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Sample records for coated type 304l

  1. Formation of abrasion-resistant coatings of the AlSiFexMny intermetallic compound type on the AISI 304L alloy

    Directory of Open Access Journals (Sweden)

    Martínez-Perales, Laura G.

    2016-03-01

    Full Text Available The α-Al9FeMnSi and β-Al9FeMn2Si intermetallics formed by reactive sintering of Al, Si, Mn, Fe, Cr and Ni powders have been used in AISI 304L steels to enhance microhardness. Processing variables of the reactive sintering treatment were temperature (600, 650, 700, 750 and 800 °C, pressure (5, 10 y 20 MPa and holding time (3600, 5400 y 7200 seconds. Experimental results show that temperature is the most important variable affecting the substrate/coating formation, while pressure does not appear to have a significant effect. The results show the optimum conditions of the reactive sintering that favor the substrate/coating formation are 800 °C, 20 MPa and 7200 seconds. Under these conditions, the reaction zone between the substrate and coating is more compacted and well-adhered, with a microhardness of 1300 Vickers. The results of SEM and X-Ray diffraction confirmed the formation of α-Al9FeMnSi and β-Al9FeMn2Si intermetallics in the substrate/coating interface as well as the presence of Cr and Ni, indicating diffusion of these two elements from the substrate to the interface.Los intermetálicos α-Al9FeMnSi y β-Al9FeMn2Si formados por sinterización reactiva de polvos Al, Si, Mn, Fe, Cr, Ni se han utilizado en aceros AISI 304L para mejorar la microdureza. Las variables de procesamiento de sinterización reactiva fueron temperatura (600, 650, 700, 750, y 800 °C, presión (5, 10 y 20 MPa y el tiempo de retención (3600, 5400 7200 segundos. Los resultados experimentales muestran que la temperatura es la variable más importante que afecta a la formación del sustrato/recubrimiento, mientras que la presión no parece tener un efecto significativo una influencia significativa. Los resultados muestran las condiciones óptimas de la sinterización reactiva que favorecen la formación del sustrato/recubrimiento a 800 °C, 20 MPa y 7200 segundos. En estas condiciones, la zona de reacción entre el sustrato y el recubrimiento es más compacta y bien

  2. Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

    Science.gov (United States)

    Maheswari, A. Uma; Sivakumar, M.; Indhumathi, N.; Mohan, Sreedevi R.

    2016-09-01

    Influence of substrate temperature on corrosion (in 3.5% NaCl) and wear resistance of nanostructured zirconia thin film coated 304L SS substrates are studied by electrochemical and nano-indentation methods. This analysis shows 304L SS substrate spray coated with nanostructured zirconia at substrate temperature closer to the boiling point of the spray solvent ethanol exhibited good corrosion and wear resistance behaviour. This is because of the compressive stress developed during film fabrication at lower substrate temperature (∼50 °C) and hence constrains the indentation plasticity, which leads to higher indentation load than the bare 304L SS.

  3. Corrosion testing of Type 304L stainless steel for waste tank applications

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.J.; Mickalonis, J.I.

    1991-12-31

    AISI Type 304L stainless steel will be the material of construction for hazardous waste storage tanks. The corrosion behavior of 304L was characterized in simulated waste solutions using potentiodynamic polarization, electrochemical impedance spectroscopy and long term immersion tests. The results were correlated to assess the use of corrosion characteristics determined by electrochemical techniques for predicting long term corrosion behavior. The corrosion behaviors of Type A537 carbon steel and Incoloy 825 were also evaluated. A good correlation was found between the results from the electrochemical techniques and the immersion tests.

  4. Corrosion behaviour of AISI type 304L stainless steel in nitric acid media containing oxidizing species

    Energy Technology Data Exchange (ETDEWEB)

    Ningshen, S. [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kamachi Mudali, U., E-mail: kamachi@igcar.gov.i [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Ramya, S.; Raj, Baldev [Corrosion Science and Technology Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2011-01-15

    Research highlights: Corrosion behaviour of 304L stainless steel has been evaluated in the presence of oxidizing species in nitric acid medium. No significant change in corrosion potential even with increase in temperature and nitric acid concentration in presence of oxidizing ions. Faster passive film dissolution as indicated by low film polarization resistance, with increase in nitric acid concentration and temperature. The presence of oxidizing species further aggravates the corrosion of 304L SS along with increased temperature and nitric acid concentration. - Abstract: The corrosion behaviour of AISI type 304L stainless steel (SS) in different concentration of 0.01 M, 1 M and 5 M HNO{sub 3} in presence of oxidizing ions at different temperatures has been evaluated. The main objective of this study is to assess the corrosion resistance of type 304L SS in non-radioactive conditions encountered during storage of liquid nuclear waste. Electrochemical impedance spectroscopy (EIS) and laser Raman spectroscopy (LRS) has clearly brought out the deleterious effect of oxidizing species on the passive film leading to increased corrosion along with increase in HNO{sub 3} concentration and higher temperature.

  5. Hydrogen effects on flow localization and fracture in type 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R.

    1979-01-01

    The onset of plastic instability, localization of plastic flow, and fracture in Type 304L austenitic stainless steel are modified by the presence of hydrogen. It is not certain, however, whether the observed changes in behavior are attributable to the direct effect of hydrogen on plastic flow or to the intervention of a hydrogen-induced brittle fracture process. The effects are observed in both smooth bar and single edge notched specimens and are dependent on deformation temperature.

  6. Vapor deposition of copper on stainless steel 304L

    Energy Technology Data Exchange (ETDEWEB)

    Vasofsky, R.W.

    1993-08-17

    Y-12 Plant is seeking to minimize the generation of hazardous wastes in its operations. The standard procedure for electroplating a thin layer of copper on type 304L stainless steel requires several aqueous pretreatment steps which generate Resource Conservation and Recovery Act (RCRA) hazardous wastes. We have evaluated a more environmentally acceptable procedure. Copper was vacuum deposited onto 304L coupons under differing deposition conditions and properties of coatings produced, including microstructure and adhesive strength, were examined. Results indicated that a noncolumnar, fine grain copper coating with high adhesion can be produced using this environmentally more acceptable approach.

  7. The effects of surface pretreatment and nitrogen tetroxide purification on the corrosion rate of Type 304L stainless steel

    Science.gov (United States)

    Blue, G. D.; Moran, C. M.

    1985-01-01

    Corrosion rates of 304L stainless steel coupons in MON-1 oxidizer have been measured as a function of cleaning procedures employed, surface layer positions, propellant impurity levels, and short-term exposure durations (14 to 90 days). Of special interest was propellant contamination by buildup of soluble iron, which may cause flow decay. Surface treatments employed were combinations of cleaning, pickling, and passivation procedures. Propellants used were MIL-SPEC MON-1 and several types of purified NTO (i.e., low water, low chloride) which may, at a later time, be specified as spacecraft grade. Pretest coupon surface analysis by X-ray photoelectron spectroscopy (XPS-ESCA) has revealed important differences, for the different cleaning procedures, in the make-up of the surface layer, both in composition and state of chemical combination of the elements involved. Comparisons will be made of XPS/ESCA data, for different cleaning procedures, for specimens before and after propellant exposure.

  8. Effect of welding process, type of electrode and electrode core diameter on the tensile property of 304L austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    Akinlabi OYETUNJI

    2014-11-01

    Full Text Available The effect of welding process, type of electrode and electrode core diameter on the tensile property of AISI 304L Austenitic Stainless Steel (ASS was studied. The tensile strength property of ASS welded samples was evaluated. Prepared samples of the ASS were welded under these three various variables. Tensile test was then carried out on the welded samples. It was found that the reduction in ultimate tensile strength (UTS of the butt joint samples increases with increase in core diameter of the electrode. Also, the best electrode for welding 304L ASS is 308L stainless steel-core electrode of 3.2 mm core diameter. It is recommended that the findings of this work can be applied in the chemical, food and oil industries where 304L ASS are predominantly used.

  9. The propagation of short fatigue crack effect in 304L stainless steel: closure and plasticity effect; Propagation par fatigue des fissures physiquement courtes dans un acier inoxydable de type 304L: role de la fermeture et de la plasticite

    Energy Technology Data Exchange (ETDEWEB)

    Lesur, N

    2005-12-15

    The behaviour of 2D physically short cracks has been studied for an austenitic stainless steel type A304L. Experimental fatigue tests have shown an increase of the threshold fatigue range when the crack length is increasing from 0.1 to 0.8 mm. This effect is explained in term of crack closure variation. The numerical simulation by mean of finite elements supports such an effect of crack closure when computing is performed in plane stress at R=0.1 and R=0.7. Such behaviour is typical for a material characterized by an isotropic and cinematic constitutive cyclic hardening law. The local plasticity effect is shown to control the crack growth rate and has been related to an effective plastic intensity factor range. (author)

  10. Standard test method for electrochemical reactivation (EPR) for detecting sensitization of AISI type 304 and 304L stainless steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This test method covers a laboratory procedure for conducting an electrochemical reactivation (EPR) test on AISI Type 304 and 304L (UNS No. S30400 and S30403, respectively) stainless steels. This test method can provide a nondestructive means of quantifying the degree of sensitization in these steels (1, 2, 3). This test method has found wide acceptance in studies of the effects of sensitization on intergranular corrosion and intergranular stress corrosion cracking behavior (see Terminology G15). The EPR technique has been successfully used to evaluate other stainless steels and nickel base alloys (4), but the test conditions and evaluation criteria used were modified in each case from those cited in this test method. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this...

  11. Solidification Behavior and Weldability of Dissimilar Welds Between a Cr-Free, Ni-Cu Welding Consumable and Type 304L Austenitic Stainless Steel

    Science.gov (United States)

    Sowards, Jeffrey W.; Liang, Dong; Alexandrov, Boian T.; Frankel, Gerald S.; Lippold, John C.

    2012-04-01

    The solidification behavior of a Cr-free welding consumable based on the Ni-Cu system was evaluated in conjunction with Type 304L stainless steel. The weld metal microstructure evolution was evaluated with optical and secondary electron microscopy, energy dispersive spectroscopy, X-ray diffraction, button melting, and thermodynamic (CALPHAD-based) modeling. Solidification partitioning patterns showed that higher dilutions of the filler metal by Type 304L increased segregation of Ti, Cu, and Si to interdendritic regions. Button melting experiments showed a widening of the solidification temperature range with increasing dilution because of the expansion of the austenite solidification range and formation of Ti(C,N) via a eutectic reaction. The model predictions showed good correlation with button melting experiments and were used to evaluate the nature of the Ti(C,N) precipitation reaction. Solidification cracking susceptibility of the weld metal was shown to increase with dilution of 304L stainless steel based on testing conducted with the cast pin tear test. The increase in cracking susceptibility is associated with expansion of the solidification temperature range and the presence of eutectic liquid at the end of solidification that wets solidification grain boundaries.

  12. AES depth profiles in Mo-coated 304L stainless steel achieved by RF-magnetron sputtering and influence of Mo on the corrosion in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Saoula, N. [Division des Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées CDTA, Cité du 20 août 1956, Baba Hassan, BP n 17, Alger (Algeria); Siad, M. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France); Biberian, J.P. [CINaM, UMR 7525 CNRS, Aix Marseille Université, 13288 Marseille Cedex 9 (France)

    2015-10-05

    Highlights: • Mo coating of 304L stainless steel is achieved via RF-magnetron sputtering. • The AES depth profiles before and after annealing in air (at 973 K) are analyzed. • The corrosions in NaCl solution of bare and Mo-coated samples are compared. • Mo-coated steels exhibit better corrosion behaviors. • The positive action of Mo oxide via its semi-conducting properties is deduced. - Abstract: Molybdenum-coated 304L stainless steel samples, fabricated by RF-magnetron sputtering, are characterized by Auger Electron Spectroscopy (AES) before and after annealing in air at 973 K. The electrochemical parameters of bare and coated materials, in NaCl 3.5% water solution at 298 K, are derived from the potentiodynamic polarization curves. The corrosion current of Mo-coated samples (before and after annealing) is significantly lower than that of its bare counterpart. The information gained from the AES depth profiles leads us to infer that the positive action of molybdenum on the corrosion behavior may be attributed to the changes induced by the semi-conducting properties of Mo oxide in the passive film.

  13. Superficial and electrochemical study of stainless steel 304l with an inhibitory protective coating (TiO{sub 2} and ZrO{sub 2}); Estudio superficial y electroquimico de acero inoxidable 304L con una capa protectora inhibidora (TiO{sub 2} y ZrO{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Davila N, M. L.; Contreras R, A.; Arganis J, C. R., E-mail: aida.contreras@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The degradation mechanisms in the boiling water reactors (BWR) have been an alert focus for owners, especially the cracking by stress corrosion cracking (SCC), therefore different techniques have been studied to inhibit this problem inside which is the water injection of hydrogen feeding (HWC, Hydrogen Water Chemistry), together with the noble metals injection (NMCA, Nobel Metal Chemical Addition) and the ceramic materials injection that form an inhibitory protective coating (Ipc). In this work the Ipc was simulated, for which were carried out hydro-thermals deposits starting from suspensions of 1000 ppm of zirconium oxide in its crystalline phase baddeleyite and titanium oxides in its anatase and rutile phases, on test tubes of stainless steel 304l previously rusty under simulated conditions of pressure and temperature of a BWR (288 C and 8 MPa). The superficial characterization was realized by scanning electron microscopy, energy-dispersive of X-ray and X-ray diffraction. The capacity to mitigate the corrosion was studied with the electrochemical technique of Tafel polarization (288 C and 8 MPa). The steel presents the formation of two oxide coatings formed by magnetite and hematite. The baddeleyite presents a deposit more thick and homogeneous it also presents the most negative electrochemical potential of corrosion, what indicates that it has the bigger capacity to mitigate the SCC. (Author)

  14. Optimum design of a hot extrusion process for AISI type 304L stainless steel using a model for the evolution of microstructure

    Science.gov (United States)

    Venugopal, S.; Mannan, S. L.; Rodriguez, P.

    2002-05-01

    The deformation behaviour of 304L stainless steel was evaluated, under compression in the temperature range of 600-1200 °C and strain-rate range of 0.001-100 s-1 from the viewpoint of establishing processing-microstructure relationships during hot working. Ferrite forms at temperatures above 1150 °C during deformation. The material exhibits a dynamic recrystallization (DRX) domain in the temperature range of 1000-1200 °C and strain-rate range of 0.01-5 s-1, which is the optimum one for hot working. The development of microstructure in 304L stainless steel during industrial hot-forming operations such as press forging, rolling, extrusion, and hammer forging at different temperatures in the range 600-1200 °C, was studied and compared with the results of the laboratory tests for assessing the applicability of simulative tests in the optimization of processing parameters. In order to control the final microstructure of the product, an analytical model for the evolution of microstructure during hot working (in the DRX domain) was obtained. Using the above model, the optimum strain, strain-rate, and temperature trajectories were arrived at for obtaining a grain size of 35 µm in an extruded product. Process control parameters, such as ram velocity, die profile, and billet temperature, which achieve the optimal trajectories were calculated using a process model. Extrusion trials were conducted at optimal conditions and a good agreement with those results predicted in the design stage has been achieved.

  15. Initiation and growth of thermal fatigue crack networks in an AISI 304 L type austenitic stainless steel (X2 CrNi18-09); Amorcage et propagation de reseaux de fissures de fatigue thermique dans un acier inoxydable austenitique de type X2 CrNi18-09 (AISI 304 L)

    Energy Technology Data Exchange (ETDEWEB)

    Maillot, V

    2004-07-01

    We studied the behaviour of a 304 L type austenitic stainless steel submitted to thermal fatigue. Using the SPLASH equipment of CEA/SRMA we tested parallelepipedal specimens on two sides: the specimens are continuously heated by Joule effect, while two opposites faces are cyclically. cooled by a mixed spray of distilled water and compressed air. This device allows the reproduction and the study of crack networks similar to those observed in nuclear power plants, on the inner side of circuits fatigued by mixed pressurized water flows at different temperatures. The crack initiation and the network constitution at the surface were observed under different thermal conditions (Tmax = 320 deg C, {delta}T between 125 and 200 deg C). The experiment produced a stress gradient in the specimen, and due to this gradient, the in-depth growth of the cracks finally stopped. The obtained crack networks were studied quantitatively by image analysis, and different parameters were studied: at the surface during the cycling, and post mortem by step-by-step layer removal by grinding. The maximal depth obtained experimentally, 2.5 mm, is relatively coherent with the finite element modelling of the SPLASH test, in which compressive stresses appear at a depth of 2 mm. Some of the crack networks obtained by thermal fatigue were also tested in isothermal fatigue crack growth under 4-point bending, at imposed load. The mechanisms of the crack selection, and the appearance of the dominating crack are described. Compared to the propagation of a single crack, the crack networks delay the propagation, depending on the severity of the crack competition for domination. The dominating crack can be at the network periphery, in that case it is not as shielded by its neighbours as a crack located in the center of the network. It can also be a straight crack surrounded by more sinuous neighbours. Indeed, on sinuous cracks, the loading is not the same all along the crack path, leading to some

  16. Laser Rewelding of 304L Stainless Steel.

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Michael Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rodelas, Jeffrey [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2016-11-01

    Laser welding of 304L stainless steel during component fabrication has been found to alter the chemical composition of the steel due to material evaporation. During repair or rework, or during potential reuse/ rewelding of certain components, the potential exists to alter the composition to the extent that the material becomes prone to solidification cracking. This work aims to characterize the extent of this susceptibility in order to make informed decisions regarding rewelding practice and base metal chemistry allowances.

  17. Quasi-Isentropic Compression of Wrought and Additively Manufactures 304L Stainless Steel

    Science.gov (United States)

    Specht, Paul; Brown, Justin; Wise, Jack; Furnish, Michael; Adams, David

    2017-06-01

    The thermodynamic and constitutive responses of both additively manufactured (AM) and traditional wrought processed 304L stainless steel (SS) were investigated through quasi-isentropic compression to peak stresses near 1Mbar using Sandia National Laboratories' Z machine. The AM 304L SS samples were made with a laser engineered net shaping (LENS™) technique. Compared to traditional wrought processed 304L SS, the AM samples were highly textured with larger grain sizes (i.e.near 1mm) and residual stresses (> 100 MPa). Interferometric measurements of interface velocities enabled inference of the quasi-isentropes for each fabrication type of 304L SS. Release from peak stress provided flow strength measurements of the wrought and AM 304L SS. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Approved For Unclassified Unlimited Release SAND2017-2040A.

  18. Characterization of the deformation and annealing of 304L stainless steel. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, W.H.

    1994-08-01

    Stainless steel, type 304L, was deformed at room temperature using the two processes of semi-piercing and cold-rolling and then annealed at various temperatures and times. The three metallurgical areas of work hardening, age hardening, and anneal softening were observed and characterized using metallography techniques of macrohardness, optical and transmission electron microscopy, and X-ray diffraction.

  19. Mitigation of Stress Corrosion Cracking Susceptibility of Machined 304L Stainless Steel Through Laser Peening

    Science.gov (United States)

    Sundar, R.; Ganesh, P.; Kumar, B. Sunil; Gupta, R. K.; Nagpure, D. C.; Kaul, R.; Ranganathan, K.; Bindra, K. S.; Kain, V.; Oak, S. M.; Singh, Bijendra

    2016-09-01

    The paper describes an experimental study aimed at suppressing stress corrosion cracking susceptibility of machined 304L stainless steel specimens through laser shock peening. The study also evaluates a new approach of oblique laser shock peening to suppress stress corrosion cracking susceptibility of internal surface of type 304L stainless steel tube. The results of the study, performed with an indigenously developed 2.5 J/7 ns Nd:YAG laser, demonstrated that laser shock peening effectively suppresses chloride stress corrosion cracking susceptibility of machined surface of type 304L stainless steel. In the investigated range of incident laser power density (3.2-6.4 GW/cm2), machined specimens peened with power density of 4.5 and 6.4 GW/cm2 displayed lower stress corrosion cracking susceptibility considerably than those treated with 3.2 and 3.6 GW/cm2 in boiling magnesium chloride test. Oblique laser shock peening, performed on machined internal surface of a type 304L stainless steel tube (OD = 111 mm; ID = 101 mm), was successful in introducing residual compressive surface stresses which brought about significant suppression of its stress corrosion cracking susceptibility. The technique of oblique laser shock peening, in spite of its inherent limitations on the length of peened region being limited by tube internal diameter and the need for access from both the sides, presents a simplified approach for peening internal surface of small tubular components.

  20. Inhibition effect of 4-phenylthiazole derivatives on corrosion of 304L stainless steel in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.S. [Department of Chemistry, Faculty of Science, El-Mansoura University, El-Mansoura, 35516 (Egypt)], E-mail: asfouda@hotmail.com; Ellithy, A.S. [AboZaabal Company for Fertilizers and Chemicals (AZFC), Cairo (Egypt)

    2009-04-15

    Some 4-phenylthiazole derivatives were tested as corrosion inhibitors for 304L stainless steel in 3.0 M HCl using weight loss and galvanostatic techniques. The results showed that the inhibition efficiency increases with increasing the concentration of the 4-phenylthiazole derivatives. Polarization measurements showed that these derivatives act as mixed-type inhibitors. The adsorption of these inhibitors on the surface of stainless steel follows Temkin's adsorption isotherm and kinetic model. The effect of temperature on the corrosion was investigated by the weight loss method and some thermodynamic parameters were calculated. The synergistic influence caused by thiocyanate ion on the inhibition of corrosion of 304L stainless steel in 3.0 M HCl in the presence of 4-phenylthiazole derivatives has been studied using weight loss method. The inhibition action of these 4-phenylthiazole derivatives was discussed in terms of its adsorption on the metal surface.

  1. Experimental investigation of friction and wear behaviour of 304L ...

    African Journals Online (AJOL)

    Experimental investigation of friction and wear behaviour of 304L stainless steel sliding against different counterface in dry contact. ... Ife Journal of Science ... All the pairs exhibited initial rapid increase in coefficient of friction after which a variety of friction behavior, depending on the ball counterface, was observed. The flat ...

  2. An Experimental Analysis to Reduce Cracks in Arc Welding in MS and SS 304 (L)

    OpenAIRE

    Vivekanand Jha; Mohd. Abbas

    2014-01-01

    cracks are very common welding defects .Cracks can be hot or cold cracks .Cracks can be reduced by various parameters keeping in mind. The various parameters are 1. Preheat 2.Interpass heating 3.Post weld heat treatment (PWHT) 4. Welding speed 5. Energy input 6. Thickness of joint 7. Stresses 8. High current 9. High carbon content. The aim of this experiment was to study different types of cracks formed during welding process and to reduce the cracking of SS 304 (L) and M.S in...

  3. Abnormal grain growth in AISI 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Shirdel, M., E-mail: mshirdel1989@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Mirzadeh, H., E-mail: hmirzadeh@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Parsa, M.H., E-mail: mhparsa@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Advanced Metalforming and Thermomechanical Processing Laboratory, School of Metallurgy and Materials Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2014-11-15

    The microstructural evolution during abnormal grain growth (secondary recrystallization) in 304L stainless steel was studied in a wide range of annealing temperatures and times. At relatively low temperatures, the grain growth mode was identified as normal. However, at homologous temperatures between 0.65 (850 °C) and 0.7 (900 °C), the observed transition in grain growth mode from normal to abnormal, which was also evident from the bimodality in grain size distribution histograms, was detected to be caused by the dissolution/coarsening of carbides. The microstructural features such as dispersed carbides were characterized by optical metallography, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and microhardness. Continued annealing to a long time led to the completion of secondary recrystallization and the subsequent reappearance of normal growth mode. Another instance of abnormal grain growth was observed at homologous temperatures higher than 0.8, which may be attributed to the grain boundary faceting/defaceting phenomenon. It was also found that when the size of abnormal grains reached a critical value, their size will not change too much and the grain growth behavior becomes practically stagnant. - Highlights: • Abnormal grain growth (secondary recrystallization) in AISI 304L stainless steel • Exaggerated grain growth due to dissolution/coarsening of carbides • The enrichment of carbide particles by titanium • Abnormal grain growth due to grain boundary faceting at very high temperatures • The stagnancy of abnormal grain growth by annealing beyond a critical time.

  4. Temperature distribution of multipass TIG welded AISI 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Esme, Ugur; Guven, Onur [Mersin Univ., Tarsus (Turkey); Bayramoglu, Melih; Serin, Hasan [Cukurova Univ., Adana (Turkey); Aydin, Hakan [Uludag Unaiv., Bursa (Turkey); Kazancoglu, Yigit [Izmir Univ. of Economics (Turkey). Dept. of Business Administration

    2011-07-01

    Tungsten inert gas welding (TIG) is one of the most important material-joining processes widely used in industry. AISI type 304L stainless steel plates with 8 and 10 mm thicknesses are widely used in the fabrication of pressure vessels and other components. These plates are mostly joined together by multipass welding methods. The temperature distribution that occurs during multipass welding affects the material microstructure, hardness, mechanical properties, and the residual stresses that will be present in the welded material. Very limited experimental data regarding temperature distribution during multipass welding of plates is available in the literature. Experimental work was carried out to find out the temperature distribution during multipass welding of the AISI 304L stainless steel plates. The temperature distribution curves obtained during the experiments are presented. The average maximum temperature rise during each pass of welding is calculated and plotted against the distance from the weld pad centre line. From these plots, the maximum temperature rise expected in the base plate region during any pass of welding operation can be estimated. (orig.)

  5. STUDY AND ANALYSIS OF THE EFFECT OF WELDING PROCESS ON DISTORTION WITH 304L STAINLESS STEEL WELD JOINTS

    OpenAIRE

    Dhananjay Kumar*, Dharamvir mangal

    2017-01-01

    The effect of welding process on the distortion with 304L stainless steel 12thk weld joints made by TIG (tungsten inert gas) and SMAW (Shielded metal arc welding) welding process involving different type joint configuration have been studied. The joint configurations employed were double V-groove edge preparation for double side SMAW welding and square – butt preparation for double side TIG welding. All weld joints passed by radiographic. Distortion measurements were carried out using height ...

  6. Impedance investigation of thermally formed oxide films on AISI 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Hamadou, L. [Laboratoire de Materiaux, Electrochimie et Corrosion, Universite Mouloud Mammeri de Tizi-Ouzou, B.P. 17, Tizi-Ouzou 15000 (Algeria)], E-mail: lamhama@yahoo.fr; Kadri, A.; Benbrahim, N. [Laboratoire de Materiaux, Electrochimie et Corrosion, Universite Mouloud Mammeri de Tizi-Ouzou, B.P. 17, Tizi-Ouzou 15000 (Algeria)

    2010-03-15

    Thin oxide layers on 304L stainless steel were grown by thermal oxidation at 300 deg. C at different durations ranging from 2 to 4 h. The structural characterization of the oxide films was carried out by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy was used to investigate the effects of exposure time and applied potential on the electronic properties of these films. Oxide films are described by a multilayer structure, with n-type iron oxide and oxyhydroxide in the outer layers and p-type chromium oxide in the inner layer. Doping densities evaluated from Mott-Schottky plots increased with the oxidation duration, with characteristics of highly disordered semiconductor.

  7. DIC-aided biaxial fatigue tests of a 304L steel

    Science.gov (United States)

    Poncelet, M.; Barbier, G.; Raka, B.; Courtin, S.; Desmorat, R.; Le-Roux, J. C.; Vincent, L.

    2010-06-01

    Several biaxial fatigue tests are conducted up to 106 cycles at room temperature in the context of a collaboration LMT-Cachan / EDF / AREVA / SNECMA / CEA. Malteses cross specimens of 304L steel, designed to initiate crack in the bulk, are loaded by a triaxial testing machine. A Digital Image Correlation technique is used to measure strain during loading and detect crack initiation early. A special optical assembly and a stroboscopic sampling method are set up in this purpose. Several types of loadings are performed: equibiaxial with a loading ratio R = 0.1, equibiaxial with loading ratio R = -1, pseudo uniaxial (cyclic loading at R= 0.1 in one direction and constant loading in the other). First results are commented.

  8. DIC-aided biaxial fatigue tests of a 304L steel

    Directory of Open Access Journals (Sweden)

    Le-Roux J.C.

    2010-06-01

    Full Text Available Several biaxial fatigue tests are conducted up to 106 cycles at room temperature in the context of a collaboration LMT-Cachan / EDF / AREVA / SNECMA / CEA. Malteses cross specimens of 304L steel, designed to initiate crack in the bulk, are loaded by a triaxial testing machine. A Digital Image Correlation technique is used to measure strain during loading and detect crack initiation early. A special optical assembly and a stroboscopic sampling method are set up in this purpose. Several types of loadings are performed: equibiaxial with a loading ratio R = 0.1, equibiaxial with loading ratio R = –1, pseudo uniaxial (cyclic loading at R= 0.1 in one direction and constant loading in the other. First results are commented.

  9. Simulation of Friction Stir Processing in 304L Stainless Steel

    Directory of Open Access Journals (Sweden)

    Miles M.P.

    2016-01-01

    Full Text Available A major dilemma facing the nuclear industry is repair or replacement of stainless steel reactor components that have been exposed to neutron irradiation. When conventional fusion welding is used for weld repair, the high temperatures and thermal stresses inherent in the process enhance the growth of helium bubbles, causing intergranular cracking in the heat-affected zone (HAZ. Friction stir processing (FSP has potential as a weld repair technique for irradiated stainless steel, because it operates at much lower temperatures than fusion welding, and is therefore less likely to cause cracking in the HAZ. Numerical simulation of the FSP process in 304L stainless steel was performed using an Eulerian finite element approach. Model input required flow stresses for the large range of strain rates and temperatures inherent in the FSP process. Temperature predictions in three locations adjacent to the stir zone were accurate to within 4% of experimentally measure values. Prediction of recrystallized grain size at a location about 6mm behind the tool center was less accurate, because the empirical model employed for the prediction did not account for grain growth that occurred after deformation in the experiment was halted.

  10. Microbiological influenced corrosion resistance characteristics of a 304L-Cu stainless steel against Escherichia coli.

    Science.gov (United States)

    Nan, Li; Xu, Dake; Gu, Tingyue; Song, Xiu; Yang, Ke

    2015-03-01

    Cu-bearing antibacterial stainless steels have been gaining popularity in recent years due to their strong antibacterial performances. However, only a few studies were reported for their actual performances against microbiologically influenced corrosion (MIC). In this study, electrochemical methods and surface analytical techniques were applied to study the MIC resistance characteristics of a 304L-Cu stainless steel (SS) against Escherichia coli in comparison with 304L SS as control. Corrosion tests for specimens after a 21-day exposure to a Luria-Bertani (LB) culture medium with E. coli demonstrated that the 304L-Cu SS considerably reduced the maximum MIC pit depth and the specific weight loss compared with 304L SS (8.3μm and 0.2mg/cm(2) vs. 13.4μm and 0.6mg/cm(2)). Potentiodynamic polarization tests showed that the corrosion current density of the 304L-Cu SS was as much as 4 times lower than that of the 304L SS, indicating that the 304L-Cu SS is a better choice for applications in MIC-prone environments. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Weld solidification cracking in 304 to 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Martinez, Raymond J [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

    2010-01-01

    A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found. This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GT A W showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

  12. Dissimilar welding of nickel-based Alloy 690 to SUS 304L with Ti addition

    Science.gov (United States)

    Lee, H. T.; Jeng, S. L.; Yen, C. H.; Kuo, T. Y.

    2004-10-01

    This study investigates the effects of Ti addition on the weldability, microstructure and mechanical properties of a dissimilar weldment of Alloy 690 and SUS 304L. Shielding metal arc welding (SMAW) is employed to butt-weld two plates with three welding layers, where each layer is deposited in a single pass. To investigate the effects of Ti addition, the flux coatings of the electrodes used in the welding process are modified by varying additions of either a Ti-Fe compound or a Ti powder. The results indicate that the microstructure of the fusion zone (FZ) is primarily dendritic. With increasing Ti content, it is noted that the microstructure changes from a columnar dendritic to an equiaxed dendritic, in which the primary dendrite arm spacing (PDAS) becomes shorter. Furthermore, it is observed that the amount of Al-Ti oxide phase increases in the inter-dendritic region, while the amount of Nb-rich phase decreases. Moreover, the average hardness of the FZ increases slightly. The results indicate that Ti addition prompts a significant increase in the elongation of the weldment (i.e. 36.5%, Ti: 0.41 wt%), although the tensile strength remains relatively unchanged. However, at an increased Ti content of 0.91 wt%, an obvious reduction in the tensile strength is noted, which can be attributed to a general reduction in the weldability of the joint.

  13. Long-Term Effects of Temperature Exposure on SLM 304L Stainless Steel

    Science.gov (United States)

    Amine, Tarak; Kriewall, Caitlin S.; Newkirk, Joseph W.

    2017-11-01

    Austenitic stainless steel is extensively used in industries that operate at elevated temperatures. This work investigates the high-temperature microstructure stability as well as elevated-temperature properties of 304L stainless steel fabricated using the selective laser melting (SLM) process. Significant microstructural changes were seen after a 400°C aging process for as little as 25 h. This dramatic change in microstructure would not be expected based on the ferrite decomposition studied in conventional 304L materials. The as-built additively manufactured alloy has much faster kinetic response to heat treatment at 400°C. An investigation of the structures which occur, the kinetics of the various transformations, and the mechanical properties is presented. The impact of this on the application of SLM 304L is discussed.

  14. Dynamic compressive response of wrought and additive manufactured 304L stainless steels

    Directory of Open Access Journals (Sweden)

    Nishida Erik

    2015-01-01

    Full Text Available Additive manufacturing (AM technology has been developed to fabricate metal components that include complex prototype fabrication, small lot production, precision repair or feature addition, and tooling. However, the mechanical response of the AM materials is a concern to meet requirements for specific applications. Differences between AM materials as compared to wrought materials might be expected, due to possible differences in porosity (voids, grain size, and residual stress levels. When the AM materials are designed for impact applications, the dynamic mechanical properties in both compression and tension need to be fully characterized and understood for reliable designs. In this study, a 304L stainless steel was manufactured with AM technology. For comparison purposes, both the AM and wrought 304L stainless steels were dynamically characterized in compression Kolsky bar techniques. They dynamic compressive stress-strain curves were obtained and the strain rate effects were determined for both the AM and wrought 304L stainless steels. A comprehensive comparison of dynamic compressive response between the AM and wrought 304L stainless steels was performed. SAND2015-0993 C.

  15. Effect of Laser Surface Melting on the Microstructure and Pitting Corrosion Resistance of 304L SS Weldment

    Science.gov (United States)

    Suresh, Girija; Dasgupta, Arup; Kishor, P. S. V. R. A.; Upadhyay, B. N.; Saravanan, T.; Mallika, C.; Mudali, U. Kamachi

    2017-10-01

    The manuscript presents the effect of laser surface melting (LSM) on the microstructural variations and pitting corrosion resistance of 304L SS weldment fabricated by gas tungsten arc welding of 304L SS plates using 308L SS filler wire. The weld region was examined by X-ray radiography for defect detection. LSM of 304L SS weldment was performed using Nd:YAG pulsed laser. Microstructural evaluation was carried out using optical and electron back scatter diffraction techniques. The microstructure of 304L SS base was found to be austenitic, while the weld region of 304L SS weldment contained delta ferrite distributed in austenite matrix. The microstructure of LSM 304L SS weldment was found to be homogeneous austenite matrix with sparsely distributed ferrite. Ferrite measurements showed a decrease in the percentage ferrite in the fusion zone of 304L SS weldment after LSM. A profound enhancement in the pitting corrosion resistance was observed after LSM, which could be attributed to the homogeneous microstructure and decrease in the ferrite content. Pit density was found to be higher in the heat-affected zone of the weldment. Very few pits were observed in the LSM 304L SS weldment compared to the as-weldment.

  16. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Mamede, Anne-Sophie, E-mail: anne-sophie.mamede@ensc-lille.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Nuns, Nicolas, E-mail: nicolas.nuns@univ-lille1.fr [University Lille, CNRS, ENSCL, Centrale Lille, University Artois, UMR 8181 – UCCS – Unité de Catalyse et Chimie du Solide, F-59000 Lille (France); Cristol, Anne-Lise, E-mail: anne-lise.cristol@ec-lille.fr [University Lille, CNRS, Centrale Lille, Arts et Métiers Paris Tech, FRE 3723 – LML – Laboratoire de Mécanique de Lille, F-59000 Lille (France); Cantrel, Laurent, E-mail: laurent.cantrel@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); Souvi, Sidi, E-mail: sidi.souvi@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, PSN-RES, Cadarache, Saint Paul lez Durance, 13115 (France); Laboratoire de Recherche Commun IRSN-CNRS-Lille 1: «Cinétique Chimique, Combustion, Réactivité» (C3R), Cadarache, Saint Paul lez Durance, 13115 (France); and others

    2016-04-30

    Graphical abstract: - Highlights: • Mutitechnique characterisation of oxidised 304L. • Oxidation at high temperature under steam and air conditions of 304L stainless steel. • Chromium and manganese oxides formed in the outer layer. • Oxide profiles differ in air or steam atmosphere. - Abstract: In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8–12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe{sub 2}O{sub 3} oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  17. TESTING OF 304L STAINLESS STEEL IN NITRIC ACID ENVIRONMENTS WITH FLUORIDES AND CHLORIDES

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2010-10-04

    Impure radioactive material processed in nitric acid solutions resulted in the presence of chlorides in a dissolver fabricated from 304L stainless steel. An experimental program was conducted to study the effects of chloride in nitric acid/fluoride solutions on the corrosion of 304L stainless steel. The test variables included temperature (80, 95, and 110 C) and the concentrations of nitric acid (6, 12, and 14 M), fluoride (0.01, 0.1, and 0.2 M) and chloride (100, 350, 1000, and 2000 ppm). The impact of welding was also investigated. Results showed that the chloride concentration alone was not a dominant variable affecting the corrosion, but rather the interaction of chloride with fluoride significantly affected corrosion.

  18. Proton irradiation induced segregation and phase transformation in AISI 304 and AISI 304L stainless steels

    Science.gov (United States)

    Wen-Jen, Liu; Ji-Jung, Kai; Chuen-Horng, Tsai

    1994-09-01

    Three millimeter diameter TEM discs and miniature tensile specimens were irradiated at 420 and 550°C with 5 MeV H +, to doses ranging from 0.01 to 1 dpa. Energy dispersive X-ray (EDX) analysis indicated that significant radiation-induced solute segregation (RIS) occurred near the grain boundary areas in the irradiated 304 specimens. It was found that the ferrite phase formed in the irradiated 304L specimens, and M 23C 6 carbides precipitated along the γ-α interfaces. The CERT results for 304 and 304L specimens indicated that after 1 dpa irradiation the fracture surface was characterized by the distinct IGSCC morphology and SCC embrittlement, respectively, in the irradiated region.

  19. Fatigue Damage Monitoring in 304L Steel Specimens by an Acoustic Emission Method

    Directory of Open Access Journals (Sweden)

    Ould-Amer Ammar

    2014-06-01

    Full Text Available The aim of this work was to clarify fatigue crack initiation and propagation mechanisms in 304L austenitic stainless steel under different total-strain-amplitudes. A complete process from crack initiation and propagation was recorded by using the acoustic emission method in one hand, and replica method in another hand. The effect of strain amplitude on fatigue crack growth was investigated and a new representation of various fatigue curves associated to various levels of fatigue damage is proposed.

  20. Martensitic Transformation in Ultrafine-Grained Stainless Steel AISI 304L Under Monotonic and Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Heinz Werner Höppel

    2012-02-01

    Full Text Available The monotonic and cyclic deformation behavior of ultrafine-grained metastable austenitic steel AISI 304L, produced by severe plastic deformation, was investigated. Under monotonic loading, the martensitic phase transformation in the ultrafine-grained state is strongly favored. Under cyclic loading, the martensitic transformation behavior is similar to the coarse-grained condition, but the cyclic stress response is three times larger for the ultrafine-grained condition.

  1. Multitechnique characterisation of 304L surface states oxidised at high temperature in steam and air atmospheres

    Science.gov (United States)

    Mamede, Anne-Sophie; Nuns, Nicolas; Cristol, Anne-Lise; Cantrel, Laurent; Souvi, Sidi; Cristol, Sylvain; Paul, Jean-François

    2016-04-01

    In case of a severe accident occurring in a nuclear reactor, surfaces of the reactor coolant system (RCS), made of stainless steel (304L) rich in Cr (>10%) and Ni (8-12%), are oxidised. Fission products (FPs) are released from melt fuel and flow through the RCS. A part of them is deposited onto surfaces either by vapour condensation or by aerosol deposition mechanisms. To be able to understand the nature of interactions between these FPs and the RCS surfaces, a preliminary step is to characterize the RSC surface states in steam and air atmosphere at high temperatures. Pieces of 304L stainless steel have been treated in a flow reactor at two different temperatures (750 °C and 950 °C) for two different exposition times (24 h and 72 h). After surfaces analysing by a unique combination of surface analysis techniques (XPS, ToF-SIMS and LEIS), for 304L, the results show a deep oxide scale with multi layers and the outer layer is composed of chromium and manganese oxides. Oxide profiles differ in air or steam atmosphere. Fe2O3 oxide is observed but in minor proportion and in all cases no nickel is detected near the surface. Results obtained are discussed and compared with the literature data.

  2. Comparative Shock Response of Additively Manufactured Versus Conventionally Wrought 304L Stainless Steel*

    Science.gov (United States)

    Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.

    2015-06-01

    Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology allows direct fabrication of metal parts. For the present study, a velocity interferometer (VISAR) measured the time-resolved motion of samples subjected to one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.5 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. Observed differences in shock loading and unloading characteristics for the two 304L source variants have been correlated to complementary Kolsky bar results for compressive and tensile testing at lower strain rates. The effects of composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and sample axis orientation relative to the additive manufacturing deposition trajectory have been assessed to explain differences between the AM and baseline 304L dynamic mechanical properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  3. Evaluation of Mechanical Properties and Fatigue Behavior of STS 304L due to Plastic Working

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hyun-Bo [Yeungnam Univ., Daegu (Korea, Republic of); Kim, Young-Kyun [KOGAS Research Institute, Seoul (Korea, Republic of); Suh, Chang-Min [Kyungpook Nat’l Univ., Daegu (Korea, Republic of)

    2017-07-15

    The purpose of this study is to investigate the influence of the cold reduction rate and an ultrasonic fatigue test (UFT) on the fatigue behaviors of STS 304L. The tensile strength, yield strength, hardness value and fatigue limit in the UFT fatigue test linearly increased as thickness decreased from 1.5 mm to 1.1 mm, as the cold reduction rate of STS 304L increased. As a result of the UFT fatigue test (R = -1) of four specimens, the fatigue limit of the S-N curve formed a knee point in the region of 10{sup 6}, and the 2nd fatigue limit caused by giga cycle fatigue did not appeared. In the case of t = 1.1 mm, the highest fatigue limit was 345 MPa, which was 64.3% higher than the original material (t = 1.5 mm). As a result of the UFT fatigue test of STS 304L, many small surface cracks occurred, grown, coalesced while tearing.

  4. Preparation of high-performance ultrafine-grained AISI 304L stainless steel under high temperature and pressure

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2016-08-01

    Full Text Available Bulk ultra-fine grained (UFG AISI 304L stainless steel with excellent mechanical properties was prepared by a high-temperature and high-pressure (HTHP method using nanocrystalline AISI 304L stainless steel powders obtained from ball milling. Samples were sintered in high-pressure conditions using the highest martensite content of AISI 304L stainless steel powders milled for 25 h. Analyses of phase composition and grain size were accomplished by X-ray diffraction and Rietveld refinement. By comparing the reverse martensite transformation under vacuum and HTHP treat, we consider that pressure can effectively promote the change in the process of transformation. Compared with the solid-solution-treated 304L, the hardness and yield strength of the samples sintered under HTHP are considerably higher. This method of preparation of UFG bulk stainless steel may be widely popularised and used to obtain UFG metallic materials with good comprehensive performance.

  5. Biaxial fatigue tests of notched specimens for AISI 304L stainless steel

    Directory of Open Access Journals (Sweden)

    G. Beretta

    2016-07-01

    Full Text Available High cycle fatigue tests were conducted for stainless steel AISI 304L. The geometry was a thin walled tube with a passing through hole. The tests were axial, torsional and in-phase axial-torsional, all of them under load control with R = −1. The S-N curves were constructed following the ASTM E739 standard and the fatigues limits were calculated following the method of maximum likelihood proposed by Bettinelli. The crack direction along the surface was analysed, with especial attention to the crack initiation zones. The notch fatigue limits for different hole diameters were compared with the predictions done with a microstructural fracture mechanics model.

  6. Comparison of Stress Corrosion Cracking Susceptibility of Laser Machined and Milled 304 L Stainless Steel

    Science.gov (United States)

    Gupta, R. K.; Kumar, Aniruddha; Nagpure, D. C.; Rai, S. K.; Singh, M. K.; Khooha, Ajay; Singh, A. K.; Singh, Amrendra; Tiwari, M. K.; Ganesh, P.; Kaul, R.; Singh, B.

    2016-12-01

    Machining of austenitic stainless steel components is known to introduce significant enhancement in their susceptibility to stress corrosion cracking. The paper compares stress corrosion cracking susceptibility of laser machined 304 L stainless steel specimens with conventionally milled counterpart in chloride environment. With respect to conventionally milled specimens, laser machined specimens displayed more than 12 times longer crack initiation time in accelerated stress corrosion cracking test in boiling magnesium chloride as per ASTM G36. Reduced stress corrosion cracking susceptibility of laser machined surface is attributed to its predominantly ferritic duplex microstructure in which anodic ferrite phase was under compressive stress with respect to cathodic austenite.

  7. Crack propagation in stainless steel AISI 304L in Hydrogen Chemistry conditions (HWC); Propagacion de Grietas en Acero Inoxidable AISI 304L en Condiciones de Quimica de Hidrogeno (HWC)

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Fuentes C, P.; Merino C, F. [ININ, Carretera Mexico -Toluca s/n, La Marquesa, Ocoyoacac, Mexico (Mexico); Castano M, V. [Instituto de Fisica Aplicada, UNAM, Km 15.5 Carretera Queretaro-San Luis Potosi, Juriquilla, Queretaro (Mexico)]. e-mail: ads@nuclear.inin.mx

    2006-07-01

    Velocities of crack growth in samples type CT pre cracking of stainless steel AISI 304l solder and sensitized thermally its were obtained by the Rising Displacement method or of growing displacement. It was used a recirculation circuit that simulates the operation conditions of a BWR type reactor (temperature of 280 C and a pressure of 8 MPa) with the chemistry modified by the addition of hydrogen with and without the addition of impurities of a powerful oxidizer like the Cu{sup +} ion. In each essay stayed a displacement velocity was constant of 1x10{sup -9} m/s, making a continuous pursuit of the advance of the crack by the electric potential drop technique. Contrary to the idea of mitigation of the crack propagation velocity by effect of the addition of the hydrogen in the system, the values of the growth velocities obtained by this methodology went similar to the opposing ones under normal operation conditions. To the finish of the rehearsal one carries out the fractographic analysis of the propagation surfaces, which showed cracks growth in trans and intergranular way, evidencing the complexity of the regulator mechanisms of the IGSCC like in mitigation conditions as the alternative Hydrogen Chemistry. (Author)

  8. Comparative shock response of additively manufactured versus conventionally wrought 304L stainless steel

    Science.gov (United States)

    Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.; Palmer, T. A.

    2017-01-01

    Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens that were machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology permits direct fabrication of net- or near-net-shape metal parts. For the present investigation, velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response for one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.0 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. The possible contributions of various factors, such as composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and/or sample axis orientation relative to the additive manufacturing deposition trajectory, are considered to explain differences between the AM and baseline 304L dynamic material results.

  9. Dependence of corrosion properties of AISI 304L stainless steel on the austenite grain size

    Energy Technology Data Exchange (ETDEWEB)

    Sabooni, Soheil; Rashtchi, Hamed; Eslami, Abdoulmajid; Karimzadeh, Fathallah; Enayati, Mohammad Hossein; Raeissi, Keyvan; Imani, Reihane Faghih [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of). Dept. of Materials Engineering; Ngan, Alfonso Hing Wan [The Univ. of Hong Kong (China). Dept. of Mechanical Engineering

    2017-07-15

    The corrosion resistance of austenitic stainless steels is known to be hampered by the loss of chromium available for passive surface layer formation as a result of chromium carbide precipitation at austenite grain boundaries during annealing treatments. Although high-temperature annealing can promote carbide dissolution leading to better corrosion resistance, grain coarsening also results, which would lead to poorer mechanical properties. Processing methods to achieve both good corrosion resistance and mechanical properties are thus highly desirable for austenitic stainless steels. In the present study, we show that the corrosion resistance of AISI 304L stainless steel can be improved by grain refinement into the ultrafine-grained regime. Specifically, samples with different austenite grain sizes in the range of 0.65-12 μm were studied by potentiodynamic polarization and electrochemical impedance spectroscopy tests in a 3.5 wt.% NaCl solution. All samples showed a typical passive behavior with similar corrosion potential, but the corrosion current density decreased significantly with decreasing grain size. The results show that the sample with the finest grain size had the best corrosion resistance due to a higher resistance of the passive layer to pitting attacks. This study indicates that grain refinement which improves mechanical properties can also significantly improve the corrosion resistance of AISI 304L stainless steel.

  10. Propagation of crevices in stainless steel AISI304L in conditions of hydrogen chemistry (HWC); Propagacion de grietas en acero inoxidable AISI304L en condiciones de quimica de hidrogeno (HWC)

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Fuentes C, P.; Merino C, F. [ININ, 52750 Ocoyoacac, Estado de Mexico (Mexico); Castano M, V. [IFA-UNAM, Juriquilla, Queretaro (Mexico)]. e-mail: ads@nuclear.inin.mx

    2006-07-01

    Crevice growth velocities in samples of AISI 304L stainless steel thermally welded and sensitized were obtained by the Rising displacement method or of growing displacement. It was used a recirculation circuit in where the operation conditions of a BWR type reactor were simulated (temperature of 288 C and a pressure of 8 MPa) with the chemistry modified by the addition of hydrogen with and without the addition of impurities of a powerful oxidizer like the Cu{sup ++} ion. CT pre cracked specimens were used and each rehearsal stayed to one constant displacement velocity of 1 x 10{sup -9} m/s (3.6 {mu}m/hr), making a continuous pursuit of the advance of the crack by the electric potential drop technique. To the end of the rehearsal it was carried out the fractographic analysis of the propagation surfaces. The values of the growth velocities obtained by this methodology went similar to the opposing ones under normal conditions of operation; while the fractographic analysis show the cracks propagation in trans and intergranular ways, evidencing the complexity of the regulator mechanisms of the one IGSCC even under controlled ambient conditions or with mitigation methodologies like the alternative hydrogen chemistry. (Author)

  11. Effect of Nitrogen Addition in 304 L Stainless Steel on the IGSCC Crack Growth Rate in Simulated BWR Environment

    Science.gov (United States)

    Roychowdhury, S.; Kain, V.; Prasad, R. C.

    Intergranular Stress Corrosion Cracking (IGSCC) in austenitic Stainless Steels (SS) in Boiling Water Reactor (BWR) operating conditions have been reported worldwide. Nitrogen containing Stainless Steel is used in BWRs and it can affect IGSCC behavior. In this investigation type 304L stainless steel with two different levels of nitrogen was evaluated in the sensitized and non-sensitised strain-hardened condition. Experiments were carried out in high temperature water with controlled dissolved oxygen. In the sensitised condition, the Crack Growth Rate (CGR) reduced and in the non-sensitised strain-hardened condition the CGR increased with increase in nitrogen level in SS. Transmission electron microscopic (TEM) investigations of the as-rolled SS and the SS after tensile testing at 288 °C indicated that rolling resulted in higher grain boundary strain which is a possible cause for higher CGR in the SS with higher nitrogen. Nitrogen did not have a noticeable effect on the deformation mechanism, for the SS after tensile testing at 288 °C, and the dislocation structures observed were similar for both the SS.

  12. Evaluation of stress corrosion cracking susceptibility of stainless steel 304L with surface nanocrystallization by small punch test

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Tao; Chen, Peng [The Key Laboratory of Safety Science of Pressurized System, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Guan, Kaishu, E-mail: guankaishu@ecust.edu.cn [The Key Laboratory of Safety Science of Pressurized System, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2013-01-20

    In this study, the small punch test (SPT) was conducted to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steel (SS) 304L with surface nanocrystallization (SNC) in 1 mol/L NaCl+0.5 mol/L HCl aq. The surface mechanical attrition treatment (SMAT) was applied to realize the SNC. The mechanical property and micro-structural evolutions of SS 304L induced by SMAT were investigated through optical microscope (OM), X-ray diffraction (XRD), micro-Vickers hardness and transmission electron microscopy (TEM). The grain size on the surface of the material was reduced to 30-100 nm. The SPT was conducted in both ambient air and corrosive solution. The results were investigated by OM and scanning electron microscopy (SEM), showing that in ambient air, the specimen with 30 min SMAT performed a higher yield strength and lower ductility than the solution annealed (SA) counterpart. The SS 304L without SMAT presented a transgranular SCC (TGSCC) mode in chloride solution. In contrast, the SNC 304L SS showed a higher SCC susceptibility with a typical intergranular SCC (IGSCC).

  13. Stress Corrosion Cracking Susceptibility of 304L Substrate and 308L Weld Metal Exposed to a Salt Spray

    Directory of Open Access Journals (Sweden)

    Chia-Hao Hsu

    2017-02-01

    Full Text Available 304 stainless steels (SS were considered as the materials for a dry storage canister. In this study, ER (Electrode Rod 308L was utilized as the filler metal for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. The electron backscatter diffraction (EBSD map was used to identify the inherent microstructures in distinct specimens. U-bend and weight-loss tests were conducted by testing the 304L substrates and welds in a salt spray containing 5 wt % NaCl at 80 °C to evaluate their susceptibility to stress corrosion cracking (SCC. Generally, the weight loss of the ER 308L deposit was higher than that of the 304L substrate in a salt spray in the same sample-prepared condition. The dissolution of the skeletal structure in the fusion zone (FZ was responsible for a greater weight loss of the 308L deposit, especially for the cold-rolled and sensitized specimen. Cold rolling was detrimental and sensitization after cold rolling was very harmful to the SCC resistance of the 304L substrate and 308L deposit. Overall, the SCC susceptibility of each specimen was correlated with its weight loss in each group.

  14. Gas tungsten arc welding and friction stir welding of ultrafine grained AISI 304L stainless steel: Microstructural and mechanical behavior characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sabooni, S., E-mail: s.sabooni@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Karimzadeh, F.; Enayati, M.H. [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of); Ngan, A.H.W. [Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Jabbari, H. [Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan (Iran, Islamic Republic of)

    2015-11-15

    In the present study, an ultrafine grained (UFG) AISI 304L stainless steel with the average grain size of 650 nm was successfully welded by both gas tungsten arc welding (GTAW) and friction stir welding (FSW). GTAW was applied without any filler metal. FSW was also performed at a constant rotational speed of 630 rpm and different welding speeds from 20 to 80 mm/min. Microstructural characterization was carried out by High Resolution Scanning Electron Microscopy (HRSEM) with Electron Backscattered Diffraction (EBSD) and Transmission Electron Microscopy (TEM). Nanoindentation, microhardness measurements and tensile tests were also performed to study the mechanical properties of the base metal and weldments. The results showed that the solidification mode in the GTAW welded sample is FA (ferrite–austenite) type with the microstructure consisting of an austenite matrix embedded with lath type and skeletal type ferrite. The nugget zone microstructure in the FSW welded samples consisted of equiaxed dynamically recrystallized austenite grains with some amount of elongated delta ferrite. Sigma phase precipitates were formed in the region ahead the rotating tool during the heating cycle of FSW, which were finally fragmented into nanometric particles and distributed in the weld nugget. Also there is a high possibility that the existing delta ferrite in the microstructure rapidly transforms into sigma phase particles during the short thermal cycle of FSW. These suggest that high strain and deformation during FSW can promote sigma phase formation. The final austenite grain size in the nugget zone was found to decrease with increasing Zener–Hollomon parameter, which was obtained quantitatively by measuring the peak temperature, calculating the strain rate during FSW and exact examination of hot deformation activation energy by considering the actual grain size before the occurrence of dynamic recrystallization. Mechanical properties observations showed that the welding

  15. Zirconium oxide deposits (ZrO{sub 2}) and titanium oxide (TiO{sub 2}) on 304l stainless steel; Depositos de oxido de circonio (ZrO{sub 2}) y oxido de titanio (TiO{sub 2}) sobre acero inoxidable 304L

    Energy Technology Data Exchange (ETDEWEB)

    Davila N, M. L.

    2015-07-01

    This research project aims to carry out the surface and electrochemical characterization to obtain the optimum conditions of the hydrothermal deposits of zirconium oxide ZrO{sub 2} (baddeleyite) and titanium oxide TiO{sub 2} (anatase and rutile phases) on 304l stainless steel, simulating an inhibiting protective layer. 304l steel specimens were cut, pre-oxidized in water at a temperature of 288 degrees Celsius and 8 MPa, similar to those of a typical BWR conditions. From the titanium oxide anatase crystalline phase, the rutile phase was obtained by a heat treatment at 1000 degrees Celsius. The Sigma-Aldrich pre-oxidized powders and steel 304l were characterized using techniques of X-ray diffraction, scanning electron microscopy, X-ray dispersive energy, chemical mapping and Raman spectrometry. The pre-oxidized steel has two oxide layers, an inner layer with nano metric crystals and another outer of larger crystals to 1μm, with the formation of hematite and magnetite, this predominating. The surface that contacted the sample holder has larger crystals. Hydrothermal deposits were carry out from suspensions of 10, 100 and 1000 ppm, of the crystal phases of anatase, rutile and baddeleyite, on the pre-oxidized steel at a temperature of 150 degrees Celsius for 2 and 7 days, samples were analyzed by X-ray diffraction, scanning electron microscopy, X-ray dispersive energy, Raman spectrometry and Tafel polarization. The suspension to 1000 ppm for 7 days coated surface most; the baddeleyite deposit is noticed more homogeneous than anatase and rutile. The deposit is favored when hematite and magnetite crystals are larger. The chemical mapping on deposits show that even after being immersed in water to 288 degrees Celsius during 30 days, the deposits are still present although a loss is observed. A reference electrode was assembled to conduct electrochemical tests of Tafel able to withstand a temperature of 288 degrees Celsius and pressure of 8 MPa. The baddeleyite deposit

  16. Correlation between Corrosion Potential and Pitting Potential for AISI 304L Austenitic Stainless Steel in 3.5% NaCl Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Alonso-Falleiros Neusa

    2002-01-01

    Full Text Available We investigated the effect of surface finish of two AISI 304L (UNS S30403 stainless steels on the corrosion potential (Ecorr in 3.5% NaCl aqueous solution and its value was compared with the pitting potential (Ep value and the type of anodic potentiodynamic curve obtained for determination of Ep in this solution. Five different surface finishes were examined. Ecorr and its standard deviation are strongly affected by the type of surface finish. Moreover, there are evidences of a linear correlation between Ecorr and Ep, as well as between the percentage of anodic curves with a well-defined pitting potential and the uncertainty in the determination of Ecorr.

  17. Modelling of cyclic plasticity for austenitic stainless steels 304L, 316L, 316L(N)-IG

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Palma, Mauro, E-mail: mauro.dallapalma@igi.cnr.it

    2016-11-01

    Highlights: • Stress-strain amplitudes of cyclic stress strain curves defined by design codes are provided as reference data. • A macroinstruction simulating cyclic plasticity and producing hardening parameters of constitutive models is developed. • Hardening parameters of the nonlinear Chaboche model are provided for stainless steels 316l-N, 316L, 304L at different temperatures. • Ratcheting is simulated by using the produced hardening parameters. - Abstract: The integrity assessment of structures subjected to cyclic loading must be verified with regard to cyclic type damage including time-independent fatigue and progressive deformation or ratcheting. Cyclic damage is verified simulating the material elastic-plastic loop and looking at the accumulated net plastic strain during each cycle at all points of the structure subjected to the complete time history of loadings. This work deals with the development of a numerical model producing the Chaboche hardening parameters starting from stress-strain data produced by testing of materials. Then, the total plastic strain can be simulated using the Chaboche inelastic constitutive model requested for finite element analyses. This is particularly demanding for pressure vessels, pressurised piping, boilers, and mechanical components of nuclear installations made of stainless steels. A design optimisation by iterative analyses is developed to approach the stress-strain test data with the Chaboche model. The parameters treated as design variables are the Chaboche parameters and the objective function to be minimised is a combination of the deviations from test data. The optimiser calls a macroinstruction simulating cyclic loading of a sample for different material temperatures. The numerical model can be used to produce hardening parameters of materials for inelastic finite element verifications of structures with complex joints like elbows subjected to a combination of steady sustained and cyclic loads.

  18. Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65; Estudio comparativo de la corrosion inducida por microorganismos sulfatorreductores, en un acero inoxidable 304L sensibilizado y un acero al carbono API X65

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Gonzalez F, E.; Arganis J, C.; Luna C, P.; Carapia M, L. [ININ, Carretera Mexico-Toluca Km. 36.5, 52045 Estado de Mexico (Mexico)]. e-mail: ads@nuclear.inin.mx

    2004-07-01

    In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

  19. Deposition and characterization of noble metal onto surfaces of 304l stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Arganis J, C. R.; Aguilar T, J. A.; Medina A, A. L., E-mail: aida.contreras@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-10-15

    Noble metal chemical addition (NMCA) plus hydrogen water chemistry is an industry-wide accepted approach for potential intergranular stress corrosion cracking mitigation of BWR internals components. NMCA is a method of applying noble metal onto BWR internals surfaces using reactor water as the transport medium that causes the deposition of noble metal from the liquid onto surfaces. In this work different platinum concentration solutions were deposited onto pre-oxidized surfaces of 304l steel at 180 C during 48 hr in an autoclave. In order to simulate the zinc water conditions, deposits of Zn and Pt-Zn were also carried out. The solutions used to obtain the deposits were: sodium hexahydroxyplatinate (IV), zinc nitrate hydrate and zinc oxide. The deposits obtained were characterized by scanning electron microscopy and X-ray diffraction. Finally, the electrochemical corrosion potential of pre-oxidized samples with Pt deposit were obtained and compared with the electrochemical corrosion potential of only pre-oxidized samples. (Author)

  20. Development of Nanocrystalline 304L Stainless Steel by Large Strain Cold Working

    Directory of Open Access Journals (Sweden)

    Marina Odnobokova

    2015-04-01

    Full Text Available The microstructural changes leading to nanocrystalline structure development and the respective tensile properties were studied in a 304L stainless steel subjected to large strain cold rolling at ambient temperature. The cold rolling was accompanied by the development of deformation twinning and martensitic transformation. The latter readily occurred at deformation microshear bands, leading the martensite fraction to approach 0.75 at a total strain of 3. The deformation twinning followed by microshear banding and martensitic transformation promoted the development of nanocrystalline structure consisting of a uniform mixture of austenite and martensite grains with their transverse sizes of 120–150 nm. The developed nanocrystallites were characterized by high dislocation density in their interiors of about 3 × 1015 m−2 and 2 × 1015 m−2 in austenite and martensite, respectively. The development of nanocrystalline structures with high internal stresses led to significant strengthening. The yield strength increased from 220 MPa in the original hot forged state to 1600 MPa after cold rolling to a strain of 3.

  1. Atmospheric pitting corrosion of 304L stainless steel: the role of highly concentrated chloride solutions.

    Science.gov (United States)

    Street, Steven R; Mi, Na; Cook, Angus J M C; Mohammed-Ali, Haval B; Guo, Liya; Rayment, Trevor; Davenport, Alison J

    2015-01-01

    The morphology of atmospheric pitting corrosion in 304L stainless steel plate was analysed using MgCl(2) droplets in relation to changes in relative humidity (RH) and chloride deposition density (CDD). It was found that highly reproducible morphologies occur that are distinct at different RH. Pitting at higher concentrations, i.e. lower RH, resulted in satellite pits forming around the perimeter of wide shallow dish regions. At higher RH, these satellite pits did not form and instead spiral attack into the shallow region was observed. Increasing CDD at saturation resulted in a very broad-mouthed pitting attack within the shallow dish region. Large data sets were used to find trends in pit size and morphology in what is essentially a heterogeneous alloy. Electrochemical experiments on 304 stainless steel wires in highly saturated solutions showed that the passive current density increased significantly above 3 M MgCl(2) and the breakdown pitting potential dropped as the concentration increased. It is proposed that the shallow dish regions grow via enhanced dissolution of the passive film, whereas satellite pits and a spiral attack take place with active dissolution of bare metal surfaces.

  2. Effect of Grain Size on the Corrosion Behavior of 304L Stainless Steel

    Directory of Open Access Journals (Sweden)

    M. Atapour

    2016-03-01

    Full Text Available In this investigation, the effect of grain size on the corrosion behavior of 304L stainless steel has been studied. Samples with grain sizes of 0.5, 3 and 12 micrometers were fabricated through formation of strain-induced martensite by 80% cold rolling of the stainless steel sheets at -15 °C and its reversion to austenite during annealing at 900 °C for 1, 5 and 180 min. The corrosion behavior of samples with different grain sizes was investigated by cyclic polarization experiments and  immersion tests in 0.1 M hydrochloric acid (HCl. The polarisation tests showed no differences in uniform corrosion rates of the samples. The results of the cyclic polarisation and immersion tests showed that decreasing the grain size improved the pitting corrosion resistance from 290 mVAg/Agcl for grain size of 12 micrometers to 420 mVAg/Agcl for grain size of 0.5 micrometers.

  3. Influence of substrate bias voltage on the properties of TiO{sub 2} deposited by radio-frequency magnetron sputtering on 304L for biomaterials applications

    Energy Technology Data Exchange (ETDEWEB)

    Bait, L. [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria); Azzouz, L. [Université de Amar Telidji, Laghouat (Algeria); Madaoui, N. [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria); Saoula, N., E-mail: nsaoula@cdta.dz [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria)

    2017-02-15

    Highlights: • TiO{sub 2} films were deposited on stainless steel 304L RF magnetron sputtering at different substrate bias. • The hardness of TiO{sub 2} coated 304L are higher than those obtained for uncoated substrate. • TiO{sub 2} films provide good protection for stainless steel against corrosion in Ringer solution. - Abstract: The aim of this paper is to investigate the effect of the substrate bias, varied from 0 to −100 V, on the structure and properties of the TiO{sub 2} thin films for biomaterials applications. The TiO{sub 2} films were grown onto 304L stainless steel substrate using radio-frequency (rf) magnetron sputtering from a pure titanium target in Ar-O{sub 2} gas mixture. The variation of substrate bias voltage from 0 to −100 V produces variations of structure and mechanical properties of the films. The deposited films were characterized by X-rays diffraction, nanoindentation and potentiodynamic polarization. Also, the friction and wear properties of TiO{sub 2} films sliding against alumina ball in air were investigated. Experimental results showed that the thickness increases for non-biased substrate voltage to Vs = −100 V from 820 nm to 1936 nm respectively. The roughness is in the range of 50 nm and 14 nm. XRD results show that all structures of the films are crystalline and changed with varying the bias voltage. The anatase phase is predominant in the low negative bias range (0–50 V). The hardness significantly increased from 2.2 to 6.4 GPa when the bias voltage was increased from 0 to 75 V and then slightly decrease to 5.1 GPa as further increased to 100 V. At the same time, the results indicate that TiO{sub 2} films deposited at −100 V exhibited better wear resistance compared to the other samples, i.e. the minimum wear rates and the lower coefficient of friction of 0.16. In order to simulate natural biological conditions, physiological serum (pH = 6.3), thermostatically controlled at 37 °C, was used as the electrolyte for the

  4. Full field modeling of dynamic recrystallization in a global level set framework, application to 304L stainless steel

    Directory of Open Access Journals (Sweden)

    Boulais-Sinou Romain

    2016-01-01

    Full Text Available A new full field numerical approach for the simulation of dynamic and post-dynamic recrystallization will be detailed. A level Set framework is employed to link a crystal plasticity finite element method with the modeling of recrystallization. Plasticity is calculated through the activation of slip systems and provides predictions for both SSDs and GNDs densities. These predictions control the activation and kinetics of recrystallization. All the developments are applied on 304L stainless steel.

  5. L2 Milestone 5433: Characterization of Dynamic Behavior of AM and Conventionally Processed Stainless Steel (316L and 304L)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, George Thompson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Livescu, Veronica [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rigg, P. A. [Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics; Trujillo, Carl Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cady, Carl McElhinney [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Shuh-Rong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carpenter, John S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lienert, Thomas J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fensin, Saryu Jindal [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Knapp, Cameron M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beal, Roberta Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morrow, Benjamin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dippo, Olivia F. [Univ. of California, San Diego, CA (United States); Jones, David Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Daniel Tito [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Valdez, James Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-26

    For additive manufacturing (AM) of metallic materials, the certification and qualification paradigm needs to evolve as there currently exists no broadly accepted “ASTM- or DIN-type” additive manufacturing certified process or AM-material produced specifications. Accordingly, design, manufacture, and thereafter implementation and insertion of AM materials to meet engineering applications requires detailed quantification of the constitutive (strength and damage) properties of these evolving materials, across the spectrum of metallic AM methods, in comparison/contrast to conventionally-manufactured metals and alloys. This report summarizes the 316L SS research results and presents initial results of the follow-on study of 304L SS. For the AM-316L SS investigation, cylindrical samples of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS was characterized in both the “as-built” Additively Manufactured state and following a heat-treatment designed to obtain full recrystallization to facilitate comparison with annealed wrought 316L SS. The dynamic shock-loading-induced damage evolution and failure response of all three 316L SS materials was quantified using flyer-plate impact driven spallation experiments at peak stresses of 4.5 and 6.35 GPa. The results of these studies are reported in detail in the first section of the report. Publication of the 316L SS results in an archival journal is planned. Following on from the 316L SS completed work, initial results on a study of AM 304L SS are in progress and presented herein. Preliminary results on the structure/dynamic spallation property behavior of AM-304L SS fabricated using both the directed-energy LENS and an EOS powder-bed AM techniques in comparison to wrought 304L SS is detailed in this Level 2 Milestone report.

  6. Experimental investigation of Ti–6Al–4V titanium alloy and 304L stainless steel friction welded with copper interlayer

    Directory of Open Access Journals (Sweden)

    R. Kumar

    2015-03-01

    Full Text Available The basic principle of friction welding is intermetallic bonding at the stage of super plasticity attained with self-generating heat due to friction and finishing at upset pressure. Now the dissimilar metal joints are especially popular in defense, aerospace, automobile, bio-medical, refinery and nuclear engineerings. In friction welding, some special alloys with dual phase are not joined successfully due to poor bonding strength. The alloy surfaces after bonding also have metallurgical changes in the line of interfacing. The reported research work in this area is scanty. Although the sound weld zone of direct bonding between Ti–6Al–4V and SS304L was obtained though many trials, the joint was not successful. In this paper, the friction welding characteristics between Ti–6Al–4V and SS304L into which pure oxygen free copper (OFC was introduced as interlayer were investigated. Box–Behnken design was used to minimize the number of experiments to be performed. The weld joint was analyzed for its mechanical strength. The highest tensile strength between Ti–6Al–4V and SS304L between which pure copper was used as insert metal was acquired. Micro-structural analysis and elemental analysis were carried out by EDS, and the formation of intermetallic compound at the interface was identified by XRD analysis.

  7. Comparative study of the microbiological corrosion among an AISI 304L and an API X65; Estudio comparativo de la corrosion microbiologica entre un AISI 304L y un API X65

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Arganis J, C.; Luna C, P.; Carapia M, L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Gonzalez F, E. [ITT, Toluca, Estado de Mexico (Mexico)

    2004-07-01

    Metallic samples of AISI 304L sensitized and API X65, were subjected to the action of an inoculated media with reductive sulphate microorganisms (SBR), carrying out electrochemical evaluations by means of the techniques of Polarization Resistance (RP), Tafel extrapolation (ET) and Electrochemical Noise (RE). The generated information was complemented with the analysis and diagnostic of the present damage in the surfaces exposed in both metals. The used electrochemical techniques allow to determine the corrosion velocities associated to each system, establishing that the uniform corrosion is not affected by the effect of the microorganisms; however, electrochemical noise, evidenced the formation of stings associated to the presence of bacteria. (Author)

  8. Corrosion behavior of mild steel and SS 304L in presence of dissolved nickel under aerated and deaerated conditions

    Directory of Open Access Journals (Sweden)

    Mohd Mobin

    2011-12-01

    Full Text Available In dual purpose water/power co-generation plants, the presence of high concentration of Cu and Ni in the re-circulating brine/condensate as a result of condenser tubes corrosion has been attributed as one of the several causes of corrosion damage of flash chamber materials and water touched parts of the boilers. The present investigation deals with the effect of dissolved nickel in the concentration range of 10 ppb to 100 ppm on the corrosion behavior of mild steel and SS 304L in two aqueous medium namely, distilled water and artificial seawater. The effect of pH, dissolved oxygen and flow condition of aqueous medium on the corrosion behavior was also monitored. The experimental techniques include immersion test and electrochemical tests which include free corrosion potential measurements and potentiodynamic polarization measurements. The corrosion rate of mild steel and SS 304L under different experimental conditions was determined by weight loss method and spectrophotometric determination of iron ion entered into the test solution during the period of immersion. The pH of the test solution was also monitored during the entire period of immersion. The left over nickel ions present in the test solution after completion of immersion was also estimated using Atomic Absorption Spectrophotometer. The surface morphology of the corroded steel surface was also examined using scanning electron microscopy (SEM. The results of the studies show that SS 304L largely remains unaffected in both distilled water and artificial seawater under different experimental conditions. However, the effect of nickel on the corrosion behavior of mild steel is quite pronounced and follows interesting trends.

  9. Corrosion behavior of mild steel and SS 304L in presence of dissolved nickel under aerated and deaerated conditions

    OpenAIRE

    Mohd Mobin; Hina Shabnam

    2011-01-01

    In dual purpose water/power co-generation plants, the presence of high concentration of Cu and Ni in the re-circulating brine/condensate as a result of condenser tubes corrosion has been attributed as one of the several causes of corrosion damage of flash chamber materials and water touched parts of the boilers. The present investigation deals with the effect of dissolved nickel in the concentration range of 10 ppb to 100 ppm on the corrosion behavior of mild steel and SS 304L in two aqueous ...

  10. Optimization of tensile strength of friction welded AISI 1040 and AISI 304L steels according to statistics analysis (ANOVA)

    Energy Technology Data Exchange (ETDEWEB)

    Kirik, Ihsan [Batman Univ. (Turkey); Ozdemir, Niyazi; Firat, Emrah Hanifi; Caligulu, Ugur [Firat Univ., Elazig (Turkey)

    2013-06-01

    Materials difficult to weld by fusion welding processes can be successfully welded by friction welding. The strength of the friction welded joints is extremely affected by process parameters (rotation speed, friction time, friction pressure, forging time, and forging pressure). In this study, statistical values of tensile strength were investigated in terms of rotation speed, friction time, and friction pressure on the strength behaviours of friction welded AISI 1040 and AISI 304L alloys. Then, the tensile test results were analyzed by analysis of variance (ANOVA) with a confidence level of 95 % to find out whether a statistically significant difference occurs. As a result of this study, the maximum tensile strength is very close, which that of AISI 1040 parent metal of 637 MPa to could be obtained for the joints fabricated under the welding conditions of rotation speed of 1700 rpm, friction pressure of 50 MPa, forging pressure of 100 MPa, friction time of 4 s, and forging time of 2 s. Rotation speed, friction time, and friction pressure on the friction welding of AISI 1040 and AISI 304L alloys were statistically significant regarding tensile strength test values. (orig.)

  11. In situ study by atomic force microscopy of localised corrosion on a 304L stainless steel; Etude in situ par microscopie a force atomique de la corrosion localisee d'un acier inoxydable 304L

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F

    2005-12-15

    At this time, the understanding of the initiation of localized corrosion on stainless steels (SS) is still limited. In this context, the present work aimed at observing in situ by Atomic Force Microscopy (AFM) the initiation of corrosion pits and stress corrosion cracking (SCC) cracks. In order to complete the project, a new technique associating an AFM, an electrochemical cell and a traction platform as been developed. It allows in situ imaging of the surface evolutions of a 304L SS at the nano-scale. under controlled potential and/or under stress conditions. We show that corrosion pits initiate preferentially in relation with nano-metric defects of the surface. For the first time, a real-time kinetic study of the first steps of nano-metric pits growth has been performed. This study corroborates the 'point-defect' model (vertical pit growth speed of 0.18 angstrom.s{sup -1}, current densities inside pits evaluated to 73 {mu}jA.cm{sup -2}. Combined with the EBSD technique (Electron Backscattered Diffraction), the AFM allows a total indexing of the activated slip systems during deformation and give information about the number of emerged dislocations (few units). The effect of strain hardening at the nano-scale on pitting susceptibility has been investigated: 70% of the pits set up at strain hardened areas. To explain this phenomenon, we propose a simple model based on the modification of the local work function of the surface due to local stress gradients. Concerning SCC, the first in situ observations seem to validate Magnin's mechanism: crack initiation appears at strain concentration spots. Observed after anodization of our 304L surface, organized arrays of nano-cavities (period of 50-100 nm) have been analyzed. In collaboration with an INSERM team, we showed that such nano-structured surfaces increase the adhesion and differentiation of bone cells. (author)

  12. Effect of Composition on the Formation of Delta Ferrite in 304L Austenitic Stainless Steels During Hot Deformation

    Science.gov (United States)

    Soleymani, S.; Ojo, O. A.; Richards, N.

    2015-01-01

    Four different AISI 304L austenitic stainless steels with chromium equivalent-to-nickel equivalent (Creq/Nieq) ratios of 1.57, 1.59, 1.62, and 1.81 were chosen for this study. The influence of chemical composition on solid-state formation of delta ferrite phase during hot deformation was investigated. Compression tests were performed at temperature, strain, and strain rate ranges of 1200 to 1300 °C, 10 to 70%, and 0.1 to 10 s-1, respectively. Increasing the temperature, strain, and strain rate led to increased formation of delta ferrite. The results show that the formation of delta ferrite during hot deformation is also strongly dependent on chemical composition. The higher the Creq/Nieq ratio, the higher the tendency for the formation of delta ferrite. The observed behavior may be attributed to plastic deformation-induced formation of crystallographic defects such as dislocations affecting the diffusion rate.

  13. Effect of cold deformation on the electrochemical behaviour of 304L stainless steel in contaminated sulfuric acid environment

    Science.gov (United States)

    Luo, Hong; Su, Huaizhi; Ying, Guobing; Dong, Chaofang; Li, Xiaogang

    2017-12-01

    The effect of cold deformation on the microstructure and electrochemical corrosion behaviour of 304L stainless steel in contaminated sulfuric acid solutions (simulated proton exchange membrane fuel cells environments) were evaluated using electron backscatter diffraction analyses, electrochemical measurements, and surface analyses. The internal microstructure,including the grain sizes, angles of the grain boundaries, low coincidence site lattice boundaries, and phase transformations, was changed due to the cold deformation. No noticeable modifications of the pitting corrosion potential were observed during the various deformations, except for a slight enhancement in the passive current density with an increase in the deformation. The CrO3 and metal Ni species in the passive film were investigated after deformation. After heavy deformation (greater than 60%), nickel oxides were detected. Moreover, the Cr/Fe and O2-/OH- ratios in the passive film were higher before deformation, and they decreased with an increase in the deformation level.

  14. Experimental and numerical study on optimization of the single point incremental forming of AINSI 304L stainless steel sheet

    Science.gov (United States)

    Saidi, B.; Giraud-Moreau, L.; Cherouat, A.; Nasri, R.

    2017-09-01

    AINSI 304L stainless steel sheets are commonly formed into a variety of shapes for applications in the industrial, architectural, transportation and automobile fields, it’s also used for manufacturing of denture base. In the field of dentistry, there is a need for personalized devises that are custom made for the patient. The single point incremental forming process is highly promising in this area for manufacturing of denture base. The single point incremental forming process (ISF) is an emerging process based on the use of a spherical tool, which is moved along CNC controlled tool path. One of the major advantages of this process is the ability to program several punch trajectories on the same machine in order to obtain different shapes. Several applications of this process exist in the medical field for the manufacturing of personalized titanium prosthesis (cranial plate, knee prosthesis...) due to the need of product customization to each patient. The objective of this paper is to study the incremental forming of AISI 304L stainless steel sheets for future applications in the dentistry field. During the incremental forming process, considerable forces can occur. The control of the forming force is particularly important to ensure the safe use of the CNC milling machine and preserve the tooling and machinery. In this paper, the effect of four different process parameters on the maximum force is studied. The proposed approach consists in using an experimental design based on experimental results. An analysis of variance was conducted with ANOVA to find the input parameters allowing to minimize the maximum forming force. A numerical simulation of the incremental forming process is performed with the optimal input process parameters. Numerical results are compared with the experimental ones.

  15. A new type of EM wave absorbing coating

    Science.gov (United States)

    Gauss, A., Jr.

    1982-06-01

    Research on radar anti-reflection coatings has been actively pursued both theoretically and experimentally since World War II. Interference, (1,2) dielectric (3), and magnetic-dielectric (4,5) absorptive coatings have been tried. Recently a new type of radar absorbing chaff (RAC) has been suggested (6). Calculations done at BRL indicate that by compacting the RAC filaments a new type of radar absorbing coating (called RACO) may be possible. The filaments would be fixed in a solid binder having near unity dielectric constant. The primary mechanism for attenuation of the incident radiation by a RAC cloud or RACO layer is by resistive dissipation in the relatively long, thin chaff filaments. The tiny RAC-RACO filaments have length to diameter ratios on the order of one thousand with diameters of about 500A. Filament separations in a RACO are about one-half to one-third of a filament length thus requiring the inclusion of dipole and perhaps higher order interactions. Each filament can be modeled simply as a series resistive-capacitive circuit, single filament theory will be discussed in Section 2.

  16. Low cycle fatigue: high cycle fatigue damage accumulation in a 304L austenitic stainless steel; Endommagement et cumul de dommage en fatigue dans le domaine de l'endurance limitee d'un acier inoxydable austenitique 304L

    Energy Technology Data Exchange (ETDEWEB)

    Lehericy, Y

    2007-05-15

    The aim of this study was to evaluate the consequences of a Low Cycle Fatigue pre-damage on the subsequent fatigue limit of a 304L stainless steel. The effects of hardening and severe roughness (grinding) have also been investigated. In a first set of tests, the evolution of the surface damage induced by the different LCF pre-cycling was characterized. This has permitted to identify mechanisms and kinetics of damage in the plastic domain for different surface conditions. Then, pre-damaged samples were tested in the High Cycle Fatigue domain in order to establish the fatigue limits associated with each level of pre-damage. Results evidence that, in the case of polished samples, an important number of cycles is required to initiate surface cracks ant then to affect the fatigue limit of the material but, in the case of ground samples, a few number of cycles is sufficient to initiate cracks and to critically decrease the fatigue limit. The fatigue limit of pre-damaged samples can be estimated using the stress intensity factor threshold. Moreover, this detrimental effect of severe surface conditions is enhanced when fatigue tests are performed under a positive mean stress (author)

  17. Characterization of welding of AISI 304l stainless steel similar to the core encircling of a BWR reactor; Caracterizacion de soldaduras de acero inoxidable AISI 304L similares a las de la envolvente del nucleo de un reactor BWR

    Energy Technology Data Exchange (ETDEWEB)

    Gachuz M, M.E.; Palacios P, F.; Robles P, E.F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    Plates of austenitic stainless steel AISI 304l of 0.0381 m thickness were welded by means of the SMAW process according to that recommended in the Section 9 of the ASME Code, so that it was reproduced the welding process used to assemble the encircling of the core of a BWR/5 reactor similar to that of the Laguna Verde Nucleo electric plant, there being generated the necessary documentation for the qualification of the one welding procedure and of the welder. They were characterized so much the one base metal, as the welding cord by means of metallographic techniques, scanning electron microscopy, X-ray diffraction, mechanical essays and fracture mechanics. From the obtained results it highlights the presence of an area affected by the heat of up to 1.5 mm of wide and a value of fracture tenacity (J{sub IC}) to ambient temperature for the base metal of 528 KJ/m{sup 2}, which is diminished by the presence of the welding and by the increment in the temperature of the one essay. Also it was carried out an fractographic analysis of the fracture zone generated by the tenacity essays, what evidence a ductile fracture. The experimental values of resistance and tenacity are important for the study of the structural integrity of the encircling one of the core. (Author)

  18. Effect of Isothermal Hold on the Microstructural Evolution of the Stainless Steel 304L/Zircaloy-4 Interface

    Science.gov (United States)

    Lebaili, A.; Taouinet, M.; Nibou, D.; Lebaili, S.; Hodaj, F.

    2017-07-01

    The transition from solid-state bonding of the stainless steel 304L/Zircaloy-4 diffusion couple to a partial liquid-phase bonding is important for the bonding process at temperatures ranging from 950 to 1050 °C. In this study, the temperature at which a melting process occurs at the interface after 45 min of isothermal holdings is determined experimentally. This melting process leads to a drastic change in the thickness of the reaction products zone (RPZ) as well as on its microstructure. Diffusion couples were characterized by SEM-EDS, and quantitative chemical analyses of different phases are performed by EPMA. The RPZ consists of three layers: the (α-Fe-Cr) phase layer and two layers consisting of Zr(Fe,Cr)2 (ɛ), Zr2(Fe,Ni) and (α-Zr) phases. The thickness of these layers strongly depends on the holding temperature. The analysis allowed the description of the physicochemical phenomena occurring during isothermal holding as well as during cooling. The solidification paths are determined at 1000, 1020 and 1050 °C. Hardness tests are performed on the bonded samples in order to qualify the mechanical properties of different phases of the RPZ. This study leads to a better understanding of the complex phenomena intervening in the joining process which is very useful for applications in industrial scale.

  19. Physisorption of ammonia on AISI 304L stainless steel at different surface temperature under high vacuum conditions

    Directory of Open Access Journals (Sweden)

    A. de Castro

    2016-12-01

    Full Text Available The physisorption of ammonia molecules (sticking on the walls of a stainless steel pipe (AISI 304L has been studied at different wall temperatures (323-473K. The total amount of ammonia that is retained on the walls, once equilibrium is reached, has been measured by differentially-pumped mass spectrometry in gas exposure laboratory experiments. The results show ammonia retentions in the range of μg/cm2 resulting in a multilayer adsorption with lower amounts of stuck ammonia at higher temperatures of the stainless steel surface. The sticking coefficient follows an exponential decay evolution with time. The activation energy of the process has been estimated by an Arrhenius fit, assuming that the characteristic time for this decay is inversely proportional to the kinetic adsorption constant. A value of 0.15eV per ammonia molecule has been obtained, being in agreement with nominal values for the physisorption of small molecules or atoms (CO, N2, Ar… that can be found in the specialized literature. The implication of these results in the possible extrapolation to the ITER vacuum system under nitrogen seeded plasma operation is also addressed.

  20. Martensite phase reversion-induced nano/ ultrafine grained AISI 304L stainless steel with magnificent mechanical properties

    Directory of Open Access Journals (Sweden)

    Mohammad Shirdel

    2015-06-01

    Full Text Available Austenitic stainless steels are extensively used in various applications requiring good corrosion resistance and formability. In the current study, the formation of nano/ ultrafine grained austenitic microstructure in a microalloyed AISI 304L stainless steel was investigated by the advanced thermomechanical process of reversion of strain-induced martensite. For this purpose, samples were subjected to heavy cold rolling to produce a nearly complete martensitic structure. Subsequently, a wide range of annealing temperatures (600 to 800°C and times (1 to 240 min were employed to assess the reversion behavior and to find the best annealing condition for the production of the nano/ultrafine grained austenitic microstructure. Microstructural characterizations have been performed using X-ray diffraction (XRD, scanning electron microscopy (SEM, and magnetic measurement, whereas the mechanical properties were assessed by tensile and hardness tests. After thermomechanical treatment, a very fine austenitic structure was obtained, which was composed of nano sized grains of ~ 85 nm in an ultrafine grained matrix with an average grain size of 480 nm. This microstructure exhibited superior mechanical properties: high tensile strength of about 1280 MPa with a desirable elongation of about 41%, which can pave the way for the application of these sheets in the automotive industry.

  1. Evaluation of stress corrosion cracking of irradiated 304L stainless steel in PWR environment using heavy ion irradiation

    Science.gov (United States)

    Gupta, J.; Hure, J.; Tanguy, B.; Laffont, L.; Lafont, M.-C.; Andrieu, E.

    2016-08-01

    IASCC has been a major concern regarding the structural and functional integrity of core internals of PWR's, especially baffle-to-former bolts. Despite numerous studies over the past few decades, additional evaluation of the parameters influencing IASCC is still needed for an accurate understanding and modeling of this phenomenon. In this study, Fe irradiation at 450 °C was used to study the cracking susceptibility of 304 L austenitic stainless steel. After 10 MeV Fe irradiation to 5 dpa, irradiation-induced damage in the microstructure was characterized and quantified along with nano-hardness measurements. After 4% plastic strain in a PWR environment, quantitative information on the degree of strain localization, as determined by slip-line spacing, was obtained using SEM. Fe-irradiated material strained to 4% in a PWR environment exhibited crack initiation sites that were similar to those that occur in neutron- and proton-irradiated materials, which suggests that Fe irradiation may be a representative means for studying IASCC susceptibility. Fe-irradiated material subjected to 4% plastic strain in an inert argon environment did not exhibit any cracking, which suggests that localized deformation is not in itself sufficient for initiating cracking for the irradiation conditions used in this study.

  2. In Situ Neutron Diffraction Study of the Influence of Microstructure on the Mechanical Response of Additively Manufactured 304L Stainless Steel

    Science.gov (United States)

    Brown, D. W.; Adams, D. P.; Balogh, L.; Carpenter, J. S.; Clausen, B.; King, G.; Reedlunn, B.; Palmer, T. A.; Maguire, M. C.; Vogel, S. C.

    2017-12-01

    In situ neutron diffraction measurements were completed during tensile and compressive deformation of stainless steel 304L additively manufactured (AM) using a high power directed energy deposition process. Traditionally produced wrought 304L material was also studied for comparison. The AM material exhibited roughly 200 MPa higher flow stress relative to the wrought material. Crystallite size, crystallographic texture, dislocation density, and lattice strains were all characterized to understand the differences in the macroscopic mechanical behavior. The AM material's initial dislocation density was about 10 times that of the wrought material, and the flow strength of both materials obeyed the Taylor equation, indicating that the AM material's increased yield strength was primarily due to greater dislocation density. Also, a 50 MPa flow strength tension/compression asymmetry was observed in the AM material, and several potential causes were examined.

  3. In Situ Neutron Diffraction Study of the Influence of Microstructure on the Mechanical Response of Additively Manufactured 304L Stainless Steel

    Science.gov (United States)

    Brown, D. W.; Adams, D. P.; Balogh, L.; Carpenter, J. S.; Clausen, B.; King, G.; Reedlunn, B.; Palmer, T. A.; Maguire, M. C.; Vogel, S. C.

    2017-10-01

    In situ neutron diffraction measurements were completed during tensile and compressive deformation of stainless steel 304L additively manufactured (AM) using a high power directed energy deposition process. Traditionally produced wrought 304L material was also studied for comparison. The AM material exhibited roughly 200 MPa higher flow stress relative to the wrought material. Crystallite size, crystallographic texture, dislocation density, and lattice strains were all characterized to understand the differences in the macroscopic mechanical behavior. The AM material's initial dislocation density was about 10 times that of the wrought material, and the flow strength of both materials obeyed the Taylor equation, indicating that the AM material's increased yield strength was primarily due to greater dislocation density. Also, a 50 MPa flow strength tension/compression asymmetry was observed in the AM material, and several potential causes were examined.

  4. Numerical Simulation and Artificial Neural Network Modeling for Predicting Welding-Induced Distortion in Butt-Welded 304L Stainless Steel Plates

    Science.gov (United States)

    Narayanareddy, V. V.; Chandrasekhar, N.; Vasudevan, M.; Muthukumaran, S.; Vasantharaja, P.

    2016-02-01

    In the present study, artificial neural network modeling has been employed for predicting welding-induced angular distortions in autogenous butt-welded 304L stainless steel plates. The input data for the neural network have been obtained from a series of three-dimensional finite element simulations of TIG welding for a wide range of plate dimensions. Thermo-elasto-plastic analysis was carried out for 304L stainless steel plates during autogenous TIG welding employing double ellipsoidal heat source. The simulated thermal cycles were validated by measuring thermal cycles using thermocouples at predetermined positions, and the simulated distortion values were validated by measuring distortion using vertical height gauge for three cases. There was a good agreement between the model predictions and the measured values. Then, a multilayer feed-forward back propagation neural network has been developed using the numerically simulated data. Artificial neural network model developed in the present study predicted the angular distortion accurately.

  5. The microstructure and fracture behavior of the dissimilar alloy 690-SUS 304L joint with various Nb addition

    Science.gov (United States)

    Lee, H. T.; Jeng, S. L.; Kuo, T. Y.

    2003-05-01

    This study investigates the microstructure and fracture behavior of dissimilar weldments of alloy 690 and SUS 304L for various additions of niobium (0.1, 1.03, 2.49, and 3.35 wt pct) in the flux. With identical parameters and procedures, weldments were butt welded by the shielding metal arc welding (SMAW) process using three layers, with each layer being deposited in a single pass. The results indicate that the microstructure of the fusion zone was primarily dendritic and that the contents of Ni, Cr, and Fe within this zone remain relatively constant and resemble alloy 690. With Nb addition, it is noted that the microstructure changes from a cellular to columnar dendrite and equiaxed dendrite. Meanwhile, the dendrite arm spacing reduces and the secondary arms grow longer. Moreover, the composition of the interdendritic phase, whose precipitate volume percentage increases from 5 to 25 pct, changes from Al-Ti-O to Nb rich. The spread of the interdendritic phase is less in the root bead than in the cap bead due to the greater influence of base metal dilution in this region. Mechanical tests indicate that Nb addition increases the average hardness of the weldment and reduces its elongation prior to rupture. However, the tensile strength is essentially unchanged by Nb addition. It is found that the average hardness of the root bead is generally lower than the cap bead, and that the tensile specimens all rupture in the fusion zone, with the fracture surfaces exhibiting ductile features. It is noted that the cap bead tends to rupture interdendritically with increasing Nb addition. Finally, fractography shows that the dimples in the root become larger and shallower with Nb addition and are rich with an interdendritic phase.

  6. Structure and related corrosion behaviour in 1M H{sub 2}SO{sub 4} of b.c.c. 304L films prepared by ion beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Idiri, M.; Boubeker, B. [Faculte des Science, Casablanca (Morocco). Lab. de Controle et d' Analyse des Materiaux; Sabot, R. [Laboratoire d' Etudes des Materiaux en Milieux Agressifs, Universite de La Rochelle, Faculte des Sciences, Avenue Marillac, 17042, La Rochelle (France); Goudeau, P. [Laboratoire de Metallurgie Physique, Universite de Poitiers, UMR 6630 du CNRS, Universite de Poitiers, SP2MI, Bd 3, Teleport 2, B.P; 179, 86960, Futuroscope (France); Dinhut, J.-F.; Grosseau-Poussard, J.-L. [Laboratoire d' Etudes des Materiaux en Milieux Agressifs, Universite de La Rochelle, Faculte des Sciences, Avenue Marillac, 17042, La Rochelle (France)

    1999-12-15

    The corrosion behaviour in a non-deaered 1M H{sub 2}SO{sub 4} solution of 304L stainless steel (SS) in bulk and thin film state was investigated. In the first step, we elaborated based cubic-centred 304L stainless steel thin films onto Si and f.c.c. 304L SS bulk substrates by using a sputter deposition method. Then, the structure and residual macrostress state of the films were studied by X-ray diffraction. It was found that films are in a highly compressive state ({approx}3 GPa). Finally, corrosion tests revealed an improvement in corrosion resistance of the films with respect to the bulk 304L stainless steel. (orig.)

  7. RESULTS OF EXPERIMENT TO DETERMINE CORROSION RATES FOR 304L IN HB-LINE DISSOLVER VESSEL VENTILATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J; Kathryn Counts, K

    2008-02-22

    Radioactive material being processed as part of the DE3013 program for HB-Line will result in the presence of chlorides, and in some cases fluorides, in the dissolver. Material Science and Technology developed an experimental plan to evaluate the impact of chloride on corrosion of the dissolver vessel ventilation system. The plan set test variables from the proposed operating parameters, previous test results, and a desired maximum chloride concentration for processing. The test variables included concentrations of nitric acid, fluorides and chlorides, and the presence of a welded and stressed metal coupon. Table 1 contains expected general corrosion rates in the HB-Line vessel vent system from dissolution of 3013 contents of varying nitric acid and chloride content. These general corrosion rates were measured upstream of the condenser in the experiment's offgas system near the entrance to the dissolver. However, they could apply elsewhere in the offgas system, depending on factors not simulated in the testing, including offgas system temperatures and airflow. Localized corrosion was significant in Tests One, Two, and Three. This corrosion is significant because it will probably be the first mode of penetration of the 304L steel in several places in the system. See Table 2. For Tests One and Three, the penetration rate of localized corrosion was much higher than that for general corrosion. It was approximately four times higher in Test One and at least 45 times higher in Test Three, penetrating an entire coupon thickness of 54 mils in 186 hours or less. There was no significant difference in corrosion between welded areas and un-welded areas on coupons. There was also no significant attack on stressed portions of coupons. It is probable that the lack of corrosion was because the stressed areas were facing downwards and offered no place for condensation or deposits to form. Had deposits formed, pitting may have occurred and led to stress corrosion cracking. The

  8. Influence of Size on the Microstructure and Mechanical Properties of an AISI 304L Stainless Steel—A Comparison between Bulk and Fibers

    Directory of Open Access Journals (Sweden)

    Francisco J. Baldenebro-Lopez

    2015-01-01

    Full Text Available In this work, the mechanical properties and microstructural features of an AISI 304L stainless steel in two presentations, bulk and fibers, were systematically studied in order to establish the relationship among microstructure, mechanical properties, manufacturing process and effect on sample size. The microstructure was analyzed by XRD, SEM and TEM techniques. The strength, Young’s modulus and elongation of the samples were determined by tensile tests, while the hardness was measured by Vickers microhardness and nanoindentation tests. The materials have been observed to possess different mechanical and microstructural properties, which are compared and discussed.

  9. Experimental research on the effect of the ball burnishing process, using new kinematical scheme on hardness and phase composition of surface layer of AISI 304L stainless steel

    Directory of Open Access Journals (Sweden)

    Dimitrov Diyan M.

    2017-01-01

    Full Text Available In this paper, experimental results about hardness and phase composition of surface layer of AISI 304L SS, machined by using ball burnishing process, conducted under a new kinematic scheme, are presented. The effect of different combinations of the process regime parameters on the amount of strain induced martensitic phase, is discussed. The amounts of austenitic and strain induced martensitic phases are identified by x-ray diffractometer. Micro hardness along the depth of the hardened layer is measured. Conclusions about the influence of the ball burnishing process on strain induced martensitic phase are given.

  10. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Hitendra K., E-mail: hkmalik@physics.iitd.ac.in [Department of Physics, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Singh, Omveer [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Dahiya, Raj P. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Deenbandhu Chhotu Ram University of Science and Technology, Murthal–131039 (India)

    2015-08-28

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N{sub 2} and 30% H{sub 2} gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples.

  11. Solar Thermal AIR Collector Based on New Type Selective Coating

    National Research Council Canada - National Science Library

    Musiy, R.Y; Midyana, G.G; Makitra, R.G; Vasyutin, J.M; Khovanets, G.I; Zaborowskiy, A.B

    2014-01-01

    Based on the best for optical performance and selective coating solar thermal air collector, which operates by solar power on the principle of simultaneous ventilation and heating facilities, is designed...

  12. Transient liquid-phase bonding using coated metal powders

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, W.D.; Eagar, T.W. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering

    1997-04-01

    Powder particles coated with a small amount of melting point depressant (MPD) reveal different sintering behavior in comparison to an uncoated powder mixture of the same composition. Interlayers consisting of the coated powder particles were used in the transient liquid-phase (TLP) bonding process. The coating material and the thickness of the deposit are important parameters that influence shrinkage. The amount of MPD was controlled such that the volume fraction of the liquid was very small but existed at all contacts, thus improving densification of the interlayer. Ni-20Cr and 304L stainless steel powders coated with Ni-10P were applied to join 304 stainless steels. Fully dense joints with mechanical properties comparable to those of the base metals were obtained with Ni-20Cr powder interlayers, whereas joints with 304L stainless steel powder interlayers showed inferior mechanical properties due to residual porosity in the joints.

  13. Thermal stability and adhesion of low-emissivity electroplated Au coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Jorenby, Jeff W.; Hachman, John T., Jr.; Yang, Nancy Y. C.; Chames, Jeffrey M.; Clift, W. Miles

    2010-12-01

    We are developing a low-emissivity thermal management coating system to minimize radiative heat losses under a high-vacuum environment. Good adhesion, low outgassing, and good thermal stability of the coating material are essential elements for a long-life, reliable thermal management device. The system of electroplated Au coating on the adhesion-enhancing Wood's Ni strike and 304L substrate was selected due to its low emissivity and low surface chemical reactivity. The physical and chemical properties, interface bonding, thermal aging, and compatibility of the above Au/Ni/304L system were examined extensively. The study shows that the as-plated electroplated Au and Ni samples contain submicron columnar grains, stringers of nanopores, and/or H{sub 2} gas bubbles, as expected. The grain structure of Au and Ni are thermally stable up to 250 C for 63 days. The interface bonding is strong, which can be attributed to good mechanical locking among the Au, the 304L, and the porous Ni strike. However, thermal instability of the nanopore structure (i.e., pore coalescence and coarsening due to vacancy and/or entrapped gaseous phase diffusion) and Ni diffusion were observed. In addition, the study also found that prebaking 304L in the furnace at {ge} 1 x 10{sup -4} Torr promotes surface Cr-oxides on the 304L surface, which reduces the effectiveness of the intended H-removal. The extent of the pore coalescence and coarsening and their effect on the long-term system integrity and outgassing are yet to be understood. Mitigating system outgassing and improving Au adhesion require a further understanding of the process-structure-system performance relationships within the electroplated Au/Ni/304L system.

  14. Solar Thermal AIR Collector Based on New Type Selective Coating

    Directory of Open Access Journals (Sweden)

    Musiy, R.Y.

    2014-01-01

    Full Text Available Based on the best for optical performance and selective coating solar thermal air collector, which operates by solar power on the principle of simultaneous ventilation and heating facilities, is designed. It can be used for vacation homes, museums, wooden churches, warehouses, garages, houses, greenhouses etc.

  15. Characterization of gas tunnel type plasma sprayed hydroxyapatite-nanostructure titania composite coatings

    Science.gov (United States)

    Yugeswaran, S.; Kobayashi, A.; Ucisik, A. Hikmet; Subramanian, B.

    2015-08-01

    Hydroxyapatite (HA) can be coated onto metal implants as a ceramic biocompatible coating to bridge the growth between implants and human tissue. Meanwhile many efforts have been made to improve the mechanical properties of the HA coatings without affecting its bioactivity. In the present study, nanostructure titania (TiO2) was mixed with HA powder and HA-nanostructure TiO2 composite coatings were produced by gas tunnel type plasma spraying torch under optimized spraying conditions. For this purpose, composition of 10 wt% TiO2 + 90 wt% HA, 20 wt% TiO2 + 80 wt% HA and 30 wt% TiO2 + 70 wt% HA were selected as the feedstock materials. The phase, microstructure and mechanical properties of the coatings were characterized. The obtained results validated that the increase in weight percentage of nanostructure TiO2 in HA coating significantly increased the microhardness, adhesive strength and wear resistance of the coatings. Analysis of the in vitro bioactivity and cytocompatibility of the coatings were done using conventional simulated body fluid (c-SBF) solution and cultured green fluorescent protein (GFP) labeled marrow stromal cells (MSCs) respectively. The bioactivity results revealed that the composite coating has bio-active surface with good cytocompatibility.

  16. A new type of coating to chase the clouds away

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    The electron cloud problem needs to be addressed with innovative solutions, particularly in view of the rapidly approaching HL-LHC upgrade. CERN’s Vacuum, Surfaces and Coatings group has greatly improved its amorphous carbon coating technique, which is an alternative to the scrubbing process used so far. This technique is now fully mature and is being used for the vacuum chambers of the SPS magnets and the delicate beam screens of the LHC’s quadrupole triplets.   The violet light is produced by the argon plasma used when sputtering the amorphous carbon. The beam screen is coated in this case using the magnetic field of the quadrupole itself. (Image: Pedro Costa Pinto) We know that conditioning (or “scrubbing”) the beam pipe reduces the avalanche-like creation of secondary electrons from the tube’s walls, thus preventing the formation of unwanted electron clouds. But it has also been observed that scrubbing natur...

  17. Analysis of different coating thickness on new type of planar interdigital sensors for endotoxin detection

    KAUST Repository

    Syaifudin, A. R Mohd

    2013-05-01

    New types of planar interdigital sensors have been fabricated on Silicon/Silicon Dioxide (Si/SiO2) wafers. The sensors were coated with pre-cursor silica functionalized with APTES (3-aminopropyltrietoxysilane) at different thicknesses. All sensors were then immobilized with Polymyxin, B (PmB). PmB is an antimicrobial peptide produced by the Gram-positive bacterium-Bacillus, has been immobilized on the coated sensors because of its specific binding properties to endotoxin. Studies were conducted to analyze the effect of different thicknesses of coatings on the sensitivity and selectivity of the sensors. It was observed sensors coated with 3 layers of coating has better sensitivity and selectivity to the target molecules (endotoxin) compared to sensors with 5 layers of coating. The repeatability and stability of the coated sensors were tested by multiple standard endotoxin measurement and it was observed that the sensors give a good reproducibility and stability up to six continuous measurements before the coating degrades. © 2013 IEEE.

  18. Machining and Surface Characteristics of AISI 304L After Electric Discharge Machining for Copper and Graphite Electrodes in Different Dielectric Liquids

    Directory of Open Access Journals (Sweden)

    S. Anjum

    2017-08-01

    Full Text Available In Electric Discharge Machining (EDM, the thermal energy used for material erosion depends on the intensity of electric sparks, the thermal conductivities of electrode material and the dielectric liquid. In this paper, the effect of EDM on AISI 304L steel is studied using copper and graphite electrodes and distilled water and kerosene oil as dielectric liquids. Material Removal Rates (MRR, Tool Wear Rates (TWR and surface conditions are calculated for four different combinations with the two electrode materials and the two dielectric liquids. These investigations are carried out at different pulse currents. Machined surfaces are evaluated by morphological studies, energy dispersive spectrographs (EDS and white layer thickness using Scanning Electron Microscopy (SEM. It is found that a transfer of carbon takes place from the kerosene oil and the graphite electrodes into the machined surface which alters the metallurgical characteristics, depending on the electrical and thermal conductivities of the electrode material and the dielectric liquid.

  19. Simulation and experimental comparison of the thermo-mechanical history and 3D microstructure evolution of 304L stainless steel tubes manufactured using LENS

    Science.gov (United States)

    Johnson, Kyle L.; Rodgers, Theron M.; Underwood, Olivia D.; Madison, Jonathan D.; Ford, Kurtis R.; Whetten, Shaun R.; Dagel, Daryl J.; Bishop, Joseph E.

    2017-12-01

    Additive manufacturing enables the production of previously unachievable designs in conjunction with time and cost savings. However, spatially and temporally fluctuating thermal histories can lead to residual stress states and microstructural variations that challenge conventional assumptions used to predict part performance. Numerical simulations offer a viable way to explore the root causes of these characteristics, and can provide insight into methods of controlling them. Here, the thermal history of a 304L stainless steel cylinder produced using the Laser Engineered Net Shape process is simulated using finite element analysis (FEA). The resultant thermal history is coupled to both a solid mechanics FEA simulation to predict residual stress and a kinetic Monte Carlo model to predict the three-dimensional grain structure evolution. Experimental EBSD measurements of grain structure and in-process infrared thermal data are compared to the predictions.

  20. Optimization Of Pulsed Current Parameters To Minimize Pitting Corrosion İn Pulsed Current Micro Plasma Arc Welded Aısı 304l Sheets Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Kondapalli Siva Prasad

    2013-06-01

    Full Text Available Austenitic stainless steel sheets have gathered wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. In case of single pass welding of thinner sections of this alloy, Pulsed Current Micro Plasma Arc Welding (PCMPAW was found beneficial due to its advantages over the conventional continuous current process. This paper highlights the development of empirical mathematical equations using multiple regression analysis, correlating various process parameters to pitting corrosion rates in PCMPAW of AISI 304L sheets in 1 Normal HCl. The experiments were conducted based on a five factor, five level central composite rotatable design matrix. A Genetic Algorithm (GA was developed to optimize the process parameters for minimizing the pitting corrosion rates.

  1. Coating-type three-dimensional acetate-driven microbial fuel cells.

    Science.gov (United States)

    Yu, Jin; Tang, Yulan

    2015-08-01

    This study uses sodium acetate as fuel to construct bioelectricity in coating-type three-dimensional microbial fuel cells anode. The coating-type three-dimensional anode was constructed using iron net as structural support, adhering a layer of carbon felt as primary coating and using carbon powder and 30% PTFE solution mixture as coating. The efficiency of electricity production and wastewater treatment were analyzed for the three-dimensional acetate-fed (C2H3NaO2) microbial fuel cells with the various ratio of the coating mixture. The results showed that the efficiency of electricity production was significantly improved when using the homemade coating-type microbial fuel cells anode compared with the one without coating on the iron net, which the apparent internal resistance was decreased by 59.4% and the maximum power density was increased by 1.5 times. It was found the electricity production was greatly influenced by the ratio of the carbon powder and PTFE in the coating. The electricity production was the highest with apparent internal resistance of 190 Ω, and maximum power density of 5189.4 mW m(-3) when 750 mg of carbon powder and 10 ml of PTFE (i.e., ratio 75:1) was used in the coating. With the efficiency of electricity production, wide distribution and low cost of the raw materials, the homemade acetate-fed microbial fuel cells provides a valuable reference to the development of the composition microbial fuel cell anode production. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Corrosion Behavior of Detonation Gun Sprayed Fe-Al Type Intermetallic Coating

    Directory of Open Access Journals (Sweden)

    Cezary Senderowski

    2015-03-01

    Full Text Available The detonation gun sprayed Fe-Al type coatings as an alternative for austenitic valve steel, were investigated using two different methods of testing corrosion resistance. High temperature, 10-hour isothermal oxidation experiments at 550, 750, 950 and 1100 °C show differences in the oxidation behavior of Fe-Al type coatings under air atmosphere. The oxide layer ensures satisfying oxidation resistance, even at 950 and 1100 °C. Hematite, α-Al2O3 and metastable alumina phases were noticed on the coatings top surface, which preserves its initial thickness providing protection to the underlying substrate. In general, only negligible changes of the phase composition of the coatings were noticed with simultaneous strengthening controlled in the micro-hardness measurements, even after 10-hours of heating at 1100 °C. On the other hand, the electrochemical corrosion tests, which were carried out in 200 ppm Cl− (NaCl and pH ~4 (H2SO4 solution to simulate the acid-rain environment, reveal higher values of the breakdown potential for D-gun sprayed Fe-Al type coatings than the ones for the bulk Fe-Al type alloy and Cr21Mn9Ni4 austenitic valve steel. This enables these materials to be used in structural and multifunctional applications in aggressive environments, including acidic ones.

  3. Thermal properties and flame retardancy of an ether-type UV-cured polyurethane coating

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available A new UV-reactive monomer piperazine-N,N′-bis(acryloxyethylaryl-phosphoramidate (N-PBAAP containing phosphorus and nitrogen was synthesized and used as flame retardant for an ether-type UV-cured polyurethane acrylate (PUA coating. The thermal properties of the PUA films were investigated by thermogravimetric analysis (TGA in air and nitrogen atmosphere. The TGA results showed that the incorporation of N-PBAAP can obviously enhance the char residue of the PUA coatings. From the TGA and real time Fourier transformed infrared spectroscopy (RT-FTIR results, different degradation behaviors were observed in the PUA coatings with different N-PBAAP content. The combustibility of the PUA coatings was evaluated by microscale combustion calorimeter (MCC. The MCC results revealed that the addition of NPBAAP in the coatings can significantly reduce the peak Heat Release Rate (pHRR, Heat Release Capacity (HRC and the Total Heat Release (THR of the samples. Furthermore, dynamical mechanical thermal analysis (DMA was employed to examine the viscoelastic properties of the PUA films. It was found that the incorporation of N-PBAAP in the formulation can bring in more functional groups to the coatings, which results in an increase of the glass transition temperature (Tg and cross linking density (XLD of the films.

  4. Superhydrophobic aluminium-based surfaces: Wetting and wear properties of different CVD-generated coating types

    Science.gov (United States)

    Thieme, M.; Streller, F.; Simon, F.; Frenzel, R.; White, A. J.

    2013-10-01

    In view of generating superhydrophobic aluminium-based surfaces, this work presents further results for the combination of anodic oxidation as the primary pretreatment method and chemical vapour deposition (CVD) variants for chemical modification producing coatings of 250-1000 nm thickness. In detail, CVD involved the utilisation of i - hexafluoropropylene oxide as precursor within the hot filament CVD process for the deposition of poly(tetrafluoroethylene) coatings at alternative conditions (PTFE-AC) and ii - 1,3,5-trivinyltrimethylcyclotrisiloxane for the deposition of polysiloxane coatings (PSi) by initiated CVD. The substrate material was Al Mg1 subjected to usual or intensified sulphuric acid anodisation pretreatments (SAAu, SAAi, respectively) affording various degrees of surface micro-roughness (SAAu standardised artificial weathering and/or mild wear testing. Superhydrophobicity (SH) was observed with the system SAAi + PTFE-AC similarly to former findings with the standard hot filament CVD PTFE coating variant (SAAi + PTFE-SC). The results indicated that the specific coating morphology made an important contribution to the water-repellency, because even some of the SAAu-based samples tended to reveal SH. Subjecting samples to weathering treatment resulted in a general worsening of the wetting behaviour, primarily limited to the receding contact angles. These tendencies were correlated with the chemical composition of the sample surfaces as analysed by X-ray photoelectron spectroscopy. The wear tests showed, as evaluated by scanning electron microscopy and contact angle measurement, that the PTFE coatings were relatively sensitive to friction. This was connected with a dramatic deterioration of the water-repelling properties. PSi-coated surfaces generally showed rather poor water-repellency, but this coating type was surprisingly resistant towards the applied friction test. From these findings it may be concluded that the combination of hydrophobic fluorine

  5. Effect of internal heating during hot compression testing on the stress-strain behavior and hot working characteristics of Alloy 304L

    Energy Technology Data Exchange (ETDEWEB)

    Mataya, M.C.; Sackschewsky, V.E.

    1993-05-01

    Temperature change from conversion of deformation to internal heat, and its effect on stress-strain behavior of alloy 304L was investigated by initially isothermal (temperature of specimen, compression dies, environment equilibrated at initiation of test) uniaxial compression. Strain rate was varied 0.01 s{sup {minus}1} to 1 s{sup {minus}1} (thermal state of specimen varied from nearly isothermal to nearly adiabatic). Specimens were deformed at 750 to 1150 to a strain of 1. Change in temperature with strain was calculated via finite element analysis from measured stress-strain data and predictions were confirmed with thermocouples to verify the model. Temperature increased nearly linearly at the highest strain rate, consistent with temperature rise being a linear function of strain (adiabatic). As strain rate was lowered, heat transfer from superheated specimen to cooler dies caused sample temperature to increase and then decrease with strain as the sample thinned and specimen-die contact area increased. As-measured stress was corrected. Resulting isothermal flow curves were compared to predictions of a simplified method suggested by Thomas and Shrinivasan and differences are discussed. Strain rate sensitivity, activation energy for deformation, and flow curve peak associated with onset of dynamic recrystallization were determined from both as-measured and isothermal stress-strain data and found to vary widely. The impact of utilizing as-measured stress-strain data, not corrected for internal heating, on results of a number of published investigations is discussed.

  6. Effect of hydrogen charging on fracture toughness obtained by small specimen of SUS304L : Study on low temperature materials used in WE-NET 19

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, T.; Saito, M.; Yuri, T. [National Institute for Materials Science (Japan). Materials Information Technology Station; Hirayama, Y. [Mitsubishi Heavy Industries Ltd. (Japan); Eguchi, H. [Ishikawajima-Harima Heavy Industries Co. Ltd. (Japan)

    2002-07-01

    The ductility of austenitic stainless steels even at cryogenic temperatures and a hydrogen environment make it a widely used material in cryogenic applications. The evaluation of mechanical properties of structural materials including weld metals at low temperatures is important, as fracture toughness of cryogenic materials is required for the design of large scale facilities such as clean energy to transport and store liquid hydrogen. The authors used a new testing procedure of J-evaluation on tensile test (JETT) to evaluate local fracture toughness of top, middle, bottom, and heat-affected zone of welds of SUS304L. The tests revealed that a decrease of 9 parts per million hydrogen-charging occurred in fracture toughness in 5 per cent and 10 per cent delta-ferrite welds, and that toughness decreased by only 4 parts per million hydrogen-charging in 10 per cent welds. The authors concluded that less amount of delta-ferrite weld has less influence of hydrogen embrittlement and a critical amount of hydrogen-charging. 7 refs., 1 tab., 5 figs.

  7. Novel Alkyd-Type Coating Resins Produced Using Cationic Polymerization [PowerPoint

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, Bret; Kalita, Harjyoti; Alam, Samim; Jayasooriyamu, Anurad; Fernando, Shashi; Samanata, Satyabrata; Bahr, James; Selvakumar, Sermadurai; Sibi, Mukund; Vold, Jessica; Ulven, Chad

    2014-04-07

    Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(vinyl ether)s provide several advantages. These advantages include miler, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimmers, etc. The results of the studied showed that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerable as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.

  8. Microcapsule-Type Self-Healing Protective Coating for Cementitious Composites with Secondary Crack Preventing Ability

    Directory of Open Access Journals (Sweden)

    Dong-Min Kim

    2017-01-01

    Full Text Available A microcapsule-type self-healing protective coating with secondary crack preventing capability has been developed using a silanol-terminated polydimethylsiloxane (STP/dibutyltin dilaurate (DD healing agent. STP undergoes condensation reaction in the presence of DD to give a viscoelastic substance. STP- and DD-containing microcapsules were prepared by in-situ polymerization and interfacial polymerization methods, respectively. The microcapsules were characterized by Fourier-transform infrared (FT-IR spectroscopy, optical microscopy, and scanning electron microscopy (SEM. The microcapsules were integrated into commercial enamel paint or epoxy coating formulations, which were applied on silicon wafers, steel panels, and mortar specimens to make dual-capsule self-healing protective coatings. When the STP/DD-based coating was scratched, self-healing of the damaged region occurred, which was demonstrated by SEM, electrochemical test, and water permeability test. It was also confirmed that secondary crack did not occur in the healed region upon application of vigorous vibration to the self-healing coating.

  9. Optimization of Cvd Diamond Coating Type on Micro Drills in Pcb Machining

    Science.gov (United States)

    Lei, X. L.; He, Y.; Sun, F. H.

    2016-12-01

    The demand for better tools for machining printed circuit boards (PCBs) is increasing due to the extensive usage of these boards in digital electronic products. This paper is aimed at optimizing coating type on micro drills in order to extend their lifetime in PCB machining. First, the tribotests involving micro crystalline diamond (MCD), nano crystalline diamond (NCD) and bare tungsten carbide (WC-Co) against PCBs show that NCD-PCB tribopair exhibits the lowest friction coefficient (0.35) due to the unique nano structure and low surface roughness of NCD films. Thereafter, the dry machining performance of the MCD- and NCD-coated micro drills on PCBs is systematically studied, using diamond-like coating (DLC) and TiAlN-coated micro drills as comparison. The experiments show that the working lives of these micro drills can be ranked as: NCD>TiAlN>DLC>MCD>bare WC-Co. The superior cutting performance of NCD-coated micro drills in terms of the lowest flank wear growth rate, no tool degradation (e.g. chipping, tool tipping) appearance, the best hole quality as well as the lowest feed force may come from the excellent wear resistance, lower friction coefficient against PCB as well as the high adhesive strength on the underneath substrate of NCD films.

  10. Low-Temperature Self-Healing of a Microcapsule-Type Protective Coating

    Directory of Open Access Journals (Sweden)

    Dong-Min Kim

    2017-09-01

    Full Text Available Low-temperature self-healing capabilities are essential for self-healing materials exposed to cold environments. Although low-temperature self-healing concepts have been proposed, there has been no report of a microcapsule-type low-temperature self-healing system wherein the healing ability was demonstrated at low temperature. In this work, low-temperature self-healing of a microcapsule-type protective coating was demonstrated. This system employed silanol-terminated polydimethylsiloxane (STP as a healing agent and dibutyltin dilaurate (DD as a catalyst. STP underwent a condensation reaction at −20 °C in the presence of DD to give a viscoelastic product. The reaction behavior of STP and the viscoelasticity of the reaction product were investigated. STP and DD were separately microencapsulated by in situ polymerization and interfacial polymerization methods, respectively. The STP- and DD-loaded microcapsules were mixed into a commercial enamel paint, and the resulting formulation was applied to glass slides, steel panels, and mortars to prepare self-healing coatings. When the self-healing coatings were damaged at a low temperature (−20 °C, STP and DD were released from broken microcapsules and filled the damaged area. This process was effectively visualized using a fluorescent dye. The self-healing coatings were scratched and subjected to corrosion tests, electrochemical tests, and saline solution permeability tests. The temperature of the self-healing coatings was maintained at −20 °C before and after scratching and during the tests. We successfully demonstrated that the STP/DD-based coating system has good low-temperature self-healing capability.

  11. Low-Temperature Self-Healing of a Microcapsule-Type Protective Coating.

    Science.gov (United States)

    Kim, Dong-Min; Cho, Yu-Jin; Choi, Ju-Young; Kim, Beom-Jun; Jin, Seung-Won; Chung, Chan-Moon

    2017-09-14

    Low-temperature self-healing capabilities are essential for self-healing materials exposed to cold environments. Although low-temperature self-healing concepts have been proposed, there has been no report of a microcapsule-type low-temperature self-healing system wherein the healing ability was demonstrated at low temperature. In this work, low-temperature self-healing of a microcapsule-type protective coating was demonstrated. This system employed silanol-terminated polydimethylsiloxane (STP) as a healing agent and dibutyltin dilaurate (DD) as a catalyst. STP underwent a condensation reaction at -20 °C in the presence of DD to give a viscoelastic product. The reaction behavior of STP and the viscoelasticity of the reaction product were investigated. STP and DD were separately microencapsulated by in situ polymerization and interfacial polymerization methods, respectively. The STP- and DD-loaded microcapsules were mixed into a commercial enamel paint, and the resulting formulation was applied to glass slides, steel panels, and mortars to prepare self-healing coatings. When the self-healing coatings were damaged at a low temperature (-20 °C), STP and DD were released from broken microcapsules and filled the damaged area. This process was effectively visualized using a fluorescent dye. The self-healing coatings were scratched and subjected to corrosion tests, electrochemical tests, and saline solution permeability tests. The temperature of the self-healing coatings was maintained at -20 °C before and after scratching and during the tests. We successfully demonstrated that the STP/DD-based coating system has good low-temperature self-healing capability.

  12. Superhydrophobic aluminium-based surfaces: Wetting and wear properties of different CVD-generated coating types

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, M., E-mail: michael.thieme@tu-dresden.de [Technische Universität Dresden, Institute of Materials Science, 01062 Dresden (Germany); Streller, F., E-mail: streller@seas.upenn.edu [Technische Universität Dresden, Institute of Materials Science, 01062 Dresden (Germany); Simon, F., E-mail: frsimon@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden, Postfach 120 411, 01005 Dresden (Germany); Frenzel, R., E-mail: frenzelr@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden, Postfach 120 411, 01005 Dresden (Germany); White, A.J. [GVD Corporation, 45 Spinelli Place, Cambridge, MA 02138 (United States)

    2013-10-15

    In view of generating superhydrophobic aluminium-based surfaces, this work presents further results for the combination of anodic oxidation as the primary pretreatment method and chemical vapour deposition (CVD) variants for chemical modification producing coatings of 250–1000 nm thickness. In detail, CVD involved the utilisation of i – hexafluoropropylene oxide as precursor within the hot filament CVD process for the deposition of poly(tetrafluoroethylene) coatings at alternative conditions (PTFE-AC) and ii – 1,3,5-trivinyltrimethylcyclotrisiloxane for the deposition of polysiloxane coatings (PSi) by initiated CVD. The substrate material was Al Mg1 subjected to usual or intensified sulphuric acid anodisation pretreatments (SAAu, SAAi, respectively) affording various degrees of surface micro-roughness (SAAu < SAAi) to the oxidic layers. Performance characteristics were evaluated in the original as-coated states and after standardised artificial weathering and/or mild wear testing. Superhydrophobicity (SH) was observed with the system SAAi + PTFE-AC similarly to former findings with the standard hot filament CVD PTFE coating variant (SAAi + PTFE-SC). The results indicated that the specific coating morphology made an important contribution to the water-repellency, because even some of the SAAu-based samples tended to reveal SH. Subjecting samples to weathering treatment resulted in a general worsening of the wetting behaviour, primarily limited to the receding contact angles. These tendencies were correlated with the chemical composition of the sample surfaces as analysed by X-ray photoelectron spectroscopy. The wear tests showed, as evaluated by scanning electron microscopy and contact angle measurement, that the PTFE coatings were relatively sensitive to friction. This was connected with a dramatic deterioration of the water-repelling properties. PSi-coated surfaces generally showed rather poor water-repellency, but this coating type was surprisingly

  13. Different types of ferrite thin films as magnetic cantilever coating for magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Koblischka, M.R., E-mail: m.koblischka@mx.uni-saarland.d [Institute of Experimental Physics, Saarland University, P.O. Box 151150, D-66041 Saarbruecken (Germany); Kirsch, M.; Pfeifer, R.; Getlawi, S. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, D-66041 Saarbruecken (Germany); Rigato, F.; Fontcuberta, J. [Departamento di Magnetisme, CSIC, Bellaterra (Spain); Sulzbach, T. [Nanoworld services GmbH, Schottkystrasse 10, d-91058 Erlangen (Germany); Hartmann, U. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, D-66041 Saarbruecken (Germany)

    2010-05-15

    Different types of ferrites are employed in the form of thin films as magnetic coating on cantilevers for magnetic force microscopy (MFM) use. This is especially needed for cantilevers employed in high-frequency MFM (HF-MFM), where stray fields of hard disk recording heads are investigated. Our experiments show that we can operate HF-MFM successfully at carrier frequencies up 2 GHz using such ferrite-coated cantilevers. Thin films of two ferrites, NiZnFe{sub 2}O{sub 4} spinel ferrite and Co{sub 2} Z-type hexaferrite (Ba{sub 3}Co{sub 2}Fe{sub 24}O{sub 41}, BCFO) were prepared by RF sputtering. As a basis for these probes, we employ commercial micromachined silicon cantilevers. Additionally, films on Si (1 0 0) and Si (1 1 1)-oriented substrates with a thickness up to 100 nm were prepared for analysis purposes, enabling the optimization of the sputter process. For a high spatial resolution of MFM, however, thinner magnetic coatings are required. Therefore, the third type, c, was prepared by laser-ablation with a thickness of 30 nm, also directly onto the Si without additional buffer layer.

  14. Aluminum strand coating for increasing the interstrand contact resistance in Rutherford type superconducting cables

    CERN Document Server

    Scheuerlein, C; Verweij, A; Bonasia, A; Oberli, L; Taborelli, M; Richter, R

    2009-01-01

    The interstrand contact resistance (Rc) in Rutherford type cables for fast cycling superconducting magnets must be sufficiently high in order to limit eddy current losses. The required value for Rc depends on the cable and magnet geometries and on the foreseen cycling rate, but is typically of the order of one mW. Such values can be reached with a dedicated strand coating or with a resistive internal cable barrier. As a possible candidate Al strand coatings have been tested. For a Rutherford type inner conductor cable of the Large Hadron Collider (LHC) made of Al coated strands Rc values higher than 500 Omega are achieved. The native Al2O3 oxide layer formed at ambient temperature in air is sufficient to reach this high contact resistance. A 6 h-200 °C oxidation heat treatment in air with 100% relative humidity further increases Rc to values above 600 μOmega . Due to the high thermal and mechanical stability of Al2O3 only a relatively moderate Rc drop of about 40 % is obtained during a 190 °C heat treatmen...

  15. Thermal fatigue of a 304L austenitic stainless steel: simulation of the initiation and of the propagation of the short cracks in isothermal and aniso-thermal fatigue; Fatigue thermique d'un acier inoxydable austenitique 304L: simulation de l'amorcage et de la croissance des fissures courtes en fatigue isotherme et anisotherme

    Energy Technology Data Exchange (ETDEWEB)

    Haddar, N

    2003-04-01

    The elbow pipes of thermal plants cooling systems are submitted to thermal variations of short range and of variable frequency. These variations bound to temperature changes of the fluids present a risk of cracks and leakages. In order to solve this problem, EDF has started the 'CRECO RNE 808' plan: 'thermal fatigue of 304L austenitic stainless steels' to study experimentally on a volume part, the initiation and the beginning of the propagation of cracks in thermal fatigue on austenitic stainless steels. The aim of this study is more particularly to compare the behaviour and the damage of the material in mechanic-thermal fatigue (cycling in temperature and cycling in deformation) and in isothermal fatigue (the utmost conditions have been determined by EDF for the metal: Tmax = 165 degrees C and Tmin = 90 degrees C; the frequency of the thermal variations can reach a Hertz). A lot of experimental results are given. A model of lifetime is introduced and validated. (O.M.)

  16. Aluminum and Other Coatings for the Passivation of Tritium Storage Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Korinko, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-11-16

    Using a highly sensitive residual gas analyzer, the off-gassing of hydrogen, water, and hydrocarbons from surface-treated storage vessels containing deuterium was measured. The experimental storage vessels were compared to a low-off-gassing, electro-polished 304L canister. Alternative vessels were made out of aluminum, or were coatings on 304L steel. Coatings included powder pack aluminide, electro-plated aluminum, powder pack chromide, dense electro-plated chromium, copper plated, and copper plated with 25 and 50 percent nano-diamond. Vessels were loaded with low pressure deuterium to observe exchange with protium or hydrogen as observed with formation of HD and HDO. Off gas of D2O or possible CD4 was observed at mass 20. The main off-gas in all of the studies was H2. The studies indicated that coatings required significant post-coating treatment to reduce off-gas and enhance the permeation barrier from gases likely added during the coating process. Dense packed aluminum coatings needed heating to drive off water. Electro-plated aluminum, chromium and copper coatings appeared to trap hydrogen from the plating process. Nano-diamond appeared to enhance the exchange rate with hydrogen off gas, and its coating process trapped significant amounts of hydrogen. Aluminum caused more protium exchange than chromium-treated surfaces. Aluminum coatings released more water, but pure aluminum vessels released small amounts of hydrogen, little water, and generally performed well. Chromium coating had residual hydrogen that was difficult to totally outgas but otherwise gave low residuals for water and hydrocarbons. Our studies indicated that simple coating of as received 304L metal will not adequately block hydrogen. The base vessel needs to be carefully out-gassed before applying a coating, and the coating process will likely add additional hydrogen that must be removed. Initial simple bake-out and leak checks up to 350° C for a few hours was

  17. Experimental evaluation of coated carbide insert on alloy of steel materials during high speed turning process

    Directory of Open Access Journals (Sweden)

    S. A. Lawal

    2017-06-01

    Full Text Available The present study investigated the effect of coated carbide turning inserts on the surface roughness of AISI 304L austenitic stainless steel, AISI 316L austenitic stainless steel and AISI 1020 low carbon steel workpiece materials. The three steel grade materials were dry-turned using aluminium oxide (Al2O3 duratomic coated inserts at cutting speeds ranging from 1500 – 2000 rpm (229 – 314 m/min, feed rates of 0.25 – 0.75 mm/rev and depth of cut kept constant at 0.5 mm. Surface roughness values at different cutting conditions were measured and analysed. Chips formed at different cutting parameters were collected, classified according to ISO 3685 standards for chip classification and their surface morphology were analysed using optical microscopy. It was observed that feed rate had the greatest influence on surface roughness for the three workpiece materials. Surface finish deteriorated as feed rate increased. The chips formed were generally of the continuous type with built-up-edges.

  18. Visibility and oxidation stability of hybrid-type copper mesh electrodes with combined nickel-carbon nanotube coating

    Science.gov (United States)

    Kim, Bu-Jong; Hwang, Young-Jin; Park, Jin-Seok

    2017-04-01

    Hybrid-type transparent conductive electrodes (TCEs) were fabricated by coating copper (Cu) meshes with carbon nanotube (CNT) via electrophoretic deposition, and with nickel (Ni) via electroplating. For the fabricated electrodes, the effects of the coating with CNT and Ni on their transmittance and reflectance in the visible-light range, electrical sheet resistance, and chromatic parameters (e.g., redness and yellowness) were characterized. Also, an oxidation stability test was performed by exposing the electrodes to air for 20 d at 85 °C and 85% temperature and humidity conditions, respectively. It was discovered that the CNT coating considerably reduced the reflectance of the Cu meshes, and that the Ni coating effectively protected the Cu meshes against oxidation. Furthermore, after the coating with CNT, both the redness and yellowness of the Cu mesh regardless of the Ni coating approached almost zero, indicating a natural color. The experiment results confirmed that the hybrid-type Cu meshes with combined Ni-CNT coating improved characteristics in terms of reflectance, sheet resistance, oxidation stability, and color, superior to those of the primitive Cu mesh, and also simultaneously satisfied most of the requirements for TCEs.

  19. Does hydroxyapatite coating enhance ingrowth and improve longevity of a Zweymuller type stem? A double-blinded randomised RSA trial.

    Science.gov (United States)

    Hoornenborg, Daniel; Sierevelt, Inger N; Spuijbroek, Joost A; Cheung, John; van der Vis, Harm M; Beimers, Lijkele; Haverkamp, Daniel

    2017-09-11

    An ongoing discussion is whether using a hydroxyapatite coating enhances the ingrowth and longevity of a femoral stem in total hip arthroplasty. The best way to predict speed of ingrowth and long-term outcome is by evaluating micromotion by radiostereometric analysis. To study the effect of hydroxyapatite (HA) coating on the migration of the SL-PLUS hip stem, we performed a prospective double blind randomised controlled trial comparing the early migration of the hydroxyapatite (HA)-coated SL-PLUS stem compared to the Standard (non-coated) SL-PLUS stem. 51 patients were randomly assigned to receive either an uncoated or a HA-coated femoral component during total hip replacement. RSA images were obtained direct postoperatively and at 6 weeks, 12 weeks, 6 months, 12 months and 24 months. HOOS scores were obtained preoperative and at final follow-up. RSA evaluation demonstrated significant migration up to 3 months postoperatively in both groups. After initial setting no significant migration was observed. There was no significant difference in migration between the HA-coated group and the uncoated group.Both Harris Hip Score (HHS) and HOOS domain scores (pain and ADL) significantly improved compared to baseline at 24 months after surgery in both treatment groups (p<0.001 for all comparisons). Improvement did not differ significantly between the 2 groups. At 2 years follow-up, the HA-coated and uncoated Zweymuller type, distal fitting stem do not show different migration patterns.

  20. Effects of choline chloride on electrodeposited Ni coating from a Watts-type bath

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yurong; Yang, Caihong; He, Jiawei; Wang, Wenchang [School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Mitsuzak, Naotoshi [Qualtec Co., Ltd, Osaka 590-0906 (Japan); Chen, Zhidong, E-mail: zdchen.lab@gmail.com [School of Material Science and Engineering, Jiangsu Key Laboratory of Materials, Surface and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Advanced Catalytic Material and Technology, Changzhou University, Changzhou 213164 (China)

    2016-05-30

    Graphical abstract: - Highlights: • ChCl was applied as additive and conducting salt in Watts-type bath. • Progressive addition of ChCl leads to the crystal orientation (1 1 1) predominant. • The grain size and microhardness were refined and enhanced by increasing ChCl. • ChCl could be a good alternative to NiCl{sub 2} and additives for bright Ni electroplating. - Abstract: Electrodeposition of bright nickel (Ni) was carried out in a Watts-type bath. Choline chloride (ChCl) was applied as a multifunctional additive and substitute for nickel chloride (NiCl{sub 2}) in a Watts-type bath. The function of ChCl was investigated through conductivity tests, anodic polarization, and cathodic polarization experiments. The studies revealed that ChCl performed well as a conducting salt, anodic activator, and cathodic inhibitor. The effects of ChCl on deposition rate, preferred orientation, grain size, surface morphology, and microhardness of Ni coatings were also studied. The deposition rate reached a maximum value of greater than 27 μm h{sup −1} when 20 g L{sup −1} ChCl was introduced to the bath. Using X-ray diffraction, it was confirmed that progressive addition of ChCl promoted the preferred crystal orientation modification from (2 0 0) and (2 2 0) to (1 1 1), refined grain size, and enhanced microhardness. The presence of ChCl lowered the roughness of the coating.

  1. Cytotoxicity Induced by Engineered Silver Nanocrystallites Is Dependent on Surface Coatings and Cell Types

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, Anil K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Pelletier, Dale A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Wang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division; Morrell-Falvey, Jennifer L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Gu, Baohua [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division; Doktycz, Mitchel J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)

    2012-01-04

    Due to their unique antimicrobial properties silver nanocrystallites have garnered substantial recognition and are used extensively in biomedical applications such as wound dressing, surgical instruments and as bone substitute material. They are also released into unintended locations such as the environment or biosphere. Therefore it is imperative to understand the potential interactions, fate and transport of nanoparticles with environmental biotic systems. Although numerous factors including the composition, size, shape, surface charge and capping molecule of nanoparticles are known to influence the cell cytotoxicity, our results demonstrate for the first time that surface coatings are a major determinant in eliciting the potential cytotoxicity and cell interactions of silver nanoparticles. In the present investigation, silver nanocrystallites with nearly uniform size and shape distribution but with different surface coatings, imparting overall high negativity to high positivity, were synthesized. These nanoparticles were poly (diallyldimethylammonium) chloride-Ag, biogenic-Ag, colloidal-Ag (uncoated) and oleate-Ag with zeta potentials +45±5 mV, -12± 2 mV, -42±5 mV and -45±5 mV respectively; the particles were thoroughly purified so as to avoid false cytotoxicity interpretations. A systematic investigation on the cytotoxic effects, cellular response and membrane damage caused by these four different silver nanoparticles were evaluated using multiple toxicity measurements on mouse macrophage (RAW-264.7) and lung epithelial (C-10) cell lines. From a toxicity perspective, our results clearly indicated that the cytotoxicity was depend on various factors such as synthesis procedure, surface coat or surface charge and the cell-type for the different silver nanoparticles that were investigated. Finally, poly (diallyldimethylammonium) chloride -Ag was found to be the most toxic, followed by biogenic-Ag and oleate-Ag, whereas uncoated-Ag was found to be least toxic

  2. Characteristics of white coat hypertension in Chinese Han patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Zhou, Jianguang; Liu, Changyun; Shan, Peijia; Zhou, Yingqi; Xu, Erli; Ji, Yufeng

    2014-01-01

    This study documented the prevalence and clinical features of white coat hypertension (WCH) among Chinese Han patients with type 2 diabetes mellitus (T2DM). Clinic and ambulatory blood pressure (BP) measurements were compared in 856 patients with T2DM to determine the frequency of WCH (WCH was defined as clinical blood pressure ≥140/90 mmHg and daytime blood pressure hypertension. Age, course of T2DM, male WC were independent protective factors, whereas female sex, smoking and alcohol consumption were independent risk factors for WCH in T2DM. Non-dippers and reverse dippers made up larger proportion of the WCH group (p hypertension (EH), and WCH patients also exhibit significant differences in clinical parameters.

  3. Drug release from kollicoat SR 30D-coated nonpareil beads: Evaluation of coating level, plasticizer type, and curing condition

    OpenAIRE

    Shao, Zezhi J.; Morales, Luis; Diaz, Steven; Muhammad, Nouman A.

    2002-01-01

    A newly available polyvinylacetate aqueous dispersion, Kollicoat SR 30D, was evaluated with respect to its ability to modulate the in vitro release of a highly water-soluble model compound (diphenhydramine hydrochloride) from nonpareil-based systems. Kollicoat SR 30D premixed with a selected plasticizer (10% wt/wt propylene glycol, 2.5% triethyl citrate, or 2.5% dibutyl sebacute), talc, and red #30 lake dye was coated onto the drug beads in an Aeromatic Strea I fluid-bed drier with a Wurster ...

  4. Enhancing the biological activity of immobilized osteopontin using a type-1 collagen affinity coating.

    Science.gov (United States)

    Martin, Stephanie M; Schwartz, Jeffrey L; Giachelli, Cecilia M; Ratner, Buddy D

    2004-07-01

    The covalent attachment of biomolecules onto surfaces represents a step toward the improvement of biomaterial properties by providing relevant biological signals of interest to the cell culture or tissue environment. The chemistries involved, however, often attach proteins to the surface in a random fashion, rather than the conformation or orientation most easily recognized by cells and other proteins both in vitro and in vivo. An alternative approach is to take advantage of natural interactions to both bind and orient a biomolecule "naturally," thereby enhancing its biological activity. Type 1 collagen has been shown to bind to osteopontin (OPN), a protein implicated in processes such as wound healing, endothelial cell survival, and angiogenesis. This study seeks to characterize, quantify, and exploit this interaction in order to present a more naturally recognized form of OPN to the environment surrounding a biomaterial. Binding of OPN to type 1 collagen was confirmed using Surface Plasmon Resonance (SPR). Radio-iodination of OPN showed that binding to collagen was dose-dependent and maximal in basic conditions. Principal component analysis of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) data identified differences in OPN immobilized via different techniques. Adhesion of bovine aortic endothelial cells on OPN immobilized using the affinity coating was also significantly enhanced compared to controls. Investigation into the in vivo relevance of this immobilization method is currently underway. Copyright 2004 Wiley Periodicals, Inc.

  5. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masahiro, E-mail: goto.masahiro@nims.go.jp [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sasaki, Michiko [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Xu, Yibin [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Materials Database Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhan, Tianzhuo [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Isoda, Yukihiro [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Shinohara, Yoshikazu [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2017-06-15

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  6. Microstructural and aqueous corrosion aspects of laser-surface-melted type 304 SS plasma-coated mild steel

    Science.gov (United States)

    Pujar, M. G.; Dayal, R. K.; Singh Raman, R. K.

    1994-06-01

    Plasma spray deposition of metals, ceramics, or plastics onto base metals to produce wear- and corrosion-resistant surfaces is a promising technique whereby base metal performance can be considerably im-proved. Because these coatings invariably contain pores, voids, and cracks, laser surface melting may be employed to improve their homogeneity. This study focuses on the corrosion performance of laser- sur-face- melted type 304 SS plasma- coated mild steel specimens. Mild steel strips were plasma coated with an approximately 100 to 200 μm thick layer of type 304 by transferred plasma jet. These specimens were sub-sequently laser irradiated using a 3 kW continuous- wave CO2 gas laser. Eight different sets of specimens were selected based on different laser beam travel speeds. Scanning electron microscopic studies of the plasma- coated specimens revealed both pancake and flowery types of deposited particles. Optical micro-scopic studies followed by anodic polarization experiments were carried out on these specimens in IN H2SO4 medium. It was observed that specimens with laser beam interaction times ranging from 30 to 120 ms showed relatively better general corrosion performance than specimens with interaction times of from 15 to 24 ms.

  7. The Effects of the Thickness and Type of Silicone Coating Materials on the Swelling Behaviour of Hydrogels

    Science.gov (United States)

    Radzi, Zamri; Lee, J. Hannah; Swan, Marc; Goodacre, Tim; Bucknall, David; Czernuszka, Jan

    2010-03-01

    Encapsulation is one of the methods to control the degree of hydrogel swelling. In certain medical applications the hydrogels are required to undergone slow initial swelling before they start to gradually swell up to their maximum swelling capacity. Using a dip coating technique, the anisotropic hydrogels were coated with different types of silicone dispersion formulations. The hydrogels were swelled and measured by determining the mass change as a function of time. By varying the coating thickness and concentration of silicone we found that it is possible to slow down the initial swelling and allow the subsequent swelling process to gradually take place to physiologically acceptable levels. This behaviour has been analysed in terms of the permeability to water of the silicone membranes and their mechanical properties.

  8. Effect of different types of coatings on texture and nutritional properties of canned Portuguese sardines (Sardina pilchardus

    Directory of Open Access Journals (Sweden)

    Rita Pinheiro

    2014-06-01

    Full Text Available Canned foods have a long history of success and are likely to remain popular for the foreseeable future owing to their convenience, long shelf life and economy. Interest in fish consumption has increased in recent years due to the wide range of its health benefits. In addition to fresh product, canned fish enables a delayed consumption of this appreciated kind of food. Among the different types of fish, in Portugal, the most used in canning manufacture are sardines, tuna, anchovies, mackerels. Vegetable oils and tomato sauce are usually adopted as coatings (liquid medium. In fact, oil has a preserving effect and contributes to make the product more palatable. Its protective action lies in the ability to insulate products from air, rather than having an active bacteriostatic or bactericidal action. Among the different types of coatings the most commonly used in canning are: olive oil, seed oils and different sauces, such as tomato sauce. Tomato sauce has also vegetable oil on its formulation. The amount of coating substance can affect the nutritional composition as well as texture properties of the sardines. The aim of this work was to investigate the effect of different types of coatings on texture and nutritional properties of whole, skinless and boneless canned Portuguese Sardines (Sardina pilchardus. An experimental investigation was carried out to assess the protein, lipid, carbohydrates and ash content, texture and colour profile of canned sardine with different kinds of coatings: olive oil, sunflower oil and tomato sauce. The obtained results showed that protein and carbohydrates content were not significantly influenced by the coating used, varying between 5%-8% and13%-18%, respectively. For the moisture content it was found that the samples with tomato sauce were 2.2-fold higher than the samples with sunflower oil, and 1.3-fold higher than the samples with olive oil, independently of being whole, skinless or boneless sardine. As

  9. Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering.

    Science.gov (United States)

    Lee, Mun-Hwan; You, Changkook; Kim, Kyo-Han

    2015-03-16

    In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP) scaffolds. Surface characterization using a scanning electron microscope (SEM) and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups. MG63 cells were used to evaluate cell proliferation and ALP activity on the modified BCP scaffolds. The modified microporous surfaces showed low contact angles and large surface areas, which enhanced cell spreading and proliferation. Coating of the BCP scaffolds with type I collagen led to enhanced cell-material interactions and improved MG63 functions, such as spreading, proliferation, and differentiation. The micropore/collagen-coated scaffold showed the highest rate of cell response. These results indicate that a combination of micropores and collagen enhances cellular function on bioengineered bone allograft tissue.

  10. PREPARATION OF ZEOLITE X COATINGS ON SODA-LIME TYPE GLASS PLATES

    Directory of Open Access Journals (Sweden)

    M. Tatlier

    Full Text Available Abstract The dissolution of glass in highly alkaline reaction mixtures and the impact of this phenomenon on zeolite coating formation were investigated. Coating samples were prepared and characterized by X-ray diffraction (XRD, field emission gun scanning electron microscopy (FEGSEM and thermogravimetry (TG. It was demonstrated that zeolite X coatings might be prepared on soda-lime glass. Glass dissolved to some degree, up to 2% of its original mass, in the reaction mixtures for the conditions investigated. This dissolution affected the zeolite synthesis taking place on the glass surface, resulting in phases different from those obtained on inert metal surfaces in some cases, especially for the use of reaction mixtures with relatively high Si/Al ratios. The percentage of dissolution of glass plates increased with their decreasing thickness, indicating a surface phenomenon for the dissolution. The stabilities of the coatings, which varied with the synthesis conditions, benefited from the addition of extra thin layers of polyacrylic acid.

  11. The generation of Turnip crinkle virus-like particles in plants by the transient expression of wild-type and modified forms of its coat protein

    Directory of Open Access Journals (Sweden)

    Keith eSaunders

    2015-12-01

    Full Text Available Turnip crinkle virus (TCV, a member of the genus carmovirus of the Tombusviridae family, has a genome consisting of a single positive-sense RNA molecule that is encapsidated in an icosahedral particle composed of 180 copies of a single type of coat protein. We have employed the CPMV-HT transient expression system to investigate the formation of TCV-like particles following the expression of the wild-type coat protein or modified forms of it that contain either deletions and/or additions insertions. Transient expression of the coat protein in plants results in the formation of capsid structures that morphologically resemble TCV virions (T=3 structure but encapsidate heterogeneous cellular RNAs, rather than the specific TCV coat protein messenger RNA. Expression of an amino-terminal deleted form of the coat protein resulted in the formation of smaller T=1 structures that are free of RNA. The possibility of utilising TCV as a carrier for the presentation of foreign proteins on the particle surface was also explored by fusing the sequence of GFP to the C-terminus of the coat protein. The expression of coat protein-GFP hybrids permitted the formation of VLPs but the yield of particles is diminished compared to the yield obtained with unmodified coat protein. Our results confirm the importance of the N-terminus of the coat protein for the encapsidation of RNA and show that the coat protein’s exterior P domain plays a key role in particle formation.

  12. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    Science.gov (United States)

    Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

    2017-06-01

    p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p-n modules of bismuth telluride without any doping process.

  13. Investigation of novel heterojunction: P-type SnS coated n-type ZnO nanowire

    Science.gov (United States)

    Bu, Ian Y. Y.

    2015-12-01

    SnS coated ZnO nanowires heterojunctional solar cells were fabricated using a combination of hydrothermal synthesis and chemical bath deposition (CBD) method. The synthesized materials and devices were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), photoluminescence emission spectroscopy, Uv-Vis spectroscopy and electrical measurements. SEM imaging of the sample revealed that the CBD SnS coating bunches the underlying ZnO nanowires due to the large capillary force it experiences during the drying process. Both of the EDS and XRD measurements confirm the presence of SnS and SnO2. Optoelectronic measurement confirms that the fabricated device exhibit high absorbance (∼80%) and exhibit photovoltaic behaviour.

  14. Osteogenicity of titanium implants coated with calcium phosphate or collagen type-I in osteoporotic rats

    NARCIS (Netherlands)

    Alghamdi, H.S.A.; Bosco, R.; Beucken, J.J. van den; Walboomers, X.F.; Jansen, J.A.

    2013-01-01

    This study hypothesized that modification of titanium implant surface, e.g. by the deposition of inorganic/organic coatings, can significantly improve the implant-bone response compared in osteoporotic vs. healthy conditions. After osteoporosis was induced in 15 female Wistar rats by ovariectomy

  15. The effect of coatings and coating weight by two types of PCC on barrier and optical properties and roughness of paper

    Directory of Open Access Journals (Sweden)

    rouzbeh asadi khansari

    2017-08-01

    Full Text Available The objective of this work is to investigate the use of PCC, and the impact of its coating weight on paper coating. In this study, two base papers from Mazandaran Wood and Paper Industries (APC and NS, and two coating compositions with the solid content of 25% containing PCC filler (100 parts, PVA binder (14 parts and dispersant (1 part were used. The first composition included PCC B102 for opacity increment, and the second one PCC 9020 for the improvement of brightness. Two rod RDS14 and RDS30 were used for different coating weights. After coating, the treated samples were dried in room conditions at air temperature of 25◦C and relative humidity of 54%. Physical and optical properties of control and treated samples such as air resistance, thickness, Cobb60, brightness, yellowness, opacity and roughness were determined. In comparison to the control group, all the treated samples showed improvement in brightness, opacity, yellowness and air resistance. By the two different formulations and two rods, paper roughness was increased, and the increment of water absorption was due to capillary development in coating texture. The analysis of variances showed that the usage of PCC 9020 had considerable effect on roughness of papers. In NS papers, change of PCC caused significant difference in brightness and roughness, but in APC papers did not. The change of coating rod in APC papers had significant effect on water absorption, brightness and opacity but did not show in NS.

  16. Contamination profile of Printed Circuit Board Assemblies in relation to soldering types and conformal coating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition...... by an appropriate cleaning. Selective soldering process generates significantly higher levels of residues compared to the wave and reflow process. For conformal coated PCBAs, the contamination levels generated from the tested wave and selective soldering process are found to be enough to generate blisters under...... by measuring the leak current using a twin platinum electrode setup. Localized extraction of residue was carried out using a commercial C3 extraction system. Results clearly show that the amount and distribution of flux residues are a function of the soldering process, and the level can be reduced...

  17. Improved charge separation efficiency of hematite photoanodes by coating an ultrathin p-type LaFeO3 overlayer

    Science.gov (United States)

    Fang, Tao; Guo, Yongsheng; Cai, Songhua; Zhang, Ningsi; Hu, Yingfei; Zhang, Shiying; Li, Zhaosheng; Zou, Zhigang

    2017-09-01

    Many metal-oxide candidates for photoelectrochemical water splitting exhibit localized small polaron carrier conduction. Especially hematite (α-Fe2O3) photoanodes often suffer from low carrier mobility, which causes the serious bulk electron-hole recombination and greatly limits their PEC performances. In this study, the charge separation efficiency of hematite was enhanced greatly by coating an ultrathin p-type LaFeO3 overlayer. Compared to the hematite photoanodes, the solar water splitting photocurrent of the Fe2O3/LaFeO3 n-p junction exhibits a 90% increase at 1.23 V versus the reversible hydrogen electrode, due to enlarging the band bending and expanding the depletion layer.

  18. Preparation and characterisation of Chlorogenic acid-gelatin: A type of biologically active film for coating preservation.

    Science.gov (United States)

    Fu, Shalu; Wu, Chunhua; Wu, Tiantian; Yu, Haixia; Yang, Shuibing; Hu, Yaqin

    2017-04-15

    Chlorogenic acid (CGA), a type of plant polyphenol, was conjugated onto gelatin (Gel) to prepare a novel coating material for the preservation of fresh seafood. The optimal reaction molar ratio of CGA to gelatin (4:1) was determined according to the CGA content in the CGA-Gel conjugate. CGA was confirmed to be successfully conjugated onto gelatin by 1H nuclear magnetic resonance and Fourier transform-infrared spectroscopy. The antioxidant activity of CGA-Gel was proven to be higher than that of the free CGA in 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) radical scavenging, hydrogen peroxide scavenging, ferric ion reducing power and lipid oxidation assays. The minimum inhibitory concentrations (MIC) of CGA against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus were 1, 1, 2 and 2mg/mL, respectively. The antibacterial activity of CGA-Gel was unaffected by conjugation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. New type of protective hybrid and nanocomposite hybrid coatings containing silver and copper with an excellent antibacterial effect especially against MRSA

    Energy Technology Data Exchange (ETDEWEB)

    Slamborova, Irena [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic); Zajicova, Veronika, E-mail: veronika.zajicova@tul.cz [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic); Karpiskova, Jana [Institute of Novel Technologies and Applied Informatics, Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentska 2, 461 17 Liberec 1 (Czech Republic); Exnar, Petr; Stibor, Ivan [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic)

    2013-01-01

    Epidemics spread many types of pathogenic bacterial strains, especially strains of MRSA (Methicillin-resistant Staphylococcus aureus), which are being increasingly reported in many geographical areas [1]. This is becoming to be a serious global problem, particularly in hospitals. Not only are antibiotics proving to be increasingly ineffective but also the bacteria responsible for more than 70% of hospital-acquired bacterial infections are resistant to at least one of the drugs commonly used to treat them. In this study, hybrid coating A1 and nanocomposite hybrid coating A2 based on TMSPM (3-(trimethoxysilyl)propyl methacrylate, MMA (methyl methacrylate), TEOS (tetraethyl orthosilicate) and IPTI (titanium isopropoxide) containing silver and copper ions with or without nanoparticles of titanium dioxide were prepared by the sol-gel method. They were deposited on glass, poly(methyl methacrylate) and cotton using dip-coating or spin-coating, and then cured at 150 Degree-Sign C for 3 h or, in the case of poly(methyl methacrylate), at 100 Degree-Sign C for 4.5 h. The morphology and microstructure of these hybrid coatings were examined by SEM. The abrasion resistance was tested using a washability tester and found to depend heavily on the curing temperature. Seven types of bacterial strains were used to determine the profile of antibacterial activity, namely Escherichia coli, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus - MRSA (CCM 4223), MRSA-2 (CCM 7112), Acinetobacter baumanii, Pseudomonas aeruginosa, and Proteus vulgaris (according to ALE-G18, CSNI). All the samples were tested by irradiating with either a UV-A or a daylight fluorescent lamp. All types of hybrid coating A1 and nanocomposite hybrid coating A2 were found to possess an excellent antibacterial effect, including against the pathogenic bacterial strains of MRSA, which present a dangerous threat on a global scale.

  20. Vildagliptin loaded triangular DNA nanospheres coated with eudragit for oral delivery and better glycemic control in type 2 diabetes mellitus.

    Science.gov (United States)

    Baig, Mirza Muhammad Faran Ashraf; Khan, Sara; Naeem, Muhammad Ahsan; Khan, Ghulam Jilany; Ansari, Muhammad Tayyab

    2017-11-13

    Diabetes mellitus type 2 is a multidimensional disease associated with poor glycemic control through compromised sensitivity of pancreatic islet α and β cells against glucose and dwindled secretion of insulin which is linked with the quantity of incretin hormones that are abridged by dipeptidyl peptidase-4 (DPP-4) in diseased condition. Vildagliptin (VG) inhibits DPP-4 therefore regulates the incretins that conversely maintains glycemic control. The safe reach and absorption of VG from intestine was dubious. Therefore we used Electrostatic Attraction Method to develop drug loaded DNA nanotechnology triangles coated by Eudragit (Eud) to make stable nanospheres of Vildagliptin (VG). We further analyzed the formulated nanospheres by AFM, XRD, DSC, SEM, TGA, ATR-FTIR and native PAGE. Additionally the efficacy of formulated nanospheres for drug release and glycemic control was assessed in Db/Db mouse. Our results showed that formulated nanospheres are smooth, spherical, stable and uniform in size ranging from 500 to 2000 nm with drug entrapment efficiency up to 95 ± 2% and extended drug release up to 15 ± 2 h. FTIR and DSC results confirmed the absence of VG-DNA-Eud interaction and XRD studies revealed a change in the crystalline status of the VG in nanospheres. Ex-vivo studies indicate that Eud-DNA-VG nanospheres effectively bypasses the acidic pH of the stomach and enhances glycemic control in Db/Db mouse without any risk of pancreatitis or pancreatic cancer. To the best of our knowledge, this is the first study conclusively reporting that VG loaded DNA Nano-architects coated with Eudragit are stable, safe and may improve therapeutic outcomes after oral delivery. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Preparation and electrochemical properties of Li-rich spinel-type lithium manganate coated LiMn{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yumei; Lin, Zhenzhen [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Li, Yongliang [Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China); Chen, Caifeng; He, Yi [College of Chemistry, Beijing Normal University, Beijing 100875 (China); Yang, Xiaojing, E-mail: yang.xiaojing@bnu.edu.cn [College of Chemistry, Beijing Normal University, Beijing 100875 (China)

    2011-12-15

    Graphical abstract: Composites in which Li-rich spinel-type lithium manganate was coated on surface of LiMn{sub 2}O{sub 4} particles were prepared, and the cycling stabilities of composites were much improved. Highlights: Black-Right-Pointing-Pointer A composite of Li-rich spinel-type lithium manganate and LiMn{sub 2}O{sub 4}. Black-Right-Pointing-Pointer Li-rich spinel-type lithium manganate coating on the surface of LiMn{sub 2}O{sub 4} particles. Black-Right-Pointing-Pointer A synthetic method of sol-gel followed by heating. Black-Right-Pointing-Pointer Improved cycling stability without large degradation of initial capacity. -- Abstract: Li-rich spinel-type lithium manganate (SC) coated LiMn{sub 2}O{sub 4} composites were prepared and characterized by XRD, SEM, FT-IR, ICP, etc. Their charge/discharge behaviors were studied between 3.0 and 4.3 V at 40 mA g{sup -1} under room temperature, and the results showed that SC coated on surface of LiMn{sub 2}O{sub 4} could improve cycling stability of composite electrodes. The composite (S1) containing 4.8 wt% of SC exhibited noticeably improved cycling stability, whereas the initial specific capacity was very close to that of LiMn{sub 2}O{sub 4}.

  2. Profiling the Phenolic Compounds of the Four Major Seed Coat Types and Their Relation to Color Genes in Lentil.

    Science.gov (United States)

    Mirali, Mahla; Purves, Randy W; Vandenberg, Albert

    2017-05-26

    Phenolic compounds can provide antioxidant health benefits for humans, and foods such as lentils can be valuable dietary sources of different subclasses of these secondary metabolites. This study used LC-MS analyses to compare the phenolic profiles of lentil genotypes with four seed coat background colors (green, gray, tan, and brown) and two cotyledon colors (red and yellow) grown at two locations. The mean area ratio per mg sample (MARS) values of various phenolic compounds in lentil seeds varied with the different seed coat colors conferred by specific genotypes. Seed coats of lentil genotypes with the homozygous recessive tgc allele (green and gray seed coats) had higher MARS values of flavan-3-ols, proanthocyanidins, and some flavonols. This suggests lentils featuring green and gray seed coats might be more promising as health-promoting foods.

  3. Development of an asymmetric PCR-ELISA typing method for citrus tristeza virus based on the coat protein gene.

    Science.gov (United States)

    Nolasco, G; Santos, C; Silva, G; Fonseca, F

    2009-02-01

    The coat protein gene of isolates of citrus tristeza virus (CTV) from 20 citrus-producing regions around the world was amplified by RT-PCR, TA cloned, and characterized by SSCP. Haplotypes that produced different patterns within each geographic region were sequenced and a database of 153 accessions of CTV was assembled. Phylogenetic analysis revealed the existence of seven well-defined clusters (Coefficient of differentiation 0.78). An asymmetric PCR-ELISA typing (APET) assay was developed in the frame of this clustering pattern using a set of eight hybridisation probes. The membership of any unknown haplotype is determined by comparing its pattern of reaction against the whole set of probes and not, as previously done in hybridisation assays, in an all-or-nothing basis. Interpretation of the results is objective and done through a visual basic application that compares the rates of hydrolysis of the ELISA substrate of an assayed isolate to a matrix of rates of hydrolysis obtained from standard haplotypes. This assay was validated and showed a better ability to resolve haplotypes than other assays to which it was compared experimentally. It may be automated to the same extent as any ELISA.

  4. Bioactivities of Jc-SCRIP, a type 1 ribosome-inactivating protein from Jatropha curcas seed coat.

    Science.gov (United States)

    Nuchsuk, Chanthakan; Wetprasit, Nuanchawee; Roytrakul, Sittiruk; Choowongkomon, Kiattawee; T-Thienprasert, Nattanan; Yokthongwattana, Chotika; Arpornsuwan, Theerakul; Ratanapo, Sunanta

    2013-10-01

    In this study, a type 1 RIP, designated as Jc-SCRIP, was first isolated from the seed coat of Jatropha curcas Linn. It was purified by ammonium sulfate precipitation and chromatography on DEAE-Sephacel™ and CM-cellulose columns. Purification fold of Jc-SCRIP increased 113.8 times, and the yield was 1.13% of the total protein in the final step. It was shown to be a monomeric glycoprotein with a molecular mass of 38 938 Da, as determined by MALDI-TOF/MS. It exhibited hemagglutination activity and possessed strong N-glycosidase activity. The antimicrobial activity of Jc-SCRIP was tested against nine human pathogenic bacteria and one fungus; the most potent inhibitory activity was against Staphylococcus epidermidis ATCC 12228, with minimum inhibitory concentration value of 0.20 μm. Jc-SCRIP demonstrated in vitro cytotoxicity against human breast adenocarcinoma cell line (MCF-7), a colon adenocarcinoma (SW620), and a liver carcinoma cell line (HepG2), with IC50 values of 0.15, 0.25, and 0.40 mm, respectively. The results suggested that Jc-SCRIP may be a potential natural antimicrobial and anticancer agent in medical applications. © 2013 John Wiley & Sons A/S.

  5. Cytotoxicity of β-D-glucose/sucrose-coated silver nanoparticles depends on cell type, nanoparticles concentration and time of incubation

    Science.gov (United States)

    Vergallo, Cristian; Panzarini, Elisa; Carata, Elisabetta; Ahmadi, Meysam; Mariano, Stefania; Tenuzzo, Bernardetta Anna; Dini, Luciana

    2016-06-01

    The use of silver NanoParticles (AgNPs) in several consumer commercialized products, like food contact materials, medical devices and cosmetics has increased significantly, owing to their antibacterial and antifungal properties. Even though the NPs are widely diffused, due to the great variety in size, coating or shape, controversial data on their possible detrimental health effects still exist. Herein, by performing an easy and fast green method synthesis, we used β-D-glucose/sucrose to stabilize AgNPs and avoid the release of cytotoxic soluble silver ions Ag+ in the culture medium. The cytotoxic effects of these β-D-Glucose/Sucrose-Coated AgNPs (AgNPs-GS) was assessed on two cell culture models, which are human liver HepG2 and human Peripheral Blood Lymphocytes (PBLs) cells. AgNPs-GS, as determined by Transmission Electron Microscopy (TEM) analyses, had an average diameter of 30±5 nm, a spherical shape and were well-dispersed in the freshly-prepared solution. In addition, they were found spectrophotometrically stable throughout the experiment. Cytotoxicity, determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay, was evaluated by using two AgNPs-GS amounts, indicated as highest (10×103 of NPs/cell) and lowest (2×103 NPs/cell) concentration for 6, 12 and 24 h. The highest concentration of AgNPs-GS was significantly cytotoxic for both HepG2 and PBLs cells at all times, when compared with the negative control; conversely, the lowest amount of AgNPs-GS was toxic only for HepG2 cells. A significant increase of Reactive Oxygen Species (ROS) levels, determined by Nitro Blue Tetrazolium (NBT) reduction assay, was observed only in PBLs after treatment with NPs, by reaching maximum levels after the incubation with the lowest amount of NPs for 24 h. Significant morphological changes, depending on NPs/cell amount, characteristic of cell toxicity, like shape, cytoplasm, and nucleus alterations, were observed in lymphocytes and Hep

  6. Effect of an edible crosslinked coating and two types of packaging on antioxidant capacity of castilla blackberries

    Directory of Open Access Journals (Sweden)

    Leidy Carolina Ayala Sánchez

    2014-06-01

    Full Text Available In order to increase the shelf life and maintain the quality and stability of the biological compounds with antioxidant activity present in Castilla blackberry fruits, a sodium alginate-based edible crosslinked coating was applied, and the fruits were packed in two different plastic containers and stored under refrigeration (3 ± 1 °C. Total antioxidant capacity and its relationship to physicochemical variables such as pH, Brix, and acidity were evaluated in six treatments: uncoated blackberry stored in a macroperforated container (T1 and thermosealed container (T2, without crosslinked coating in a macroperforated container (T3 and thermosealed container (T4, with crosslinked coating (calcium ions packed in macroperforated container (T5 and thermosealed container (T6. The results indicated that factors such as gas permeability in the coatings, the packaging used, and physicochemical parameters significantly affected the fruit total antioxidant capacity, with the highest level in T1 (0.22 µgEAA/ml at the end of the essay, which is related to the lowest levels of pH and direct exposure to air. On the other hand, the lowest value was obtained in T6 (0.16 µgEAA/ml due to the crosslinked coating, packaging in the thermosealed container, and higher pH value. Variations in acidity, Brix, and pH indicate the presence of degenerative processes in the crosslinked coating treatments, which limited the physicochemical changes.

  7. Evaluation of HVOF coatings

    Directory of Open Access Journals (Sweden)

    Mariana Landová

    2016-07-01

    Full Text Available Attention in this paper is devoted to the evaluation of wear coatings deposited using HVOF technology (high velocity oxy-fuel. There were evaluated three types of coatings based on WC-Co (next only 1343, WC-Co-Cr (next only 1350 and Cr3C2-25NiCr (next only 1375. There was assessed adherence of coatings, micro hardness, porosity and the tribological properties of erosive, abrasive, adhesive and wear resistance of coatings in terms of cyclic thermal load. Thanks to wide variety of suitable materials and their combinations, the area of utilization thermally sprayed coatings is very broad. It is possible to deposit coatings of various materials from pure metals to special alloys. The best results in the evaluated properties were achieved at the coating with the label 1375.

  8. Investigation of Thermostressed State of Coating Formation at Electric Contact Surfacing of “Shaft” Type Parts

    Directory of Open Access Journals (Sweden)

    Olena V. Berezshnaya

    2016-01-01

    Full Text Available The forming of coating at electric contact surfacing is considered. The mathematical model of the coating formation is developed. The method of numerical recurrent solution of the finite-difference form of static equilibrium conditions of the selected elementary volume of coating is used. This model considers distribution of thermal properties and geometric parameters along the thermal deformation zone during the process of electric contact surfacing by compact material. It is found that the change of value of speed asymmetry factor leads to increasing of the friction coefficient in zone of surfacing. This provides the forming of the coating of higher quality. The limitation of the technological capabilities of equipment for electric contact surfacing is related to the size of recoverable parts and application of high electromechanical powers. The regulation of the speed asymmetry factor allows for expanding the technological capabilities of equipment for electric contact surfacing. The nomograms for determination of the stress on the roller electrode and the finite thickness of the coating as the function of the initial thickness of the compact material and the deformation degree are shown.

  9. Antibacterial silver nanocluster/silica composite coatings on stainless steel

    Science.gov (United States)

    Ferraris, M.; Perero, S.; Ferraris, S.; Miola, M.; Vernè, E.; Skoglund, S.; Blomberg, E.; Odnevall Wallinder, I.

    2017-02-01

    A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel surface compared with a control surface. The antibacterial coating retained its antibacterial activity after thermal treatment up to 450 °C and after soaking in common cleaning products for stainless steel surfaces used for e.g. food applications. The antibacterial capacity of the coating remained at high levels for 1-5 days, and showed a good capacity to reduce the adhesion of bacteria up to 30 days. Only a few

  10. Biological response to titanium implants coated with nanocrystals calcium phosphate or type 1 collagen in a dog model

    NARCIS (Netherlands)

    Alghamdi, H.S.A.; Oirschot, B.A. van; Bosco, R.; Beucken, J.J. van den; Aldosari, A.A.; Anil, S.; Jansen, J.A.

    2013-01-01

    OBJECTIVE: The current study aimed to evaluate the osteogenic potential of electrosprayed organic and non-organic surface coatings in a gap-implant model over 4 and 12 weeks of implantation into the dog mandible. MATERIAL AND METHODS: Sixteen Beagle dogs received experimental titanium implants in

  11. Coat protein deletion mutants elicit more severe symptoms than wild-type virus in multiple cereal hosts

    Science.gov (United States)

    The coat protein (CP) of Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. This study demonstrates that deletion of CP amino acids 58 to 84, but not 36 to 57, from WSMV genome induced severe ...

  12. The potential of nano-structured silicon oxide type coatings deposited by PACVD for control of aquatic biofouling

    NARCIS (Netherlands)

    Akesso, L.; Pettitt, M.E.; Callow, J.A.; Callow, M.E.; Stallard, J.; Teer, D.; Liu, C.; Wang, S.; Zhao, Q.; D'Souza, F.; Willemsen, P.R.; Donnelly, G.T.; Donik, C.; Kocijan, A.; Jenko, M.; Jones, L.A.; Guinaldo, P.C.

    2009-01-01

    SiOx-like coatings were deposited on glass slides from a hexamethylsiloxane precursor by plasma-assisted CVD (PACVD). Surface energies (23.1-45.7 mJ m-1) were correlated with the degree of surface oxidation and hydrocarbon contents. Tapping mode AFM revealed a range of surface topologies with Ra

  13. Fabrication of selenization-free superstrate-type CuInS{sub 2} solar cells based on all-spin-coated layers

    Energy Technology Data Exchange (ETDEWEB)

    Cheshme khavar, Amir Hossein [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Mahjoub, Alireza, E-mail: mahjouba@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Samghabadi, Farnaz Safi [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Taghavinia, Nima, E-mail: taghavinia@sharif.edu [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of)

    2017-01-15

    Today manufacturing of high efficiency chalcogenide thin film solar cells is based on high cost vacuum-based deposition processes at high temperature (>500 °C) and in chalcogen -containing atmosphere. In this paper, we introduce a simple vacuum-free and selenization-free, solution processing for fabricating a superstrate-type CuInS{sub 2} (CIS) solar cell. The absorber, buffer and blocking layers were all deposited by spin coating of molecular precursor inks. We demonstrate the deposition of In{sub 2}S{sub 3} buffer layer by sol-gel spin casting for the first time. The rapid sintering process of CIS layer was carried out at 250 °C that is considered a very low temperature in CIGS thin-film technologies. A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. For the back contact we employed carbon, deposited by simple knife coating method. Different parameters including type of buffer, thickness of absorber layer, CIS and In{sub 2}S{sub 3} annealing temperature and morphology were optimized. Our air stable simple device structure consisting of showed promising power conversion efficiency (PCE) of 2.67%. - Highlights: • This work is an effort on the fabrication of all spin-coated CIS solar cells. • A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. • The best devices showed power conversion efficiency (PCE) of 2.67%.

  14. Microestrutura de uma Solda Dissimilar entre o Aço Inoxidável Ferrítico AISI 410S e o Aço Inoxidável Austenítico AISI 304L Soldado pelo Processo FSW

    Directory of Open Access Journals (Sweden)

    Tathiane Caminha Andrade

    2015-12-01

    Full Text Available Resumo O presente trabalho visa investigar a microestrutura formada na soldagem dissimilar entre chapas de aços inoxidáveis ferríticos AISI 410S e aços inoxidáveis austeníticos AISI 304L pelo processo friction stir welding. A soldagem foi realizada com o ajuste dos seguintes parâmetros: rotação 450 rpm; velocidade de soldagem de 1,0 mm/s; e força axial 40 kN. O aço AISI 410S foi posicionado no lado de avanço enquanto que o aço AISI 304L foi posicionado no lado de retrocesso. A análise consistiu de preparação metalográfica e caracterização microestrutural por microscopia ótica e microscopia eletrônica de varredura. Para o aço AISI 410S foi observada a formação de martensita associada com ferrita na zona de mistura (ZM, zona termomecanicamente afetada (ZTMA e na zona afetada pelo calor (ZAC. As características do processo de soldagem FSW resultaram num refino de grão para o aço inoxidável ferrítico, posicionado no lado de avanço, tanto na ZM quanto nas ZTMA e ZAC. O mesmo comportamento não foi observado para o lado austenítico.

  15. Experimental demonstration of a high-sensitivity humidity sensor based on an Agarose-coated transmission-type photonic crystal fiber interferometer.

    Science.gov (United States)

    Mathew, Jinesh; Semenova, Yuliya; Farrell, Gerald

    2013-06-01

    We present a detailed study of a high-sensitivity relative humidity (RH) sensor based on Agarose-coated transmission type photonic crystal fiber interferometer for what is the first time to our knowledge. The sensor shows a wavelength shift of approximately 56 nm for a humidity change of 58% RH. The repeatability of the coating layer formation and the evolution of the coating layers on passing the device though Agarose solution multiple times are studied in detail by observing the spectral shift resulting from the effect on the effective index of the cladding mode. Also, a detailed study is reported of the sensor performance in terms of its sensitivity, repeatability, and long-term stability. The sensor shows a linear response for an RH change in the range of 40%-80% RH with a humidity resolution of 0.017% RH and a higher humidity resolution of 0.007% RH in the range 80%-95% RH. The measurement accuracy of the sensor in the RH range 40%-80% is ±2% RH, and in the range 80%-95%, the accuracy is about ±1% RH. The response time of the sensor is 86 ms, when RH jumps from 50% to 90%. The temperature dependence of the sensor is found to be ~0.27 nm/°C, which is quite small compared to the RH sensitivity of the sensor.

  16. Effect of an edible crosslinked coating and two types of packaging on antioxidant capacity of castilla blackberries

    OpenAIRE

    Leidy Carolina Ayala Sánchez; Claudia Patricia Valenzuela Real; Yanneth Bohórquez Perez

    2014-01-01

    In order to increase the shelf life and maintain the quality and stability of the biological compounds with antioxidant activity present in Castilla blackberry fruits, a sodium alginate-based edible crosslinked coating was applied, and the fruits were packed in two different plastic containers and stored under refrigeration (3 ± 1 °C). Total antioxidant capacity and its relationship to physicochemical variables such as pH, Brix, and acidity were evaluated in six treatments: uncoated blackberr...

  17. A versatile and tunable coating strategy allows control of nanocrystal delivery to cell types in the liver.

    Science.gov (United States)

    Cormode, David P; Skajaa, Gitte O; Delshad, Amanda; Parker, Nicole; Jarzyna, Peter A; Calcagno, Claudia; Galper, Merav W; Skajaa, Torjus; Briley-Saebo, Karen C; Bell, Heather M; Gordon, Ronald E; Fayad, Zahi A; Woo, Savio L C; Mulder, Willem J M

    2011-03-16

    There are many liver diseases that could be treated with delivery of therapeutics such as DNA, proteins, or small molecules. Nanoparticles are often proposed as delivery vectors for such therapeutics; however, achieving nanoparticle accumulations in the therapeutically relevant hepatocytes is challenging. In order to address this issue, we have synthesized polymer coated, fluorescent iron oxide nanoparticles that bind and deliver DNA, as well as produce contrast for magnetic resonance imaging (MRI), fluorescence imaging, and transmission electron microscopy (TEM). The composition of the coating can be varied in a facile manner to increase the quantity of poly(ethylene glycol) (PEG) from 0% to 5%, 10%, or 25%, with the aim of reducing opsonization but maintaining DNA binding. We investigated the effect of the nanoparticle coating on DNA binding, cell uptake, cell transfection, and opsonization in vitro. Furthermore, we exploited MRI, fluorescence imaging, and TEM to investigate the distribution of the different formulations in the liver of mice. While MRI and fluorescence imaging showed that each formulation was heavily taken up in the liver at 24 h, the 10% PEG formulation was taken up by the therapeutically relevant hepatocytes more extensively than either the 0% PEG or the 5% PEG, indicating its potential for delivery of therapeutics to the liver.

  18. Heterologous minor coat proteins of Citrus tristeza virus strains affect encapsidation, but the coexpression of HSP70h and p61 restores encapsidation to wild-type levels.

    Science.gov (United States)

    Tatineni, Satyanarayana; Gowda, Siddarame; Dawson, William O

    2010-07-05

    The long flexuous bipolar virions of Citrus tristeza virus (CTV), a Closterovirus, are encapsidated with two capsid proteins at opposite ends: the minor coat protein (CPm) encapsidates the 5' 630 nts of the genomic RNA and the major coat protein encapsidates the remainder of the genome. In this study, we found encapsidation of CTV CPm in the absence of other assembly-related proteins is highly specific in contrast to most plant viruses that allow virion assembly by a range of heterologous coat proteins. Heterologous CPms with 95-96% amino acid identity from related strains in CTV-CPm, a replicon with CPm as the only assembly-related ORF, either failed to initiate encapsidation or reduced encapsidation substantially. Substitution of subsets of amino acids revealed that the amino acids that differ between positions 121 and 180 of the VT strain, and 61 and 120 of the T3 strain were involved in specific encapsidation. We further mapped the specific encapsidation to a single amino acid: mutation of methionine(165) to threonine (VT type) or serine(105) to proline (T3 type) in CTV-CPm failed to form nucleocapsids. However, the heterologous CPm in combination with both HSP70h and p61 proteins, but not HSP70h or p61 alone, encapsidated at wild-type levels, suggesting that specific encapsidation by CPm was mitigated by the combination of HSP70h and p61. Thus, in addition to the previously described functions of HSP70h and p61 of greatly enhanced virion formation and restriction of CPm encapsidation to the 5' 630 nts of the genomic RNA, these proteins facilitate encapsidation by heterologous CPms. Published by Elsevier Inc.

  19. KCl-Induced High-Temperature Corrosion Behavior of HVAF-Sprayed Ni-Based Coatings in Ambient Air

    Science.gov (United States)

    Jafari, Reza; Sadeghimeresht, Esmaeil; Farahani, Taghi Shahrabi; Huhtakangas, Matti; Markocsan, Nicolaie; Joshi, Shrikant

    2018-01-01

    KCl-induced high-temperature corrosion behavior of four HVAF-sprayed Ni-based coatings (Ni21Cr, Ni5Al, Ni21Cr7Al1Y and Ni21Cr9Mo) under KCl deposit has been investigated in ambient air at 600 °C up to 168 h. The coatings were deposited onto 16Mo3 steel—a widely used boiler tube material. Uncoated substrate, 304L and Sanicro 25 were used as reference materials in the test environment. SEM/EDS and XRD techniques were utilized to characterize the as-sprayed and exposed samples. The results showed that the small addition of KCl significantly accelerated degradation to the coatings. All coatings provided better corrosion resistance compared to the reference materials. The alumina-forming Ni5Al coating under KCl deposit was capable of forming a more protective oxide scale compared to the chromia-forming coatings as penetration of Cl through diffusion paths was hindered. Both active corrosion and chromate formation mechanisms were found to be responsible for the corrosion damages. The corrosion resistance of the coatings based on the microstructure analysis and kinetics had the following ranking (from the best to worst): Ni5Al > Ni21Cr > Ni21Cr7Al1Y > Ni21Cr9Mo.

  20. Osteogenesis of adipose-derived stem cells on polycaprolactone-β-tricalcium phosphate scaffold fabricated via selective laser sintering and surface coating with collagen type I.

    Science.gov (United States)

    Liao, Han-Tsung; Lee, Ming-Yih; Tsai, Wen-Wei; Wang, Hsiu-Chen; Lu, Wei-Chieh

    2016-10-01

    The current study aimed to fabricate three-dimensional (3D) polycaprolactone (PCL), polycaprolactone and β-tricalcium phosphate (PCL-TCP) scaffolds via a selective laser-sintering technique (SLS). Collagen type I was further coated onto PCL-TCP scaffolds to form PCL-TCP-COL scaffolds. The physical characters of these three scaffolds were analysed. The osteogenic potential of porcine adipose-derived stem cells (pASCs) was compared among these three scaffolds in order to find an optimal scaffold for bone tissue engineering. The experimental results showed no significant differences in pore size and porosity among the three scaffolds; the porosity was ca. 75-77% and the pore size was ca. 300-500 µm in all three. The compressive modulus was increased from 6.77 ± 0.19 to 13.66 ± 0.19 MPa by adding 30% β-TCP into a 70% PCL scaffold. No significant increase of mechanical strength was found by surface-coating with collagen type I. Hydrophilicity and swelling ratios showed statistical elevation (p < 0.05) after collagen type I was coated onto the PCL-TCP scaffolds. The in vitro study demonstrated that pASCs had the best osteogenic differentiation on PCL-TCP-COL group scaffolds, due to the highest ALP activity, osteocalcin mRNA expression and mineralization. A nude mice experiment showed better woven bone and vascular tissue formation in the PCL-TCP-COL group than in the PCL group. In conclusion, the study demonstrated the ability to fabricate 3D, porous PCL-TCP composite scaffolds (PCL:TCP = 70:30 by weight) via an in-house-built SLS technique. In addition, the osteogenic ability of pASCs was found to be enhanced by coating COL onto the PCL-TCP scaffolds, both in vitro and in vivo. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Propagation of cracks by stress corrosion in conditions of BWR type reactor; Propagacion de grietas por corrosion bajo esfuerzo en condiciones de reactor de agua en ebullicion (BWR)

    Energy Technology Data Exchange (ETDEWEB)

    Merino C, F.J. [ININ, 52045 Estado de Mexico (Mexico); Fuentes C, P. [ITT, Metepec, Estado de Mexico (Mexico)]. E-mail: fjmc@nuclear.inin.mx

    2004-07-01

    In this work, the obtained results when applying the Hydrogen Chemistry to a test tube type Compact Tension (CT), built in austenitic stainless steel 304l, simulating the conditions to those that it operates a Boiling Water Reactor (BWR), temperature 288 C and pressure of 8 MPa are presented. With the application of this water chemistry, seeks to be proven the diminution of the crack propagation speed. (Author)

  2. Culture on a fragmin/protamine-coated plate suppresses the collagen type IαI and TGF-β1 mRNA expression of rat hepatic stellate RI-T cells.

    Science.gov (United States)

    Sekiguchi, Hitomi; Hemmi, Natsuko; Maki, Takehiro; Ozawa, Aisa; Kadowaki, Erina; Kamiie, Junichi; Yamamoto, Masako; Arishima, Kazuyoshi; Sakaue, Motoharu

    2013-01-01

    Hepatic stellate cells (HSCs) intracellularly preserve vitamin A in the normal liver. When the liver is damaged, HSCs transform into myofibroblast-like cells, and then proliferate and increase their expression of collagen. Cultured on a plastic plate, HSCs spontaneously activate. To maintain HSCs in a quiescent state with low expression of collagen, coating methods with extracellular matrixes (ECMs) such as Matrigel-coating or laminin-rich coating are commonly used for HSC cultivation. Kishimoto et al. [14] reported that Fragmin®/protamine microparticles (F/P-MPs) have the ability to absorb heparin-binding cytokines like ECMs. Therefore, we examined whether the cultivation on an F/P-MPs-coated plate maintains the quiescent state of RI-T cells (derived from rat HSCs) including the suppression of collagen expression. We found that the mRNA levels of collagen type IαI and TGF-β1 in RI-T cells were significantly suppressed in the cultivation on F/P-MPs-coated plates compared to cultures on noncoated and Matrigel-coated plates. We conclude that the F/P-MPs coating method is useful for maintaining with low expressions of collagen IαI and TGF-β 1 mRNA levels in HSCs.

  3. Chitosan–Collagen Coated Magnetic Nanoparticles for Lipase Immobilization—New Type of “Enzyme Friendly” Polymer Shell Crosslinking with Squaric Acid

    Directory of Open Access Journals (Sweden)

    Marta Ziegler-Borowska

    2017-01-01

    Full Text Available This article presents a novel route for crosslinking a polysaccharide and polysaccharide/protein shell coated on magnetic nanoparticles (MNPs surface via condensation reaction with squaric acid (SqA. The syntheses of four new types of collagen-, chitosan-, and chitosan–collagen coated magnetic nanoparticles as supports for enzyme immobilization have been done. Structure and morphology of prepared new materials were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR, XRD, and TEM analysis. Next, the immobilization of lipase from Candida rugosa was performed on the nanoparticles surface via N-(3-dimethylaminopropyl-N′-ethylcarbodiimide hydrochloride (EDC/N-hydroxy-succinimide (NHS mechanism. The best results of lipase activity recovery and specific activities were observed for nanoparticles with polymer shell crosslinked via a novel procedure with squaric acid. The specific activity for lipase immobilized on materials crosslinked with SqA (52 U/mg lipase was about 2-fold higher than for enzyme immobilized on MNPs with glutaraldehyde addition (26 U/mg lipase. Moreover, a little hyperactivation of lipase immobilized on nanoparticles with SqA was observed (104% and 112%.

  4. Visualizing tissue molecular structure of a black type of canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way.

    Science.gov (United States)

    Yu, Peiqiang

    2013-02-20

    Heat-related processing of cereal grains, legume seeds, and oil seeds could be used to improve nutrient availability in ruminants. However, different types of processing may have a different impact on intrinsic structure of tissues. To date, there is little research on structure changes after processing within intact tissues. The synchrotron-based molecular imaging technique enables us to detect inherent structure change on a molecular level. The objective of this study was to visualize tissue of black-type canola (Brassica) seed with a thick seed coat after heat-related processing in a chemical way using the synchrotron imaging technique. The results showed that the chemical images of protein amides were obtained through the imaging technique for the raw, wet, and dry heated black type of canola seed tissues. It seems that different types of processing have a different impact on the protein spectral profile in the black type of canola tissues. Wet heating had a greater impact on the protein α-helix to β-sheet ratio than dry heating. Both dry and wet heating resulted in different patterns in amide I, the second derivative, and FSD spectra. However, the exact differences in the tissue images are relatively difficult to be obtained through visual comparison. Future studies should focus on (1) comparing the response and sensitivity of canola seeds to various processing methods between the yellow-type and black-type of canola seeds; (2) developing a sensitive method to compare the image difference between tissues and between treatments; (3) developing a method to link images to nutrient digestion, and (4) revealing how structure changes affect nutrient absorption in humans and animals.

  5. The role of nanocrystalline binder metallic coating into WC after additive manufacturing

    Science.gov (United States)

    Cavaleiro, A. J.; Fernandes, C. M.; Farinha, A. R.; Gestel, C. V.; Jhabvala, J.; Boillat, E.; Senos, A. M. R.; Vieira, M. T.

    2018-01-01

    Tungsten carbide with microsized particle powders are commonly used embedded in a tough binder metal. The application of these composites is not limited to cutting tools, WC based material has been increasingly used in gaskets and other mechanical parts with complex geometries. Consequently, additive manufacturing processes as Selective Laser Sintering (SLS) might be the solution to overcome some of the manufacturing problems. However, the use of SLS leads to resolve the problems resulting from difference of physical properties between tungsten carbide and the metallic binder, such as laser absorbance and thermal conductivity. In this work, an original approach of powder surface modification was considered to prepare WC-metal composite powders and overcome these constraints, consisting on the sputter-coating of the WC particle surfaces with a nanocrystalline thin film of metallic binder material (stainless steel). The coating improves the thermal behavior and rheology of the WC particles and, at the same time, ensures a binder homogenous distribution. The feasibility of the SLS technology as manufacturing process for WC powder sputter-coated with 13 wt% stainless steel AISI 304L was explored with different laser power and scanning speed parameters. The SLS layers were characterized regarding elemental distribution, phase composition and morphology, and the results are discussed emphasizing the role of the coating on the consolidation process.

  6. Measurement of serum type III procollagen aminopeptide with RIA-gnost PIIIP coated tube; Changes in patinets with various alcoholic liver diseases after abstinence

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Katsuya; Takagi, Toshikazu (Kurihama National Hospital, Yokohama, Kanagawa (Japan)); Okazaki, Isao (and others)

    1992-02-01

    In 55 patients with various alcoholic liver diseases, serum type III procollagen aminopeptide (PIIIP) was measured on admission, on biopsy (2-4 weeks after admission) and on discharge from hospital (3 months after admission) using RIA-gnost PIIIP coated tube, an assay kit recently launched by Hoechst Japan Limited. Serum PIIIP on admission showed a good correlation with the degree of hepatic fibrosis and was significantly higher in any disease group than in healthy controls, suggesting its usefulness as an indicator of hepatic fibrosis. After abstinence, however, serum PIIIP level exhibited an increasing tendency in all the disease groups expect alcoholic hepatitis, and the number of laboratory tests showing a significant correlation with PIIIP decreased as compared with that on admission. The mechanism of serum PIIIP elevations seen after abstience is yet to be elucidated in detail, considering their possible association with factors other than collagen synthesis in the liver. (author).

  7. Enhanced migration of murine fibroblast-like 3T3-L1 preadipocytes on type I collagen-coated dish is reversed by silibinin treatment.

    Science.gov (United States)

    Liu, Xiaoling; Xu, Qian; Liu, Weiwei; Yao, Guodong; Zhao, Yeli; Xu, Fanxing; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-Ichi; Onodera, Satoshi; Yamato, Masayuki; Ikejima, Takashi

    2017-09-20

    Migration of fibroblast-like preadipocytes is important for the development of adipose tissue, whereas excessive migration is often responsible for impaired adipose tissue related with obesity and fibrotic diseases. Type I collagen (collagen I) is the most abundant component of extracellular matrix and has been shown to regulate fibroblast migration in vitro, but its role in adipose tissue is not known. Silibinin is a bioactive natural flavonoid with antioxidant and antimetastasis activities. In this study, we found that type I collagen coating promoted the proliferation and migration of murine 3T3-L1 preadipocytes in a dose-dependent manner, implying that collagen I could be an extracellular signal. Regarding the mechanisms of collagen I-stimulated 3T3-L1 migration, we found that NF-κB p65 is activated, including the increased nuclear translocation of NF-κB p65 as well as the upregulation of NF-κB p65 phosphorylation and acetylation, accompanied by the increased expressions of proinflammatory factors and the generation of reactive oxygen species (ROS). Reduction of collagen I-enhanced migration of cells by treatment with silibinin was associated with suppression of NF-κB p65 activity and ROS generation, and negatively correlated with the increasing sirt1 expression. Taken together, the enhanced migration of 3T3-L1 cells induced on collagen I-coated dish is mediated by the activation of NF-κB p65 function and ROS generation that can be alleviated with silibinin by upregulation of sirt1, leading to the repression of NF-κB p65 function and ROS generation.

  8. The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Mamum, Md Abdullah A. [Old Dominion Univ., Norfolk, VA (United States); Elmustafa, Abdelmageed A, [Old Dominion Univ., Norfolk, VA (United States); Stutzman, Marcy L. [JLAB, Newport News, VA (United States); Adderley, Philip A. [JLAB, Newport News, VA (United States); Poelker, Matthew [JLAB, Newport News, VA (United States)

    2014-03-01

    The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

  9. Phased-Array Focusing Potential in Pipe with Viscoelastic Coating

    Science.gov (United States)

    Van Velsor, J. K.; Zhang, L.; Breon, L. J.; Rose, J. L.

    2007-03-01

    This work investigates the effectiveness of traditional guided-wave focusing techniques in piping with viscoelastic coating. Focusing results for an uncoated pipe are compared to that of pipe with a fusion-bonded epoxy coating, a coal-tar mastic coating, a coal-tar epoxy coating, a coal-tar tape coating, a wax coating, and an enamel coating. Experimental results are compared to computationally derived models. Results show that, for most coating types, focusing can be achieved without special consideration of the coating. This is significant in that it demonstrates the immediate applicability of traditional focusing techniques to coated pipeline.

  10. Effects of acid catalyst type on structural, morphological, and optoelectrical properties of spin-coated TiO{sub 2} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Golobostanfard, Mohammad Reza, E-mail: Bostanfr@ut.ac.ir [School of Metallurgy and Materials Engineering, College of engineering, University of Tehran, PO Box: 14395-553, Tehran (Iran, Islamic Republic of); Abdizadeh, Hossein [School of Metallurgy and Materials Engineering, College of engineering, University of Tehran, PO Box: 14395-553, Tehran (Iran, Islamic Republic of)

    2013-03-15

    The effects of different acid catalysts of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, acetic acid, and citric acid on structural, morphological, and optoelectrical properties of nanocrystalline spin-coated TiO{sub 2} thin films synthesized via alkoxide sol–gel route were investigated. It was found that only the sols with HNO{sub 3} and HCl are suitable for film preparation. The X-ray diffractometry and Raman analysis showed that crystalline phases could be controlled by the type of acid catalyst. Although the H{sub 2}SO{sub 4} sol shows good stability, it causes extremely different morphology to form due to its different sol nature and high contact angle. Fourier transformed infrared spectra confirmed the presence of acid anion species in all samples even after calcination. Furthermore, it was inferred from UV–visable absorption spectra that although the band gap and thickness of the films are independent of acid catalyst type, the refractive index and porosity of the films are strongly affected by the type of acids.

  11. Sodium and potassium doped P-type ZnO films by sol-gel spin-coating technique

    Science.gov (United States)

    Au, Benedict Wen-Cheun; Chan, Kah-Yoong

    2017-07-01

    Zinc oxide (ZnO) is a promising material in a variety of applications including sensors, transistors and solar cells. Many researchers studied N-type ZnO films and reported enhanced properties. On the other hand, P-type ZnO films were rarely attempted due to the self-compensation effect. Success in achieving P-type ZnO films is important as it will pave the way for more advanced complementary devices. In this work, P-type sodium and potassium doped ZnO films were fabricated on glass substrates with doping concentration between 0 and 25 at.%. The influences of doping concentration on surface morphology, structural, optical and electrical properties were investigated using atomic force microscopy, X-ray diffraction spectroscopy, energy-dispersive X-ray spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometer, photoluminescence spectroscopy and Hall-effect electrical transport measurement system. The distinctive behavior of P-type ZnO films with different doping concentrations will be discussed.

  12. Wheat streak mosaic virus Coat Protein Deletion Mutants Elicit More Severe Symptoms Than Wild-Type Virus in Multiple Cereal Hosts.

    Science.gov (United States)

    Tatineni, Satyanarayana; Elowsky, Christian; Graybosch, Robert A

    2017-12-01

    Previously, we reported that coat protein (CP) of Wheat streak mosaic virus (WSMV) (genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. In this study, we demonstrated that WSMV mutants with deletion of CP amino acids 58 to 84 but not of 36 to 57 induced severe chlorotic streaks and spots, followed by acute chlorosis in wheat, maize, barley, and rye compared with mild to moderate chlorotic streaks and mosaic symptoms by wild-type virus. Deletion of CP amino acids 58 to 84 from the WSMV genome accelerated cell-to-cell movement, with increased accumulation of genomic RNAs and CP, compared with the wild-type virus. Microscopic examination of wheat tissues infected by green fluorescent protein-tagged mutants revealed that infection by mutants lacking CP amino acids 58 to 84 caused degradation of chloroplasts, resulting in acute macroscopic chlorosis. The profile of CP-specific proteins was altered in wheat infected by mutants causing acute chlorosis, compared with mutants eliciting wild-type symptoms. All deletion mutants accumulated CP-specific major protein similarly to that in wild-type virus; however, mutants that elicit acute chlorosis failed to accumulate a 31-kDa minor protein compared with wild-type virus or mutants lacking amino acids 36 to 57. Taken together, these data suggest that deletion of CP amino acids 58 to 84 from the WSMV genome enhanced accumulation of CP and genomic RNA, altered CP-specific protein profiles, and caused severe symptom phenotypes in multiple cereal hosts.

  13. Optical and magneto-optical properties of spin coated films of novel trinuclear bis(oxamato) and bis(oxamidato) type complexes

    Energy Technology Data Exchange (ETDEWEB)

    Abdulmalic, Mohammad A. [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Straße der Nationen 62, D-09111 Chemnitz (Germany); Fronk, Michael [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Bräuer, Björn [Stanford Institute of Materials and Energy Science, Stanford University, Stanford, CA 94025 (United States); Zahn, Dietrich R.T. [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Salvan, Georgeta, E-mail: salvan@physik.tu-chemnitz.de [Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Physik, Reichenhainer Straße 70, D-09107 Chemnitz (Germany); Eya' ane Meva, Francois [Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, BP 2701 (Cameroon); and others

    2016-12-01

    This work reports the first example of the spectroscopic measurements of the Magneto-Optical Kerr Effect (MOKE) of films being composed of trinuclear transition metal complexes on a non-transparent substrate at room temperature. The thin films of the tailor-made trinuclear bis(oxamidato) type complex 5 ([Cu{sub 3}(opbo{sup n}Pr{sub 2})(tmcd){sub 2}(NO{sub 3}){sub 2}], opbo{sup n}Pr{sub 2} = o-phenylenebis(N’-{sup n}propyloxamido, tmcd=trans-(1 R,2 R)-N,N,N′,N′-tetramethyl-cyclohexanediamine) and of the bis(oxamato) type complexes 11 ([Cu{sub 2}Ni(opbaCF{sub 3})(pmdta){sub 2}(NO{sub 3}){sub 2}], opbaCF{sub 3} = 4-trifluoromethyl-o-phenylenebis(oxamato), pmdta = N,N,N,′N″,N″-pentamethyldiethylenetriamine) and 12 ([Cu{sub 3}(opba)(bppe){sub 2}(NO{sub 3}){sub 2}] (opba = o-phenylenebis(oxamato), bppe = S-N,N-bis(2-picolyl)−1-phenylethylamine) were fabricated by spin-coating and their thicknesses in the range between 0.5 µm and 2 µm was determined by spectroscopic ellipsometry. Based on the spectroscopic ellipsometry results it was also possible to determine the optical constants of the film and compare them with the absorption of the complexes in solution in order to confirm the complex integrity after the film deposition. The fabrication of high-quality films which exhibit Kerr rotation up to 0.2 mrad (11.5 mdeg) was only possible due to tailor-made synthesis, which allows circumventing intermolecular interactions of the trinuclear complexes during the film formation. - Highlights: • Tailor-made trinuclear bis(oxamidato) and bis(oxamato) type complexes were synthesized. • Thin films (between 0.5 µm and 2 µm) were fabricated by spin-coating. • The film optical constants indicate the complex integrity after the deposition. • Film quality enabled first spectroscopic MOKE measurements of multi-nuclear complexes. • Magneto-optical Kerr rotation up to 11.5 mdeg was observed at RT (in 1.7 T).

  14. A photo-assisted microbial electrolysis cell for the exclusive biohydrogen production using a MoS2-coated p-type copper oxide

    Science.gov (United States)

    Jeon, Yongwon; Kim, Jun Hyun; Koo, Kyoungmin; Kim, Sunghyun

    2018-01-01

    A microbial electrolysis cell (MEC) has been regarded as an emerging new technology for the biohydrogen production from various organic substances, even from wastewater. One major problem is, however, that methane dominates produced gases in a long-term operation. Here we report that a photo-assisted MEC (PAMEC) is an efficient way to produce hydrogen with a p-type semiconductor cathode. When Cu2O coated with MoS2 as cocatalyst (MoS2/Cu2O) is employed, only hydrogen with essentially no methane and carbon dioxide was produced from acetate at -0.8 V bias under visible light illumination at a rate of 2.72 m3H2 m-3d-1. No appreciable performance degradation is observed over 50 days of operation. At lower bias voltage, methane and carbon dioxide begins to be produced. Energy efficiency based on input electricity and hydrogen yield are 225% and 3.4, respectively. This excellent feature of PAMEC is attributed to p-type semiconductor characteristics of Cu2O and proton reduction activity of MoS2. Electrons generated from acetate oxidation at the anode are photoexcited to the conduction band at the Cu2O acquiring enough reduction potential to reduce protons. The concept of PAMEC can be extended to wastewater treatment for the hydrogen production.

  15. Comparison of Azelnidipine and Trichlormethiazide in Japanese Type 2 Diabetic Patients with Hypertension: The COAT Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Masahiro Takihata

    Full Text Available This study compared the efficacy and safety of azelnidipine with that of trichlormethiazide in Japanese type 2 diabetic patients with hypertension.In a multicenter, open-label trial, 240 patients with adequately controlled diabetes (HbA1c ≤ 7.0% under lifestyle modification and/or administration of hypoglycemic agents and inadequately controlled hypertension (systolic blood pressure [sBP] ≥ 130 mmHg or diastolic blood pressure [dBP] ≥ 80 mmHg who were being treated with olmesartan were enrolled. Participants were randomly assigned to an azelnidipine group or a trichlormethiazide group and were followed up for 48 weeks. Main outcome measure was the difference in the change in HbA1c levels from the baseline values at 48 weeks between these two groups.Of the 240 subjects that were enrolled, 209 subjects (azelnidipine group: 103 patients, trichlormethiazide group: 106 patients completed this trial. At 48 weeks, the following changes were observed in the azelnidipine and trichlormethiazide groups, respectively: HbA1c levels, 0.19 ± 0.52% and 0.19 ± 0.54%; sBP/dBP, -10.7 ± 9.6/-6.6 ± 6.6 mmHg and -7.1 ± 7.7/-3.3 ± 6.1 mmHg (P < 0.001 for both sBP and dBP. In both groups, dizziness (12 patients [11.7%] and 16 patients [15.1%] and edema (16 patients [15.5%] and 7 patients [6.6%], P = 0.047 were observed during the 48-week follow-up period.Azelnidipine was more effective for controlling blood pressure than trichlormethiazide in Japanese type 2 diabetes patients, whereas trichlormethiazide was more effective for reducing albuminuria than azelnidipine. Both of these agents, however, similarly exacerbated glycemic control in type 2 diabetic patients with hypertension.UMIN 000006081.

  16. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding

    Directory of Open Access Journals (Sweden)

    Hongxia Wan

    2017-04-01

    Full Text Available Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM, atomic force microscopy (AFM, contact angle measurements, Fourier transform infrared spectroscopy (FTIR, and secondary ion mass spectrometry (SIMS. Early heterogeneous swelling at the metal-coating interface in non-defective coated metals was elucidated using frequency-dependent alternating-current scanning electrochemical microscopy. Two types of coatings (styrene-acrylic coating and terpolymer coating were compared. The effects of thickness, surface roughness, and chemical bonding on cathodic delamination were investigated.

  17. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding.

    Science.gov (United States)

    Wan, Hongxia; Song, Dongdong; Li, Xiaogang; Zhang, Dawei; Gao, Jin; Du, Cuiwei

    2017-04-09

    Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and secondary ion mass spectrometry (SIMS). Early heterogeneous swelling at the metal-coating interface in non-defective coated metals was elucidated using frequency-dependent alternating-current scanning electrochemical microscopy. Two types of coatings (styrene-acrylic coating and terpolymer coating) were compared. The effects of thickness, surface roughness, and chemical bonding on cathodic delamination were investigated.

  18. Unique electrophysiological and impedance signatures between encapsulation types: An analysis of biological Utah array failure and benefit of a biomimetic coating in a rat model.

    Science.gov (United States)

    Cody, Patrick A; Eles, James R; Lagenaur, Carl F; Kozai, Takashi D Y; Cui, X Tracy

    2018-04-01

    Intracortical microelectrode arrays, especially the Utah array, remain the most common choice for obtaining high dimensional recordings of spiking neural activity for brain computer interface and basic neuroscience research. Despite the widespread use and established design, mechanical, material and biological challenges persist that contribute to a steady decline in recording performance (as evidenced by both diminished signal amplitude and recorded cell population over time) or outright array failure. Device implantation injury causes acute cell death and activation of inflammatory microglia and astrocytes that leads to a chronic neurodegeneration and inflammatory glial aggregation around the electrode shanks and often times fibrous tissue growth above the pia along the bed of the array within the meninges. This multifaceted deleterious cascade can result in substantial variability in performance even under the same experimental conditions. We track both impedance signatures and electrophysiological performance of 4 × 4 floating microelectrode Utah arrays implanted in the primary monocular visual cortex (V1m) of Long-Evans rats over a 12-week period. We employ a repeatable visual stimulation method to compare signal-to-noise ratio as well as single- and multi-unit yield from weekly recordings. To explain signal variability with biological response, we compare arrays categorized as either Type 1, partial fibrous encapsulation, or Type 2, complete fibrous encapsulation and demonstrate performance and impedance signatures unique to encapsulation type. We additionally assess benefits of a biomolecule coating intended to minimize distance to recordable units and observe a temporary improvement on multi-unit recording yield and single-unit amplitude. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Failure Mechanisms of the Coating/Metal Interface in Waterborne Coatings: The Effect of Bonding

    OpenAIRE

    Hongxia Wan; Dongdong Song; Xiaogang Li; Dawei Zhang; Jin Gao; Cuiwei Du

    2017-01-01

    Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and s...

  20. Contribution à la modélisation du soudage TIG des tôles minces d'acier austénitique 304L par un modèle source bi-elliptique, avec confrontation expérimentale

    Science.gov (United States)

    Aissani, M.; Maza, H.; Belkessa, B.; Maamache, B.

    2005-05-01

    Ce travail contribue dans la modélisation du phénomène du soudage de l'acier inoxydable Austénitique 304L, afin d'étudier le comportement thermique d'un joint de soudure, obtenu par le procédé de soudage à l'arc électrique TIG (Tungsten-Inert-Gas). Le modèle simulant la source d'énergie de soudage, utilise une distribution surfacique Gaussienne du flux de chaleur provenant de l'arc électrique. La forme de cette source est supposée circulaire pour un premier cas et de forme bi-elliptique pour un second cas, tout en procédant à l'évaluation des champs et cycles thermiques à chaque instant, pour déterminer l'étendu des zones à risque, et l'effet de la vitesse de soudage sur ces dernières. Permettant ainsi de remonter par la suite, aux problèmes de contraintes résiduelles et déformations générées dans l'assemblage soudé. L'équation de chaleur régissant le problème est discrétisée par la méthode des volumes finis. Les calculs sont effectués en considérant que les propriétés physiques et thermiques ainsi que les conditions aux limites de convection et rayonnement, sont dépendante de la température. Pour évaluer la précision du modèle, une comparaison avec des mesures expérimentales de température d'un essai de soudage a été effectuée, les résultats indiquent un bon accord.

  1. Antibacterial silver nanocluster/silica composite coatings on stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, M.; Perero, S. [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Ferraris, S., E-mail: sara.ferraris@polito.it [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Miola, M.; Vernè, E. [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Skoglund, S. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden); Blomberg, E. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden); SP Technical Research Institute of Sweden, Chemistry, Materials and Surfaces, P.O. Box 5607, SE-114 86 Stockholm (Sweden); Odnevall Wallinder, I. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden)

    2017-02-28

    Highlights: • A silver nanocluster-silica composite coating sputter-deposited onto stainless steel. • Good adhesion and resistance upon cleaning with NaOH, H{sub 2}SO{sub 4} and detergents. • Low release of silver ions and no release as silver nanoparticles. • Good antibacterial activity against S. aureus even after heating to 450 °C. • Good antibacterial activity shown during cheese production. - Abstract: A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel

  2. Genetic architecture of complex traits and accuracy of genomic prediction: coat colour, milk-fat percentage, and type in Holstein cattle as contrasting model traits.

    Directory of Open Access Journals (Sweden)

    Ben J Hayes

    2010-09-01

    Full Text Available Prediction of genetic merit using dense SNP genotypes can be used for estimation of breeding values for selection of livestock, crops, and forage species; for prediction of disease risk; and for forensics. The accuracy of these genomic predictions depends in part on the genetic architecture of the trait, in particular number of loci affecting the trait and distribution of their effects. Here we investigate the difference among three traits in distribution of effects and the consequences for the accuracy of genomic predictions. Proportion of black coat colour in Holstein cattle was used as one model complex trait. Three loci, KIT, MITF, and a locus on chromosome 8, together explain 24% of the variation of proportion of black. However, a surprisingly large number of loci of small effect are necessary to capture the remaining variation. A second trait, fat concentration in milk, had one locus of large effect and a host of loci with very small effects. Both these distributions of effects were in contrast to that for a third trait, an index of scores for a number of aspects of cow confirmation ("overall type", which had only loci of small effect. The differences in distribution of effects among the three traits were quantified by estimating the distribution of variance explained by chromosome segments containing 50 SNPs. This approach was taken to account for the imperfect linkage disequilibrium between the SNPs and the QTL affecting the traits. We also show that the accuracy of predicting genetic values is higher for traits with a proportion of large effects (proportion black and fat percentage than for a trait with no loci of large effect (overall type, provided the method of analysis takes advantage of the distribution of loci effects.

  3. Thermal stability of phosphate coatings on steel

    OpenAIRE

    P. Pokorny; P. Szelag; Novak, M; L. Mastny; Brozek, V.

    2015-01-01

    The work was validated thermal stability of zinc, manganese and tri-cations phosphate coatings on steel, made from commercial phosphating bath type Pragofos. Thermogravimetric data dehydration of scholzite, phosphophylite and hureaulite coatings in the temperature range 160 °C – 400 °C define the conditions for applying paints with higher firing temperature or thermal spraying ceramic coatings.

  4. Thermal stability of phosphate coatings on steel

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2015-07-01

    Full Text Available The work was validated thermal stability of zinc, manganese and tri-cations phosphate coatings on steel, made from commercial phosphating bath type Pragofos. Thermogravimetric data dehydration of scholzite, phosphophylite and hureaulite coatings in the temperature range 160 °C – 400 °C define the conditions for applying paints with higher firing temperature or thermal spraying ceramic coatings.

  5. A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO.

    Science.gov (United States)

    Naya, Shin-ichi; Kume, Takahiro; Okumura, Nozomi; Tada, Hiroaki

    2015-07-21

    The principal purpose of this study is to present a new design for preparing highly active immobilized gold nanoparticle-based plasmonic photocatalysts. Gold nanoparticles were loaded on rutile TiO2 particles with a mean size of 80 nm (Au/TiO2) by the deposition precipitation method. The surface of SnO2 particles with a mean size of 100 nm was modified by copper(ii) oxide clusters (CuO/SnO2) with the loading amount (Γ/Cu ions nm(-2)) precisely controlled by the chemisorption-calcination cycle technique. Two mesoporous overlayers of Au/TiO2 and CuO/SnO2 were coated side by side on glass substrates with a fluorine-doped tin oxide film (FTO) using the doctor blade method (Au/mp-TiO2|FTO|CuO/mp-SnO2). As test reactions for assessing the visible-light activity, we carried out gas-phase decomposition of acetaldehyde and liquid-phase oxidation of alcohol. In each reaction, this bi-overlayer type catalyst shows a high level of visible-light activity much exceeding those of Au/TiO2 particles and a Au/mp-TiO2|FTO mono-overlayer type catalyst [J. Phys. Chem. C, 2014, 118, 26887]. To confirm the origin of the striking visible-light activity, we studied the electrocatalytic activity of CuO/mp-SnO2|FTO electrodes for the oxygen reduction reaction (ORR). Both the visible-light activity of Au/mp-TiO2|FTO|CuO/mp-SnO2 and the electrocatalytic activity of CuO/mp-SnO2|FTO for ORR strongly depend on the Γ value. A good positive correlation has been found between the visible-light activities and the electrocatalytic activity for ORR. The striking activity of the present bi-overlayer type catalyst can be attributed to the efficient and long-range charge separation by the vectorial electron transport (Au(oxidation sites) → TiO2→ FTO, SnO2→ CuO(reduction sites)) and the excellent electrocatalytic activity of the CuO clusters.

  6. Compositional, morphological and mechanical investigations of monolayer type coatings obtained by standard and reactive magnetron sputtering from Ti, TiB{sub 2} and WC

    Energy Technology Data Exchange (ETDEWEB)

    Jinga, V., E-mail: jingavlad@yahoo.com [Transilvania University of Braşov, Faculty of Materials Science and Engineering, Department of Materials Science, 1 Colina Universităţii, 500068 Braşov (Romania); Mateescu, A.O. [Transilvania University of Braşov, Faculty of Materials Science and Engineering, Department of Materials Science, 1 Colina Universităţii, 500068 Braşov (Romania); Horia Hulubei National Institute of Physics and Nuclear Engineering, 30 Reactorului Street, 077125 Măgurele, Ilfov District (Romania); Cristea, D. [Transilvania University of Braşov, Faculty of Materials Science and Engineering, Department of Materials Science, 1 Colina Universităţii, 500068 Braşov (Romania); Mateescu, G.; Burducea, I.; Ionescu, C.; Crăciun, L.S. [Horia Hulubei National Institute of Physics and Nuclear Engineering, 30 Reactorului Street, 077125 Măgurele, Ilfov District (Romania); Ghiuţă, I.; Samoilă, C. [Transilvania University of Braşov, Faculty of Materials Science and Engineering, Department of Materials Science, 1 Colina Universităţii, 500068 Braşov (Romania); and others

    2015-12-15

    Highlights: • Thin films have been obtained by simultaneous sputtering from Ti, TiB{sub 2}, and WC targets. • The films are nonstoichiometric, with hardness values between 20 and 22 GPa. • The friction coefficients for the (film – 100Cr6 steel) system are 0.18 and 0.23. • The films show promising wear resistance, if paired with appropriate substrates. - Abstract: The purpose of this work was to study new composite coatings that would have wear resistant properties. The coatings were obtained by standard and reactive simultaneous magnetron sputtering from three targets (Ti, TiB{sub 2}, WC) with or without N{sub 2} as reactive gas. The chemical composition of the coatings was investigated by Rutherford backscattering spectrometry, while the morphological features were evaluated by atomic force microscopy. Some of the mechanical properties of the coatings, such as hardness and Young's modulus, were investigated by nanoindentation, while the adherence to the substrate was investigated by scratch tests. The wear resistance and friction coefficients were evaluated using a pin-on-disk tribometer. The films are hard (H{sub it} between 20 and 22 GPa) and show promising results concerning their wear resistance, especially if the films would be paired with an appropriate substrate material.

  7. Research progress of nano self - cleaning anti-fouling coatings

    Science.gov (United States)

    Liu, Y.; Zhao, Y. J.; Teng, J. L.; Wang, J. H.; Wu, L. S.; Zheng, Y. L.

    2018-01-01

    There are many methods of evaluating the performance of nano self-cleaning anti-fouling coatings, such as carbon blacking method, coating reflection coefficient method, glass microbead method, film method, contact angle and rolling angle method, organic degradation method, and the application of performance evaluation method in self-cleaning antifouling coating. For the more, the types of nano self-cleaning anti-fouling coatings based on aqueous media was described, such as photocatalytic self-cleaning coatings, silicone coatings, organic fluorine coatings, fluorosilicone coatings, fluorocarbon coatings, polysilazane self-cleaning coatings. The research and application of different kinds of nano self-cleaning antifouling coatings are anlysised, and the latest research results are summed.

  8. Evaluation of Manganese Phosphate Coatings.

    Science.gov (United States)

    1984-02-01

    D-AiD9 434 EVALUATION OF MANGANESE PHOSPHATE COTINGS(I) ARMY v/1 ARMAMENT RESEARCH R D DEVELO MENT CENTER IdATERYL lET NY I LARGE CALIBER WEAPON...5Y IIARS 163 TECHNICAL REPORT ARLCB-TR- 64003 EVALUATION OF MANGANESE PHOSPHATE COATINGS R. A. FARRARA FEBRUARY 1984 N US ARMY ARMAMENT RESEARCH AND...84003 _____________ 4. TTLE and -bitle)5. TYPE OF REPORT & PERIOD COVERED EVALUATION OF MANGANESE PHOSPHATE COATINGS Final 6. PERFORMING ORG. REPORT

  9. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Intense UV photoluminescence is observed for intrinsic ZnO film. Keywords : thin films, oxidize zinc doped aluminium (ZnO:Al), sol-gel, spin coating, structural analysis, electric and optical properties. 1. Introduction. Depuis ces vingt dernières années les couches minces d'oxyde de zinc ont connu un intérêt croissant dans ...

  10. Standard practice for characterization of coatings using conformable Eddy-Current sensors without coating reference standards

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This practice covers the use of conformable eddy-current sensors for nondestructive characterization of coatings without standardization on coated reference parts. It includes the following: (1) thickness measurement of a conductive coating on a conductive substrate, (2) detection and characterization of local regions of increased porosity of a conductive coating, and (3) measurement of thickness for nonconductive coatings on a conductive substrate or on a conductive coating. This practice includes only nonmagnetic coatings on either magnetic (μ ≠ μ0) or nonmagnetic (μ = μ0) substrates. This practice can also be used to measure the effective thickness of a process-affected zone (for example, shot peened layer for aluminum alloys, alpha case for titanium alloys). For specific types of coated parts, the user may need a more specific procedure tailored to a specific application.

  11. Culturing in serum-free culture medium on collagen type-I-coated plate increases expression of CD133 and retains original phenotype of HT-29 cancer stem cell.

    Science.gov (United States)

    Arab-Bafrani, Zahra; Shahbazi-Gahrouei, Daryoush; Abbasian, Mehdi; Saberi, Alihossein; Fesharaki, Mehrafarin; Hejazi, Seyed Hossein; Manshaee, Samira

    2016-01-01

    A sub-population of tumor cells termed cancer stem cells (CSCs) has an important role in tumor initiation, progression, and recurrence. Selecting a suitable procedure for isolation and enrichment of CSCs is the biggest challenge in the study of CSCs. In the present study, the role of the combination of stem cell culture medium and collagen type-I was evaluated for successful isolation and enrichment of HT-29 CSCs. HT-29 cells were cultured in serum-containing medium (parental culture medium: Medium + 10% fetal bovine serum) and serum-free medium (stem cell culture medium); both on collagen-coated plates. Spheres forming ability and CD133 expression, as a potential marker of colorectal CSCs, were evaluated in two culture mediums. The results show spheroids usually give rise completely within 15 days in the stem cell culture medium on the collagen-coated plate. CD133 expression in spheroid cells (84%) is extensively higher than in parental cells (25%). Moreover, relative to parental cells, spheroid cells were more radioresistance. Finding of this study suggested that CSCs derived from colon cancer cell line (HT-29) can be propagated and form colonospheres in serum-free culture medium on collagen type-I. According to maintenance of their original phenotype in these conditions, it seems serum-free culture medium on collagen type-I is a suitable way to drug screening of HT-29 CSCs.

  12. Efeito do tipo de revestimento na soldagem a ponto de aços galvanizados Effect of coating type on spot welding of galvanized steel

    Directory of Open Access Journals (Sweden)

    Tarcélio Anício da Silva

    2010-09-01

    Full Text Available Os aços galvanizados são cada vez mais utilizados pela indústria automobilística devido à sua excelente resistência à corrosão e boa trabalhabilidade. A soldagem a pontos por resistência de aços galvanizados apresenta o inconveniente de um maior desgaste dos eletrodos quando comparada com a soldagem de aços não revestidos. Este é causado pela reação do zinco com o cobre do eletrodo, formando uma liga Zn-Cu (latão que diminui a vida útil do eletrodo. No presente trabalho, foram feitos testes de soldagem a ponto utilizando aços livres de intersticiais (IF, revestidos por imersão a quente com zinco puro (GI e liga Zn-Fe (GA. Foram determinados os campos de soldabilidade dinâmicos e a vida útil dos eletrodos para juntas formadas pelas combinações GA/GA, GI/GI e GA/GI. O estudo do campo de soldabilidade dinâmica mostrou que os valores de corrente necessários para a obtenção de uma solda adequada aumentam mais rapidamente para a junta de materiais GI/GI e este efeito foi associado com a maior contaminação do eletrodo pelo Zn do revestimento. Por sua vez, a soldagem da junta GA/GI apresenta taxas de variação desta corrente um pouco maiores do que a da junta GA/GA, mas menores que a da junta GI/GI. Em geral, a junta GA/GI apresentou resultados nos testes de soldagem mais próximos dos da junta GA/GA em comparação com os testes com a junta GI/GI. Isto mostra a influência positiva, do revestimento GA, no aumento do número de pontos de solda, mesmo quando a junta é constituída de aços com dois tipos de revestimentos diferentes (GA e GI.Steels coated with zinc and zinc-iron alloys are being increasingly used by the car industry due to their excellent corrosion resistance and good workability. Spot welding of coated steels has the disadvantage of increasing electrodes wear when compared to uncoated steels. Such wear is caused by the reaction of the zinc coating with the copper of the electrode forming an alloy Zn

  13. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Dans ce travail nous avons préparé des couches minces de l'oxyde de zinc ZnO dopées à l'aluminium et non dopées par la technique Sol-Gel associée au « spin coating » sur des substrats en verre « pyrex » à partir de l'acétate de zinc dissous dans une solution de l'éthanol. Nous avons ensuite effectué des analyses ...

  14. Impact of coated windows on visual perception

    DEFF Research Database (Denmark)

    Johnsen, Kjeld; Dubois, Marie-Claude

    of a pilot study that investigated the impact of six coated glazings on daylight conditions in scale models. The study focused primarily on visual perception. Generally, the pilot study indicated that some types of coated glazings (especially solar protective coatings) significantly affect the perception...... of brightness and other visual aspects such as sharpness, details, character, etc., seem to be a complex function of the intensity and colour of the transmitted light and is not solely and linearly dependent on the glazing light transmittance....

  15. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  16. Confectionery coating with an electrohydrodynamic (EHD) system.

    Science.gov (United States)

    Marthina, Kumala; Barringer, Sheryl A

    2012-01-01

    In the confectionery coating industry, hard butters are frequently used as cocoa butter replacers. An electrohydrodynamic (EHD) system, which forms fine droplets with a relatively narrow size distribution, may be beneficial in confectionery coating to produce more even coverage. The objective of this study was to determine the effect of lecithin content and fat type on electrical resistivity and apparent viscosity, and the effect of these variables under EHD (25kV) and non-EHD coating on droplet size, width of coating area, thickness, and minimum flow rate to produce complete coverage. Total of 3 different types of fat were used: cocoa butter, cocoa butter equivalent, and lauric butter. As lecithin content increased, resistivity and apparent viscosity decreased, except all samples showed a local apparent viscosity minimum at 0.5% lecithin. EHD coating was more efficient than non-EHD as a smaller droplet size and thinner coating was formed. Due to repulsive forces between the like-charges on the droplets during EHD, it spread over wider areas which lead to a higher minimum flow rate to get complete coverage. Under EHD, increasing resistivity significantly increased the droplet size, but only at the highest resistivities. There was no correlation between resistivity and droplet size or width of coating under non-EHD. The width of coating under EHD decreased significantly as resistivity increased. Thickness and minimum flow rate to produce complete coverage, significantly correlated to resistivity, for EHD coating, and to apparent viscosity, for 2 of the 3 fat types during both EHD and non-EHD. Electrohydrodynamic (EHD) spraying offers great potential improvement to the food industry especially in the confectionery area. From the quality point of view, EHD offers greater and more complete coverage than non-EHD coating. From the economic point of view, lower cost can be achieved for coated food because during EHD, smaller droplet size and thinner coating is produced.

  17. for zeolite coating

    Directory of Open Access Journals (Sweden)

    Carlos Renato Rambo

    2006-01-01

    Full Text Available Biotemplating is the processing of microcellular ceramics by reproduction of natural morphologies, where the microstructural features of the biotemplate are maintained in the biomorphic ceramic. Different biotemplates with distinct pore anatomies were used to produce biomorphic supports for the zeolite coating: wood, cardboard, sea-sponge and sisal. The biomorphic ceramics were produced by distinguished processing routes: Al-gas infiltration-reaction, liquid-metal infiltration, dip-coating and sol-gel synthesis, in order to produce nitrides, carbides and oxides, depending on the processing conditions. The zeolite coating was performed by hydrothermal growth of MFI-type (Silicalite-1 and ZSM-5 zeolite crystals onto the internal pore walls of the biomorphic templates. The final biomorphic ceramic-zeolite composites were physically characterized, evaluated in terms of their gas adsorption capabilities and correlated to their microstructure and specific pore anatomy. The combination of the properties of the biomorphic ceramics with the adsorption properties of zeolites results in materials with distinct properties as potential candidates for adsorption and catalytic applications due to their characteristic porosity, molecular sieving capabilities and high thermo-mechanical strength.

  18. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... graphene can effectively protect Ni in harsh environments, even after long term exposure. This is made possible by the presence of a high number of graphene layers, which can efficiently mask the cracks and domain boundaries defects found in individual layers of graphene. Our findings thus show...

  19. Mechanical characterization of enamel coated steel bars.

    Science.gov (United States)

    2012-12-01

    In this study, the corrosion process of enamel-coated deformed rebar completely immersed in 3.5 wt.% NaCl solution was evaluated : over a period of 84 days by EIS testing. Three types of enamel coating were investigated: pure enamel, 50/50 enamel coa...

  20. Electrocurtain coating process for coating solar mirrors

    Science.gov (United States)

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  1. Evaluating the impacts of membrane type, coating, fouling, chemical properties and water chemistry on reverse osmosis rejection of seven nitrosoalklyamines, including NDMA.

    Science.gov (United States)

    Steinle-Darling, Eva; Zedda, Marco; Plumlee, Megan H; Ridgway, Harry F; Reinhard, Martin

    2007-09-01

    Reverse osmosis (RO) treatment has been found to be effective for a wide range of organics but generally small, polar, uncharged molecules such as N-nitrosodimethylamine (NDMA) can be poorly rejected. The rejection of seven N-nitrosoalkylamines with molecular masses in the range of 78-158Da, including NDMA, N-nitrosodiethylamine (NDEA), N-nitrosomethylethylamine (NMEA), N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip) by three commercial brackish-water reverse osmosis membranes was studied in flat-sheet cells under cross-flow conditions. The membranes used were ESPA3 (Hydranautics), LFC3 (Hydranautics) and BW-30 (Dow/Filmtec), commonly used in water reuse applications. The effects of varying ionic strength and pH, dip-coating membranes with PEBAX 1657, a hydrophilic polymer, and artificial fouling with alginate on nitrosamine rejection were quantified. Rejection in deionized (DI) water increased with molecular mass from 56 to 70% for NDMA, to 80-91% for NMEA, 89-97% for NPyr, 92-98% for NDEA, and to beyond the detection limits for NPip, NDPA and NDBA. For the nitrosamines with quantifiable transmission, linear correlations (r(2)>0.97) were found between the number of methyl groups and the log(transmission), with factor 0.35 to 0.55 decreases in transmission per added methyl group. A PEBAX coating lowered the ESPA3 rejection of NDMA by 11% but increased the LFC3 and BW30 rejection by 6% and 15%, respectively. Artificially fouling ESPA3 membrane coupons with 170g/m(2) alginate decreased the rejection of NDMA by 18%. A feed concentration of 100mM NaCl decreased rejection of NDMA by 15% and acidifying the DI water feed to pH=3 decreased the rejection by 5%, whereas increasing the pH to 10 did not have a significant (p<0.05) effect.

  2. Ceramic thermal barrier coatings for electric utility gas turbine engines

    Science.gov (United States)

    Miller, R. A.

    1986-01-01

    Research and development into thermal barrier coatings for electric utility gas turbine engines is reviewed critically. The type of coating systems developed for aircraft applications are found to be preferred for clear fuel electric utility applications. These coating systems consists of a layer of plasma sprayed zirconia-yttria ceramic over a layer of MCrAly bond coat. They are not recommended for use when molten salts are presented. Efforts to understand coating degradation in dirty environments and to develop corrosion resistant thermal barrier coatings are discussed.

  3. Nanostructured glass–ceramic coatings for orthopaedic applications

    Science.gov (United States)

    Wang, Guocheng; Lu, Zufu; Liu, Xuanyong; Zhou, Xiaming; Ding, Chuanxian; Zreiqat, Hala

    2011-01-01

    Glass–ceramics have attracted much attention in the biomedical field, as they provide great possibilities to manipulate their properties by post-treatments, including strength, degradation rate and coefficient of thermal expansion. In this work, hardystonite (HT; Ca2ZnSi2O7) and sphene (SP; CaTiSiO5) glass–ceramic coatings with nanostructures were prepared by a plasma spray technique using conventional powders. The bonding strength and Vickers hardness for HT and SP coatings are higher than the reported values for plasma-sprayed hydroxyapatite coatings. Both types of coatings release bioactive calcium (Ca) and silicon (Si) ions into the surrounding environment. Mineralization test in cell-free culture medium showed that many mushroom-like Ca and phosphorus compounds formed on the HT coatings after 5 h, suggesting its high acellular mineralization ability. Primary human osteoblasts attach, spread and proliferate well on both types of coatings. Higher proliferation rate was observed on the HT coatings compared with the SP coatings and uncoated Ti-6Al-4V alloy, probably due to the zinc ions released from the HT coatings. Higher expression levels of Runx2, osteopontin and type I collagen were observed on both types of coatings compared with Ti-6Al-4V alloy, possibly due to the Ca and Si released from the coatings. Results of this study point to the potential use of HT and SP coatings for orthopaedic applications. PMID:21292725

  4. Kinetic analysis of the blood clearance and organ uptake curves of IgG-coated red cells in HLA-typed controls and patients with Wegener's granulomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Woude, F.J. van der; Hauw The, T.; Beekhuis, H.; Beelen, J.M.

    1986-07-01

    Reticuloendothelial function and HLA type were studied in 22 controls and 15 patients with Wegener's granulomatosis (WG). IgG-coated red cells were injected intravenously and half-life of blood disappearance and liver spleen uptake curves were related to the degree of antibody coating. Erythrocytes with 13,990 molecules of IgG per cell gave biexponential blood disappearance curves and were suitable for measuring splenic reticuloendothelial function. Half-life times thus obtained were not significantly different for individuals with the HLA-DR2 or DR3 phenotype. In WG patients with major disease activity, blood clearance of the injected cells was considerably decreased. Kinetic analysis of blood disappearance and spleen uptake curves revealed that this was partly due to a decrease in reversible trapping of the cells in the spleen. This suggests that a blocking effect of circulating immune complexes on splenic Fc receptors is not likely to be the sole cause of the observed hyposplenism.

  5. Conduit Coating Abrasion Testing

    Science.gov (United States)

    Sullivan, Mary K.

    2013-01-01

    During my summer internship at NASA I have been working alongside the team members of the RESTORE project. Engineers working on the RESTORE project are creating ·a device that can go into space and service satellites that no longer work due to gas shortage or other technical difficulties. In order to complete the task of refueling the satellite a hose needs to be used and covered with a material that can withstand effects of space. The conduit coating abrasion test will help the researchers figure out what type of thermal coating to use on the hose that will be refueling the satellites. The objective of the project is to determine whether or not the conduit coating will withstand the effects of space. For the RESTORE project I will help with various aspects of the testing that needed to be done in order to determine which type of conduit should be used for refueling the satellite. During my time on the project I will be assisting with wiring a relay board that connected to the test set up by soldering, configuring wires and testing for continuity. Prior to the testing I will work on creating the testing site and help write the procedure for the test. The testing will take place over a span of two weeks and lead to an informative conclusion. Working alongside various RESTORE team members I will assist with the project's documentation and records. All in all, throughout my internship at NASA I hope to learn a number of valuable skills and be a part of a hard working team of engineers.

  6. Corrosion-Protection Coatings for Aluminum

    Science.gov (United States)

    Higgins, R. H.

    1983-01-01

    Study investigates 21 combinatios of surface treatments, primers and topcoats. Study considers several types of coatings, including primers, enamels, chlorinated rubbers, alkyds, epoxies, vinyls, polyurethanes, waterbased paints, and antifouling paints. 20-page report summarizes the study.

  7. Spectroscopic ellipsometry characterization of coatings on biaxially anisotropic polymeric substrates

    Science.gov (United States)

    Hilfiker, James N.; Pietz, Brandon; Dodge, Bill; Sun, Jianing; Hong, Nina; Schoeche, Stefan

    2017-11-01

    Spectroscopic ellipsometry characterization of coatings on polymeric substrates can be challenging due to the substrate optical anisotropy. We compare four characterization strategies for thin coating layers on anisotropic polymeric substrates with regard to accuracy of the resulting layer thickness and coating optical constants. Each strategy differs in measured data type, model construction, implementation complexity, and inherent capabilities and sensitivity to the coating properties. Best practices and limitations are discussed for each strategy.

  8. Polyester based hybrid organic coatings

    Science.gov (United States)

    Wang, Xiaojiang

    Polyesters are a class of polymers widely used in organic coatings applications. In this work, four types of organic coatings based on polyester polyols were prepared: UV-curable polyester/poly(meth)acrylate coatings, thermal curable polyester polyurethane-urea coatings, thermal curable non-isocyanate polyurethane coatings, and UV-curable non-isocyanate polyurethane coatings. Polyester/poly(meth)acrylate block copolymers are synthesized using a combination of polycondensation and Atom-Transfer Radical Polymerization (ATRP). All block copolymers are characterized by means of Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). In the case of unsaturated-polyester-based block copolymers the main chain double bond in the polyester backbone remains almost unaffected during ATRP. The unsaturated block copolymers are crosslinkable and can form networks upon photo-irradiation in the presence of a suitable photoinitiator. These copolymers might be interesting candidates for coatings with better overall properties than those based on neat polyesters. Thermal curable polyester polyol based Polyurethane-Urea (PUU) coatings were formulated using Partially Blocked HDI isocyanurate (PBH), Isophorone Diamine (IPDA), and polyester polyol. As a comparison, the polyurethane coatings (PU) without adding IPDA were also prepared. The mechanical and viscoelastic properties of the PUU and PU coating were investigated by using tensile test and Dynamic Mechanical Thermal Analyzer (DMTA). It was found that PUU coating exhibited higher crosslink density, Tg, tensile modulus and strength than the corresponding PU coating. Thermal curable non-isocyanate polyurethane coatings were prepared by using polyamine and cyclic carbonate terminated polyester. Cyclic carbonate terminated polyester was synthesized from the reaction of the carbon dioxide and epoxidized polyester which was prepared from the polyester polyol. The properties of the epoxidized and cyclic carbonate

  9. Transient expression of Human papillomavirus type 16 L2 epitope fused to N- and C-terminus of coat protein of Potato virus X in plants.

    Science.gov (United States)

    Cerovska, Noemi; Hoffmeisterova, Hana; Moravec, Tomas; Plchova, Helena; Folwarczna, Jitka; Synkova, Helena; Ryslava, Helena; Ludvikova, Viera; Smahel, Michal

    2012-03-01

    Transient expression of foreign genes based on plant viral vectors is a suitable system for the production of relevant immunogens that can be used for the development of a new generation of vaccines against a variety of infectious diseases. In the present study the epitope derived from HPV-16 L2 minor capsid protein (amino acids 108-120) was expressed from Potato virus X (PVX)-based vector pGR106 as N- or C-terminal fusion with the PVX coat protein (PVX CP) in transgenic Nicotiana benthamiana plants. The fusion protein L2 108-120-PVX CP was successfully expressed in plants at a level of 170 mg/kg of fresh leaf tissue. The C-terminal fusion protein PVX CP- L2 108-120 was expressed using mutated vector sequence to avoid homologous recombination at a level of 8 mg/kg of fresh leaf tissue. Immunogenicity of L2 108-120-PVX CP virus-like particles was tested after immunization of mice by subcutaneous injection or tattoo administration. In animal sera the antibodies against the PVX CP and the L2 108-120 epitope were found after both methods of vaccine delivery.

  10. [The influence of the spectrum and the type of exposure on the contrast of double-sided coated x-ray film].

    Science.gov (United States)

    Blendl, C; Bollen, R; Freytag, K H

    1992-11-01

    The present article describes the circumstances concerning the use of testing aids such as sensitometers with one-sided exposure. It is shown which phenomena must be considered if radiographic films coated on both sides are exposed with a) standard pocket sensitometers (one-sided exposure), b) lab sensitometers (double-sided exposure to ANSI Ph 2.9 [1964]), c) x-radiation in the cassette, intensifying screen and film system (to DIN 6867 T 1). The effect of the emission spectrum on the resulting contrast factor is described. The importance of different emulsion technologies (e.g. orthochromatic anticross-over films) for the contrast factor with one-sided exposure is described. The cross-over factor (c.o.), the apparent variation in sensitivity of the front and back emulsion with one-sided exposure, is the cause of the reduction in the contrast factor (G average) as against double-sided exposure: delta G(%) = c.o.2 x 10(3)/8.4

  11. Flow coating apparatus and method of coating

    Science.gov (United States)

    Hanumanthu, Ramasubrahmaniam; Neyman, Patrick; MacDonald, Niles; Brophy, Brenor; Kopczynski, Kevin; Nair, Wood

    2014-03-11

    Disclosed is a flow coating apparatus, comprising a slot that can dispense a coating material in an approximately uniform manner along a distribution blade that increases uniformity by means of surface tension and transfers the uniform flow of coating material onto an inclined substrate such as for example glass, solar panels, windows or part of an electronic display. Also disclosed is a method of flow coating a substrate using the apparatus such that the substrate is positioned correctly relative to the distribution blade, a pre-wetting step is completed where both the blade and substrate are completed wetted with a pre-wet solution prior to dispensing of the coating material onto the distribution blade from the slot and hence onto the substrate. Thereafter the substrate is removed from the distribution blade and allowed to dry, thereby forming a coating.

  12. Self-Healing anticorrosive coatings

    DEFF Research Database (Denmark)

    Nesterova, Tatyana

    Self-healing anticorrosive coatings are multi-component so-called smart materials, which have been proposed as a way to long-lasting corrosion protection of steel structures. The presently most promising technology route is based on microcapsules, filled with active healing agents, and has been...... to capillary forces. The healing agents then start to react, form a polymer network, and =glue‘ the crack. The approach has been applied to development of an epoxy-based self-healing anticorrosive coating for above water heavy duty corrosion protection. Emphasis has been on investigation of practical issues...... associated with development and testing of this type of coating. A laboratory investigation, to identify the most suitable method for production of mechanically stable (filled with industrially relevant core materials) and forming a free-flowing powder upon drying microcapsules, has been performed. Four...

  13. Niobium pentoxide coating replacing zinc phosphate coating

    OpenAIRE

    RODRIGUES, P.R.P.; TERADA, M.; JUNIOR, O.R.A.; LOPES, A.C.; COSTA, I.; BANCZEK, E.P.

    2015-01-01

    A new coating made of niobium pentoxide, obtained through the sol-gel process, was developed for the carbon steel (SAE 1010). The corrosion protection provided by this coating was evaluated through electrochemical tests such as: open circuit potential, electrochemical impedance spectroscopy and anodic potentiodynamic polarization in NaCl 0,5 mol L-1 solution. The morphology and composition of the coatings were analyzed using scanning electronic microscopy, energy dispersive spectroscopy and X...

  14. Thermal Coatings Seminar Series Training Part 1: Properties of Thermal Coatings

    Science.gov (United States)

    Triolo, Jack

    2015-01-01

    This course will present an overview of a variety of thermal coatings-related topics, including: coating types and availability, thermal properties measurements, environmental testing (lab and in-flight), environmental impacts, contamination impacts, contamination liabilities, determination of BOLEOL values, and what does specularity mean to the thermal engineer.

  15. Cellulose nanocrystals coating – A novel paper coating for use in the graphic industry

    Directory of Open Access Journals (Sweden)

    Nikolina Puceković

    2015-12-01

    Full Text Available The rising concern about the impact of printing material on the environment is pushing the graphic industry to turn towards the use of materials derived from abundant, renewable resources. The end-result of this process would be a replacement of conventional printing materials that are often derived from unsustainable resources. The aim of this study was the application of cellulose nanocrystals (CNC coating as a novel type of sustainable coating that might eliminate use of synthetic coatings. The selected coating was prepared from cellulose nanocrystals suspension that was derived from cellulose fibrils on the laboratory scale. The coating formulation examined in this paper was not yet used on the industrial scale. Experimental research was carried out in the form of preliminary laboratory tests for offset printing application using IGT test methods of ink transfer and set-off. Paper coated with cellulose nanocrystals was used as a printing substrate, while vegetable oil-based ink was used as a printing ink in order to stay in line with environmentally preferred choice of printing materials. The results indicated an increase in surface gloss on paper coated with cellulose nanocrystals, as well as in print gloss on printed paper coated with cellulose nanocrystals. The downside of cellulose nanocrystals coating was the prolonged drying time of ink. Further research should be dedicated to improving cellulose nanocrystals coating as the formulation used in this study caused undesirable cockling and waviness on selected paper grade.

  16. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  17. CHARACTERISTICS OF PROTECTIVE COATINGS

    Directory of Open Access Journals (Sweden)

    Seljaev Vladimir Pavlovich

    2012-09-01

    Full Text Available On the basis of the computer program «Statistical analysis of color components for paint and varnish coatings», methods are suggested and experimental results are obtained for decorative characteristics polyurethane coatings.

  18. Corrosion inhibiting organic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  19. Overcoming the bottleneck of platelet lysate supply in large-scale clinical expansion of adipose-derived stem cells: A comparison of fresh versus three types of platelet lysates from outdated buffy coat-derived platelet concentrates.

    Science.gov (United States)

    Glovinski, Peter V; Herly, Mikkel; Mathiasen, Anders B; Svalgaard, Jesper D; Borup, Rehannah; Talman, Maj-Lis M; Elberg, Jens J; Kølle, Stig-Frederik T; Drzewiecki, Krzysztof T; Fischer-Nielsen, Anne

    2017-02-01

    Platelet lysates (PL) represent a promising replacement for xenogenic growth supplement for adipose-derived stem cell (ASC) expansions. However, fresh platelets from human blood donors are not clinically feasible for large-scale cell expansion based on their limited supply. Therefore, we tested PLs prepared via three methods from outdated buffy coat-derived platelet concentrates (PCs) to establish an efficient and feasible expansion of ASCs for clinical use. PLs were prepared by the freeze-thaw method from freshly drawn platelets or from outdated buffy coat-derived PCs stored in the platelet additive solution, InterSol. Three types of PLs were prepared from outdated PCs with platelets suspended in either (1) InterSol (not manipulated), (2) InterSol + supplemented with plasma or (3) plasma alone (InterSol removed). Using these PLs, we compared ASC population doubling time, cell yield, differentiation potential and cell surface markers. Gene expression profiles were analyzed using microarray assays, and growth factor concentrations in the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA). Of the three PL compositions produced from outdated PCs, removal of Intersol and resuspension in plasma prior to the first freezing process was overall the best. This specific outdated PL induced ASC growth kinetics, surface markers, plastic adherence and differentiation potentials comparable with PL from fresh platelets. ASCs expanded in PL from fresh versus outdated PCs exhibited different expressions of 17 overlapping genes, of which 10 were involved in cellular proliferation, although not significantly reflected by cell growth. Only minor differences in growth factor turnover were observed. PLs from outdated platelets may be an efficient and reliable source of human growth supplement allowing for large-scale ASC expansion for clinical use. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights

  20. NIF Anti-Reflective Coating Solutions: Preparation, Procedures and Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Suratwala, T; Carman, L; Thomas, I

    2003-07-01

    The following document contains a detailed description of the preparation procedures for the antireflective coating solutions used for NIF optics. This memo includes preparation procedures for the coating solutions (sections 2.0-4.0), specifications and vendor information of the raw materials used and on all equipment used (section 5.0), and QA specifications (section 6.0) and procedures (section 7.0) to determine quality and repeatability of all the coating solutions. There are different five coating solutions that will be used to coat NIF optics. These solutions are listed below: (1) Colloidal silica (3%) in ethanol (2) Colloidal silica (2%) in sec-butanol (3) Colloidal silica (9%) in sec-butanol (deammoniated) (4) HMDS treated silica (10%) in decane (5) GR650 (3.3%) in ethanol/sec-butanol The names listed above are to be considered the official name for the solution. They will be referred to by these names in the remainder of this document. Table 1 gives a summary of all the optics to be coated including: (1) the surface to be coated; (2) the type of solution to be used; (3) the coating method (meniscus, dip, or spin coating) to be used; (4) the type of coating (broadband, 1?, 2?, 3?) to be made; (5) number of optics to be coated; and (6) the type of post processing required (if any). Table 2 gives a summary of the batch compositions and measured properties of all five of these solutions.

  1. Nanocrystalline coatings properties forecasting

    Science.gov (United States)

    Eremin, E. N.; Yurov, V. M.; Guchenko, S. A.; Laurynas, V. Ch

    2017-06-01

    The paper considers various properties of nanocrystalline coatings. The methods of determining the surface tension of the deposited coating on the basis of the size dependence of their physical properties. It is shown that predict the mechanical properties of the coatings, their melting point, heat resistance, wear resistance, corrosion resistance, etc. It can be based on a theoretical evaluation of the surface tension.

  2. Spin coating of electrolytes

    Science.gov (United States)

    Stetter, Joseph R.; Maclay, G. Jordan

    1989-01-01

    Methods for spin coating electrolytic materials onto substrates are disclosed. More particularly, methods for depositing solid coatings of ion-conducting material onto planar substrates and onto electrodes are disclosed. These spin coating methods are employed to fabricate electrochemical sensors for use in measuring, detecting and quantifying gases and liquids.

  3. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  4. Coating of graphene

    OpenAIRE

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as a sensor, etc. The invention therefor also relates to use of coated graphene.

  5. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  6. Architecture and assembly of the Bacillus subtilis spore coat.

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of "nanodot" particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  7. Superhydrophobic Ceramic Coatings by Solution Precursor Plasma Spray

    Science.gov (United States)

    Cai, Yuxuan; Coyle, Thomas W.; Azimi, Gisele; Mostaghimi, Javad

    2016-04-01

    This work presents a novel coating technique to manufacture ceramic superhydrophobic coatings rapidly and economically. A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS). The effects of various spraying conditions including standoff distance, torch power, number of torch passes, types of solvent and plasma velocity were investigated. The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature. The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

  8. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  9. ATHENA optimized coating design

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2012-01-01

    The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...

  10. Flexible Antibacterial Coatings.

    Science.gov (United States)

    Musil, Jindřich

    2017-05-16

    This article reviews the present state of the art in the field of flexible antibacterial coatings which efficiently kill bacteria on their surfaces. Coatings are formed using a reactive magnetron sputtering. The effect of the elemental composition and structure of the coating on its antibacterial and mechanical properties is explained. The properties of Cr-Cu-O, Al-Cu-N, and Zr-Cu-N antibacterial coatings are used as examples and described in detail. The efficiency of killing of bacteria was tested for the Escherichia coli bacterium. The principle of the formation of thick, flexible antibacterial coatings which are resistant to cracking under bending is explained. It is shown that magnetron sputtering enables production of robust, several-micrometer thick, flexible antibacterial coatings for long-term use. The antibacterial coatings produced by magnetron sputtering present huge potential for many applications.

  11. Anticorrosive coatings: a review

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Kiil, Søren; Dam-Johansen, Kim

    2009-01-01

    The main objective of this review is to describe some of the important topics related to the use of marine and protective coatings for anticorrosive purposes. In this context, "protective" refers to coatings for containers, offshore constructions, wind turbines, storage tanks, bridges, rail cars...... of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers......, and inhibitive coatings are outlined. In the past decades, several alternatives to organic solvent-borne coatings have reached the commercial market. This review also presents some of these technologies and discusses some of their advantages and limitations. Finally, some of the mechanisms leading to degradation...

  12. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  13. 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.

  14. Fatigue cracking behaviour of epoxy-based marine coatings on steel substrate under cyclic tension

    OpenAIRE

    Wu, Tongyu; Irving, Phil E.; Ayre, David; Jackson, P.; Zhao, F.

    2017-01-01

    Strain controlled fatigue tests have been performed on two types of heavily filled epoxy corrosion protection coating sprayed onto a 6 mm steel substrate. Fatigue cycling was performed at R ratios of 0 and −1. The two coatings differed in their formulation and the major differences in mechanical performance were in their static strain to first crack development and their fracture toughness, where Coating A was significantly tougher than coating B. During strain cycling coating crack developme...

  15. Type IX secretion: the generation of bacterial cell surface coatings involved in virulence, gliding motility and the degradation of complex biopolymers.

    Science.gov (United States)

    Veith, Paul D; Glew, Michelle D; Gorasia, Dhana G; Reynolds, Eric C

    2017-10-01

    The Type IX secretion system (T9SS) is present in over 1000 sequenced species/strains of the Fibrobacteres-Chlorobi-Bacteroidetes superphylum. Proteins secreted by the T9SS have an N-terminal signal peptide for translocation across the inner membrane via the SEC translocon and a C-terminal signal for secretion across the outer membrane via the T9SS. Nineteen protein components of the T9SS have been identified including three, SigP, PorX and PorY that are involved in regulation. The inner membrane proteins PorL and PorM and the outer membrane proteins PorK and PorN interact and a complex comprising PorK and PorN forms a large ring structure of 50 nm in diameter. PorU, PorV, PorQ and PorZ form an attachment complex on the cell surface of the oral pathogen, Porphyromonas gingivalis. P. gingivalis T9SS substrates bind to PorV suggesting that after translocation PorV functions as a shuttle protein to deliver T9SS substrates to the attachment complex. The PorU component of the attachment complex is a novel Gram negative sortase which catalyses the cleavage of the C-terminal signal and conjugation of the protein substrates to lipopolysaccharide, anchoring them to the cell surface. This review presents an overview of the T9SS focusing on the function of T9SS substrates and machinery components. © 2017 John Wiley & Sons Ltd.

  16. Preliminary coating design and coating developments for ATHENA

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland

    2011-01-01

    We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used...... for these designs and present test results from coatings....

  17. Decoupling and tuning competing effects of different types of defects on flux creep in irradiated YBa2Cu3O7-δ coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Eley, S.; Leroux, M.; Rupich, M. W.; Miller, D. J.; Sheng, H.; Niraula, P. M.; Kayani, A.; Welp, U.; Kwok, W. -K.; Civale, L.

    2016-11-15

    YBa2Cu3O7-δ coated conductors (CCs) have achieved high critical current densities (J c) that can be further increased through the introduction of additional defects using particle irradiation. However, these gains are accompanied by increases in the flux creep rate, a manifestation of competition between the different types of defects. Here, we study this competition to better understand how to design pinning landscapes that simultaneously increase J c and reduce creep. CCs grown by metal organic deposition show non-monotonic changes in the temperature-dependent creep rate, S(T). Notably, in low fields, there is a conspicuous dip to low S as the temperature (T) increases from ~20 to ~65 K. Oxygen-, proton-, and Au-irradiation substantially increase S in this temperature range. Focusing on an oxygen-irradiated CC, we investigate the contribution of different types of irradiation-induced defects to the flux creep rate. Specifically, we study S(T) as we tune the relative density of point defects to larger defects by annealing both an as-grown and an irradiated CC in O2 at temperatures T A = 250 °C–600 °C. We observe a steady decrease in S(T > 20 K) with increasing T A, unveiling the role of pre-existing nanoparticle precipitates in creating the dip in S(T) and point defects and clusters in increasing S at intermediate temperatures.

  18. The cell-type specific uptake of polymer-coated or micelle-embedded QDs and SPIOs does not provoke an acute pro-inflammatory response in the liver

    Directory of Open Access Journals (Sweden)

    Markus Heine

    2014-09-01

    Full Text Available Semiconductor quantum dots (QD and superparamagnetic iron oxide nanocrystals (SPIO have exceptional physical properties that are well suited for biomedical applications in vitro and in vivo. For future applications, the direct injection of nanocrystals for imaging and therapy represents an important entry route into the human body. Therefore, it is crucial to investigate biological responses of the body to nanocrystals to avoid harmful side effects. In recent years, we established a system to embed nanocrystals with a hydrophobic oleic acid shell either by lipid micelles or by the amphiphilic polymer poly(maleic anhydride-alt-1-octadecene (PMAOD. The goal of the current study is to investigate the uptake processes as well as pro-inflammatory responses in the liver after the injection of these encapsulated nanocrystals. By immunofluorescence and electron microscopy studies using wild type mice, we show that 30 min after injection polymer-coated nanocrystals are primarily taken up by liver sinusoidal endothelial cells. In contrast, by using wild type, Ldlr-/- as well as Apoe-/- mice we show that nanocrystals embedded within lipid micelles are internalized by Kupffer cells and, in a process that is dependent on the LDL receptor and apolipoprotein E, by hepatocytes. Gene expression analysis of pro-inflammatory markers such as tumor necrosis factor alpha (TNFα or chemokine (C-X-C motif ligand 10 (Cxcl10 indicated that 48 h after injection internalized nanocrystals did not provoke pro-inflammatory pathways. In conclusion, internalized nanocrystals at least in mouse liver cells, namely endothelial cells, Kupffer cells and hepatocytes are at least not acutely associated with potential adverse side effects, underlining their potential for biomedical applications.

  19. COMPARISON OF SOL-GEL SILICATE COATINGS ON Ti SUBSTRATE

    Directory of Open Access Journals (Sweden)

    DIANA HORKAVCOVÁ

    2012-12-01

    Full Text Available The objective of the submitted work was to prepare and to characterize two types of silicate coatings prepared by the sol-gel method using the dip-coating technique on a titanium substrate. Efforts have been made to use mechanical properties of bio-inert titanium and bioactive properties of a silicate layer enriched with an admixture of compounds identified below. The first group consisted of silicate coatings containing silver, brushite and monetite. The other group of silicate coatings contained calcium nitrate and triethyl phosphate. Mechanically and chemically treated titanium substrates were dipped into sols and dried and fired. Silicate coatings from the first group were also chemically treated in 10 mol.l-1 solution of sodium hydroxide. All coatings were measured to determine their adhesive and bioactive properties and furthermore the antibacterial properties were tested in the case of first group. Surfaces of the coated substrates were investigated after the firing and after the individual tests with optical and electron microscopy and X-ray microdiffraction. A tape test demonstrated excellent adhesive property of all coatings to the substrate, classified with degree 5. A static in vitro test demonstrated bioactivity of nearly all the coatings. The basic silicate coating from the first group and one type of coating from the second group were identified as inert. Antibacterial properties of silicate coatings containing silver showed to be different when tested against Escherichia coli bacteria. A complete inhibition of the growth of bacteria under our experimental conditions was observed for the coating containing silver and monetite and a partial inhibition of the growth of bacteria for coatings containing silver and silver in combination with brushite.

  20. Improved Manganese Phosphate Coatings

    Science.gov (United States)

    1975-04-01

    AD K/ . / R-TR-75-034 IMPROVED MANGANESE PHOSPHATE COATINGS HENRY CRAIN - APRIL 1975 RESEARCH DIRECTORATE DISTRIBUTION STATEMENT Approved for public...which superior manganese phosphate coatings are producel. The phosphate coatings were applied at temp- eratures above 2124F and with -.anganese...temperature for the conversion of mlnganese dihydrogen phosphate [(P(HjPO•’)] to manganese phosphate [Nns(PO4)J]. 1 A ii UNCLASSIFIED SE[CURITY CL. A

  1. Nanostructured Protective Coatings

    Science.gov (United States)

    2006-01-01

    understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V used for turbine blades, and developing a versatile...Phase I objectives, particularly in enhancing the understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V ...understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V used for turbine blades, and developing a versatile

  2. Smooth Compliant Antifoulant Coatings.

    Science.gov (United States)

    1982-09-30

    team reviewed the state of the art in marine antifoulant tech- nology. As part of this technology review, the team visited the Naval Ship Research and...high payoff is the incorporation of the biocide within the substrate polymer chain. This permits the antifoulant to be held chemi- cally rather than by...traditionally used red lead as a basis for protection against marine fouling. The antifoulant coating consists of a metal pretreatment coat, four coats of an

  3. Bio-based coatings for reducing water sorption in natural fibre reinforced composites

    CSIR Research Space (South Africa)

    Mokhothu, Thabang H

    2017-10-01

    Full Text Available In this study, bio-based coatings were used for reducing water sorption of composites containing flame retardant treated natural fibres and phenolic resin. Two types of coatings; polyfurfuryl alcohol resin (PFA) and polyurethane (PU) were used...

  4. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  5. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  6. Microstructure and Behaviors of Nano Composite Coating

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xi-ying; QIAN Shi-qiang; LI Wei-hong; LI Pei-yao; LI Man-ping

    2004-01-01

    Nano composite coatings are fabricated by electro brush plating containing various nano particles (Al2O3, SiO2and ZrO2). Its surface morphology and microstructure are observed by means of S-2700 scanning electron microscopy (SEM). And the mechanical behaviors of nano composite coating are analyzed. The results show that microstructure of nano composite coating is obviously fine because of nano particles. Micro hardness at room temperature increases with the increase of nano particles content. The wear resistance and hardness at high temperature are also improved. The strengthening effect is differentiated by the type and content of nano particles. This is due to the combination of dispersion strengthening and grain size strengthening.Key Words: Nano particles, composite coating, electro brush plating, behaviors

  7. A Multiple-Action Self-Healing Coating

    OpenAIRE

    Alexander eLutz; Alexander eLutz; Otto evan den Berg; Jan eWielant; Iris eDe Graeve; Herman eTerryn

    2016-01-01

    This paper describes a self-healing coating for corrosion protection of metals which combines two different types of self-healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT) was loaded into layered double hydroxide (LDH) carriers which were mixed into an acrylated polycaprolactone polyurethane based shape recovery coating and applied on Hot Dip Galvanized steel (HDG). The effect of triggered release of MBT on the protection of HDG became visibl...

  8. A Multiple-Action Self-Healing Coating

    OpenAIRE

    Lutz, Alexander; van den Berg, Otto; Wielant, Jan; De Graeve, Iris; Terryn, Herman

    2016-01-01

    This article describes a self-healing coating for corrosion protection of metals, which combines two different types of self-healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT) was loaded into layered double hydroxide (LDH) carriers that were mixed into an acrylated polycaprolactone polyurethane-based shape-recovery coating and applied on hot-dip galvanized steel (HDG). The effect of triggered release of MBT on the protection of HDG became visi...

  9. Superhydrophobic silica coating by dip coating method

    Energy Technology Data Exchange (ETDEWEB)

    Mahadik, Satish A., E-mail: superhydrophobicmaterial2100@gmail.com [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Parale, Vinayak; Vhatkara, Rajiv S.; Mahadik, Dinesh B.; Kavale, Mahendra S. [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Wagh, Pratap B.; Gupta, Satish [Applied Physics Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085 (India); Gurav, Jyoti [Empa, Advanced Materials Processing laboratory, 3602 Thun (Switzerland)

    2013-07-15

    Herein, we report a simple and low cost method for the fabrication of superhydrophobic coating surface on quartz substrates via sol-gel dip coating method at room temperature. Desired surface chemistry and texture growth for superhydrophobicity developed under double step sol–gel process at room temperature. The resultant superhydrophobic surfaces were characterized by Field-emission scanning electron microscopy (FE-SEM), Atomic force microscopy (AFM), water contact angle (WCA) measurement, differential thermal gravimetric analysis-differential thermal analysis (TGA-DTA) calorimetry and optical spectrometer. Coating shows the ultra high water contact angle about 168 ± 2° and water sliding angle 3 ± 1° and superoleophilic with petroleum oils. This approach allows a simple strategy for the fabrication process of superhydrophilic–superhydrophobic on same surfaces with high thermal stability of superhydrophobicity up to 560 °C. Thus, durability, special wettability and thermal stability of superhydrophobicity expand their application fields.

  10. Rocket Combustion Chamber Coating

    Science.gov (United States)

    Holmes, Richard R. (Inventor); McKechnie, Timothy N. (Inventor)

    2001-01-01

    A coating with the ability to protect (1) the inside wall (i.e., lining) of a rocket engine combustion chamber and (2) parts of other apparatuses that utilize or are exposed to combustive or high temperature environments. The novelty of this invention lies in the manner a protective coating is embedded into the lining.

  11. Coated electroactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali

    2016-08-30

    A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

  12. Coating of graphene

    NARCIS (Netherlands)

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as

  13. Molecular Adsorber Coating

    Science.gov (United States)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  14. Preparation of ferrite-coated MFM cantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Koblischka, M.R. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany)]. E-mail: m.koblischka@mx.uni-saarland.de; Kirsch, M. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany); Wei, J. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany); Sulzbach, T. [Nanoworld Services GmbH, Schottkystrasse 10, D-91058 Erlangen (Germany); Hartmann, U. [Institute of Experimental Physics, University of Saarbruecken, P. O. Box 151150, D-66041 Saarbruecken (Germany)

    2007-09-15

    Ferrite-coated magnetic force microscopy (MFM) cantilevers were prepared for the use with a high-frequency MFM (HF-MFM) setup. The ferrite coatings were fabricated by means of radio frequency (RF) magnetron sputtering directly on the Si surface. Two types of ferrites were employed in this study: NiZnFe{sub 2}O{sub 4} spinel and Co{sub 2} Z-type hexaferrite (Ba{sub 3}Co{sub 2}Fe{sub 24}O{sub 41}, BCFO). The typical thickness of the coatings was 50 nm. For comparison, ferrite samples on (1 0 0) and (1 1 1)-oriented Si substrates (analogous to the surfaces of the cantilevers) were prepared. Successful HF-MFM imaging was performed with both types of cantilevers using harddisk writer poles as samples. The HF-MFM images obtained by ferrite-coated cantilevers evidently reveal more details of the magnetic field distribution of the writer poles up to the GHz range than conventional CoCr-coated MFM cantilevers.

  15. FY 2000 report on the results of the regional consortium R and D project - Regional new technology creation R and D. Development of a composite type wood drier applied with functional coating; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo - chiiki shingijutsu soshutsu kenkyu kaihatsu. Kinosei himaku oyo no fukugogata mokuzai kansoki no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The development was proceeded with of a drier which is low in cost, excellent in durability and applicable to the small amount/many kinds of tree such as fittings, furniture and folkcraft. At the same time, for realization of high durability, the development was made of the technology for repelling acidic resin liquid, etc. generated during drying and forming the corrosion-resistant composite coating on the surface of wall material, etc. The water repellent material is white powder of the pitch fluoride (fluorinated pitch), which has acidity resistance and super water repellency. Further, the composite coating was formed by spraying the fluorinated pitch by the wire type gas spraying device using the composite wire made by filling the fluorinated pitch into metal tube. Studies were made in the following four fields: 1) development of the functional coating formation technology; 2) development of wood drier; 3) market survey; 4) comprehensive investigational study. In 1), durability as a wood dryer material for the composite coating formed material was confirmed. As to the composite wire manufacturing method, the manufacturing technology of kg unit was established by controlling the state of aggregation of the fluorinated pitch. (NEDO)

  16. Fluorine Based Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Jean-Denis Brassard

    2012-05-01

    Full Text Available Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17 molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings.

  17. Novel surface coating materials for endodontic dental implant

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, M.H. [Isfahan Univ. of Technology, Materials Engineering Dept., Isfahan (Iran, Islamic Republic of); Mortazavi, V.; Moosavi, S.B. [Isfahan Univ. of Medical Sciences, Faculty of Dentistry, Isfahan (Iran, Islamic Republic of)

    2003-07-01

    The aim of this study was to design and produce novel coating materials in order to obtain two goals including; improvement of the corrosion behavior of metallic dental endodontic implant and the bone osteointegration simultaneously. Stainless steel 316L (SS) was used as a metallic substrate and a novel Hydroxyapatite/Titanium (HA/Ti) composite coating was prepared on it. Structural characterization techniques including XRD, SEM and EDX were utilized to investigate the microstructure and morphology of the coating. Electrochemical tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. Two types of endodontic implants including; SS with and without (HA/Ti) composite coating were prepared and subsequently implanted in the mandibular canine of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, osteointegration evaluation and histopathological interpretation was carried out using SEM and optical microscopy. Results indicate that the novel HA/Ti composite coating improves the corrosion behavior and biocompatibility of SS endodontic dental implant. The clinical evaluation (in vivo test) results showed that there was significant difference in osteointegration between coated and uncoated endodontic dental implants and average bone osteointegration of coated implants were more than uncoated implants. The histopathological results and bone tissue response to the coated implants was acceptable and it was concluded that HA/Ti composite coated SS could be used as well as an endodontic dental implant. (author)

  18. Aluminide protective coatings on high–temperature creep resistant cast steel

    Directory of Open Access Journals (Sweden)

    J. Kubicki

    2009-10-01

    Full Text Available This paper presents the results of research on aluminide protective coatings manufactured on high–temperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, especially at high carburizing potential atmosphere. Coatings were obtained on cast steel type G–XNiCrSi36–18 with the following methods: pack cementation, paste method, cast method and slurry cementation. The phase composition, thickness and morphology of coatings were determined. Coatings capacity of carbon diffusion inhibition and thermal shocks resistance of coatings were determined with different methods. It was found, that all of the coatings reduce carbon diffusion in different degree and all coatings liable to degradation in consequence cracking and oxidation. Coating life time is mainly dependent on morphology, phase composition and service condition (thermal shocks first of all.

  19. Corrosion performance of inorganic coatings in seawater

    NARCIS (Netherlands)

    Zhang, X.; Buter, S.J.; Ferrari, G.M.; Westing, E. van; Kowalski, L.

    2011-01-01

    Inorganic coatings are widely used to protect carbon steel hydraulic cylinder rods from wear and corrosion in aggressive offshore environment. Different types of lay-ers such as Ni/Cr, Al2O3, Cr2O3, TiO2, and Inconel 625 layers were applied to the carbon steels by plasma, High Velocity Oxygen Fuel

  20. Improved coating for silica fiber based ceramic Reusable Surface Insulation (CRSI)

    Science.gov (United States)

    Ormiston, T. J.

    1974-01-01

    A series of coatings was developed for the space shuttle type silica fiber insulation system and characterized for optical and physical properties. Reentry simulation tests were run using a radiant panel and also using a hypersonic plasma arc. The coatings produced had improved physical and optical properties as well as greater reuse capability over the GE version of the JSC-0042 coating.

  1. Rapid Assessment of Tablet Film Coating Quality by Multispectral UV Imaging

    DEFF Research Database (Denmark)

    Klukkert, Marten; Wu, Jian X.; Rantanen, Jukka

    2016-01-01

    and coated with a polyvinyl alcohol-polyethylene glycol graft copolymer using a pan coater. It was demonstrated that the coating intactness can be assessed accurately and fast by UV imaging. The different types of coating defects could be differentiated and localized based on multivariate image analysis...

  2. Hybrid calcium phosphate coatings for implants

    Science.gov (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.

    2016-08-01

    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  3. Surface cracking in resistance seam welding of coated steels

    Energy Technology Data Exchange (ETDEWEB)

    Adonyi, Y.; Kimchi, M.

    1994-12-31

    In this experimental work, the focus was on the understanding the electrode-wheel/coated steel surface phenomena by building operational lobes and by correlating the weld quality with static-and dynamic-contact-resistance variation during welding. Conventional AC, DC, and electrode-wire resistance-seam weldability of printed zinc-coated and hot-dipped tin-coated steel was performed in this work, as compared with traditional lead-tin (terne) coating used as reference material. Variables included steel substrate type, welding equipment type, electrode-wheel cleaning practice, and electrode-wire geometry. Optic and electron microscopy were used for the evaluation of specimens extracted from longitudinal cross-sections of representative welds. The size and morphology of surface cracks was characterized and correlated with variations in the above-mentioned parameters. It was found that the tin-coated (unpainted) steel sheet had a superior all-together performance to the zinc-coated steel and terne-coated steel, both in terms of wider weldability lobes and lesser surface cracking. The extent of surface cracking was greatly reduced by using the electrode-wire seam welding process using a longitudinally grooved wire profile, which also widened the corresponding weldability lobes. It was also found that the extent of cracking depended on the electrode knurl geometry, substrate type, and the presence of conductive paint applied on top of the metallic coating. An attempt was made to characterize the specific mechanisms governing the LME phenomenon for the lead-, zinc and tin-based coating systems and to assess the potential for crack propagation in the welds. The dynamic contact resistance was found to be a good measure of the welding process stability and an indicator of defect formation. It was found that the ratio between the static and dynamic contact resistances of the tin-coated sheet was considerably lower than similar ratios for bare and zinc-coated sheet.

  4. Aluminum phosphate coatings

    Science.gov (United States)

    Sambasivan, Sankar; Steiner, Kimberly A.; Rangan, Krishnaswamy K.

    2007-12-25

    Aluminophosphate compounds and compositions as can be used for substrate or composite films and coating to provide or enhance, without limitation, planarization, anti-biofouling and/or anti-microbial properties.

  5. Inorganic Coatings Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The inorganic Coatings Lab provides expertise to Navy and Joint Service platforms acquisition IPTs to aid in materials and processing choices which balance up-front...

  6. Friction surfaced Stellite6 coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rao, K. Prasad; Damodaram, R. [Department of Metallurgical and Materials Engineering - Indian Institute of Technology Madras, Chennai 600 036 (India); Rafi, H. Khalid, E-mail: khalidrafi@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Ram, G.D. Janaki [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Reddy, G. Madhusudhan [Metal Joining Group, Defence Metallurgical Research Laboratory (DMRL) Kanchanbagh, Hyderabad 500 058 (India); Nagalakshmi, R. [Welding Research Institute, Bharat Heavy Electricals Limited, Tiruchirappalli 620 014 (India)

    2012-08-15

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  7. Spin coating apparatus

    Science.gov (United States)

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  8. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  9. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  10. Coated microneedles for transdermal delivery

    OpenAIRE

    Gill, Harvinder S.; Prausnitz, Mark R.

    2006-01-01

    Coated microneedles have been shown to deliver proteins and DNA into the skin in a minimally invasive manner. However, detailed studies examining coating methods and their breadth of applicability are lacking. This study’s goal was to develop a simple, versatile and controlled microneedle coating process to make uniform coatings on microneedles and establish the breadth of molecules and particles that can be coated onto microneedles. First, microneedles were fabricated from stainless steel sh...

  11. Coated particle waste form development

    Energy Technology Data Exchange (ETDEWEB)

    Oma, K.H.; Buckwalter, C.Q.; Chick, L.A.

    1981-12-01

    Coated particle waste forms have been developed as part of the multibarrier concept at Pacific Northwest Laboratory under the Alternative Waste Forms Program for the Department of Energy. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low-temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed (FB) coaters, screw agitated coaters (SAC), and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated at PNL as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders-of-magnitude increase in chemical durability. Because the aluminum coatings were porous, the superior leach resistance must be due to either a chemical interaction or to a pH buffer effect. Because they are complex, coated waste form processes rank low in process feasibility. Of all the possible coated particle processes, plasma sprayed marbles have the best rating. Carbon coating of pellets by CVD ranked ninth when compared with ten other processes. The plasma-spray-coated marble process ranked sixth out of eleven processes.

  12. A review of the use of wear-resistant coatings in the cutting-tool industry

    Science.gov (United States)

    Salik, J.

    1983-01-01

    The main mechanisms involved in the wear of cutting tools are reviewed. Evaluation of the different coating properties required for the reduction of the different kinds of wear was also reviewed. The types of coatings and their ranges of applicability are presented and discussed in view of their properties. Various coating processes as well as their advantages and shortcomings are described. Potential future developments in the field of wear-resistant coatings are discussed.

  13. Chitosan coating and films : evaluation of surface, permeation, mechanical and thermal propertiess

    OpenAIRE

    Casariego, A.; Souza, B.W.S.; L. Cruz; Díaz, R; Teixeira, J. A.; A.A. Vicente

    2008-01-01

    The potentialities of chitosan (from lobster of the cuban coasts) coating to extend the shelf life of vegetables were evaluated. To do so, the surface properties of tomato and carrot were characterized and the wettability properties of chitosan coatings were studied. In such coatings, chitosan concentration and effects of type and concentration of plasticizer or surfactant on wettability of chitosan coatings were evaluated, as well as the respective barrier and mechanical properti...

  14. Properties of Lightning Strike Protection Coatings

    Science.gov (United States)

    Gagne, Martin

    Composite materials are being increasingly used by many industries. In the case of aerospace companies, those materials are installed on their aircraft to save weight, and thus, fuel costs. These aircraft are lighter, but the loss of electrical conductivity makes aircraft vulnerable to lightning strikes, which hit commercial aircrafts on average once per year. This makes lightning strike protection very important, and while current metallic expanded copper foils offer good protection, they increase the weight of composites. Therefore, under the CRIAQ COMP-502 project, a team of industrial partners and academic researchers are investigating new conductive coatings with the following characteristics: High electromagnetic protection, high mechanical resistance, good environmental protection, manufacturability and moderate cost. The main objectives of this thesis, as part of this project, was to determine the main characteristics, such as electrical and tribomechanical properties, of conductive coatings on composite panels. Their properties were also to be tested after destructive tests such as current injection and environmental testing. Bombardier Aerospace provided the substrate, a composite of carbon fiber reinforced epoxy matrix, and the current commercial product, a surfacing film that includes an expanded copper foil used to compare with the other coatings. The conductive coatings fabricated by the students are: silver nanoparticles inside a binding matrix (PEDOT:PSS or a mix of Epoxy and PEDOT:PSS), silvered carbon nanofibers embedded in the surfacing film, cold sprayed tin, graphene oxide functionalized with silver nanowires, and electroless plated silver. Additionally as part of the project and thesis, magnetron sputtered aluminum coated samples were fabricated. There are three main types of tests to characterize the conductive coatings: electrical, mechanical and environmental. Electrical tests consist of finding the sheet resistance and specific resistivity

  15. Dry Sintered Metal Coating of Halloysite Nanotubes

    Directory of Open Access Journals (Sweden)

    James C. Nicholson

    2016-09-01

    Full Text Available Halloysite nanotubes (HNTs are a naturally-occurring aluminosilicate whose dimensions measure microns in length and tens of nanometers in diameter. Bonding defects between the alumina and silica lead to net negative and positive charges on the exterior and interior lumen, respectively. HNTs have been shown to enhance the material properties of polymer matrices and enable the sustained release of loaded chemicals, drugs, and growth factors. Due to the net charges, these nanotubes can also be readily coated in layered-depositions using the HNT exterior lumen’s net negative charge as the basis for assembly. These coatings are primarily done through wet chemical processes, the majority of which are limited in their use of desired chemicals, due to the polarity of the halloysite. Furthermore, this restriction in the type of chemicals used often requires the use of more toxic chemicals in place of greener options, and typically necessitates the use of a significantly longer chemical process to achieve the desired coating. In this study, we show that HNTs can be coated with metal acetylacetonates—compounds primarily employed in the synthesis of nanoparticles, as metal catalysts, and as NMR shift reagents—through a dry sintering process. This method was capable of thermally decaying the metal acetylacetonate, resulting in a free positively-charged metal ion that readily bonded to the negatively-charged HNT exterior, resulting in metallic coatings forming on the HNT surface. Our coating method may enable greater deposition of coated material onto these nanotubes as required for a desired application. Furthermore, the use of chemical processes using toxic chemicals is not required, thus eliminating exposure to toxic chemicals and costs associated with the disposal of the resultant chemical waste.

  16. Surface coating for prevention of metallic seed migration in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunseok; Park, Jong In [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Won Seok; Park, Min [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 151-742 (Korea, Republic of); Son, Kwang-Jae [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bang, Young-bong [Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Choy, Young Bin, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul 110-744 (Korea, Republic of); Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon, E-mail: ybchoy@snu.ac.kr, E-mail: sye@snu.ac.kr [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 151-742 (Korea, Republic of); Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of); Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2015-06-15

    Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress between the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy.

  17. Microstructure and Behaviors of Nano Composite Coating

    Institute of Scientific and Technical Information of China (English)

    ZHOUXi-ying; QIANShi-qiang; LiWei-hong; LIPei-yao; LIMan-ping

    2004-01-01

    Nano composite coatings are fabricated by electro brash plating containing various nano particles (Al2O3, SiO2 and ZrO2). Its surface morphology and microstructure are observed by means of S-2700 scanning elect-on microscopy (SEMI, And the mechanical behaviors of nano composite coating are analyzed. The results show that microstructure of nano composite coating is obviously fine because of nano particles. Micro hardness at room temperature increases with the increase of nano particles content. The wear resistance and hardness at high temperature are also improved. The strengthening effect is differentiated by the type and content of nano particle.s, This is due to the combination of dispersion strengthening and grain size strengthening.

  18. Steam initiated hydrotalcite conversion coatings

    DEFF Research Database (Denmark)

    Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie

    2018-01-01

    in the following order: K2S2O8 > Na2SO4 > NH4NO3 > KNO3. Post-coating rinsing by Mg(CH3COO)2, in addition to Ce- and La- based salts, is capable of sealing the porous Al-Li HT coatings and increasing the corrosion resistance ability. The Ce modified Al-Li HT coatings show better corrosion protection than the La...... modified coatings, due to a behaviour of “active corrosion protection” that enables precipitation of insoluble Ce(IV) oxides to reinforce the existed HT coatings........ A range of coating processesased on the formation of HT surface layers has been developed to examine its effect on the coating's thicknessnd corrosion resistance properties. These varieties include pre-coating cleaning (grid blasting vs. chemicaltching), metal species in HT compounds (Al-Zn HT coating vs...

  19. Protective Woodcutting Tool Coatings

    Directory of Open Access Journals (Sweden)

    Svetlana D. Latushkina

    2016-01-01

    Full Text Available The modern woodworking industry applies resource-saving, environmentally appropriate technologies, providing both the metal removal performance enhancement and functioning with the optimal economic factors. Progressive cutting parameters require the application of the high-reliability cutting tools, eliminating machine-tool equipment standstill and increased cost of the expensive tool materials. In this paper it is suggested to increase the wood-cutting tool efficiency by means of the vacuum-arc separated coating deposition process optimization. The droplets are one of the main problems while generating vacuum-arc coatings, and they have a bad influence on the quality and operational coatings characteristics. The application of the separated system, allowing minimize the droplets content, is one of the most promising ways to solve this problem. Vacuum-arc deposition technique was used in this work to generate multicomponent coatings. The coatings deposition was directly carried out on the modernized vacuum-arc plant, equipped by Y-shaped macroparticles separator.

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

    National Research Council Canada - National Science Library

    2008-01-01

    .... In brief, Task 1 involved the construction and assembly of the coating system and supporting infrastructure, which was used for the scale-up and production of 1-lb batches of coated magnesium powder...

  1. Superheating in coated niobium

    OpenAIRE

    T. Junginger; Wasserman, W.; Laxdal, R. E.

    2017-01-01

    Using muon spin rotation it is shown that the field of first flux penetration H_entry in Nb is enhanced by about 30% if coated with an overlayer of Nb_3Sn or MgB_2. This is consistent with an increase from the lower critical magnetic field H_c1 up to the superheating field H_sh of the Nb substrate. In the experiments presented here coatings of Nb_3Sn and MgB_2 with a thickness between 50 and 2000nm have been tested. H_entry does not depend on material or thickness. This suggests that the ener...

  2. Advanced Coating Removal Techniques

    Science.gov (United States)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  3. Mechanically Invisible Polymer Coatings

    DEFF Research Database (Denmark)

    2014-01-01

    phase comprises particles, said particles comprising a filler material and an encapsulating coating of a second polymeric material, wherein the backbones of the first and second polymeric materials are the same. The composition may be used in electroactive polymers (EAPs) in order to obtain mechanically......The present invention relates to a composition comprising encapsulated particles in a polymeric material. The composition comprises a continuous phase and a discontinuous phase incorporated therein, wherein the continuous phase comprises a first polymeric material and wherein the discontinuous...... invisible polymer coatings....

  4. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a

  5. 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...... (KCl) crystals with ethylcellulose (EC). Vibrations were measured with two different types of accelerometers. Different positions for placing the accelerometers and two different product containers were included in the study. Top spray coating of KCl was chosen as a ‘worst case' scenario from a coating...... point perspective. The acoustic monitoring has the potential of summarising the commonly used means to monitor the coating process. The best partial least squares (PLS) regressions, obtained by the high frequency accelerometer, showed for the release a correlation coefficient of 0.92 and a root mean...

  6. Universal Nature-Inspired Coatings for Preparing Noncharging Surfaces.

    Science.gov (United States)

    Fang, Yan; Gonuguntla, Spandhana; Soh, Siowling

    2017-09-20

    Static charge generated by contact electrification on surfaces can lead to many undesirable consequences such as a reduction in the efficiency of manufacturing processes, damage to equipment, and explosions. However, it is extremely challenging to avoid contact electrification because it is ubiquitous: almost all types of materials charge on contact. Here, we coated materials with naturally occurring polydopamine (PDA) and tannic acid (TA) for preparing noncharging surfaces. Importantly, these coatings are very versatile and can be coated on a wide range of materials, including metals, inorganic materials, semiconductors, and polymers. Once coated, the amount of charge generated was found to reduce dramatically at different humidities. The reduction in charge may be due to the radical-scavenging property of PDA and TA. This simple general approach is ideal for coating the vast variety of materials that need to resist charging by contact electrification.

  7. Bioresponsive polymer coating on nanoparticles

    Science.gov (United States)

    Laemthong, Tunyaboon

    Nanotechnology incorporated with molecular biology became a promising way to treat cancer. The size of nanoparticles enables them to overcome the side effects noticed in cancer treatment like chemotherapy and surgery. Various types and shapes of nanoparticles have been synthesized and used in drug delivery to tumor sites. However, one of problems of using these nanoparticles is the aggregation after injecting them into human body due to flow rate of bloodstream. The coagulation and aggregation will result in clogging blood vessel and lower therapeutic efficacy. In this thesis, a solution to the aggregation problem was proposed, which is coating biopolymer on nanoparticles (NPs). The experimental sections covered synthesis and characterization of breast cancer specific targeting drug-encapsulated NPs and biopolymer coating on the surface of Au-Fe3O4 NPs for thermal therapy. Furthermore, in vitro studies of these NPs with breast cancer cells were also included. The specific targeting anticancer drug-encapsulated NRs showed significant inhibition in BT-474 breast cancer cell growth. The Au-Fe3O4 NPs has a possibility to treat cancer cells using the thermal therapy approach.

  8. Corrosion Testing of 304L SS 3013 Inner Container and Teardrop Samples

    Energy Technology Data Exchange (ETDEWEB)

    Tokash, Justin Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hill, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lillard, Scott [Univ. of Akron, OH (United States); Joyce, Stephen Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tegtmeier, Eric Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-27

    The Department of Energy (DOE) 3013 Standard specifies a minimum of two containers to be used for the storage of plutonium-bearing materials containing at least 30 wt.% plutonium and uranium. Three nested containers are typically used, the outer, inner, and convenience containers, shown in Figure 1. Both the outer and inner containers are sealed with a weld while the innermost convenience container must not be sealed. Lifetime of the containers is expected to be fifty years. The containers are fabricated of austenitic stainless steels (SS) due to their high corrosion resistance. Potential failure mechanisms of the storage containers have been examined by Kolman and Lillard et al.

  9. Towards the modelling of recrystallization phenomena in multi-pass conditions: application to 304L steel

    OpenAIRE

    Huang, Ke

    2011-01-01

    Recrystallization, which can occur dynamically or statically, is an important phenomenon causing microstructure changes in deformed metals and therefore affecting the properties of the material. Even though extensive investigations have been carried out on the numerical modeling of recrystallization, the literature lacks accurate recrystallization models which are able to predict microstructure evolution under multi-pass conditions. Although some efforts have been reported in this direction, ...

  10. Aesthetic coatings for steel bridge components.

    Science.gov (United States)

    2013-11-01

    The effectiveness of aesthetic coating systems for steel bridges was studied. Twelve 2-coat, 3-coat, and duplex : coating systems were selected and subjected to a series of accelerated weathering and mechanical tests to : determine their performance....

  11. Workshop on coatings needs in the auto industry

    Energy Technology Data Exchange (ETDEWEB)

    Courtright, E L

    1993-05-01

    New lightweight materials continue to be of great interest to the automotive industry. Compared to 20 years ago, the average vehicle weight has been reduced by almost a fourth, and fuel economy has nearly doubled. While continued improvements are both desirable and possible, materials choices are narrowing and the manufacturing methods needed to produce advanced materials systems are much more costly. The incentives remain high, however; particularly in view of large payoffs associated with minimizing structural weight in electric and hybrid-type vehicles. One generic solution is to develop coatings that will enable the use of lower cost materials. A workshop on coatings needs in the auto industry was held in Detroit, Michigan on October 27 and 28, 1992 with the objective of identifying research needs where coatings could enhance the use of energy efficient lightweight materials for automotive applications. Four generic areas had previously been identified auto manufacturers and industry suppliers. These were: Wear Coatings, Hard Protective Coatings for Plastics, Solar Control Coatings, and Process Manufacturing Issues. The development of coatings and coating technologies for lightweight metals and metal matrix composites emerged as the number one research needs. This need underscores the interest in making better use of existing lightweight metals, e.g. magnesium, aluminum, and their alloys. Coatings to protect plastics and reinforced plastic composites were also identified as a major area of importance. Protection from automotive liquids and gases. Coatings that will improve mar resistance, resist UV degradation, or eliminate degradation due to moisture absorption are also needed. Accordingly, manufacturability issues associated with coating light metals, e.g. aluminum, magnesium, and metal matrix composites with wear and corrosion resistant materials, were identified as a high priority research need.

  12. Mechanisms of Military Coatings Degradation

    Science.gov (United States)

    2003-08-01

    volume and bulk film compaction. Coating A is a less sterically and thermally stable biuret trimer of HDI in comparison to the HDI of coating system...developed coatings systems used by the Army, Marine Corps and Air Force. This study has incorporated numerous analytical tools and methods in an effort to...blistering. Peel away was evaluated as per ASTM D 3359, Method A and blistering was evaluated as per ASTM D 714. Coating systems are summarized

  13. Coating method for graphite

    Science.gov (United States)

    Banker, J.G.; Holcombe, C.E. Jr.

    1975-11-06

    A method of limiting carbon contamination from graphite ware used in induction melting of uranium alloys is provided. The graphite surface is coated with a suspension of Y/sub 2/O/sub 3/ particles in water containing about 1.5 to 4 percent by weight sodium carboxymethylcellulose.

  14. Coatings for transport industry

    Directory of Open Access Journals (Sweden)

    Krzysztof LUKASZKOWICZ

    2014-09-01

    Full Text Available The investigations concerned structural analysis, as well as mechanical properties and wear resistant of MeN/DLC double-layer coating deposited by hybrid PVD/PACVD method. In sliding dry friction conditions, after the break-in time, the friction coefficient for the investigated elements is set in the range between 0.03-0.06.

  15. The Spore Coat.

    Science.gov (United States)

    Driks, Adam; Eichenberger, Patrick

    2016-04-01

    Spores of Clostridiales and Bacillales are encased in a complex series of concentric shells that provide protection, facilitate germination, and mediate interactions with the environment. Analysis of diverse spore-forming species by thin-section transmission electron microscopy reveals that the number and morphology of these encasing shells vary greatly. In some species, they appear to be composed of a small number of discrete layers. In other species, they can comprise multiple, morphologically complex layers. In addition, spore surfaces can possess elaborate appendages. For all their variability, there is a consistent architecture to the layers encasing the spore. A hallmark of all Clostridiales and Bacillales spores is the cortex, a layer made of peptidoglycan. In close association with the cortex, all species examined possess, at a minimum, a series of proteinaceous layers, called the coat. In some species, including Bacillus subtilis, only the coat is present. In other species, including Bacillus anthracis, an additional layer, called the exosporium, surrounds the coat. Our goals here are to review the present understanding of the structure, composition, assembly, and functions of the coat, primarily in the model organism B. subtilis, but also in the small but growing number of other spore-forming species where new data are showing that there is much to be learned beyond the relatively well-developed basis of knowledge in B. subtilis. To help summarize this large field and define future directions for research, we will focus on key findings in recent years.

  16. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...

  17. Durable superhydrophobic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, John T.; Polyzos, Georgios; Schaeffer, Daniel A.

    2017-11-28

    A superhydrophobic coating including a plurality of particles and a resin. The particles covalently bond to the resin and the resin does not fill the pores of the superhydrophobic particles such that the three dimensional surface topology of the superhydrophobic particles is preserved.

  18. REFRACTORY COATING FOR GRAPHITE MOLDS

    Science.gov (United States)

    Stoddard, S.D.

    1958-06-24

    Refractory coating for graphite molds used in the casting of uranium is described. The coating is an alumino-silicate refractory composition which may be used as a mold surface in solid form or as a coating applied to the graphite mold. The composition consists of a mixture of ball clay, kaolin, alumina cement, alumina, water, sodium silicate, and sodium carbonate.

  19. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, L. M.; Hintze, P. E.; Li, W.; Buhrow, J. W.; Jolley, S. T.

    2011-01-01

    This slide presentation reviews the effects of corrosion on various structures at the Kennedy Space Center, and the work to discover a corrosion control coating that will be autonomous and will indicate corrosion at an early point in the process. Kennedy Space Center has many environmental conditions that are corrosive: ocean salt spray, heat, humidity, sunlight and acidic exhaust from the Solid Rocket Boosters (SRBs). Presented is a chart which shows the corrosion rates of carbon steel at various locations. KSC has the highest corrosion rates with 42.0 mils/yr, leading the next highest Galeta Point Beach, in the Panama Canal Zone with 27 mils/yr corrosion. A chart shows the changes in corrosion rate with the distance from the ocean. The three types of corrosion protective coatings are described: barrier (passive), Barrier plus active corrosion inhibiting components, and smart. A smart coating will detect and respond actively to changes in its environment in a functional and predictable manner and is capable of adapting its properties dynamically. The smart coating uses microcapsules, particles or liquid drops coated in polymers, that can detect and control the corrosion caused by the environment. The mechanism for a pH sensitive microcapsule and the hydrophobic core microcapsule are demonstrated and the chemistry is reviewed. When corrosion begins, the microcapsule will release the contents of the core (indicator, inhibitor, and self healing agent) in close proximity to the corrosion. The response to a pH increase is demonstrated by a series of pictures that show the breakdown of the microcapsule and the contents release. An example of bolt corrosion is used, as an example of corrosion in places that are difficult to ascertain. A comparison of various coating systems is shown.

  20. A Multiple-Action Self-Healing Coating

    Directory of Open Access Journals (Sweden)

    Alexander eLutz

    2016-01-01

    Full Text Available This paper describes a self-healing coating for corrosion protection of metals which combines two different types of self-healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT was loaded into layered double hydroxide (LDH carriers which were mixed into an acrylated polycaprolactone polyurethane based shape recovery coating and applied on Hot Dip Galvanized steel (HDG. The effect of triggered release of MBT on the protection of HDG became visible when samples with manually applied defects in the coating were immersed in 0.05 M NaCl solution (first, autonomous healing mechanism. The shape recovery (second, non-autonomous healing mechanism was triggered by heating the samples for 2 minutes to 60°C. SEM-EDX and Raman Spectroscopy proved the presence of MBT in the LDH, in the MBT-loaded LDH in the coating and the released MBT on the HDG surface in the damaged area after being in contact with a solution containing corrosive ions. Electrochemical impedance spectroscopy (EIS and scanning vibrating electrode technique (SVET demonstrate the corrosion protection effect of MBT in the coating with a defect and the restoration of the barrier properties of the coating after defect closure. This way, the independent mechanisms of this multi-action self-healing coating could be demonstrated.

  1. A Multiple-Action Self-Healing Coating

    Science.gov (United States)

    Lutz, Alexander; van den Berg, Otto; Wielant, Jan; De Graeve, Iris; Terryn, Herman

    2015-12-01

    This paper describes a self-healing coating for corrosion protection of metals which combines two different types of self-healing mechanisms in one coating with multiple-healing functionality. 2-Mercaptobenzothiazole (MBT) was loaded into layered double hydroxide (LDH) carriers which were mixed into an acrylated polycaprolactone polyurethane based shape recovery coating and applied on Hot Dip Galvanized steel (HDG). The effect of triggered release of MBT on the protection of HDG became visible when samples with manually applied defects in the coating were immersed in 0.05 M NaCl solution (first, autonomous healing mechanism). The shape recovery (second, non-autonomous healing mechanism) was triggered by heating the samples for 2 minutes to 60°C. SEM-EDX and Raman Spectroscopy proved the presence of MBT in the LDH, in the MBT-loaded LDH in the coating and the released MBT on the HDG surface in the damaged area after being in contact with a solution containing corrosive ions. Electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET) demonstrate the corrosion protection effect of MBT in the coating with a defect and the restoration of the barrier properties of the coating after defect closure. This way, the independent mechanisms of this multi-action self-healing coating could be demonstrated.

  2. Possibilities of utilization high velocity oxygen fuel (HVOF coatings in conditions of thermal cyclic loading

    Directory of Open Access Journals (Sweden)

    J. Brezinová

    2012-04-01

    Full Text Available The item deals with the possibilities of utilization HVOF coatings in thermal cyclic loading conditions. There were evaluated three types of coatings based on WC-Co, WC-Co-Cr and Cr3C2-25NiCr. The quality of coatings was evaluated in terms of their adhesion as sprayed and also during the cyclic thermal loading, EDX analysis and evaluation of microhardness. Construction and structure of coatings were studied using optical and electron microscopy. There was also evaluated resistance of the coatings against erosive wear.

  3. Benchmarking of Zinc Coatings for Corrosion Protection: A Detailed Characterization of Corrosion and Electrochemical Properties of Zinc Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, Sudesh L; Zixi, Tan [Singapore Institute of Manufacturing Technology, Nanyang Drive (Singapore)

    2017-02-15

    Due to various types of Zn coatings for many decades for various applications, it is imperative to study and compare their corrosion resistance properties of some of these. Here, we introduce a systematic methodology for evaluation and validation of corrosion protection properties of metallic coatings. According to this methodology, samples are were exposed in an advanced cyclic corrosion test chamber according to ISO 14993, and removed at the end of each withdrawal for respective corrosion and electrochemical characterization to evaluate both barrier and galvanic protection properties. Corrosion protection properties of coatings were evaluated by visual examination according to ISO 10289, mass loss and subsequent corrosion rate measurements, electrochemical properties, and advanced electrochemical scanning techniques. In this study, corrosion protection properties of a commercial zinc rich coating (ZRC) on AISI 1020 mild steel substrates were evaluated and benchmarked against hot dip galvanized (HDG). Results were correlated, and corrosion protection capabilities of the two coatings were compared. The zinc rich coating performed better than hot dip galvanized coating in terms of overall corrosion protection properties, according to the exposure and experimental conditions used in this study. It proved to be a suitable candidate to replace hot dip galvanized coatings for desired applications.

  4. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    2014-09-26

    1ITLE AND SUBTITLE 5a CONTRACTNUMBER Architecture and assembly of the Bacillus subtilis spore coat W911NF-09-l-0286 5b. GRANT NUMBER 5c. PROGRAM...ABSTRACT In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild-type and cotA, cotB, safA, cotH...Std. Z39.18 ABSTRACT Architecture and assembly of the Bacillus subtilis spore coat Report Title In this study, atomic force microscopy was used to

  5. Effect of heat treatment, top coatings and conversion coatings on the corrosion properties of black electroless Ni-P films

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y., E-mail: liu_yunli@hotmail.com [R and D Department, MacDermid plc, 198 Golden Hillock Road, Birmingham B11 2PN (United Kingdom); Beckett, D.; Hawthorne, D. [R and D Department, MacDermid plc, 198 Golden Hillock Road, Birmingham B11 2PN (United Kingdom)

    2011-02-15

    Electroless black nickel-phosphorus plating is an advanced electroless nickel plating process formulated to deposit a black finish when processed through an oxidizing acid solution. Heat treatment, five types of top organic coating techniques and one conversion coating technique with three different experimental conditions were investigated to stabilize the black film and increase the hardness and corrosion resistance. Morphology and compositions of electroless nickel-phosphorous films with or without heat treatment, with five types of top organic coatings, and with three conversion coatings were compared to examine nickel, phosphorus, oxygen, carbon, silicon and chrome contents on the corrosion resistance of black surfaces by energy dispersive X-ray microanalysis and scanning electron microscope. Corrosion resistance of black electroless nickel-phosphorus coatings with or without heat treatment, with five types of top organic coatings, and with three conversion coatings was investigated by the polarization measurements and the salt spray test in 5% NaCl solution, respectively. HydroLac as the top organic coating from MacDermid showed the excellent corrosion resistance and the black EN film did not lose the black color after 48 h salt spray test. Electrotarnil B process with 0.5 ASD for 1 min stabilized the black Ni-P film immediately and increased the hardness and corrosion performance of the black Ni-P film. The black Ni-P coating with Electroarnil B process passed the 5% NaCl salt spray test for 3000 h in the black color and had a minimal corrosion current 0.8547 {mu}A/cm{sup 2} by the polarization measurement.

  6. Colon-specific drug delivery using ethylcellulose and chitosan in the coat of compression-coated tablets.

    Science.gov (United States)

    Omwancha, Wycliffe; Kouba, Chahinaz; Yelamanchili, Satish; Neau, Steven H

    2011-08-01

    This study investigates a new means to achieve colon-specific drug delivery. This study assesses the use of chitosan and ethylcellulose in the coat of a compression-coated tablet to achieve colon-specific drug delivery. The effects of chitosan type and its level as well as the coat thickness were evaluated. Caffeine-containing core tablets were prepared by direct compression. Three chitosan samples with different molecular weight and degree of deacetylation were used. Direct compression produced the finished coated tablet. The product was tested for its potential in colon-specific drug delivery by conducting release studies in simulated gastric and intestinal fluids. Enzymes harvested from rat cecal and colonic contents contributed to a medium to study drug release under colonic conditions. Essentially no drug was released until action on the tablet by either the acidic pH or the presence of enzymes in the release medium. Chitosan type had no effect on drug release as long as the coating level was the same. Lowering the chitosan level in the coat or increasing the coat thickness increased the lag time. The type of chitosan can be changed and yet the product is still susceptible to enzyme or pH effects. This indicates that chitosan present in the coat is still available for such action by the release medium. One can control the chitosan level or the thickness of the coat to achieve a desired delivery profile. As colonic media can dramatically promote drug release, the potential for colon-specific drug delivery is confirmed.

  7. Intralesional autotherapy of cutaneous leishmaniasis with buffy coat cells: cytological findings

    DEFF Research Database (Denmark)

    Dabiri, S; Meymandi, S S; Hayes, M M

    2000-01-01

    The skin lesions of five patient volunteers with dry-type cutaneous leishmaniasis were treated by intralesional injection of auto-leukocytes prepared from buffy coat of the patient's own blood. Giemsa stained, air-dried cytological smear preparations were prepared from scrapings taken from...... the potential for intralesional autotherapy with buffy coat in dry-type cutaneous leishmaniasis....

  8. Methods for Coating Particulate Material

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2013-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  9. Ultrasonic Coating and Holographic Exposure Technology. Phase 1

    Science.gov (United States)

    2015-09-01

    distribution of droplet number density across the width of spray. The central droplets coalesce , but the boundary droplets do not. The coating...some aspects, including atomization process, dynamics of mechanical deformation/ coalescence of droplets and their size distribution, this type of...examination. More droplet coalescence was observed for AZB coating, which suggested that the liquid might contain slower evaporating solvent. Figure 91-93

  10. Advances in Protective Coatings and Their Application to Ageing Aircraft

    Science.gov (United States)

    2000-04-01

    removed used a comparatively preparation and increased chemical resistance. This is simple paint stripper . reflected in differences in the condition...possible alternatives selected because of its high resistance to fluids. The only to cadmium plating. chemical paint strippers , which are effective on...these types of coating, are based on methylene chloride with additives of Fig.3 compares the corrosion of several zinc alloy coatings phenol. These are

  11. FY 1998 report on the results of the venture promotion type regional consortium- small-/medium-size enterprise creation base type. consortiums. Development of photo-curing containing coating materials for comfortable, healthy indoor environments; 1998 nendo shitsunai kankyo no kaitekisei, kenkosei ni taioshita hikari jugo urushi toryo no kaihatsu seika hokokusho. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This research and development project is aimed at activation of the urushi industry and creation of the new business by utilizing the natural material by the name of urushi solution as the functional coating material satisfying the various conditions required for the coating solutions of the next generation, e.g., healthy, safety, comfortable and environmentally harmless characteristics. The urushi solution developed by this project is an innovative, creative one, which solves the major problems involved in the conventional solution, i.e., slow curing and causing eruption of the skin, by enzyme-aided polymerization and photopolymerization. The physiological activities of the urushi solution component and antimicrobial effects by the urushi layer, which are considered to be the potential functions of urushi, are also investigated for the project. The urushi-containing UV coating material means an ultraviolet-curable urushi/synthetic resin material, composed of refined urushi, a photopolymerizable acrylate compound and photopolymerization initiator. The refined urushi for the urushi-containing UV coating material can be adjusted for its degree of polymerization, as found by the experimental investigation of the catalyst for accelerating enzyme-aided polymerization, to improve curability. The confirmed physiological activities of the urushi component are accelerated solidification of the blood and manifestation of the anti-HIV function. The coating film of the refined urushi is found to be effective against Bacillus coli and Staphylococcus aureus. (NEDO)

  12. Effect of Molybdenum on the Microstructures and Properties of Stainless Steel Coatings by Laser Cladding

    Directory of Open Access Journals (Sweden)

    Kaiming Wang

    2017-10-01

    Full Text Available Stainless steel powders with different molybdenum (Mo contents were deposited on the substrate surface of 45 steel using a 6 kW fiber laser. The microstructure, phase, microhardness, wear properties, and corrosion resistance of coatings with different Mo contents were studied by scanning electron microscopy (SEM, electron probe microanalyzer (EPMA, X-ray diffraction (XRD, microhardness tester, wear tester, and electrochemical techniques. The results show that good metallurgical bonding was achieved between the stainless steel coating and the substrate. The amount of M7(C, B3 type borocarbide decreases and that of M2B and M23(C, B6 type borocarbides increases with the increase of Mo content in the coatings. The amount of martensite decreases, while the amount of ferrite gradually increases with the increase of Mo content. When the Mo content is 4.0 wt. %, Mo2C phase appears in the coating. The microstructure of the coating containing Mo is finer than that of the Mo-free coating. The microhardness decreases and the wear resistance of the coating gradually improves with the increase of Mo content. The wear resistance of the 6.0 wt. % Mo coating is about 3.7 times that of the Mo-free coating. With the increase of Mo content, the corrosion resistance of the coating firstly increases and then decreases. When the Mo content is 2.0 wt. %, the coating has the best corrosion resistance.

  13. Analysis of metal surfaces coated with europium-doped titanium dioxide by laser induced breakdown spectroscopy.

    Science.gov (United States)

    Głogocka, Daria; Noculak, Agnieszka; Pucińska, Joanna; Jopek, Wojciech; Podbielska, Halina; Langner, Marek; Przybyło, Magdalena

    2015-01-01

    The surface passivation with titanium sol-gel coatings is a frequently used technique to control the adsorption of selected biological macromolecules and to reduce the exposure of the bulk material to biological matter. Due to the increasing number of new coating-preparation methods and new gel compositions with various types of additives, the quality and homogeneity determination of the surface covering is a critical factor affecting performance of any implanted material. While coating thickness is easy to determine, the homogeneity of the surface distribution of coating materials requires more elaborate methodologies. In the paper, the laser induced breakdown spectroscopy (LIBS) based method, capable to quantitate the homogeneity and uniformity of the europium in titanium dioxide sol-gel coatings on stainless steel surfaces prepared with two different procedures: spin-coating and dip-coating, is presented. The emission intensity of titanium has been used to determine the coating thickness whereas the relative values of europium and titanium emission intensities provide data on the coating homogeneity. The obtained results show that the spin-coating technique provides better surface coverage with titanium dioxide. However, when the surface coating compositions were compared the dip-coating technique was more reliable.

  14. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  15. High Solids Coating System

    Science.gov (United States)

    1979-04-01

    36622 Aircraft Gray No, 3� Dark Green No 30219 Tan No 17875 Tnsignia White D. Applicat ion In addition to conventionl . air ,3pray, evaluation of...requirements are 60% for gloss colors and 20% for camouflage colors. Adhesion of the coating to the elongated surfaces was evaluated by placing 250 masking...tape (3M) to the surface, insuring adhesion and then removing with one abrupt pull. Any paintI removal constitutes failure. 2. Heat Resistance Test

  16. The formation of calcium phosphate coatings by pulse laser deposition on the surface of polymeric ferroelectric

    Energy Technology Data Exchange (ETDEWEB)

    Bolbasov, E.N. [Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050 (Russian Federation); Lapin, I.N.; Svetlichnyi, V.A. [Tomsk State University, 36 Lenin Avenue, Tomsk 634050 (Russian Federation); Lenivtseva, Y.D. [Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050 (Russian Federation); Malashicheva, A. [Federal Almazov Medical Research Centre, 2 Akkuratova St., St. Petersburg 197341 (Russian Federation); St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034 (Russian Federation); ITMO University, Institute of translational Medicine, St. Petersburg (Russian Federation); Malashichev, Y. [St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034 (Russian Federation); Golovkin, A.S. [Federal Almazov Medical Research Centre, 2 Akkuratova St., St. Petersburg 197341 (Russian Federation); Anissimov, Y.G. [Griffith University, School of Natural Sciences, Engineering Dr., Southport, QLD 4222 (Australia); Tverdokhlebov, S.I., E-mail: tverd@tpu.ru [Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050 (Russian Federation)

    2015-09-15

    Graphical abstract: - Highlights: • Calcium phosphate coatings were obtained on ferroelectric polymer materials surface by using PLD method. • Obtained coatings have well-developed surface. • Depending on sputtering target composition it is possible to obtain crystalline or amorphous coating. • Formation of coating does not change the crystal structure of the ferroelectric polymer material. - Abstract: This work analyses the properties of calcium phosphate coatings obtained by pulsed laser deposition on the surface of the ferroelectric polymer material. Atomic force and scanning electron microscopy studies demonstrate that, regardless of the type of sputtering target, the calcium phosphate coatings have a multiscale rough surface that is potentially capable of promoting the attachment and proliferation of osteoblasts. This developed surface of the coatings is due to its formation mainly from a liquid phase. The chemical and crystalline composition of the coatings depends on the type of sputtering target used. It was shown that, regardless of the type of sputtering target, the crystalline structure of the ferroelectric polymer material does not change. Cell viability and adhesion studies of mesenchymal stromal cells on the coatings were conducted using flow cytometry and fluorescent microscopy. These studies indicated that the produced coatings are non-toxic.

  17. Lotus Dust Mitigation Coating and Molecular Adsorber Coating

    Science.gov (United States)

    O'Connor, Kenneth M.; Abraham, Nithin S.

    2015-01-01

    NASA Goddard Space Flight Center has developed two unique coating formulations that will keep surfaces clean and sanitary and contain contaminants.The Lotus Dust Mitigation Coating, modeled after the self-cleaning, water-repellant lotus leaf, disallows buildup of dust, dirt, water, and more on surfaces. This coating, has been successfully tested on painted, aluminum, glass, silica, and some composite surfaces, could aid in keeping medical assets clean.The Molecular Adsorber Coating is a zeolite-based, sprayable molecular adsorber coating, designed to prevent outgassing in materials in vacuums. The coating works well to adsorb volatiles and contaminates in manufacturing and processing, such as in pharmaceutical production. The addition of a biocide would also aid in controlling bacteria levels.

  18. Corrosion Resistance of Electroless Ni-Cu-P Ternary Alloy Coatings in Acidic and Neutral Corrosive Mediums

    OpenAIRE

    Mbouillé Cissé; Mohamed Abouchane; Tayeb Anik; Karima Himm; Rida Allah Belakhmima; Mohamed Ebn Touhami; Rachid Touir; Abderrahmane Amiar

    2010-01-01

    Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hypophosphite-type plating bath. These coatings were characterized by a scanning electron microscope (SEM) and an X-ray diffraction. The micrograph shows that coating presents a nodular aspect and is relatively homogeneous and very smooth. The EDX analysis shows that the coating contains 12 wt.% of phosphorus element with a predominance of nickel element. In addition, the anticorrosion properties of...

  19. A Study on the Exploration of Electrostatic Powder Coating Materials Suitable for 3D Scanning

    Directory of Open Access Journals (Sweden)

    Maeng Hee-young

    2016-01-01

    Full Text Available There are many difficulty in collecting data from a diffused reflection surface using an optical 3D scanning device. A spray-type developer and silicon molds are used for solving this problem. However, using developer can cause chemical reactions between objects and developer particles and uneven surfaces of the object. To overcome these problems, it is suggested an electrostatic powder coating method for even coating of particles onto surfaces for collecting 3D shape data. We have developed an automatic, electrostatic powder coating machine. The present study is aimed to explore powder materials suitable for electrostatic powder coating in terms of the easiness of coating work considering the characteristics of object surface. It was also conducted to verify materials that are smoothly coated well under various coating conditions and are advantageous in collecting 3D shape data.

  20. Biocompatibly Coated 304 Stainless Steel as Superior Corrosion-Resistant Implant Material to 316L Steel

    Science.gov (United States)

    Paul, Subir; Mandal, Chandranath

    2013-10-01

    Surface treatments of 304 stainless steel by electro-coating and passivating in few inorganic electrolytes were found to be very effective in drastically reducing the corrosion rate of the material in stimulated body fluid (SBF) by several orders in comparison to that of 316L steel, presently being used for orthopedic implants. Polarization studies of electrodeposited hydroxyl apatite coating on 304 steel showed remarkably improved corrosion current. Cyclic polarization of the material in SBF reflected the broadened passivity region, much lower passive current, and narrower hysteresis loops. Similar effects were also found through the formation of inorganic coatings by passivation in NaF, CaNO3, and calcium phosphate buffer solutions. Surface characterization by XRD showed the peaks of the respective coating crystals. The morphology of the coatings studied by SEM showed a flake-type structure for hydroxyapatite coating and fine spherical-subspherical particles for other coatings.

  1. Friction and wear resistance of the electroless Ni-P-CNTs composite coatings

    Science.gov (United States)

    Zhao, G.; Zhang, H.; Wang, Z.

    2007-07-01

    Ni-P-Carbon nanotubes (CNTs) composite coatings as well as Ni-P-SiC and Ni-P coatings were prepared by electroless plating. The characteristics of the coatings were assessed by scanning electron microscopy and microhardness test. The friction and wear performance of the produced composite coatings were investigated at room temperature on a ball-on-disc type tribometer under non-lubricated conditions. The results show that the Ni-P-CNTs composite coatings exhibited lowed friction coefficient and better anti-wear performance compared to Ni-P-SiC and Ni-P coatings due to improved mechanical properties, self-lubrication and unique microstructure of the Ni-P-CNTs composite coatings. The effect of CNTs on the friction and wear resistance was discussed in detail.

  2. Influence of coating defects on the corrosion behavior of cold sprayed refractory metals

    Science.gov (United States)

    Kumar, S.; Rao, A. Arjuna

    2017-02-01

    The defects in the cold sprayed coatings are critical in the case of corrosion performances of the coatings in aggressive conditions. To understand the influence of coating defects on corrosion, immersion tests have been carried out in HF solution for the cold sprayed and heat treated Titanium, Tantalum and Niobium coatings. Long duration immersion tests reveal inhomogeneous weight losses of the samples prepared at different heat treatment conditions. The weight loss for different coatings has been well corroborated with the coating defects and microstructures. Chemical and micro structural analysis elucidates the reason behind the inhomogeneous performance of different type of cold sprayed coatings in corrosion medium. In the case of cold sprayed titanium, formation of stable oxide along the inter-splat boundary hinders the aggressive attack of the corrosion medium which is not so in other cases.

  3. Hydrothermal durability of Ca-complexed methylmethacrylate-trimethylolpropane trimethacrylate copolymer films and coatings containing superficially formed CaO-SiO/sub 2/-H/sub 2/O type inorganic macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T.; Kukacka, L.E.

    1983-12-01

    A CaO-SiO/sub 2/-H/sub 2/O macromolecular-ionomer complex was found to be formed in the superficial layers of MMA-TMPTMA copolymer composite films made with filler containing hydraulic cement during exposure in an autoclave at temperatures up to 200/sup 0/C. This superficially formed complex in terms of self-healing protective layers, acted to prevent the hydrothermal deterioration of the original composite films, which is important if the films are used as protective layers on metals. Studies of the adhesion of the complex composite coatings to chemically treated metal surfaces were also performed. It was found that the surface topography of hopeite crystalline layers results in an increase in wetting forces and mechanical interlocking forces.

  4. Tribology of polymeric coatings for aggressive bearing applications

    Science.gov (United States)

    Yeo, Seung Min

    To meet the higher performance requirements of today's air-conditioning and refrigeration (ACR) compressors, their operating conditions have been getting harsher under higher speed and load, thus making tribological characteristics of interacting surfaces playing a significant role in compressor's reliability. However, the capabilities of conventional fluid lubricants are limited such that the state of lubrication is usually unknown, and, at best, in the boundary/mixed lubrication regimes. Therefore, it becomes necessary to implement some type of advanced protective coatings on the interacting surfaces to withstand stringent contact conditions. Due to favorable tribological performance, polytetrafluoroethylene (PTFE)- and polyetheretherketone (PEEK)-based polymeric coatings have received interest in ACR compressor applications, as a potential solution to supplement and potentially replace conventional oil lubricants. However, compared to a great amount of research and experiments done so far for bulk of polymers, there is limited literature on the tribological performance of PTFE- and PEEK-based polymeric coatings. In this work, several PTFE-, PEEK-, resin- and fluorocarbon-based polymeric coatings, coated on gray cast iron were tribologically evaluated using a specialized tribometer under compressor specific conditions. The coatings showed good to excellent tribological performance, and in general PTFE-based coatings exhibited better friction and wear behavior than the rest of the coatings, including PEEK-based coatings. The micromechanical properties of polymeric coatings were examined using instrumented microindentation. The load-unload responses were used to measure the load-bearing properties of the coatings, as well as to extract their elastic modulus and hardness values. Induced structural differences between the PTFE- and PEEK-based coatings were confirmed using scanning electron microscopy. These measurements were used to explain the difference in the

  5. Nanoparticle/Polymer Nanocomposite Bond Coat or Coating

    Science.gov (United States)

    Miller, Sandi G.

    2011-01-01

    This innovation addresses the problem of coatings (meant to reduce gas permeation) applied to polymer matrix composites spalling off in service due to incompatibility with the polymer matrix. A bond coat/coating has been created that uses chemically functionalized nanoparticles (either clay or graphene) to create a barrier film that bonds well to the matrix resin, and provides an outstanding barrier to gas permeation. There is interest in applying clay nanoparticles as a coating/bond coat to a polymer matrix composite. Often, nanoclays are chemically functionalized with an organic compound intended to facilitate dispersion of the clay in a matrix. That organic modifier generally degrades at the processing temperature of many high-temperature polymers, rendering the clay useless as a nano-additive to high-temperature polymers. However, this innovation includes the use of organic compounds compatible with hightemperature polymer matrix, and is suitable for nanoclay functionalization, the preparation of that clay into a coating/bondcoat for high-temperature polymers, the use of the clay as a coating for composites that do not have a hightemperature requirement, and a comparable approach to the preparation of graphene coatings/bond coats for polymer matrix composites.

  6. Dense protective coatings, methods for their preparation and coated articles

    Science.gov (United States)

    Tulyani, Sonia; Bhatia, Tania; Smeggil, John G.

    2015-12-29

    A method for depositing a protective coating on a complex shaped substrate includes the steps of: (1) dipping a complex shaped substrate into a slurry to form a base coat thereon, the slurry comprising an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; (2) curing the dipped substrate; (3) dipping the substrate into a precursor solution to form a top barrier coat thereon; and (4) heat treating the dipped, cured substrate to form a protective coating.

  7. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  8. Design and simulation of thermal residual stresses of coatings on WC-Co cemented carbide cutting tool substrate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Anhai; Zhao, Jun; Zang, Jian; Zheng, Wei [Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE, School of Mechanical EngineeringShandong University, Jinan (China)

    2016-08-15

    Large thermal residual stresses in coatings during the coating deposition process may easily lead to coating delamination of coated carbide tools in machining. In order to reduce the possibility of coating delamination during the tool failure process, a theoretical method was proposed and a numerical method was constructed for the coating design of WC-Co cemented carbide cutting tools. The thermal residual stresses of multi-layered coatings were analytically modeled based on equivalent parameters of coating properties, and the stress distribution of coatings are simulated by Finite element method (FEM). The theoretically calculated results and the FEM simulated results were verified and in good agreement with the experimental test results. The effects of coating thickness, tool substrate, coating type and interlayer were investigated by the proposed geometric and FEM model. Based on the evaluations of matchability of tool substrate and tool coatings, the basic principles of tool coating design were proposed. This provides theoretical basis for the selection and design of coatings of cutting tools in high-speed machining.

  9. Tablet coating by injection molding technology - Optimization of coating formulation attributes and coating process parameters.

    Science.gov (United States)

    Desai, Parind M; Puri, Vibha; Brancazio, David; Halkude, Bhakti S; Hartman, Jeremy E; Wahane, Aniket V; Martinez, Alexander R; Jensen, Keith D; Harinath, Eranda; Braatz, Richard D; Chun, Jung-Hoon; Trout, Bernhardt L

    2018-01-01

    We developed and evaluated a solvent-free injection molding (IM) coating technology that could be suitable for continuous manufacturing via incorporation with IM tableting. Coating formulations (coating polymers and plasticizers) were prepared using hot-melt extrusion and screened via stress-strain analysis employing a universal testing machine. Selected coating formulations were studied for their melt flow characteristics. Tablets were coated using a vertical injection molding unit. Process parameters like softening temperature, injection pressure, and cooling temperature played a very important role in IM coating processing. IM coating employing polyethylene oxide (PEO) based formulations required sufficient room humidity (>30% RH) to avoid immediate cracks, whereas other formulations were insensitive to the room humidity. Tested formulations based on Eudrajit E PO and Kollicoat IR had unsuitable mechanical properties. Three coating formulations based on hydroxypropyl pea starch, PEO 1,000,000 and Opadry had favorable mechanical (35% elongation, >95×10 4 J/m 3 toughness) and melt flow (>0.4g/min) characteristics, that rendered acceptable IM coats. These three formulations increased the dissolution time by 10, 15 and 35min, respectively (75% drug release), compared to the uncoated tablets (15min). Coated tablets stored in several environmental conditions remained stable to cracking for the evaluated 8-week time period. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 100% Solids Polyurethane Sequestration Coating

    Science.gov (United States)

    2014-04-11

    section of an aluminum flake loaded thiol-ene coating peeled off of a glass plate after cure. Adsorbents and Reactive Particles Nanoparticulate ...commercially to the oil drilling industry. The incorporation of CaCO3 nanoparticulate into thiol-ene coatings was demonstrated in our Phase I project...Porous, nanoparticulate SiO2 has also been identified and evaluated in coating systems. The effect of high capacity adsorbents on permeation through

  11. The removal torque of titanium implant inserted in rabbit femur coated with biomimetic deposited Ca-P coating.

    Science.gov (United States)

    Fuming, H; Guoli, Y; Xiaoxiang, W; Shifang, Z

    2008-10-01

    A number of experimental data on biomimetic deposition CaP (BDCaP) coating implants have reported promising outcomes by histological evaluation. But little is investigated on the role of the BDCaP coating and osseointegration mechanism by interface shear strength. To make a direct biomechanical comparison between the BDCaP coating implants and the uncoated rough titanium implants (control), a well-established animal model for implants removal torque testing was employed in rabbits, using a self-matching experimental design. All implants had an identical cylindrical screw shape without any macroscopic retentive structure. After 2, 4, 6, 8 and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each implant type. The torqued implants were sputter-coated with gold for morphology observation and observed with a field-emission electron microscopy. Results showed that the interfacial shear strength of the BDCaP coating implants was similar to that of the uncoated rough implants at 2 and 4 weeks of healing. The mean removal torque values of the BDCaP coating implants were lower than those of control implants (P 0.05). It can be concluded that the BDCaP coating implants had no beneficial effect on the interfacial shear strength at early bone healing stage.

  12. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  13. Axisymmetric fretting analysis in coated cylinder

    Indian Academy of Sciences (India)

    erties by coating the surface. There is rather scanty literature available on fretting analysis of coated components. Presence of such coatings has a large influence on the near surface state of stress. The effect of coatings on the severity of fretting is the focus of this paper. Results obtained for both hard and soft coatings are ...

  14. Coatings Technology Integration Office (CTIO)

    Data.gov (United States)

    Federal Laboratory Consortium — CTIO serves as the Air Force's central resource for aircraft coating systems and their applications. CTIO's primary objectives are pollution prevention and improved...

  15. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  16. Electrochemically switchable polypyrrole coated membranes

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, Claudia, E-mail: weidlich@dechema.d [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany); Mangold, Klaus-Michael [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany)

    2011-04-01

    A method for coating membranes with polypyrrole (PPy) has been developed. Different membranes, such as microfiltration as well as ion exchanger membranes have been coated with PPy to yield electrical conductivity of the membranes. The coated membranes have been investigated by cyclic voltammetry and scanning electron microscopy and their permeability and permselectivity have been tested. The results show that PPy can be tailored as cation or anion exchanger and its porosity can be controlled to avoid any impairment of the membrane by the polymer layer. These PPy coated membranes can be applied as electrochemically switchable, functionalised membranes with controllabel and variable separation properties.

  17. The effect of salivary pH on diametral tensile strength of resin modified glass ionomer cement coated with coating agent

    Science.gov (United States)

    Ismayanti, D.; Triaminingsih, S.; Eriwati, Y. K.

    2017-08-01

    The aim of this study was to evaluate the effect of artificial saliva with different acidities on the diametral tensile strength of Resin Modified Glass Ionomer Cement (RMGIC) coated with varnish and nanofilled coating agent. The specimens coated with coating agents were immersed in artificial saliva with pH of 4.5, 5.5, and 7 for 24 hours in an incubatorat 37°C. The diametral tensile strength of the specimens was tested with Universal Testing Machine. There were no significant differences on the diametral tensile strength of all specimens that were put into groups based on the acidity of the saliva and the type of coating agent (p>0.05). Both varnish and nanofilled coating agent stayed on the RMGIC in the acidic condition that simulated the true condition of oral cavity in people with high caries risk for the 24 hours of maturation.

  18. Diamond coated silicon field emitter array

    Energy Technology Data Exchange (ETDEWEB)

    S. Albin; W. Fu; A. Varghese; A. C. Lavarias; G. R. Myneni

    1999-07-01

    Diamond coated silicon tip arrays, with and without a self-aligned gate, were fabricated, and current-voltage characteristics of 400 tips were measured. Diamond films were grown uniformly on Si tips using microwave plasma after nucleation with 10 nm diamond suspension and substrate bias. An emission current of 57 ?A was obtained at 5 V from the ungated array tips separated from an anode at 2 ?m. In the case of the gated arrays with 1.5 ?m aperture, an emission current of 3.4 ?A was measured at a gate voltage of 80 V for an anode separation of 200 ?m. The turn-on voltages for these two types of devices were 0.2 and 40 V, respectively. Diamond coated Si tip arrays have potential applications in field emission based low voltage vacuum electronic devices and microsensors.

  19. Research Progress on Laser Cladding Amorphous Coatings on Metallic Substrates

    Directory of Open Access Journals (Sweden)

    CHEN Ming-hui

    2017-01-01

    Full Text Available The microstructure and property of amorphous alloy as well as the limitations of the traditional manufacturing methods for the bulk amorphous alloy were briefly introduced in this paper.Combined with characteristics of the laser cladding technique,the research status of the laser cladding Fe-based,Zr-based,Ni-based,Cu-based and Al-based amorphous coatings on the metal substrates were mainly summarized.The effects of factors such as laser processing parameter,micro-alloying element type and content and reinforcing phase on the laser cladding amorphous coatings were also involved.Finally,the main problems and the future research directions of the composition design and control of the laser-cladded amorphous coating,the design and optimization of the laser cladding process,and the basic theory of the laser cladding amorphous coatings were also put forward finally.

  20. Polysaccharide-Coated Magnetic Nanoparticles for Imaging and Gene Therapy

    Directory of Open Access Journals (Sweden)

    Saji Uthaman

    2015-01-01

    Full Text Available Today, nanotechnology plays a vital role in biomedical applications, especially for the diagnosis and treatment of various diseases. Among the many different types of fabricated nanoparticles, magnetic metal oxide nanoparticles stand out as unique and useful tools for biomedical applications, because of their imaging characteristics and therapeutic properties such as drug and gene carriers. Polymer-coated magnetic particles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials. Theranostic magnetic nanoparticles that are encapsulated or coated with polymers not only exhibit imaging properties in response to stimuli, but also can efficiently deliver various drugs and therapeutic genes. Even though a large number of polymer-coated magnetic nanoparticles have been fabricated over the last decade, most of these have only been used for imaging purposes. The focus of this review is on polysaccharide-coated magnetic nanoparticles used for imaging and gene delivery.

  1. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  2. Durable Hybrid Coatings

    Science.gov (United States)

    2007-10-01

    rich primers at 32% and 42% PVC. PVC Epon 828 (g) Epicure 2353 (g) MEK (g) Mg and Mg alloy Pigments (g) 3820 AM60 AZ91B LNR96 AM503 AZG...vol. ratio. Epon 1001-CX-75 is an epoxide containing 25 wt.% MIBK/xylene (vol. ratio 65/35) solvent mixture, and Epicure 3140 is a solventless...μm. Table 1. Formulation of Mg-rich Primer Coating Ingredients Weight, g Epon 1001-CX-75 67 111 Epicure 3140 9.5 Mg powder 95 Aerosil® R974 1

  3. Multifunctional Ceramic Nanostructured Coatings

    Science.gov (United States)

    2010-12-01

    Stansky D.V., Petrznik M.I., Levashov E.A., Mavrin B.N. // Surf. Coat. Tech. -2007.-V.201.- P . 6143-6147. 7. Kauffmann F., Dehm G., Schier V...5a. CONTRACT NUMBER STCU Registration No: P -253 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Anatolij Tarasovich Pugachov...lead to the increase in crystalline lattice rigidness, hardness, melting temperature and oxidation resistance in Me2B→MeB→ MeB2 line [13]. Boron p

  4. Microstructure, microhardness and dry friction behavior of cold-sprayed tin bronze coatings

    Science.gov (United States)

    Guo, Xueping; Zhang, Ga; Li, Wen-Ya; Dembinski, Lucas; Gao, Yang; Liao, Hanlin; Coddet, Christian

    2007-12-01

    In this paper, two types of tin bronze coatings (Cu-6 wt.% Sn and Cu-8 wt.% Sn) were prepared by cold spray process. The as-sprayed coatings were subjected to a vacuum heat treatment at 600 °C for 3 h. The coating microstructure, microhardness and tribological performance were characterized. The effects of the tin content and the vacuum heat treatment on the microstructure, microhardness and tribological behavior of the coatings were investigated. It is found that the as-sprayed CuSn6 (As6) and CuSn8 (As8) coatings exhibit practically an identical porosity. Meanwhile, As8 presents a higher microhardness than As6. In addition, the increase of the tin content in the powder feedstock leads to a lower wear rate. After a heat treatment, coating porosities are significantly reduced. However, the coating hardness is significantly decreased and the coating presents a much decreased wear resistance. For the as-sprayed coatings, such factors as ploughing and particle delamination could determine the sliding process. The heat treatment results in a distinct modification of the tribological behavior. For the annealed coatings, the adhesion, between the coating and the counterpart, could play a dominant role in the sliding process.

  5. The role of humans in facilitating and sustaining coat colour variation in domestic animals.

    Science.gov (United States)

    Linderholm, Anna; Larson, Greger

    2013-01-01

    Though the process of domestication results in a wide variety of novel phenotypic and behavioural traits, coat colour variation is one of the few characteristics that distinguishes all domestic animals from their wild progenitors. A number of recent reviews have discussed and synthesised the hundreds of genes known to underlie specific coat colour patterns in a wide range of domestic animals. This review expands upon those studies by asking how what is known about the causative mutations associated with variable coat colours, can be used to address three specific questions related to the appearance of non wild-type coat colours in domestic animals. Firstly, is it possible that coat colour variation resulted as a by-product of an initial selection for tameness during the early phases of domestication? Secondly, how soon after the process began did domestic animals display coat colour variation? Lastly, what evidence is there that intentional human selection, rather than drift, is primarily responsible for the wide range of modern coat colours? By considering the presence and absence of coat colour genes within the context of the different pathways animals travelled from wild to captive populations, we conclude that coat colour variability was probably not a pleiotropic effect of the selection for tameness, that coat colours most likely appeared very soon after the domestication process began, and that humans have been actively selecting for colour novelty and thus allowing for the proliferation of new mutations in coat colour genes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Statistical optimization of microencapsulation process for coating of magnesium particles with Viton polymer

    Energy Technology Data Exchange (ETDEWEB)

    Pourmortazavi, Seied Mahdi, E-mail: pourmortazavi@yahoo.com [Faculty of Material and Manufacturing Technologies, Malek Ashtar University of Technology, P.O. Box 16765-3454, Tehran (Iran, Islamic Republic of); Babaee, Saeed; Ashtiani, Fatemeh Shamsi [Faculty of Chemistry & Chemical Engineering, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of)

    2015-09-15

    Graphical abstract: - Highlights: • Surface of magnesium particles was modified with Viton via solvent/non-solvent method. • FT-IR, SEM, EDX, Map analysis, and TG/DSC techniques were employed to characterize the coated particles. • Coating process factors were optimized by Taguchi robust design. • The importance of coating conditions on resistance of coated magnesium against oxidation was studied. - Abstract: The surface of magnesium particles was modified by coating with Viton as an energetic polymer using solvent/non-solvent technique. Taguchi robust method was utilized as a statistical experiment design to evaluate the role of coating process parameters. The coated magnesium particles were characterized by various techniques, i.e., Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and thermogravimetry (TG), and differential scanning calorimetry (DSC). The results showed that the coating of magnesium powder with the Viton leads to a higher resistance of metal against oxidation in the presence of air atmosphere. Meanwhile, tuning of the coating process parameters (i.e., percent of Viton, flow rate of non-solvent addition, and type of solvent) influences on the resistance of the metal particles against thermal oxidation. Coating of magnesium particles yields Viton coated particles with higher thermal stability (632 °C); in comparison with the pure magnesium powder, which commences oxidation in the presence of air atmosphere at a lower temperature of 260 °C.

  7. Influence of coating defects on the corrosion behavior of cold sprayed refractory metals

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S., E-mail: skumar@arci.res.in; Rao, A. Arjuna

    2017-02-28

    Highlights: • Long duration immersion tests reveal inhomogeneous weight losses. • The weight loss for different coatings are well corroborated with the coating defects. • Chemical and micro structural analysis elucidates the reason behind the in homogeneous performance of different type of cold sprayed coatings. • In cold sprayed titanium, formation of oxide along the inter-splat boundary hinders the aggressive attack of the medium. - Abstract: The defects in the cold sprayed coatings are critical in the case of corrosion performances of the coatings in aggressive conditions. To understand the influence of coating defects on corrosion, immersion tests have been carried out in HF solution for the cold sprayed and heat treated Titanium, Tantalum and Niobium coatings. Long duration immersion tests reveal inhomogeneous weight losses of the samples prepared at different heat treatment conditions. The weight loss for different coatings has been well corroborated with the coating defects and microstructures. Chemical and micro structural analysis elucidates the reason behind the inhomogeneous performance of different type of cold sprayed coatings in corrosion medium. In the case of cold sprayed titanium, formation of stable oxide along the inter-splat boundary hinders the aggressive attack of the corrosion medium which is not so in other cases.

  8. Monitoring of tablet coating processes with colored coatings.

    Science.gov (United States)

    Barimani, Shirin; Kleinebudde, Peter

    2018-02-01

    Endpoints of coating processes for colored tablets were determined using in-line Raman spectroscopy. Coatings were performed with six commercially available formulations of pink, yellow, red, beige, green and blue color. The coatings were comprising pigments and/or dyes, some causing fluorescence and interfering the Raman signal. Using non-contact optics, a Raman probe was used as process analytical technology (PAT) tool, and acquired spectra were correlated to the sprayed mass of aqueous coating suspension. Process endpoints were determined using univariate (UV) data analysis and three multivariate analysis methods, namely Projection to Latent Structures (PLS)-regression, Science-Based Calibration (SBC) and Multivariate Curve Resolution (MCR). The methods were compared regarding model performance parameters. The endpoints of all coating experiments could be predicted until a total coating time of 50min corresponding to coating thicknesses between 21 and 38µm, depending on the density of the coat formulation. With the exception of SBC, all calibration methods resulted in R 2 values higher than 0.9. Additionally, the methods were evaluated regarding their capability for in-line process monitoring. For each color, at least two methods were feasible to do this. Overall, PLS-regression led to best model performance parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Copper-coated textiles: armor against MDR nosocomial pathogens.

    Science.gov (United States)

    Irene, Galani; Georgios, Priniotakis; Ioannis, Chronis; Anastasios, Tzerachoglou; Diamantis, Plachouras; Marianthi, Chatzikonstantinou; Philippe, Westbroek; Maria, Souli

    2016-06-01

    Soft surfaces in the health-care setting harbor potentially pathogenic bacteria and fungi that can be transferred to patients and personnel. We evaluated the in vitro antimicrobial efficacy of two types of innovative copper-coated textiles against a variety of nosocomial multi-drug resistant (MDR) pathogens. Five isolates each of MDR Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Enterococcus faecium as well as three Candida parapsilosis were tested. The antimicrobial activity of copper-coated para-aramide and copper-coated polyester swatches was compared to that of non-copper coated controls using a quantitative method. Reduction of viable colonies by >3log10 from starting inoculum was characterized as bactericidal activity. No viable colonies of S. aureus, P. aeruginosa, E. faecium and C. parapsilosis were recovered after the first hour of contact while for A. baumannii, no viable colonies were recovered after only 15min of contact with either type of copper-coated textiles. Copper-coated para-aramide exhibited a bactericidal effect at 15min of contact with A. baumannii, at 1h with S. aureus, P. aeruginosa, E. faecium and C. parapsilosis and at 3h with K. pneumoniae. Copper-coated polyester was bactericidal at 15min of contact for A. baumannii and at 1h for the other species tested. Both copper-coated textiles exhibited a rapid and significant antimicrobial effect. Antimicrobial textiles may have a role in the arsenal of strategies aiming to reduce environmental contamination in the health-care setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Superheating in coated niobium

    Science.gov (United States)

    Junginger, T.; Wasserman, W.; Laxdal, R. E.

    2017-12-01

    Using muon spin rotation it is shown that the field of first flux penetration {H}{entry} in Nb is enhanced by about 30% if coated with an overlayer of Nb3Sn or MgB2. This is consistent with an increase from the lower critical magnetic field {H}{{c}1} up to the superheating field {H}{sh} of the Nb substrate. In the experiments presented here coatings of Nb3Sn and MgB2 with a thickness between 50 and 2000 nm have been tested. {H}{entry} does not depend on material or thickness. This suggests that the energy barrier at the boundary between the two materials prevents flux entry up to {H}{sh} of the substrate. A mechanism consistent with these findings is that the proximity effect recovers the stability of the energy barrier for flux penetration, which is suppressed by defects for uncoated samples. Additionally, a low temperature baked Nb sample has been tested. Here a 6% increase of {H}{entry} was found, also pushing {H}{entry} beyond {H}{{c}1}.

  11. Federal Highway Administration 100-year coating study.

    Science.gov (United States)

    2012-11-01

    The Federal Highway Administration 100-Year Coating Study was initiated in August 2009 to search for durable : coating systems at a reasonable cost. The objective of the study was to identify and evaluate coating materials that can : provide 100 year...

  12. Intumescent coatings under fast heating

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere

    2012-01-01

    Intumescent coatings are widely used to delay or minimise the destructive effects of fire. They are usually tested under conditions that simulate the relatively slow build-up of heat in a normal fire. Here, the effects of damage during a fire causing sudden heating of the coating were studied....

  13. Westinghouse thermal barrier coatings development

    Energy Technology Data Exchange (ETDEWEB)

    Goedjen, J.G.; Wagner, G. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-01

    Westinghouse, in conjunction with the Department of Energy and Oak Ridge National Laboratory, has embarked upon a program for the development of advanced thermal barrier coatings for industrial gas turbines. Development of thermal barrier coatings (TBC`s) for industrial gas turbines has relied heavily on the transfer of technology from the aerospace industry. Significant differences in the time/temperature/stress duty cycles exist between these two coating applications. Coating systems which perform well in aerospace applications may not been optimized to meet power generation performance requirements. This program will focus on development of TBC`s to meet the specific needs of power generation applications. The program is directed at developing a state-of-the-art coating system with a minimum coating life of 25,000 hours at service temperatures required to meet increasing operating efficiency goals. Westinghouse has assembled a team of university and industry leaders to accomplish this goal. Westinghouse will coordinate the efforts of all program participants. Chromalloy Turbine Technologies, Inc. and Sermatech International, Inc. will be responsible for bond coat and TBC deposition technology. Praxair Specialty Powders, Inc. will be responsible for the fabrication of all bond coat and ceramic powders for the program. Southwest Research Institute will head the life prediction modelling effort; they will also be involved in coordinating nondestructive evaluation (NDE) efforts. Process modelling will be provided by the University of Arizona.

  14. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating

  15. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  16. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  17. Rapidly curable electrically conductive clear coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Mark P.; Anderson, Lawrence G.; Post, Gordon L.

    2018-01-16

    Rapidly curable electrically conductive clear coatings are applied to substrates. The electrically conductive clear coating includes to clear layer having a resinous binder with ultrafine non-stoichiometric tungsten oxide particles dispersed therein. The clear coating may be rapidly cured by subjecting the coating to infrared radiation that heats the tungsten oxide particles and surrounding resinous binder. Localized heating increases the temperature of the coating to thereby thermally cure the coating, while avoiding unwanted heating of the underlying substrate.

  18. Functional Plasma-Deposited Coatings

    Directory of Open Access Journals (Sweden)

    Mykhaylo Pashechko

    2017-12-01

    Full Text Available The paper focuses on the problem of low adhesion of plasma sprayed coatings to the substrate. The subsequent laser treatment modes and their influence on the coating-substrate interface were studied. This allows to decrease the level of metstability of the coating, thus decreasing its hardness down to 11-12 GPa on the surface and to about 9 GPa on depth of 400 µm. The redistribution of alloying elements through solid and liquid diffusion improves mechanical properties and rises the adhesion up to 450 MPa after remelting and up to 90-110 MPa after laser-aided thermal cycling. At he same time, remelting of coating helps to decrease its porosity down to 1%. Obtained complex of properties also allows to improve wear resistance of coatings and to decrease friction factor.

  19. Foundry Coating Technology: A Review

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2011-01-01

    The importance of foundry coating in improving the surface quality of castings cannot be over emphasized. The appli-cation of mould and core washes creates a high thermal integrity barrier between the metal and the mould resulting in the reduction of the thermal shock experienced by the sand system....... These thermal shock leads to series of surface de-fects such as veining/finning, metal penetration, burn-on/in, scab, rat tail, erosion etc. The use of coatings reduces the tendency of occurrence of these defects. However, the understanding of the coating, its components, characteristics and mechanism of action...... is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach....

  20. Multilayer Microlaminated Ceramic Thermal Barrier Coating

    National Research Council Canada - National Science Library

    Yu, Charles

    1997-01-01

    .... Both thermal and mechanical characteristics of the coatings can be potentially optimized, and the coating will be more tolerant towards strain damage, have better thermal insulation and provide...

  1. The Numerical Modeling of Thermal Stress Distribution in Thermal Barrier Coatings

    Directory of Open Access Journals (Sweden)

    Jasik A.

    2017-09-01

    Full Text Available The paper presents the results of numerical calculations of temperature and thermal stress distribution in thermal barrier coatings deposited by thermal spraying process on the nickel based superalloy. An assumption was made to apply conventional zirconium oxide modified with yttrium oxide (8YSZ and apply pyrochlore type material with formula La2Zr2O7. The bond coat was made of NiCoCrAlY. Analysis of the distribution of temperature and stresses in ceramic coatings of different thicknesses was performed in the function of bond-coat thickness and the type of ceramic insulation layer. It was revealed that the thickness of NiCrAlY bond-coat has not significant influence on the stress distribution, but there is relatively strong effect on temperature level. The most important factor influenced on stress distribution in TBC system is related with type and properties of ceramic insulation layer.

  2. Free Electron Laser Synthesis of Functional Coatings

    Science.gov (United States)

    Schaaf, Peter; Höche, Daniel

    Functional and smart surfaces and coatings play an increasingly decisive role in the applicability and performance of modern materials. From an industrial point of view, there is a great interest with respect to friction, wear, corrosion, and further properties. Many methods have been developed for the improvement of the respective surface and material properties. Traditionally, these treatments range from simple PVD and CVD processes to complicated plasma and hybrid methods. Recently, it has been established that short laser pulses of high energy can induce a direct laser synthesis of functional coatings if the material's surface is irradiated in a reactive atmosphere. The process is based on a complicated combination of laser plasma - gas - material surface interactions. Tests for steel, aluminum, magnesium, titanium, and silicon in nitrogen, methane, and hydrogen atmospheres have been carried out successfully; with these materials, interesting coatings can be produced by direct laser synthesis, for example, AlN and SiC. Various laser types can be used for this purpose: Excimer, Nd:YAG, CO2 Laser, and even the free electron laser (FEL).

  3. Coatings to prevent frost

    DEFF Research Database (Denmark)

    Lusada, Ricardo; Holberg, Stefan; Bennedsen, Jeanette Marianne Dalgaard

    2016-01-01

    at temperatures just below 0°C, for example at −4°C, is low. Freezing of a single drop on aluminum leads, however, to instant freezing of the complete surface. On hydrophobic coatings, such a freezing drop is isolated; the frozen area grows slowly. At −4°C surface temperature in a +12°C/90% relative humidity...... environment, on surfaces providing a water contact angle hysteresis of about 10° and receding water contact angles higher than 90°, a rate for the growth of the average radius of the frozen area of about 2 µm/s was observed. Submitting the surface to an airflow of 1 m/s led to faster frost spreading in flow...

  4. Microstructure of laser-clad SiC-(Ni alloy) composite coating

    NARCIS (Netherlands)

    Pei, Y.T.; Ouyang, J.H.; Lei, T.C.; Zhou, Y.

    1995-01-01

    The laser cladding technique was used to produce Ni alloy coatings with different SiC particle (SiCp) contents on steel 1045. The complete dissolution of SiCp took place during laser melting and led to a microstructural evolution of the coatings associated with the SiCp content. M7X3 or M23X6-type

  5. ELECTRICAL FURNACE FOR PRODUCING CARBIDE COATINGS USING THE THERMOREACTIVE DEPOSITION/DIFFUSION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    FABIO CASTILLEJO

    2011-01-01

    the presence of VC and NbC, and as MEB results clearly show, the formation of regular thickness coatings. The results obtained allow for assessing that the designed and built furnace fulfills the requirements of the TRD technique for obtaining different types of hard coatings.

  6. Nature Inspired Surface Coatings

    Science.gov (United States)

    Rubner, Michael

    2011-04-01

    Materials Scientists more and more are looking to nature for clues on how to create highly functional surface coatings with exceptional properties. The fog harvesting capabilities of the Namib Desert beetle, the beautiful iridescent colors of the hummingbird, and the super water repellant abilities of the Lotus leaf are but a few examples of the amazing properties developed over many years in the natural world. Nature also makes extensive use of the pH-dependent behavior of weak functional groups such as carboxylic acid and amine functional groups. This presentation will explore synthetic mimics to the nano- and microstructures responsible for these fascinating properties. For example, we have demonstrated a pH-induced porosity transition that can be used to create porous films with pore sizes that are tunable from the nanometer scale to the multiple micron scale. The pores of these films, either nano- or micropores, can be reversibly opened and closed by changes in solution pH. The ability to engineer pH-gated porosity transitions in heterostructured thin films has led to the demonstration of broadband anti-reflection coatings that mimic the anti-reflection properties of the moth eye and pH-tunable Bragg reflectors with a structure and function similar to that found in hummingbird wings and the Longhorn beetle. In addition, the highly textured honeycomb-like surfaces created by the formation of micron-scale pores are ideally suited for the creation of superhydrophobic surfaces that mimic the behavior of the self-cleaning lotus leaf. The development of synthetic "backbacks" on immune system cells that may one day ferry drugs to disease sites will also be discussed.

  7. High performance polypyrrole coating for corrosion protection and biocidal applications

    Science.gov (United States)

    Nautiyal, Amit; Qiao, Mingyu; Cook, Jonathan Edwin; Zhang, Xinyu; Huang, Tung-Shi

    2018-01-01

    Polypyrrole (PPy) coating was electrochemically synthesized on carbon steel using sulfonic acids as dopants: p-toluene sulfonic acid (p-TSA), sulfuric acid (SA), (±) camphor sulfonic acid (CSA), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS). The effect of acidic dopants (p-TSA, SA, CSA) on passivation of carbon steel was investigated by linear potentiodynamic and compared with morphology and corrosion protection performance of the coating produced. The types of the dopants used were significantly affecting the protection efficiency of the coating against chloride ion attack on the metal surface. The corrosion performance depends on size and alignment of dopant in the polymer backbone. Both p-TSA and SDBS have extra benzene ring that stack together to form a lamellar sheet like barrier to chloride ions thus making them appropriate dopants for PPy coating in suppressing the corrosion at significant level. Further, adhesion performance was enhanced by adding long chain carboxylic acid (decanoic acid) directly in the monomer solution. In addition, PPy coating doped with SDBS displayed excellent biocidal abilities against Staphylococcus aureus. The polypyrrole coatings on carbon steels with dual function of anti-corrosion and excellent biocidal properties shows great potential application in the industry for anti-corrosion/antimicrobial purposes.

  8. Tribology of nitrided-coated steel-a review

    Science.gov (United States)

    Bhaskar, Santosh V.; Kudal, Hari N.

    2017-01-01

    Surface engineering such as surface treatment, coating, and surface modification are employed to increase surface hardness, minimize adhesion, and hence, to reduce friction and improve resistance to wear. To have optimal tribological performance of Physical Vapor Deposition (PVD) hard coating to the substrate materials, pretreatment of the substrate materials is always advisable to avoid plastic deformation of the substrate, which may result in eventual coating failure. The surface treatment results in hardening of the substrate and increase in load support effect. Many approaches aim to improve the adhesion of the coatings onto the substrate and nitriding is the one of the best suitable options for the same. In addition to tribological properties, nitriding leads to improved corrosion resistance. Often corrosion resistance is better than that obtainable with other surface engineering processes such as hard-chrome and nickel plating. Ability of this layer to withstand thermal stresses gives stability which extends the surface life of tools and other components exposed to heat. Most importantly, the nitrogen picked-up by the diffusion layer increases the rotating-bending fatigue strength in components. The present article reviews mainly the tribological advancement of different nitrided-coated steels based on the types of coatings, structure, and the tribo-testing parameters, in recent years.

  9. POLYETHERSULFONE COATING FOR MITIGATING CORROSION OF STEEL IN GEOTHERMAL ENVIRONMENT.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.

    2005-06-01

    Emphasis was directed toward evaluating the usefulness of a polyethersulfone (PES)-dissolved N-methyl pyrrolidone (NMP) solvent precursor as a low-temperature film-forming anti-corrosion coating for carbon steel in simulated geothermal environments at brine temperatures up to 300 C. A {approx} 75 {micro}m thick PES coating performed well in protecting the steel against corrosion in brine at 200 C. However, at {>=} 250 C, the PES underwent severe hydrothermal oxidation that caused the cleavage of sulfone- and ether-linkages, and the opening of phenyl rings. These, in turn, led to sulfone {yields} benzosulfonic acid and ether {yields} benzophenol-type oxidation derivative transformations, and the formation of carbonyl-attached open rings, thereby resulting in the incorporation of the functional groups, hydroxyl and carbonyl, into the coating. The presence of these functional groups raised concerns about the diminutions in water-shedding and water-repellent properties that are important properties of the anti-corrosion coatings; such changes were reflected in an enhancement of the magnitude of susceptibility of the coatings surfaces to moisture. Consequently, the disintegration of the PES structure by hydrothermal oxidation was detrimental to the maximum efficacy of the coating in protecting the steel against corrosion, allowing the corrosive electrolytes to infiltrate easily through it.

  10. Gas-driven hydrogen permeation through tungsten-coated graphite

    Energy Technology Data Exchange (ETDEWEB)

    Golubeva, A.V., E-mail: anna-golubeva@yandex.ru [RRC ' Kurchatov Institute' , Ac. Kurchatov sq., 1/1, Moscow RU-123182 (Russian Federation); Spitsyn, A.V., E-mail: spitsyn@nfi.kiae.ru [RRC ' Kurchatov Institute' , Ac. Kurchatov sq., 1/1, Moscow RU-123182 (Russian Federation); Mayer, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Cherkez, D.I. [RRC ' Kurchatov Institute' , Ac. Kurchatov sq., 1/1, Moscow RU-123182 (Russian Federation); Schwarz-Selinger, T.; Koch, F.; Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Skovoroda, A.A. [RRC ' Kurchatov Institute' , Ac. Kurchatov sq., 1/1, Moscow RU-123182 (Russian Federation)

    2011-08-01

    Hydrogen gas-driven permeation through graphite coated with different types of tungsten coatings with thicknesses up to 200 {mu}m has been investigated. The substrate material was fine-grain graphite R5710 and R6710, which properties with respect to hydrogen transport are well known . Magnetron-sputtered W coatings of thicknesses 1 and 3 {mu}m and two coatings of ASDEX Upgrade were investigated: A 3 {mu}m thick layer of tungsten deposited by physical vapor deposition (PVD-W) and 200 {mu}m thick layers of tungsten deposited by plasma-spaying in vacuum (VPS-W). The gas-driven permeation was investigated at a pressure gradient of 10{sup -2}-150 Pa. The gas-driven permeation occurs through the carbon base-materials by hydrogen molecular gas flow through the internal porosity network rather than hydrogen atom diffusion through the graphite lattice. It was found that W coatings with thicknesses up to 3 {mu}m are transparent for hydrogen gas penetration and do not influence the permeability of coated fine-grain graphite, because the open porosity system of graphite remains open. Even a 200 {mu}m thick layer of VPS-W has an open system of connected pores, which connects the front and rear surfaces of the deposited layer.

  11. Graphene Nanoplatelets Based Protective and Functionalizing Coating for Stainless Steel.

    Science.gov (United States)

    Mondal, Jayanta; Kozlova, Jekaterina; Sammelselg, Väino

    2015-09-01

    Stainless steel is the most widely used alloy for many industrial and everyday applications, and protection of this alloy substrate against corrosion is an important industrial issue. Here we report a promising application of graphene oxide and graphene nanoplatelets as effective corrosion inhibitors for AISI type 304 stainless steel alloy. The graphene oxide and graphene coatings on the stainless steel substrates were prepared using spin coating techniques. Homogeneous and complete surface coverage by the graphene oxide and graphene nanoplatelets were observed with a high-resolution scanning electron microscope. The corrosion inhibition ability of these materials was investigated through measurement of open circuit potential and followed by potentiodymamic polarization analysis in aqueous sodium chloride solution before and after a month of immersion. Analyzed result exhibits effective corrosion inhibition for both substrates coated with graphene oxide or graphene nanoplatelets by increasing corrosion potential, pitting potential and decreasing passive current density. The corrosion inhibition ability of the coated substrates has not changed even after the long-term immersion. The result showed both graphene materials can be used as an effective corrosion inhibitor for the stainless steel substrates, which would certainly increase lifetime the substrate. However, long-term protection ability of the graphene coated susbtsrate showed somewhat better inhibition performance than the ones coated with graphene oxide.

  12. Nanoparticle-coated organic-inorganic microparticles: experimental design and gastrointestinal tolerance evaluation

    Directory of Open Access Journals (Sweden)

    Ruy Carlos R. Beck

    2006-10-01

    Full Text Available The influences of the spray-drying parameters and the type of nanoparticles (nanocapsules or nanospheres on the characteristics of nanoparticle-coated diclofenac-loaded microparticles were investigated by using a factorial design 3². Gastrointestinal tolerance following oral administration in rats was evaluated. Formulations were selected considering the best yields, the best encapsulation efficiencies and the lowest water contents, presenting surfaces completely coated by nanostructures and a decrease in the surface areas in relation to the uncoated core. In vitro drug release demonstrated the influence of the nanoparticle-coating on the dissolution profiles of diclofenac. Nanocapsule-coated microparticles presented a protective effect on the gastrointestinal mucosa.

  13. Nanoparticle-coated organic-inorganic microparticles: experimental design and gastrointestinal tolerance evaluation

    Directory of Open Access Journals (Sweden)

    Beck Ruy Carlos R.

    2006-01-01

    Full Text Available The influences of the spray-drying parameters and the type of nanoparticles (nanocapsules or nanospheres on the characteristics of nanoparticle-coated diclofenac-loaded microparticles were investigated by using a factorial design 3². Gastrointestinal tolerance following oral administration in rats was evaluated. Formulations were selected considering the best yields, the best encapsulation efficiencies and the lowest water contents, presenting surfaces completely coated by nanostructures and a decrease in the surface areas in relation to the uncoated core. In vitro drug release demonstrated the influence of the nanoparticle-coating on the dissolution profiles of diclofenac. Nanocapsule-coated microparticles presented a protective effect on the gastrointestinal mucosa.

  14. Multispectral Image Analysis for Robust Prediction of Astaxanthin Coating

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Frosch, Stina; Nielsen, Michael Engelbrecht

    2013-01-01

    The aim of this study was to investigate the possibility of predicting the type and concentration level of astaxanthin coating of aquaculture feed pellets using multispectral image analysis. We used both natural and synthetic astaxanthin, and we used several different concentration levels...... regression (PLSR) for prediction of the concentration level. The results show that it is possible to predict the level of synthetic astaxanthin coating using PLSR on either the same recipe, or when calibrating on all recipes. The concentration prediction is adequate for screening for all recipes. Moreover......, it shows that it is possible to predict the type of astaxanthin used in the coating using only ten spectral bands. Finally, the most selected spectral bands for astaxanthin prediction are in the visible range of the spectrum....

  15. Sorption of Arsenite onto Mackinawite Coated Sand

    Science.gov (United States)

    Gallegos, T. J.; Hayes, K. F.; Abriola, L. M.

    2004-05-01

    Arsenic contamination of groundwater is a widespread problem affecting aquifers in the United States as well as abroad. Recent strengthening of the US EPA MCL for arsenic has prompted the need for technology capable of removing both arsenite and arsenate from solution. Arsenite, the more toxic form of arsenic, is more difficult to remove from anoxic zones in the subsurface. Studies by others have demonstrated the affinity of some types of iron sulfides for arsenite, such as troilite, pyrite, amorphous iron sulfide and mackinawite. However, these studies have not provided a comprehensive investigation of the macroscopic behavior of arsenite in the presence of crystalline mackinawite in a form that can be readily applied to real-world treatment technologies. This study examines the behavior of arsenite in the presence of mackinawite coated sand. PH edge results demonstrate that arsenite sorption onto mackinawite coated sand increases with increasing pH, reaching maximum removal at pH 10. Arsenite removal, albeit slight, occurring below pH 5 is independent of pH indicative of a different removal mechanism. Isotherm studies show that at low concentrations, removal is Langmuirian in nature. Arsenite sorption abruptly converts to linear behavior at high concentrations, possibly attributed to the saturation of the monolayer. Ionic strength effects were assessed by comparing pH edge data developed for three different concentrations of NaCl background electrolyte solution. Increases in ionic strength enhance the removal of arsenite from solution, suggesting possible inner-sphere surface complexation removal mechanisms. Information gathered in this study can be used to further develop surface complexation models to describe and predict reactivity of arsenite in the presence of mackinawite coated sands in anoxic regions. Mackinawite coated sands investigated here may provide a feasible reactive medium for implementation in above-ground sorption reactors or subsurface

  16. Manufacturing of freeform mirror by milling and altering its optical characteristics by Ns-laser polishing and ALD coatings

    Science.gov (United States)

    Mutanen, Jarkko; Kaakkunen, Jarno J. J.; Tuovinen, Hemmo; Hiltunen, Jouni; Kivi, Sini; Toiviainen, Maunu; Väyrynen, Juha; Laukkanen, Janne; Prokofiev, Victor; Pääkkönen, Pertti; Juuti, Mikko; Kuittinen, Markku; Mönkkönen, Kari

    2014-09-01

    In this study we tested ns-laser and an atomic layer deposition (ALD) for polishing and coating CNC-machined aluminum freeform mirrors that are used in a compact multipoint fiber optical probe. Two types of ALD coatings, aluminum oxide and silicon dioxide were tested. The surface roughness of mirrors was analyzed prior to and after nanosecond-laser polishing and coating them on a Beneq TFS 200 ALD device. The freeform aluminum mirrors with and without coatings were then measured with optical profiler. The results show that improvement in the surface roughness can be seen with ns-laser polished and ALD coated aluminum surfaces.

  17. Environmentally Friendly Coating Technology for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.; Jolley, Scott T.; Pearman, Benjamin P.; Zhang, Xuejun; Fitzpatrick, Lilliana; Gillis, Mathew; Blanton, Michael; hide

    2016-01-01

    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry.

  18. Avian Egg and Egg Coat.

    Science.gov (United States)

    Okumura, Hiroki

    2017-01-01

    An ovulated egg of vertebrates is surrounded by unique extracellular matrix, the egg coat or zona pellucida, playing important roles in fertilization and early development. The vertebrate egg coat is composed of two to six zona pellucida (ZP) glycoproteins that are characterized by the evolutionarily conserved ZP-domain module and classified into six subfamilies based on phylogenetic analyses. Interestingly, investigations of biochemical and functional features of the ZP glycoproteins show that the roles of each ZP-glycoprotein family member in the egg-coat formation and the egg-sperm interactions seemingly vary across vertebrates. This might be one reason why comprehensive understandings of the molecular basis of either architecture or physiological functions of egg coat still remain elusive despite more than 3 decades of intensive investigations. In this chapter, an overview of avian egg focusing on the oogenesis are provided in the first section, and unique features of avian egg coat, i.e., perivitelline layer, including the morphology, biogenesis pathway, and physiological functions are discussed mainly on chicken and quail in terms of the characteristics of ZP glycoproteins in the following sections. In addition, these features of avian egg coat are compared to mammalian zona pellucida, from the viewpoint that the structural and functional varieties of ZP glycoproteins might be associated with the evolutionary adaptation to their reproductive strategies. By comparing the egg coat of birds and mammals whose reproductive strategies are largely different, new insights into the molecular mechanisms of vertebrate egg-sperm interactions might be provided.

  19. Novel hydroxyapatite-forsterite-bioglass nanocomposite coatings with improved mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sebdani, M. Mazrooei, E-mail: m.mazrooei@ma.iut.ac.ir [Biomaterials Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Fathi, M.H. [Biomaterials Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2011-02-03

    The purpose of this work was fabrication and evaluation of mechanical properties of hydroxyapatite-forsterite-bioactive glass nanocomposite coatings. The novel hydroxyapatite-forsterite-bioactive glass nanocomposite coating on 316L stainless steel (SS) was prepared via a sol-gel process. The X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray analysis (EDX) techniques were used to investigate the microstructure and morphology of the coatings. The local mechanical properties, e.g. nano-hardness, elastic modulus and fracture toughness of four type coatings with different amounts of forsterite, were determined by nano-indentation method using load and displacement data. The nano-indentation tester was equipped with Atomic Force Microscopy to image the indenter mark. The crack-free and homogeneous nanocomposite coatings with no observable defects were prepared. The coatings showed the hardness and elastic modulus values in the range of 2.4-3.4 (GPa) and 46-96 (GPa), respectively. The fracture toughness values of nanocomposite coatings also varied in the range of 0.56-0.972 (MPa m{sup 0.5}). The results showed that the elastic modulus, hardness and fracture toughness values of prepared composite coatings increased with increase in forsterite amounts. Results suggested that novel composite coatings might be potentially useful for biomedical applications especially as an implant coating for hard tissue treatment.

  20. 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

    2017-01-01

    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.

  1. Effect of Nb Doping on High Temperature Oxidation Resistance of Ti-Al Alloyed Coatings

    Directory of Open Access Journals (Sweden)

    DAI Jing-jie

    2017-02-01

    Full Text Available Ti-Al alloyed coatings with different Nb doping contents were fabricated on TC4 titanium alloy by laser surface alloying to improve high temperature oxidation resistance of the alloy. Structures and high temperature oxidation behaviors of the alloyed coatings were analyzed and tested by X-ray diffraction (XRD, scanning electron microscope (SEM, energy dispersive spectrometer (EDS and box-type resistance furnace. The results show that the alloyed coatings consist of TiAl and Ti3Al, and no niobium compound are formed in Ti-Al-Nb alloyed coatings. The alloyed coatings are uniform and exhibit excellent metallurgical bonding with the substrates. A large amount of surface cracks and a few penetrating cracks are formed in Ti-Al alloyed coating without Nb doping, while no obvious cracks are formed in Ti-Al alloyed coating with Nb doping. The oxidation mass gains of all the alloyed coatings were significantly lower than those of the substrate. The alloyed coatings with Nb doping exhibit more excellent high temperature oxidation resistance due to the beneficial machanism of Nb doping. The mechanism of Nb doping on improving high temperature oxidation resistance of Ti-Al alloyed coatings includes reducing the defect concentration of TiO2, refining oxide grains and promoting the formation of Al2O3.

  2. Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method.

    Science.gov (United States)

    Seo, Dong Seok; Lee, Jong Kook; Hwang, Kyu Hong; Hahn, Byung Dong; Yoon, Seog Young

    2015-08-01

    Three types of raw materials were used for the fabrication of hydroxyapatite coatings by using the room temperature spraying method and their influence on the microstructure and in vitro characteristics were investigated. Starting hydroxyapatite powders for coatings on titanium substrate were prepared by a heat treatment at 1100 °C for 2 h of bovine bone, bone ash, and commercial hydroxyapatite powders. The phase compositions and Ca/P ratios of the three hydroxyapatite coatings were similar to those of the raw materials without decomposition or formation of a new phase. All hydroxyapatite coatings showed a honeycomb structure, but their surface microstructures revealed different features in regards to surface morphology and roughness, based on the staring materials. All coatings consisted of nano-sized grains and had dense microstructure. Inferred from in vitro experiments in pure water, all coatings have a good dissolution-resistance and biostability in water.

  3. Poly(meth)acrylate-based coatings.

    Science.gov (United States)

    Nollenberger, Kathrin; Albers, Jessica

    2013-12-05

    Poly(meth)acrylate coatings for pharmaceutical applications were introduced in 1955 with the launch of EUDRAGIT(®) L and EUDRAGIT(®) S, two types of anionic polymers. Since then, by introducing various monomers into their polymer chains and thus altering their properties, diverse forms with specific characteristics have become available. Today, poly(meth)acrylates function in different parts of the gastrointestinal tract and/or release the drug in a time-controlled manner. This article reviews the properties of various poly(meth)acrylates and discusses formulation issues as well as application possibilities. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Integrated Glass Coating Manufacturing Line

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor [Enki Technology Inc., San Jose, CA (United States)

    2015-09-30

    This project aims to enable US module manufacturers to coat glass with Enki’s state of the art tunable functionalized AR coatings at the lowest possible cost and highest possible performance by encapsulating Enki’s coating process in an integrated tool that facilitates effective process improvement through metrology and data analysis for greater quality and performance while reducing footprint, operating and capital costs. The Phase 1 objective was a fully designed manufacturing line, including fully specified equipment ready for issue of purchase requisitions; a detailed economic justification based on market prices at the end of Phase 1 and projected manufacturing costs and a detailed deployment plan for the equipment.

  5. Laser-based coatings removal

    Energy Technology Data Exchange (ETDEWEB)

    Freiwald, J.G.; Freiwald, D.A. [F2 Associates, Inc., Albuquerque, NM (United States)

    1995-10-01

    Over the years as building and equipment surfaces became contaminated with low levels of uranium or plutonium dust, coats of paint were applied to stabilize the contaminants in place. Most of the earlier paint used was lead-based paint. More recently, various non-lead-based paints, such as two-part epoxy, are used. For D&D (decontamination and decommissioning), it is desirable to remove the paints or other coatings rather than having to tear down and dispose of the entire building. This report describes the use of pulse-repetetion laser systems for the removal of paints and coatings.

  6. Nano-coatings on carbon structures for interfacial modification

    Science.gov (United States)

    Pulikollu, Rajasekhar V.

    Surface modification of materials is a rapidly growing field as structures become smaller, more integrated and complex. It opens up the possibility of combining the optimum bulk properties of a material with optimized surface properties such as enhanced bonding, corrosion resistance, reactivity, stress transfer, and thermal, optical or electrical behavior. Therefore, surface functionalization or modification can be an enabling step in a wide variety of modern applications. In this dissertation several surface modification approaches on carbon foam and carbon nano-fibers will be discussed. These are recently developed sp2 graphitic carbon based structures that have significant potential in aerospace, automotive and thermal applications. Influence of surface modification on composite formation and properties have also been investigated. Two types of property changes have been investigated: one for enhancing the surface reactivity and another for surface inertness. Characterization techniques such as X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), Contact Angle Measurement, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and mechanical testing are used in this study to find out the influence of these coatings on surface composition, chemistry and morphology. Mechanical testing has been performed on composites and stand alone foam to study the influence of surface modification on physical and mechanical properties of the composite materials. The effectiveness of these coatings on metallic/graphite interface has also been investigated for metal-matrix composite related applications. Additionally, the influence of plasma coatings on nucleation and growth of nanotubes on larger carbon structures (to produce multiscale, multifunctional materials) have also been studied. It is seen that the liquid phase activation treatment introduces oxygen functional groups on the surface, but may cause severe enough degradation that

  7. Effects of calcium phosphate composition in sputter coatings on in vitro and in vivo performance.

    Science.gov (United States)

    Urquia Edreira, Eva R; Wolke, Joop G C; Aldosari, Abdullah AlFarraj; Al-Johany, Sulieman S; Anil, Sukumaran; Jansen, John A; van den Beucken, Jeroen J J P

    2015-01-01

    Calcium phosphate (CaP) ceramic coatings have been used to enhance the biocompatibility and osteoconductive properties of metallic implants. The chemical composition of these ceramic coatings is an important parameter, which can influence the final bone performance of the implant. In this study, the effect of phase composition of CaP-sputtered coatings was investigated on in vitro dissolution behavior and in vivo bone response. Coatings were prepared by a radio frequency (RF) magnetron sputtering technique; three types of CaP target materials were used to obtain coatings with different stoichiometry and calcium to phosphate ratios (hydroxyapatite (HA), α-tricalciumphosphate (α-TCP), and tetracalciumphosphate (TTCP)) were compared with non-coated titanium controls. The applied ceramic coatings were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma optical emission spectroscopy. The in vitro dissolution/precipitation of the CaP coatings was evaluated using immersion tests in simulated body fluid (SBF). To mimic the in vivo situation, identical CaP coatings were also evaluated in a femoral condyle rabbit model. TCPH and TTCPH showed morphological changes during 4-week immersion in SBF. The results of bone implant contact (BIC) and peri-implant bone volume (BV) showed a similar response for all experimental coatings. An apparent increase in tartrate resistant acid phosphatase (TRAP) positive staining was observed in the peri-implant region with decreasing coating stability. In conclusion, the experimental groups showed different coating properties when tested in vitro and an apparent increase in bone remodeling with increasing coating dissolution in vivo. © 2014 Wiley Periodicals, Inc.

  8. Hex Chrome Free Coatings for Electronics Overview

    Science.gov (United States)

    Kessel, Kurt

    2013-01-01

    The overall objective of the Hex Chrome Free Coatings for Electronics project is to evaluate and test pretreatment coating systems not containing hexavalent chrome in avionics and electronics housing applications. This objective will be accomplished by testing strong performing coating systems from prior NASA and DoD testing or new coating systems as determined by the stakeholders.

  9. 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.

  10. Precursor-Less Coating of Nanoparticles in the Gas Phase

    NARCIS (Netherlands)

    Pfeiffer, T.V.; Kedia, P.; Messing, M.E.; Valvo, M.; Schmidt-Ott, A.

    2015-01-01

    This article introduces a continuous, gas-phase method for depositing thin metallic coatings onto (nano)particles using a type of physical vapor deposition (PVD) at ambient pressure and temperature. An aerosol of core particles is mixed with a metal vapor cloud formed by spark ablation by passing

  11. Evaluation of Glider Coatings against Biofouling for Improved Flight Performance

    Science.gov (United States)

    2010-09-30

    We received 10 different samples from UCSD/Scripps, operating the spray glider . There was one sample from Webb Research Inc., operating the slocum ...three glider types (Spray, Slocum , and Seaglider) in the biofoulingassessment field site in Morro Bay, CA. Samples will be maintained and...DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Evaluation of Glider Coatings against Biofouling for Improved

  12. Particle coating – a novel trend in energetic materials engineering

    NARCIS (Netherlands)

    Abadjieva, E.; Heijden, A.E.D.M. van der; Creyghton, Y.L.M.

    2010-01-01

    The development of new energetic materials with enhanced blast properties requires better understanding of factors as particle type, size and particle/matrix distribution. The ability of growing a coating on particles opens new possibilities in energetic materials engineering. Functionalities as

  13. Prognostic importance of white coat and masked hypertention

    DEFF Research Database (Denmark)

    Gustavsen, Pia; Hansen, Tine

    2009-01-01

    The growing use of ambulatory blood pressure monitoring has led to an increased awareness of the two types of discrepancy between office blood pressure and ambulatory blood pressure, called white coat hypertension (WCH) and masked hypertension (MH). Based on several longitudinal studies, WCH...

  14. Prognostisk betydning af "white coat" og maskeret hypertension

    DEFF Research Database (Denmark)

    Gustavsen, Pia; Hansen, Tine Willum

    2009-01-01

    The growing use of ambulatory blood pressure monitoring has led to an increased awareness of the two types of discrepancy between office blood pressure and ambulatory blood pressure, called white coat hypertension (WCH) and masked hypertension (MH). Based on several longitudinal studies, WCH...

  15. Titania coated hollow glass microspheres for environmental applications

    Science.gov (United States)

    Koopman, Mark C.

    The potential applicability of titania coated hollow glass microspheres (HGMs) to the photocatalytic degradation of microbiological and organic chemical water pollutants could have dramatic positive effects on improving the quality of industrial wastewaters that empty into rivers and streams, as well as potential use in economically improving the quality of drinking water. Heterogeneous photocatalysis using titania has been extensively studied since the 1990's because of its non-toxic nature, its high quantum yield of electrons and photo-holes, and its ability to use ambient solar radiation as a power source. Although titania embodies extraordinarily attractive properties for a range of environmental applications, a viable substrate or method of using the material effectively has not been recognized. HGMs are particularly attractive as a support for titania because of their low density and high surface area to volume ratio, but details of how they react to imposed loading, wear, and impact have not been addressed, nor have materials engineering analyses that could maximize their utility been made. In this study we have examined the microstructure, morphology and micro-compression properties of two types of titania coated hollow microspheres, a commercially produced HGM and cenospheres, a derivative of fly ash. Comparisons of uncoated and titania coated hollow microspheres showed improved failure loads and facture energies for the titania coated materials over the uncoated hollow microspheres. Also, the relationship between failure load and hollow microsphere diameter was characterized and the function employed to explain part of the gain in average failure load for the HGMs. Microscopic examination of titania coated HGMs that were subjected to various turbulent conditions, as well as intentional fracture, indicated good interfacial integrity, which supports the viability of both types of HGMs for potential applications. The photocatalytic reactivity of the titania

  16. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  17. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  18. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  19. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  20. Positron studies of polymeric coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jean, Y.C. E-mail: jeany@umkc.edu; Mallon, P.E.; Zhang, R.; Chen Hongmin; Li Ying; Zhang Junjie; Wu, Y.C.; Sandreczki, T.C.; Suzuki, R.; Ohdaira, T.; Gu, X.; Nguyen, T

    2003-11-01

    In complicated coating systems, positrons have shown sensitivity in detecting the early stage of deterioration due to weathering, specially, in probing a specific location or depth of coatings from the surface through interfaces and the bulk. Existing extensive experimental positron data show that positron annihilation signals respond quantitatively to the deterioration process due to weathering. Now it is possible to detect the very early stage of coating deterioration at the atomic and molecular scale by using positrons, typically in days as compared to years by conventional methods. This paper summarizes recent positron studies in polymeric coatings. Correlations between positron data and a variety of chemical, physical and engineering data from ESR, AFM, cross-link density, gloss, and cyclic loading are presented.

  1. Method of measuring metal coating adhesion

    Science.gov (United States)

    Roper, J.R.

    A method for measuring metal coating adhesion to a substrate material comprising the steps of preparing a test coupon of substrate material having the metal coating applied to one surface thereof, applying a second metal coating of gold or silver to opposite surfaces of the test coupon by hot hollow cathode process, applying a coating to one end of each of two pulling rod members, joining the coated ends of the pulling rod members to said opposite coated surfaces of the test coupon by a solid state bonding technique and finally applying instrumented static tensile loading to the pulling rod members until fracture of the metal coating adhesion to the substrate material occurs.

  2. Transcriptome Analysis of a New Peanut Seed Coat Mutant for the Physiological Regulatory Mechanism Involved in Seed Coat Cracking and Pigmentation.

    Science.gov (United States)

    Wan, Liyun; Li, Bei; Pandey, Manish K; Wu, Yanshan; Lei, Yong; Yan, Liying; Dai, Xiaofeng; Jiang, Huifang; Zhang, Juncheng; Wei, Guo; Varshney, Rajeev K; Liao, Boshou

    2016-01-01

    Seed-coat cracking and undesirable color of seed coat highly affects external appearance and commercial value of peanuts ( Arachis hypogaea L.). With an objective to find genetic solution to the above problems, a peanut mutant with cracking and brown colored seed coat (testa) was identified from an EMS treated mutant population and designated as "peanut seed coat crack and brown color mutant line ( pscb )." The seed coat weight of the mutant was almost twice of the wild type, and the germination time was significantly shorter than wild type. Further, the mutant had lower level of lignin, anthocyanin, proanthocyanidin content, and highly increased level of melanin content as compared to wild type. Using RNA-Seq, we examined the seed coat transcriptome in three stages of seed development in the wild type and the pscb mutant. The RNA-Seq analysis revealed presence of highly differentially expressed phenylpropanoid and flavonoid pathway genes in all the three seed development stages, especially at 40 days after flowering (DAF40). Also, the expression of polyphenol oxidases and peroxidase were found to be activated significantly especially in the late seed developmental stage. The genome-wide comparative study of the expression profiles revealed 62 differentially expressed genes common across all the three stages. By analyzing the expression patterns and the sequences of the common differentially expressed genes of the three stages, three candidate genes namely c36498_g1 (CCoAOMT1), c40902_g2 (kinesin) , and c33560_g1 (MYB3) were identified responsible for seed-coat cracking and brown color phenotype. Therefore, this study not only provided candidate genes but also provided greater insights and molecular genetic control of peanut seed-coat cracking and color variation. The information generated in this study will facilitate further identification of causal gene and diagnostic markers for breeding improved peanut varieties with smooth and desirable seed coat color.

  3. Transcriptome analysis of a new peanut seed coat mutant for the physiological regulatory mechanism involved in seed coat cracking and pigmentation

    Directory of Open Access Journals (Sweden)

    Liyun Wan

    2016-10-01

    Full Text Available Seed-coat cracking and undesirable color of seed coat highly affects external appearance and commercial value of peanuts (Arachis hypogaea L.. With an objective to find genetic solution to the above problems, a peanut mutant with cracking and brown colored seed coat (testa was identified from an EMS treated mutant population and designated as peanut seed coat crack and brown color mutant line (pscb. The seed coat weight of the mutant was almost twice of the wild type, and the germination time was significantly lower than wild type. Further, the mutant had lower level of lignin, anthocyanin, proanthocyandin content and highly increased level of melanin content as compared to wild type. Using RNA-Seq, we examined the seed coat transcriptome in three stages of seed development in the wild type and the pscb mutant. The RNA-Seq analysis revealed presence of highly differentially expressed phenylpropanoid and flavonoid pathway genes in all the three seed development stages, especially at 40 days after flowering (DAF40. Also, the expression of polyphenol oxidases and peroxidase were found to be activated significantly especially in the late seed developmental stage. The genome-wide comparative study of the expression profiles revealed 62 differentially expressed genes common across all the three stages. By analyzing the expression patterns and the sequences of the common differentially expressed genes of the three stages, three candidate genes namely c36498_g1 (CCoAOMT1, c40902_g2 (kinesin and c33560_g1 (MYB3 were identified responsible for seed-coat cracking and brown color phenotype. Therefore, this study not only provided candidate genes but also provided greater insights and molecular genetic control of peanut seed-coat cracking and color variation. The information generated in this study will facilitate further identification of causal gene and diagnostic markers for breeding improved peanut varieties with smooth and desirable seed coat color.

  4. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...

  5. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  6. Electrically conductive polymer concrete coatings

    Science.gov (United States)

    Fontana, Jack J.; Elling, David; Reams, Walter

    1990-01-01

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  7. Coated substrate apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Zhenan; Diao, Ying; Mannsfeld, Stefan Christian Bernhardt; Tee, Chee-Keong; Becerril-Garcia, Hector A.; Zhou, Yan

    2018-01-09

    A coated substrate is formed with aligned objects such as small molecules, macromolecules and nanoscale particulates, such as inorganic, organic or inorganic/organic hybrid materials. In accordance with one or more embodiments, an apparatus or method involves an applicator having at least one surface patterned with protruded or indented features, and a coated substrate including a solution-based layer of objects having features and morphology attributes arranged as a function of the protruded or indented features.

  8. Silicone nanocomposite coatings for fabrics

    Science.gov (United States)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  9. Field measurements of AC- and DC-energized silicone elastomer coated outdoor insulators

    Energy Technology Data Exchange (ETDEWEB)

    Soerqvist, T.; Vlastos, A.E. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of High Voltage Engineering

    1995-12-01

    The paper presents a comparison between the leakage currents of bare porcelain insulators and porcelain insulators coated with two types of room temperature vulcanizing (RTV) silicone rubbers. The data presented is based on field measurements of both AC- and DC-energized insulators during salt-storm conditions. A study of the surfaces of the two coatings reveals that one is less hydrophobic than the other. However, there are no large differences in the leakage currents between the insulators coated with the two types of RTV. The leakage current of the RTV-coated insulators remains very low compared to that of the uncoated porcelain insulators under salt-storm conditions. Moreover, the leakage current of the RTV-coated porcelain insulators is comparable to that of the silicone rubber (SIR) insulators which are also studied under the same conditions. 3 refs, 14 figs, 1 tab

  10. Material Science Smart Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A. I. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Sabirianov, R. F. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Namavar, Fereydoon [Univ. of Nebraska Medical Center, Omaha, NE (United States)

    2014-07-01

    The contribution of electrostatic interactions to the free energy of binding between model protein and a ceramic implant surface in the aqueous solvent, considered in the framework of the nonlocal electrostatic model, is calculated as a function of the implant low-frequency dielectric constant. We show that the existence of a dynamically ordered (low-dielectric) interfacial solvent layer at the protein-solvent and ceramic-solvent interface markedly increases charging energy of the protein and ceramic implant, and consequently makes the electrostatic contribution to the protein-ceramic binding energy more favorable (attractive). Our analysis shows that the corresponding electrostatic energy between protein and oxide ceramics depends nonmonotonically on the dielectric constant of ceramic, εC. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate εC below or about 35 (in particularly ZrO2 or Ta2O5). This is in contrast to classical (local) consideration of the solvent, which demonstrates an unfavorable electrostatic interaction of protein with typical metal oxide ceramic materials (εC>10). Thus, a solid implant coated by combining oxide ceramic with a reduced dielectric constant can be beneficial to strengthen the electrostatic binding of the protein-implant complex.

  11. Large area precision optical coatings by pulse magnetron sputtering

    Science.gov (United States)

    Frach, Peter; Gloess, Daniel; Goschurny, Thomas; Drescher, Andy; Hartung, Ullrich; Bartzsch, Hagen; Heisig, Andreas; Grune, Harald; Leischnig, Lothar; Leischnig, Steffen; Bundesmann, Carsten

    2017-05-01

    Pulse magnetron sputtering is very well suited for the deposition of optical coatings. Due to energetic activation during film growth, sputtered films are dense, smooth and show an excellent environmental stability. Films of materials like SiO2, Al2O3, Nb2O5 or Ta2O5 can be produced with very little absorption and scattering losses and are well suited for precision optics. FEP's coating plant PreSensLine, a deposition machine dedicated for the development and deposition of precision optical layer systems will be presented. The coating machine (VON ARDENNE) is equipped with dual magnetron systems (type RM by FEP). Concepts regarding machine design, process technology and process control as well as in situ monitoring are presented to realize the high demands on uniformity, accuracy and reproducibility. Results of gradient and multilayer type precision optical coatings are presented. Application examples are edge filters and special antireflective coatings for the backlight of 3D displays with substrate size up to 300 x 400mm. The machine allows deposition of rugate type gradient layers by rotating a rotary table with substrates between two sources of the dual magnetron system. By combination of the precision drive (by LSA) for the substrate movement and a special pulse parameter variation during the deposition process (available with the pulse unit UBS-C2 of FEP), it is possible to adjust the deposition rate as a function of the substrate position exactly. The aim of a current development is a technology for the uniform coating of 3D-substrates and freeform components as well as laterally graded layers.

  12. Fluidized-Bed Coating with Sodium Sulfate and PVA-TiO2, 2. Influence of Coating Solution Viscosity, Stickiness, pH, and Droplet Diameter on Agglomeration

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, Poul; Jensen, Anker Degn

    2009-01-01

    In the first part of this study [Hede, P. D.; Bach, P.; Jensen, A. D. Ind. Eng. Chem. Res. 2009, 49, 1914], agglomeration regime maps were developed for two types of coatings: sodium sulfate and PVA-TiO2. It was observed here how the agglomeration tendency is always lower for the salt coating...... the PVA-TiO2 coating formulation and process to achieve a low tendency of agglomeration, similar to that of the salt coating process. The best results for the PVA-TiO2 solution are obtained by substituting the PVA-TiO2 in equal amounts with Neodol 23-6.5 and further reducing the pH value in the coating...

  13. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  14. 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.

  15. Switchable antifouling coatings and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Michele L. Baca; Dirk, Shawn M.; Johnson, Ross Stefan

    2017-02-28

    The present invention relates to antifouling coatings capable of being switched by using heat or ultraviolet light. Prior to switching, the coating includes an onium cation component having antimicrobial and antibacterial properties. Upon switching, the coating is converted to a conjugated polymer state, and the cationic component is released with any adsorbed biofilm layer. Thus, the coatings herein have switchable and releasable properties. Methods of making and using such coatings are also described.

  16. Improved Corrosion Resistance of a Heat Exchanger Using a Copper Tube Coated with Tin

    National Research Council Canada - National Science Library

    FUKUSHIMA, Makoto; YONESAKI, Takahiro; TAKIZAWA, Kikuo; SUSAI, Takashi

    2000-01-01

      The outer face of copper tubes used in a heat exchanger were coated with tin. The tubes were brazed with various types of solder in order to evaluate their corrosion resistance in a H2S gas environment...

  17. Evaluation of Hydrogen Cracking in Weld Metal Deposited using Cellulosic-Coated Electrodes

    Science.gov (United States)

    2009-06-16

    Cellulosic-coated electrodes (primarily AWS EXX10-type) are traditionally used for "stovepipe" welding of pipelines because they are well suited for deposition of pipeline girth welds and are capable of high deposition rates when welding downhill. De...

  18. Low-Stress Iridium Coatings for Thin-Shell X-Ray Telescopes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and commercialize a new type of low-stress iridium (Ir) X-ray mirror coating technology that can be used for the construction of...

  19. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  20. Water-thinnable polymers for durable coatings for different materials

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Piotr, E-mail: piotr.jankowski@ichp.pl; Kijowska, Dorota, E-mail: piotr.jankowski@ichp.pl [Industrial Chemistry Research Institute, Department of Polyesters, Epoxides and Polyurethanes, 8 Rydygiera Str., 01-793 Warszawa (Poland)

    2014-05-15

    The methods of obtaining water-thinnable polymers - water-thinnable unsaturated polyester resins (WTUPR) - by polycondensation were elaborate and optimized. As hydrophilic monomers different types of sulfonate monomers were used. The monomers, with sulfonate groups and other reactive groups, were obtained by sulfonation of organic compounds with satisfactory yield. All products were analyzed by {sup 1}H NMR and {sup 13}C NMR spectra. WTUPR were used as polymeric binders for coatings applications. Coatings with relatively high pendulum hardness, good properties and durability, useful for practical applications, were obtained. Typical existing equipment for the production of unsaturated polyester resins can be applied for the industrial preparation of WTUPR.

  1. Coated Pit-mediated Endocytosis of the Type I Transforming Growth Factor-β (TGF-β) Receptor Depends on a Di-leucine Family Signal and Is Not Required for Signaling*

    Science.gov (United States)

    Shapira, Keren E.; Gross, Avner; Ehrlich, Marcelo; Henis, Yoav I.

    2012-01-01

    The roles of transforming growth factor-β (TGF-β) receptor endocytosis in signaling have been investigated in numerous studies, mainly through the use of endocytosis inhibitory treatments, yielding conflicting results. Two potential sources for these discrepancies were the pleiotropic effects of a general blockade of specific internalization pathways and the scarce information on the regulation of the endocytosis of the signal-transducing type I TGF-β receptor (TβRI). Here, we employed extracellularly tagged myc-TβRI (wild type, truncation mutants, and a series of endocytosis-defective and endocytosis-enhanced mutants) to directly investigate the relationship between TβRI endocytosis and signaling. Our findings indicate that TβRI is targeted for constitutive clathrin-mediated endocytosis via a di-leucine (Leu180-Ile181) signal and an acidic cluster motif. Using Smad-dependent transcriptional activation assays and following Smad2/3 nuclear translocation in response to TGF-β stimulation, we show that TβRI endocytosis is dispensable for TGF-β signaling and may play a role in signal termination. Alanine replacement of Leu180-Ile181 led to partial constitutive activation of TβRI, resulting in part from its retention at the plasma membrane and in part from potential alterations of TβRI regulatory interactions in the vicinity of the mutated residues. PMID:22707720

  2. Effect of Atmospheric and Laboratory Irradiation on Attenuated Total Reflectance Spectra of Organic Coatings

    Science.gov (United States)

    1975-11-01

    COMIPLETING FORM IREPORT NUMBER 21 GOVT ACCESSION NO, 3, RECIPIENT’S CATALOG NUMBER TN-1411 DN744070 4 T IT LE (-d S.b,II.) 5 TYPE OF REPORT & PERIOD...1, blod . ,...15-1* Photodegradation, organic coatings, ATR spectroscopy, atmospheric exposure, xenon-arc irradiation, mercury-arc irradiation, clear...environments followed by visual inspection of the results. The goal of the CEL investigations was to determine what types of changes occur in coatings that

  3. Spacecraft thermal control coatings

    Science.gov (United States)

    Guillaumon, Jean-Claude; Paillous, Alain

    1992-01-01

    The Experiment AO 138-6 was located on the trailing edge of the Long Duration Exposure Facility as part of the French Cooperative Payload (FRECOPA) Experiment. It was purely passive in nature: material specimens 2 x 2 cm, independently mounted in sample-holders, with their surface in the same reference plane, were exposed to space. Thirty samples were set in a vacuum-tight canister which was opened in space a few days after LDEF deployment and closed while still in orbit ten months later; twenty-four samples were directly exposed to space for the total flight duration (preflight handling, shuttle bay environment, separation from shuttle, shuttle environment, LEO environment, docking, descent, transfer to KSC). Materials included paints (conductive or nonconductive), SSM's, polymeric films, surface coatings, composite materials, and metals. After sample retrieving, inspection and measurements were carried out in atmospheric laboratory conditions on each sample: observation with binocular lenses and scanning electron microscopy, spectral relectance and transmittance using an integrating sphere in the wavelength range 280-2300 nm, emissivity by the means of a Gier & Dunkle portable reflectometer, electron spectroscopy for chemical analysis-x-ray photoelectron spectroscopy (ESCA-XPS), and Rutherford backscattering spectroscopy (RBS) measurements on some selected samples. The results obtained from flight were compared to laboratory data obtained in UV-irradiation tests when these data were available. As a general statement a good spectral concordance is observed for all samples not in the canister so long as air recoveries are taken into account. For one material, the degradation is more important for the sample in the canister than for those of the same material mounted at the surface of the tray; for most samples in the canister the degradation is slightly higher than the one which can be predicted from laboratory standard irradiations. Contamination problems having

  4. Influence of semiconducting properties of nanoparticle coating on the electrochemical actuation of liquid metal marble

    Science.gov (United States)

    Sivan, Vijay; Tang, Shi-Yang; O'Mullane, Anthony P.; Petersen, Phred; Kalantar-zadeh, Kourosh; Khoshmanesh, Khashayar; Mitchell, Arnan

    2014-09-01

    Semiconducting properties of nanoparticle coating on liquid metal marbles can present opportunities for an additional dimension of control on these soft objects with functional surfaces in aqueous environments. We show the unique differences in the electrochemical actuation mechanisms of liquid metal marbles with n- and p-type semiconducting nanomaterial coating. A systematic study on such liquid metal marbles shows voltage dependent nanoparticle cluster formation and morphological changes of the liquid metal core during electrochemical actuations and these observations are unique to p-type nanomaterial coated liquid metal marbles.

  5. Utilization of calcite produced in Turkey for paper coating

    Directory of Open Access Journals (Sweden)

    Hüdaverdi Eroğlu

    2002-03-01

    Full Text Available Calcium carbonate is one of the coating pigments widely used in paper industry. Especially, in recent years calcium carbonate filler has gained high importance in alkaline pulping. In Turkey industry actually imports calcium carbonate; whereas, there are rich calcite reservoirs in the country. In this study two different types of domestic ground (GCC calcite samples were used. Physical and chemical properties of calcite samples were tested firstly. CaCO3 percentages of both samples were 97.3 % and 97.6 % (min. 95 % CaCO3. MgCO3 and Fe2O3 percentages were within the desired limits. Brightness values were 95.5 % and 94.5 % and yellowness 1.1 % and 1.5 % elrepho. These values also were within the requested limits. Under 2 microns particle size and over 10 microns particle size fractions were 95 % and 89 % (min. 80 and 1 % and 2 % (max. 2 respectively. Dry matter rates were between 40 %-65 %, for the pilot plant-coating machine. During the preparation of coating color calcium carbonate has been used together with kaolin. The ratios of calcium carbonate to kaolin were 30/70, 40/60, 50/50, 60/40, 70/30, 100/0. In coating color preparation latex was used as a binder because of its wide applications. Latex percentages were 11, 12, and 13 %. Coated papers were glossed and physically tested. As a result, both calcium carbonate samples were found suitable for using in coating color preparation. By the utilization of domestic calcium carbonate in coated paper production, there will be foreign currencies saving.

  6. Length of winter coat in horses depending on husbandry conditions.

    Science.gov (United States)

    Bocian, Krzysztof; Strzelec, Katarzyna; Janczarek, Iwona; Jabłecki, Zygmunt; Kolstrung, Ryszard

    2017-02-01

    This paper analyzes changes in the length of coat on selected body areas in horses and ponies kept under different husbandry (stable) conditions during the winter-spring period. The study included 12 Małpolski geldings and 12 geldings of Felin ponies aged 10-15 years. Horses were kept in two stables (six horses and six ponies in each stable). The type of performance, husbandry conditions and feeding of the studied animals were comparable. As of December 1, samples of hair coat from the scapula, sternum, back and abdomen areas of both body sides were collected seven times. The lengths of 20 randomly selected hair fibers were measured. Daily measurements of air temperature in the stables were also taken. An analysis of variance (ANOVA) was performed using the following factors: the body part from where the coat was sampled, the subsequent examination and the stable as well as the interaction between these factors. The significance of differences between means was determined with a t-Tukey test. The relations between air temperature in the stable and hair length were calculated using Pearson's correlation. It was found that air temperature in the stable impacts the length of winter coat in horses and ponies. The effect of this factor is more pronounced in ponies; as in the stables with lower temperatures it produces a longer hair coat which is more evenly distributed over the body in comparison with horses. Keeping horses and ponies in stables with a low air temperature accelerates coat shedding by approximately 25 days. Coat shedding begins from the scapula area. © 2016 Japanese Society of Animal Science.

  7. Effect of gun current on the microstructure and crystallinity of plasma sprayed hydroxyapatite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Morks, M.F. [Joining and Welding Research Institute, 11-1 Mihogaoka, Ibaraki, 567-0047 Osaka (Japan)]. E-mail: magdimorks@hotmail.com; Kobayashi, A. [Joining and Welding Research Institute, 11-1 Mihogaoka, Ibaraki, 567-0047 Osaka (Japan)

    2007-06-30

    Hydroxyapatite (HA) is a bioactive material because its chemical structure is close to the natural bone. Its bioactive properties make it attractive material in biomedical applications. Gas tunnel type plasma spraying (GTPS) technique was employed in the present study to deposit HA coatings on SUS 304 stainless steel substrate. GTPS is composed of two plasma sources: gun which produces internal low power plasma (1.3-8 kW) and vortex which produces the main plasma with high power level (10-40 kW). Controlling the spraying parameters is the key role for spraying high crystalline HA coatings on the metallic implants. In this study, the arc gun current was changed while the vortex arc current was kept constant at 450 A during the spraying process of HA coatings. The objective of this study is to investigate the influence of gun current on the microstructure, phase crystallinity and hardness properties of HA coatings. The surface morphology and microstructure of as-sprayed coatings were examined by scanning electron microscope. The phase structure of HA coatings was investigated by X-ray diffraction analysis. HA coatings sprayed at high gun current (100 A) are dense, and have high hardness. The crystallinity of HA coatings was decreased with the increasing in the gun current. On the other hand, the hardness was slightly decreased and the coatings suffer from some porosity at gun currents 0, 30 and 50 A.

  8. Microstructural characterization of radio frequency and direct current plasma-sprayed Al2O3 coatings

    Science.gov (United States)

    Chen, H. C.; Pfender, E.; Dzur, B.; Nutsch, G.

    2000-06-01

    Microstructures of radio frequency (RF) and direct current (DC) plasma-sprayed Al2O3 coatings deposited onto steel substrates were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), electron microprobe analysis (EMPA), polarizing optical microscopy (OM), and transmission electron microscopy (TEM). Because RF and DC plasmas produce different particle heating and acceleration, the morphology, phase structure, and fracture modes of the coatings vary substantially. In the case of RF coatings, a clear lamellar microstructure with relatively thick lamellae was observed, which is due to the large particles and the low particle velocities, with α-Al2O3 as the predominant phase and with delamination type of fracture detected on the fracture surface. In contrast, the DC coatings consisted of predominantly metastable γ-Al2O3 as well as amorphous phases, with a mixed fracture mode of the coating observed. In spite of limited interfacial interdiffusion detected by EMPA, TEM showed an interfacial layer existing at the interface between the coating and the substrate for both cases. For RF coatings, the interfacial layer on the order of 1 µm was composed of three sublayers, each of which was different in composition and morphology. However, the interfacial layer for the DC coating consisted primarily of an amorphous phase, containing both coating and substrate materials with or without platelike microcrystals; although in some regions a thick amorphous Al2O3 layer was in direct contact with the substrate.

  9. Study of Selected Properties of Thermally Sprayed Coatings Containing WC and WB Hard Particles

    Directory of Open Access Journals (Sweden)

    Brezinová Janette

    2016-12-01

    Full Text Available The paper presents results of research of the essential characteristics of two kinds of advanced coatings applied by HVOF technology. One studied coating: WB-WC-Co (60-30-10% contains two types of hard particles (WC and WB, the second coating is eco-friendly alternative to the previously used WC-based coatings, called “green carbides” with the composition WC-FeCrAl (85-15%. In green carbides coating the heavy metals (Co, Ni, NiCr forming the binding matrix in conventional wear-resistant coatings are replaced by more environmentally friendly matrix based on FeCrAl alloy. On the coatings was carried out: metallographic analysis, measurement of thickness, micro-hardness, adhesion, resistance to thermal cyclic loading and adhesive wear resistance (pin-on-disk test. One thermal cycle consisted of heating the coatings to 600°C, dwell for 10 minutes, and subsequently cooling on the still air. The number of thermal cycles: 10. The base material was stainless steel AISI 316L, pretreatment prior to application of the coating: blasting with white corundum, application device JP-5000.

  10. Aspects of Characterisation of Thin Coating Adhesion at the Nano-Scale

    Institute of Scientific and Technical Information of China (English)

    Jisheng E; Aiyang Zhang; Ben D. Beake

    2002-01-01

    In response to current development of materials in nano-science,characterisation of thin coating adhesion on a nano-scale becomes one of the most important research areas,as new coatings get ever thinner and more technologically advanced. With a review of technology and mechanisms of evaluating the adhesion failure of coatings,three techniques,nano impact ,nano-scratch and nano-indentation techniques ,for charactering the adhesion of thin coatings on a nano scale are described.Results of charactering the adhesion faliure of thin coatings using three different techniques indicate that the nano-scratch and nano-indentation techniques are very useful tools ,particularly in charactering the performance of thin coatings under nano-abra sive wear conditions. However,results from these types of tests cannot be easily applied to predict the performance of coatings whose are subject to nano-erosive wear,cyclic nano-fatigue or multiple nano-impacts during service. Instead,results of the new dynamic testing technique ,impact technique ,are found to correlate well with the coating performance under fatigue conditions,precisely because the impact test more closely simulates the actual contact (adhesion failure and wear)conditions of thin coatings occurring in nano-erosive/nano-fatigue/nano-impact wear.

  11. Wettability and corrosion of alumina embedded nanocomposite MAO coating on nanocrystalline AZ31B magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gheytani, M.; Aliofkhazraei, M., E-mail: maliofkh@gmail.com; Bagheri, H.R.; Masiha, H.R.; Rouhaghdam, A. Sabour

    2015-11-15

    In this paper, micro- and nanocrystalline AZ31B magnesium alloy were coated by micro-arc oxidation method. In order to fabricate nanocrystalline surface layer, surface mechanical attrition treatment was performed and nano-grains with average size of 5–10 nm were formed on the surface of the samples. Coating process was carried out at different conditions including two coating times and two types of electrolyte. Alumina nanoparticles were utilized as suspension in electrolyte to form nanocomposite coatings by micro-arc oxidation method. Potentiodynamic polarization, percentage of porosity, and wettability tests were performed to study various characteristics of the coated samples. The results of scanning electron microscope imply that samples coated in silicate-based electrolyte involve much lower surface porosity (∼25%). Besides, the results of wettability test indicated that the maximum surface tension with deionized water is for nanocrystalline sample. In this regard, the sample coated in silicate-based suspension was 4 times more hydrophilic than the microcrystalline sample. - Highlights: • MAO in phosphate electrolyte needs higher energy as compared to silicate electrolyte. • Less porosity and finer grain size on free surface of the silicate-based coatings. • Observed porosity from top surface of coating shows the effect of the final MAO sparks. • SMAT affects surface roughness and accelerates growth kinetics.

  12. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  13. Development of the M2A1 Container Coatings ECP

    Science.gov (United States)

    2010-02-11

    52891 Acrylic E-Coat Urethane Powder Results APPLICATION Low End One-Coat Dip Enamel High End One-Coat Electrocoat High End One-Coat Top Coat Cure...Properties Data MIL-E-52891 Acrylic E-Coat Urethane Powder Results APPLICATION Low End One-Coat Dip Enamel High End One-Coat Electrocoat High End One-Coat...To complete a finishing cost analysis for painting ammunition containers. Compare equipment, layout and operating costs for Electrocoat and powder

  14. Development of chitosan-based antimicrobial leather coatings.

    Science.gov (United States)

    Fernandes, Isabel P; Amaral, Joana S; Pinto, Vera; Ferreira, Maria José; Barreiro, Maria Filomena

    2013-10-15

    The development of antimicrobial coatings for footwear components is of great interest both from industry and consumer's point of view. In this work, antimicrobial leather materials were developed taking advantage of chitosan intrinsic antimicrobial activity and film forming capacity. Considering the specificities of the leather tanning industry, different coating technologies, namely drum, calender and spray, were tested, being the best results achieved with the drum. This last approach was further investigated to assess the effect of chitosan content, type of solubilizing acid, and impregnation time on the achieved antimicrobial capacity. Considering chitosan price (economic reasons) and the obtained results (antimicrobial activity and coating effectiveness, as inspected by SEM), the impregnation in the drum using a chitosan content of 1% (w/v) in a formic acid solution during 2h, is proposed as the best option for obtaining leather with antimicrobial capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Mussel-inspired dendritic polymers as universal multifunctional coatings.

    Science.gov (United States)

    Wei, Qiang; Achazi, Katharina; Liebe, Hendrik; Schulz, Andrea; Noeske, Paul-Ludwig Michael; Grunwald, Ingo; Haag, Rainer

    2014-10-20

    A rapid and universal approach for multifunctional material coatings was developed based on a mussel-inspired dendritic polymer. This new kind of polymer mimics not only the functional groups of mussel foot proteins (mfps) but also their molecular weight and molecular structure. The large number of catechol and amine groups set the basis for heteromultivalent anchoring and crosslinking. The molecular weight reaches 10 kDa, which is similar to the most adhesive mussel foot protein mfp-5. Also, the dendritic structure exposes its functional groups on the surface like the folded proteins. As a result, a very stable coating can be prepared on virtually any type of material surface within 10 min by a simple dip-coating method, which is as fast as the formation of mussel byssal threads in nature. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Titania-coated manganite nanoparticles: Synthesis of the shell, characterization and MRI properties

    Energy Technology Data Exchange (ETDEWEB)

    Jirák, Zdeněk; Kuličková, Jarmila [Institute of Physics, AS CR, Cukrovarnická 10, 162 00 Praha 6 (Czech Republic); Herynek, Vít [Institute for Clinical and Experimental Medicine, Vídeňská 1958/9, 140 21 Praha 4 (Czech Republic); Maryško, Miroslav [Institute of Physics, AS CR, Cukrovarnická 10, 162 00 Praha 6 (Czech Republic); Koktan, Jakub [Institute of Physics, AS CR, Cukrovarnická 10, 162 00 Praha 6 (Czech Republic); University of Chemistry and Technology, Prague, Technická 5, 166 28 Praha 6 (Czech Republic); Kaman, Ondřej, E-mail: kamano@seznam.cz [Institute of Physics, AS CR, Cukrovarnická 10, 162 00 Praha 6 (Czech Republic)

    2017-04-01

    Novel procedure for coating of oxide nanoparticles with titania, employing hydrolysis and polycondensation of titanium alkoxides under high-dilution conditions and cationic surfactants, is developed and applied to magnetic cores of perovskite manganite. Bare particles of the ferromagnetic La{sub 0.65}Sr{sub 0.35}MnO{sub 3} phase, possessing high magnetization, M{sub 10} {sub kOe}(4.5 K) = 63.5 emu g{sup −1}, and Curie temperature, T{sub C} = 355 K, are synthesized by sol-gel procedure and subsequently coated with titania. Further, a comparative silica-coated product is prepared. In order to analyse the morphology, colloidal stability, and surface properties of these two types of coated particles, a detailed study by means of transmission electron microscopy, dynamic light scattering, zeta-potential measurements, and IR spectroscopy is carried out. The experiments on the titania-coated sample reveal a continuous though porous character of the TiO{sub 2} shell, the nature of which is amorphous but can be transformed to anatase at higher temperatures. Finally, the relaxometric study at the magnetic field of 0.5 T, performed to quantity the transverse relaxivity and its temperature dependence, reveals important differences between the titania-coated and silica-coated nanoparticles. - Highlights: • Magnetic nanoparticles of perovskite La{sub 0.65}Sr{sub 0.35}MnO{sub 3} phase are coated with TiO{sub 2}. • The titania forms a continuous and amorphous shell and provides colloidal stability. • Morphology and surface properties are compared to a silica-coated product. • MRI properties of both the titania- and silica-coated particles are studied at 0.5 T. • The temperature dependence of r{sub 2} is strongly affected by the type of coating.

  17. A Cross Sectional Study of Microbial Contamination of Medical Students’ White Coat

    Directory of Open Access Journals (Sweden)

    Muhadi, S. A.

    2007-01-01

    Full Text Available The objective of this study is to determine the incidence of microbial contamination on medical students’ white coats, the way they handle and clean their white coats and their perception towards contamination. For this purpose, cross sectional survey of the bacterial contamination of white coats in a medical college has been carried out in 3 different locations; Royal College of Medicine, Perak, University of Kuala Lumpur and a private college attached to Ipoh General Hospital. It was found that the incidence of Staphylococus aureus, was 32% on short-sleeved and 54% on long-sleeved white coats. Bacillus species was the second most common type of bacteria found. Male collars and female pockets had higher microbial contaminations (p=0.01, 0.03 respectively. Clinical students’ white coats were significantly less contaminated than non-clinical students (p=0.001 although they tend to wear it for a longer period (5.75 ± 2.19 h vs. 2.32 ± 0.81 h (p=0.001. Clinical students owned more short-sleeved coats (p=0.001 and washed their coats more often (p=0.01 than non-clinical ones. More than eighty one percent of clinical students wear their white coats in the college the majority of whom were females (p=0.005. Perception of clinical and non-clinical students towards white coat contamination was similar. Medical students’ white coats are contaminated with bacteria and they are potentially source of cross infection. Student’s way of handling and washing white coats should be corrected by issuing and following standard guidelines. Students should be bared from wearing white coats in non-clinical areas. Washing hands and using plastic aprons is highly recommended before examining wounds.

  18. Ion Beam Sputtered Coatings of Bioglass

    Science.gov (United States)

    Hench, Larry L.; Wilson, J.; Ruzakowski, Patricia Henrietta Anne

    1982-01-01

    The ion beam sputtering technique available at the NASA-Lewis was used to apply coatings of bioglass to ceramic, metallic, and polymeric substrates. Experiments in vivo and in vitro described investigate these coatings. Some degree of substrate masking was obtained in all samples although stability and reactivity equivalent to bulk bioglass was not observed in all coated samples. Some degree of stability was seen in all coated samples that were reacted in vitro. Both metallic and ceramic substrates coated in this manner failed to show significantly improved coatings over those obtained with existing techniques. Implantation of the coated ceramic substrate samples in bone gave no definite bonding as seen with bulk glass; however, partial and patchy bonding was seen. Polymeric substrates in these studies showed promise of success. The coatings applied were sufficient to mask the underlying reactive test surface and tissue adhesion of collagen to bioglass was seen. Hydrophilic, hydrophobic, charged, and uncharged polymeric surfaces were successfully coated.

  19. Kinetic regulation of coated vesicle secretion

    CERN Document Server

    Foret, Lionel

    2008-01-01

    The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also tri...

  20. 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

  1. Poly (lactic acid organoclay nano composites for paper coating applications

    Directory of Open Access Journals (Sweden)

    Tatcha Sonjui

    2014-10-01

    Full Text Available Poly(lactic acid or PLA is a well-known biodegradable polymer derived from renewable resources such as corn strach, tapioca strach, and sugar cane. PLA is the most extensively utilized biodegradable polyester with potential to replace conventional petrochemical-based polymers. However, PLA has some drawbacks, such as brittleness and poor gas barrier properties. Nano composite polymers have experience and increasing interest due to their characteristics, especially in mechanical and thermal properties. The objectives of this research were to prepare PLA formulations using three different PLAs. The formulas giving high gloss coating film were selected to prepare nano composite film by incorporated with different amount of various types of organoclays. The physical properties of the PLA coating films were studied and it was found that the PLA 7000D with 0.1%w/w of Cloisite 30B provided decent viscosity for coating process. In addition, the nano composite coating films showed good physical properties such as high gloss, good adhesion, and good hardness. There is a possibility of using the obtained formulation as a paper coating film.

  2. Metal Ir coatings on endocardial electrode tips, obtained by MOCVD

    Science.gov (United States)

    Vikulova, Evgeniia S.; Kal'nyi, Danila B.; Shubin, Yury V.; Kokovkin, Vasily V.; Morozova, Natalya B.; Hassan, Aseel; Basova, Tamara V.

    2017-12-01

    The present work demonstrates the application of the Metal-Organic Chemical Vapor Deposition technique to fabricate metal iridium coatings onto the pole tips of endocardial electrodes. Using iridium (III) acetylacetonate as a volatile precursor, the target coatings were successfully applied to the working surface of cathodes and anodes of pacemaker electrodes in the flow type reactor in hydrogen atmosphere at deposition temperature of 550 °C. The coating samples were characterized by means of XRD, SEM, Raman- and XPS-spectroscopies. The formation of non-textured coatings with fractal-like morphology and 7-24 nm crystallite size has been realized. The electrochemical properties of the coatings were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The charge storage capacity values of the electrochemically activated samples were 17.0-115 mC cm-2 and 14.4-76.5 mC cm-2 for measurements carried out in 0.1 M sulfuric acid and in phosphate buffer saline solutions, respectively. A comparison of some characteristics of the samples obtained with commercially available cathode of pacemaker electrodes is also presented.

  3. Addressing stress corrosion cracking on multi layer pipeline coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Scott B.; Marr, James E. [Tuboscope Pipeline Services, Houston, TX (United States); Willmot, Martyn [Jotun Group (Norway); Norman, David [David Norman Corrosion Control, Cornwall (United Kingdom); Khera, Ashish [Allied Engineering, Portland, ME (United States)

    2005-07-01

    Stress corrosion cracking (SCC) is now recognized by operators worldwide as a significant threat to the safe operation of their pipeline systems. Gas, oil, and refined products lines have all been susceptible to this form of environmentally assisted cracking. As a result, operators and regulators have been incorporating data related to the development and prevalence of SCC into their risk management systems in order that they may effectively address this time-dependant threat. The National Association of Corrosion Engineers (NACE) published the first structured methodology for stress corrosion cracking direct assessment (SCCDA) in 2004 (RP0204-2004). Operators are now beginning to apply the methods outlined in the standard to assess their systems. Research and industry experience have shown that various pipeline coating systems can be more or less effective in preventing the formation and growth of SCC. Newer pipeline coatings, such as multi layer epoxy/extruded polyolefin systems have been widely regarded as effective coating systems to address the threat posed by SCC when they are properly applied. New field studies performed on a pipeline coated with a three layer epoxy/polyethylene system have raised the possibility that operators utilizing these types of coatings may need to reassess how they manage the SCC threat. (author)

  4. Anodic-modified anticorrosive coatings

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2011-01-01

    Full Text Available Steel machine parts are exposed to electrochemical corrosion. This applies to many environments including atmosphere, soil, water, and even various fertilizers. High-carbon steel and low-alloyed steel are not stable (in terms of thermo-dynamics, do not feature effective passivation, and even the corrosion products do not form a stable protection layer. As a result, special anti-corrosion protection is critical. In heavy-corrosion environment, paint systems containing Zn have proven to be very effective. Presented text describes verification of paint systems with high Zn content and compares them to galvanic Zn coatings. Steel samples with protective coatings have been tested in condensation chamber with neutral salt-spray. This way, corrosion resistance of Zn-rich paint systems and galvanic Zn coatings has been evaluated and compared. Galvanic Zn-coatings have shown complete decomposition during the chamber exposition. Thus, further testing was adopted for paint systems only with a special attention being paid to gradual degradation of anti-corrosion layer. Final part of the text lists reasons of coating degradation process and outlines possible solutions of the issue.

  5. Electrochemical Study of Polymer and Ceramic-Based Nanocomposite Coatings for Corrosion Protection of Cast Iron Pipeline

    Directory of Open Access Journals (Sweden)

    Ameen Uddin Ammar

    2018-02-01

    Full Text Available Coating is one of the most effective measures to protect metallic materials from corrosion. Various types of coatings such as metallic, ceramic and polymer coatings have been investigated in a quest to find durable coatings to resist electrochemical decay of metals in industrial applications. Many polymeric composite coatings have proved to be resistant against aggressive environments. Two major applications of ferrous materials are in marine environments and in the oil and gas industry. Knowing the corroding behavior of ferrous-based materials during exposure to these aggressive applications, an effort has been made to protect the material by using polymeric and ceramic-based coatings reinforced with nano materials. Uncoated and coated cast iron pipeline material was investigated during corrosion resistance by employing EIS (electrochemical impedance spectroscopy and electrochemical DC corrosion testing using the “three electrode system”. Cast iron pipeline samples were coated with Polyvinyl Alcohol/Polyaniline/FLG (Few Layers Graphene and TiO2/GO (graphene oxide nanocomposite by dip-coating. The EIS data indicated better capacitance and higher impedance values for coated samples compared with the bare metal, depicting enhanced corrosion resistance against seawater and “produce water” of a crude oil sample from a local oil rig; Tafel scans confirmed a significant decrease in corrosion rate of coated samples.

  6. Electrochemical Study of Polymer and Ceramic-Based Nanocomposite Coatings for Corrosion Protection of Cast Iron Pipeline.

    Science.gov (United States)

    Ammar, Ameen Uddin; Shahid, Muhammad; Ahmed, Muhammad Khitab; Khan, Munawar; Khalid, Amir; Khan, Zulfiqar Ahmad

    2018-02-25

    Coating is one of the most effective measures to protect metallic materials from corrosion. Various types of coatings such as metallic, ceramic and polymer coatings have been investigated in a quest to find durable coatings to resist electrochemical decay of metals in industrial applications. Many polymeric composite coatings have proved to be resistant against aggressive environments. Two major applications of ferrous materials are in marine environments and in the oil and gas industry. Knowing the corroding behavior of ferrous-based materials during exposure to these aggressive applications, an effort has been made to protect the material by using polymeric and ceramic-based coatings reinforced with nano materials. Uncoated and coated cast iron pipeline material was investigated during corrosion resistance by employing EIS (electrochemical impedance spectroscopy) and electrochemical DC corrosion testing using the "three electrode system". Cast iron pipeline samples were coated with Polyvinyl Alcohol/Polyaniline/FLG (Few Layers Graphene) and TiO₂/GO (graphene oxide) nanocomposite by dip-coating. The EIS data indicated better capacitance and higher impedance values for coated samples compared with the bare metal, depicting enhanced corrosion resistance against seawater and "produce water" of a crude oil sample from a local oil rig; Tafel scans confirmed a significant decrease in corrosion rate of coated samples.

  7. Tungsten oxide coatings deposited by plasma spray using powder and solution precursor for detection of nitrogen dioxide gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao, E-mail: zhangc@yzu.edu.cn [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Wang, Jie [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Geng, Xin [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China)

    2016-05-25

    Increasing attention has been paid on preparation methods for resistive-type gas sensors based on semiconductor metal oxides. In this work, tungsten oxide (WO{sub 3}) coatings were prepared on alumina substrates and used as gas sensitive layers. The coatings were deposited by atmospheric plasma spray using powder, solution precursor, or a combination of both. Tungsten oxide powder through a powder port and ammonium tungstate aqueous solution through a liquid port were injected into plasma stream respectively or together to deposit WO{sub 3} coatings. Phase structures in the coatings were characterized by X-ray diffraction analyzer. The field-emission scanning electron microscopy images confirmed that the coatings were in microstructure, nanostructure or micro-nanostructure. The sensing properties of the sensors based on the coatings exposed to 1 ppm nitrogen dioxide gas were characterized in a home-made instrument. Sensing properties of the coatings were compared and discussed. The influences of gas humidity and working temperature on the sensor responses were further studied. - Highlights: • Porous gas sensitive coatings were deposited by plasma spray using powder and solution precursor. • Crystallized WO{sub 3} were obtained through hybrid plasma spray plus a pre-conditioned step. • Plasma power had an important influence on coating microstructure. • The particle size of atmospheric plasma-sprayed microstructured coating was stable. • Solution precursor plasma-sprayed WO{sub 3} coatings had nanostructure and showed good responses to 1 ppm NO{sub 2}.

  8. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  9. Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

    OpenAIRE

    Fernandes, Kirlene Salgado; Alvarenga,Evandro de Azevedo; Brandão,Paulo Roberto Gomes; Lins,Vanessa de Freitas Cunha

    2011-01-01

    Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electropainting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are i...

  10. Identification of urushi coated films taken from ancient Buddha images by using PIXE, FT-IR, and organic elemental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kagemori, N.; Umemura, K.; Yoshimura, T.; Inoue, M.; Kawai, S. [Wood Research Institute, Kyoto Univ., Uji, Kyoto (Japan); Yano, K. [Tokyo National University of Fine Arts and Music, Uenokouen, Tokyo (Japan); Sera, K. [Cyclotron Research Center, Iwate Medical Univ., Takizawa, Iwate (Japan); Futatsugawa, S. [Nishina Memorial Cyclotron Center, Japan Radioisotope Association, Takizawa, Iwate (Japan); Nakamura, Y. [Kyoto National Museum, Higashiyama, Kyoto (Japan)

    1999-07-01

    Six types of samples including urushi, urushi tree and black coating films taken from ancient Buddha images were examined by analyses of PIXE, organic element and FT-IR to identify with urushi or another material. Based on the results of three analytical experiments above mentioned, the coating materials aging over hundreds of years were identified with weathered urushi films mixed with other material. Further investigation may reveal the urushi coating techniques used in the past. (author)

  11. Thermomechanical behaviour of thermal barrier coatings. Thermal Barrier Coatings II - interim report; Haltbarkeit thermomechanisch belasteter Waermedaemmschichtsysteme. Waermedaemmschichtsysteme II - Zwischenbericht

    Energy Technology Data Exchange (ETDEWEB)

    Berger, C.; Schmidt, A. [Technische Univ. Darmstadt (DE). Inst. fuer Werkstoffkunde (IFW); Scholz, A.; Stamm, W. [Siemens Power AG, Muelheim/Ruhr (Germany)

    2004-07-01

    The thermomechanical behaviour of thermal barrier coatings (TBCs) is being investigated by strain controlled service-type thermomechanical fatigue (TMF) tests in order to simulate creep fatigue life of coatings on gas turbine blades. A first service-type cycle with a cycle period of 20 min, a maximum temperature of 930 C and a minimum temperature of 60 C for industrial gas turbines and a second cycle with a cycle period of 8 min, a maximum temperature of 1050 C and a minimum temperature of 300 C for aero engine gas turbines are applied. A special test technique was developed for hollow test pieces with a component typical wall thickness of 1.8 mm made of a single crystal alloy. Different bondcoats (MCrAIY and PtAI) and an air plasma sprayed (APS-) topcoat as well as electron beam (EB-PVD) topcoat are under investigation. After each specific experiment microstructural investigation is used for damage characterisation. The growth of oxides together with thermal mismatch could be identified as the most important damaging effects. Data from long-term Pre-Oxidation experiments allows to adjust the thickness of the TGO for each specific TMF-experiment. The main objective is to ideal with the influence of different bond coat morphologies on the durability of the thermal barrier coating (TBC-) system. The influence of surface roughness, grain size in the bond coat as well as different bond coats (MCrAIY and PtAI) are investigated. First results show that the surface roughness may have a larger influence on the durability of the TBC-system than initially expected. In order to gain deeper understanding of the damaging mechanisms, finite elements calculations are performed to simulate critical local deformation in the TBC-system. The experiments allow deep insight into the damaging mechanisms governing TBC-systems under service-type conditions and thus are suitable for life time prediction TBC-systems. Although a lot of research has been done on this topic. The influence of

  12. Hexavalent Chrome Free Coatings for Electronics; Electromagnetic Interference (EMI) Shielding Effectiveness (SE)

    Science.gov (United States)

    Kessel, Kurt R.

    2014-01-01

    The purpose of this testing is to determine the suitability of trivalent chromium conversion coatings that meet the requirements of MIL-DTL-5541, Type II, for use in applications where high-frequency electrical performance is important. This project will evaluate the ability of coated aluminum to form adequate EMI seals. Testing will assess performance of the trivalent chromium coatings against the known control hexavalent chromium MIL-DTL-5541 Type I Class 3 before and after they have been exposed to a set of environmental conditions. Performance will be assessed by evaluating shielding effectiveness (SE) test data from a variety of test samples comprised of different aluminum types and/or conversion coatings.

  13. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    Energy Technology Data Exchange (ETDEWEB)

    Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

  14. Nano-Ceramic Coated Plastics

    Science.gov (United States)

    Cho, Junghyun

    2013-01-01

    Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (plastics. One possible way of processing nanoceramic coatings at low temperatures (plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

  15. Explosives detection using nanoporous coatings

    Science.gov (United States)

    Pina, María P.; Pellejero, Ismael; Urbiztondo, Miguel; Sesé, Javier; Santamaría, J.

    2011-06-01

    Zeolite-coated cantilevers provided with internal heating elements have been developed and used for the selective detection of nitroderivates, in particular o-nitrotoluene as an example of an explosive-related molecule. In particular, Co exchanged commercial BEA zeolites have been deployed of rectangular Si cantilevers by microdropping technique. In particular, two different strategies have been demonstrated to increase the zeolite modified cantilevers performance: the sensing coating and the operating temperature. As a result, o-nitrotoluene LOD values below 1 ppm are attained at room temperature conditions; whereas the interference of toluene at concentrations below 1000 ppm is completely suppressed by heating the cantilever.

  16. Testing Cadmium-Free Coatings

    Science.gov (United States)

    2011-08-30

    Metallic Platings • Zinc (Zn) • Nickel (Ni) • Zinc Nickel (ZnNi) • Tin Zinc (SnZn) “ Paint -like” Coatings • Zinc-Rich • Magnesium-Rich • Zinc Aluminum-Rich...None of these match all properties of Cd 6 OPSEC approved for public release Fastener Coating Issues Cont’d Siloxane/Polysiloxane  Silicate ...Polymer-based Zirconium-based These passivation chemistries do not match all properties of Cr6+ Either paint adhesion is reduced Or Corrosion protection

  17. Corrosion-resistant coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

  18. Coating of alginate capsules

    OpenAIRE

    Hadjialirezaei, Soosan

    2013-01-01

    Alginate is a popular candidate for encapsulation of cells due to the formation of gels with divalent ions under physiological conditions. Stable alginate gels can be formed by the selection of alginates with a high content of guluronic acid (G) and gelling in a mixture of calcium and barium. These alginate gels have been proposed as immune protective barriers for the transplantation of human pancreatic islets (insulin producing cells) for the treatment of type 1 diabetes where the alginate g...

  19. Thick ceramic coating technique. Atsuniku ceramic coating gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Sata, N. (Government Industrial Reserach Institute, Tohoku, Sendai (Japan))

    1987-10-15

    This paper describes a thick ceramic coating technique that uses a reactive bonding process. This process coats interior of a metallic cylinder or surface of a metal having optional curvature with thick (2 mm to 3 mm) ceramics composed mainly of alumina. The process features easiness in coating and simplicity of the equipment. Reactive heat generated from thermit reaction melts iron and alumina as the reaction products, and produces molten ceramics which is cooled on the metal surface to deposit and solidify as a ceramics layer, thus completing the synthesis and the coating in one process. Its application fields would include reaction tubes, abrasive fluid tubes, and high-temperature fluid tubes that can utilize the ceramics' resistance to abrasion, corrosion and heat as well as heat insulation. The ceramics layer has a hardness of about Hv 1500 and porosity from 2 to 3%. The bonding strength between the substrate metal and the ceramics layer can achieve 10 MPa to 20 MPa as a result of surface oxidation treatment and cooling treatment given initially to prevent the outer wall temperature from rising. 2 figs.

  20. Photocatalytic activity of titanium dioxide nanoparticle coatings applied on autoclaved aerated concrete: effect of weathering on coating physical characteristics and gaseous toluene removal.

    Science.gov (United States)

    Maury-Ramirez, Anibal; Demeestere, Kristof; De Belie, Nele

    2012-04-15

    Autoclaved aerated concrete has been coated by TiO(2) nanoparticles through a dip-coating (DC) and a novel vacuum saturation (VS) method to investigate the weathering resistance and gaseous toluene removal potential of both coating types. The effect of intensive weathering - corresponding to a period of about 25 years - on the coating characteristics was studied in terms of TiO(2) content, coating thickness and color changes. Toluene removal was investigated in a lab-scale flow-through photoreactor at 24°C and 52% relative humidity, and results obtained immediately after application of the coatings and after two weathering stages were compared. Weathering of the DC and VS coated samples resulted into a decrease of the coating layer thickness of more than 98%, confirmed by a decline in TiO(2) content by more than 99% and 93%, respectively. Surprisingly, toluene removal efficiencies before and after weathering kept constant at about 95% for both coating types, corresponding to an elimination rate of 60-70 mg/(m(2)h) at an initial toluene concentration of 15 ppm(v) and a gas residence time of 3 min. Increasing the toluene load by applying higher toluene inlet concentrations (up to 35 ppm(v)) and lower gas residence times (1 min) did decrease the toluene removal efficiency to 32-41%, but elimination rates increased up to 214 mg/(m(2)h), being a factor of 1.6-4.5 times higher than reported in recent work. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. MHD Flow and Heat Transfer Analysis in the Wire Coating Process Using Elastic-Viscous

    Directory of Open Access Journals (Sweden)

    Zeeshan Khan

    2017-01-01

    Full Text Available The most important plastic resins used for wire coating are polyvinyl chloride (PVC, nylon, polysulfone, and low-/high-density polyethylene (LDPE/HDPE. In this article, the coating process is performed using elastic-viscous fluid as a coating material for wire coating in a pressure type coating die. The elastic-viscous fluid is electrically conducted in the presence of an applied magnetic field. The governing non-linear equations are modeled and then solved analytically by utilizing an Adomian decomposition method (ADM. The convergence of the series solution is established. The results are also verified by Optimal Homotopy Asymptotic Method (OHAM. The effect of different emerging parameters such as non-Newtonian parameters α and β, magnetic parameter Mand the Brinkman number Br on solutions (velocity and temperature profiles are discussed through several graphs. Additionally, the current results are compared with published work already available.

  2. Study of Physical Properties of Nano-Silica Coated Cotton Textiles

    Directory of Open Access Journals (Sweden)

    Sidra Saleemi

    2015-04-01

    Full Text Available This research was aimed to investigate the effect of silica sol-gel coating on air permeability, stiffness and tensile properties of dyed cotton fabric. Various concentrations of silica nanoparticles were applied on dyed cotton substrate using two different cross-linkers through sol-gel method. The homogenous sol-gel coating dispersions were prepared by using an ultrasonicator. Coated samples were tested for mechanical and comfort properties such as tensile strength, stiffness, crease recovery and air permeability. It was found that tensile strength and crease recovery of coated substrate were slightly improved. On other hand, it was observed that fabric stiffness and air permeability were affected slightly by increasing concentration of silica nano particle. It was also observed that type of cross-linker has strong influence on coated fabric?s strength and flexural rigidity.

  3. Routes to extrinsic and intrinsic self-healing corrosion protective sol-gel coatings: a review

    Science.gov (United States)

    Abdolah Zadeh, M.; van der Zwaag, S.; Garcia, S. J.

    2013-06-01

    Sol-gel pre-treatments and coatings are an important class of passive protective coatings, which can effectively prevent corrosion of various metallic substrates through adhesion improvement and barrier protection. Recently, sol-gel chemistry has been proposed as an appropriate method for implementation of self-healing functionality in coatings via extrinsic concepts. In this review we will analyze the most relevant existing works on self-healing sol-gel coatings, including new work done in the direction of implementing intrinsic healing capabilities to sol-gels. The development of active sol-gel coatings is due to the broad chemical versatility of precursors and low processing temperature of this type of chemistry.

  4. A shape-recovery polymer coating for the corrosion protection of metallic surfaces.

    Science.gov (United States)

    Lutz, Alexander; van den Berg, Otto; Van Damme, Jonas; Verheyen, Karen; Bauters, Erwin; De Graeve, Iris; Du Prez, Filip E; Terryn, Herman

    2015-01-14

    Self-healing polymer coatings are a type of smart material aimed for advanced corrosion protection of metals. This paper presents the synthesis and characterization of two new UV-cure self-healing coatings based on acrylated polycaprolactone polyurethanes. On a macroscopic scale, the cured films all show outstanding mechanical properties, combining relatively high Young's modulus of up to 270 MPa with a strain at break above 350%. After thermal activation the strained films recover up to 97% of their original length. Optical and electron microscopy reveals the self-healing properties of these coatings on hot dip galvanized steel with scratches and microindentations. The temperature-induced closing of such defects restores the corrosion protection and barrier properties of the coating as shown by electrochemical impedance spectroscopy and scanning vibrating electrode technique. Therefore, such coatings are a complementary option for encapsulation-based autonomous corrosion protection systems.

  5. Evaluation of using edible coating and ripening on Dangke, a traditional cheese of Indonesia

    Directory of Open Access Journals (Sweden)

    Malaka, R.

    2017-03-01

    Full Text Available Dangke is a traditional soft cheese from Enrekang, South Sulawesi Indonesia which is produced through heat denaturation at 85°C and enzymatic coagulation using papaya latex. The quality, microstructure and storage life of the cheese are affected by several factors such as denaturation temperature, enzyme concentration, moulding pressure, coating, and ripening. The objective of this study was to evaluated of using edible coating and ripening on Dangke cheese. The experiment was conducting using factorial design with five replications. The experimental variables were the type of edible coating used (agar, CMC and bee wax and the length of ripening (10, 20 and 30 days. Parameter was measured hardness, microstructure, and sensory evaluation. The overall result indicated that the use of edible coating can extend the shelf life, increase hardness, and more compact microstructure. Sensory evaluation also indicated that the cheese coated with film forming edible materials had had white color, more milk like smell (smelly milk, and smoother texture.

  6. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  7. Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

    Directory of Open Access Journals (Sweden)

    Leticia Esteban-Tejeda

    2014-07-01

    Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

  8. The influence of coating technologies on stress-strain characteristics of the sample at periodic loading

    Science.gov (United States)

    Zakharchenko, K. V.; Zubkov, V. P.; Kapustin, V. I.; Maksimovski, E. A.; Talanin, A. V.

    2017-10-01

    The article is devoted to the research on influence of coating technologies on stress-strain characteristics of a heterogeneous sample (the substrate-coating system) at periodic stress-controlled loading. The comparison of stress-strain characteristics of samples with three types of surface layer showed that the coatings lead to the change in stress at which inelastic phenomena appear in the material. Apart stress-strain characteristics of samples, microrelief on the samples’ surface and formation of a slipband in the grain structure of the coatings were studied in the experiment. It is stated that cold dynamic spraying, which is performed by centrifugal acceleration of particles in vacuum, makes it possible to obtain a coating with better strength and stress-strain characteristics in comparison with cladding.

  9. Functional hydrophobin-coating of thermally hydrocarbonized porous silicon microparticles.

    Science.gov (United States)

    Bimbo, Luis M; Mäkilä, Ermei; Raula, Janne; Laaksonen, Timo; Laaksonen, Päivi; Strommer, Katharina; Kauppinen, Esko I; Salonen, Jarno; Linder, Markus B; Hirvonen, Jouni; Santos, Hélder A

    2011-12-01

    Porous silicon (PSi) particles have been widely used in modulating the dissolution rate of various types of drugs loaded within its mesopores. This material can be surface treated in order to vary its hydrophobicity and several other properties, such as drug loading degree and release rate. Hydrophobins are a family of self-assembling proteins of fungal origin which have the ability to form layers on hydrophobic materials. This type of protein layer can modify the characteristics and control the binding properties of the surface on which it assembles. In this study, we have developed a procedure to coat thermally hydrocarbonized-PSi microparticles with hydrophobin II (HFBII) in order to modify the particles' hydrophobicity and to improve their biocompatibility, while maintaining intact the advantageous drug releasing properties of the PSi. The HFBII content adsorbed onto the particles was successfully quantified by a protein assay. Drug dissolution and permeation across Caco-2 cell monolayers were also conducted, together with viability studies in AGS, Caco-2 and HT-29 cells. The characterization and coating stability assessment showed that the HFBII-coating desorbs partially from the particles' surface as the pH increases. The HFBII coating also improved the biocompatibility of the particles without compromising the enhanced drug permeation or release. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Self-assembling particle-siloxane coatings for superhydrophobic concrete.

    Science.gov (United States)

    Flores-Vivian, Ismael; Hejazi, Vahid; Kozhukhova, Marina I; Nosonovsky, Michael; Sobolev, Konstantin

    2013-12-26

    We report here, for the first time in the literature, a method to synthesize hydrophobic and superhydrophobic concrete. Concrete is normally a hydrophilic material, which significantly reduces the durability of concrete structures and pavements. To synthesize water-repellent concrete, hydrophobic emulsions were fabricated and applied on portland cement mortar tiles. The emulsion was enriched with the polymethyl-hydrogen siloxane oil hydrophobic agent as well as metakaolin (MK) or silica fume (SF) to induce the microroughness and polyvinyl alcohol (PVA) fibers to create hierarchical surfaces. Various emulsion types were investigated by using different mixing procedures, and single- and double-layer hydrophobic coatings were applied. The emulsions and coatings were characterized with optical microscope and scanning electron microscope (SEM), and their wetting properties, including the water contact angle (CA) and roll-off angle, were measured. A theoretical model for coated and non-coated concrete, which can be generalized for other types of materials, was developed to predict the effect of surface roughness and composition on the CA. An optimized distance between the aggregates was found where the CA has the highest value. The maximal CA measured was 156° for the specimen with PVA fibers treated with MK based emulsion. Since water penetration is the main factor leading to concrete deterioration, hydrophobic water-repellent concretes have much longer durability then regular concretes and can have a broad range of applications in civil and materials engineering.

  11. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  12. Aesthetic coatings for Wisconsin bridge components : [brief].

    Science.gov (United States)

    2014-03-01

    Over the past several years, the Wisconsin Department of Transportation (WisDOT) has : experienced performance-related issues with aesthetic and protective coatings used on : Wisconsin bridges. Public agencies make significant investments in coating ...

  13. Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation.

    Science.gov (United States)

    Tapsir, Zafirah; Jamaludin, Farah H; Pingguan-Murphy, Belinda; Saidin, Syafiqah

    2018-02-01

    The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.

  14. Development of silicide coating over molybdenum based refractory alloy and its characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, S.P., E-mail: spc@barc.gov.i [Materials Processing Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Banerjee, S.; Sharma, I.G.; Suri, A.K. [Materials Processing Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2010-08-15

    Molybdenum based refractory alloys are potential candidate materials for structural applications in high temperature compact nuclear reactors and fusion reactors. However, these alloys being highly susceptible to oxidation in air or oxygen at elevated temperature, undergoes severe losses from highly volatile molybdenum trioxide species. Present investigation, therefore, examines the feasibility of development of silicide type of coating over molybdenum base TZM alloy shape (Mo > 99 wt.%) using pack cementation coating technique. TZM alloy was synthesized in this laboratory from oxide intermediates of MoO{sub 2}, TiO{sub 2} and ZrO{sub 2} in presence of requisite amount of carbon, by alumino-thermic reduction smelting technique. The arc melted and homogenized samples of TZM alloy substrate was then embedded in the chosen and intimately mixed pack composition consisting of inert matrix (Al{sub 2}O{sub 3}), coating powder (Si) and activator (NH{sub 4}Cl) taken in the judicious proportion. The sealed charge packs contained in an alumina crucible were heated at temperatures of 1000 {sup o}C for 8-16 h heating cycle to develop the coating. The coating phase was confirmed to be of made of MoSi{sub 2} by XRD analysis. The morphology of the coating was studied by SEM characterization. It had revealed that the coating was diffusion bonded where Si from coating diffused inward and Mo from TZM substrate diffused outward to form the coating. The coating was found to be resistant to oxidation when tested in air up to 1200 {sup o}C. A maximum 100 {mu}m of coating thickness was achieved on each side of the substrate.

  15. Coated woven materials and method of preparation

    Science.gov (United States)

    McCreary, W.J.; Carroll, D.W.

    Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

  16. Thermal barrier coating system having improved adhesion

    Science.gov (United States)

    Bill, R. C.; Sovey, J. S. (Inventor)

    1982-01-01

    The adherence between a ceramic thermal barrier coating and a metal bond coating is improved by ion sputtering a ceramic film on the bond cost. A ceramic thermal barrier coating is then plasma-sprayed onto this primer film. This improves the integrity and strength of the interface between the plasma-sprayed ceramic layer and metallic bond coat which insures stronger adherence between the metal and the ceramic.

  17. Fusion silicide coatings for tantalum alloys.

    Science.gov (United States)

    Warnock, R. V.; Stetson, A. R.

    1972-01-01

    Calculation of the performance of fusion silicide coatings under simulated atmospheric reentry conditions to a maximum temperature of 1810 K (2800 F). Both recently developed and commercially available coatings are included. Data are presented on oxidation rate with and without intentional defecting, the influence of the coatings on the ductile-brittle bend transition temperature, and the mechanical properties. Coatings appear capable of affording protection for at least 100 simulated cycles to 2600 F and 63 cycles to 2800 F.

  18. Growth and morphogenesis of embryonic mouse organs on non-coated and extracellular matrix-coated Biopore membrane

    Science.gov (United States)

    Hardman, P.; Klement, B. J.; Spooner, B. S.

    1993-01-01

    Embryonic mouse salivary glands, pancreata, and kidneys were isolated from embryos of appropriate gestational age by microdissection, and were cultured on Biopore membrane either non-coated or coated with type I collagen or Matrigel. As expected, use of Biopore membrane allowed high quality photomicroscopy of the living organs. In all organs extensive mesenchymal spreading was observed in the presence of type I collagen or Matrigel. However, differences were noted in the effects of extracellular matrix (ECM) coatings on epithelial growth and morphogenesis: salivary glands were minimally affected, pancreas morphogenesis was adversely affected, and kidney growth and branching apparently was enhanced. It is suggested that these differences in behaviour reflect differences in the strength of interactions between the mesenchymal cells and their surrounding endogenous matrix, compared to the exogenous ECM macromolecules. This method will be useful for culture of these and other embryonic organs. In particular, culture of kidney rudiments on ECM-coated Biopore offers a great improvement over previously used methods which do not allow morphogenesis to be followed in vitro.

  19. On air entrainment in coatings.

    Science.gov (United States)

    Simpkins, P G; Kuck, V J

    2003-07-15

    A series of experiments that clarify how air bubbles become entrained into coatings are described. The contact line dynamics at the air-liquid interface surrounding a fiber is characterized for a typical coating die operating under atmospheric and pressurized conditions. Glycerin and other viscous liquids are used to reveal that a critical fiber speed exists at which air entrainment begins. The observations confirm that the critical capillary number Ca(c) depends on the physical properties of the coating material, in the form of the Morton number. When the liquid supply is pressurized, the experiments show that adjusting the pressure can stabilize the displaced free surface interface at a prescribed location. Controlling the meniscus location in this way eliminates air entrainment. The threshold occurs when the applied pressure balances the shear exerted on the coating by the moving fiber. Using this approach it is possible to eliminate air entrainment and attain stable wetting at very large values of the capillary number, e.g., Ca congruent with 50.

  20. Terahertz antireflection coatings using metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hou-tong [Los Alamos National Laboratory; Zhou, Jiangfeng [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Azad, Abul K [Los Alamos National Laboratory; Chen, Frank [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory

    2010-01-01

    We demonstrate terahertz metamaterial antireflection coatings (ARCs) that significantly reduce the reflection and enhance the transmission at an interface of dielectric media. They are able to operate over a wide range of incidence angles for both TM and TE polarizations. Experiments and finite-element simulations will be presented and discussed.

  1. Space stable thermal control coatings

    Science.gov (United States)

    Harada, Y.

    1977-01-01

    Efforts to develop an engineering paint were concentrated on inorganic silicate-bonded systems as opposed to the silicone coatings. The UV-vacuum stability of potassium silicate-Zn2TiO4 paints were shown to be quite good. Reflectance optimization of these systems is being studied by maximizing thickness and pigment to binder ratio.

  2. Moisture transport in coated plaster

    NARCIS (Netherlands)

    Goossens, E.L.J.; Van der Spoel, W.H.; Bancken, E.L.J.

    2001-01-01

    In the framework of the research project: 'Water balance of water-borne paint systems on plaster substrates in relation to fungal growth', a study is carried out to moisture transport mechanisms in coated gypsum plaster. In this contribution, the set-up of the study is described. Besides a

  3. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, N.; Liu, Rongrong; Vancso, Gyula J.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of

  4. Industrial Coatings at Extreme Conditions

    DEFF Research Database (Denmark)

    Subramanian, Srinath; Pérez Hornero, Clara; Pedersen, Lars Thorslund

    With the gradual depletion of oil wells operable at relatively lower temperatures and pressures, the upstream oil industry relies on High Pressure High Temperature (HPHT) wells to source crude oil and gas. HPHT well extraction and processing require anticorrosive coatings applied on substrates...

  5. Insulator coating for high temperature alloys method for producing insulator coating for high temperature alloys

    Science.gov (United States)

    Park, Jong Hee

    1998-01-01

    A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface. Lastly, the invention provides an electrically insulative coating comprising an underlying structural substrate coated with an oxide or nitride compound

  6. Absorptive coating for aluminum solar panels

    Science.gov (United States)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  7. Antireflective Coatings for Glass and Transparent Polymers

    NARCIS (Netherlands)

    Buskens, P.; Burghoorn, M.; Danho Mourad, M.C.; Vroon, Z.

    2016-01-01

    Antireflective coatings (ARCs) are applied to reduce surface reflections. We review coatings that reduce the reflection of the surface of the transparent substrates float glass, polyethylene terephthalate, poly(methyl methacrylate), and polycarbonate. Three main coating concepts exist to lower the

  8. Moisture in organic coatings - a review

    NARCIS (Netherlands)

    Wel, G.K. van der; Adan, O.C.G.

    1999-01-01

    A review is given on transport and equilibrium sorption of moisture in polymer films and organic coatings. Polymeric material forms the continuous phase of a coating and is therefore important for transport properties. Besides polymer, coatings consist of pigments and fillers and various additives,

  9. Applicability of coatings to control metal dusting

    NARCIS (Netherlands)

    Hermse, C.G.M.; Wortel, J.C. van

    2009-01-01

    We have performed a long term comparative study between five wrought and three centricast materials, both as-is, and in coated condition. Two commercially available coatings were applied to each different alloy. One coating was aluminum based with a chromium rich intermediate layer. The other

  10. 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.

  11. Zirconium influence on microstructure of aluminide coatings ...

    Indian Academy of Sciences (India)

    C) are protected by alumina coatings such as nickel aluminide. High temperature coatings based on β-NiAl intermatallic phase are extensively used to protect components against oxidation in gas turbine engines. However, aluminide coatings based on NiAl phase do not fulfil the requirements such as good adhesion of the.

  12. Multispectral Image Analysis for Astaxanthin Coating Classification

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Ersbøll, Bjarne Kjær; Nielsen, Michael Engelbrecht

    2012-01-01

    Industrial quality inspection using image analysis on astaxanthin coating in aquaculture feed pellets is of great importance for automatic production control. The pellets were divided into two groups: one with pellets coated using synthetic astaxanthin in fish oil and the other with pellets coated...

  13. Microstructures, hardness and bioactivity of hydroxyapatite coatings

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-10-01

    Full Text Available 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...

  14. Preparation of Metal Coatings on Steel Balls Using Mechanical Coating Technique and Its Process Analysis

    Directory of Open Access Journals (Sweden)

    Liang Hao

    2017-04-01

    Full Text Available We successfully applied mechanical coating technique to prepare Ti coatings on the substrates of steel balls and stainless steel balls. The prepared samples were analyzed by X-ray diffraction (XRD and scanning electron microscopy (SEM. The weight increase of the ball substrates and the average thickness of Ti coatings were also monitored. The results show that continuous Ti coatings were prepared at different revolution speeds after different durations. Higher revolution speed can accelerate the formation of continuous Ti coatings. Substrate hardness also markedly affected the formation of Ti coatings. Specifically, the substance with lower surface hardness was more suitable as the substrate on which to prepare Ti coatings. The substrate material plays a key role in the formation of Ti coatings. Specifically, Ti coatings formed more easily on metal/alloy balls than ceramic balls. The above conclusion can also be applied to other metal or alloy coatings on metal/alloy and ceramic substrates.

  15. The oxidation behavior of classical thermal barrier coatings exposed to extreme temperature

    Directory of Open Access Journals (Sweden)

    Alina DRAGOMIRESCU

    2017-03-01

    Full Text Available Thermal barrier coatings (TBC are designed to protect metal surfaces from extreme temperatures and improve their resistance to oxidation during service. Currently, the most commonly used systems are those that have the TBC structure bond coat (BC / top coat (TC layers. The top coat layer is a ceramic layer. Oxidation tests are designed to identify the dynamics of the thermally oxide layer (TGO growth at the interface of bond coat / top coat layers, delamination mechanism and the TBC structural changes induced by thermal conditions. This paper is a short study on the evolution of aluminum oxide protective layer along with prolonged exposure to the testing temperature. There have been tested rectangular specimens of metal super alloy with four surfaces coated with a duplex thermal barrier coating system. The specimens were microscopically and EDAX analyzed before and after the tests. In order to determine the oxide type, the samples were analyzed using X-ray diffraction. The results of the investigation are encouraging for future studies. The results show a direct relationship between the development of the oxide layer and long exposure to the test temperature. Future research will focus on changing the testing temperature to compare the results.

  16. A study of strontium doped calcium phosphate coatings on AZ31

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satish S., E-mail: sss42@pitt.edu [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Roy, Abhijit, E-mail: abr20@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun E.; Ohodnicki, John; Loghmanian, Autrine [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Banerjee, Ipsita [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, PA 15261 (United States)

    2014-07-01

    Calcium phosphate (CaP) coatings have been studied to tailor the uncontrolled non-uniform corrosion of Mg based alloys while simultaneously enhancing bioactivity. The use of immersion techniques to deposit CaP coatings is attractive due to the ability of the approach to coat complex structures. In the current study, AZ31 substrates were subjected to various pretreatment conditions prior to depositing Sr{sup 2+} doped and undoped CaP coatings. It was hypothesized that the bioactivity and corrosion protection of CaP coatings could be improved by doping with Sr{sup 2+}. Heat treatment to elevated temperatures resulted in the diffusion of alloying elements, Mg and Zn, into the pretreated layer. Sr{sup 2+} doped and undoped CaP coatings formed on the pretreated substrates consisted of biphasic mixtures of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA). Electrochemical corrosion experiments indicated that the extent of Sr{sup 2+} doping and pretreatment both influenced the corrosion protection. Cytotoxicity was evaluated with MC3T3-E1 mouse preosteoblasts and human mesenchymal stem cells (hMSCs). For both cell types, proliferation decreased upon increasing the Sr{sup 2+} concentration. However, both osteogenic gene and protein expression significantly increased upon increasing Sr{sup 2+} concentration. These results suggest that Sr{sup 2+} doped coatings are capable of promoting osteogenic differentiation on degradable Mg alloys, while also enhancing corrosion protection, in comparison to undoped CaP coatings.

  17. Initial bacterial deposition on bare and zeolite-coated aluminum alloy and stainless steel.

    Science.gov (United States)

    Chen, Gexin; Beving, Derek E; Bedi, Rajwant S; Yan, Yushan S; Walker, Sharon L

    2009-02-03

    In this study, the impact of zeolite thin film coatings on bacterial deposition and "biofouling" of surfaces has been investigated in an aqueous environment. The synthesis of two types of zeolite coatings, ZSM-5 coated on aluminum alloy and zeolite A coated on stainless steel, and the characterization of the coated and bare metal surfaces are described. The extent of cell deposition onto the bare and zeolite-coated aluminum alloy and stainless steel surfaces is investigated in a parallel plate flow chamber system under a laminar flow conditions. The initial rates of bacterial transfer to the various surfaces are compared by utilizing a marine bacterium, Halomonas pacifica g, under a range of ionic strength conditions. H. pacifica g deposited onto bare metal surfaces to a greater extent as compared with cells deposited onto the zeolite coatings. The surface properties found to have the most notable effect on attachment are the electrokinetic and hydrophobicity properties of the metal and zeolite-coated surfaces. These results suggest that a combination of two chemical mechanisms-hydrophobic and electrostatic interactions-contribute to the antifouling nature of the zeolite surface. Additional observations on the relative role of the hydrodynamic and physical phenomena are also discussed.

  18. THE USE OF COATINGS FOR HOT CORROSION AND EROSION PROTECTION IN TURBINE HOT SECTION COMPONENTS

    Directory of Open Access Journals (Sweden)

    Hayrettin AHLATCI

    1999-01-01

    Full Text Available High pressure turbine components are subjected to a wide variety of thermal and mechanical loading during service. In addition, the components are exposed to a highly oxidizing atmosphere which may contain contaminants such as sulphates, chlorides and sulphuorous gases along with erosive media. So the variety of surface coatings and deposition processes available for the protection of blade and vane components in gas turbines are summarised in this study. Coating types range from simple diffusion aluminides to modified aluminides and a CoCrAlY overlayer. The recommendations for corrosion-resistant coatings (for low temperature and high temperature hot corrosion environments are as follows: silicon aluminide and platinumchromium aluminide for different gas turbine section superalloys substrates. Platinum metal additions are used to improve the properties of coatings on turbine components. Inorganic coatings based on ceramic films which contain aluminium or aluminium and silicon are very effective in engines and gas turbines. Diffusion, overlayer and thermal barrier coatings which are deposited on superalloys gas turbine components by pack cementation, plasma spraying processes and a number of chemical vapour deposition, physical vapour deposition processes (such as electron beam, sputtering, ion plating are described. The principles underlying the development of protective coatings serve as a useful guide in the choice of coatings for other high temperature applications.

  19. Emerging technologies for long-term antimicrobial device coatings: advantages and limitations.

    Science.gov (United States)

    Cyphert, Erika L; von Recum, Horst A

    2017-04-01

    Over the past 20 years, the field of antimicrobial medical device coatings has expanded nearly 30-fold with technologies shifting their focus from diffusion-only based (short-term antimicrobial eluting) coatings to long-term antimicrobial eluting and intrinsically antimicrobial functioning materials. A variety of emergent coatings have been developed with the goal of achieving long-term antimicrobial activity in order to mitigate the risk of implanted device failure. Specifically, the coatings can be grouped into two categories: those that use antibiotics in conjunction with a polymer coating and those that rely on the intrinsic properties of the material to kill or repel bacteria that come into contact with the surface. This review covers both long-term drug-eluting and non-eluting coatings and evaluates the inherent advantages and disadvantages of each type while providing an overview of variety applications that the coatings have been utilized in. Impact statement This work provides an overview, with advantages and limitations of the most recently developed antibacterial coating technologies, enabling other researchers in the field to more easily determine which technology is most advantageous for them to further develop and pursue.

  20. Biomimetic scaffolds containing nanofibers coated with willemite nanoparticles for improvement of stem cell osteogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanifard, Rouhallah [Department of Biotechnology, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Seyedjafari, Ehsan, E-mail: seyedjafari@ut.ac.ir [Department of Biotechnology, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Ardeshirylajimi, Abdolreza [Department of Stem Cell Biology, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); Soleimani, Masoud [Department of Hematology, Faculty of Medical Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2016-05-01

    Nowadays, discovering osteogenesis stimulating effectors is one of the major topics in bone tissue engineering and regenerative medicine. In this study, the proliferation rate and osteogenic differentiation potency of adipose-derived mesenchymal stem cells (AT-MSCs) cultured on poly (L-lactide acid) (PLLA) and willemite-coated PLLA were investigated by MTT assay and common osteogenic markers such as alkaline phosphatase (ALP) activity, calcium mineral deposition and bone-related genes expression. Willemite-coated PLLA showed a higher proliferation support to AT-MSCs in comparison to PLLA and TCPS. During the period of study, AT-MSCs cultured on willemite-coated PLLA scaffolds exhibited the greatest ALP activity and mineralization. Gene expression analysis demonstrated that the highest expression of four important osteogenic-related genes, osteonectin, Runx2, collagen type 1 and osteocalcin was observed in stem cells cultured on willemite-coated PLLA nanofibrous scaffolds. According to the results, willemite-coated PLLA could be a suitable substrate to support the proliferation and osteogenic differentiation of stem cells and holds promising potential for bone tissue engineering and regenerative medicine applications. - Highlights: • Biodegradable PLLA eletrospun nanofibrous scaffold was prepared. • PLLA nanofibers were treated with plasma and coated with willemite nanoparticles. • MSC on willemite-coated PLLA showed greater osteogenic differentiation than those on uncoated PLLA and TCPS. • Willemite-coated nanofibers hold promising potential for bone tissue engineering application.