promising candidate for protection of engineering components operating under harsh conditions.

  13. Deposition and properties of high-velocity-oxygen-fuel and plasma-sprayed Mo-Mo2C composite coatings

    Science.gov (United States)

    Prchlik, L.; Gutleber, J.; Sampath, S.

    2001-12-01

    Molybdenum thermal-spray coatings, dispersion strengthened by molybdenum oxides and molybdenum carbides, play an important role in industrial tribological applications. Traditionally, they have been prepared by plasma and wire flame spraying. High porosity and lower cohesion strength limit their application in situations where both galling and abrasion wear is involved. In this study, high-velocity-oxygen-fuel (HVOF) deposition of molybdenum and molybdenum carbide coatings was attempted. Deposition was achieved for all powders used. Composition, microstructure, mechanical, and wear properties of the HVOF synthesized coatings were evaluated and compared with plasma-sprayed counterparts. The HVOF coatings possessed a very good abrasion resistance, whereas plasma deposits performed better in dry sliding tests. Measurements showed a close relationship between the coating surface hardness and its abrasion resistance. Results also suggested correlation between molybdenum carbide distribution in the molybdenum matrix and the sliding friction response of Mo-Mo2C coatings.

  14. High-frequency electropulse deposition of microcrystallized MGH754 ODS alloy coatings

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A simple but more efficient technique--high-frequency electropulse deposition--was developed to produce microcrystallized MGH754 ODS alloy coatings on the 1Cr18Ni9Ti stainless steel substrate. The coating has a very fine grain size of 30-300 nm and metallurgical bonding with the substrate. Isothermal oxidation in air at 1 000℃ for 100 h shows that micro-crystallisation and dispersed oxide particles promote the selective oxidation of Cr greatly to form a protective and continuous Cr2O3 scale and also improve the scale spallation resistance dramatically, thus increasing the oxidation resistance of 1Cr18Ni9Ti.

  15. Ion-Bombardment of X-Ray Multilayer Coatings - Comparison of Ion Etching and Ion Assisted Deposition

    NARCIS (Netherlands)

    Puik, E. J.; van der Wiel, M. J.; Zeijlemaker, H.; Verhoeven, J.

    1991-01-01

    The effects of two forms of ion bombardment treatment on the reflectivity of multilayer X-ray coatings were compared: ion etching of the metal layers, taking place after deposition, and ion bombardment during deposition, the so-called ion assisted deposition. The ion beam was an Ar+ beam of 200 eV,