WorldWideScience

Sample records for arc deposition technology

  1. Amorphous boron coatings produced with vacuum arc deposition technology

    Science.gov (United States)

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

    2002-05-01

    In principle, boron (B) as a material has many excellent surface properties, including corrosion resistance, very high hardness, refractory properties, and a strong tendency to bond with most substrates. The potential technological benefits of the material have not been realized, because it is difficult to deposit it as coatings. B is difficult to evaporate, does not sputter well, and cannot be thermally sprayed. In this article, first successful deposition results from a robust system, based on the vacuum (cathodic) arc technology, are reported. Adherent coatings have been produced on 1100 Al, CP-Ti, Ti-6Al-4V, 316 SS, hard chrome plate, and 52 100 steel. Composition and thickness analyses have been performed by Rutherford backscattering spectroscopy. Hardness (H) and modules (E) have been evaluated by nanoindentation. The coatings are very pure and have properties characteristic of B suboxides. A microhardness of up to 27 GPa has been measured on a 400-nm-thick film deposited on 52 100 steel, with a corresponding modulus of 180 GPa. This gives a very high value for the H/E ratio, a figure-of-merit for impact resistance of the film. A number of applications are contemplated, including corrosion/abrasion protection for die-casting dies and improved wear resistance for biomedical implants.

  2. Amorphous boron coatings produced with vacuum arc deposition technology

    CERN Document Server

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

    2002-01-01

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

  3. Review of cathodic arc deposition technology at the start of the new millennium

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, D M; Anders, A

    2000-02-24

    The vacuum cathodic arc has been known to provide a means of producing coatings since the second half of the 19th century. This makes it one of the oldest known means for making coatings in a vacuum. In the last century it has been recognized that the copious quantities of ions produced by the process offers certain advantages in terms of coating properties. Specifically, ions can be steered and/or accelerated toward the parts to be coated. This, in turn, can provide enhanced adhesion, film density, and composition stoichiometry in the case of compound coatings. The ions generated by the cathodic arc have high ''natural'' kinetic energy values in the range 20-200 eV, leading to enhanced surface mobility during the deposition process and even ion subplantation. In many cases, dense coatings are achieved even when non-normal arrival angles are involved. The ion energy can further manipulated by the plasma immersion biasing technique. The issue of macroparticle contamination has been addressed by a variety of novel plasma filters. In spite of all of these advantages, this deposition technique has not been widely adopted in the western nations for commercial coating except in the case of enhancing the performance of cutting tools. The purpose of the this review is to explore reasons for this lack of general use of the technology and to point out some encouraging recent developments which may lead to its accelerated adoption for a much wider variety of applications in the near future.

  4. Plasma distribution of cathodic ARC deposition system

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S.; Raoux, S.; Krishnan, K.; MacGill, R.A.; Brown, I.G. [Lawrence Berkeley National Lab., CA (United States)

    1996-08-01

    The plasma distribution using a cathodic arc plasma source with and without magnetic macroparticle filter has been determined by depositing on a transparent plastic substrate and measuring the film absorption. It was found that the width of the distribution depends on the arc current, and it also depends on the cathode material which leads to a spatial separation of the elements when an alloy cathode is used. By applying a magnetic multicusp field near the exit of the magnetic filter, it was possible to modify the plasma distribution and obtain a flat plasma profile with a constant and homogeneous elemental distribution.

  5. PyroArc novel Waste-to-energy technology

    International Nuclear Information System (INIS)

    There is a growing interest in using solid waste as a raw material in the production of gas and materials. A new proprietary technology - called PyroArc - utilizes a wide range of waste fractions combined with a reduction of almost the entire volume. The process employs high temperature plasma technology developed by ScanArc. The Norwegian based enterprise, EnviroArc Technologies AS, has the exclusive rights to use PyroArc technology. (author)

  6. Thermionic vacuum arc - a novel advanced technology for surface coating

    International Nuclear Information System (INIS)

    In this paper a new technology for high quality thin film deposition is presented. The film is condensing on the sample from the plasma state of the vapor phase of the anode material, generated by a Thermionic Vacuum Arc. This process is taking place in a vacuumated vessel at pressures less than 10-5 torr. The thin film is bombarded during its deposition by energetic ions from the plasma of anode material The value of the directed energy of the ions can be established at will in the range of 10 eV up to 500 eV. Due to the above mentioned conditions, the obtained thin films are very smooth. nanostructured, of high purity have a good adherence to the substrates, etc.Because of the high energy level which can be used by Thermionic Vacuum Arc.,this new coating technology is especially convenient for high melting point materials thin film deposition. One of the most convenient field of application of TVA thin film deposition technique, is the nanostructured carbon thin films generation. In fact, due to the high variety of the obtained structures of the carbon (not mentioning the huge number of applications) we are encountering a new field of science. Results on nanostructured thin films obtained using TVA technology is presented

  7. FUNDAMENTAL PROBLEMS IN PULSED-BIAS ARC DEPOSITION

    Institute of Scientific and Technical Information of China (English)

    G.Q.Lin; Z.F.Ding; D.Qi; N.H.Wang; M.D.Huang; D.Z.Wang; Y.N.Wang; C.Dong; L.S.Wen

    2002-01-01

    Arc deposition, a widely used surface coating technique, has disadvantages such aslarge droplet size and high deposition temperature. Recent trend in its renovation isthe introduction of pulsed bias at the substrate. The present paper attempts to describethe deposition process of TiN films using this technique with emphasis laid on theunderstanding of the basic problems such as discharge plasma properties, temperaturecalculation, and droplet size reduction. We show that this technique improves thefilm microstructure and quality, lowers deposition temperature, and allows coatingson insulating substrates. After analyzing load current oscillation behaviors, we havedetermined that the plasma load is of capacitance nature due to plasma sheath and thatit is equivalent to a circuit element consisting of parallel capacitance and resistance.At last, we point out the remaining problems and future development of the pulsed-biasarc deposition technique.

  8. Danarc technology for electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, P.; Gensini, G.; Mavridis [Danieli Centro Met, Buttrio (Italy)

    1995-06-01

    Danarc electric arc furnace technology combines high-impedance technology with bottom tuyeres for oxygen and carbon injection. Together with lance injection and wall burners for both conventional operation and post-combustion, the concept provides full flexibility in the choice of energy sources. The basic philosophy of the concept is to have efficient systems for the supply of both electrical and alternative energy. Operational results from a Danarc furnace at Ferriere Nord show that it is possible to inject high specific amounts of oxygen and carbon as a substitute for electrical energy. The electrical power supply with a fixed or saturable reactor is beneficial because of the high voltage and low current operation. High-impedance operation results in low electrode consumption, reduced electrical losses and a reduction of the supply network disturbance, ie, flicker.

  9. Impedance analysis of nano thickness layered AlGaN acoustic sensor deposited by thermionic vacuum arc

    Science.gov (United States)

    Özen, Soner; Bilgiç, Eyüp; Gülmez, Gülay; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan; Mohammadigharehbagh, Reza

    2016-03-01

    In this study, AlGaN acoustic sensor was deposited on aluminum metal substrate by thermionic vacuum arc (TVA) method for the first time. Gallium materials are used in many applications for optoelectronic device and semiconductor technology. Thermionic vacuum arc is the deposition technology for the variously materials and applications field. The thickness of the acoustic sensor is in deposited as nano layer. Impedance analyses were realized. Also, TVA production parameters and some properties of the deposited layers were investigated. TVA is a fast deposition technology for the gallium compounds and doped gallium compounds. Obtained results show that AlGaN materials are very promising materials. Moreover, these acoustic sensors have been produced by TVA technology.

  10. Complex technology of vacuum-arc processing of structural material surface

    Science.gov (United States)

    Arustamov, V. N.; Ashurov, Kh. B.; Kadyrov, Kh. Kh.; Khudoikulov, I. Kh.

    2015-08-01

    The development of environmentally friendly and energy-resource-saving technologies based on vacuum arc discharge is a topical problem in science and engineering. In view of their unique properties, cathode spots of a vacuum arc induce cleaning of the surface of an article (cathode) from various contaminations and pulsed thermal action on the surface layers. These processes occur in complex with vacuum-arc deposition of coatings in the same technological cycle, which makes it possible to considerably increase the efficiency of methods for changing physical, mechanical, and chemical properties of the surface of steel articles, which considerably increase their service life. Analysis of the formation of the temperature regime of the surface during vacuum arc action and of the parameters of the deposited coating will make it possible to optimize the regimes of complex treatment of the surfaces of articles and is of considerable theoretical and practical importance.

  11. New developments in electric arc furnace technologies

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, P. [Danieli Centrome, France (France)

    1997-04-01

    Technologies are described for the flexible operation of electric arc furnaces combining various energy sources and for the improvement of the electrical behaviour of the furnace. The main part of the article deals with the post-combustion process, as a means of reducing the energy consumption and increasing the furnace productivity. The energy yield from post-combustion is evaluated and compared to operational results. Oxidizing reactions as energy source are discussed. The energy yield for post-combustion is evaluated with data from four furnaces in operation. The energy yield from post-combustion ranges from 4 to 2 kWh per Nm{sup 3} of oxygen representing a range of 4 to 18 Nm{sup 3} oxygen injected for post-combustion. (author) 2 refs.

  12. Research on the use of UHV arc discharges for deposition of superconducting layers

    International Nuclear Information System (INIS)

    High-field superconducting cavities, as used in charged particle accelerators, are at present based mostly on the Nb-bulk technology, but Nb-coated Cu-cavities might offer several advantages. In order to study possibilities of the vacuum arc technique to form high-quality superconducting thin films for the coating RF copper cavities, special efforts have been undertaken within a framework of the scientific collaboration between the 'Tor Vergata' University of Rome and the Andrzej Soltan Institute for Nuclear Studies at Swierk. During recent years several experimental arc-based devices have been designed and constructed in the both research centers. In particular, cathodic-arc sources with planar- and cylindrical-cathodes made of pure Nb have been constructed and investigated. Arc discharges with magnetic filters (for the elimination of micro-droplets) have also been investigated. All these systems have been exploited under ultra-high vacuum (UHV) conditions. The paper describes the status of research on the deposition of superconducting Nb-films, and particularly the recent progress in these investigations. It has been shown that high-quality Nb-films can be deposited with the described UHV arc technique. The critical temperature of film samples, which were coated in planar geometry, is very close to the Nb-bulk value. The very narrow transitions as well as X-ray diffraction patterns indicate that the obtained films are less stressed and more homogeneous than standard ones produced by means of the sputtering technique. The deposited Nb-films have higher RRR (up to 80) and larger grain sizes in a comparison with sputtered ones, which were deposited at the same temperature. The RF measurements have also demonstrated good RF properties of the produced Nb-films. (author)

  13. Automatic arc discharge technology for inscribing long period fiber gratings.

    Science.gov (United States)

    Yin, Guolu; Tang, Jian; Liao, Changrui; Wang, Yiping

    2016-05-10

    We experimentally demonstrate an automatic arc discharge technology for inscribing high-quality long period fiber gratings (LPFGs) with greatly improved inscription efficiency for single mode fiber (SMF) and photonic crystal fiber (PCF). The proposed technology was developed by implementing an embedded program in a commercial fusion splicer. In addition, the improved technology employs an ultraprecision motorized translation stage, and the tensioning mass required by conventional technology was eliminated. While hundreds of arc discharges are generally required by conventional technology, only 30 and 60 arc discharges were required to inscribe LPFGs with dip attenuations of 30 and 20 dB for SMF and PCF, respectively. PMID:27168306

  14. AlN thin films prepared by DC arc deposition

    Science.gov (United States)

    Liang, Hai-feng; Yan, Yi-xin; Miao, Shu-fan

    2006-02-01

    Many researchers are interested in AlN films because of their novel thermal, chemical, mechanical, acoustic, and optical properties. Many methodsincluding such as DC/RF sputtering, chemical vapor deposition (CVD), laser chemical vapor deposition(LCVD), molecular beam epitaxy (MBE), thermal vapor deposition, can be used to prepare AlN films. In this paper, a new method, DC arc deposition, is used to deposite AlN films. It is an anti-reflective, protective film on optical elements. FTIR are used to determine the ALN structure and measure the transmittance spectrum. Ellipsometry is used to determine the films' refractive index, extinction index and thickness. The films' anti-wear properties are tested by pin-on-disc way and the anti-corrosion(anti-acid, anti-alkali, anti-salt) properties are also tested. The results show that the films is AlN films by the 670cm -1 typical peak, the films' extinction index is near to zero in the range of visible and infrared waveband, the films' refractive index is varied from 1.7 to 2.1 at range of visible and infrared waveband. The films have better anti-wear, anti-acid and anti-alkali properties, but their anti-salt properties are not good.

  15. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    International Nuclear Information System (INIS)

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the stopping and range of ions in matter code. We find film contamination of the order of 10-4-10-3, and the memory of the prior history of the deposition hardware can be relatively long lasting

  16. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    International Nuclear Information System (INIS)

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting

  17. Contamination due to memory effects in filtered vacuum arc plasma deposition systems

    CERN Document Server

    Martins, D R; Verdonck, P; Brown, I G

    2002-01-01

    Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

  18. Modeling of thermal plasma arc technology FY 1994 report

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, G.L.; Nguyen, H.D.; Paik, S.; McKellar, M.G.

    1995-03-01

    The thermal plasma arc process is under consideration to thermally treat hazardous and radioactive waste. A computer model for the thermal plasma arc technology was designed as a tool to aid in the development and use of the plasma arc-Joule beating process. The value of this computer model is to: (a) aid in understanding the plasma arc-Joule beating process as applied to buried waste or exhumed buried waste, (b) help design melter geometry and electrode configuration, (c) calculate the process capability of vitrifying waste (i.e., tons/hour), (d) develop efficient plasma and melter operating conditions to optimize the process and/or reduce safety hazards, (e) calculate chemical reactions during treatment of waste to track chemical composition of off-gas products, and composition of final vitrified waste form and (f) help compare the designs of different plasma-arc facilities. A steady-state model of a two-dimensional axisymmetric transferred plasma arc has been developed and validated. A parametric analysis was performed that studied the effects of arc length, plasma gas composition, and input power on the temperatures and velocity profiles of the slag and plasma gas. A two-dimensional transient thermo-fluid model of the US Bureau of Mines plasma arc melter has been developed. This model includes the growth of a slag pool. The thermo-fluid model is used to predict the temperature and pressure fields within a plasma arc furnace. An analysis was performed to determine the effects of a molten metal pool on the temperature, velocity, and voltage fields within the slag. A robust and accurate model for the chemical equilibrium calculations has been selected to determine chemical composition of final waste form and off-gas based on the temperatures and pressures within the plasma-arc furnace. A chemical database has been selected. The database is based on the materials to be processed in the plasma arc furnaces.

  19. Modeling of thermal plasma arc technology FY 1994 report

    International Nuclear Information System (INIS)

    The thermal plasma arc process is under consideration to thermally treat hazardous and radioactive waste. A computer model for the thermal plasma arc technology was designed as a tool to aid in the development and use of the plasma arc-Joule beating process. The value of this computer model is to: (a) aid in understanding the plasma arc-Joule beating process as applied to buried waste or exhumed buried waste, (b) help design melter geometry and electrode configuration, (c) calculate the process capability of vitrifying waste (i.e., tons/hour), (d) develop efficient plasma and melter operating conditions to optimize the process and/or reduce safety hazards, (e) calculate chemical reactions during treatment of waste to track chemical composition of off-gas products, and composition of final vitrified waste form and (f) help compare the designs of different plasma-arc facilities. A steady-state model of a two-dimensional axisymmetric transferred plasma arc has been developed and validated. A parametric analysis was performed that studied the effects of arc length, plasma gas composition, and input power on the temperatures and velocity profiles of the slag and plasma gas. A two-dimensional transient thermo-fluid model of the US Bureau of Mines plasma arc melter has been developed. This model includes the growth of a slag pool. The thermo-fluid model is used to predict the temperature and pressure fields within a plasma arc furnace. An analysis was performed to determine the effects of a molten metal pool on the temperature, velocity, and voltage fields within the slag. A robust and accurate model for the chemical equilibrium calculations has been selected to determine chemical composition of final waste form and off-gas based on the temperatures and pressures within the plasma-arc furnace. A chemical database has been selected. The database is based on the materials to be processed in the plasma arc furnaces

  20. Influences of arc current on composition and properties of MgO thin films prepared by cathodic vacuum arc deposition

    International Nuclear Information System (INIS)

    MgO thin films with high optical transmittances (more than 90%) were prepared by cathodic vacuum arc deposition technique. With the increase of arc current from 40 to 80 A, the deposition pressure decreases and the film thickness increases; the atomic ratio of Mg/O in MgO thin films (obtained by RBS) increases from 0.97 to 1.17, giving that deposited at 50 A most close to the stoichiometric composition of the bulk MgO; the grains of MgO thin films grow gradually as shown in SEM images. XRD patterns show that MgO (1 1 0) orientation is predominant for films prepared at the arc currents ranged from 50 to 70 A. The MgO (1 0 0) orientation is much enhanced and comparable to that of MgO (1 1 0) for films prepared at the arc current of 80 A. The secondary electron emission coefficient of MgO thin film increases with arc current ranged from 50 to 70 A.

  1. Protective coating of inner surface of steel tubes via vacuum arc deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maile, K.; Roos, E.; Lyutovich, A.; Boese, J.; Itskov, M. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA); Ashurov, Kh.; Mirkarimov, A.; Kazantsev, S.; Kadirov, Kh. [Uzbek Academy of Science, Tashkent (Uzbekistan). Arifov Inst. of Electronics

    2010-07-01

    The Vacuum Arc Deposition (VAD) technique based on sputtering a chosen electrode material and its deposition via plasma allows highly-productive technology for creating a wide class of protecting coatings on complex structures. In this work, VAD was applied as a method for the protection of the inner surface of tubes for power-plant boilers against steam oxidation. For this aim, a source cathode of an alloy with high chromium and nickel content was employed in two different VAD treatment systems: a horizontal vacuum chamber (MPA) and a vertical system where the work-piece of the tubes to be protected served as a vacuum changer (Arifov Institute of Electronics). Surface coating with variation of deposition parameters and layer thickness was performed. Characterisation of coated tubes has shown that the method realised in this work allows attainment of material transfer from the cathode to the inner surface with nearly equal chemical composition. It was demonstrated that the initial martensitic structure of the tubes was kept after the vacuum-arc treatment which can provide for both the high mechanical robustness and the corrosion-resistance of the final material. (orig.)

  2. Clinical utility of RapidArcTM radiotherapy technology

    Directory of Open Access Journals (Sweden)

    Infusino E

    2015-11-01

    Full Text Available Erminia Infusino Department of Radiotherapy, Campus Bio-Medico University Hospital, Rome, Italy Abstract: RapidArcTM is a radiation technique that delivers highly conformal dose distributions through the complete rotation (360° and speed variation of the linear accelerator gantry. This technique, called volumetric modulated arc therapy (VMAT, compared with conventional radiotherapy techniques, can achieve high-target volume coverage and sparing damage to normal tissues. RapidArc delivers precise dose distribution and conformity similar to or greater than intensity-modulated radiation therapy in a short time, generally a few minutes, to which image-guided radiation therapy is added. RapidArc has become a currently used technology in many centers, which use RapidArc technology to treat a large number of patients. Large and small hospitals use it to treat the most challenging cases, but more and more frequently for the most common cancers. The clinical use of RapidArc and VMAT technology is constantly growing. At present, a limited number of clinical data are published, mostly concerning planning and feasibility studies. Clinical outcome data are increasing for a few tumor sites, even if only a little. The purpose of this work is to discuss the current status of VMAT techniques in clinical use through a review of the published data of planning systems and clinical outcomes in several tumor sites. The study consisted of a systematic review based on analysis of manuscripts retrieved from the PubMed, BioMed Central, and Scopus databases by searching for the keywords "RapidArc", "Volumetric modulated arc radiotherapy", and "Intensity-modulated radiotherapy". Keywords: IMRT, VMAT, SBRT, SRS, treatment planning software 

  3. Concept for lightweight spaced-based deposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Fulton, Michael; Anders, Andre

    2006-02-28

    In this contribution we will describe a technology path to very high quality coatings fabricated in the vacuum of space. To accomplish the ambitious goals set out in NASA's Lunar-Mars proposal, advanced thin-film deposition technology will be required. The ability to deposit thin-film coatings in the vacuum of lunar-space could be extremely valuable for executing this new space mission. Developing lightweight space-based deposition technology (goal:<300 g, including power supply) will enable the future fabrication and repair of flexible large-area space antennae and fixed telescope mirrors for lunar-station observatories. Filtered Cathodic Arc (FCA) is a proven terrestrial energetic thin-film deposition technology that does not need any processing gas but is well suited for ultra-high vacuum operation. Recently, miniaturized cathodic arcs have already been developed and considered for space propulsion. It is proposed to combine miniaturized pulsed FCA technology and robotics to create a robust, enabling space-based deposition system for the fabrication, improvement, and repair of thin films, especially of silver and aluminum, on telescope mirrors and eventually on large area flexible substrates. Using miniature power supplies with inductive storage, the typical low-voltage supply systems used in space are adequate. It is shown that high-value, small area coatings are within the reach of existing technology, while medium and large area coatings are challenging in terms of lightweight technology and economics.

  4. Microstructural Evolution and Mechanical Properties of Inconel 625 Alloy during Pulsed Plasma Arc Deposition Process

    Institute of Scientific and Technical Information of China (English)

    Fujia Xu; Yaohui Lv; Yuxin Liu; Fengyuan Shu; Peng He; Binshi Xu

    2013-01-01

    Pulsed plasma arc deposition (PPAD),which combines pulsed plasma cladding with rapid prototyping,is a promising technology for manufacturing near net shape components due to its superiority in cost and convenience of processing.In the present research,PPAD was successfully used to fabricate the Ni-based superalloy Inconel 625 components.The microstructures and mechanical properties of deposits were investigated by scanning electron microscopy (SEM),optical microscopy (OM),transmission electron microscopy (TEM) with energy dispersive spectrometer (EDS),microhardness and tensile testers.It was found that the as-deposited structure exhibited homogenous columnar dendrite structure,which grew epitaxially along the deposition direction.Moreover,some intermetallic phases such as Laves phase,minor MC (NbC,TiC) carbides and needle-like δ-Ni3Nb were observed in γ-Ni matrix.Precipitation mechanism and distribution characteristics of these intermetallic phases in the as-deposited 625 alloy sample were analyzed.In order to evaluate the mechanical properties of the deposits,microhardness was measured at various location (including transverse plane and longitudinal plane).The results revealed hardness was in the range of 260-285 HVo.2.In particular,microhardness at the interface region between two adjacent deposited layers was slightly higher than that at other regions due to highly refined structure and the disperse distribution of Laves particles.Finally,the influence of precipitation phases and fabrication strategies on the tensile properties of the as-deposited samples was investigated.The failure modes of the tensile specimens were analyzed with fractography.

  5. A New Waste Disposal Technology-plasma arc Pyrolysis System

    Institute of Scientific and Technical Information of China (English)

    黄建军; 施嘉标; 梁荣庆; 刘正之

    2003-01-01

    This paper introduces a new waste disposal technology with plasma arc. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled pyrolysis-thermal destruction and recovery process. It has four advantages, they are completely safe, clean, high-energy synthesis gas, non-toxic vitrified slag and metal.

  6. Graphite electrode DC arc furnace. Innovative technology summary report

    International Nuclear Information System (INIS)

    The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of

  7. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated as one of the enabling technologies for advanced energy systems. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that promises an order of magnitude increase in deposition rates and achievable coating thicknesses. Since this regime borders on and exceeds the normal operating limits of existing ESD electronic equipment, development is in progress to produce equipment that can consistently and reliably achieve these conditions for a broad range of materials. Progress so far has resulted in a consistent 500% increase in deposition rates, and greater rates still are anticipated. Technology transfer activities are a significant portion of the ESD program effort. Notable successes now include the start-up of a new business to commercialize the ESD technology, the incorporation of the process into the operations of a major gas turbine manufacturer, major new applications in gas turbine blade and steam turbine blade protection and repair, and in military, medical, metal-working, and recreational equipment applications.

  8. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  9. Graphite electrode DC arc technology program for buried waste treatment

    International Nuclear Information System (INIS)

    The goal of the program is to apply EPI's Arc Furnace to the processing of Subsurface Disposal Area (SDA) waste from Idaho National Engineering Laboratory. This is being facilitated through the Department of Energy's Buried Waste Integrated Demonstration (BWID) program. A second objective is to apply the diagnostics capability of MIT's Plasma Fusion Center to the understanding of the high temperature processes taking place in the furnace. This diagnostics technology has promise for being applicable in other thermal treatment processes. The program has two parts, a test series in an engineering-scale DC arc furnace which was conducted in an EPI furnace installed at the Plasma Fusion Center and a pilot-scale unit which is under construction at MIT. This pilot-scale furnace will be capable of operating in a continuous feed and continuous tap mode. Included in this work is the development and implementation of diagnostics to evaluate high temperature processes such as DC arc technology. This technology can be used as an effective stabilization process for Superfund wastes

  10. Deposition of various metal, ceramic, and cermet coatings by an industrial-scale large area filtered arc deposition process

    International Nuclear Information System (INIS)

    Nearly defect-free nitride, carbide, and oxiceramic coatings have been deposited by a unidirectional dual large area filtered arc deposition (LAFAD) process. One LAFAD dual arc vapor plasma source was used in both gas ionization and coating deposition modes with and without vertical magnetic rastering of the plasma flow. Substrates made of different metal alloys, as well as carbide and ceramics, were installed at different vertical positions on the 0.5 m diameter turntable of the industrial-scale batch coating system which was rotated at 12 rpm to assess deposition rates and coating thickness uniformity. Targets of the same or different compositions were installed on the primary cathodic arc sources of the LAFAD plasma source to deposit a variety of coating compositions by mixing the metal vapor and reactive gaseous components in a magnetically confined, strongly ionized plasma flow with large kinetic energy. The maximum deposition rate typically ranged from 1.5 μm/h for TiCr/TiCrN to 2.5 μm/h for Ti/TiN multilayer and AlN single layer coatings, and up to 6 μm/h for AlCr-based oxiceramic coatings for primary cathode current ranging from 120 to 140 A. When the arc current was increased to 200 A, the deposition rates of TiN-based coatings were as high as 5 μm/h. The vertical coating thickness uniformity was ±15% inside of a 150 mm area without vertical rastering. Vertical rastering increased the uniform coating deposition area up to 250 mm. The coating thickness distribution was well correlated with the output ion current distribution as measured by a multisection ion collector probe. Coatings were characterized for thickness, surface profile, adhesion, hardness, and elemental composition. Estimates of electrical resistivity indicated good dielectric properties for most of the TiCrAlY-based oxiceramic, oxinitride, and nitride coatings. The multielement LAFAD plasma flow consisting of fully ionized metal vapor with a reactive gas ionization rate in excess of 50

  11. Influence of Oxygen Pressure on Filtered Vacuum Arc Deposition of Tin Oxide Thin Films

    International Nuclear Information System (INIS)

    Tin oxide is a conducting material which is transparent in the visible region, reflective in the infra-red, and absorbing in the ultraviolet. Applied as a thin film, it is used for transparent electrodes for solar cells and in energy conserving coatings on architectural glass. This paper presents the results of experiments in which tin oxide films were deposited using filtered vacuum arc deposition. A plasma jet of ionized Sn vapor was produced by cathode spots on a 93 mm diameter Sn cathode by a 160 A d.c. arc. The plasma jet was directed through a quarter torus duct using a magnetic field, while droplets of liquid Sn collided with the duct walls and were thus filtered from the plasma stream. The plasma jet was directed either to a probe or to a substrate placed downstream from the duct outlet, and where an oxygen atmosphere was maintained at a pressure P 0-6 mTorr. Arc voltage, ion current, coating transmission and coating conductivity were measured as a function of the oxygen pressure. It was found that the arc voltage was 30V, and relatively independent of p for P<4 mTorr. With higher pressures, the arc increasingly operated in a high voltage mode, with an arc voltage typically 10 V higher than in the low voltage mode. The change from the low to the high voltage mode is likewise associated with a trebling in the extracted ion current, from 250 to 750 mA. The deposition rate decreased linearly from 14 to 5 nm/s when the pressure was increased from 3 to 5 mTorr. The optical extinction length had a maximum value of 2.6 m in the pressure range of 3.9-4.3 mTorr, while minimum electrical conductivities of 410-3 - cm were obtained for 3.8-4.1 mTorr

  12. Metal-doped diamond-like carbon films synthesized by filter-arc deposition

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp3/sp2 bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp3 bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films

  13. Technology development of adjustable grazing incidence x-ray optics for sub-arc second imaging

    Science.gov (United States)

    Reid, P. B.; Aldcroft, T. L.; Cotroneo, V.; Davis, W.; Johnson-Wilke, R. L.; McMuldroch, S.; Ramsey, B. D.; Schwartz, D. A.; Trolier-McKinstry, S.; Vikhlinin, A.; Wilke, R. H. T.

    2012-09-01

    We report on technical progress made over the past year developing thin film piezoelectric adjustable grazing incidence optics. We believe such mirror technology represents a solution to the problem of developing lightweight, sub-arc second imaging resolution X-ray optics. Such optics will be critical to the development next decade of astronomical X-ray observatories such as SMART-X, the Square Meter Arc Second Resolution X-ray Telescope. SMART-X is the logical heir to Chandra, with 30 times the collecting area and Chandra-like imaging resolution, and will greatly expand the discovery space opened by Chandra’s exquisite imaging resolution. In this paper we discuss deposition of thin film piezoelectric material on flat glass mirrors. For the first time, we measured the local figure change produced by energizing a piezo cell - the influence function, and showed it is in good agreement with finite element modeled predictions. We determined that at least one mirror substrate material is suitably resistant to piezoelectric deposition processing temperatures, meaning the amplitude of the deformations introduced is significantly smaller than the adjuster correction dynamic range. Also, using modeled influence functions and IXO-based mirror figure errors, the residual figure error was predicted post-correction. The impact of the residual figure error on imaging performance, including any mid-frequency ripple introduced by the corrections, was modeled. These, and other, results are discussed, as well as future technology development plans.

  14. The effect of substrate bias on titanium carbide/amorphous carbon nanocomposite films deposited by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    The titanium carbide/amorphous carbon nanocomposite films have been deposited on silicon substrate by filtered cathodic vacuum arc (FCVA) technology, the effects of substrate bias on composition, structures and mechanical properties of the films are studied by scanning electron spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy and nano-indentation. The results show that the Ti content, deposition rate and hardness at first increase and then decrease with increasing the substrate bias. Maximum hardness of the titanium carbide/amorphous carbon nanocomposite film is 51 Gpa prepared at −400 V. The hardness enhancement may be attributed to the compressive stress and the fraction of crystalline TiC phase due to ion bombardment

  15. A cathodic arc enhanced middle-frequency magnetron sputter system for deposition of hard protective coatings

    International Nuclear Information System (INIS)

    A new cathode arc enhanced magnetron sputter system for deposition of hard protective coatings is reported in this article. This system consists of eight targets: four outer targets are mounted on the wall of the chamber and four inner targets are placed around the center of the chamber. The outer and inner targets form four pair targets and are powered by four middle frequency power supplies. One of the outer targets can run either in the cathode arc mode or in the magnetron sputter mode. The Ti-containing diamond-like carbon nanocomposite coatings were deposited by using this system. The prepared coating exhibits high hardness (∼20 GPa), good adhesion (critical load is 50 N), very low friction coefficient (∼0.07); and excellent tribological performance with a wear rate of 1.4 x 10-16 m3·N-l·m-1. (authors)

  16. Optimization of Weld Bead Parameters of Nickel Based Overlay Deposited by Plasma Transferred Arc Surfacing with Adequacy Test

    OpenAIRE

    Bhaskarananda Dasgupta; Pinaky Bhadury

    2014-01-01

    Plasma Transferred Arc surfacing is a kind of Plasma Transferred Arc Welding process. Plasma Transferred Arc surfacing (PTA) is increasingly used in applications where enhancement of wear, corrosion and heat resistance of materials surface is required. The shape of weld bead geometry affected by the PTA Welding process parameters is an indication of the quality of the weld. In this paper the analysis and optimization of weld bead parameters, during deposition of a Nickel based...

  17. Method of forming ultra thin film devices by vacuum arc vapor deposition

    Science.gov (United States)

    Schramm, Harry F. (Inventor)

    2005-01-01

    A method for providing an ultra thin electrical circuit integral with a portion of a surface of an object, including using a focal Vacuum Arc Vapor Deposition device having a chamber, a nozzle and a nozzle seal, depressing the nozzle seal against the portion of the object surface to create an airtight compartment in the chamber and depositing one or more ultra thin film layer(s) only on the portion of the surface of the object, the layers being of distinct patterns such that they form the circuit.

  18. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated critical to the life and economy of the advanced fossil energy systems as the higher temperatures and corrosive environments exceed the limits of known structural materials to accommodate the service conditions. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. A new development is the demonstration of advanced aluminide-based ESD coatings for erosion and wear applications. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that yields an order of magnitude increase in deposition rates and achievable coating thicknesses. Achieving this regime has required the development of advanced ESD electronic capabilities. Development is now focused on further improvements in deposition rates, system reliability when operating at process extremes, and economic competitiveness.

  19. Deposition of Functional Coatings Based on Intermetallic Systems TiAl on the Steel Surface by Vacuum Arc Plasma

    Science.gov (United States)

    Budilov, V.; Vardanyan, E.; Ramazanov, K.

    2015-11-01

    Laws governing the formation of intermetallic phase by sequential deposition of nano-sized layers coatings from vacuum arc plasma were studied. Mathematical modeling process of deposition by vacuum arc plasma was performed. In order to identify the structural and phase composition of coatings and to explain their physical and chemical behaviour XRD studies were carried out. Production tests of the hardened punching tools were performed.

  20. Structure and Properties of Cr-containing Hydrogenated Diamond-like Carbon Films Deposited by DC Filtered Cathodic Vacuum Arc Technology%磁过滤直流真空阴极弧制备含铬类金刚石膜的结构及其性能研究

    Institute of Scientific and Technical Information of China (English)

    祝土富; 沈丽如; 徐桂东; 金凡亚

    2009-01-01

    采用磁过滤直流真空阴极弧沉积技术在单晶硅片、载玻片、不锈钢片基体上制备了含铬类金刚石(Cr-DLC)膜.用光学显微镜、椭偏仪、分光光度计、X射线光电子能谱(XPS)、X射线衍射能谱(XRD)、Raman光谱、纳米硬度计、摩擦磨损仪、洛氏硬度计检测了薄膜的组分结构、光学、力学等相关特性.结果表明,硅片上的薄膜厚度为47.6nm,碳含量为89%,s p~3键占碳含量的55.15%.不锈钢片上的薄膜具有典型的DLC膜Raman光谱特征,在空气中的摩擦系数约为0.1,耐磨性能优良,膜与基体的结合性能良好.%Cr-containing hydrogenated diamond-like carbon (Cr-DLC) films were deposited on stainless steel plate, monocrystalline silicon wafer and microscope slide glass by DC filtered cathodic vacuum arc technology. The composition, structure and properties of Cr-DLC films were investigated by spec-troscopic ellipsometer, X-ray photoelectron spectroscopy(XPS), powder X-ray diffraction(XRD), spectrophotometer, Raman spectroscopy, nanoindenter, ball-on-disk tribometer, Rockwell apparatus and optical microscope. It was shown that the content of C is 89% in the film deposited on silicon wa-fer and the content of sp~3 bonding carbon atoms in the C element is 55.15%. The Raman spectra of the film deposited on stainless steel plate has the typical characteristics of DLC. The hardness and elastic modulus of the film deposited on stainless steel plate are 16.01 GPa and 142.72 GPa. The fric-tion coefficient of the film deposited on stainless steel plate is about 0.1, the film also exhibits excel-lent wear resistance and the adhesion to substrate is very well.

  1. The Chahnaly low sulfidation epithermal gold deposit, western Makran volcanic arc, southeastern Iran

    Science.gov (United States)

    Sholeh, Ali; Rastad, Ebrahim; Huston, David L.; Gemmell, J. Bruce; Taylor, Ryan D.

    2016-01-01

    The Chahnaly low-sulfidation epithermal Au deposit and nearby Au prospects are located northwest of the intermittently active Bazman stratovolcano on the western end of the Makran volcanic arc, which formed as the result of subduction of the remnant Neo-Tethyan oceanic crust beneath the Lut block. The arc hosts the Siah Jangal epithermal and Kharestan porphyry prospects, near Taftan volcano, as well as the Saindak Cu-Au porphyry deposit and world-class Reko Diq Cu-Au porphyry deposit, near Koh-i-Sultan volcano to the east-northeast in Pakistan. The host rocks for the Chahnaly deposit include early Miocene andesite and andesitic volcaniclastic rocks that are intruded by younger dacitic domes. Unaltered late Miocene dacitic ignimbrites overlie these rocks. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data yield ages between 21.8 and 9.9 Ma for the acidic-intermediate regional volcanism. The most recent volcanic activity of the Bazman stratovolcano involved extrusion of an olivine basalt during Pliocene to Quaternary times. Interpretation of geochemical data indicate that the volcanic rocks are synsubduction and calc-alkaline to subalkaline. The lack of a significant negative Eu anomaly, a listric-shaped rare earth element pattern, and moderate La/Yb ratios of host suites indicate a high water content of the source magma.

  2. p-Type Sb-Doped ZnO Thin Films Prepared with Filtered Vacuum Arc Deposition

    OpenAIRE

    David, T; Goldsmith, S.; Boxman, R. L.

    2005-01-01

    Thin p-type Sb-doped ZnO films were grown by filtered vacuum arc deposition (FVAD), on untreated glass samples. The arc cathode was prepared by dissolving Sb into molten Zn. The deposition was performed with 200 A arc current, running for 120-240 s in 0.426 Pa oxygen pressure. The film thickness was 330-500 nm. The aotmic concentration of Sb in the films was ~1.5%, whereas the O/Zn atomic concentration ratio was ~0.7. Sb incorporation into the polycrystalline ZnO matrix was concluded from XRD...

  3. Effects of filtered cathodic vacuum arc deposition (FCVAD) conditions on photovoltaic TiO2 films

    International Nuclear Information System (INIS)

    Highlights: • Titanium dioxide films were synthesized using the FCVAD technique. • Various FCVAD conditions were tested. • The TiO2 films were characterized. • The FCVAD condition effects on the film characteristics were studied. • The O2 pressure had the most important effect on the film quality. - Abstract: Titanium dioxide (TiO2) films for photovoltaic applications were synthesized using filtered cathodic vacuum arc deposition (FCVAD) technique. Various deposition conditions were tested for an optimal film formation. The conditions included the oxygen (O2) pressure which was varied from a base pressure 10−5 to 10−4, 10−3, 10−2 and 10−1 Torr, sample holder bias varied using 0 or −250 V, deposition time varied from 10, 20 to 30 min, and deposition distance varied from 1 to 3 cm. The deposited films were also annealed and compared with unannealed ones. The films under various conditions were characterized using optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy techniques. The film transparency increased and thickness decreased to a nanoscale with increasing of the O2 pressure. The transparent deposited films contained stoichiometric titanium and oxygen under the medium O2 pressure. The as-deposited films were TiO2 containing some rutile but no anatase which needed annealing to form

  4. Performance and preparation of tungsten coatings deposited onto graphite substrate by multi-arc ion plating

    International Nuclear Information System (INIS)

    Due to its high melting point, low sputtering rate and low tritium retention properties, tungsten is considered as a promising candidate material for plasma facing materials in fusion devices. Tungsten coating was deposited onto high-purity graphite substrate by multi-arc ion plating. The tungsten coating was characterized by X-ray diffraction (XRD), optical microscope (OM), scanning electron microscopy (SEM) and 3D laser scanning microscope. The results indicate that: The thickness of tungsten coating is in the range of 3μm-10μm. The results of XRD show that the oriented crystal growth of the coatings occurred along (110) crystal plane. The multi-arc ion plating method yield excellent coverage of the graphite surface, even in the open pores of the substrate. The coating is dense and homogeneous. The bond between graphite and the coating was relatively dense. The average surface roughness of the coatings is about 1.2μm. (authors)

  5. Deposition of TiN Films by Novel Filter Cathodic Arc Technique

    Institute of Scientific and Technical Information of China (English)

    NIU Er-Wu; FAN Song-Hua; LI Li; L(U) Guo-Hua; FENG Wen-Ran; ZHANG Gu-Ling; YANG Si-Ze

    2006-01-01

    A straight magnetic filtering arc source is used to deposit thin films of titanium nitride.The properties of thefilms depend strongly on the deposition process.TiN films can be deposited directly onto heated substrates in anitrogen atmosphere or onto unbiased substrates by condensing the Ti+ ion beam in about 300 eV N2+ nitrogen ionbombardment.In the latter case.the film stoichiometry is varied from an N:Ti ratio of 0.6-1.1 by controlling thearrival rates of Ti and nitrogen ions.Meanwhile,simple models are used to describe the evolution of compressivestress as function of the arrival ratio and the composition of the ion-assisted TiN films.

  6. Metal Matrix Composites Deposition in Twin Wire Arc Spraying Utilizing an External Powder Injection Composition

    Science.gov (United States)

    Tillmann, W.; Abdulgader, M.; Hagen, L.; Nellesen, J.

    2014-01-01

    The powder injection parameters, the location of the injection port, as well as the metal matrix composites are important features, which determine the deposition efficiency and embedding behavior of hard materials in the surrounding matrix of the twin wire arc-spraying process. This study investigates the applicability of external powder injection and aims to determine whether the powder injection parameters, the location, and the material combination (composition of the matrix as well as hard material) need to be specifically tailored. Therefore, the position of the injection port in relation to the arc zone was altered along the spraying axis and perpendicular to the arc. The axial position of the injection port determines the thermal activation of the injected powder. An injection behind the arc, close to the nozzle outlet, seems to enhance the thermal activation. The optimal injection positions of different hard materials in combination with zinc-, nickel- and iron-based matrices were found to be closer to the arc zone utilizing a high-speed camera system. The powder size, the mass of the particle, the carrier gas flow, and the electric insulation of the hard material affect the perpendicular position of the radial injection port. These findings show that the local powder injection, the wetting behavior of particles in the realm of the molten pool as well as the atomization behavior of the molten pool all affect the embedding behavior of the hard material in the surrounded metallic matrix. Hardness measurement by means of nanoindentation and EDX analysis along transition zones were utilized to estimate the bonding strength. The observation of a diffusion zone indicates a strong metallurgical bonding for boron carbides embedded in steel matrix.

  7. Properties of Coatings Deposited Using a Filtered Vacuum Arc Carbon Plasma Source

    International Nuclear Information System (INIS)

    A filtered vacuum arc plasma source with an adjustable cathode-anode gap was used to produce a carbon plasma for deposition of coatings on various substrates. The deposition apparatus consisted of a plasma gun, a toroidal plasma duct, a deposition chamber, and a cooled substrate holder. The plasma gun consisted of a cylindrical graphite cathode, an annular graphite anode, and a mechanism providing axial movement of the cathode to the anode. The arc was ignited in vacuum by momentarily contacting the cathode with the anode, while applying a D.C. current of 100 A between the cathode and the anode, and then withdrawing the cathode away from the anode in the axial direction, forming a cathode-anode gap of 12 mm. A carbon plasma jet passed through the anode into the toroidal duct and then to the substrate. The substrates were stainless steel and polycarbonate coupons, glass slides, and glass and polycarbonate substrates with a SnO2 coating. It was shown that the structure of the coatings deposited on stainless steel substrates depended on the negative bias voltage (Vbias) applied to the substrate. With Vbias=0, the coatings were not adherent, at Vbias =-10 V the coatings were porous, but the pore density decreased with increasing negative Vbias. At Vbias =-20-25 V the adhesion of the coating was good, and dense, hard (HV-34-60 GPa) DLC coatings were formed. At Vbias 235 V, the formation of graphite phase was observed whose area increased with increasing Vbias. Coatings deposited on polycarbonate surfaces were adherent without applying bias. However, the substrate surface was damaged due to heat flux to the substrate produced by the plasma, after a deposition duration which depended on the magnetic field strength

  8. Mechanical properties and scratch resistance of filtered-arc-deposited titanium oxide thin films on glass

    Energy Technology Data Exchange (ETDEWEB)

    Borrero-Lopez, Oscar, E-mail: oborlop@unex.es [Departamento de Ingenieria Mecanica, Energetica y de los Materiales, Universidad de Extremadura, 06071, Badajoz (Spain); School of Materials Science and Engineering, University of New South Wales NSW 2052, Sydney (Australia); Hoffman, Mark [School of Materials Science and Engineering, University of New South Wales NSW 2052, Sydney (Australia); Bendavid, Avi; Martin, Phil J. [CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield NSW 2070 (Australia)

    2011-09-01

    The mechanical properties and the scratch resistance of titanium oxide (TiO{sub 2}) thin films on a glass substrate have been investigated. Three films, with crystalline (rutile and anatase) and amorphous structures, were deposited by the filtered cathodic vacuum arc deposition technique on glass, and characterized by means of nanoindentation and scratch tests. The different damage modes (arc-like, longitudinal and channel cracks in the crystalline films; Hertzian cracks in the amorphous film) were assessed by means of optical and focused ion beam microscopy. In all cases, the deposition of the TiO{sub 2} film improved the contact-mechanical properties of uncoated glass. Crystalline films were found to possess a better combination of mechanical properties (i.e. elastic modulus up to 221 GPa, hardness up to 21 GPa, and fracture strength up to 3.6 GPa) than the amorphous film. However, under cyclic sliding contact above the critical fracture load, the amorphous film was found to withstand a higher number of cycles. The results are expected to provide useful insight for the design of optical coatings with improved contact-damage resistance.

  9. Cross-sectional STEM study of cathodic arc deposited amorphous carbon and carbon-nitride films

    International Nuclear Information System (INIS)

    Full text: The VG601 high resolution dedicated Scanning Transmission Electron Microscope (STEM) located at the University of Sydney has the capability of providing structural information with a spatial resolution of less than one nanometre. Compositional information can be obtained using either Energy Dispersive Spectroscopy (EDS) or Electron Energy Loss Spectroscopy. Each characteristic absorption edge in EELS also exhibits structure which provides information on the atomic environment of the absorbing atom. The combination of EELS and STEM therefore provides a powerful tool for analysing structure at the nanometre scale. In this work we investigate the structure of cathodic arc deposited carbon and carbon-nitride films using this EELS/STEM combination. By preparing the films in cross-section and collecting a number of spectra in a line through the film thickness (line profile), it is possible to investigate the deposition process in great detail since variations in structure with depth in the film provide information on the 'history' of film growth. In the case of carbon based materials, this technique provides a direct measure of the variations in both density and proportion of diamond-like bonding. These measurements will be used to help understand the mechanisms of film growth by cathodic arc deposition

  10. Tribological characterization of chromium nitride coating deposited by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    CrN coatings were prepared by filtered cathodic vacuum arc (FCVA) technique. The influence of the deposition parameters (nitrogen partial pressure PN2, substrate bias voltage Vs and preheating of the substrate) on the structural, mechanical and tribological properties of the FCVA CrN coatings was investigated. Further, the FCVA CrN coating was compared in dry reciprocating sliding with commercial multi-arc ion plating (MAIP) CrN coating as to friction and wear properties. Profilometer, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) were used to evaluate the wear scars and the wear mechanisms were discussed. The results showed that the structural, mechanical and tribological properties of the FCVA CrN coatings were significantly dependent on the deposition parameters. The FCVA CrN coating deposited with PN2 of 0.1 Pa, Vs of -100 V and without preheating exhibited the optimal mechanical and tribological properties. The FCVA CrN coating exhibited much better anti-abrasive and anti-spalling properties than the MAIP CrN coating, which was resulted from significant reduction of macroparticles and pitting defects by the FCVA technique. The MAIP CrN coating suffered severe concentrated wear by a combination wear mechanisms of delamination, abrasive and oxidative wear when high normal load was applied, while for the FCVA CrN coating the wear mechanisms were ultra-mild abrasive and oxidative wear.

  11. Mechanical properties and scratch resistance of filtered-arc-deposited titanium oxide thin films on glass

    International Nuclear Information System (INIS)

    The mechanical properties and the scratch resistance of titanium oxide (TiO2) thin films on a glass substrate have been investigated. Three films, with crystalline (rutile and anatase) and amorphous structures, were deposited by the filtered cathodic vacuum arc deposition technique on glass, and characterized by means of nanoindentation and scratch tests. The different damage modes (arc-like, longitudinal and channel cracks in the crystalline films; Hertzian cracks in the amorphous film) were assessed by means of optical and focused ion beam microscopy. In all cases, the deposition of the TiO2 film improved the contact-mechanical properties of uncoated glass. Crystalline films were found to possess a better combination of mechanical properties (i.e. elastic modulus up to 221 GPa, hardness up to 21 GPa, and fracture strength up to 3.6 GPa) than the amorphous film. However, under cyclic sliding contact above the critical fracture load, the amorphous film was found to withstand a higher number of cycles. The results are expected to provide useful insight for the design of optical coatings with improved contact-damage resistance.

  12. Tribological characterization of chromium nitride coating deposited by filtered cathodic vacuum arc

    Science.gov (United States)

    Mo, J. L.; Zhu, M. H.

    2009-06-01

    CrN coatings were prepared by filtered cathodic vacuum arc (FCVA) technique. The influence of the deposition parameters (nitrogen partial pressure P, substrate bias voltage Vs and preheating of the substrate) on the structural, mechanical and tribological properties of the FCVA CrN coatings was investigated. Further, the FCVA CrN coating was compared in dry reciprocating sliding with commercial multi-arc ion plating (MAIP) CrN coating as to friction and wear properties. Profilometer, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) were used to evaluate the wear scars and the wear mechanisms were discussed. The results showed that the structural, mechanical and tribological properties of the FCVA CrN coatings were significantly dependent on the deposition parameters. The FCVA CrN coating deposited with P of 0.1 Pa, Vs of -100 V and without preheating exhibited the optimal mechanical and tribological properties. The FCVA CrN coating exhibited much better anti-abrasive and anti-spalling properties than the MAIP CrN coating, which was resulted from significant reduction of macroparticles and pitting defects by the FCVA technique. The MAIP CrN coating suffered severe concentrated wear by a combination wear mechanisms of delamination, abrasive and oxidative wear when high normal load was applied, while for the FCVA CrN coating the wear mechanisms were ultra-mild abrasive and oxidative wear.

  13. High photoelectron emission from Co-diffused MgO deposited using arc plasma gun

    Science.gov (United States)

    Yamamoto, Shin-ichi; Kosuga, Hiroki

    2015-08-01

    MgO has several advantageous characteristics and has been applied in various fields. In this study, we deposited Co nanoparticles in an island pattern on a Si substrate using an arc plasma gun (APG). We subsequently formed a MgO thin film on this substrate by metal-organic decomposition (MOD), which enables the formation of films in the atmosphere, thereby yielding a double-layer structure. The MgO thin film formed on Co nanoparticles deposited using the APG with 500 pulses of arc discharge exhibited improved crystallinity and photoelectron emission at least threefold higher than that of a MgO thin film formed directly without depositing Co nanoparticles. Although the transmittance of the specimen formed by depositing Co nanoparticles was initially 30% or lower, it increased to greater than 90% after the formation of the MgO thin film and the dispersion of the Co nanoparticles in the MgO thin film during heat treatment at 900 °C. Our results clarify that the characteristics of MgO thin films are markedly improved by depositing Co nanoparticles before forming the films. The results of Kelvin probe force microscopy (KPFM) indicate that the outermost surface of the Co material had become CoO (cobalt oxide) with the dispersion of Co nanoparticles in the MgO thin film. The lattice parameter of CoO nanoparticles (an-axis lattice parameter of 4.2615 Å) after heating matches well with that of MgO (4.2126 Å). The MgO thin films that grew in conjunction with the CoO nanoparticles were highly crystallized. We successfully established a high-performance, cost-effective bottom-up process that requires no ion injection by dispersing Co nanoparticles in a MgO thin film through heat treatment.

  14. Phase determination of filtered vacuum arc deposited TiO2 thin films by optical modeling

    International Nuclear Information System (INIS)

    Thin films of TiO2 were produced using filtered vacuum arc deposition. Arc currents were 275, 300, 325 A, and the oxygen pressure during deposition was 0.93 Pa. The substrates were glass microscope slides, at temperatures of 25 oC (RT), 200 oC, and 400 oC. Film thickness was in the range 100 to 250 nm, depending on the deposition conditions. Film structure and chemical composition were determined using XRD and XPS analyses, respectively. As-deposited films were amorphous, except to two samples that were found to be crystalline (deposited with 300 A, 325 A at 400 oC), and the crystalline phase was close to that of anatase. All of the films were partially crystallized by annealing in air at 450 oC for 1 h. The O:Ti atomic concentration ratio was in the range 1.6:1-2:1, independent of deposition conditions. The optical parameters, refractive index and the extinction coefficient of the films were determined using variable angle spectroscopic ellipsometry. In addition, the optical transmission of the films were determined in the UV-VIS and IR regions. The average optical transmission in the VIS spectrum was 70-85%, affected by the interference in the film with 90% maxima and 60% minima. The refractive index at λ = 550 nm was in the range 2.4 to 2.7, depending on the deposition conditions and annealing. Using the semi-empirical model of Wemple and DiDomenico for the dielectric function below the interband absorption edge of ionic and covalent solids, the dispersion energy parameters of TiO2 (Eo, Ed) were calculated. The underlying structural order of the amorphous films was inferred by comparing the dispersion energy parameters of the amorphous films with those of crystalline TiO2. As expected, the refractive index of the amorphous films depended on the underlying phase of the film. The optical analyses indicated that the underlying phase of the amorphous films deposited on RT substrates was close to anatase, whereas the underlying phase of the amorphous films deposited

  15. Vacuum arc plasma generation and thin film deposition from a TiB2 cathode

    International Nuclear Information System (INIS)

    We have studied the utilization of TiB2 cathodes for thin film deposition in a DC vacuum arc system. We present a route for attaining a stable, reproducible, and fully ionized plasma flux of Ti and B by removal of the external magnetic field, which leads to dissipation of the vacuum arc discharge and an increased active surface area of the cathode. Applying a magnetic field resulted in instability and cracking, consistent with the previous reports. Plasma analysis shows average energies of 115 and 26 eV, average ion charge states of 2.1 and 1.1 for Ti and B, respectively, and a plasma ion composition of approximately 50% Ti and 50% B. This is consistent with measured resulting film composition from X-ray photoelectron spectroscopy, suggesting a negligible contribution of neutrals and macroparticles to the film growth. Also, despite the observations of macroparticle generation, the film surface is very smooth. These results are of importance for the utilization of cathodic arc as a method for synthesis of metal borides

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-25

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

  17. Properties of SnO2 coatings fabricated on polymer substrates using filtered vacuum arc deposition

    International Nuclear Information System (INIS)

    Transparent conducting SnO2 coatings of 0.16-1.2 μm thickness were deposited on polymer substrates using filtered vacuum arc deposition. Mechanical and electro-optical properties of the coatings were investigated. Surface topography, nano-indentation hardness and nano-scratch resistance were studied using an atomic force microscope equipped with a diamond pyramid tip. Electrical sheet conductivity and optical transmission were studied as a function of the coating thickness. The surface nanohardness of SnO2 coated polymer samples was larger by at least an order of magnitude than that of the bare polymer surfaces. Transparent and conducting SnO2 coatings reduced the light-load scratch wear rate of the polymer substrates by two to three orders of magnitude, while providing optical transmission and electrical conductivity. This combination of properties would be useful for fabricating transparent scratch resistant coatings for vehicle and aircraft windows

  18. Structure and microtribological characteristics of laser-arc deposited TiB2 thin film

    Institute of Scientific and Technical Information of China (English)

    CAO Xiankun; SHAO Tianmin; WEN Shizhu; QING Tao; QI Feng

    2004-01-01

    TiB2 thin film was deposited by laser-arc deposition method on the surface of single crystalline silicon. The morphology, composition, structure and microtribological properties of the film were studied by using XPS, XRD and atomic force/friction force microscope (AFM/FFM). The results show that TiB2 (100) preferred growth on the Si(100)substrate, TiB2(001) preferred growth on the Si(111) substrate. The TiB2 thin film was composed of TiB2 and a small amount of TiO2. The friction coefficient of TiB2 film on substrates Si (100) and Si(111) in microtribological process were 0.087 and 0.073,respectively. TiB2 thin film displayed distinct ability of anti-scratch and wear-resistance.

  19. A comparative research on magnetron sputtering and arc evaporation deposition of Ti-Al-N coatings

    International Nuclear Information System (INIS)

    Ti-Al-N coating has been proven to be an effective protective coating for machining applications. Here, the differences of cubic Ti-Al-N coatings with a similar Ti/Al atomic ratio of 1 deposited by magnetron sputtering and cathodic arc evaporation have been studied in detail. Main emphasis was laid on the characterization of thermal stability and cutting performance. Both coatings during annealing exhibit a structural transformation into stable phases c-TiN and h-AlN via an intermediate step of spiondal decomposition with the precipitation of c-AlN, however, a difference in decomposition process. Compared to sputtered coating inserts, an increase of tool life-time by 42% is obtained by evaporated coating inserts at the higher speed of 200 m/min, whereas the similar cutting life is observed at the speed of 160 m/min. It is attributed to the better stability of evaporated coating due to its later structural transformation at elevated temperature. A post-deposition vacuum annealing of both coated inserts in their corresponding temperature range of spiondal decomposition improves their cutting performance due to an increase in hardness arising from the precipitation of coherent cubic-phase nanometer-size c-AlN domains. Additionally, the sputtered coating behaves in worse oxidation resistance due to its more open structure. These behaviors can be understood considering the difference in microstructure and morphology of as deposited coatings originating from adatom mobility of deposited particles, where arc evaporation technique with higher ion to neutral ratio shows higher adatom mobility.

  20. Technological plasma source equipped with combined system of vacuum-arc discharge initiation

    International Nuclear Information System (INIS)

    The construction and the operation principle of erosion plasma source with a three-stage system of vacuum-arc discharge excitation is described. As first two step was used the modified contactless start system with plasma injector, which was widely used in standard plasma sources of the ''Bulat'' systems. The operation principle of the third stage was based on the transition of glow discharge to arc discharge. Coordinated operation of three stages during various stages of coating deposition provided significant increasing of service life and reliability of the system of vacuum-arc discharge initiation and extended the functionality of the plasma source

  1. Structure of MoCN films deposited by cathodic arc evaporation

    International Nuclear Information System (INIS)

    Molybdenum carbonitride (MoCN) coatings were deposited onto HS6-5-2 steel substrate using pure Mo targets in mixed acetylene and nitrogen atmosphere by cathodic arc evaporation. The structural properties of MoCN coatings with different carbon contents (as an effect of the C2H2 flow rate) were investigated systematically. Phase and chemical composition evolution of the coatings were characterized both by the glancing angle of X-ray diffraction (XRD) and wavelength dispersive spectrometry, respectively. These analyses have been supplemented by estimates of grain sizes and stress in the coatings. The XRD results show that the increase in acetylene flow rate causes the formation of molybdenum carbide (MoC) hexagonal phase in the coatings, a reduction of grain size and an increase in internal stress. - Highlights: • MoN and MoCN coatings were deposited by cathodic arc evaporation in nitrogen atmosphere. • MoCN coatings were formed using different acetylene flow rates. • Phase composition evolution was observed. • Crystallite size and stress were calculated

  2. Structure of MoCN films deposited by cathodic arc evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Gilewicz, A., E-mail: adam.gilewicz@tu.koszalin.pl [Koszalin University of Technology, Faculty of Technology and Education, Sniadeckich 2, 75-453 Koszalin (Poland); Jedrzejewski, R.; Kochmanska, A.E. [West Pomeranian University of Technology Szczecin, Faculty of Mechanical Engineering and Mechatronics, 19 Piastów Ave., 70-313 Szczecin (Poland); Warcholinski, B. [Koszalin University of Technology, Faculty of Technology and Education, Sniadeckich 2, 75-453 Koszalin (Poland)

    2015-02-27

    Molybdenum carbonitride (MoCN) coatings were deposited onto HS6-5-2 steel substrate using pure Mo targets in mixed acetylene and nitrogen atmosphere by cathodic arc evaporation. The structural properties of MoCN coatings with different carbon contents (as an effect of the C{sub 2}H{sub 2} flow rate) were investigated systematically. Phase and chemical composition evolution of the coatings were characterized both by the glancing angle of X-ray diffraction (XRD) and wavelength dispersive spectrometry, respectively. These analyses have been supplemented by estimates of grain sizes and stress in the coatings. The XRD results show that the increase in acetylene flow rate causes the formation of molybdenum carbide (MoC) hexagonal phase in the coatings, a reduction of grain size and an increase in internal stress. - Highlights: • MoN and MoCN coatings were deposited by cathodic arc evaporation in nitrogen atmosphere. • MoCN coatings were formed using different acetylene flow rates. • Phase composition evolution was observed. • Crystallite size and stress were calculated.

  3. Production of thin carbon stripper foils using heated-substrates in a cathodic arc deposition system

    International Nuclear Information System (INIS)

    The lifetime of carbon stripper foil can have a marked impact on the successful running of a beam line. Standard techniques for production of carbon stripper foils include evaporation of carbon (ec) and laser-pulsed ablation (Ipa). Recent work by a using Ipa has been successful in substantially increasing the lifetime of a very thin foil. The suspected mechanism for the increased lifetime of the foil is that the amorphous carbon foil is density-matched to that of graphite (around 2.26g/cc). In this work, we attempt to reproduce this result by producing carbon stripper foils with a mass-density similar to graphite using a cathodic arc deposition system. The cathodic arc is well known for the production of tetrahedral amorphous carbon: a high density, high stress form of carbon with over 90% sp3-like bonds; to reduce the density of the carbon and promote more graphitic structure, a high bias was initially attempted but this proved unsuccessful. Another method is to use a heated-substrate holder to reduce compressive stress within the deposited film. The performance of the density-matched carbon stripper foils and the implications for future production of high-quality carbon stripper foils in our laboratory will be discussed. (authors)

  4. Effects of deposition parameters on microstructure and thermal conductivity of diamond films deposited by DC arc plasma jet chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    QU Quan-yan; QIU Wan-qi; ZENG De-chang; LIU Zhong-wu; DAI Ming-jiang; ZHOU Ke-song

    2009-01-01

    The uniform diamond films with 60 mm in diameter were deposited by improved DC arc plasma jet chemical vapor deposition technique. The structure of the film was characterized by scanning electronic microcopy(SEM) and laser Raman spectrometry. The thermal conductivity was measured by a photo thermal deflection technique. The effects of main deposition parameters on microstructure and thermal conductivity of the films were investigated. The results show that high thermal conductivity, 10.0 W/(K-cm), can be obtained at a CH4 concentration of 1.5% (volume fraction) and the substrate temperatures of 880-920 ℃ due to the high density and high purity of the film. A low pressure difference between nozzle and vacuum chamber is also beneficial to the high thermal conductivity.

  5. Search for novel amorphous alloys with high crystallization temperature by combinatorial arc plasma deposition

    International Nuclear Information System (INIS)

    This paper describes a combinatorial search for novel amorphous alloys with high crystallization temperatures (Tx) using combinatorial arc plasma deposition (CAPD). The CAPD technique can deposit 1089 (33 x 33) thin film samples with different compositions on a substrate at one time. These 1089 samples on the substrate are individually referred to as CAPD samples and collectively referred to as a thin film library. Thin film libraries of Ir-Zr-Fe, Ir-Zr-Al, Mo-Zr-Al, Mo-Zr-Si, Ru-Zr-Fe and Ru-Zr-Si were deposited by CAPD. The compositions and phases of the CAPD samples were measured by energy dispersive X-ray fluorescence spectrometry and X-ray diffractometry, respectively. The results revealed that each library included amorphous CAPD samples. Since it is impossible to measure the Tx, fracture strength, fracture strain and Young's modulus of the CAPD samples by conventional measurement methods, larger samples having the same compositions as the amorphous CAPD samples were fabricated by a sputtering system. Since all CAPD samples of Ir-Zr-Fe and Ir-Zr-Al were too brittle, their corresponding sputter-deposited samples were not prepared. Sputter-deposited Mo-Zr-Al, Mo-Zr-Si, Ru-Zr-Fe and Ru-Zr-Si samples with ∼50 at.% Mo- or Ru-content were fabricated, and Tx and mechanical properties of these sputter-deposited samples were evaluated. All the sputter-deposited samples of Mo-Zr-Al and Mo-Zr-Si showed high Tx exceeding 973 K and as well as brittle characteristics. Ru50Zr35Fe10 samples showed high Tx exceeding 1273 K and a low fracture strength of 0.26 GPa. Samples of Ru51Zr5Si44 showed a high Tx of 923 K and a high fracture strength of 1.25 GPa

  6. Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California

    Science.gov (United States)

    John, David A.; du Bray, Edward A.; Henry, Christopher D., (compiler); Vikre, Peter

    2015-01-01

    Many epithermal gold-silver deposits are temporally and spatially associated with late Oligocene to Pliocene magmatism of the southern ancestral Cascade arc in western Nevada and eastern California. These deposits, which include both quartz-adularia (low- and intermediate-sulfidation; Comstock Lode, Tonopah, Bodie) and quartz-alunite (high-sulfidation; Goldfield, Paradise Peak) types, were major producers of gold and silver. Ancestral Cascade arc magmatism preceded that of the modern High Cascades arc and reflects subduction of the Farallon plate beneath North America. Ancestral arc magmatism began about 45 Ma, continued until about 3 Ma, and extended from near the Canada-United States border in Washington southward to about 250 km southeast of Reno, Nevada. The ancestral arc was split into northern and southern segments across an inferred tear in the subducting slab between Mount Shasta and Lassen Peak in northern California. The southern segment extends between 42°N in northern California and 37°N in western Nevada and was active from about 30 to 3 Ma. It is bounded on the east by the northeast edge of the Walker Lane. Ancestral arc volcanism represents an abrupt change in composition and style of magmatism relative to that in central Nevada. Large volume, caldera-forming, silicic ignimbrites associated with the 37 to 19 Ma ignimbrite flareup are dominant in central Nevada, whereas volcanic centers of the ancestral arc in western Nevada consist of andesitic stratovolcanoes and dacitic to rhyolitic lava domes that mostly formed between 25 and 4 Ma. Both ancestral arc and ignimbrite flareup magmatism resulted from rollback of the shallowly dipping slab that began about 45 Ma in northeast Nevada and migrated south-southwest with time. Most southern segment ancestral arc rocks have oxidized, high potassium, calc-alkaline compositions with silica contents ranging continuously from about 55 to 77 wt%. Most lavas are porphyritic and contain coarse plagioclase

  7. Tribological characterization of chromium nitride coating deposited by filtered cathodic vacuum arc

    Energy Technology Data Exchange (ETDEWEB)

    Mo, J.L. [Tribology Research Institute, Traction Power State Key Laboratory, Southwest Jiaotong University, 111 Er Huan Road, Chengdu 610031 (China); Zhu, M.H., E-mail: zhuminhao@swjtu.cn [Tribology Research Institute, Traction Power State Key Laboratory, Southwest Jiaotong University, 111 Er Huan Road, Chengdu 610031 (China)

    2009-06-15

    CrN coatings were prepared by filtered cathodic vacuum arc (FCVA) technique. The influence of the deposition parameters (nitrogen partial pressure P{sub N{sub 2}}, substrate bias voltage V{sub s} and preheating of the substrate) on the structural, mechanical and tribological properties of the FCVA CrN coatings was investigated. Further, the FCVA CrN coating was compared in dry reciprocating sliding with commercial multi-arc ion plating (MAIP) CrN coating as to friction and wear properties. Profilometer, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) were used to evaluate the wear scars and the wear mechanisms were discussed. The results showed that the structural, mechanical and tribological properties of the FCVA CrN coatings were significantly dependent on the deposition parameters. The FCVA CrN coating deposited with P{sub N{sub 2}} of 0.1 Pa, V{sub s} of -100 V and without preheating exhibited the optimal mechanical and tribological properties. The FCVA CrN coating exhibited much better anti-abrasive and anti-spalling properties than the MAIP CrN coating, which was resulted from significant reduction of macroparticles and pitting defects by the FCVA technique. The MAIP CrN coating suffered severe concentrated wear by a combination wear mechanisms of delamination, abrasive and oxidative wear when high normal load was applied, while for the FCVA CrN coating the wear mechanisms were ultra-mild abrasive and oxidative wear.

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

    International Nuclear Information System (INIS)

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

  9. Deposition of TiN, TiC, and TiO2 films by filtered arc evaporation

    International Nuclear Information System (INIS)

    A filtered arc deposition process was used in the reactive deposition of macroparticle-free TiO2, TiN, and TiC films. The TiO2 films were reactively deposited by arc evaporation of titanium in an oxygen atmosphere. The films deposited onto glass substrates heated to 350degC had a rutile structure and a refractive index n633 of 2.735 and extinction coefficient k633 of 0.07. Films of TiN and TiC were prepared by reactive evaporation in nitrogen and methane respectively. The lattice parameters and preferred orientations of the deposited films were measured as a function of negative substrate bias. The films were characterized by microhardness measurements, X-ray photoelectron spectroscopy and X-ray diffraction. (orig.)

  10. Key technology of robotic welding (present status and future subjects of technology). Characteristic of the arc sensor and its future technology; Robot yosetsu no key technology gijutsu no genjo to shorai eno kadai. Arc sensor no tokusei to shorai gijutsu no kadai

    Energy Technology Data Exchange (ETDEWEB)

    Sugitani, Y. [NKK Corp., Tokyo (Japan)

    1994-10-01

    This paper describes basic characteristics of arc sensors and adaptive control of weld pool phenomena in the GMA welding. The arc sensor, utilizing the basic characteristic where change in torch height alters the current-voltage characteristics of the arc, serves for copying the groove and controlling the torch height. Therefore, to utilize the arc sensor, it is necessary to understand the dynamic characteristics of the current/voltage waveforms. The groove copy technology using the arc sensor now reaches the stage of practical use and expanded application, and thus the important future study subject is an adaptive control of weld pool. The adaptive control of the weld pool in the key hole type one-side GMA welding was studied, and it has been found that when the amount of deposition is controlled only using the wire feed rate, and the torch voltage is controlled so that the heat generation of the arc (current {times} voltage) is constant, the key hole profile and weld bead shape can be constant regardless of widely changed groove shape. The future subject is a study of the globule transition phenomenon. 30 refs., 14 figs.

  11. Graphite electrode dc arc technology development for treatment of buried wastes

    International Nuclear Information System (INIS)

    A ''National Laboratory-University-Industrial'' three-way partnership has been established between the Pacific Northwest Laboratory (PNL), Massachusetts Institute of Technology (MIT), and Electro-Pyrolysis, Inc. (EPI) to develop graphite electrode DC arc technology for the treatment of buried wastes. This paper outlines the PNL-MIT-EPI program describing a series of engineering-scale DC arc furnace tests conducted in an EPI furnace at the Plasma Fusion Center at MIT, and a description of the second phase of this program involving the design, fabrication, and testing of a pilot-scale DC arc furnace. Included in this work is the development and implementation of diagnostics to evaluate and optimize high temperature thermal processes such as the DC arc technology

  12. Research on the 2-axis cup-wheel dressing technology of arc-diamond grinding wheel

    Science.gov (United States)

    Chang, X. L.; Wu, H. Y.; Peng, Y. F.

    2014-08-01

    The precision dressing of arc-diamond wheel is very hard, expensive and time-consuming because of the super-hard diamond particles and complicated geometrical shape. This paper aims to investigate the cup-wheel dressing technology to realize the high-efficiency regeneration of the arc-diamond wheel. A two-axis cup-wheel dressing technique for precision dressing arc-diamond wheel was suggested and tested. The dressing mechanism of 2-axis cup-wheel was studied. The dressing algorithm and error compensation method were further investigated to improve the dressing precision and efficiency. The experimental results show that the 2-axis cup-wheel dressing technique is valid and applicable to realize the precision dressing of arc-diamond wheel. The machined optical surface condition was apparently improved with the cup-wheel dressed diamond wheel and even became much better when the error compensation algorithm was performed on the arc-diamond wheel.

  13. The electrochemical behavior of thermally oxidized CrN coatings deposited on steel by cathodic arc plasma deposition

    International Nuclear Information System (INIS)

    Cathodic arc plasma deposition of the CrN coating has been applied to an industrial scale to improve the corrosion resistance of the AISI 304 stainless steel. Thermal oxidation in air was carried out at the temperature of 500 and 800 deg. C for 1 h. The effect of the thermal oxidation on the aqueous corrosion behavior of the CrN/304s assembly was investigated in this study. The composition and structure of the CrN coatings were studied by the grazing X-ray diffraction (GXRD), electron probe X-ray microanalyzer (EPMA), and X-ray photoelectron spectroscopy (XPS). The polarization resistance (Rp) of all samples was measured and compared in terms of a polarization resistance resulting from electrochemical impedance spectroscopy (EIS) in a mixture of 0.5 M H2SO4 + 1 M NaCl solution. The results indicated that the corrosion resistance of the CrN coated steel oxidized at 500 deg. C is significantly reduced. On the contrary, the electrochemical behavior of the CrN coated steel oxidized at 800 deg. C shows better corrosion resistance than the one oxidized at 500 deg. C and as-deposited steel. After thermal oxidation at 800 deg. C, the oxide layer formed on top of CrN coating enhances the corrosion protection of the CrN coated steel

  14. Environmental application research and future plans in plasma arc technology at the georgia institute of technology

    International Nuclear Information System (INIS)

    This paper summarizes the facilities and past, current, and future research efforts at the georgia institute of technology plasma Arc research facility established in 1992. This research facility was established specifically to develop and test applications related to waste management and various remediation concepts. The results of research programs in the vitrification of asbestos materials, municipal incinerator ash, and in situ testing programs, including soil remediation, waste to energy research, landfill remediation and capacity management. The presentation will also include conference and symposium announcements and invitations. 9 tabs

  15. X-ray elastic constants of chromium nitride films deposited by arc-ion plating

    International Nuclear Information System (INIS)

    Thin films have been successfully utilized to improve the property of mechanical components. However, it is generally known that mechanical properties, such as elastic constants and tensile strength of thin films, are different from those of bulk material, and they are not known in the present state. In many times, x-ray stress measurement revealed a very high compressive residual stress state in the film when bulk elastic constants were used in the stress calculation. The purpose of this research is to investigate the elastic constants of chromium nitride (CrN) films. The film was deposited on austenitic stainless steel (JIS: SUS304) substrates by the arc-ion-plating (AIP) method under the following conditions: the pressure of nitrogen atmosphere was maintained at 2.63 Pa, the substrate temperature of about 573 K, the arc discharge current of 100 A, the bias voltage between -300 and -100 V, and the substrate rotating rate at 3 rpm. The lattice strain of CrN films was measured by x-ray method at various loading stages and the x-ray elastic constants of CrN films were evaluated

  16. GaN thin film deposition on glass and PET substrates by thermionic vacuum arc (TVA)

    Energy Technology Data Exchange (ETDEWEB)

    Pat, Suat, E-mail: suatpat@ogu.edu.tr [Eskisehir Osmangazi University, Physics Department, 26480 (Turkey); Korkmaz, Şadan; Özen, Soner [Eskisehir Osmangazi University, Physics Department, 26480 (Turkey); Şenay, Volkan [Bayburt University, Primary Science Education Department, 69000 (Turkey)

    2015-06-01

    In this paper, GaN thin film production was realized by thermionic vacuum arc (TVA), a plasma deposition technique, for the first time. We present a new deposition mechanism for GaN thin films with a very short production time. Microstructure properties of samples were analyzed by X-ray diffractometry. The peak at 2θ = 72.88° corresponding to GaN (0004) was detected in XRD spectra. The surface morphology of the deposited GaN films was analyzed using field emission scanning electron microscopy and atomic force microscopy. The surface properties of the produced samples are quite different. The average roughness values were determined to be 0.48 nm for GaN/PET and 1.17 nm for GaN/glass. The optical properties (i.e., refractive index and reflection) were determined using an interferometer. Moreover, the obtained optical data were compared with bulk GaN materials. The refractive indexes were measured as 2.2, 3,0 and 2,5 for the GaN/glass, GaN/PET and bulk GaN, respectively. The transparencies of the different GaN-coated substrates are nearly the same. The obtained band gap values were measured in the energy range of 3.3–3.5 eV. TVA is a novel non-reactive plasma technique for the generation of metal organic thin films. The main advantage of this method is its fast deposition rate without any loss in the quality of the films. - Highlights: • A new GaN thin film growth method is introduced. • Microstructure, surface and optical properties were characterized. • GaN/glass and GaN/PET were produced by a different plasma deposition method.

  17. GaN thin film deposition on glass and PET substrates by thermionic vacuum arc (TVA)

    International Nuclear Information System (INIS)

    In this paper, GaN thin film production was realized by thermionic vacuum arc (TVA), a plasma deposition technique, for the first time. We present a new deposition mechanism for GaN thin films with a very short production time. Microstructure properties of samples were analyzed by X-ray diffractometry. The peak at 2θ = 72.88° corresponding to GaN (0004) was detected in XRD spectra. The surface morphology of the deposited GaN films was analyzed using field emission scanning electron microscopy and atomic force microscopy. The surface properties of the produced samples are quite different. The average roughness values were determined to be 0.48 nm for GaN/PET and 1.17 nm for GaN/glass. The optical properties (i.e., refractive index and reflection) were determined using an interferometer. Moreover, the obtained optical data were compared with bulk GaN materials. The refractive indexes were measured as 2.2, 3,0 and 2,5 for the GaN/glass, GaN/PET and bulk GaN, respectively. The transparencies of the different GaN-coated substrates are nearly the same. The obtained band gap values were measured in the energy range of 3.3–3.5 eV. TVA is a novel non-reactive plasma technique for the generation of metal organic thin films. The main advantage of this method is its fast deposition rate without any loss in the quality of the films. - Highlights: • A new GaN thin film growth method is introduced. • Microstructure, surface and optical properties were characterized. • GaN/glass and GaN/PET were produced by a different plasma deposition method

  18. Friction and wear of TiCN coatings deposited by filtered arc

    Energy Technology Data Exchange (ETDEWEB)

    Huang, S.W.; Ng, K.; Samandi, M. [Wollongong Univ. NSW (Australia). Department of Materials Engineering

    1998-06-01

    A series of macroparticle-free TiN, TiCN and TiC coatings were deposited on 316 austenitic stainless steel using a titanium target in a filtered arc deposition system and reactive mixtures of CH4 and N2 gases. The microhardness of the coatings were measured by using an Ultra Microhardness Indentation System (UMIS-2000). The wear and friction of the coatings were assessed under controlled test conditions in a pin-on-disc tribometer. The results show a significant increase in microhardness and wear resistance as the CH4 :N2 gas flow rate ratio is increased. At lower load (14N), all coatings exhibited low friction and wear. At higher load (25N), the higher carbon content TiCN and TiC coatings showed a much lower friction and wear compared to TiN and low carbon TiCN. The topographical examination of coatings and worn surfaces established that the self-lubricating effect of the carbonaceous particles condensed from the plasma during the deposition was primarily responsible for the low friction and wear regime. (authors). Extended abstract. 6 refs., 1 tab., 2 figs.

  19. Friction and wear of TiCN coatings deposited by filtered arc

    International Nuclear Information System (INIS)

    A series of macroparticle-free TiN, TiCN and TiC coatings were deposited on 316 austenitic stainless steel using a titanium target in a filtered arc deposition system and reactive mixtures of CH4 and N2 gases. The microhardness of the coatings were measured by using an Ultra Microhardness Indentation System (UMIS-2000). The wear and friction of the coatings were assessed under controlled test conditions in a pin-on-disc tribometer. The results show a significant increase in microhardness and wear resistance as the CH4 :N2 gas flow rate ratio is increased. At lower load (14N), all coatings exhibited low friction and wear. At higher load (25N), the higher carbon content TiCN and TiC coatings showed a much lower friction and wear compared to TiN and low carbon TiCN. The topographical examination of coatings and worn surfaces established that the self-lubricating effect of the carbonaceous particles condensed from the plasma during the deposition was primarily responsible for the low friction and wear regime. (authors)

  20. Macroparticles in Ti-Si-N-coatings deposited from vacuum-arc plasma with ion implantation

    International Nuclear Information System (INIS)

    The results of experiments on research of macroparticles hitting TiSiN-coatings during vacuum-arc deposition from direct plasma stream with PBII and D method are presented. Sintered titanium-silicon powder composite was applied as a cathode material. The effect associated with the depression of macroparticles capture by growing TiSiN-coating as a result of increase of negative bias pulse on substrate simultaneous with periodic high-voltage negative potential pulses was found out. The depression of macroparticles capture at the increase of bias pulse with PBII and D technique takes a place under two factors. The main factor is electrostatic reflection of a large share of the negatively charged macroparticles stream. The second factor is the dispersion of macroparticles, surmounting electrostatic repulsion and 'stuck' to the coating surface.

  1. Cathodic arc deposition of nitrogen doped tetrahedral amorphous carbon for computer memories

    International Nuclear Information System (INIS)

    Much interest has been shown in the use of tetrahedral amorphous carbon (ta-C) deposited by filtered cathodic arc as an inexpensive, easily produced, wide band-gap semiconductor in the fabrication of electronic devices. Around the world much of this interest has been in its potential use as a low electron-affinity field emitter for flat-screen displays. Recent observations of a nonvolatile memory effect in nitrogen doped ta-C at the University of Sydney suggest that new possibilities may exist for its use as a means of non-volatile digital information storage. Devices with switching times of 100 μs, read times of 100 ns, and effective memory retention times of the order of months have been fabricated. Nonvolatile memory phenomena observed in the electrical characteristics of nitrogen doped ta-C thin films suggests such traps may be useful as a means of digital information storage

  2. The multilayered structure of ultrathin amorphous carbon films synthesized by filtered cathodic vacuum arc deposition

    KAUST Repository

    Wang, Na

    2013-08-01

    The structure of ultrathin amorphous carbon (a-C) films synthesized by filtered cathodic vacuum arc (FCVA) deposition was investigated by high-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoelectron spectroscopy. Results of the plasmon excitation energy shift and through-thickness elemental concentration show a multilayered a-C film structure comprising an interface layer consisting of C, Si, and, possibly, SiC, a buffer layer with continuously increasing sp 3 fraction, a relatively thicker layer (bulk film) of constant sp 3 content, and an ultrathin surface layer rich in sp 2 hybridization. A detailed study of the C K-edge spectrum indicates that the buffer layer between the interface layer and the bulk film is due to the partial backscattering of C+ ions interacting with the heavy atoms of the silicon substrate. The results of this study provide insight into the minimum thickness of a-C films deposited by FCVA under optimum substrate bias conditions. Copyright © 2013 Materials Research Society.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

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

  4. Engaging ArcForm in Science and Technology Studies

    DEFF Research Database (Denmark)

    Allsopp, Benjamin Brink

    meanings are expressed. It also supports ways of being more precise than in normal prose text, but its foundation on natural language suggests that it is a form of NL on par with spoken and written form rather than a simple notation or an entirely new language. 2) It presents separate meanings/thoughts as......ArcForm is a non-linear form of general-purpose human language. It is designed as an alternative to paragraphs of text for intellectual collaboration (Allsopp 2013). It combines three areas of notational value. 1) It is similar to natural language (NL): both in its expressiveness and in the way...

  5. Deposition of thin layers of boron nitrides and hydrogenated microcrystalline silicon assisted by high current direct current arc plasma

    International Nuclear Information System (INIS)

    In the frame of this thesis, a high current direct current arc (HCDCA) used for the industrial deposition of diamond, has been adapted to study the deposition of two types of coatings: a) boron nitride, whose cubic phase is similar to diamond, for tribological applications, b) hydrogenated microcrystalline silicon, for applications in the semiconductor fields (flat panel displays, solar cells,...). For the deposition of these coatings, the substrates were placed in the diffusion region of the arc. The substrate heating is mainly due to atomic species recombining on its surface. The deposition temperature, varying from 300 to 900 oC according to the films deposited, is determined by the substrate position, the arc power and the injected gas fluxes, without the use of any external heating or cooling system. Measurements performed on the arc plasma show that the electronic temperature is around 2 eV (23'000 K) while the gas temperature is lower than 5500 K. Typical electronic densities are in the range of 1012-101'3 cm-3. For the deposition of boron nitride films, different boron precursors were used and a wide parameter range was investigated. The extreme difficulty of synthesising cubic boron nitride films by chemical vapour deposition (CVD) did not allow to stabilize the cubic phase of boron nitride in HCDCA. Coatings resulted in hexagonal or amorphous boron nitride with a chemical composition close to stoichiometric. The presence of hydrogen leads to the deposition of rough and porous films. Negative biasing of the samples, for positive ion bombardment, is commonly used to stabilize the cubic phase. In HCDCA and in our biasing range, only a densification of the films could be observed. A boron nitride deposition plasma study by infrared absorption spectroscopy in a capacitive radio frequency reactor has demonstrated the usefulness of this diagnostic for the understanding of the various chemical reactions which occur in this kind of plasma. Diborane dissociation

  6. Low temperature deposition of tantalum diffusion barrier by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    Tantalum (Ta) diffusion barrier films were deposited on un-patterned and patterned silicon substrates at ambient temperature and without substrate bias by filtered cathodic vacuum arc (FCVA). The films were characterized by atomic force microscopy, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, four-point resistivity probe and surface profilometer. It was found that the Ta film was 750 A thick and free of C and O except for surface contamination. The film morphology was smooth and uniform with root-mean-square roughness of ∼0.82 A. The Ta film was polycrystalline β phase with a mean grain size of ∼3 nm and possessed a dense microstructure, which are ascribed to the high energy of the condensing species in FCVA. It was shown that the Ta filling of the trenches (0.33 μm wide, 1 : 1 aspect ratio) was very conformal and quite uniform. Also, it was preliminarily found that at the Ta film was effective against diffusion of Cu into Si at 600 deg. C

  7. Weld metal microstructures of hardfacing deposits produced by self-shielded flux-cored arc welding

    International Nuclear Information System (INIS)

    The molten pool weld produced during self-shielded flux-cored arc welding (SSFCAW) is protected from gas porosity arising from oxygen and nitrogen by reaction ('killing') of these gases by aluminium. However, residual Al can result in mixed micro-structures of δ-ferrite, martensite and bainite in hardfacing weld metals produced by SSFCAW and therefore, microstructural control can be an issue for hardfacing weld repair. The effect of the residual Al content on weld metal micro-structure has been examined using thermodynamic modeling and dilatometric analysis. It is concluded that the typical Al content of about 1 wt% promotes δ-ferrite formation at the expense of austenite and its martensitic/bainitic product phase(s), thereby compromising the wear resistance of the hardfacing deposit. This paper also demonstrates how the development of a Schaeffler-type diagram for predicting the weld metal micro-structure can provide guidance on weld filler metal design to produce the optimum microstructure for industrial hardfacing applications.

  8. Layer Formation by Resputtering in Ti-Si-C Hard Coatings during Large Scale Cathodic Arc Deposition

    OpenAIRE

    Eriksson, Anders; Zhu, Jianqiang; Ghafoor, Naureen; Johansson, Mats; Sjölen, Jacob; Jensen, Jens; Odén, Magnus; Hultman, Lars; Rosén, Johanna

    2011-01-01

    This paper presents the physical mechanism behind the phenomenon of self-layering in thin films made by industrial scale cathodic arc deposition systems using compound cathodes and rotating substrate fixture. For Ti-Si-C films, electron microscopy and energy dispersive x-ray spectrometry reveals a trapezoid modulation in Si content in the substrate normal direction, with a period of 4 to 23 nm dependent on cathode configuration. This is caused by preferential resputtering of Si by the energet...

  9. Room temperature deposition of highly dense TiO2 thin films by filtered cathodic vacuum arc

    Science.gov (United States)

    Guillén, E.; Heras, I.; Rincón Llorente, G.; Lungwitz, F.; Alcon-Camas, M.; Escobar-Galindo, R.

    2015-08-01

    A systematic study of TiO2 films deposited by dc filtered cathodic vacuum arc (FCVA) was carried out by varying the deposition parameters in a reactive oxygen atmosphere. The influence of the oxygen partial pressure on film properties is analyzed. Composition was obtained by Rutherford backscattering spectroscopy (RBS) measurements, which also allow us to obtain the density of the films. Morphology of the samples was studied by scanning electron microscopy (SEM) and their optical properties by ellipsometry. Transparent, very dense and stoichiometric TiO2 films were obtained by FCVA at room temperature.

  10. Optimization of Weld Bead Parameters of Nickel Based Overlay Deposited by Plasma Transferred Arc Surfacing with Adequacy Test

    Directory of Open Access Journals (Sweden)

    Bhaskarananda Dasgupta

    2014-07-01

    Full Text Available Plasma Transferred Arc surfacing is a kind of Plasma Transferred Arc Welding process. Plasma Transferred Arc surfacing (PTA is increasingly used in applications where enhancement of wear, corrosion and heat resistance of materials surface is required. The shape of weld bead geometry affected by the PTA Welding process parameters is an indication of the quality of the weld. In this paper the analysis and optimization of weld bead parameters, during deposition of a Nickel based alloy Colmonoy on stainless steel plate by plasma transferred arc surfacing, are made and values of process parameters to produce optimal weld bead geometry are estimated. The experiments are conducted based on a five input process parameters and mathematical models are developed using multiple regression technique. The direct effects of input process parameters on weld bead geometry are discussed using graphs. Finally, optimization of the weld bead parameters, that is minimization of penetration and maximization of reinforcement and weld bead width, are made with a view to economize the input process parameters to achieve the desirable welding joint.

  11. Decontamination performance of low-pressure ARC decontamination technology using carbon monoxide gas

    International Nuclear Information System (INIS)

    We have been studying a dry surface decontamination technology using a Low-Pressure Arc, characterized by features such as less secondary wastes. To date, we have obtained results on the decontamination performance of argon Low-Pressure Arc decontamination technology for test pieces of BWR corrosion product film containing Co-60, and found that the Co-60 residual ratio was heavily dependent on the pressure in the chamber (Kanbe, et al., 2003). A Co-60 residual ratio of 20% was achieved only if the pressure in the chamber was reduced to some tens of pascals. We have investigated the performance of a Low-Pressure Arc when using carbon monoxide gas, in the expectation of an improvement in decontamination performance due to a chemical reaction caused by carbon monoxide, in addition to the heat effects of the Low-Pressure Arc. As a result, a Co-60 residual ratio of 20% or less was achieved. Nor was there any dependence of a Co-60 residual ratio on the gas fraction of the mixed gases (Ar/CO = 80/20-50/50 in volume %). A Co-60 residual ratio of 20% was the same level as in the case of a pure argon atmosphere, but was achieved even at pressures of several hundred pascals. The potential of decontamination even at pressures above several hundred pascals would have the advantage of facilitating the collection of radioactive dust using a gas flow by the proposed method. (authors)

  12. Structure and mechanical properties of Ti-Al-N coatings deposited by combined cathodic arc middle frequency magnetron sputtering

    International Nuclear Information System (INIS)

    Research highlights: → Ti-Al-N coatings were deposited on Si and WC substrates by combined cathodic arc middle-frequency magnetron (MF) sputtering under a Ti arc power of 10 kW with different Al MF targets currents. The hardness of the Ti-Al-N coatings was in the range of 23-32 GPa, whereas the Young modulus values were in the range of 420-540 GPa. - Abstract: Ti-Al-N coatings were deposited on Si (1 1 1) and WC substrates by combined cathodic arc middle-frequency magnetron (MF) sputtering under a Ti arc power of 10 kW and with different Al MF targets currents. X-ray diffraction patterns (XRD) showed that the Ti-Al-N coatings were polycrystallize with a preferred (1 1 1) orientation at 2θ = 43.7o. The (1 1 1) diffraction showed a decrease in peak intensity but a increase in FWHM values with the increasing of Al contents. Nano-meter sized TiN crystal grains distinguished by the lattice fringe contrast were verified by plan-view transmission electron (TEM) and selected area electron diffraction (SAED) images. With the increasing of MF sputter currents from 5 to 20 A, the Al contents in the Ti-Al-N coatings monotonically increased from 4.8 to 10.8 at.%, whereas the N and O contents were nearly constant. The hardness of the Ti-Al-N coatings was in the range of 23-32 GPa, and the Young modulus values were in the range of 420-540 GPa.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lukaszkowicz, Krzysztof, E-mail: krzysztof.lukaszkowicz@polsl.pl [Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego St. 18A, 44-100 Gliwice (Poland); Sondor, Jozef, E-mail: j.sondor@liss.cz [LISS, a.s., Dopravni 2603, 756 61 Roznov p.R. (Czech Republic); Balin, Katarzyna, E-mail: katarzyna.balin@us.edu.pl [A. Chełkowski Institute of Physic, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Kubacki, Jerzy, E-mail: jerzy.kubacki@us.edu.pl [A. Chełkowski Institute of Physic, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)

    2014-09-01

    Highlights: • The chemical composition of the CrAlSiN + DLC coatings was studied. • The coatings have nanostructural character with fine crystallites. • Their average size grain is less than 10 nm. • The coatings demonstrate friction coefficient within the range 0.05–0.07. • The coating demonstrated a dense cross-sectional morphology as well as good adhesion to the substrate. - Abstract: Coating system composed of CrAlSiN film covered by diamond-like carbon (DLC)-based lubricant, deposited on hot work tool steel substrate was the subject of the research. The CrAlSiN and DLC layers were deposited by PVD lateral rotating ARC-cathodes (LARC) and PACVD technology on the X40CrMoV5-1 respectively. HRTEM investigation shows an amorphous character of DLC layer. It was found that the tested CrAlSiN layer has a nanostructural character with fine crystallites while their average size is less than 10 nm. Based on the XRD pattern of the CrAlSiN, the occurrence of fcc phase was only observed in the coating, the texture direction 〈3 1 1〉 is perpendicular to the sample surface. Combined SEM, AES and ToF-SIMS studies confirmed assumed chemical composition and layered structure of the coating. The chemical distribution of the elements inside the layers and at the interfaces was analyzed by SEM and AES methods. It was shown that additional CrN layer is present between substrate and CrAlSiN coating. The atomic concentration of the particular elements of DLC and CrAlSiN layer was calculated from the XPS measurements. In sliding dry friction conditions the friction coefficient for the investigated elements is set in the range between 0.05 and 0.07. The investigated coating reveals high wear resistance. The coating demonstrated a dense cross-sectional morphology as well as good adhesion to the substrate.

  14. Cascadia subducting plate fluids channelled to fore-arc mantle corner: ETS and silica deposition

    Science.gov (United States)

    Hyndman, R. D.; McCrory, P. A.; Wech, A.; Kao, H.; Ague, J.

    2015-06-01

    In this study we first summarize the constraints that on the Cascadia subduction thrust, there is a 70 km gap downdip between the megathrust seismogenic zone and the Episodic Tremor and Slip (ETS) that lies further landward; there is not a continuous transition from unstable to conditionally stable sliding. Seismic rupture occurs mainly offshore for this hot subduction zone. ETS lies onshore. We then suggest what does control the downdip position of ETS. We conclude that fluids from dehydration of the downgoing plate, focused to rise above the fore-arc mantle corner, are responsible for ETS. There is a remarkable correspondence between the position of ETS and this corner along the whole margin. Hydrated mineral assemblages in the subducting oceanic crust and uppermost mantle are dehydrated with downdip increasing temperature, and seismic tomography data indicate that these fluids have strongly serpentinized the overlying fore-arc mantle. Laboratory data show that such fore-arc mantle serpentinite has low permeability and likely blocks vertical expulsion and restricts flow updip within the underlying permeable oceanic crust and subduction shear zone. At the fore-arc mantle corner these fluids are released upward into the more permeable overlying fore-arc crust. An indication of this fluid flux comes from low Poisson's Ratios (and Vp/Vs) found above the corner that may be explained by a concentration of quartz which has exceptionally low Poisson's Ratio. The rising fluids should be silica saturated and precipitate quartz with decreasing temperature and pressure as they rise above the corner.

  15. Influences of deposition parameters on the microstructure and properties of nanostructural TiN films synthesized by filtered cathodic arc plasma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yujuan; YAN Pengxun; WU Zhiguo; ZHANG Pingyu

    2005-01-01

    Titanium nitride (TiN) films with nanostructure were prepared at ambient temperature on a (111) silicon substrate by the filtered cathodic arc plasma (FCAP) technology with an in-plane "S" filter. The effects of deposition parameters on the grain size, texture and nano-hardness of the films were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electon diffraction indicated that increasing either negative subs~ate bias or argon flow promoted the formation of (111) preferred orientation. High argon flow leads to biaxial texture. The micro-hardness of the TiN films as a function of grain size showed a behavior according to the Hall-Petch relation under high argon flow.

  16. Critical Analysis of Moving Heat Source Shape for ARC Welding Process of High Deposition Rate

    Czech Academy of Sciences Publication Activity Database

    Ghosh, A.; Hloch, Sergej; Chattopadhyaya, S.

    2014-01-01

    Roč. 21, č. 1 (2014), s. 95-98. ISSN 1330-3651 Institutional support: RVO:68145535 Keywords : Gaussian heat distribution * oval heat source shape * Submerged Arc Welding Subject RIV: JQ - Machines ; Tools Impact factor: 0.579, year: 2014 http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=172337

  17. InGaN thin film deposition on Si(100) and glass substrates by termionic vacuum arc

    Science.gov (United States)

    Erdoğan, E.; Kundakçı, M.; Mantarcı, A.

    2016-04-01

    Group-III nitride semiconductors covering infrared, visible and ultraviolet spectral range has direct band gaps changing from 0,7 eV (InN) to 3,4 eV (GaN). LEDs emit red, blue, green light, ultraviolet (UV) laser diodes (LD), UV light detectors and high power electronic devices are obtained and commercialized based on group-III nitride materials. InGaN semiconductor can be deposited by different techniques such as molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD). In this study, InGaN thin films were prepared on Si and glass substrates as well as on GaN layer by termionic vacuum arc (TVA) which is a plasma asisted thin film deposition technique. The film was deposited at 10-6 torr working pressure, 18A filament current. Plasma was produced at 200 V with 0,6A plasma current. The purpose of this research is to investigate the properties of InGaN thin films. X-ray diffraction (XRD) spectrophotometer was used to analyze microstructure of the deposited films. Scanning electon microscopy (SEM) were used for surface morphology characterizations. Compositional analysis was done by energy dispersive X-ray spectroscopy (EDAX).

  18. Physical characteristics, structure and stress state of vacuum-arc TiN coating, deposition on the substrate when applying high-voltage pulse during the deposition

    International Nuclear Information System (INIS)

    Method of vacuum-arc deposition with ion implantation, (mode PBIID) obtained by coating of titanium nitride with a hardness of 62 GPa and reaches a high resistance to wear during the cutting. Submission of high-voltage pulses results in the formation of a stable structural state of titanium with cubic mononitride (structural type NaCl) crystal lattice. Comparison of the structure and stress state of titanium nitride coatings obtained in the usual way without additional supply of high-voltage pulses to the substrate during the deposition and the imposition of such pulses, shows that the influence of the pulse characteristics are a significant decrease in crystallite size and undirected growth at low significance of potential bias on substrate (from the 'floating' around -5 to -40 V), and a significant reduction of internal stresses.

  19. Nanostructured (Ti-Zr-NbN Coatings Obtained by Vacuum-arc Deposition Method: Structure and Properties

    Directory of Open Access Journals (Sweden)

    О.V. Maksakova

    2015-12-01

    Full Text Available In the article discusses the results of the deposition of nanostructured coatings obtained by vacuum arc deposition of cathode (Ti-Zr-Nb, and analyzes their structure, morphology, elemental composition, and tribological properties (friction, wear and adhesion. The structural analysis showed the formation of an FCC phase and BCC phase in a small amount (at a chamber pressure Р = 4×10 – 3 Тоrr. The results of tribological tests showed that the friction coefficient varies from 0.61 to 0.491, and Vickers hardness from 37 to 44.57 GPa when changing (increasing the pressure in the chamber. The analysis of the elements in the tracks of friction was studied.

  20. Influence of iodine concentration on microstructure and oxidation resistance of SiB6–MoSi2 coating deposited by pulse arc discharge deposition

    International Nuclear Information System (INIS)

    Highlights: • A SiB6–MoSi2 coating was prepared by pulse arc discharge deposition (PADD). • The coating can protect C/C composites from oxidation at 1773 K for 168 h. • Influence of iodine concentration on oxidation resistance was investigated. • The failure of the oxidation resistant coating was investigated. - Abstract: To improve the oxidation resistance of carbon/carbon (C/C) composites, a SiB6–MoSi2 coating was prepared by a novel pulse arc discharge deposition (PADD). The influence of iodine concentration on thickness, compactness and oxidation resistance of the multilayer coatings were investigated. Results show that the oxidation resistance of the multilayer coatings was improved with the increase of iodine concentration from 2.0 to 3.0 g L−1. The SiB6–MoSi2 coating prepared at iodine concentration of 3.0 g L−1 can protect C/C composites from oxidation at 1773 K in air for 168 h with a weight loss of 1.98%. The failure of the multilayer coatings is due to the volatilization of the multilayer coatings and the escape of CO and CO2

  1. Structural and optical characteristics of filtered vacuum arc deposited N:TiO{sub x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Çetinörgü-Goldenberg, E., E-mail: edacetinorgu@gmail.com [Electrical Discharge and Plasma Laboratory, Tel Aviv University, POB 39040, Tel Aviv 69978 (Israel); Burstein, L. [Wolfson Applied Materials Research Center, Tel Aviv University, POB 39040, Tel Aviv 69978 (Israel); Chayun-Zucker, I.; Avni, R.; Boxman, R.L. [Electrical Discharge and Plasma Laboratory, Tel Aviv University, POB 39040, Tel Aviv 69978 (Israel)

    2013-06-30

    Nitrogen doped titanium oxide (N:TiO{sub x}) thin films were deposited using filtered vacuum arc deposition. The X-ray diffraction patterns of the TiO{sub 2} thin films deposited in a pure oxygen environment indicated that films were polycrystalline in the anatase phase, while films deposited in an atmosphere in which the N{sub 2} fraction was greater than 9% were amorphous, for substrate temperatures up to 500 °C. Annealing at 400 °C in N{sub 2} for 1 h generated polycrystalline films with anatase phase, independent of %N{sub 2} during deposition. Film surface roughness increased from 0.5 up to 3.2 nm when the substrate temperature was increased from room temperature to 500 °C for films deposited in a 41%N{sub 2}. X-ray photoelectron spectroscopy analysis indicated that all films deposited in pure oxygen were stoichiometric TiO{sub 2}. N content in the films increased with %N{sub 2} in the deposition atmosphere, however the N-content in the film, 1-5 at.% N, was much less than that in the gas mixture (9–69%N{sub 2}). Annealing decreased the N-content in these films to < 1 at.%. In addition, the data revealed that all N:TiO{sub x} films had two main N 1s components, at 396–397 eV and at 399–400 eV, associated with substitutional and interstitial nitrogen, respectively. Transmission data indicated that the average transmission of films deposited at lower N{sub 2} partial pressures (< 41%) was approximately 80%, and it decreased to ∼ 50% for higher %N{sub 2}. The absorption edge of the films shifted to longer wavelengths with increased substrate temperature and %N{sub 2}, from ∼ 380 nm up to ∼ 485 nm for films deposited with 41%N{sub 2} and a substrate temperature of 500 °C. - Highlights: • Amorphous films were deposited in N{sub 2} atmosphere (> 9%). • Film surface roughness decreased with %N{sub 2} in the total deposition pressure. • Two main N 1s peaks associated with substitutional and interstitial nitrogen. • Absorption edge shifted to

  2. Bioactive calcium phosphate coating formed on micro-arc oxidized magnesium by chemical deposition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Hu, J., E-mail: hujin@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ding, Z.K.; Wang, C. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-01-01

    In order to improve the bioactivity of the micro-arc oxidized magnesium, a calcium phosphate coating was formed on the surface of micro-arc oxidized magnesium using a chemical method. The microstructures of the substrate and the calcium phosphate coating before and after the simulated body fluids (SBF) incubation were characterized by X-ray diffraction, Fourier-transformed infrared spectroscopy and scanning electron microscopy. The results showed that the calcified coating was composed of calcium deficient hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD). After SBF incubation, some new apatite formation on the calcified coating surface from SBF could be found. The corrosion behaviours of the samples in SBF were also investigated by potentiodynamic polarization curves and immersion tests. The results showed that calcium phosphate coating increased the corrosion potential, and decreased the hydrogen gas release.

  3. Polymer Matrix Composites using Fused Deposition Modeling Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fused deposition modeling (FDM) is an additive manufacturing technology that allows fabrication of complex three-dimensional geometries layer-by-layer. The goal of...

  4. Panel 1 - comparative evaluation of deposition technologies

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, G.R.; Stodolsky, F. [Argonne National Lab., IL (United States); Benson, D.K.; Pitts, R.J. [National Renewable Energy Lab., Golden, CO (United States); Bhat, D.G. [GTE Valenite Corp., Troy, MI (United States); Yulin Chen [Allison Gas Turbine Division, GM, Indianapolis, IN (United States); Gat, R.; Sunkara, M.K. [Case Western Reserve Univ., Cleveland, OH (United States); Kelly, M. [Stanford Univ., CA (United States); Lawler, J.E. [Univ. of Wisconsin, Madison (United States); Nagle, D.C. [Martin Marietta Labs., Baltimore, MD (United States); Outka, D. [Sandia National Laboratories, Livermore, CA (United States); Revankar, G.S. [Deere & Co., Moline, IL (United States); Subramaniam, V.V. [Ohio State Univ., Columbus (United States); Wilbur, P.J. [Colorado State Univ., Fort Collins (United States); Mingshow Wong [Northwestern Univ., Evanston, IL (United States); Woolam, W.E. [Southwest Research Inst., Arlington, VA (United States)

    1993-01-01

    This working group attempted to evaluate/compare the different types of deposition techniques currently under investigation for depositing diamond and diamond-like carbon films. A table lists the broad types of techniques that were considered for depositing diamond and diamond-like carbon films. After some discussion, it was agreed that any evaluation of the various techniques would be dependent on the end application. Thus the next action was to list the different areas where diamond and DLC films could find applications in transportation. These application areas are listed in a table. The table intentionally does not go into great detail on applications because that subject is dealt with specifically by Panel No. 4 - Applications To Transportation. The next action concentrated on identifying critical issues or limitations that need to be considered in evaluating the different processes. An attempt was then made to rank different broad categories of deposition techniques currently available or under development based on the four application areas and the limitations. These rankings/evaluations are given for diamond and DLC techniques. Finally, the working group tried to identify critical development and research issues that need to be incorporated into developing a long-term program that focuses on diamond/DLC coatings for transportation needs. 5 tabs.

  5. Spectroscopic investigation of vacuum-arc anode plasmas for thin film deposition

    International Nuclear Information System (INIS)

    A vacuum-arc plasma source has been designed and tested for fabrication of thin films, which are clear of droplets. In order to avoid these droplets, the source has been designed to produce pulsed plasmas generated by the anode, and to screen the substrate against the plasma streaming away from the cathode spot. We present here spectroscopic measurements and analyses carried out in order to characterize the electron population of this anode plasma. The vacuum arc was first operated with a carbon anode of diameter 0.5 mm and an arc current of 192 A. The visible and near-infrared spectra were recorded with various resolutions, in direct view of the anode spot, with an intensified CCD camera. Dominant C+ and C2+ lines were identified and the plasma parameters deduced from their relative intensities showed that local thermal equilibrium was reached, giving an electron temperature about 3.2 eV and an electron density around 2.5x1017 cm-3. The study was extended to lower currents of 140, 92 and 65 A. The temperature and the density monotonically decreased down to about 2 eV and 1.5x1015 cm-3

  6. Friction properties of amorphous carbon ultrathin films deposited by filtered cathodic vacuum arc and radio-frequency sputtering

    International Nuclear Information System (INIS)

    The friction properties of ultrathin films of amorphous carbon (a-C) deposited on Si(100) substrates by filtered cathodic vacuum arc and radio-frequency sputtering were investigated by surface force microscopy. Deposition parameters yielding a-C films with high sp3 content were used to deposit films of thickness between 5 and 35 nm. The coefficient of friction of both types of a-C films was measured with a 1-μm-radius conical diamond tip and normal loads in the range of 20–640 μN. The results show a strong dependence of the friction properties on the surface roughness, thickness, and structure of the a-C films, which are influenced by the intricacies of the deposition method. The dependence of the coefficient of friction on normal load and the dominance of adhesion and plowing friction mechanisms are interpreted in terms of the through-thickness variation of carbon atom hybridization of the a-C films. - Highlights: • Comparison of nanoscale friction properties of ultrathin amorphous carbon films. • Friction dependence on film roughness, thickness, and structure (hybridization). • Effect of through-thickness changes in carbon atom hybridization on film friction. • Explanation of film friction trends in terms of competing friction mechanisms

  7. Friction properties of amorphous carbon ultrathin films deposited by filtered cathodic vacuum arc and radio-frequency sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Matlak, J.; Komvopoulos, K., E-mail: kyriakos@me.berkeley.edu

    2015-03-31

    The friction properties of ultrathin films of amorphous carbon (a-C) deposited on Si(100) substrates by filtered cathodic vacuum arc and radio-frequency sputtering were investigated by surface force microscopy. Deposition parameters yielding a-C films with high sp{sup 3} content were used to deposit films of thickness between 5 and 35 nm. The coefficient of friction of both types of a-C films was measured with a 1-μm-radius conical diamond tip and normal loads in the range of 20–640 μN. The results show a strong dependence of the friction properties on the surface roughness, thickness, and structure of the a-C films, which are influenced by the intricacies of the deposition method. The dependence of the coefficient of friction on normal load and the dominance of adhesion and plowing friction mechanisms are interpreted in terms of the through-thickness variation of carbon atom hybridization of the a-C films. - Highlights: • Comparison of nanoscale friction properties of ultrathin amorphous carbon films. • Friction dependence on film roughness, thickness, and structure (hybridization). • Effect of through-thickness changes in carbon atom hybridization on film friction. • Explanation of film friction trends in terms of competing friction mechanisms.

  8. Deposition and current conduction of mixed hexagonal and cubic phases of AlN/p-Si films prepared by vacuum arc discharge: Effect of deposition temperature

    International Nuclear Information System (INIS)

    Cubic and hexagonal AlN films have been prepared by vacuum arc discharge technique at different deposition temperatures 100, 200 and 300 °C. The depositions were carried out from pure aluminum targets under nitrogen gas on p-type Si substrates, with Al forming the gate in a metal–insulator–semiconductor configuration. Preferential orientations (111) and (002) of the cubic and hexagonal phases have been affirmed by X-ray diffraction analysis. The Fourier transform infrared spectra revealed the manifestation of the two phases as well. The effect of deposition temperature on the crystalline quality and texture of the films has been also investigated and the grain size of which, has been evaluated as a function of temperature. The best crystalline quality i.e., largest grain size was found to be at 200 °C. The composition and stoichiometry of the films have been determined by the time-of-flight elastic recoil detection analysis (TOF-ERDA) and Rutherford backscattering techniques. The Al/N ratio was found to be around 1, while the O content was less than 1.8%. Scanning electron microscopy and TOF-ERDA measurements demonstrated films thickness of 260 nm. Current density versus electric field and capacitance–voltage (C–V) measurements were also investigated to reveal the field emission and conduction mechanism of the Al/AlN/p-Si devices. Schottky, Pool–Frenkel and Fowler–Nordheim conduction have been found to contribute to the electron transport, and the best emission properties were manifested at 200 °C with a highest current density 525 μA/cm2 at a field 71 V/μm. From C–V curves, the density of traps has been estimated to be 18 × 109 cm−2 eV−1 indicating a good quality of the deposited films. - Highlights: • AlN films containing its cubic phase were deposited by vacuum arc discharge. • MIS capacitors of these films of (111) preferential orientation were fabricated. • The best crystalline quality was found to be at 200 °C deposition

  9. Surface free energy and microarray deposition technology

    OpenAIRE

    McHale, Glen

    2007-01-01

    Microarray techniques use a combinatorial approach to assess complex biochemical interactions. The fundamental goal is simultaneous, large-scale experimentation analogous to the automation achieved in the semiconductor industry. However, microarray deposition inherently involves liquids contacting solid substrates. Liquid droplet shapes are determined by surface and interfacial tension forces, and flows during drying. This article looks at how surface free energy and wetting considerations ma...

  10. DUPLEX Al2O3/DLC COATING ON 15SiCp/2024 ALUMINUM MATRIX COMPOSITE USING COMBINED MICROARC OXIDATION AND FILTERED CATHODIC VACUUM ARC DEPOSITION

    OpenAIRE

    WENBIN XUE; HUA TIAN; JIANCHENG DU; MING HUA; XU ZHANG; YONGLIANG LI

    2012-01-01

    Microarc oxidation (MAO) treatment produces a thick Al2O3 coating on the 15SiCp/2024 aluminum matrix composite. After pretreatment of Ti ion implantation, a thin diamond-like carbon film (DLC) was deposited on the top of polished Al2O3 coating by a pulsed filtered cathodic vacuum arc (FCVA) deposition system with a metal vapor vacuum arc (MEVVA) source. The morphology and tribological properties of the duplex Al2O3/DLC multiplayer coating were investigated by Raman spectroscopy, scanning elec...

  11. Technological mineralogy study on uranium ores in Yunji ore deposit

    International Nuclear Information System (INIS)

    Based on the study of the types and features of technological mineralogy in Yunji uranium ore deposit, the factors influencing the heap leaching are researched, and uranium occurrence state is found out. The technological mineralogy data are provided for predicting, improving, and controlling the uranium ore heap leaching process. (authors)

  12. Effect of modulation periods on the microstructure and mechanical properties of DLC/TiC multilayer films deposited by filtered cathodic vacuum arc method

    International Nuclear Information System (INIS)

    Highlights: • DLC/TiC multilayer films with different modulation periods at same modulation ratio 1:1 were deposited by FCVA. • The residual stress of DLC/TiC multilayer films decreases with the modulation periods decrease. • The hardness of the multilayer DLC films decreases with modulation periods increasing. - Abstract: The high stress of diamond-like carbon (DLC) film limits its thickness and adhesion on substrate. Multilayer structure is one approach to overcome this disadvantage. In this paper, the DLC/TiC multilayer films with different modulation periods (80 nm, 106 nm or 160 nm) at same modulation ratio of 1:1 were deposited on Si(1 0 0) wafer and Ti-6Al-4V substrate by filtered cathodic vacuum arc (FCVA) technology. X-ray diffraction (XRD), transmission electron microscopy (TEM), nanoindention and wear test were employed to investigate the effect of modulation periods on the microstructure and mechanical properties of the multilayer films. The results showed that the residual stress of the DLC/TiC multilayer films could be effectively reduced and the residual stress decreased with the modulation periods decreasing. The hardness of the DLC/TiC multilayer films increased with modulation periods decreasing. The DLC/TiC multilayer film with modulation period of 106 nm had the best wear resistance due to the good combination of hardness, ductility and low compressive stress

  13. Effect of Sample Configuration on Droplet-Particles of TiN Films Deposited by Pulse Biased Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    Yanhui Zhao; Guoqiang Lin; Jinquan Xiao; Chuang Dong; Lishi Wen

    2009-01-01

    Orthogonal experiments are used to design the pulsed bias related parameters, including bias magnitude, duty cycle and pulse frequency, during arc ion deposition of TiN films on stainless steel substrates in the case of samples placing normal to the plasma flux. The effect of these parameters on the amount and the size distribution of droplet-particles are investigated, and the results have provided sufficient evidence for the physical model, in which particles reduction is due to the case that the particles are negatively charged and repulsed from negative pulse electric field. The effect of sample configuration on amount and size distribution of the particles are analyzed. The results of the amount and size distribution of the particles are compared to those in the case of samples placing parallel to the plasma flux.

  14. Physical and Mechanical Properties of (Ti-Zr-NbN Coatings, Fabricated by Vacuum-Arc Deposition

    Directory of Open Access Journals (Sweden)

    Maksakova O.V.

    2015-08-01

    Full Text Available The coatings based on (Ti-Zr-NbN were fabricated by vacuum-arc deposition of the Ti+Zr+Nb cathodes in the nitrogen atmosphere. Their physical and mechanical properties as well as tribological characteristics have been studied. The coatings are characterized by a columnar structure, their hardness reaches 44.57 GPa. The adhesion strength of coatings reaches 66.77 GPa, the friction coefficient of the «cover – Al2O3» is 1.1. It has been determined, that the hardness of the investigated coatings significantly depends on the pressure of the reaction gas. The coatings are promising as protective coatings for friction pairs and cutting tools.

  15. Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Xiaodi Huang; Dr. J. Y. Hwang

    2005-03-28

    Steel is a basic material broadly used by perhaps every industry and individual. It is critical to our nation's economy and national security. Unfortunately, the American steel industry is losing competitiveness in the world steel production field. There is an urgent need to develop the next generation of steelmaking technology for the American steel industry. Direct steelmaking through the combination of microwave, electric arc, and exothermal heating is a revolutionary change from current steelmaking technology. This technology can produce molten steel directly from a shippable agglomerate, consisting of iron oxide fines, powdered coal, and ground limestone. This technology is projected to eliminate many current intermediate steelmaking steps including coking, pellet sintering, blast furnace (BF) ironmaking, and basic oxygen furnace (BOF) steelmaking. This technology has the potential to (a) save up to 45% of the energy consumed by conventional steelmaking; (b) dramatically reduce the emission of CO{sub 2}, SO{sub 2}, NO{sub x}, VOCs, fine particulates, and air toxics; (c) substantially reduce waste and emission control costs; (d) greatly lower capital cost; and (e) considerably reduce steel production costs. This technology is based on the unique capability of microwaves to rapidly heat steelmaking raw materials to elevated temperature, then rapidly reduce iron oxides to metal by volumetric heating. Microwave heating, augmented with electric arc and exothermal reactions, is capable of producing molten steel. This technology has the components necessary to establish the ''future'' domestic steel industry as a technology leader with a strong economically competitive position in world markets. The project goals were to assess the utilization of a new steelmaking technology for its potential to achieve better overall energy efficiency, minimize pollutants and wastes, lower capital and operating costs, and increase the competitiveness of the

  16. THE EFFECT OF NITROGEN GAS FLOW RATE ON THE PROPERTIES OF TiN-COATED HIGH-SPEED STEEL (HSS) USING CATHODIC ARC EVAPORATION PHYSICAL VAPOR DEPOSITION (PVD) TECHNIQUE

    OpenAIRE

    ALI MUBARAK; ESAH BINTI HAMZAH; MOHD RADZI HJ. MOHD TOFF; ABDUL HAKIM BIN HASHIM

    2005-01-01

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation techniq...

  17. Towards laser-manipulated deposition for atom-scale technologies

    International Nuclear Information System (INIS)

    We have developed an apparatus for nanostructure fabrication based on direct deposition of laser-manipulated cesium vapors onto pyrolitic graphite. Key features of our apparatus are production and manipulation of a longitudinally cooled atom beam, which allows for straightforward operation in the moderate to low flux density conditions. Both unstructured and structured low surface coverage depositions have been carried out and samples carefully analyzed at the atom scale by in situ tunneling microscopy. Results represent a step forward to the realization of a novel technology for space-controlled deposition of few, eventually single, atoms.

  18. Nanomechanical properties of TiCN and TiCN/Ti coatings on Ti prepared by Filtered Arc Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yong [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Lu, Cheng, E-mail: chenglu@uow.edu.au [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Yu, Hailiang [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); School of Mechanical Engineering, Shenyang University, Shenyang 110044 (China); Kiet Tieu, A.; Su, Lihong; Zhao, Yue; Zhu, Hongtao [School of Mechanical, Materials & Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Kong, Charlie [Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052 (Australia)

    2015-02-11

    Monolayer TiCN and multilayer TiCN/Ti coatings were deposited on the surface of Ti using the Filtered Arc Deposition System (FADS). Nanoindentation tests were performed on both coatings. The multilayer TiCN/Ti coating exhibited better ductility than the monolayer TiCN coating. The lattice constants of the coatings were characterized by X-ray diffraction. Transmission Electron Microscopy (TEM) was used to investigate the fracture behavior of the coatings. Inter-columnar, inclined and lateral cracks were found to be the dominant crack modes in the monolayer TiCN coatings while small bending crack and radial crack were the dominant crack modes in the multilayer TiCN/Ti coatings. The Finite Element Method (FEM) was used to simulate the indentation process. It was found that the Ti interlayer in the multilayer TiCN/Ti coating could efficiently suppress the fracture, which is responsible for the improved ductility of the multilayer TiCN/Ti coating.

  19. Nanomechanical properties of TiCN and TiCN/Ti coatings on Ti prepared by Filtered Arc Deposition

    International Nuclear Information System (INIS)

    Monolayer TiCN and multilayer TiCN/Ti coatings were deposited on the surface of Ti using the Filtered Arc Deposition System (FADS). Nanoindentation tests were performed on both coatings. The multilayer TiCN/Ti coating exhibited better ductility than the monolayer TiCN coating. The lattice constants of the coatings were characterized by X-ray diffraction. Transmission Electron Microscopy (TEM) was used to investigate the fracture behavior of the coatings. Inter-columnar, inclined and lateral cracks were found to be the dominant crack modes in the monolayer TiCN coatings while small bending crack and radial crack were the dominant crack modes in the multilayer TiCN/Ti coatings. The Finite Element Method (FEM) was used to simulate the indentation process. It was found that the Ti interlayer in the multilayer TiCN/Ti coating could efficiently suppress the fracture, which is responsible for the improved ductility of the multilayer TiCN/Ti coating

  20. LARGE AREA FILTERED ARC DEPOSITION OF CARBON AND BORON BASED HARD COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Rabi S.

    2003-12-05

    This document is a final report covering work performed under Contract No. DE-FG02-99ER82911 from the Department of Energy under a SBIR Phase II Program. Wear resistant, hard coatings can play a vital role in many engineering applications. The primary goal of this project was to develop coatings containing boron and carbon with hardness greater than 30 GPa and evaluate these coatings for machining applications. UES has developed a number of carbon and boron containing coatings with hardness in the range of 34 to 65 GPa using a combination of filtered cathodic arc and magnetron sputtering. The boron containing coatings were based on TiB2, TiBN, and TiBCN, while the carbon containing coatings ere TiC+C and hydrogen free diamond-like-carbon. Machining tests were performed with single and multilayer coated tools. The turning and milling tests were run at TechSolve Inc., under a subcontract at Ohio State University. Significant increases in tool lives were realized in end milling of H-13 die steel (8X) and titanium alloy (80%) using the TiBN coating. A multilayer TiBN/TiN performed the best in end-milling of highly abrasive Al-Si alloys. A 40% increase in life over the TiAlN benchmark coating was found. Further evaluations of these coatings with commercialization partners are currently in progress.

  1. Demonstration of Plasma Arc Environmental Technology Applications for the Demilitarization of DOD Stockpiles

    Science.gov (United States)

    Smith, Ed; Zaghloul, Hany; Filius, Krag; Rivers, Tim

    2000-01-01

    Since 1989 the U.S. Army Construction Engineering Research Laboratories (USACERL) have been active participants in the research and development toward establishing Plasma Arc Technology (PAT) as an efficient, economical, and safe hazardous waste immobilization tool. A plasma torch capable of generating high temperatures makes this technology a viable and powerful tool for the thermal destruction of various military industrial waste streams into an innocuous ceramic material no longer requiring hazardous waste landfill (Class 1) disposal. The emerging pl asma environmental thermal treatment process, has been used to safely and efficiently meet the waste disposal needs for various demilitarized components disposal needs, such as: pyrotechnic smoke assemblies, thermal batteries, proximity fuses, cartridge actuated devices (CAD's), and propellant actuated devices (PAD's). MSE Technology Applications, Inc., (MSE) has proposed and fabricated a Mobile Plasma Treatment System to be a technology demonstrator for pilot-scale mobile plasma waste processing. The system is capable of providing small-scale waste remediation services, and conducting waste stream applicability demonstrations. The Mobile Plasma Treatment System's innovative concept provides the flexibility to treat waste streams at numerous sites and sites with only a limited quantity of waste, yet too hazardous to transport to a regional fixed facility. The system was designed to be operated as skid mounted modules; consisting of a furnace module, controls module, offgas module, and ancillary systems module. All system components have been integrated to be operated from a single control station with both semi-continuous feeding and batch slag-pouring capability.

  2. Demonstration of Plasma Arc Environmental Technology Applications for the Demilitrization of DOD Stockpiles

    Science.gov (United States)

    Smith, Ed; Dee, P. E.; Zaghloul, Hany; Filius, Krag; Rivers, Tim

    2000-01-01

    Since 1989 the US Army Construction Engineering Research Laboratories (USACERL) have been active participants in the research and development towards establishing Plasma Arc Technology (PAT) as an efficient, economical, and safe hazardous waste immobilization tool. A plasma torch capable of generating high temperatures makes this technology a viable and powerful tool for the thermal destruction of various military industrial waste streams into an innocuous ceramic material no longer requiring hazardous waste landfill disposal. The emerging plasma environmental thermal treatment process has been used to safely and efficiently meet the waste disposal needs for various demilitarized components disposal needs, such as: (1) pyrotechnic smoke assemblies, (2) thermal batteries, (3) proximity fuses, (4) cartridge actuated devices (CADs), and (5) propellant actuated devices (PADs). MSE Technology Applications, Inc., (MSE) has proposed and fabricated a Mobile Plasma Treatment System to be a technology demonstrator for pilotscale mobile plasma waste processing. The system is capable of providing small-scale waste remediation services, and conducting waste stream applicability demonstrations. The Mobile Plasma Treatment System's innovative concept provides the flexibility to treat waste streams at numerous sites and sites with only a limited quantity of waste, yet too hazardous to transport to a regional fixed facility. The system was designed to be operated as skid mounted modules; consisting of a furnace module, controls module, offgas module, and ancillary systems module. All system components have been integrated to be operated from a single control station with both semi-continuous feeding and batch slag-pouring capability.

  3. Geochemistry of metalliferous, hydrothermal deposits in the Aeolian arc (Tyrrhenian Sea)

    Science.gov (United States)

    Savelli, C.; Marani, M.; Gamberi, F.

    1999-03-01

    In shallow-water areas of the submerged volcanic complex around the island of Panarea (Aeolian archipelago), hydrothermal precipitation of both low-temperature Fe-oxyhydroxide-rich red muds and crusts, and high-temperature, sediment-hosted massive sulfides was discovered during an integrated, high-resolution survey. Iron-rich crusts were also found on the bathymetric high of Secca del Capo, north of Salina island. The exhalative iron-rich sediments occur in small (closed) depressions or in proximity to faults and scarps at water depths ranging from 55 to 285 m. The principal chemical characteristics of these deposits are high, but variable, Fe content ranging from 12.2 to 45%, and low contents of the transition elements Mn, Cu, Zn, Ni and Co. The low contents of Cu, Ni and Co suggest a hydrothermal origin. The Fe-oxyhydroxide deposits are enriched in light rare earth element (REE) (35-110×chondrite) compared to heavy REE (10-25×chondrite). Their REE patterns are similar to those of associated calc-alkaline volcanics: negative slope of light REE and a horizontal distribution of the heavy ones. This contrasts with the pattern for iron and manganese oxides of hydrogenous origin, which have tilted trends of heavy REE paralleling that of seawater. The mineralogy of the polymetallic sulfide deposits consists of galena, sphalerite, pyrite and barite in the form of silt-sand grains and decimeter-sized fragments disseminated in clay, 30 cm below the seabed, at a waterdepth of 80 m. The chemistry of the Aeolian iron-rich, low-temperature deposits and of the high-temperature, Ba-rich Pb and Zn sulfides suggests that they are genetically analogous to, respectively, the kuroko-type iron formation (`tetsusekiei') and the black ore exposed in the Miocene Hokuroku district of Japan.

  4. Deposition of chromium nitride coatings from vacuum arc plasma in increased nitrogen pressure

    International Nuclear Information System (INIS)

    The application of protective coatings on metal materials is the effective way to improve their durability. Chromium nitride coatings are applied mainly on tools due to good resistivity to oxidation compared to other metal nitride coatings and good wear resistance. Some characteristics of the coatings deposited in fixed position in regard of chromium cathode on the samples parallel directed to it and the other arranged opposite in the nitrogen pressure ranged from 0.5 to 3.0 Pa are investigated.

  5. Coating material innovation in conjunction with optimized deposition technologies

    International Nuclear Information System (INIS)

    Concentrating on physical vapour deposition methods several examples of recently developed coating materials for optical applications were studied for film deposition with optimized coating technologies: mixed evaporation materials for ion assisted deposition with modern plasma ion sources, planar metal and oxide sputter targets for Direct Current (DC) and Mid-Frequency (MF) pulsed sputter deposition and planar and rotatable sputter targets of transparent conductive oxides (TCO) for large-area sputter deposition. Films from specially designed titania based mixed evaporation materials deposited with new plasma ion sources and possible operation with pure oxygen showed extended ranges of the ratio between refractive index and structural film stress, hence there is an increased potential for the reduction of the total coating stress in High-Low alternating stacks and for coating plastics. DC and MF-pulsed sputtering of niobium metal and suboxide targets for optical coatings yielded essential benefits of the suboxide targets in a range of practical coating conditions (for absent in-situ post-oxidation ability): higher refractive index and deposition rate, better reproducibility and easier process control, and the potential for co-deposition of several targets. Technological progress in the manufacture of rotatable indium tin oxide (ITO) targets with regard to higher wall-thickness and density was shown to be reflected in higher material stock and coater up-time, economical deposition rates and stable process behaviour. Both for the rotatable ITO targets and higher-dense aluminum-doped zinc oxide (AZO) planar targets values of film transmittance and resistivity were in the range of the best values industrially achieved for films from the respective planar targets. The results for the rotatable ITO and planar AZO targets point to equally optimized process and film properties for the optimized rotatable AZO targets currently in testing

  6. Research and engineering application of the arc welding pulsed controller technology

    Institute of Scientific and Technical Information of China (English)

    Li Huan; Cui Jia; Niu Yong; Du Naicheng

    2005-01-01

    The tenacity of heat-affected zone (HAZ) will decline and the size of grains will increase, because of the overheating on HAZ when submerged arc welding (SAW) is used to thick plate with high heat input. The shaping will worsen when SAW is used to thin plate with high current at high speed. A new SAW technology, the pulsed direct current (DC)automatic SAW, will be put forward in this paper in order to overcome the above shortcomings. And a pulsed controller with micro-controller unit (MCU) as the core, nixie tube (NT) and keyboard as the man-machine conversation interface is developed. The main functions of the pulsed controller include the output of pulsed welding current and the working with twinwire. The research has widely prospects in application with significant meanings in theory and practical engineering.

  7. Formation of hydrothermal deposits at Kings Triple Junction, northern Lau back-arc basin, SW Pacific: The geochemical perspectives

    Science.gov (United States)

    Paropkari, Anil L.; Ray, Durbar; Balaram, V.; Surya Prakash, L.; Mirza, Imran H.; Satyanarayana, M.; Gnaneshwar Rao, T.; Kaisary, Sujata

    2010-04-01

    An inactive hydrothermal field was discovered near Kings Triple Junction (KTJ) in northern Lau back-arc basin during 19th cruise of R/V Akademik Mstislav Keldysh in 1990. The field consisted of a large elongated basal platform 'the pedestal' with several 'small' chimneys on its periphery and one 'main mound' superposed over it. The surrounding region is carpeted with lava pillows having ferromanganese 'precipitate' as infillings. The adjoining second field consisted of small chimney like growths termed as 'Christmas Tree' Field. The basal pedestal, the peripheral chimneys and small 'Christmas Tree' like growths (samples collected by MIR submersibles), though parts of the same hydrothermal field, differ significantly in their mineralogy and elemental composition indicating different history of formation. The pedestal slab consisting of chalcopyrite and pyrite as major minerals and rich in Cu is likely to have formed at higher temperatures than sphalerite dominated peripheral chimney. Extremely low concentration of high field strength elements (e.g. Zr, Hf, Nb and Ta) and enrichment of light REE in these sulfides indicate prominent influence of aqueous arc-magma, rich in subduction components. The oxide growths in the 'Christmas Tree' Field have two distinct layers, Fe rich orange-red basal part which seems to have formed at very low temperature as precipitates from diffused hydrothermal flows from the seafloor whereas Mn rich black surface coating is formed from hydrothermal fluids emanated from the seafloor during another episode of hydrothermal activity. Perhaps this is for the first time such unique hydrothermal oxide growths are being reported in association with hydrothermal system. Here, we discuss the possible processes responsible for the formation of these different hydrothermal deposits based on their mineralogy and geochemistry.

  8. Thermal conductivity of titanium nitride/titanium aluminum nitride multilayer coatings deposited by lateral rotating cathode arc

    International Nuclear Information System (INIS)

    A series of [TiN/TiAlN]n multilayer coatings with different bilayer numbers n = 5, 10, 25, 50, and 100 were deposited on stainless steel substrate AISI 304 by a lateral rotating cathode arc technique in a flowing nitrogen atmosphere. The composition and microstructure of the coatings have been analyzed by using energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), and conventional and high-resolution transmission electron microscopy (HRTEM). XRD analysis shows that the preferential orientation growth along the (111) direction is reduced in the multilayer coatings. TEM analysis reveals that the grain size of the coatings decreases with increasing bilayer number. HRTEM imaging of the multilayer coatings shows a high density misfit dislocation between the TiN and TiAlN layers. The cross-plane thermal conductivity of the coatings was measured by a pulsed photothermal reflectance technique. With increasing bilayer number, the multilayer coatings' thermal conductivity decreases gradually. This reduction of thermal conductivity can be ascribed to increased phonon scattering due to the disruption of columnar structure, reduced preferential orientation, decreased grain size of the coatings and present misfit dislocations at the interfaces. - Highlights: • TiN/TiAlN multilayer coatings with different bilayer number were deposited on SS. • The composition and microstructure of the as-deposited coatings were analyzed. • Thermal conductivity of the coatings was measured by pulsed photothermal reflectance. • Thermal conductivity depends on the coatings' microstructure and number of layers. • With increasing the bilayer number, thermal conductivity decreased

  9. Thermal conductivity of titanium nitride/titanium aluminum nitride multilayer coatings deposited by lateral rotating cathode arc

    Energy Technology Data Exchange (ETDEWEB)

    Samani, M.K., E-mail: majid1@e.ntu.edu.sg [Novitas, Nanoelectronics Centre of Excellence, School of Electrical & Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Surface Technology Group, Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Ding, X.Z. [Surface Technology Group, Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Khosravian, N. [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Amin-Ahmadi, B. [Electron Microscopy for materials Science (EMAT), Department of Physics, University of Antwerpen, Groenenborgerlan 171, B-2020 Antwerpen (Belgium); Yi, Yang [Data Storage Institute, A*STAR (Agency for Science, Technology and Research), 117608 (Singapore); Chen, G. [BC Photonics Technological Company, 5255 Woodwards Rd., Richmond, BC V7E 1G9 (Canada); Neyts, E.C.; Bogaerts, A. [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Tay, B.K. [Novitas, Nanoelectronics Centre of Excellence, School of Electrical & Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2015-03-02

    A series of [TiN/TiAlN]{sub n} multilayer coatings with different bilayer numbers n = 5, 10, 25, 50, and 100 were deposited on stainless steel substrate AISI 304 by a lateral rotating cathode arc technique in a flowing nitrogen atmosphere. The composition and microstructure of the coatings have been analyzed by using energy dispersive X-ray spectroscopy, X-ray diffraction (XRD), and conventional and high-resolution transmission electron microscopy (HRTEM). XRD analysis shows that the preferential orientation growth along the (111) direction is reduced in the multilayer coatings. TEM analysis reveals that the grain size of the coatings decreases with increasing bilayer number. HRTEM imaging of the multilayer coatings shows a high density misfit dislocation between the TiN and TiAlN layers. The cross-plane thermal conductivity of the coatings was measured by a pulsed photothermal reflectance technique. With increasing bilayer number, the multilayer coatings' thermal conductivity decreases gradually. This reduction of thermal conductivity can be ascribed to increased phonon scattering due to the disruption of columnar structure, reduced preferential orientation, decreased grain size of the coatings and present misfit dislocations at the interfaces. - Highlights: • TiN/TiAlN multilayer coatings with different bilayer number were deposited on SS. • The composition and microstructure of the as-deposited coatings were analyzed. • Thermal conductivity of the coatings was measured by pulsed photothermal reflectance. • Thermal conductivity depends on the coatings' microstructure and number of layers. • With increasing the bilayer number, thermal conductivity decreased.

  10. Factors affecting the hydrogen content of weld metal deposited by flux cored arc welding consumables

    International Nuclear Information System (INIS)

    This paper present the results of an investigation of weld metal diffusible hydrogen levels in a range of flux cored wired suitable for welding of C and C-Mn steels. Both basis and rutile wires have been investigated to assess the effect of the heat input (achieved by altering welding current and traverse speed), the contact-tip to workpiece distance (CTWD), the shielding gas type and the atmospheric exposure of the wires. The main focus of the project is to expand the current knowledge of hydrogen assisted cold cracking (HACC) in flux cored wires. The paper reports the results of diffusible hydrogen levels in single run bead-on-plate welds as a function of welding conditions. This work is a contribution to the aim of defining industrial welding conditions which minimise or eliminate the risk of HACC in weld metal deposited by flux cored wires

  11. Annealing effect of thermal spike in MgO thin film prepared by cathodic vacuum arc deposition

    International Nuclear Information System (INIS)

    MgO films were prepared by using pulsed cathodic vacuum arc deposition technique. The substrate bias voltage was in the range of −150 to −750 V. Film structure was investigated by X-ray diffraction (XRD). The annealing effect of thermal spike produced by the impacting of energetic ions was analyzed. The calculated results showed that the lifetime of a thermal spike generated by an energetic ion with the energy of 150 eV was less than one picosecond and it was sufficient to allow Mg2+ or O2- to move one bond length to satisfy the intrinsic stress relief in the affected volume. The MgO(200) lattice spacings of the films deposited at different bias voltages were all larger than the ideal value of 2.1056 Å. As the bias amplitude increased the lattice spacing decreased, which indicated that the compressive stress in the film was partially relieved with increasing impacting ion energy. The stress relief also could be reflected from the film orientation with bias voltage. The biaxial elastic modulus for MgO(100), MgO(110) and MgO(111) planes were calculated and they were M(100) = 199 GPa, M(110) = 335 GPa and M(111) = 340 GPa, respectively. The M values indicated that the preferred orientation will be MgO(200) due to the minimum energy configuration when the lattice strain was large. It was confirmed by the XRD results in our experiments. - Highlights: • MgO thin films with preferred orientation were obtained by CVAD technique. • Annealing effect of a thermal spike in MgO film was discussed. • Lattice spacing of MgO film decreased with the increase of bias voltage. • Film preferred orientation changed from (200) to (220) as the bias voltage increased

  12. Incidence Angle Effect of Energetic Carbon Ions on Deposition Rate, Topography, and Structure of Ultrathin Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc

    KAUST Repository

    Wang, N.

    2012-07-01

    The effect of the incidence angle of energetic carbon ions on the thickness, topography, and structure of ultrathin amorphous carbon (a-C) films synthesized by filtered cathodic vacuum arc (FCVA) was examined in the context of numerical and experimental results. The thickness of a-C films deposited at different incidence angles was investigated in the light of Monte Carlo simulations, and the calculated depth profiles were compared with those obtained from high-resolution transmission electron microscopy (TEM). The topography and structure of the a-C films were studied by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. The film thickness decreased with the increase of the incidence angle, while the surface roughness increased and the content of tetrahedral carbon hybridization (sp 3) decreased significantly with the increase of the incidence angle above 45° , measured from the surface normal. TEM, AFM, and XPS results indicate that the smoothest and thinnest a-C films with the highest content of sp 3 carbon bonding were produced for an incidence angle of 45°. The findings of this study have direct implications in ultrahigh-density magnetic recording, where ultrathin and smooth a-C films with high sp 3 contents are of critical importance. © 2012 IEEE.

  13. Density changes with substrate negative bias for ta-C films deposited by filter cathode vacuum arc

    Institute of Scientific and Technical Information of China (English)

    TAN Man-lin; ZHU Jia-qi; HAN Jie-cai; MENG Song-he

    2004-01-01

    Specular X-ray reflectivity (XRR) measurements were used to study the density and cross-section information of tetrahedral amorphous carbon (ta-C) films deposited by filter cathode vacuum arc(FCVA) system at different substrate bias. According to the correlation between density and substrate negative bias, it is found that the value of density reaches a maximum at -80 V bias. As the substrate bias increases or decreases, the density tends to lower gradually. Based on the density of diamond and graphite, sp3 bonding ratio of ta-C films was obtained from their corresponding density according to a simple equation between the two. And a similar parabolic variation was observed for ta-C films with the sp3 content changes with substrate negative bias. The mechanical properties such as hardness and elastic modulus were also measured and compared with the corresponding density for ta-C films. From the distribution of data points, a linear proportional correlation between them was found, which shows that the density is a critical parameter to characterize the structure variation for ta-C films.

  14. Oxygen-Plasma-Treated Indium-Tin-Oxide Films on Nonalkali Glass Deposited by Super Density Arc Plasma Ion Plating

    Science.gov (United States)

    Kim, Soo Young; Hong, Kihyon; Son, Jun Ho; Jung, Gwan Ho; Lee, Jong-Lam; Choi, Kyu Han; Song, Kyu Ho; Ahn, Kyung Chul

    2008-02-01

    The effects of O2 plasma treatment on both the chemical composition and work function of an indium-tin-oxide (ITO) film were investigated. ITO films were deposited on non-alkali glass substrate by super density arc plasma ion plating for application in active-matrix organic light-emitting diodes (OLEDs). The water contact angle decreased from 38 to 11° as the ITO films were treated with O2 plasma for 60 s at a plasma power of 150 W, indicating an increase in the hydrophilicity of the surface. It was found that there were no distinct changes in the microstructure or electrical properties of the ITO films with O2 plasma treatment. Synchrotron radiation photoemission spectroscopy data revealed that O2 plasma treatment decreased the amount of carbon contamination and increased the number of unscreened states of In3+ and (O2)2- peroxo species. This played the role of increasing the work function of the ITO films by 1.7 eV. As a result, the turn-on voltage of the OLED decreased markedly from 24 to 8 V and the maximum luminance value of the OLED increased to 2500 cd/m2.

  15. Microstructural and mechanical properties evolutions of plasma transferred arc deposited Norem02 hardfacing alloy at high temperature

    International Nuclear Information System (INIS)

    Highlights: → Norem02 microstructure constituted with austenite, ferrite, M7C3 and MC carbides. → Microstructure after a reheating thermal treatment as a function of temperature. → High temperature and long time are needed to perturb the microstructure. → No phase transformations detected from 20 deg. C up to 1000 deg. C. → Mechanical properties show linear evolution with temperature. - Abstract: Plasma-transferred-arc welded Norem02, an iron-based hard-facing alloy, was characterised. Its microstructure and chemical composition were investigated using optical microscopy, scanning electron microscopy (with electron probe microanalysis), electron backscattering diffraction, and X-ray diffraction. The microstructure of the as-deposit alloy consists of a dendritic austenite structure with ferrite islets at dendrites centres, with an interdendritic eutectic region containing austenite, M7C3 and M23C6 carbides and zones containing Mo-rich precipitates. Tensile behaviour of Norem02 was characterised and completed by dilatometry tests in welding process temperature range. No significant phase transformation was detectable during mechanical testing. Different heat treatment cycles of ageing at high temperatures (until 1100 deg. C) were carried out for different durations. The microstructure of Norem02 heated at 1100 deg. C was not significantly affected by a short time (15 s) treatment whereas changes were observed for longer durations (2 h), although hardness remains almost unchanged. This work tends to demonstrate that for this alloy metallurgical evolution during the welding process has very little influence on mechanical properties.

  16. Mechanical properties and phase structure of (TiAlZr)N films deposited by multi arc ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jun, E-mail: zhjun88@126.co [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China) and State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian 116024 (China); Guo Wenying [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China); Zhang Yu [Department of Physics, Applied Science School, University of Science and Technology Beijing, Beijing, 100083 (China); Guo Qiang; Wang Chuang; Zhang Lipeng [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China)

    2009-07-01

    A series of Ti-Al-Zr alloy targets with the atomic ratio of (Al + Zr)/(Ti + Al + Zr) from 0.29 to 0.40 were used directly to prepare (Ti,Al,Zr)N multi component hard reactive films on high speed steel substrates by multi arc ion plating (MAIP) technology. The surface morphology, the cross-fracture microstructure, the surface compositions and the phase structure of the (Ti,Al,Zr)N films were investigated by scanning electronic microscope (SEM) and X-ray diffraction (XRD). The dense columnar microstructure was obtained in all of the (Ti,Al,Zr)N films, though micro-droplets evidently existed on the surface of the films. The XRD analysis revealed f.c.c. structure only existing in all of the (Ti,Al,Zr)N films. The lattice parameter was changed with varying the Al and Zr contents in alloy targets. The micro-hardness of film surface and the adhesive property of film/substrate were measured. All the (Ti,Al,Zr)N films displayed excellent mechanical properties. The adhesive strength, in terms of critical load, was larger than 100N and the hardness was bigger than 3000Kg(f)/mm{sup 2}. The (Ti,Al,Zr)N film displayed the highest micro-hardness as the atomic ratio of (Al + Zr)/(Ti + Al + Zr) in Ti-Al-Zr alloy target reached 0.40. The present results suggest the expectant substitution of (Ti,Al,Zr)N films for TiN, (Ti,Al)N and (Ti,Zr)N hard films in industrial application and the technical advantage of Ti-Al-Zr alloy targets in preparing (Ti,Al,Zr)N hard films by multi arc ion plating.

  17. New technology developed for optimization of electric arc furnace fume systems

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-06-01

    A new control technology for the optimization of electric arc furnace fume systems has been developed by Goodfellow Technologies Inc. The process, entitled the Expert Furnace System Optimization Process (EFSOP{sup TM)}, uses continuous fume analysis, flow measurement and temperature measurement, as well as real-time process data, to adjust fume system setpoints and operation on a minute-by-minute basis. The system can also be used to control post-combustion systems. EFSOP{sup TM} optimizes furnace combustion and reduces energy costs. The furnace off-gas is analyzed just before the combustion gap in order to quantify the availability of carbon monoxide (CO) in the off-gas as a result of incomplete combustion of oxygen and fuel in the furnace shell. Some furnace practices also result in high levels of hydrogen (H{sub 2}) in the off-gas stream. With EFSOP{sup TM}, CO and H{sub 2} concentrations are decreased at every point in the ventilation system thereby minimizing explosion risks in the system.

  18. Preparation of solid-solution type Fe-Co nanoalloys by synchronous deposition of Fe and Co using dual arc plasma guns.

    Science.gov (United States)

    Sadakiyo, Masaaki; Heima, Minako; Yamamoto, Tomokazu; Matsumura, Syo; Matsuura, Masashi; Sugimoto, Satoshi; Kato, Kenichi; Takata, Masaki; Yamauchi, Miho

    2015-09-28

    We succeeded in the efficient preparation of well-dispersed Fe-Co nanoalloys (NAs) using the arc plasma deposition method. Synchronous shots of dual arc plasma guns were applied to a carbon support to prepare the solid-solution type Fe-Co NAs having an approximately 1 : 1 atomic ratio. The alloy structures with and without a reductive thermal treatment under a hydrogen atmosphere were examined using X-ray powder diffraction, scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray analysis, high resolution STEM, and magnetic measurements, suggesting that highly crystalline spherical particles of ordered B2-type Fe-Co NAs form by the thermal treatment of the deposited grains. PMID:26293826

  19. INVESTIGATION OF SURFACING TECHNOLOGICAL OPPORTUNITIES BY THE INDIRECT THREE-PHASE ARC WITH CONSUMABLE ELECTRODES

    OpenAIRE

    Bezrukih, A.; Meister, R; Lubnin, M.; Gotovko, S.

    2010-01-01

    This paper is devoted to the high-effective process of surfacing by the indirect three-phase arc with covered electrodes. The share of the parent metal in the surfaced one does not exceed 10 % which is infeasible for one-arc surfacing.

  20. Superhard carbon deposited by pulsed high-current arc as protective nanocoating for magnetic hard disks; Superharter Kohlenstoff abgeschieden mit gepulstem Hochstrombogen als Nanoschutzschicht fuer Magnetspeicherplatten

    Energy Technology Data Exchange (ETDEWEB)

    Neuhaeuser, M.; Hilgers, H. [IBM Mainz (Germany). Abt. 4627; Witke, T. [Infenion Dresden (Germany). Bereich PVD; Siemroth, P. [Fraunhofer-Institut fuer Werkstoffphysik und Schichttechnologie (IWS), Dresden (Germany)

    2001-08-01

    Superhard amorphous carbon films (ta-C) deposited by pulsed high-current arc (HCA) possess a good perspective to be used as future ultrathin protective coatings for magnetic hard disks. The ta-C coatings meet all demands concerning the mechanical, chemical and tribological properties required for corrosion and wear protective coatings with thicknesses of 2-3 nm. From the current point of view the deposition technique also qualifies for an industrial mass production. Consequently there is a very good prospect that in near future the high-current arc technique will be the method of choice for carbon deposition in industrial hard disk drive production. (orig.) [German] Superharte amorphe Kohlenstoffschichten (ta-C), die mit gepulstem Hochstrombogen (high-current arc, HCA) abgeschieden werden, besitzen ein hohes Potential als zukuenftige ultraduenne Schutzschichten fuer Magnetspeicherplatten. Die ta-C-Schichten erfuellen alle wesentlichen Anforderungen, die in mechanischer, chemischer und tribologischer Hinsicht an 2-3 nm dicke Verschleiss- und Korrosionsschutzschichten gestellt werden. Auch die Beschichtungstechnik ist aus jetziger Sicht fuer die Massenproduktion geeignet. Damit bestehen sehr gute Aussichten, dass in naher Zukunft die Hochstrombogenverdampfung die Methode der Wahl fuer die Kohlenstoffabscheidung in der industriellen Festplattenproduktion darstellt. (orig.)

  1. The electronic structure of tungsten oxide thin films prepared by pulsed cathodic arc deposition and plasma-assisted pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Pulsed cathodic arc and pulsed magnetron sputtered WO3 thin films were investigated using electron microscopy. It was found that the cathodic arc deposited material consisted of the α-WO3 phase with a high degree of crystallinity. In contrast, the magnetron sputtered material was highly disordered making it difficult to determine its phase. Electron energy-loss spectroscopy was used to study the oxygen K edge of the films and it was found that the near-edge fine structures of films produced by the two deposition methods differed. The oxygen K-edge near-edge structures for various phases of WO3 were calculated using two different self-consistent methods. Each phase was found to exhibit a unique oxygen K edge, which would allow different phases of WO3 to be identified using x-ray absorption spectroscopy or electron energy-loss spectroscopy. Both calculation methods predicted an oxygen K edge for the γ-WO3 phase which compared well to previous x-ray absorption spectra. In addition, a close match was found between the oxygen K edges obtained experimentally from the cathodic arc deposited material and that calculated for the α-WO3 phase

  2. Corrosion durability of nanostructured TiAlYN coatings, deposited by PIII and D method from filtered vacuum-arc cathodic plasma

    International Nuclear Information System (INIS)

    The electrochemical characteristics of nanostructured TiAlYN coatings deposited on 12X18H10T steel substrates are investigated in 3% aqueous solution of NaCl. The coatings were deposited from filtered vacuum-arc plasma by PIII and D method. Measurements of corrosion potentials Ecor and anodic polarization curves showed that the best protection against galvanic corrosion (GC) provides TiA1YN coating containing 0.2 at.% Y deposited on the substrate when applying pulsed bias potential of -1.5 kV amplitude. Addition DC bias potential of -150 V to pulse one leads to deterioration of the protective properties: activation potential of anodic processes (APAP) decreases in 3...4 times. Increase in TiA1YN coatings deposition rate promotes improvement their protective properties due to improved adhesion and decreased level of residual stress

  3. Age and geochemistry of host rocks of the Cobre Panama porphyry Cu-Au deposit, central Panama: Implications for the Paleogene evolution of the Panamanian magmatic arc

    Science.gov (United States)

    Baker, Michael J.; Hollings, Peter; Thompson, Jennifer A.; Thompson, Jay M.; Burge, Colin

    2016-04-01

    The Cobre Panama porphyry Cu-Au deposit, located in the Petaquilla district of central Panama, is hosted by a sequence of medium- to high-K calc-alkaline volcanic and sub-volcanic rocks. New crystallisation ages obtained from a granodiorite Petaquilla batholith and associated mineralised diorite to granodiorite porphyry stocks and dikes at Cobre Panama indicate that the batholith was emplaced as a multi-phase intrusion, over a period of ~ 4 million years from 32.20 ± 0.76 Ma to 28.26 ± 0.61 Ma, while the porphyritic rocks were emplaced over a ~ 2 million year period from 28.96 ± 0.62 Ma to 27.48 ± 0.68 Ma. Both the volcanic to sub-volcanic host rocks and intrusive rocks of the Cobre Panama deposit evolved via fractional crystallisation processes, as demonstrated by the major elements (e.g. Al2O3, Fe2O3, TiO2 and MgO) displaying negative trends with increasing SiO2. The Petaquilla intrusive rocks, including the diorite-granodiorite porphyries and granodiorite batholith, are geochemically evolved and appear to have formed from more hydrous magmas than the preceding host volcanic rocks, as evidenced by the presence of hornblende phenocrysts, higher degrees of large-ion lithophile element (LILE) and light rare earth element (LREE) enrichment and heavy rare earth element (HREE) depletion, and higher Sr/Y and La/Yb values. However, the degree of LREE enrichment, HREE depletion and La/Yb values are insufficient for the intrusive rocks to be considered as adakites. Collectively, the volcanic and intrusive rocks have LILE, REE and mobile trace element concentrations similar to enriched Miocene-age Cordilleran arc magmatism found throughout central and western Panama. Both the Petaquilla and Cordilleran arc magmatic suites are geochemically more evolved than the late Cretaceous to Eocene Chagres-Bayano arc magmas from northeastern Panama, as they display higher degrees of LILE and LREE enrichment. The geochemical similarities between the Petaquilla and Cordilleran arc

  4. Rural power grid resources WebGIS technology research based on ArcIMS

    Institute of Scientific and Technical Information of China (English)

    BAO Qing-peng; ZHANG Xu; SU Zhong-bin; ZHU Jia-mei

    2016-01-01

    WebGIS is a tendency of current geographical information system. ArclMS is an excellent platform to construct WebGIS. This paper introduces the architecture,features and advantages of ArcIMS,which also builds a rural power resources information system based on ArcIMS.This system is a security assurance of reactive power optimization of distribution network,is an effective method of economic operation and is one of important measures to improve the voltage quality of distribution network. Applying ArcSDE to establish spatial database and transform the format of spatial data are key to realizing the system.

  5. Research on Helicopter-borne MIMO Microwave Imaging Technology Based on Arc Antenna Array

    Directory of Open Access Journals (Sweden)

    Huang Ping-ping

    2015-02-01

    Full Text Available This study proposes a novel Multiple Input Multiple Output (MIMO microwave imaging mode based on arc antenna array, which is mounted on the belly of platform. In this mode, an arc aperture is quickly synthesized using an MIMO. Consequently, high space and time resolution images of the illuminated scene around the platform are acquired. First, an imaging principle model based on arc antenna array is described, and its signal model is developed. Then, an imaging algorithm based on confocal projection is discussed and the performance of the mode is analyzed. Finally, the feasibility of the imaging mode and the validity of the proposed algorithm are demonstrated with a numerical simulation.

  6. Structural evolution of Ti destroyable interlayer in large-size diamond film deposition by DC arc plasma jet

    Science.gov (United States)

    Guo, Jianchao; Li, Chengming; Liu, Jinlong; Wei, Junjun; Chen, Liangxian; Hua, Chenyi; Yan, Xiongbo

    2016-05-01

    The addition of titanium (Ti) interlayer was verified to reduce the residual stress of diamond films by self-fracturing and facilitate the harvest of a crack-free free-standing diamond film prepared by direct current (DC) arc plasma jet. In this study, the evolution of the Ti interlayer between large-area diamond film and substrate was studied and modeled in detail. The evolution of the interlayer was found to be relevant to the distribution of the DC arc plasma, which can be divided into three areas (arc center, arc main, and arc edge). The formation rate of titanium carbide (TiC) in the arc main was faster than in the other two areas and resulted in the preferred generation of crack in the diamond film in the arc main during cooling. Sandwich structures were formed along with the growth of TiC until the complete transformation of the Ti interlayer. The interlayer released stress via self-fracture. Avoiding uneven fragile regions that formed locally in the interlayer and achieving cooperatively released stress are crucial for the preparation of large crack-free diamond films.

  7. Latest innovations in large area web coating technology via plasma enhanced chemical vapor deposition source technology

    International Nuclear Information System (INIS)

    In this article, the authors discuss the latest results of our development of large area plasma enhanced chemical vapor deposition (PECVD) source technologies for flexible substrates. A significant challenge is the economical application of thin films for use as vapor barriers, transparent conductive oxides, and optical interference thin films. Here at General Plasma the authors have developed two innovative PECVD source technologies that provide an economical alternative to low temperature sputtering technologies and enable some thin film materials not accessible by sputtering. The Penning Discharge Plasma (PDP trade mark sign ) source is designed for high rate direct PECVD deposition on insulating, temperature sensitive web [J. Modocks, Proceedings of the Society of Vacuum Coaters, 2003 (unpublished), p. 187]. This technology has been utilized to deposit SiO2 and SiC:H for barrier applications [V. Shamamian et al. Proceedings of the Flexible Displays and Manufacturing Conferrence, 2006 (unpublished)]. The Plasma Beam Source (PBS trade mark sign ) is a remote plasma source that is more versatile for deposition on not only insulating flexible substrates but also conductive or rigid substrates for deposition of thin films that are sensitive to the high ion bombardment flux inherent to the PDP trade mark sign technology. The authors have developed PBS thin film processes in our laboratory for deposition of SiO2, SiC:O, SiN:C, SiN:H, ZnO, FeOx, and Al2O3. [M. A. George, Conference Proceedings of the Association of Industrial Metallizers, Coaters, and Laminators (AIMCAL), 2007 (unpublished)]. The authors discuss the design of the patented sources, plasma physics, and chemistry of the deposited thin films.

  8. Deposition of thin layers of boron nitrides and hydrogenated microcrystalline silicon assisted by high current direct current arc plasma; Deposition assistee par un plasma a arc a haut courant continu de couches minces de Nitrure de Bore et de Silicium microcristallin hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Franz, D. [Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland)

    1999-09-01

    In the frame of this thesis, a high current direct current arc (HCDCA) used for the industrial deposition of diamond, has been adapted to study the deposition of two types of coatings: a) boron nitride, whose cubic phase is similar to diamond, for tribological applications, b) hydrogenated microcrystalline silicon, for applications in the semiconductor fields (flat panel displays, solar cells,...). For the deposition of these coatings, the substrates were placed in the diffusion region of the arc. The substrate heating is mainly due to atomic species recombining on its surface. The deposition temperature, varying from 300 to 900 {sup o}C according to the films deposited, is determined by the substrate position, the arc power and the injected gas fluxes, without the use of any external heating or cooling system. Measurements performed on the arc plasma show that the electronic temperature is around 2 eV (23'000 K) while the gas temperature is lower than 5500 K. Typical electronic densities are in the range of 10{sup 12}-10{sup 1'}3 cm{sup -3}. For the deposition of boron nitride films, different boron precursors were used and a wide parameter range was investigated. The extreme difficulty of synthesising cubic boron nitride films by chemical vapour deposition (CVD) did not allow to stabilize the cubic phase of boron nitride in HCDCA. Coatings resulted in hexagonal or amorphous boron nitride with a chemical composition close to stoichiometric. The presence of hydrogen leads to the deposition of rough and porous films. Negative biasing of the samples, for positive ion bombardment, is commonly used to stabilize the cubic phase. In HCDCA and in our biasing range, only a densification of the films could be observed. A boron nitride deposition plasma study by infrared absorption spectroscopy in a capacitive radio frequency reactor has demonstrated the usefulness of this diagnostic for the understanding of the various chemical reactions which occur in this kind

  9. Effect of deposition parameters on mechanical properties of TiN films coated on 2A12 aluminum alloys by arc ion plating (AIP)

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2005-01-01

    TiN films were deposited on 2A12 aluminum alloy by arc ion plating (AIP). The Vickers hardness of the films deposited at different bias voltages and different nitrogen gas pressures, and that of the substrate were measured. The surface roughness of the TiN films diposited at -30 V and -80 V respectively and at different nitrogen gas pressure was measured also. The mass loss of TiN films deposited at 0 V, -30 V and -80 V respectively were analyzed in dry sand rubber wheel abrasive wear tests and wet ones in comparison with uncoated Al alloy and austenitic stainless steel (AISI 316L). It is revealed that the highest hardness of the TiN film is obtained at a bias voltage of -30 V and a N2 gas pressure of 0.5 Pa. The surface roughness of the film is larger at -80 V than that at -30 V and reduces as the increase of the N2 gas pressure. The mass loss of TiN-film coated 2A12 aluminum alloy is remarkably less than that of uncoated Al alloy and also that of AISI 316L, which indicates that the abrasive wear rate is greatly reduced by the application of TiN coating. TiN coating deposited by arc ion plating (AIP) technique on aluminum alloy can be a potential coating for machine parts requiring preciseness and lightness.

  10. Development of surface decontamination technology for radioactive waste using plasma. Fundamental investigation of the removal of non-radioactive corrosion products using a low-pressure arc

    International Nuclear Information System (INIS)

    Surface treatment technology using a low-pressure arc (LPA) has attracted considerable attention because it does not require abrasives, as required for existing abrasion methods. The technology allows removal of radionuclides present on or inside the oxide film found on the surface of radioactive metal wastes along with the oxide film itself. In this report we applied a low-pressure arc to the non-radioactive corrosion products formed on a metallic surface under conditions simulating a primary water-cooling line and mill scale on carbon steel. Our results demonstrated clearly that these oxide films could be removed by low-pressure arc. We concluded that surface decontamination technology using a low-pressure arc has potential use for some radioactive wastes generated by atomic power plants. Fundamental data acquired here will help to optimize treatment using this technology. (author)

  11. The influence of nitrogen pressure on the structure of condensates, obtained at vacuum-arc deposition from high entropy alloy AlCrTiZrNbY

    International Nuclear Information System (INIS)

    The possibilities of structural engineering of vacuum-arc coatings based on the high entropy alloy AlCrTiZrNbY have been studied by means of electron microscopy with energy dispersion element analysis, X-ray diffractometry and microidentation methods. It was found, that the coatings formed by means of vacuum-arc method are two-phase objects. The change of nitrogen pressure from 2.0 centre dot 10-4 to 5.0 centre dot 10-4 Torr during the deposition increases the contents of its atoms in the condensate from 2.7 to 21.62%, and this is accompanied by the transfer from nanocrystallic and claster to nanocrystallic two phase state (combination of bcc and fcc structures) and leads to hardness increase from 6.7 to 7.6 GPa. The observed structure changes are explained by the formation of defects of packaging in fcc crystal lattice at low nitrogen content.

  12. Diagnosis of gas phase near the substrate surface in diamond film deposition by high-power DC arc plasma jet CVD

    Institute of Scientific and Technical Information of China (English)

    Zuyuan Zhou; Guangchao Chen; Bin Li; Weizhong Tang; Fanxiu Lv

    2007-01-01

    Optical emission spectroscopy (OES) was used to study the gas phase composition near the substrate surface during diamond deposition by high-power DC arc plasma jet chemical vapor deposition (CVD). C2 radical was determined as the main carbon radical in this plasma atmosphere. The deposition parameters, such as substrate temperature, anode-substrate distance, methane concentration, and gas flow rate, were inspected to find out the influence on the gas phase. A strong dependence of the concentrations and distribution of radicals on substrate temperature was confirmed by the design of experiments (DOE). An explanation for this dependence could be that radicals near the substrate surface may have additional ionization or dissociation and also have recombination,or are consumed on the substrate surface where chemical reactions occur.

  13. Technology validation of coatings deposition onto the brass substrate

    Directory of Open Access Journals (Sweden)

    A.D. Dobrzańska-Danikiewicz

    2010-11-01

    Full Text Available Purpose: The purpose of this article is to evaluate strategic development perspectives of manufacturing metallic-ceramic coatings in the process of physical vapor deposition (PVD on the CuZn40Pb2 brass substrate. The amount of layers applied to the substrate was adopted as the criterion for technology division, thus obtaining three technology groups for foresight researches.Design/methodology/approach: The carried out foresight-materials science researches included creating a dendrological matrix of technology value, a meteorological matrix of environment influence, a matrix of strategies for technologies, laying out strategic development tracks, carrying out materials science experiments which test the mechanical and tribological properties and the resistance to corrosion and erosion of brass covered with a varied number of layers applied using the method of reactive magnetron evaporation, as well as preparing technology roadmaps.Findings: High potential and attractiveness were shown of the analyzed technologies against the environment, as well as a promising improvement of mechanical and tribological properties and an increase of resistance to material corrosion and erosion as a result of covering with PVD coatings.Research limitations/implications: Researches pertaining to covering the brass substrate with PVD coatings is part of a bigger research project aimed at selecting, researching and characterizing priority innovative material surface engineering technologies.Practical implications: The presented results of experimental materials science researches prove the significant positive impact of covering with PVD coatings on the structure and mechanical properties, as well as the resistance to corrosion, erosion and abrasive wear of brass which leads to the justification of their including into the set of priority innovative technologies recommended for application in industrial practice, including in small and medium-size companies

  14. Cr{sub 1-x}Al{sub x}N coatings deposited by lateral rotating cathode arc for high speed machining applications

    Energy Technology Data Exchange (ETDEWEB)

    Ding Xingzhao [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore)], E-mail: xzding@SIMTech.a-star.edu.sg; Zeng, X.T.; Liu, Y.C.; Fang, F.Z.; Lim, G.C. [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore)

    2008-02-29

    In this work, a series of Cr{sub 1-x}Al{sub x}N (0 {<=} x {<=} 0.7) coatings were deposited on high speed steel substrates by a vacuum arc reactive deposition process from two lateral rotating elemental chromium and aluminum cathodes in a flowing pure nitrogen atmosphere. The composition, structural, mechanical, and tribological properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and ball-on-disc tribometer experiments. All of the as-deposited CrAlN coatings exhibited a higher hardness than CrN, showing a maximum hardness of about 40 GPa (at around X = 0.63) which is twice higher than that of the CrN. The wear performance under ambient conditions of the CrAlN coatings was found much better, with both lower friction coefficient and wear rate, than TiAlN coatings deposited by the same technique. The wear rate of the CrAlN coatings against alumina counterpart was about 2-3 orders in magnitude lower than that of the TiAlN coatings. Selected CrAlN coatings with the highest hardness were also deposited on some WC-based end-mills. An evident better performance of the CrAlN-coated end-mills was observed than the TiAlN-coated ones for cutting a hardened tool steel material under high speed machining conditions.

  15. Fabrication of ceramic coatings on NIFS-HEAT by arc-source plasma-assisted deposition method for fusion blanket application

    International Nuclear Information System (INIS)

    Al2O3 coatings and AlN coatings were fabricated by filtered arc-source plasma assisted deposition method on a low activation vanadium alloy NIFS-HEAT-2' for self-cooled liquid blanket application. The AlN coating had a low electrical resistivity due to relatively large amount of Al deposited in the coatings than that of N. Al2O3 bulk specimens and the Al2O3 coating were sintered in Li20-Sn80 and Flibe. They showed a high compatibility in the Li20-Sn80 at 823 K for 1 day. In the Flibe at 823 K for 2 days, on the contrast, slight mass decreases of the bulk specimens were observed and the coatings disappeared. (author)

  16. Development of data processing system for regional geophysical and geochemical exploration of sandstone-hosted uranium deposits based on ArcGIS Engine

    International Nuclear Information System (INIS)

    According to the data processing need of geophysical and geochemical exploration of sandstone-hosted uranium deposits, the function design of the regional geophysical and geochemical data processing system is completed in the paper. The geophysical and geochemical data processing software with powerful functions is also developed based on ArcGIS Engine which remedies the shortage of GIS software for performing the geophysical and geochemical data processing. The development technique route of system software and key techniques are introduced, and the development processes of system software are showed through some development examples. Application practices indicate that the interface of developed system software with friendly interface and utility functions, may quickly perform the data processing of regional geophysical and geochemical exploration and provide the helpful deep information for predicting metallogenic prospective areas of sandstone-hosted uranium deposits. The system software is of a great application foreground. (authors)

  17. Duplex Al2O3/DLC Coating on 15SiCp/2024 Aluminum Matrix Composite Using Combined Microarc Oxidation and Filtered Cathodic Vacuum Arc Deposition

    Science.gov (United States)

    Xue, Wenbin; Tian, Hua; Du, Jiancheng; Hua, Ming; Zhang, Xu; Li, Yongliang

    2012-08-01

    Microarc oxidation (MAO) treatment produces a thick Al2O3 coating on the 15SiCp/2024 aluminum matrix composite. After pretreatment of Ti ion implantation, a thin diamond-like carbon film (DLC) was deposited on the top of polished Al2O3 coating by a pulsed filtered cathodic vacuum arc (FCVA) deposition system with a metal vapor vacuum arc (MEVVA) source. The morphology and tribological properties of the duplex Al2O3/DLC multiplayer coating were investigated by Raman spectroscopy, scanning electron microscopy (SEM) and SRV ball-on-disk friction tester. It is found that the duplex Al2O3/DLC coating had good adhesion and a low friction coefficient of less than 0.07. As compared to a single Al2O3 or DLC coating, the duplex Al2O3/DLC coating on aluminum matrix composite exhibited a better wear resistance against ZrO2 ball under dry sliding, because the Al2O3 coating as an intermediate layer improved load support for the top DLC coating on 15SiCp/2024 composite substrate, meanwhile the top DLC coating displayed low friction coefficient.

  18. Electrical, optical, and structural properties of thin films with tri-layers of AZO/ZnMgO/AZO grown by filtered vacuum arc deposition

    International Nuclear Information System (INIS)

    Highlights: ► AZO/ZnMgO/AZO tri-layered films were grown by FCAD filtered cathodic arc deposition. ► The films were highly transparent and presented excellent electrical resistivity. ► The films presented optical transmittance in the visible light higher than 80%. - Abstract: Transparent conductive oxides (TCO) are indispensable as front electrode for most of thin film electronic devices such as transparent electrodes for flat panel displays, photovoltaic cells, windshield defrosters, transparent thin film transistors, and low emissivity windows. Thin films of aluminum-doped zinc oxide (AZO) have shown to be one of the most promising TCOs. In this study, three layered Al-doped ZnO (AZO)/ZnMgO/AZO heterostructures were prepared by filtered cathodic arc deposition (FCAD) on glass substrates. The objective is to find a set of parameters that will allow for improved optical and electrical properties of the films such as low resistivity, high mobility, high number of charge carriers, and high transmittance. We have investigated the effect of modifications in thickness and doping of the ZnMgO inner layer on the structural, electrical, and optical characteristics of the stacked heterostructures.

  19. Experience and Applications Up-date: Automation of Arc-Welding Operations Using Robot-Technology

    International Nuclear Information System (INIS)

    In a short introduction, the important criteria for the correct choice of a robot cell, taking into account the given application, are highlighted. Furthermore, important hints are listed in terms of management decisions. The second chapter shows the main features of a welding robot cell in line with the present state of the art and describes some new developments with the aim of extending the arc-welding system to new applications such as flame cutting and beveling. The third chapter as centre piece gives an overall view of a brand new network control with many outstanding features for the users of arc-welding robots. the fourth and last chapter shows a recent realisation of a highly sophisticated F.M.S. system for welding, in random sequence, different large and heavy components. (Author) 1 ref

  20. Deposition of silicon-carbon coatings from the plasma of a non-self-sustained arc discharge with a heated cathode

    Science.gov (United States)

    Grenadyorov, A. S.; Oskomov, K. V.; Solov'ev, A. A.; Rabotkin, S. V.

    2016-05-01

    Amorphous hydrogenated carbon doped with silicon oxide ( a-C:H:Si:O), which is referred to as silicon-carbon coatings in this work, consists of thin amorphous films, which are used as commercial solid lubricants due to their higher stability under extreme environmental conditions as compared to amorphous hydrogenated carbon. The deposition of silicon-carbon coatings from the plasma of a non-self-sustained arc discharge with a heated cathode is considered. Silicon-carbon coatings are deposited using polyphenul methylsiloxane as a precursor at a flow rate of 0.05 mL/min in an argon atmosphere at a pressure of 0.1 Pa. A high-frequency power supply is used to apply a high-frequency bias voltage to a substrate during deposition. After deposition, the mechanical properties of the coatings are studied. The maximum hardness of the coating is 20 GPa at a minimum friction coefficient of 0.16 and a wear rate of 1.3 × 10-5 mm3 N-1 m-1. Energy dispersive analysis shows that the coatings contain a significant content of carbon and oxygen (about 80 and 15%, respectively) and a low content of silicon (about 5%).

  1. Effect of pressure on the deposition of hydrogen-free amorphous carbon and carbon nitride films by the pulsed cathodic arc discharge method

    International Nuclear Information System (INIS)

    Hydrogen-free amorphous carbon (a-C) and carbon nitride (a-C:N) films were deposited using the pulsed cathodic arc discharge at different argon and nitrogen pressures. The surface and mechanical properties of these films were found to strongly depend on the gas pressure. The tetrahedral amorphous carbon and hard a-C:N films with smooth surfaces (rms roughness: 0.15 nm) were prepared at lower gas pressures (-2 Pa). Incorporation of an increasing amount of nitrogen in a-C:N films caused a decrease in film hardness. All the films were covered with the thin (0.3-2 nm) graphite-like surface layers. The film hardness was correlated to the soft surface layer thickness, and the films with thinner surface layers exhibit higher hardness. The mean energies of pulsed plasma beams were measured as the functions of argon and nitrogen pressures. The mean energies of plasma beams decrease in an exponential fashion with increasing gas pressure due to the carbon ion collisions with the neutral gas species. The effects of mean energies of deposited species on the film deposition were explained in terms of the thermal spike migration of surface atoms. The formation of graphite-like surface layers is associated with the low-energy deposition process. The low-energy (10 eV) species may produce the strong thermal spike at film surface, and contribute to the formation of sp3 bonded structure at a sp3 bonded matrix

  2. Development of a plasma-arc-cutting technology like a mechanical saw for atmosphere and under water for dismantling nuclear components of greater thickness

    International Nuclear Information System (INIS)

    Status of research: With the plasma arc cutting it is until now not possible to cut steel under water which is thicker than 100 mm. In a depth of water of 20 m it is only possible to cut steel up to 80 mm. This is not enough for the dismantling technology. Aim of research work: Plasma arc cutting technology should be developed to enable cutting a plate independent of its thickness. Method of research: A plasma-arc-saw has been developed for a thermal cutting of materials, similar to a mechanical saw. To develop and optimize the special nozzles of the plasma-arc-saw the submerged combustion burner has been developed parallel by the arc-saw. Results: There are no problems of thermal cutting a steel independent of its thickness. The thickness of the plate depends only on the diameter of the saw disc. The water depth of 20 m reduced the cutting speed of 10%. The plasma-arc-saw enables thermal cutting of a plate independent of its thickness in a water depth of 20 m without requiring a force. The remote controlled dismantling of a reactor vessel and other components with greater wall thickness is possible. (orig./HP) With 21 refs., 6 tabs., 87 figs

  3. Bioinspired peptide nanotubes: deposition technology, basic physics and nanotechnology applications.

    Science.gov (United States)

    Rosenman, G; Beker, P; Koren, I; Yevnin, M; Bank-Srour, B; Mishina, E; Semin, S

    2011-02-01

    Synthetic peptide monomers can self-assemble into PNM such as nanotubes, nanospheres, hydrogels, etc. which represent a novel class of nanomaterials. Molecular recognition processes lead to the formation of supramolecular PNM ensembles containing crystalline building blocks. Such low-dimensional highly ordered regions create a new physical situation and provide unique physical properties based on electron-hole QC phenomena. In the case of asymmetrical crystalline structure, basic physical phenomena such as linear electro-optic, piezoelectric, and nonlinear optical effects, described by tensors of the odd rank, should be explored. Some of the PNM crystalline structures permit the existence of spontaneous electrical polarization and observation of ferroelectricity. The PNM crystalline arrangement creates highly porous nanotubes when various residues are packed into structural network with specific wettability and electrochemical properties. We report in this review on a wide research of PNM intrinsic physical properties, their electronic and optical properties related to QC effect, unique SHG, piezoelectricity and ferroelectric spontaneous polarization observed in PNT due to their asymmetric structure. We also describe PNM wettability phenomenon based on their nanoporous structure and its influence on electrochemical properties in PNM. The new bottom-up large scale technology of PNT physical vapor deposition and patterning combined with found physical effects at nanoscale, developed by us, opens the avenue for emerging nanotechnology applications of PNM in novel fields of nanophotonics, nanopiezotronics and energy storage devices. PMID:21234978

  4. Hydrogen absorption by Zr-1Nb alloy with TiN[x] film deposited by filtered cathodic vacuum arc

    OpenAIRE

    Kashkarov, Egor Borisovich; Nikitenkov, Nikolai Nikolaevich; Syrtanov, Maksim Sergeevich; Babihina, M. N.

    2016-01-01

    This paper describes the opportunity of titanium nitride (TiNx) films application as protective coating for Zr-2.5Nb alloy from hydrogenation. Dense TiN[x] films were prepared by filtered cathodic vacuum arc (CVA). Hydrogen absorption rate was calculated from the kinetic curves of hydrogen sorption at elevated temperature of the sample (T=673 K) and pressure (P=2 atm). Results revealed that TiN[x] films significantly reduced hydrogen absorption rate of Zr-2.5Nb.

  5. ADHESION STRENGTH OF TiN COATINGS AT VARIOUS ION ETCHING DEPOSITED ON TOOL STEELS USING CATHODIC ARC PVD TECHNIQUE

    OpenAIRE

    MUBARAK ALI; ESAH HAMZAH; NOUMAN ALI

    2009-01-01

    Titanium nitride (TiN) widely used as hard coating material was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The goal of this study was to examine the effect of ion etching with and without titanium (Ti) and chromium (Cr) on the adhesion strength of TiN coatings deposited on tool steels. From the scratch tester, it was observed that by increasing Ti ion etching showed an increase in adhesion strength of the deposited coatings. ...

  6. Resistance to cyclic oxidation of Al-Si diffusion coatings deposited by Arc-PVD on TiAlCrNb alloy

    International Nuclear Information System (INIS)

    One of the candidates to replace superalloys in some engine applications is γ-(TiAl) which is characterized by a density almost half of that of superalloys. Titanium aluminides exhibit a strong TiO2 forming tendency rather than formation of the protective Al2O3 at high temperatures. The oxidation resistance is further reduced with decreasing Al content. The article presents research results of cyclic oxidation of γ-(TiAl) alloy with Al-Si coatings and without coatings. Protective coatings were deposited by Arc-PVD method in two steps. In the first one AlSi layer was deposited. In the second step the temperature of samples in vacuum chamber was increased and diffusion Ti AlSi coating was formed. After coating deposition the heat treatment of samples in vacuum was made. The temperature of heat treatment was 950 oC and the time 2 hours. At temperature of 950 oC cyclic oxidation tests were carried out. The time of reaching the temperature and cooling was 5 minutes. Mass changes of the specimens were recorded every 100 cycles. The total number of cycles amounted to 2400. Phase composition, morphology and the distribution of elements were defined by EDX, XRD and SEM in AlSi layers as well as in the scale. (author)

  7. Study of the phase composition of silicide coatings, based on layered Nb-Mo structures, obtained by vacuum-arc deposition

    Science.gov (United States)

    Lozovan, A. A.; Betsofen, S. Ya; Lenkovets, A. S.

    2016-07-01

    A multilayer composite ∼1000 μm in thickness, formed by niobium and molybdenum layers (number of layers n = 230), is obtained by vacuum-arc deposition with subsequent siliconization of the surface layers at a temperature of 1200 °C. Layer-by-layer phase analysis is performed by X-ray diffraction and scanning electron microscopy. It is found that in the surface layers ∼130 μm in thickness, single-phase silicides (Nb x Mo1- x )Si2 are formed with the hexagonal C40 structure (Strukturbericht designations). Alternating layers of solid solutions based on niobium and molybdenum with a body-centered cubic (BCC) lattice are observed within the composite. The formation of solid solutions caused by heating of the coating leads to convergence of the values of the linear thermal expansion coefficient and Young's modulus at the interface between the layers.

  8. Effect of arc spraying power on the microstructure and mechanical properties of Zn-Al coating deposited onto carbon fiber reinforced epoxy composites

    International Nuclear Information System (INIS)

    This paper investigates the effect of arc spraying power on the microstructure and mechanical properties of Zn-Al coatings deposited on carbon fiber reinforced epoxy composites (CFRE composites). The bond strength between the Zn-Al coatings and the substrates was tested on a RGD-5 tensile testing machine. The microstructures and phase composition of the as-sprayed coatings were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results showed that both the melting extent of Zn-Al particles and the bond strength of the coatings were evidently improved by increasing the spraying power. Moreover, the content of crystalline Zn-Al coatings was slightly changed. Observation of fracture surfaces showed that the Zn-Al coatings could bond well with the carbon fiber bundles using 40 kW spraying power.

  9. Time-Resolved Spectroscopic Observation of Deposition Processes of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films by Using a Coaxial Arc Plasma Gun

    Science.gov (United States)

    Hanada, Kenji; Yoshitake, Tsuyoshi; Nishiyama, Takashi; Nagayama, Kunihito

    2010-08-01

    The deposition of ultrananocrystalline diamond (UNCD)/amorphous carbon composite films using a coaxial arc plasma gun in vacuum and, for comparison, in a 53.3 Pa hydrogen atmosphere was spectroscopically observed using a high-speed camera equipped with narrow-band-pass filters. UNCD crystallites with diameters of approximately 1.6 nm were formed even in vacuum. These extremely small crystallites imply that the formation is predominantly due to nucleation without the subsequent growth. Even in vacuum, emissions from C+ ions, C atoms, and C2 dimers lasted for approximately 100 µs, although the emission lifetimes of these species are generally 10 ns. We consider that the nucleation is due to the supersaturated environment containing excited carbon species with large number densities.

  10. Structure and Performance of TiC-containing Diamond-like Carbon Nanocomposite Coatings Deposited by Rectangular Cathodic Arc Ion-plating

    Institute of Scientific and Technical Information of China (English)

    XIE Guosheng; YIN Zhimin; DING Hui; LI Xiaohong; YANG Bing

    2009-01-01

    TiC-containing diamond-like carbon(TiC-DLC)nanocomposite coatings were deposited by a rectangular cathodic arc ion-plating system using C_2H_2 as reacting gas.Raman spectroscopy and transmission electron microscopy analysis show that with increasing flow rate of C_2H_2,the structure of nanocomposite coatings changes from TiC nanograin-containing to graphite nanograin-containing DLC.The hardness measurements show that the hardness decreases from 28 GPa to 18 GPa with increasing C_2H_2 flow rate.The scratch test show that a high critical load(>40 N)was obtained and exhibited a good adhesion between the coating and the substrate.Wear experiment shows that the friction coefficient of TiC-DLC nanocomposite coatings decreases with increasing C_2H_2.A low friction coefficient of 0.07 was obtained at 480 sccm C_2H_2.

  11. Effect of partial pressure of reactive gas on chromium nitride and chromium oxide deposited by arc ion plating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-sheng; FENG Chang-jie; WANG Fu-hui

    2006-01-01

    The effects of reactive gas partial pressure on droplet formation,deposition rate and change of preferred orientation of CrN and Cr2O3 coatings were studied. For CrN coatings,as nitrogen partial pressure increases,the number and size of droplets increases,the deposition rate initially increases obviously and then slowly,and the preferred orientation of CrN changes from high-index plane to low-index one. For Cr2O3 coatings,with the increase of oxygen partial pressure,the number and size of droplets decreases,the deposition rate decreases and the (300) becomes the preferred orientation. These differences are ascribed to the formation of CrN (with a lower melting point) and Cr2O3 (with a higher melting point) on the surface of Cr target during the deposition of CrN and Cr2O3. Complete coatings CrN or Cr2O3 film can be formed when reactive gas partial pressure gets up to 0.1 Pa. The optimized N2 partial pressure for CrN deposition is about 0.1-0.2 Pa in order to suppress the formation of droplets and the suitable O2 partial pressure for Cr2O3 deposition is approximately 0.1 Pa for the attempt to prevent the peel of the coating.

  12. In Vitro Analysis of Electrophoretic Deposited Fluoridated Hydroxyapatite Coating on Micro-arc Oxidized AZ91 Magnesium Alloy for Biomaterials Applications

    Science.gov (United States)

    Razavi, Mehdi; Fathi, Mohammadhossein; Savabi, Omid; Vashaee, Daryoosh; Tayebi, Lobat

    2015-03-01

    Magnesium (Mg) alloys have been recently introduced as a biodegradable implant for orthopedic applications. However, their fast corrosion, low bioactivity, and mechanical integrity have limited their clinical applications. The main aim of this research was to improve such properties of the AZ91 Mg alloy through surface modifications. For this purpose, nanostructured fluoridated hydroxyapatite (FHA) was coated on AZ91 Mg alloy by micro-arc oxidation and electrophoretic deposition method. The coated alloy was characterized through scanning electron microscopy, transmission electron microscopy, X-ray diffraction, in vitro corrosion tests, mechanical tests, and cytocompatibility evaluation. The results confirmed the improvement of the corrosion resistance, in vitro bioactivity, mechanical integrity, and the cytocompatibility of the coated Mg alloy. Therefore, the nanostructured FHA coating can offer a promising way to improve the properties of the Mg alloy for orthopedic applications.

  13. Development of a plasma-arc-cutting technology like a mechanical saw for dismantling nuclear components of greater thickness under water

    International Nuclear Information System (INIS)

    1. Status of research: Cutting steel with the plasma-arc-saw (saw disk diameter 600 mm) with a thickness up to 100 mm is possible. The cutting process works discontinuously. For the ignition of the special constructed plasma torches it is necessary to stop the rotation of the saw disk so the cutting process works discontinuously. 2. Aim of research work: Plasma arc cutting technology should be developed to enable cutting component parts continuous and computer aided. 3. Method of research: Cutting results of the plasma-arc-saw (saw disk diameter 600 mm) gives design data for the construction of a plasma arc saw with a diameter of 850 mm and a diameter of 1000 mm. To develop and optimize the special nozzles of the plasma-arc-saw experiments with the submerged combustion burner have been performed. 4. Results: There are no problems of thermal cutting a plate of steel and a heat exchanger up to a thickness of 300 mm. The cuttable sheet thickness only depends on the diameter of the saw blade. The emission of dust and aerosol only depends on the melted material. Computer aided cutting is possible. 5. The plasma-arc-saw enables thermal cutting of component parts independent of their thickness in a water depth of 20 m without requiring a force. The remote control dismantling of a reactor vessel and other components with greater wall thickness is possible. (orig.) With 34 refs., 2 tabs., 101 figs

  14. Structural and Physical Characteristics of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Deposited Using a Coaxial Arc Plasma Gun

    Science.gov (United States)

    Yoshitake, Tsuyoshi; Nakagawa, You; Nagano, Akira; Ohtani, Ryota; Setoyama, Hiroyuki; Kobayashi, Eiichi; Sumitani, Kazushi; Agawa, Yoshiaki; Nagayama, Kunihito

    2010-01-01

    Ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) films were formed without initial nucleation using a coaxial arc plasma gun. The UNCD crystallite diameters estimated from the X-ray diffraction peaks were approximately 2 nm. The Fourier transform infrared absorption spectrum exhibited an intense sp3-CH peak that might originate from the grain boundaries between UNCD crystallites whose dangling bonds are terminated with hydrogen atoms. A narrow sp3 peak in the photoemission spectrum implied that the film comprises a large number of UNCD crystallites. Large optical absorption coefficients at photon energies larger than 3 eV that might be due to the grain boundaries are specific to the UNCD/a-C:H films.

  15. Low and non-waste process technology - Production of high-calorific fuel gas from waste oil using electric arc cracking

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Hyung; Kim, In Tae; Kim, Jeong Guk; Kim, Hwan Young; Cho, Kwang Hoon; Park, Hyun Soo [Korea Atomic Energy Research Institute, Taejon, (Korea)

    1999-04-01

    The generation amount of waste lubricating oil is the increasing trend. Environmental contamination is caused by an improper treatment of the waste oil or use of recycled fuel oil. Production of clean and high-calorific fuel gas from waste lubricating oil by electric arc cracking can protect the globe from contamination and save money as well. In this year, a laboratory-scale waste oil cracking process using direct discharge method was manufactured. Performance tests had been done under the various experimental conditions such as change of electrode specifications (material, shape, and dimension), amount of applied current, and discharge time. Characteristics of product gas (amount of production, constituents and composition), consumption of electrode and electric power were analyzed. The state-of-the-art on the electric arc cracking technology, experiences acquired through the design and manufacture of lab-scale arc cracking process, and experimental data were used to develop arc cracking technology and to manufacture the small-scale electric arc cracking process. 18 refs., 23 figs., 20 tabs. (Author)

  16. Effect of pulsed bias on the properties of ZrN/TiZrN films deposited by a cathodic vacuum arc

    Institute of Scientific and Technical Information of China (English)

    Zhang Guo-Ping; Wang Xing-Quan; Lü Guo-Hua; Zhou Lan; Huang Jun; Chen Wei; Yang Si-Ze

    2013-01-01

    .ZrN/TiZrN multilayers are deposited by using the cathodic vacuum arc method with different substrate bias (from 0 to-800 V),using Ti and Zr plasma flows in residual N2 atmosphere,combined with ion bombardment of sample surfaces.The effect of pulsed bias on the structure and properties of films is investigated.Microstructure of the coating is analyzed by X-ray diffraction (XRD),and scanning electron microscopy (SEM).In addition,nanohardness,Young's modulus,and scratch tests are performed.The experimental results show that the films exhibit a nanoscale multilayer structure consisting of TiZrN and ZrN phases.Solid solutions are formed for component TiZrN films.The dominant preferred orientation of TiZrN films is (111) and (220).At a pulsed bias of-200 V,the nanohardness and the adhesion strength of the ZrN/TiZrN multilayer reach a maximum of 38 GPa,and 78 N,respectively.The ZrN/TiZrN multilayer demonstrates an enhanced nanohardness compared with binary TiN and ZrN films deposited under equivalent conditions.

  17. The n-MAO/EPD bio-ceramic composite coating fabricated on ZK60 magnesium alloy using combined micro-arc oxidation with electrophoretic deposition

    Science.gov (United States)

    Xiong, Ying; Lu, Chao; Wang, Chao; Song, Renguo

    2014-12-01

    A bio-ceramic composite coating was fabricated on ZK60 magnesium (Mg) alloy using combined micro-arc oxidation (MAO) with electrophoretic deposition (EPD) technique. The MAO coating as the basal layer was produced in alkaline electrolyte with (n-MAO coating) and without (MAO coating) the addition of CeO2 and ZrO2 nano-particles, respectively. A hydroxyapatite (HA) coating as the covering layer was deposited on the n-MAO coating to improve the biological properties of the coating (n-MAO/EPD composite coating). The morphology and phase composition of three treated coatings were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The corrosion resistance of these coatings was evaluated with potentiodynamic polarization tests and immersion tests in simulated body fluid (SBF) at 36.5 ± 0.5 °C. The XRD spectra showed that the CeO2 and ZrO2 peaks can be collected in the n-MAO coating, and HA particles exists in the n-MAO/EPD composite coating. The results of corrosion tests indicated that the n-MAO/EPD composite coating owned increased bioactivity and long-term protective ability compared with the MAO coating and the n-MAO coating. Thus Mg alloy coated with the n-MAO/EPD composite coating should be more suited as biodegradable bone implants.

  18. The effect of nitrogen pressure during vacuum-arc tin coatings deposition on the erosion resistance in plasma of magnetron type discharges

    International Nuclear Information System (INIS)

    The erosion process was investigated of TiN coatings which were made with the vacuum-arc sputtering of Ti at the different nitrogen pressures (10-4...5X10-3 Torr). The erosion rates were measured by the weighting on analytical balance before and after treatment by plasmas of magnetron type, axial symmetrical discharges in nitrogen atmosphere, at the temperatures of 500...1100 C. It was shown that an erosion rate of TiN coatings deposited at low pressures (approx 1X10-4 Torr) is essentially (up to 1.5 times) lower than that for coatings produced at the more high pressures (5X10-3 Torr). For samples produced in the regime with high voltage pulses supply on substrate the erosion is lower than for coatings deposited in the regime without pulses supply. Taking into account the results of X-ray diffraction measurements, the physical mechanisms are suggested to explain such character of erosion behavior.

  19. Hydrogenation effects on carrier transport in boron-doped ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition

    International Nuclear Information System (INIS)

    Boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by coaxial arc plasma deposition with a boron-blended graphite target at a base pressure of <10−3 Pa and at hydrogen pressures of ≤53.3 Pa. The hydrogenation effects on the electrical properties of the films were investigated in terms of chemical bonding. Hydrogen-scattering spectrometry showed that the maximum hydrogen content was 35 at. % for the film produced at 53.3-Pa hydrogen pressure. The Fourier-transform infrared spectra showed strong absorptions by sp3 C–H bonds, which were specific to the UNCD/a-C:H, and can be attributed to hydrogen atoms terminating the dangling bonds at ultrananocrystalline diamond grain boundaries. Temperature-dependence of the electrical conductivity showed that the films changed from semimetallic to semiconducting with increasing hydrogen pressure, i.e., with enhanced hydrogenation, probably due to hydrogenation suppressing the formation of graphitic bonds, which are a source of carriers. Carrier transport in semiconducting hydrogenated films can be explained by a variable-range hopping model. The rectifying action of heterojunctions comprising the hydrogenated films and n-type Si substrates implies carrier transport in tunneling

  20. Effect of negative bias voltage on CrN films deposited by arc ion plating. II. Film composition, structure, and properties

    International Nuclear Information System (INIS)

    Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating at various negative bias voltages and several groups of N2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the arc ion plating (AIP) CrN films. In this article, the authors investigated the influence of negative bias voltage on the chemical composition, structure, and mechanical properties of the CrN films. The results showed that the chemical composition and phase structure of the AIP CrN films were greatly altered by application of negative bias voltage. Due to the selective resputtering effect, substoichiometric CrN films were obtained. With increase in bias voltages, the main phases in the films transformed from Cr+CrN to Cr2N at low N2/Ar flow ratios, whereas the films at high N2/Ar flow ratios retained the CrN phase structure. The CrN films experienced texture transformation from CrN (200) to CrN (220), and Cr2N (300) to Cr2N(300)+Cr2N(110). Increase in negative bias voltage also resulted in microstructure evolution of coarse columnar grains→fine columnar grains→quasiamorphous microstructure→recrystallized structures. From the experimental results, the authors proposed a new structure zone model based on enhanced bombardment of incident ions by application of negative bias voltage. The influence of negative bias voltage on the microhardness and residual stresses of the films and the inherent mechanisms were also explored

  1. Tantalum oxide nanocoatings prepared by atomic layer and filtered cathodic arc deposition for corrosion protection of steel: Comparative surface and electrochemical analysis

    International Nuclear Information System (INIS)

    Highlights: ► 50 nm Ta2O5 coatings grown by ALD at 160 °C and FCAD for protection of steel. ► Combined analysis by ToF-SIMS, XPS, polarization curves and EIS. ► Relation between chemical architecture and corrosion protection properties studied. ► Localized corrosion by pitting with absence of coating dissolution demonstrated. ► Origin and role of spurious interfacial oxide promoting coating breakdown emphasized. -- Abstract: A comparative study by Time-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i–E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized

  2. The structure and mechanical properties of multilayer nanocrystalline TiN/ZrN coatings obtained by vacuum-arc deposition

    Directory of Open Access Journals (Sweden)

    A.V. Demchyshyn

    2007-12-01

    Full Text Available TiN/ZrN multilayered condensates on BK-8 carbide tips substrates (62 HRC were produced by the vacuumarc deposition technique, using Ti and Zr plasma flows in reactive nitrogen gas medium with working pressure of 6.6·10–1 Pa. The TiN/ZrN multilayered condensates consist of TiN and ZrN sublayers, which have a thickness of ~100 nm, controlled by the processing parameters of the used deposition technique. The obtained coatings have hardness of 45 GPa and Young’s modulus of 320 GPa. The obtained results show that mechanical properties of such multilayered composites are considerably improved in comparison to those for the single-component coatings, TiN and ZrN. The dependence of hardness and Young’s modulus of the composites on sublayer thickness within a range of 100 nm was determined. The investigated structure and improved mechanical properties of the TiN/ZrN multilayered condensates would be very good platform for finding their industrial application, such as hard coatings with different purposes.

  3. The Porgera gold deposit, Papua, New Guinea, 1: association with alkalic magmatism in a continent-island-arc collision zone

    International Nuclear Information System (INIS)

    The meso thermal to epithermal Porgera gold deposit is spatially and temporally associated with shallow level (≤ 2 km emplacement depth) stocks and dykes of the Porgera Intrusive Complex (PIC). Gold mineralization immediately followed emplacement of the PIC, and is dated between 5 and 6 Ma ago. The Porgera intrusive suite is comprised of fine- to medium-grained, porphyritic to euhedral granular, volatile-rich, sodic alkali basalts/gabbros, hawaiites, and mugearites (TAS chemical classification scheme). The rocks display chemical and isotopic characteristics similar to those of intra plate alkalic basalts, but their unusually high volatile contents result in stabilization of hornblende as a phenocryst and intergranular phase in more evolved rock types. The observed order of cotectic crystallization is olivine - clinopyroxene - hornblende -plagioclase, with ubiquitous spinel (chromite/magnetite) and fluor-apatite. (author)

  4. Properties of Cr(C,N) hard coatings deposited in Ar-C2H2-N2 plasma

    International Nuclear Information System (INIS)

    Several chromium carbonitride (Cr-(C,N)) coatings were prepared with different C:N ratios by varying the N2 and C2H2 flow. Chromium nitride (Cr-N) and chromium carbide (Cr-C) coatings were also prepared for comparison. The coatings were deposited in two different ion-plating systems: by reactive evaporation in BAI730M (Balzers) apparatus at high temperature (450 deg. C) and by reactive sputtering in plasma-beam Sputron (Balzers) apparatus at low temperature (200 deg. C). Among mechanical properties microhardness, adhesion (measured by scratch test) and surface roughness were evaluated. Oxidation of the coatings was carried out by heating the samples at temperatures of 750-900 deg. C in an oxygen atmosphere. Crystal structure and microstructure were studied by XRD, TEM and SEM. Chemical State of the elements was observed by XPS. The concentration and depth profiles of the samples oxidized at various temperatures were measured by AES, EDX and GDOES

  5. Chemical vapour deposition synthetic diamond: materials, technology and applications

    OpenAIRE

    Balmer, R. S.; Brandon, J R; Clewes, S L; Dhillon, H. K.; Dodson, J M; Friel, I.; Inglis, P. N.; Madgwick, T D; Markham, M. L.; Mollart, T P; Perkins, N.; Scarsbrook, G. A.; Twitchen, D. J.; Whitehead, A J; Wilman, J J

    2009-01-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synt...

  6. The n-MAO/EPD bio-ceramic composite coating fabricated on ZK60 magnesium alloy using combined micro-arc oxidation with electrophoretic deposition

    International Nuclear Information System (INIS)

    Highlights: • Adding CeO2/ZrO2 nano-particles to modify the properties of n-MAO coating. • A bio-ceramic n-MAO/EPD composite coating was prepared by two-step methods. • The n-MAO/EPD composite coating with HA has a favorable anti-corrosion effect. - Abstract: A bio-ceramic composite coating was fabricated on ZK60 magnesium (Mg) alloy using combined micro-arc oxidation (MAO) with electrophoretic deposition (EPD) technique. The MAO coating as the basal layer was produced in alkaline electrolyte with (n-MAO coating) and without (MAO coating) the addition of CeO2 and ZrO2 nano-particles, respectively. A hydroxyapatite (HA) coating as the covering layer was deposited on the n-MAO coating to improve the biological properties of the coating (n-MAO/EPD composite coating). The morphology and phase composition of three treated coatings were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The corrosion resistance of these coatings was evaluated with potentiodynamic polarization tests and immersion tests in simulated body fluid (SBF) at 36.5 ± 0.5 °C. The XRD spectra showed that the CeO2 and ZrO2 peaks can be collected in the n-MAO coating, and HA particles exists in the n-MAO/EPD composite coating. The results of corrosion tests indicated that the n-MAO/EPD composite coating owned increased bioactivity and long-term protective ability compared with the MAO coating and the n-MAO coating. Thus Mg alloy coated with the n-MAO/EPD composite coating should be more suited as biodegradable bone implants

  7. Comparative study of the structure and corrosion behavior of Zr-20%Cr and Zr-20%Ti alloy films deposited by multi-arc ion plating technique

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Farhat, E-mail: ilatahraf@yahoo.com [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Mehmood, Mazhar, E-mail: mazhar@pieas.edu.pk [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Qasim, Abdul Mateen; Ahmad, Jamil; Naeem-ur-Rehman [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Iqbal, Muhammad [Physics Division, Pakistan Institute of Science and Technology (PINSTECH), Islamabad 45650 (Pakistan); Qureshi, Ammad H. [Materials Division, Pakistan Institute of Science and Technology (PINSTECH), Islamabad 45650 (Pakistan)

    2014-08-01

    The primary focus of the present work was to perform comparative study of the structure as well as corrosion behavior of two Zr-rich alloy films, i.e. Zr-20%Cr and Zr-20%Ti, as well as metallic Ti, Cr and Zr films, formed by multi-arc ion plating technique. The required alloy film composition was obtained by co-deposition with proper choice of current for the targets of the constituent metals. The deposited alloy film composition was determined by energy dispersion X-ray spectroscopy, X-ray fluorescence and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) techniques, which were in close agreement with each other. The film thickness lied in the range of 550-620 nm. The crystal structure was studied by X-ray diffraction, which revealed the formation of nanocrystalline and semi-amorphous structures. The corrosion rates of the films were determined through weight loss measurement in 1 M, 6 M and 12 M hydrochloric acid (HCl) by ICP-AES analysis of the solution after immersion for 200-350 h. Anodic (potentiodynamic) polarization was also performed. Zr-20%Cr alloy film exhibited the best corrosion resistance, and its dissolution rate was less than 0.5 μm/year in 6 M HCl and about 4 μm/year in 12 M HCl. - Highlights: • Fine control over the stoichiometry of each alloy film • Development of either nano-crystalline or semi-amorphous alloy films • Development of highly corrosion resistant films.

  8. The n-MAO/EPD bio-ceramic composite coating fabricated on ZK60 magnesium alloy using combined micro-arc oxidation with electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ying, E-mail: yxiong@zjut.edu.cn [College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Lu, Chao [College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Wang, Chao; Song, Renguo [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China)

    2014-12-15

    Highlights: • Adding CeO{sub 2}/ZrO{sub 2} nano-particles to modify the properties of n-MAO coating. • A bio-ceramic n-MAO/EPD composite coating was prepared by two-step methods. • The n-MAO/EPD composite coating with HA has a favorable anti-corrosion effect. - Abstract: A bio-ceramic composite coating was fabricated on ZK60 magnesium (Mg) alloy using combined micro-arc oxidation (MAO) with electrophoretic deposition (EPD) technique. The MAO coating as the basal layer was produced in alkaline electrolyte with (n-MAO coating) and without (MAO coating) the addition of CeO{sub 2} and ZrO{sub 2} nano-particles, respectively. A hydroxyapatite (HA) coating as the covering layer was deposited on the n-MAO coating to improve the biological properties of the coating (n-MAO/EPD composite coating). The morphology and phase composition of three treated coatings were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The corrosion resistance of these coatings was evaluated with potentiodynamic polarization tests and immersion tests in simulated body fluid (SBF) at 36.5 ± 0.5 °C. The XRD spectra showed that the CeO{sub 2} and ZrO{sub 2} peaks can be collected in the n-MAO coating, and HA particles exists in the n-MAO/EPD composite coating. The results of corrosion tests indicated that the n-MAO/EPD composite coating owned increased bioactivity and long-term protective ability compared with the MAO coating and the n-MAO coating. Thus Mg alloy coated with the n-MAO/EPD composite coating should be more suited as biodegradable bone implants.

  9. Effect of Silane Flow Rate on Structure and Corrosion Resistance of Ti–Si—N Thin Films Deposited by a Hybrid Cathodic Arc and Chemical Vapour Process

    International Nuclear Information System (INIS)

    Ti–Si–N thin films with different silicon contents are deposited by a cathodic arc technique in an Ar+N2 +SiH4 mixture atmosphere. With the increase of silane Bow rate, the content of silicon in the Ti–Si–N films varies from 2.0 at. % to 12.2 at. %. Meanwhile, the cross-sectional morphology of these films changes from an apparent columnar microstructure to a dense fine-grained structure. The x-ray diffractometer (XRD) and x-ray photoelectron spectroscopy (XPS) results show that the Ti–Si–N film consists of TiN crystallites and SiNx amorphous phase. The corrosion resistance is improved with the increase of silane Bow rate. Growth defects in the films produced play a key role in the corrosion process, especially for the local corrosion. The porosity of the films decreases from 0.13% to 0.00032% by introducing silane at the Bow rate of 14sccm. (gases, plasmas, and electric discharges)

  10. Effect of silane flow rate on structure and corrosion resistance of Ti-Si-N thin films deposited by a hybrid cathodic arc and chemical vapour process

    International Nuclear Information System (INIS)

    Ti-Si-N thin films with different silicon contents are deposited by a cathodic arc technique in an Ar+N2+SiH4 mixture atmosphere. With the increase of silane flow rate, the content of silicon in the Ti-Si-N films varies from 2.0 at.% to 12.2 at.%. Meanwhile, the cross-sectional morphology of these films changes from an apparent columnar microstructure to a dense fine-grained structure. The x-ray diffractometer (XRD) and x-ray photoelectron spectroscopy (XPS) results show that the Ti-Si-N film consists of TiN crystallites and SiNx amorphous phase. The corrosion resistance is improved with the increase of silane flow rate. Growth defects in the films produced play a key role in the corrosion process, especially for the local corrosion. The porosity of the films decreases from 0.13% to 0.00032% by introducing silane at the flow rate of 14 sccm. (authors)

  11. In situ composite coating of titania-hydroxyapatite on titanium substrate by micro-arc oxidation coupled with electrophoretic deposition processing

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yu [Department of Dental Biomaterials, School of Dentistry and Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Kim, Kyoung-A. [Department of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bio Science, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Park, Il Song, E-mail: ilsong@chonbuk.ac.kr [Department of Dental Biomaterials, School of Dentistry and Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Sook Jeong [Neural Injury Research Lab, Department of Neurology, Asan life Science Institute, University, of Ulsan, College of Medicine, Seoul 138-736 (Korea, Republic of); Bae, Tae Sung [Department of Dental Biomaterials, School of Dentistry and Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Min Ho, E-mail: mh@jbnu.ac.kr [Department of Dental Biomaterials, School of Dentistry and Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2011-09-15

    Highlights: {center_dot} HA/TiO{sub 2} coating were prepared by a MAO and EPD technique. {center_dot} The NaOH electrolyte solution containing HA particles is employed. {center_dot} MAO and EPD treatment enhances the corrosion resistance and bioactivity of titanium. - Abstract: In situ composite coating of hydroxyapatite (HA)/TiO{sub 2} were produced on titanium (Ti) substrate by micro-arc oxidation coupled with electrophoretic deposition (MAO and EPD) technique with different concentrations of HA particles in the 0.2 M NaOH electrolyte solution. The surface morphology and chemical composition of the hybrid coating were effected by HA concentration. The amount of HA particles incorporated into coating layer increased with increasing HA concentration used in the electrolyte solution. The corrosion behavior of the coating layer in simulated body fluids (SBF) was evaluated using a potentiodynamic polarization test. The corrosion resistance of the coated sample was increased compared to the untreated Ti sample. The in vitro bioactivity assessment showed that the MAO and EPD treated Ti substrate possessed higher apatite-forming ability than the untreated Ti. Moreover, the apatite-forming ability had a positive correlation with HA concentration. In addition, the cell behavior was also examined using cell proliferation assay and alkaline phosphatase ability. The coating formed at HA concentration of 5 g/L exhibited the highest cell ability.

  12. TiN/CrN multilayered hard coatings with TiCrN interlayer deposited by a filtered cathodic vacuum arc technique

    Institute of Scientific and Technical Information of China (English)

    Chengming Li; Qi He; Gang Lin; Xiaojun Sun; Weizhong Tang; Fanxiu Lu

    2004-01-01

    TiN/CrN multilayered hard coatings with TiCrN interlayer were deposited on high speed steel substrates by using a filtered cathodic vacuum arc technique. The structure and composition of the coatings were characterized by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). A high adhesion of up to 80 N was demonstrated by scratching tests for the multilayered coatings. Nanoindentation tests were performed to determine the hardness and elastic modulus of the coatings as a function of the multiplayer modulation period. It was observed that the hardness of the multilayered coatings is higher than those of either TiN or CrN single coatings, and it increases with decreasing modulation periods, which is consistent with predictions from the Hall-Perch type strengthening mechanism, though at small modulation periods, deviation from the Hall-Petch relation has been observed for the multilayered coatings. The life-span of drills coated with TiN/CrN multilayered is triple as long as that coated with TiN layer.

  13. Effect of negative bias voltage on CrN films deposited by arc ion plating. I. Macroparticles filtration and film-growth characteristics

    International Nuclear Information System (INIS)

    Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating (AIP) at various negative bias voltages and several groups of N2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the AIP CrN films. In this part (Part I), the investigations were mainly focused on the macroparticle distributions and film-growth characteristics. The results showed that macroparticle densities on the film surfaces decreased greatly by applying negative bias voltage, which can be affected by partial pressure of N2 and Ar gases. From the statistical analysis of the experimental results, they proposed a new hybrid mechanism of ion bombardment and electrical repulsion. Also, the growth of the AIP CrN films was greatly altered by applying negative bias voltage. By increasing the bias voltage, the film surfaces became much smoother and the films evolved from apparent columnar microstructures to an equiaxed microstructure. The impinging high-energy Cr ions accelerated by negative bias voltages were deemed the inherent reason for the evolution of growth characteristics

  14. Preparation technology and anti-corrosion performances of black ceramic coatings formed by micro-arc oxidation on aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    CHEN Ling; HAN Jing; YU Shengxue

    2006-01-01

    In order to prepare ornamental and anti-corrosive coating on aluminum alloys, preparation technology of black micro-arc ceramic coatings on Al alloys in silicate based electrolyte was studied.The influence of content of Na2WO4 and combination additive in solution on the performance of black ceramic coatings was studied; the anticorrosion performances of black ceramic coatings were evaluated through whole-immersion test and electrochemical method in 3.5% NaCl solution at different pH value; SEM and XRD were used to analyze the surface morphology and phase constitutes of the black ceramic coatings.Experimental results indicated that, without combination additives, with the increasing of Na2WO4 content in the electrolyte, ceramic coating became darker and thicker, but the color was not black; after adding combination additive, the coating turned to be black; the black ceramic coating was multi-hole form in surface.There was a small quantity of tungsten existing in the black ceramic coating beside α-Al2O3 phase and β-Al2O3 phase.And aluminum alloy with black ceramic coating exhibited excellent anti-corrosion property in acid, basic and neutral 3.5% NaCl solution.

  15. Abundances of platinum group elements in native sulfur condensates from the Niuatahi-Motutahi submarine volcano, Tonga rear arc: Implications for PGE mineralization in porphyry deposits

    Science.gov (United States)

    Park, Jung-Woo; Campbell, Ian H.; Kim, Jonguk

    2016-02-01

    Some porphyry Cu-Au deposits, which are enriched in Pd, are potentially an economic source of Pd. Magmatic volatile phases are thought to transport the platinum group elements (PGEs) from the porphyry source magma to the point of deposition. However, the compatibilities of the PGEs in magmatic volatile phases are poorly constrained. We report PGE and Re contents in native sulfur condensates and associated altered dacites from the Niuatahi-Motutahi submarine volcano, Tonga rear arc, in order to determine the compatibility of PGEs and Re in magmatic volatile phases, and their mobility during secondary hydrothermal alteration. The native sulfur we analyzed is the condensate of a magmatic volatile phase exsolved from the Niuatahi-Motutahi magma. The PGEs are moderately enriched in the sulfur condensates in comparison to the associated fresh dacite, with enrichment factors of 11-285, whereas Au, Cu and Re are strongly enriched with enrichment factors of ∼20,000, ∼5000 and ∼800 respectively. Although the PGEs are moderately compatible into magmatic volatile phases, their compatibility is significantly lower than that of Au, Cu and Re. Furthermore, the compatibility of PGEs decrease in the order: Ru > Pt > Ir > Pd. This trend is also observed in condensates and sublimates from other localities. PGE mineralization in porphyry Cu-Au deposits is characterized by substantially higher Pd/Pt (∼7-60) and Pd/Ir (∼100-10,500) than typical orthomagmatic sulfide deposits (e.g. Pd/Pt ∼0.6 and Pd/Ir ∼20 for the Bushveld). It has previously been suggested that the high mobility of Pd, relative to the other PGEs, may account for the preferential enrichment of Pd in porphyry Cu-Au deposits. However, the low compatibility of Pd in the volatile phase relative to the other PGEs, shown in this study, invalidates this explanation. We suggest that the PGE geochemistry of Pd-rich Cu-Au deposits is principally derived from the PGE characteristics of the magma from which the ore

  16. Next Generation Metallic Iron Nodule Technology in Electric Arc Steelmaking - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Donald R. Fosnacht; Iwao Iwasaki; Richard F. Kiesel; David J. Englund; David W. Hendrickson; Rodney L. Bleifuss

    2010-12-22

    The current trend in the steel industry is a gradual decline in conventional steelmaking from taconite pellets in blast furnaces, and an increasing number of alternative processes using metallic scrap iron, pig iron and metallized iron ore products. Currently, iron ores from Minnesota and Michigan are pelletized and shipped to the lower Great Lakes ports as blast furnace feed. The existing transportation system and infrastructure is geared to handling these bulk materials. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the needs of the emerging steel industry while utilizing the existing infrastructure and materials handling. A recent commercial installation employing Kobe Steel’s ITmk3 process, was installed in Northeastern Minnesota. The basic process uses a moving hearth furnace to directly reduce iron oxides to metallic iron from a mixture of iron ore, coals and additives. The resulting products can be shipped using the existing infrastructure for use in various steelmaking processes. The technology reportedly saves energy by 30% over the current integrated steelmaking process and reduces emissions by more than 40%. A similar large-scale pilot plant campaign is also currently in progress using JFE Steel’s Hi-QIP process in Japan. The objective of this proposal is to build upon and improve the technology demonstrated by Kobe Steel and JFE, by further reducing cost, improving quality and creating added incentive for commercial development. This project expands previous research conducted at the University of Minnesota Duluth’s Natural Resources Research Institute and that reported by Kobe and JFE Steel. Three major issues have been identified and are addressed in this project for producing high-quality nodular reduced iron (NRI) at low cost: (1) reduce the processing temperature, (2) control the furnace gas atmosphere over the NRI, and (3) effectively use sub

  17. Bioinspired peptide nanotubes: Deposition technology and physical properties

    International Nuclear Information System (INIS)

    Proteins and peptides have the intrinsic ability to self-assemble into elongated solid nanofibrils, which give rise to amyloid progressive neurodegenerative diseases (Alzheimer's, Parkinson, etc.). It has been found that of the core recognition motif of Aβ peptide is the diphenylalanine element. The diphenylalanine peptide can self-assemble into well-ordered peptide nanotubes (PNT). In this paper we report on our newly developed process-vapor deposition of PNT and 'bottom-up' nanotechnological techniques of PNT patterning. Study of several physical properties of PNT such as optical and electrochemical are presented. The results may lead to the development of a new generation of PNT-based bioinspired functional nanodevices.

  18. Application of induction plasma deposition technology for nuclear fuel fabrication

    International Nuclear Information System (INIS)

    A study on induction plasma deposition with ceramic materials, yttria-stabilized-zirconia ZrO2-Y2O3 (m.p. 2640oC), was conducted with a view of developing a new method for nuclear fuel fabrication. Before making dense pellets of more than 96% T.D., the spraying condition was optimized through the process parameters, such as chamber pressure, plasma plate power, powder spraying distance, sheath gas composition, probe position, particle size and powders of different morphology. The results with a 5 mm thick deposit on rectangular planar graphite substrates showed a 97.11% theoretical density when the sheath gas flow rate was Ar/H2 120/20 l/min, probe position 8 cm, particle size 75 μm and spraying distance 22 cm by AMDRY 146 powder. The degree of influence of the main effects on density were powder morphology, particle size, sheath gas composition, plate power and spraying distance, in that order. Among the two parameter interactions, the sheath gas composition and chamber pressure affects density greatly. By using the multi pellets mold of wheel type, the pellet density did not exceed 94% T.D., owing to the spraying angle. (author)

  19. Deposition Technology and Microhardness of Electrochemical Deposited Ni-W Alloy Nanocrystalline

    Institute of Scientific and Technical Information of China (English)

    WUYu-cheng; SHUXia; WANGLi-ping; HUXiao-ye; WANGWen-fang; HUANGXin-min

    2004-01-01

    In this paper, a perpendicular experiment was conducted by using 4 key process parmeters, such as concentration of sodium tungstate, current density, PH value and operaftng temperature, which have obvious influence on the electrodeposition of Ni-W alloy nanocrystalline. By extreme difference analysis, the influence of multi-factors on the deposition rate and microhardness and sultace quality of the nanocrystalline alloy coatings was studied in detail. By further contrastive experiment, the influence of single-factor on the electrodeposition of Ni-W alloy nanocrystalline was also discussod, which will provide basis for the preparation of Ni-W alloy nanocrystalline.

  20. Chemical vapour deposition synthetic diamond: materials, technology and applications

    Science.gov (United States)

    Balmer, R. S.; Brandon, J. R.; Clewes, S. L.; Dhillon, H. K.; Dodson, J. M.; Friel, I.; Inglis, P. N.; Madgwick, T. D.; Markham, M. L.; Mollart, T. P.; Perkins, N.; Scarsbrook, G. A.; Twitchen, D. J.; Whitehead, A. J.; Wilman, J. J.; Woollard, S. M.

    2009-09-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form; however, non-planar geometries are also possible and enable a number of key applications. This paper reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, on the basis of the ability to synthesize a consistent and engineered high performance product.

  1. Bioinspired peptide nanotubes: Deposition technology and physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Shklovsky, J.; Beker, P. [Department of Physical Electronics, School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Amdursky, N. [Department of Physical Electronics, School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv (Israel); Gazit, E. [Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv (Israel); Rosenman, G., E-mail: gilr@eng.tau.ac.il [Department of Physical Electronics, the School of Electrical Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel)

    2010-05-25

    Proteins and peptides have the intrinsic ability to self-assemble into elongated solid nanofibrils, which give rise to amyloid progressive neurodegenerative diseases (Alzheimer's, Parkinson, etc.). It has been found that of the core recognition motif of A{beta} peptide is the diphenylalanine element. The diphenylalanine peptide can self-assemble into well-ordered peptide nanotubes (PNT). In this paper we report on our newly developed process-vapor deposition of PNT and 'bottom-up' nanotechnological techniques of PNT patterning. Study of several physical properties of PNT such as optical and electrochemical are presented. The results may lead to the development of a new generation of PNT-based bioinspired functional nanodevices.

  2. Study of the feasibility of distributed cathodic arc as a plasma source for development of the technology for plasma separation of SNF and radioactive wastes

    Science.gov (United States)

    Amirov, R. Kh.; Vorona, N. A.; Gavrikov, A. V.; Liziakin, G. D.; Polistchook, V. P.; Samoylov, I. S.; Smirnov, V. P.; Usmanov, R. A.; Yartsev, I. M.

    2015-12-01

    One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics.

  3. Study of the feasibility of distributed cathodic arc as a plasma source for development of the technology for plasma separation of SNF and radioactive wastes

    International Nuclear Information System (INIS)

    One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics

  4. Study of the feasibility of distributed cathodic arc as a plasma source for development of the technology for plasma separation of SNF and radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Amirov, R. Kh.; Vorona, N. A.; Gavrikov, A. V.; Liziakin, G. D.; Polistchook, V. P.; Samoylov, I. S.; Smirnov, V. P.; Usmanov, R. A., E-mail: ravus46@yandex.ru; Yartsev, I. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-12-15

    One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics.

  5. Optimising of pipeline maintenance using deposit profile technology

    OpenAIRE

    Dahl, Johannes

    2014-01-01

    With an aging pipeline system, the petroleum industry is experiencing new challenges in maintaining the pipeline integrity. In the Master’s thesis, a method and technology for internal pipeline diameter detection is presented. By measuring the pressure signature during a conventional utility pigging operation, the changes in internal pipeline diameter are detected. The method is evaluated and its applicability for optimising the pipeline maintenance programme is discussed. The first par...

  6. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  7. Investigation of the life-time of drills covered with the anti-wear Cr(C,N complex coatings, deposited by means of Arc-PVD technique

    Directory of Open Access Journals (Sweden)

    J. Kusinski

    2009-03-01

    Full Text Available Purpose: This research was done to study the tribological behavior of twist HS6-5-2 drills covered with Cr/CrN/CrN+Cr2N/Cr(C, N and Cr/CrN/ Cr(C, N coatings as well as to obtain detailed information about microstructure and properties of investigated coatings.Design/methodology/approach: The coatings were deposited by the ARC-PVD process and examined revealing their microstructure: with the use of SEM and TEM microscopy and composition: chemical (EDS microanalysis and phase (XRD. Also microhardness, Young’s modulus and adhesion were measured using NHT CSEM hardness tester and scratch tester.Findings: The electron energy disspersive (EDS analysis of coatings showed higher concentration of nitrogen (in the internal coating-zone and carbon (in the external coating-zone. The X-ray diffractometry showed that coatings are mainly composed of CrN and Cr2N nitrides. The TEM analysis revealed that coating crystallization starts with nanometric Cr2N nitrides coherent with the ferrite matrix grains. The coatings turned out to improve the lifetime of the drills (much better than that of un-coated ones.Practical implications: The main aim of this work is to determine properties of multilayer and multi-component coatings on basis of Cr, C and N, which are potential candidates for replacing TiN coatings in certain applications.Originality/value: The paper contributes to better understanding of microstructure and properties of the coatings (chemical and phase composition, microhardness, Young’s modulus, adhesion, as well as lifetime of the coated drills.

  8. Effect of high-temperature plasma-deposited nano-overlays on the properties of long-period gratings written with UV and electric arc in non-hydrogenated fibers

    International Nuclear Information System (INIS)

    This work presents the effect of both high temperature (∼350 °C) and nano-overlay deposition on the performance of the long-period gratings (LPGs) written in non-hydrogenated standard fiber (Corning SMF28) and in photosensitive fibers (Fibercore PS1250/1500 and Nufern GF1) using UV exposure and electric arc discharge. Silicon nitride (SiNx) nano-coatings were deposited on LPGs at high temperature in a radio-frequency plasma-enhanced chemical-vapor-deposition process. The effect is discussed from a point of view of application of the gratings as platforms for high-temperature overlay deposition to enhance sensing properties of such LPGs. Our experiment shows that when deep resonances (∼20 dB) are desired only arc-induced gratings are suitable for high-temperature coating deposition or high temperature processing up to 350 °C. It is shown that the temperature-induced degradation effect for UV-written LPGs does not depend on composition of the core of the fiber and takes place for both photosensitive fibers. For some applications, where a resonance notch of only several dB is sufficient, high-temperature coating deposition and processing can still be applied to UV-written gratings. For the LPG written in GF1, a very low temperature sensitivity has been found. Moreover, our experimental results and simulations demonstrate that plasma-deposited high-refractive-index SiNx film (n = 2.37 @ λ = 1550 nm) with a thickness below only 80 nm can successfully tune the sensitivity of LPGs to a pre-designed external refractive index. Such deposition processes take typically only several minutes. (paper)

  9. X-ray photoelectron spectroscopy of nano-multilayered Zr-O/Al-O coatings deposited by cathodic vacuum arc plasma

    International Nuclear Information System (INIS)

    Nano-multilayered Zr-O/Al-O coatings with alternating Zr-O and Al-O layers having a bi-layer period of 6-7 nm and total coating thickness of 1.0-1.2 μm were deposited using a cathodic vacuum arc plasma process on rotating Si substrates. Plasmas generated from two cathodes, Zr and Al, were deposited simultaneously in a mixture of Ar and O2 background gases. The Zr-O/Al-O coatings, as well as bulk ZrO2 and Al2O3 reference samples, were studied using X-ray photoelectron spectroscopy (XPS). The XPS spectra were analyzed on the surface and after sputtering with a 4 kV Ar+ ion gun. High resolution angle resolved spectra were obtained at three take-off angles: 15o, 45o and 75o relative to the sample surface. It was shown that preferential sputtering of oxygen took place during XPS of bulk reference ZrO2 samples, producing ZrO and free Zr along with ZrO2 in the XPS spectra. In contrast, no preferential sputtering was observed with Al2O3 reference samples. The Zr-O/Al-O coatings contained a large amount of free metals along with their oxides. Free Zr and Al were observed in the coating spectra both before and after sputtering, and thus cannot be due solely to preferential sputtering. Transmission electron microscopy revealed that the Zr-O/Al-O coatings had a nano-multilayered structure with well distinguished alternating layers. However, both of the alternating layers of the coating contained of a mixture of aluminum and zirconium oxides and free Al and Zr metals. The concentration of Zr and Al changed periodically with distance normal to the coating surface: the Zr maximum coincided with the Al minimum and vice versa. However the concentration of Zr in both alternating layers was significantly larger than that of Al. Despite the large free metal concentration, the Knoop hardness, 21.5 GPa, was relatively high, which might be attributed to super-lattice formation or formation of a metal-oxide nanocomposite within the layers.

  10. Oxidation resistance of TiN, CrN, TiAlN and CrAlN coatings deposited by lateral rotating cathode arc

    International Nuclear Information System (INIS)

    In this paper, four kinds of hard coatings, TiN, CrN, TiAlN and CrAlN (with Al/Ti or Al/Cr atomic ratio around 1:1), were deposited on stainless steel substrates by a lateral rotating cathode arc technique. The as-deposited coatings were annealed in ambient atmosphere at different temperatures (500-1000 oC) for 1 h. The evolution of chemical composition, microstructure, and microhardness of these coatings after annealing at different temperatures was systematically analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and nanoindentation experiments. The oxidation behaviour and its influence on overall hardness of these four coatings were compared. It was found that the ternary TiAlN and CrAlN coatings have better oxidation resistance than their binary counterparts, TiN and CrN coatings. The Cr-based coatings (CrN and CrAlN) exhibited evidently better oxidation resistance than the Ti-based coatings (TiN and TiAlN). TiN coating started to oxidize at 500 oC. After annealing at 700 oC no N could be detected by EDX, indicating that the coating was almost fully oxidized. After annealed at 800 oC, the coating completely delaminated from the substrate. TiAlN started to oxidize at 600 oC. It was nearly fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 1000 oC. Both CrN and CrAlN started to oxidize at 700 oC. CrN was almost fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 900 oC. The oxidation rate of the CrAlN coating is quite slow. After annealing at 1000 oC, only about 19 at.% oxygen was detected and the coating showed no delamination. The Ti-based (TiN and TiAlN) coatings were not able to retain their hardness at higher temperatures (≥ 700 oC). On the other hand, the hardness of CrAlN was stable at a high level between 33 and 35 GPa up to an annealing temperature of 800 oC and still kept at a comparative high value of 18.7 GPa

  11. Decision making of technological system for exploitation of coal in “Brod - Gneotino” coal deposit

    OpenAIRE

    Panov, Zoran; Jovcevski, Saso; Mitrevski, Blagojce; Karakashev, Deljo

    2010-01-01

    In the paper is given a modern approach to the selection of technological system of coal exploitation. In addition, its are use of existing data mining projects and studies on the conditions that exist in deposit "Brod - Gneotino". In this case, it is given a perfect way for evaluation and quantification of the qualities of attributes for each of the alternatives. The selection was made with the using od three multicriteria metods. Key words> decision making, technological system, surface...

  12. The Effect of Nitrogen Gas Flow Rate on the Properties of TiN-COATED High-Speed Steel (hss) Using Cathodic Arc Evaporation Physical Vapor Deposition (pvd) Technique

    Science.gov (United States)

    Mubarak, Ali; Hamzah, Esah Binti; Mohd Toff, Mohd Radzi Hj.; Hashim, Abdul Hakim Bin

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN-coated HSS coupons. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester, and atomic force microscope (AFM). An increase in the nitrogen gas flow rate showed decrease in the formation of macro-droplets in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Surface roughness decreased with an increase in nitrogen gas flow rate but was higher than the uncoated polished sample. Microhardness of TiN-coated HSS coupons showed more than two times increase in hardness than the uncoated one. Scratch tester results showed good adhesion between the coating material and substrate. Considerable improvement in the properties of TiN-deposited thin films was achieved by the strict control of all operational steps.

  13. PHYSICAL VAPOR DEPOSITION OF TANTALUM ON GUN BARREL STEEL (SYSTEMS ANLAYSIS BRANCH, SUSTAINABLE TECHNOLOGY DIVISION, NRMRL)

    Science.gov (United States)

    This project entails the development of an alternative technology for plating gun barrel steel to replace the process electroplating of chrome (Cr-electroplate) with physical vapor deposition of tantalum (Ta-PVD). Developed by Benet Laboratory at Watervliet Arsenal, this project'...

  14. Analysis of Digital Control Technology of Inverter Arc Welding Power Supply%弧焊逆变电源的数字化控制技术分析

    Institute of Scientific and Technical Information of China (English)

    崔爱玲

    2015-01-01

    This paper discusses the characteristics and operating principle of digital-controlled inverter arc welding power supply,analyzes digital control technology of inverter arc welding power supply using TMS320LF2407 as the con-troller,and finally presents related hardware and software design.With the establishment of informationalized and digital platform,higher performance of inverter arc welding power supply is achieved.%论述了数字化弧焊电源系统的特征及弧焊逆变电源的工作原理,分析了以 TMS320LF2407为控制核心的弧焊逆变电源的数字化控制技术,给出了其数字化控制的硬件设计和软件设计。通过弧焊逆变电源的信息化、数字化平台的建立,实现了弧焊逆变电源更高性能的应用。

  15. Study on nanocomposite Ti–Al–Si–Cu–N films with various Si contents deposited by cathodic vacuum arc ion plating

    International Nuclear Information System (INIS)

    Highlights: ► XRD peaks show a tendency of decreasing intensity with increasing Si content. ► Ti–Al–Si–Cu–N films present different microstructure with increasing Si content. ► Films with 6 at.% Si content obtain the highest hardness, elastic modulus and H3/E2. ► The wear rate decreases with an increase in hardness. - Abstract: In this study, nanocomposite Ti–Al–Si–Cu–N films were deposited on high speed steel substrates by the vacuum cathode arc ion plating (AIP) technique. By virtue of X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM), the influence of silicon content on the film microstructure and characteristics was investigated systematically, including the chemical composition, crystalline structure as well as cross-section morphologies. With increasing the silicon content, a deterioration of the preferred orientation and a dense globular structure were detected. In the meanwhile, atomic force microscopy (AFM), nano-indentation, Rockwell indenter and reciprocating test were also utilized to analyze the hardness, elastic modulus, H3/E2, friction coefficient, adhesive strength and wear rate of the Ti–Al–Si–Cu–N films. The results showed that an optimal silicon content correlated with the best mechanical and tribological properties of the presented Ti–Al–Si–Cu–N films existed. With increasing the silicon content, the hardness, elastic modulus and the ratio H3/E2 first were improved gradually, and then were impaired sharply again. When the silicon content reached to 6 at.%, the film possessed the highest hardness, elastic modulus and ratio H3/E2 of approximately 24 GPa, 218 GPa and 0.31, respectively. Besides, films containing both 6 at.% and 10 at.% Si contents obtained a relatively low friction coefficient and a good adhesive strength. The wear rate decreased with an increase in hardness, with the highest hardness corresponding to a wear rate

  16. Study on nanocomposite Ti-Al-Si-Cu-N films with various Si contents deposited by cathodic vacuum arc ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Shi, J. [State Key Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Institute of Materials Engineering, University of Siegen, Paul-Bonatz-Strasse 9-11, Siegen 57076 (Germany); Muders, C.M.; Kumar, A. [Institute of Materials Engineering, University of Siegen, Paul-Bonatz-Strasse 9-11, Siegen 57076 (Germany); Jiang, X., E-mail: xin.jiang@uni-siegen.de [Institute of Materials Engineering, University of Siegen, Paul-Bonatz-Strasse 9-11, Siegen 57076 (Germany); Pei, Z.L.; Gong, J. [State Key Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Sun, C., E-mail: csun@imr.ac.cn [State Key Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer XRD peaks show a tendency of decreasing intensity with increasing Si content. Black-Right-Pointing-Pointer Ti-Al-Si-Cu-N films present different microstructure with increasing Si content. Black-Right-Pointing-Pointer Films with 6 at.% Si content obtain the highest hardness, elastic modulus and H{sup 3}/E{sup 2}. Black-Right-Pointing-Pointer The wear rate decreases with an increase in hardness. - Abstract: In this study, nanocomposite Ti-Al-Si-Cu-N films were deposited on high speed steel substrates by the vacuum cathode arc ion plating (AIP) technique. By virtue of X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM), the influence of silicon content on the film microstructure and characteristics was investigated systematically, including the chemical composition, crystalline structure as well as cross-section morphologies. With increasing the silicon content, a deterioration of the preferred orientation and a dense globular structure were detected. In the meanwhile, atomic force microscopy (AFM), nano-indentation, Rockwell indenter and reciprocating test were also utilized to analyze the hardness, elastic modulus, H{sup 3}/E{sup 2}, friction coefficient, adhesive strength and wear rate of the Ti-Al-Si-Cu-N films. The results showed that an optimal silicon content correlated with the best mechanical and tribological properties of the presented Ti-Al-Si-Cu-N films existed. With increasing the silicon content, the hardness, elastic modulus and the ratio H{sup 3}/E{sup 2} first were improved gradually, and then were impaired sharply again. When the silicon content reached to 6 at.%, the film possessed the highest hardness, elastic modulus and ratio H{sup 3}/E{sup 2} of approximately 24 GPa, 218 GPa and 0.31, respectively. Besides, films containing both 6 at.% and 10 at.% Si contents obtained a relatively low friction coefficient and a good adhesive

  17. Arcing phenomena in fusion devices workshop

    International Nuclear Information System (INIS)

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included

  18. Arcing phenomena in fusion devices workshop

    Energy Technology Data Exchange (ETDEWEB)

    Clausing, R.E.

    1979-01-01

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included.

  19. Arc Statistics

    CERN Document Server

    Meneghetti, M; Dahle, H; Limousin, M

    2013-01-01

    The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is compatible with observations, several studies were carried out which helped to significantly improve our knowledge of strong lensing clusters, unveiling their extremely complex internal structure. In particular, the abundance and the frequency of strong lensing events like gravitational arcs turned out to be a potentially very powerful tool to trace the structure formation. However, given the limited size of observational and theoretical data-sets, the power of arc statistics as a cosmological tool has been only minimally exploited so far. On the other hand, the last years were characterized by significant advancements in the field, and several cluster surveys that are ongoing or planned for the near future seem to have the potential to make arc statistics a competitive cosmo...

  20. Modeling Arcs

    CERN Document Server

    Insepov, Zeke; Veitzer, Seth; Mahalingam, Sudhakar

    2011-01-01

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gra- dient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  1. Remote sensing technology prospecting methods of interlayer oxidation zone type sandstone uranium deposit in Yili basin

    International Nuclear Information System (INIS)

    Taking Yili Basin as an example, remote sensing technology and method of interlayer oxidation zone type sandstone uranium deposit have systematically been summarized. Firstly, principle, methods and procedures of the second development of scientific experimental satellite photograph have been elaborated in detail. Three dimensional stereo simulation, display, and multi-parameters extraction have been recommended. Secondarily, the research is focused on prospective section image features in different type images and their geological implications and on establishing recognition keys of promising areas. Finally, based on above research results, three graded predictions, i.e. regional prospect, promising sections and favourable location in the deposit have been made step by step and reconnaissance and prospecting range are gradually reduced. The practice has indicated that breakthrough progress has been made in application to prospect prognosis of interlayer oxidation zone type sandstone uranium deposit and good verified results have been obtained

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  3. Plasma-based ion implantation and deposition: A review of physics,technology, and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, Jacques; Anders, Andre

    2005-05-16

    After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes used of PBII&D to produce surgical implants, bio- and blood-compatible surfaces and coatings, etc. With limitations, also non-conducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few eV up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process non-flat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures. We use the acronym PBII&D when referring to both implantation and deposition, while PBIID implies that deposition is part of the process.

  4. Supercritical water oxidation technology development paths for prevention of corrosion and deposition

    International Nuclear Information System (INIS)

    Supercritical Water Oxidation is being developed by the Department of Energy as a promising technology for treatment of mixed waste--that is waste that contains hazardous and radioactive constituents. The aim of this program has been to identify and resolve key technical challenges that have been barriers to commercialization of supercritical water oxidation. Initial testing with benchscale systems indicated that the overriding technical challenge for this technology was prevention of corrosion and deposition inside the reactor. A number of approaches are being pursued to resolve the issue of corrosion and deposition including alternate reactor designs, advanced material development and testing, salt separation processes, and analytical modeling of supercritical water oxidation systems. Ongoing projects in these areas are discussed along with plans for pilot plant testing with promising configurations

  5. STRENGTH OF ABS PARTS PRODUCED BY FUSED DEPOSITION MODELLING TECHNOLOGY – A CRITICAL ORIENTATION PROBLEM

    Directory of Open Access Journals (Sweden)

    Filip Górski

    2015-05-01

    Full Text Available Numerous experimental studies, including experiments performed by the authors, have shown that the part orientation during layer deposition has a very strong influence on final strength of a product manufactured by additive Fused Deposition Technology. The paper presents the results of tensile, bending and impact strength tests performed on samples of various orientations, made out of ABS material using FDM technology. The results of these tests allowed discovering a unique phenomenon – with the changing orientation, not only the values of strength indexes change, but macroscopic material behavior under load as well. The transition between a “yield point” and “brittle” material usually happens in a certain range of orientation values, named a critical orientation by the authors. The paper indicates supposed ranges of critical orientation for various types of loads.

  6. Technological peculiarities of deposition anti-reflective layers in low-e coatings

    Science.gov (United States)

    Yurjev, Y.; Sidelev, D.

    2013-12-01

    This article reports on the investigation of technological features magnetron sputtering for deposition anti-reflection layers in low-emission (low-e) coatings. The three-layer TiO2-Cu-TiO2 films were deposited by dual and planar magnetron sputtering systems (MS) on glass substrate. Studies of the current-voltage characteristics (CVC) and the hysteresis effect show that deposition of anti-reflection layers is possible in the transition mode with higher rates. For planar magnetron, the stability of electrical discharge parameters is achieved at 60 % O2 content in mixture. The calculations optical band gap Eg show that anti-reflective films have a rutile or anatase phases that depending on the content O2 in gas mixture. The optimum deposition conditions of TiO2 films were determined for all modifications of magnetrons. Anti-reflective layers, which are deposited by balanced dual MS, improve the transparency of low-e coatings (integral TVIS increase in 15%).

  7. Technological peculiarities of deposition anti-reflective layers in low-e coatings

    International Nuclear Information System (INIS)

    This article reports on the investigation of technological features magnetron sputtering for deposition anti-reflection layers in low-emission (low-e) coatings. The three-layer TiO2-Cu-TiO2 films were deposited by dual and planar magnetron sputtering systems (MS) on glass substrate. Studies of the current-voltage characteristics (CVC) and the hysteresis effect show that deposition of anti-reflection layers is possible in the transition mode with higher rates. For planar magnetron, the stability of electrical discharge parameters is achieved at 60 % O2 content in mixture. The calculations optical band gap Eg show that anti-reflective films have a rutile or anatase phases that depending on the content O2 in gas mixture. The optimum deposition conditions of TiO2 films were determined for all modifications of magnetrons. Anti-reflective layers, which are deposited by balanced dual MS, improve the transparency of low-e coatings (integral TVIS increase in 15%)

  8. The study of metal-alloy targets and excimer laser deposition technology

    CERN Document Server

    Xu Hua; Tang Yong Jian; Wu Wei Dong; Zhang Ji Cheng

    2002-01-01

    Pulsed Laser Deposition (PLD) technology is described. Design and manufacture of the PLD installation is illustrated in detail. The Cu films and Cu/Fe multi-layers are produced by PLD method. The production of the Mg/Si films using magnetron sputtering method is investigated in detail. The percent of Si on Mg/Si film surface is measured by using conductivity method

  9. Non-mine technology of hydrocarbon resources production at complex development of gas and coal deposits

    International Nuclear Information System (INIS)

    Non-mine technology of coal gas seams exploitation is new geological technological method of complex exploitation of coal gas deposits. The method allows sequentially to extract hydrocarbon resources in technological aggregative-mobile condensed states. According to natural methane content in seams the technology includes: methane extraction from sorption volume where it is bounded up with coal; gas output intensification of coal is due to structural changes of substance at the cost of physico-chemical treatment of seam; increase of seam permeability by the methods of active physical and physico-chemical actions on coal seam (hydro-uncovering, pneumatic hydro action etc.). Pilot testing shows efficiency of well mastering with help of depth pumps. In this case works of action of pumping out of operating liquid and gas extraction from coal seam are integrated

  10. Thermal Arc Spray Overview

    Science.gov (United States)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  11. Thermal Arc Spray Overview

    International Nuclear Information System (INIS)

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  12. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  13. Zeolite occurrence and genesis in the Late-Cretaceous Cayo arc of Coastal Ecuador: Evidence for zeolite formation in cooling marine pyroclastic flow deposits

    OpenAIRE

    Machiels, L.; Garces, D. (D.); Snellings, R.; Vilema, W.; Morante, F.; C Paredes; ELSEN, J

    2014-01-01

    This paper describes the quantitative mineralogy, the mineral chemistry and the distribution of natural zeolites over the outcrop area of the Late Cretaceous Cayo Formation of Coastal Ecuador (>1000 km(2)) and develops a model for zeolite alteration in the Cayo volcanic arc. Different zeolite types were identified: Ca-heulandite-type zeolites (clinoptilolite and heulandite), mordenite, laumontite, analcime, stilbite, epistilbite, chabazite, thomsonite and erionite. Zeolites occur over nearly ...

  14. Development of surface decontamination technology for radioactive waste using plasma. Dust behaviors in the treatment of oxide films using a low-pressure arc

    International Nuclear Information System (INIS)

    We are developing the surface treatment technique using low-pressure arc as a new decontamination technology for radioactive wastes from nuclear facilities. For the practical use, effective dust collection methods are necessary, because dust is generated from oxide films on the surface during the treatment. The method using gas stream and filters may be one of them, but the behavior of the dust has not been examined yet. We studied the basic behavior of the dust and the possibilities of dust control by gas stream as follows. 1. Most of the dust attached to the anode in the case of no gas blow. 2. Dust attachment to the anode was reduced to about half using small cross section type anode. It seems to be possible to reduce the dust attachment by proper choice of electrode shape. 3. The dust attachment was reduced to 10 to 40 percent by the gas blow to the side of arc. The dust control by gas stream might be possible. (author)

  15. Metal-AlN cermet solar selective coatings deposited by direct current magnetron sputtering technology

    Science.gov (United States)

    Zhang, Qi-Chu

    1998-02-01

    A series of metal-aluminium nitride (M-AlN) cermet materials for solar selective coatings was deposited by a novel direct current (d.c.) magnetron sputtering technology. Aluminium nitride was used as the ceramic component in the cermets, and stainless steel (SS), nickel-based alloy 0022-3727/31/4/003/img1 (NiCr), molybdenum-based alloy 0022-3727/31/4/003/img2 (TZM) and tungsten were used as the metallic components. The aluminium nitride ceramic and metallic components of the cermets were deposited by simultaneously running both an aluminium target and another metallic target in a gas mixture of argon and nitrogen. The ceramic component was deposited by d.c. reactive sputtering and the metallic component by d.c. non-reactive sputtering. The total sputtering gas pressure was 0.8-1.0 Pa and the partial pressure of reactive nitrogen gas was set at 0.020-0.025 Pa which is sufficiently high to ensure that a nearly pure AlN ceramic sublayer was deposited by d.c. reactive sputtering. Because of the excellent nitriding resistance of stainless steel and the other alloys and metal, a nearly pure metallic sublayer was deposited by d.c. sputtering at this low nitrogen partial pressure. A multilayered system, consisting of alternating metallic and AlN ceramic sublayers, was deposited by substrate rotation. This multisublayer system can be considered as a macrohomogeneous cermet layer with metal volume fraction determined by controlling the thicknesses of metallic and ceramic sublayers. Following this procedure, M-AlN cermet solar selective coatings with a double cermet layer structure were deposited. The films of these selective surfaces have the following structure: a low metal volume fraction cermet layer is placed on a high metal volume fraction cermet layer which in turn is placed on an aluminium metal infrared reflection layer. The top surface layer consists of an aluminium nitride antireflection layer. A solar absorptance of 0.92-0.96 and a normal emittance of 0.03-0.05 at

  16. Tectonostratigraphy and depositional history of the Neoproterozoic volcano-sedimentary sequences in Kid area, southeastern Sinai, Egypt: Implications for intra-arc to foreland basin in the northern Arabian-Nubian Shield

    Science.gov (United States)

    Khalaf, E. A.; Obeid, M. A.

    2013-09-01

    This paper presents a stratigraphic and sedimentary study of Neoproterozoic successions of the South Sinai, at the northernmost segment of the Arabian-Nubian Shield (ANS), including the Kid complex. This complex is composed predominantly of thick volcano-sedimentary successions representing different depositional and tectonic environments, followed by four deformational phases including folding and brittle faults (D1-D4). The whole Kid area is divisible from north to south into the lower, middle, and upper rock sequences. The higher metamorphic grade and extensive deformational styles of the lower sequence distinguishes them from the middle and upper sequences. Principal lithofacies in the lower sequence include thrust-imbricated tectonic slice of metasediments and metavolcanics, whereas the middle and upper sequences are made up of clastic sediments, intermediate-felsic lavas, volcaniclastics, and dike swarms. Two distinct Paleo- depositional environments are observed: deep-marine and alluvial fan regime. The former occurred mainly during the lower sequence, whereas the latter developed during the other two sequences. These alternations of depositional conditions in the volcano-sedimentary deposits suggest that the Kid area may have formed under a transitional climate regime fluctuating gradually from warm and dry to warm and humid conditions. Geochemical and petrographical data, in conjunction with field relationships, suggest that the investigated volcano-sedimentary rocks were built from detritus derived from a wide range of sources, ranging from Paleoproterozoic to Neoproterozoic continental crust. Deposition within the ancient Kid basin reflects a complete basin cycle from rifting and passive margin development, to intra-arc and foreland basin development and, finally, basin closure. The early phase of basin evolution is similar to various basins in the Taupo volcanics, whereas the later phases are similar to the Cordilleran-type foreland basin. The

  17. New production technology implementation to more efficiently and economically development of new uranium deposits

    International Nuclear Information System (INIS)

    processing characteristics of the ores. Considerable increase of the economic efficiency during the deposits mining is possible due to implementation of new technologies when uranium ore is mined and processed that will enable production energy intensity reduce, significant increase of labour productivity. For the last five years State Enterprise 'East Mining and Concentrating Combine' (uranium production centre) has conducted in-depth research and design work. The main efforts of the applied research were focused on the following activities: - heap and in-situ block leaching process design; - development of radiometric separators of new generation; - borehole in-situ leaching process improvement; - low-waste technology development for the ore deep mining; - process flow-sheet advancement for Hydrometallurgical Plant; - development of the technology for integrated processing of mining waste accumulated. The fulfilment of those efforts made possible to work out a fundamentally new approach to the strategy of new deposits' industrial exploitation as well as to complete the deposits being under operation now. The main trends of this strategy are as follows: - implementation of combined mining and chemical method of exploitation that implies that one part of reserves is mined by conventional method, the other part - by in-situ block leaching with creation of induced solid rock penetration by drilling-and-blasting and using sulfuric acid solution as a leaching agent; - application of update selective methods using efficient mechanically driven excavating, drilling and load-haul-dump equipment; - deep radiometric separation of all the mined ore with output of four products: high-grade concentrate to be processed at the Hydrometallurgical Plant; low-grade concentrate to be processed at the heap leaching ground; low active waste subject to ecologically safe long-term storing; commercial crushed stone suitable for highway and industrial engineering; - utilisation of heap leaching

  18. Vacuum arc under axial magnetic fields: experimental and simulation research

    International Nuclear Information System (INIS)

    Axial magnetic field (AMF) technology is a most important control method of vacuum arc, particularly for high-current vacuum arcs in vacuum interrupters. In this paper, a review of the state of current research on vacuum arcs under AMF is presented. The major aspects of vacuum arc in an AMF such as arc voltage, the motion of cathode spots, and anode activities are discussed, and the most recent progress both of experimental and simulation research is presented. (topical review)

  19. Research on geological modeling and integrated prognosis technologies for uranium deposit

    International Nuclear Information System (INIS)

    Due to continuously rapid development of China's national economy, the demand on energy is increasing urgently, therefore, nuclear power become one of the necessary to the sustainable development of China's future energy. With more and more effort on uranium exploration, undiscovered uranium mineralization near surface and in subsurface is getting less, and it is more and more difficult to find U deposit directly by traditional surface survey. To meet the higher demand in the evaluation and prognosis of U resources, this paper introduces detailedly and systematically the uranium geological modeling and the prognosis technologies through integrated geological data. Guided by geodynamics, metallogenic dynamics and U metallogenetic theory, the geotectonic, geophysical, geochemical and remote sensing data of the known U deposits has been studied to summarize the prognosis factors and build geological models of U deposits. The model and prognosis factors are then transformed into evaluation and prognosis model in GIS. With GIS we can, estimate U resource amount in analogy districts in the outlined U metallogenetic prognosis zone. All the above study have resulted in an integrate set of operating method and technical flow for U resource potential evaluation. (author)

  20. Variation of chemical composition of high strength low alloy steels with different groove sizes in multi-pass conventional and pulsed current gas metal arc weld depositions

    Directory of Open Access Journals (Sweden)

    K. Devakumaran

    2015-06-01

    Full Text Available 25 mm thick micro-alloyed HSLA steel plate is welded by multi-pass GMAW and P-GMAW processes using conventional V-groove and suitably designed narrow gap with 20 mm (NG-20 and 13 mm (NG-13 groove openings. The variation of weld metal chemistry in the multi pass GMA and P-GMA weld depositions are studied by spark emission spectroscopy. It is observed that the narrow groove GMA weld joint shows significant variation of weld metal chemistry compared to the conventional V-groove GMA weld joint since the dilution of base metal extends from the deposit adjacent to groove wall to weld center through dissolution by fusion and solid state diffusion. Further, it is noticed that a high rate of metal deposition along with high velocity of droplet transfer in P-GMAW process enhances the dilution of weld deposit and accordingly varies the chemical composition in multi-pass P-GMA weld deposit. Lower angle of attack to the groove wall surface along with low heat input in NG-13 weld groove minimizes the effect of dissolution by fusion and solid state diffusion from the deposit adjacent to groove wall to weld center. This results in more uniform properties of NG-13 P-GMA weld in comparison to those of NG-20 and CG welds.

  1. Surface Morphology and Properties of CrN Coating Deposited by Superimposed Pulse Bias Cathodic Arc Ion Deposition%脉冲偏压电弧离子镀CrN薄膜的表面形貌和性能研究

    Institute of Scientific and Technical Information of China (English)

    杨娟; 文晓霞; 卢春灿; 陈志谦; 聂朝胤

    2008-01-01

    采用脉冲偏压电孤离子镀技术沉积了CrN薄膜,并考察了在不同偏压下薄膜的表面形貌、相结构、显微硬度和耐磨性.随着偏压的增加,CrN薄膜表面颗粒运渐变少,表面粗糙度降低,结晶度增大,偏压为-100 V的CrN薄膜具有致密的表面结构,较高的硬度,最佳的抗磨性能.%In this study, the cathodic arc ion plating technique was used to deposit CrN films on stainless steel sub-strates. The mechanical properties of the cathodic arc ion deposited CrN films were correlated to the microstructure of the films, which in turn was determined by the vacuum arc deposition parameters. The goal of this study was to examine the effects of bias voltage on the surface morphology, phase structure, microhardness and wear resistance of CrN films. Various standard characterization techniques and equipment, such as X-ray diffraction, ball-on-disc friction tester, surface profilometer, scanning electronic microscopy, microindention system and optical microscopy, were used to analyze and qualify the surface morphology, the mechanical and tribological properties. With increasing e substrate bias voltages, the number of macroparticles decreased. The CrN coatings prepared at -100 V showed smooth surfaces, fine crystalline grains and high hardness and wear resistance.

  2. Alberta's Arc: it's taken on many stripes over the years, but Arc's devotion to oilsands research has remained true

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2005-06-30

    This article presented a history of the Alberta Research Council (ARC), the first provincial research council in Canada. Established to quantify Alberta's mineral resources, one of its primary focuses is on bitumen deposits. A background of ARC was provided, including details of its research and development initiatives. The agency fostered early research that would lead to a patent for the hot water separation process, followed by successful processing of 75 tons of bitumen at a pilot plant near Fort McMurray in 1930, and later provided funding for a separation plant at Bitumount. ARC also launched the first research into water flooding methods for in-situ extraction of bitumen from deeper formations. ARC's successful partnership with the Alberta Energy Research Initiative was discussed, with reference to its focus on thermal recovery, gas and solvent use, reservoir maintenance and cold production. ARC now serves almost 900 clients a year and is involved in research as diverse as micro fuel cells, genomics, manure-generated energy and the development of an e-coli vaccine. Although it continues to diversify, energy research remains a staple for ARC. It was concluded that new technological hurdles, such as meeting the oil sands' energy needs and reducing emissions, will ensure that research and development will remain a driver of future growth in Alberta. 7 figs.

  3. Thin Film Deposition Using Energetic Ions

    Directory of Open Access Journals (Sweden)

    Stephan Mändl

    2010-07-01

    Full Text Available One important recent trend in deposition technology is the continuous expansion of available processes towards higher ion assistance with the subsequent beneficial effects to film properties. Nowadays, a multitude of processes, including laser ablation and deposition, vacuum arc deposition, ion assisted deposition, high power impulse magnetron sputtering and plasma immersion ion implantation, are available. However, there are obstacles to overcome in all technologies, including line-of-sight processes, particle contaminations and low growth rates, which lead to ongoing process refinements and development of new methods. Concerning the deposited thin films, control of energetic ion bombardment leads to improved adhesion, reduced substrate temperatures, control of intrinsic stress within the films as well as adjustment of surface texture, phase formation and nanotopography. This review illustrates recent trends for both areas; plasma process and solid state surface processes.

  4. Scientific aspects of restricting development and application of micro-arc oxidation technology%制约微弧氧化技术应用开发的几个科学问题

    Institute of Scientific and Technical Information of China (English)

    蒋百灵; 刘东杰

    2011-01-01

    针对铝、镁合金微弧氧化技术应用开发中存在的溶质元素作用机理不明、电量消耗与陶瓷层增厚关系机制不清、所得陶瓷层性能尚不能满足苛刻环境下的耐蚀性要求等应用瓶颈,结合已有的试验结果,分析了微弧氧化陶瓷层形成和增厚过程中溶质元素的作用机制,探讨了通过溶液体系增加沉积层阻抗和依据等通量变换原理增大峰值电流两条途径缩短起弧时间以降低电量消耗的可能方法,提出了利用陶瓷层表面均布盲性微孔的形貌特征,制备有机-无机复合涂层的研究思想,以期为铝、镁合金微弧氧化处理的技术进步起到促进作用.%The development of and application of micro-arc oxidation (MAO) technology of aluminum and magnesium alloy were severely restricted by unknown mechanism of function of solute elements, unclear relationship between power consumption and ceramic coating thickness and undesirable resistance of the coating to harsh corrosive environment. The solute elements during MAO coating formation and growth was analyzed based on the previous experimental data. A possible way to lower power consumption by shortening arcing time was proposed and discussed, which can be carried out by increasing the deposited layer impedance using optimum electrolyte systems and promoting the peak current based on an isoflux transformation principle. An organic-inorganic duplex layers design was proposed to fabricate organic layer on the top blind micropores surface of MAO coating, with the purpose of promoting the coating performances and improving the MAO technical advance of Al and Mg alloys.

  5. Studies of diamond-like carbon and diamond-like carbon polymer hybrid coatings deposited with filtered pulsed arc discharge method for biomedical applications

    OpenAIRE

    Soininen, Antti

    2015-01-01

    Hydrogen free diamond-like carbon (DLC) coatings have been the subject of investigation all around the world for the last 30 years. One of the major problems in producing of thick high-quality DLC coatings has been the inadequate adhesion of the deposited film to the substrate. This obstacle is finally overcome by depositing an intermediate adhesion layer produced with high energy (>2 keV) carbon plasma before application of a high-quality coating produced with a low energy unit. To the best ...

  6. Acidic deposition: State of science and technology. Report 4. The regional acid deposition model and engineering model. Final report

    International Nuclear Information System (INIS)

    The report describes the Regional Acid Deposition Model (RADM), a constantly evolving system of computational models that describe the major physical and chemical processes involved in acid deposition on a regional scale. RADM was developed by the Acid Deposition Modeling Project (ADMP), established at the National Center for Atmospheric Research (NCAR) in 1983 to design, develop, and implement a comprehensive modeling system suitable for assessment studies to be conducted as part of the National Acid Precipitation Assessment Program (NAPAP). The project was based at NCAR until 1987, when it moved to the Atmospheric Sciences Research Center (ASRC) of the State University of New York (SUNY) at Albany as the focus of its work moved into model testing and application. The ADMP team developed the RADM system, performed preliminary evaluation, transferred the system to the Environmental Protection Agency (EPA), and participated in NAPAP studies designed to test RADM and develop applications for the model

  7. Arc saw development report

    International Nuclear Information System (INIS)

    The arc saw is one of the key components of the Contaminated Equipment Volume Reduction (CEVR) Program. This report describes the progress of the arc saw from its inception to its current developmental status. History of the arc saw and early contributors are discussed. Particular features of the arc saw and their advantages for CEVR are detailed. Development of the arc saw including theory of operation, pertinent experimental results, plans for the large arc saw and advanced control systems are covered. Associated topics such as potential applications for the arc saw and other arc saw installations in the world is also touched upon

  8. 电弧超声技术在焊接工艺中的应用研究%Application Research of Arc Ultrasonic Technology in the Welding Process

    Institute of Scientific and Technical Information of China (English)

    赵波

    2014-01-01

    对电弧超声技术的应用情况进行了综述,分析了电弧超声对焊接接头宏观形貌、焊缝及热影响区金相组织及力学性能的影响规律。分析表明,在电弧超声作用下,显著增强了焊接熔池搅拌作用、加快了焊接热传导,随着激励频率的增加,熔深基本不变,熔宽增大,粗晶区宽度减小,细晶区宽度增大;焊缝、熔合区、粗晶区、细晶区金相组织均明显细化,焊缝区的组织分布更趋均匀化;降低了焊接接头对热输入的敏感性,并使焊接接头在较高的焊接热输入水平下仍能具有良好的冲击韧性,尤其可显著提高焊接接头的低温冲击韧性;能够改善焊缝及其周围区域的残余应力分布,使其分布均匀,变化幅度减小。%The application situation of the arc ultrasonic technology was reviewed. And the influence rules of arc ultrasonic technology on the macrostructure of welded joint, metallurgical structure and mechanical properties of weld & HAZ were summarized and analyzed in this article. The analysis showed that under the effect of the arc ultrasonic technology, the shaking down effect of the molten welding pool is enhanced apparently and the welding heat conduction is accelerated. With the increase of the excitation frequency, the fusion penetration basically remains unchanged, the fusion width is enlarged, the coarse grain zone is narrowed, and the fine grain zone is widened;Meanwhile, the metallurgical structures of the weld, fusion area, coarse grain zone and fine grain zone are all refined obviously, and the microstructure of the weld metal tends to be more homogenized, which reduces the susceptivity of the weld joint to heat input, and ensure a favorable impact toughness (especially the impact toughness at low temperatures) of the weld joint even at a higher welding heat input level;it can also improve the distribution of residual stress in the weld and the area surrounding it and

  9. Recently developed technology in narrow gap welding of thick plates using the GMAW and submerged arc processes

    International Nuclear Information System (INIS)

    Device with weaving head for narrow gap welding suitable for the GMAW and SAW processes. Technological properties of welded joints on steels 20 MnMoNi 55 and 15 NiCuMoNb 5 having subjected to different heat treatments. (orig.)

  10. Measurement and modeling of a diamond deposition reactor: Hydrogen atom and electron number densities in an Ar/H2 arc jet discharge

    International Nuclear Information System (INIS)

    A combination of experiment [optical emission and cavity ring-down spectroscopy (CRDS) of electronically excited H atoms] and two-dimensional (2D) modeling has enabled a uniquely detailed characterization of the key properties of the Ar/H2 plasma within a ≤10-kW, twin-nozzle dc arc jet reactor. The modeling provides a detailed description of the initial conditions in the primary torch head and of the subsequent expansion of the plasma into the lower pressure reactor chamber, where it forms a cylindrical plume of activated gas comprising mainly of Ar, Ar+, H, ArH+, and free electrons. Subsequent reactions lead to the formation of H2 and electronically excited atoms, including H(n=2) and H(n=3) that radiate photons, giving the plume its characteristic intense emission. The modeling successfully reproduces the measured spatial distributions of H(n>1) atoms, and their variation with H2 flow rate, FH20. Computed H(n=2) number densities show near-quantitative agreement with CRDS measurements of H(n=2) absorption via the Balmer-β transition, successfully capturing the observed decrease in H(n=2) density with increased FH20. Stark broadening of the Balmer-β transition depends upon the local electron density in close proximity to the H(n=2) atoms. The modeling reveals that, at low FH20, the maxima in the electron and H(n=2) atom distributions occur in different spatial regions of the plume; direct analysis of the Stark broadening of the Balmer-β line would thus lead to an underestimate of the peak electron density. The present study highlights the necessity of careful intercomparisons between quantitative experimental data and model predictions in the development of a numerical treatment of the arc jet plasma. The kinetic scheme used here succeeds in describing many disparate observations--e.g., electron and H(n=2) number densities, spatial distributions of optical emission from the plume, the variation of these quantities with added flow of H2 and, when CH4 is added

  11. Multielement atmospheric deposition study in Croatia using moss biomonitoring, NAA, AAS and GIS technologies

    International Nuclear Information System (INIS)

    For the first time the moss biomonitoring technique and two complementary analytical techniques - neutron activation analysis (NAA) and atomic absorption spectrometry (AAS) - were applied to study multielement atmospheric deposition in the Republic of Croatia. Moss samples were collected during the summer 2006 from 98 sites evenly distributed over the country. Sampling was performed in accordance with the LRTAP Convention - ICP Vegetation protocol and sampling strategy of the European Programme on Biomonitoring of Heavy Metal Atmospheric Deposition. Conventional and epithermal neutron activation analyses made it possible to determine concentrations of 41 elements including key heavy metals such as Pb, Cd, Hg, and Cu determined by AAS. Principal component analysis (factor analysis with VARIMAX rotation) was applied to distinguish elements mainly of anthropogenic origin from those predominantly originating from natural sources. Geographical distribution maps of the elements over the sampled territory were constructed using GIS technology. The median values for Croatia are consistent with the corresponding values for all Europe for most elements. It was shown that the Adriatic coastline of Croatia may be considered as an environmentally pristine area. This study was conducted for providing reliable assessment of air quality throughout Croatia and producing information needed for better identification of pollution sources and improving the potential for assessing environmental and health risks in Croatia associated with toxic metals

  12. A Study on Reactive Spray Deposition Technology Processing Parameters in the Context of Pt Nanoparticle Formation

    Science.gov (United States)

    Roller, Justin M.; Maric, Radenka

    2015-12-01

    Catalytic materials are complex systems in which achieving the desired properties (i.e., activity, selectivity and stability) depends on exploiting the many degrees of freedom in surface and bulk composition, geometry, and defects. Flame aerosol synthesis is a process for producing nanoparticles with ample processing parameter space to tune the desired properties. Flame dynamics inside the reactor are determined by the input process variables such as solubility of precursor in the fuel; solvent boiling point; reactant flow rate and concentration; flow rates of air, fuel and the carrier gas; and the burner geometry. In this study, the processing parameters for reactive spray deposition technology, a flame-based synthesis method, are systematically evaluated to understand the residence times, reactant mixing, and temperature profiles of flames used in the synthesis of Pt nanoparticles. This provides a framework for further study and modeling. The flame temperature and length are also studied as a function of O2 and fuel flow rates.

  13. Chemical vapour deposition of tungsten and tungsten silicide layers for applications in novel silicon technology

    CERN Document Server

    Li, F X

    2002-01-01

    This work was a detailed investigation into the Chemical Vapour Deposition (CVD) of tungsten and tungsten silicide for potential applications in integrated circuit (IC) and other microelectronic devices. These materials may find novel applications in contact schemes for transistors in advanced ICs, buried high conductivity layers in novel Silicon-On-Insulator (SOI) technology and in power electronic devices. The CVD techniques developed may also be used for metal coating of recessed or enclosed features which may occur in novel electronic or electromechanical devices. CVD of tungsten was investigated using the silicon reduction reaction of WF sub 6. W layers with an optimum self-limiting thickness of 100 nm and resistivity 20 mu OMEGA centre dot cm were produced self-aligned to silicon. A hydrogen passivation technique was developed as part of the wafer pre-clean schedule and proved essential in achieving optimum layer thickness. Layers produced by this approach are ideal for intimate contact to shallow junct...

  14. A comparison study between atomic and ionic nitrogen doped carbon films prepared by ion beam assisted cathode arc deposition at various pulse frequencies

    International Nuclear Information System (INIS)

    A comparison study of microstructure and bonds composition of carbon nitride (CNx) films fabricated at atomic and ionic nitrogen source by pulse cathode arc method was presented. The relative fractions of CN/CC bonds, N-sp3C/N-sp2C and graphite-like/pyridine-like N bonding configurations in the CN films were evaluated by combining C1s and N1s X-ray photoelectron spectroscopy with the hardness and optical band gap measurement. The dependence of microstructure (quantity, size and disordering degree of Csp2 clusters) of CNx films on the nitrogen source and pulse frequency was determined by Raman spectroscopy. Films with high atomic ratio of nitrogen/carbon (0.17) and high hardness were produced at ionic nitrogen source and low pulse frequency. The results showed that ionic nitrogen source facilitated the formation of CN bonds and N-sp2C bonding configurations (mainly in graphite-like N form). Moreover presenting an optimum pulse frequency (∼10 Hz) leaded to the most nitrogen coordinated with sp3-C and the highest ratio of CN/CC bonds in the CNx films. An equilibrium action mechanism might exist between the quantity and energy of carbon and nitrogen ions/atoms, giving more nitrogen-incorporated carbon materials. These allow us to obtain the high content of N-Csp3 bonding and expected bonding structure by optimizing pulse frequency and nitrogen source.

  15. Properties of weld deposit for butt weldings of reactor components

    International Nuclear Information System (INIS)

    Mechanical properties of weld deposit type MnNiMo from submerged arc- and manual shielded arc weldings for reactor components, influence of chemical composition and heat treatment condition, proposal for the testing of mechanical properties for weld deposit. (orig.)

  16. Implementing RapidArc into clinical routine

    DEFF Research Database (Denmark)

    Van Esch, Ann; Huyskens, Dominique P; Behrens, Claus F;

    2011-01-01

    With the increased commercial availability of intensity modulated arc therapy (IMAT) comes the need for comprehensive QA programs, covering the different aspects of this newly available technology. This manuscript proposes such a program for the RapidArc (RA) (Varian Medical Systems, Palo Alto) I...

  17. Development of surface decontamination technology for radioactive waste using plasma. Improvement in decontamination performance of low-pressure-arc by atmospheric gas

    International Nuclear Information System (INIS)

    We have been studying a Dry Surface Decontamination Technology using Low-Pressure-Arc (LPA), characterized by less secondary wastes etc. Until now, a 60Co residual rate of almost 20% was achieved at pressures of several tens of pascals in an argon atmosphere for BWR corrosion product film test pieces containing major contaminant radionuclide, 60Co. A 20% 60Co residual rate may be regarded as practical level of decontamination performance. On the contrary, we suggested the radioactive dust collection method using gas flow in treating, and found that this method was only effective at pressures above hundreds of pascals. But in this pressure range, we could not achieve a 20% 60Co residual rate. Therefore we have investigated decontamination performance of the LPA when carbon monoxide gas was added to an atmosphere of argon. The reason was that we expected an improvement in the decontamination performance of the LPA due to a chemical reaction caused by carbon monoxide, besides the heat effects of the LPA. As a result, in the case of the mixed gases (Ar/CO = 80/20-50/50), almost 20%60Co residual rate was achieved even at pressures of around hundreds of pascals. The addition of carbon monoxide to the argon atmosphere facilitates the application of this collection method. (author)

  18. Influence of modulation period and modulation ratio on structure and mechanical properties of TiBN/CrN coatings deposited by multi-arc ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, S.Y.; Yan, S.J.; Han, B. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Yang, B. [School of Power and Mechanical Engineering, Wuhan University, 430072 Wuhan (China); Lin, B.Z.; Zhang, Z.D.; Ai, Z.W. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Pelenovich, V.O. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Institute of Ion-Plasma and Laser Technologies, Academy of Sciences of Uzbekistan, 700135 Tashkent (Uzbekistan); Fu, D.J., E-mail: djfu@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China)

    2015-10-01

    Highlights: • TiBN/CrN multilayers were synthesized with varied modulation period and ratio. • The maximum hardness of 38.6 GPa is observed at Λ = 11.7 nm and R = 5:1. • The lowest multilayer COF of 0.32 is lower than that of CrN (0.56). • The wear rate of the coatings is improved and related to H/E and H{sup 3}/E{sup *2} ratios. - Abstract: TiBN/CrN multilayered superlattice coatings with modulation periods Λ (bilayer thickness) ranging from 22.5 to 4.2 nm and modulation ratio R (the thickness ratio of CrN and TiBN layers) ranging from 6:1 to 3:1 were synthesized using an industrial-scale cathodic arc ion plating system in an Ar–N{sub 2} gas mixture. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindention were employed to investigate the influence of modulation period and ratio on microstructure and mechanical properties of the multilayers. The sharp interfaces and nanoscale multilayered modulation were confirmed by TEM. TiBN/CrN multilayer coatings were crystallized with orientations at the (1 1 1), (2 0 0) and (2 2 0) crystallographic planes and the microstructure was strengthened at (2 0 0) preferred orientation. The maximum hardness of 38.6 GPa and elastic modulus of 477 GPa were obtained at Λ = 11.7 nm and R = 5:1. The lowest value of the friction coefficient at 0.32 sliding against a WC-Co ball was obtained at a bilayer period of 11.7 nm, compared to those of the coatings with other modulation periods and monolithic coatings. The wear rate of the multilayered coatings was also lower than those of the monolithic CrN and TiBN coatings.

  19. Influence of modulation period and modulation ratio on structure and mechanical properties of TiBN/CrN coatings deposited by multi-arc ion plating

    International Nuclear Information System (INIS)

    Highlights: • TiBN/CrN multilayers were synthesized with varied modulation period and ratio. • The maximum hardness of 38.6 GPa is observed at Λ = 11.7 nm and R = 5:1. • The lowest multilayer COF of 0.32 is lower than that of CrN (0.56). • The wear rate of the coatings is improved and related to H/E and H3/E*2 ratios. - Abstract: TiBN/CrN multilayered superlattice coatings with modulation periods Λ (bilayer thickness) ranging from 22.5 to 4.2 nm and modulation ratio R (the thickness ratio of CrN and TiBN layers) ranging from 6:1 to 3:1 were synthesized using an industrial-scale cathodic arc ion plating system in an Ar–N2 gas mixture. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindention were employed to investigate the influence of modulation period and ratio on microstructure and mechanical properties of the multilayers. The sharp interfaces and nanoscale multilayered modulation were confirmed by TEM. TiBN/CrN multilayer coatings were crystallized with orientations at the (1 1 1), (2 0 0) and (2 2 0) crystallographic planes and the microstructure was strengthened at (2 0 0) preferred orientation. The maximum hardness of 38.6 GPa and elastic modulus of 477 GPa were obtained at Λ = 11.7 nm and R = 5:1. The lowest value of the friction coefficient at 0.32 sliding against a WC-Co ball was obtained at a bilayer period of 11.7 nm, compared to those of the coatings with other modulation periods and monolithic coatings. The wear rate of the multilayered coatings was also lower than those of the monolithic CrN and TiBN coatings

  20. Variation of chemical composition of high strength low alloy steels with different groove sizes in multi-pass conventional and pulsed current gas metal arc weld depositions

    OpenAIRE

    K. Devakumaran; M.R. Ananthapadmanaban; P. K. Ghosh

    2015-01-01

    25 mm thick micro-alloyed HSLA steel plate is welded by multi-pass GMAW and P-GMAW processes using conventional V-groove and suitably designed narrow gap with 20 mm (NG-20) and 13 mm (NG-13) groove openings. The variation of weld metal chemistry in the multi pass GMA and P-GMA weld depositions are studied by spark emission spectroscopy. It is observed that the narrow groove GMA weld joint shows significant variation of weld metal chemistry compared to the conventional V-groove GMA weld joint ...

  1. Laser beam soldering of fine-pitch technology packages with solid solder deposits

    Science.gov (United States)

    Pucher, Hans-Joerg; Glasmacher, Mathias; Geiger, Manfred

    1996-04-01

    Micro electronics is a key technology attracting the attention of information, communication, automation and data processing technologies. Ongoing miniaturization combined with an increasing number of I/Os has inevitably lead to ever finer lead geometries. Therefore the demands put upon the surface mount technology are increasing continuously. Processing of high lead count fine pitch packages, for example those which are applied in high-capacity computers, has not increased the demands put upon the assembly process only, but also on the connecting techniques. By reflow soldering with laser beam radiation the benefits from the tool `laser beam' are used extensively, for example contact and force free processing, strictly localized heating and the good controllability thereof, formation of fine crystalline and homogeneous structures, etc. Within the scope of this paper the fundamentals of laser beam soldering are discussed for fine pitch lead frames (pitch 300 micrometers ) for plastic packages, made by a modified CuFe2P alloy with a 5 micrometers Sn90Pb plating, on solid solder depths (Sn63Pb) performed by the so called High-Pad process. These investigations are unique in the field of laser beam soldering and are carried out by means of a Nd:YAG-laser. A pyrometer is used for detection of the emission of the temperature radiation of the joining area for process control. The additional use of a high-speed camera gives a detailed description of the melting and wetting process. The influence of laser beam parameters and the volume of the solid solder deposits on the joining result are presented.

  2. Characteristics, extent and origin of hydrothermal alteration at Mount Rainier Volcano, Cascades Arc, USA: Implications for debris-flow hazards and mineral deposits

    Science.gov (United States)

    John, D.A.; Sisson, T.W.; Breit, G.N.; Rye, R.O.; Vallance, J.W.

    2008-01-01

    Hydrothermal alteration at Mount Rainier waxed and waned over the 500,000-year episodic growth of the edifice. Hydrothermal minerals and their stable-isotope compositions in samples collected from outcrop and as clasts from Holocene debris-flow deposits identify three distinct hypogene argillic/advanced argillic hydrothermal environments: magmatic-hydrothermal, steam-heated, and magmatic steam (fumarolic), with minor superimposed supergene alteration. The 3.8??km3 Osceola Mudflow (5600??y BP) and coeval phreatomagmatic F tephra contain the highest temperature and most deeply formed hydrothermal minerals. Relatively deeply formed magmatic-hydrothermal alteration minerals and associations in clasts include quartz (residual silica), quartz-alunite, quartz-topaz, quartz-pyrophyllite, quartz-dickite/kaolinite, and quartz-illite (all with pyrite). Clasts of smectite-pyrite and steam-heated opal-alunite-kaolinite are also common in the Osceola Mudflow. In contrast, the Paradise lahar, formed by collapse of the summit or near-summit of the edifice at about the same time, contains only smectite-pyrite and near-surface steam-heated and fumarolic alteration minerals. Younger debris-flow deposits on the west side of the volcano (Round Pass and distal Electron Mudflows) contain only low-temperature smectite-pyrite assemblages, whereas the proximal Electron Mudflow and a hydrothermal alteration minerals that are exposed in the avalanche headwall of Sunset Amphitheater, reflecting progressive incision into deeper near-conduit alteration products that formed at higher temperatures. The pre-Osceola Mudflow alteration geometry is inferred to have consisted of a narrow feeder zone of intense magmatic-hydrothermal alteration limited to near the conduit of the volcano, which graded outward to more widely distributed, but weak, smectite-pyrite alteration within 1??km of the edifice axis, developed chiefly in porous breccias. The edifice was capped by a steam-heated alteration zone, most

  3. Deposition and Damping Property of Arc Ion Plated NiCrAlY Coatings%基底偏压对电弧离子镀NiCrAlY涂层阻尼性能的影响

    Institute of Scientific and Technical Information of China (English)

    杜广煜; 谭祯; 孙伟; 柴昊; 巴德纯; 韩清凯

    2012-01-01

    The NiCrAlY coatings were deposited by arc ion plating on stainless steel substrates. The effects of the deposition conditions, such as the pressure, substrate bias, and arc current, on damping property of the NiCrAlY coatings were evaluated. The rnicrostructures and damping property were characterized with X-ray diffraction, scanning electron microscopy and dynamic mechanical analyzer. The results show that the substrate bias significantly improves the damping properties of the NiCrAlY coating. For example, the damping factor of the NiCrAlY coated stainless steel substrate increased with an increase of the bias voltage. The fairly smooth, compact NiCrAlY coatings mainly consisted of γ-Ni, α-NiAl,γ-Ni3Al,and α- Cr phases.%采用电弧离子镀方法在不锈钢基片上制备了NiCrAlY涂层,在制备过程中改变基底偏压分别取50,100,200,300V.对涂层样品分别进行物相分析,表面形貌观察,测定微区化学成分,并利用动态机械分析仪(DMA)对涂层样品的阻尼性能进行测试.结果表明,利用电弧离子镀的方法可以在不锈钢基底上获得均匀的NiCrAlY涂层.涂层为晶态结构,主要由γ-Ni相,β-NiAl相,γ'-Ni3Al相和α-Cr组成.制备过程中的偏压变化对涂层的表面形貌有明显影响,对涂层的化学成分影响不大.DMA结果表明NiCrAlY涂层能明显地提高基底材料的阻尼性能,同时随着偏压增大,涂层样品的阻尼因子有所提高.

  4. Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors II: Modeling of the spatial dependence of expanded plasma parameters and species number densities

    International Nuclear Information System (INIS)

    Detailed methodology and results are presented for a two-dimensional (r,z) computer model applicable to dc arc jet reactors operating on argon/hydrogen/hydrocarbon gas mixtures and used for chemical vapor deposition of micro- and nanocrystalline diamond and diamondlike carbon films. The model incorporates gas activation, expansion into the low pressure reactor chamber, and the chemistry of the neutral and charged species. It predicts the spatial variation of temperature, flow velocities and number densities of 25 neutral and 14 charged species, and the dependence of these parameters on the operating conditions of the reactor such as flows of H2 and CH4 and input power. Selected outcomes of the model are compared with experimental data in the accompanying paper [C. J. Rennick et al., J. Appl. Phys. 102, 063309 (2007)]. Two-dimensional spatial maps of the number densities of key radical and molecular species in the reactor, derived from the model, provide a summary of the complicated chemical processing that occurs. In the vortex region beyond the plume, the key transformations are CH4→CH3↔C2H2↔large hydrocarbons; in the plume or the transition zone to the cooler regions, the chemical processing involves C2Hx↔(CHy and CHz), C3Hx↔(CHy and C2Hz), (C2Hy and C2Hz)↔C4Hx↔(CHy and C3Hz). Depending on the local gas temperature Tg and the H/H2 ratio, the equilibria of H-shifting reactions favor C, CH, and C2 species (in the hot, H-rich axial region of the plume) or CH2, C2H, and C2H2 species (at the outer boundary of the transition zone). Deductions are drawn about the most abundant C-containing radical species incident on the growing diamond surface (C atoms and CH radicals) within this reactor, and the importance of chemistry involving charged species is discussed. Modifications to the boundary conditions and model reactor geometry allow its application to a lower power arc jet reactor operated and extensively studied by Jeffries and co-workers at SRI

  5. The Late Cambrian Takaka Terrane, NW Nelson, New Zealand: Accretionary-prism development and arc collision followed by extension and fan-delta deposition at the SE margin of Gondwana

    Science.gov (United States)

    Pound, K. S.

    2013-12-01

    Re-evaluation of field and lab data indicates that the Cambrian portion of the Takaka Terrane in the Cobb Valley area of NW Nelson, New Zealand preserves the remnants of an accretionary prism complex, across which the Lockett Conglomerate fan-delta was deposited as a consequence of extension. Previous work has recognized that the structurally disrupted lower Takaka Terrane rocks present an amalgam of sedimentary and igneous rocks generated prior to convergence (Junction Formation) or during convergence (Devil River Volcanics Group, Haupiri Group), including arc-related and MORB components. Portions of the sequence have in the past been loosely described as an accretionary prism. Reevaluation of the detailed mapping, sedimentological and provenance studies shows that remnants of a stratigraphic sequence (Junction Formation, Devil River Volcanics Group, Haupiri Group) can be traced through 10 fault-bounded slices, which include a mélange-dominated slice (Balloon Mélange). These slices are the remnants of the accretionary prism; the stratigraphy within each slice generally youngs to the east, and the overall pattern of aging (based on relative age from provenance studies, sparse fossils, stratigraphic relations, and limited isotopic data) indicates that the older rocks generally dominate fault slices to the east, and younger rocks dominate fault slices to the west, delineating imbricate slices within an eastward-dipping subduction zone, in which the faults record a complex history of multi-phase reactivation. The Lockett Conglomerate is a ~500-m thick fan-delta conglomerate that is the preserved within one of the fault slices, where it is stratigraphically and structurally highest unit in the lower Takaka Terrane; it is also present as blocks within the Balloon Melange. The Lockett Conglomerate is marine at its base and transitions upwards to fluvial facies. The Lockett Conglomerate has previously been interpreted to result from erosion consequent on continued

  6. Rotating arc spark plug

    Science.gov (United States)

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  7. Arc flash hazard analysis and mitigation

    CERN Document Server

    Das, J C

    2012-01-01

    "All the aspects of arc flash hazard calculations and their mitigation have been covered. Knowledge of electrical power systems up to undergraduate level is assumed. The calculations of short-circuits, protective relaying and varied electrical system configurations in industrial power systems are addressed. Protection systems address differential relays, arc flash sensing relays, protective relaying coordination, current transformer operation and saturation and applications to major electrical equipments from the arc flash considerations. Current technologies and strategies for arc flash mitigation have been covered. A new algorithm for the calculation of arc flash hazard accounting for the decaying nature of the short-circuit currents is included. There are many practical examples and study cases. Review questions and references follow each chapter"--

  8. Atomic layer deposition: a key technology for the controlled growth of oxide thin films for advanced applications

    International Nuclear Information System (INIS)

    Atomic layer deposition (ALD), also referred to as atomic layer epitaxy (ALE), was originally developed to process thin film electroluminescent structures for flat panel displays, which include as core components also insulating oxide layers such as alumina and aluminium titanium oxide. Another early application of oxide ALD was the processing of overlayers for catalysts. More recently, a major breakthrough for the ALD technology is the use of oxide thin films in microelectronics as gate and dynamic random access memory capacitor dielectrics. Besides giving a brief introduction to the ALD/ALE technology, the paper will address the present status of depositing binary and more complex (i.e. perovskite-type) metal oxides emphasizing precursor chemistry. (author)

  9. 船舶电气支件焊接中电弧螺柱焊技术的应用%Application of Arc Stud Welding Technology in Marine Electrical Branch Welding

    Institute of Scientific and Technical Information of China (English)

    郭佳

    2015-01-01

    The arc stud welding technology is a widely used welding method,has high stud welding efficiency and many advantages,such as: easy to realize automative control,high welding efficiency. While as for the marine electrical branch welding,in order to avoid the damage of traditional welding technology to the ship pre-coating,we must use special welding technology to replace the traditional shielded metal arc welding. Therefore,this paper studied the machine type selection,parameters selection and other aspects,proved that the arc stud welding technology can effectively improve the efficiency of welding and control the welding quality.%电弧螺柱焊接技术是一种被广泛应用的焊接方法,拥有很高的螺柱焊接效率,具有很多优点,比如:容易实现自动化控制、焊接效率高等。而对船舶电气支件焊接来说,要想避免传统焊接技术对船舶预涂层的破坏,就要采用专用的焊接技术来代替传统的焊条电弧焊。因此,本文对机器的选型、参数的选定等进行了研究,证明电弧螺柱焊接技术能够有效地提高焊接效率,控制焊接质量。

  10. Total Marrow Irradiation With RapidArc Volumetric Arc Therapy

    International Nuclear Information System (INIS)

    Purpose: To develop a volumetric arc therapy (VMAT)-total marrow irradiation (TMI) technique for patients with hematologic malignancies. Methods and Materials: VMAT planning was performed for 6 patients using RapidArc technology. The planning target volume consisted of all the bones in the body from the head to the mid-femur, excluding the extremities, except for the humerus, plus a 3.0-mm margin. The organs at risk included the lungs, heart, liver, kidneys, bowels, brain, eyes, and oral cavity. The VMAT-TMI technique consisted of three plans: the head and neck, the chest, and the pelvis, each with three 330o arcs. The plans were prescribed to ensure, at a minimum, 95% planning target volume dose coverage with the prescription dose (percentage of volume receiving dose of ≥12 Gy was 95%). The treatments were delivered and verified using MapCheck and ion chamber measurements. Results: The VMAT-TMI technique reported in the present study provided comparable dose distributions with respect to the fixed gantry linear accelerator intensity-modulated TMI. RapidArc planning was less subjective and easier, and, most importantly, the delivery was more efficient. RapidArc reduced the treatment delivery time to approximately 18 min from 45 min with the fixed gantry linear accelerator intensity-modulated TMI. When the prescription dose coverage was reduced to 85% from 95% and the mandible and maxillary structures were not included in the planning target volume as reported in a tomotherapy study, a considerable organ at risk dose reduction of 4.2-51% was observed. The average median dose for the lungs and lenses was reduced to 5.6 Gy from 7.2 Gy and 2.4 Gy from 4.5 Gy, respectively. Conclusion: The RapidArc VMAT technique improved the treatment planning, dose conformality, and, most importantly, treatment delivery efficiency. The results from our study suggest that the RapidArc VMAT technology can be expected to facilitate the clinical transition of TMI.

  11. Improving Processes of Mechanized Pulsed Arc Welding of Low-Frequency Range Variation of Mode Parameters

    Science.gov (United States)

    Saraev, Yu N.; Solodskiy, S. A.; Ulyanova, O. V.

    2016-04-01

    A new technology of low-frequency modulation of the arc current in MAG and MIG welding is presented. The technology provides control of thermal and crystallization processes, stabilizes the time of formation and crystallization of the weld pool. Conducting theoretical studies allowed formulating the basic criteria for obtaining strong permanent joints for high-duty structures, providing conditions for more equilibrium structure of the deposited metal and the smaller width of the HAZ. The stabilization of time of the formation and crystallization of the weld pool improves the formation of the weld and increases productivity in welding thin sheet metal.

  12. Development of open air silicon deposition technology by silane-free atmospheric pressure plasma enhanced chemical transport under local ambient gas control

    Science.gov (United States)

    Naito, Teruki; Konno, Nobuaki; Yoshida, Yukihisa

    2016-07-01

    Open air silicon deposition was performed by combining silane-free atmospheric pressure plasma-enhanced chemical transport and a newly developed local ambient gas control technology. The effect of air contamination on silicon deposition was investigated using a vacuum chamber, and the allowable air contamination level was confirmed to be 3 ppm. The capability of the local ambient gas control head was investigated numerically and experimentally. A safe and clean process environment with air contamination less than 1 ppm was achieved. Combining these technologies, a microcrystalline silicon film was deposited in open air, the properties of which were comparable to those of silicon films deposited in a vacuum chamber.

  13. Plasma Assisted Chemical Vapour DepositionTechnological Design Of Functional Coatings

    Directory of Open Access Journals (Sweden)

    Januś M.

    2015-06-01

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

  14. A mechanism that triggers double arcing during plasma arc cutting

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, Valerian, E-mail: nemchinsky@bellsouth.ne [Keiser University, Fort Lauderdale, FL 33309 (United States)

    2009-10-21

    Double arcing (DA) is a phenomenon when a transferred arc, flowing inside an electrically insulated nozzle, breaks into two separate arcs: one that connects the cathode and the nozzle and another that connects the nozzle and a work-piece. It is a commonly accepted opinion that the reason for DA is high voltage drop in the plasma inside the nozzle. However, the specific mechanism that triggers the DA development is not clear. In this paper, we propose such a mechanism. Dielectric films deposited inside the nozzle's orifice play the key role in this mechanism. These films are charged by ion current from plasma. A strong electric field is created inside the film and at the boundary of the film and clean metal of the nozzle. This gives rise to a thermo-field electron emission from the clean metal that borders the film. Emitted electrons are accelerated at the voltage drop between the nozzle and plasma. These electrons produce extra ions, which in turn move back to the film and additionally charge it. This sequence of events leads to explosive instability if the voltage drop inside the nozzle is high enough. Experiments to check the proposed mechanism are suggested.

  15. Development of a new post-combustion technology at the SAM Neuves-Maisons electric arc furnace; Developpement d`un nouveau procede de postcombustion au four a arc de SAM Neuves-Maisons

    Energy Technology Data Exchange (ETDEWEB)

    Cadet, R.; Le Coq, X. [IRSID (Country unknown/Code not available); Colsenet, S.; Porzucek, F. [Acieries, 54 - Neuves-Maisons (France)

    1998-04-01

    In order ro increase its productivity, SAM Neuves-Maisons has started, in collaboration with Irsid, a post-combustion installation. 800 00 tons/year of wire rod, mainly for reinforced concrete, are produced from scrap. Melting is ensured by a 160-ton, 80 MVA furnace, equipped with cooled panels and roof, an oxygen and carbon injection device, an excentric bottom tapping. The oxygen is injected by three water cooled lances located in the electric arc furnace roof. The efficiency of post-combustion is increased by limiting as much as possible the air intake through the gate and the vessel/roof joint, and by the use of a dynamic regulation of the fumes in the EAF, so as to keep the pressure of the vessel close to about 0 Pa. The injection process was defined in order to adjust the non-burned emissions (CO and H{sub 2}), which were measured by fume analysis during preliminary trials. For an increase of oxygen consumption of 4.8 m{sup 3}/ton billet, the post-combustion allows to obtain a decrease of: electric consumption: 19 kWh/ton billet (4.5%); power-on time: 2.2 min (4,4%); tap-to-tap time: 2.7 min (3.5 %). We obtained an oxygen replacement ratio of 4.0 kWh/m{sup 3} O{sub 2}, i.e. an average thermal yield of 60 %. (authors) 3 refs.

  16. Studies of steered arc motion and macroparticle production in PVD processing

    Energy Technology Data Exchange (ETDEWEB)

    Craven, A.L

    2000-03-01

    During the past decade the production industry has constantly strived to improve performance and cut costs, this has been aided by the development of high performance tools. The advancement of these tools has been accomplished by the application of hard wearing, low friction, coatings. A key process in the production of such coatings is Physical Vapour Deposition (PVD). Interest in such thin films has led to much research effort, both academic and industrial, being devoted to the area. In order that these advancements in technology continue, research into the fundamental aspects of PVD is required. This thesis describes research and experimental studies which have been performed to study the effect of 'steering' an electric arc on various aspects of its behaviour. 'Steering' of the arc is achieved by applying external magnetic fields which allow the guidance of the path of the arc. Work by earlier authors has aimed to control the arc more fully. The research presented here is based of a novel electromagnetic three coil steering array of cylindrical geometry. With such coils it is possible to vary the field profiles to a greater degree than has been previously achieved, permitting a greater range of steering arrangements/fields to be applied. The research presented is divided into two distinct areas: Firstly a number of experiments were performed to assess the effectiveness of the new steering coils on the motion of the arc. A personal computer was used here along with new arc motion monitoring electronics. This enabled the simultaneous measurement of the orbital transit times and also the degree of travel perpendicular to the steered direction of motion of the arc, as it traversed the surface of the cathode. Such information was then used to produce values for standard deviation of the arc from its steered path, velocity of the arc and a diffusion constant related to the motion of the are. Such values then allowed evaluation of the stochastic

  17. Studies of steered arc motion and macroparticle production in PVD processing

    International Nuclear Information System (INIS)

    During the past decade the production industry has constantly strived to improve performance and cut costs, this has been aided by the development of high performance tools. The advancement of these tools has been accomplished by the application of hard wearing, low friction, coatings. A key process in the production of such coatings is Physical Vapour Deposition (PVD). Interest in such thin films has led to much research effort, both academic and industrial, being devoted to the area. In order that these advancements in technology continue, research into the fundamental aspects of PVD is required. This thesis describes research and experimental studies which have been performed to study the effect of 'steering' an electric arc on various aspects of its behaviour. 'Steering' of the arc is achieved by applying external magnetic fields which allow the guidance of the path of the arc. Work by earlier authors has aimed to control the arc more fully. The research presented here is based of a novel electromagnetic three coil steering array of cylindrical geometry. With such coils it is possible to vary the field profiles to a greater degree than has been previously achieved, permitting a greater range of steering arrangements/fields to be applied. The research presented is divided into two distinct areas: Firstly a number of experiments were performed to assess the effectiveness of the new steering coils on the motion of the arc. A personal computer was used here along with new arc motion monitoring electronics. This enabled the simultaneous measurement of the orbital transit times and also the degree of travel perpendicular to the steered direction of motion of the arc, as it traversed the surface of the cathode. Such information was then used to produce values for standard deviation of the arc from its steered path, velocity of the arc and a diffusion constant related to the motion of the are. Such values then allowed evaluation of the stochastic model of arc motion

  18. Peek Arc Consistency

    CERN Document Server

    Bodirsky, Manuel

    2008-01-01

    This paper studies peek arc consistency, a reasoning technique that extends the well-known arc consistency technique for constraint satisfaction. In contrast to other more costly extensions of arc consistency that have been studied in the literature, peek arc consistency requires only linear space and quadratic time and can be parallelized in a straightforward way such that it runs in linear time with a linear number of processors. We demonstrate that for various constraint languages, peek arc consistency gives a polynomial-time decision procedure for the constraint satisfaction problem. We also present an algebraic characterization of those constraint languages that can be solved by peek arc consistency, and study the robustness of the algorithm.

  19. Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

    International Nuclear Information System (INIS)

    This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace

  20. Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, W.C. [ed.

    1995-05-31

    This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace.

  1. Electric arc hydrogen heaters

    International Nuclear Information System (INIS)

    The experimental data on the electric arc burning in hydrogen are presented. Empirical and semiempirical dependences for calculating the arc characteristics are derived. An engineering method of calculating plasma torches for hydrogen heating is proposed. A model of interaction of a hydrogen arc with a gas flow is outlined. The characteristics of plasma torches for heating hydrogen and hydrogen-bearing gases are described. (author)

  2. Recent ARC developments: Through modularity to interoperability

    Energy Technology Data Exchange (ETDEWEB)

    Smirnova, O; Cameron, D; Ellert, M; Groenager, M; Johansson, D; Kleist, J [NDGF, Kastruplundsgade 22, DK-2770 Kastrup (Denmark); Dobe, P; Joenemo, J; Konya, B [Lund University, Experimental High Energy Physics, Institute of Physics, Box 118, SE-22100 Lund (Sweden); Fraagaat, T; Konstantinov, A; Nilsen, J K; Saada, F Ould; Qiang, W; Read, A [University of Oslo, Department of Physics, P. O. Box 1048, Blindern, N-0316 Oslo (Norway); Kocan, M [Pavol Jozef Safarik University, Faculty of Science, Jesenna 5, SK-04000 Kosice (Slovakia); Marton, I; Nagy, Zs [NIIF/HUNGARNET, Victor Hugo 18-22, H-1132 Budapest (Hungary); Moeller, S [University of Luebeck, Inst. Of Neuro- and Bioinformatics, Ratzeburger Allee 160, D-23538 Luebeck (Germany); Mohn, B, E-mail: oxana.smirnova@hep.lu.s [Uppsala University, Department of Physics and Astronomy, Div. of Nuclear and Particle Physics, Box 535, SE-75121 Uppsala (Sweden)

    2010-04-01

    The Advanced Resource Connector (ARC) middleware introduced by NorduGrid is one of the basic Grid solutions used by scientists worldwide. While being well-proven in daily use by a wide variety of scientific applications at large-scale infrastructures like the Nordic DataGrid Facility (NDGF) and smaller scale projects, production ARC of today is still largely based on conventional Grid technologies and custom interfaces introduced a decade ago. In order to guarantee sustainability, true cross-system portability and standards-compliance based interoperability, the ARC community undertakes a massive effort of implementing modular Web Service (WS) approach into the middleware. With support from the EU KnowARC project, new components were introduced and the existing key ARC services got extended with WS technology based standard-compliant interfaces following a service-oriented architecture. Such components include the hosting environment framework, the resource-coupled execution service, the re-engineered client library, the self-healing storage solution and the peer-to-peer information system, to name a few. Gradual introduction of these new services and client tools into the production middleware releases is carried out together with NDGF and thus ensures a smooth transition to the next generation Grid middleware. Standard interfaces and modularity of the new component design are essential for ARC contributions to the planned Universal Middleware Distribution of the European Grid Initiative.

  3. Recent ARC developments: Through modularity to interoperability

    International Nuclear Information System (INIS)

    The Advanced Resource Connector (ARC) middleware introduced by NorduGrid is one of the basic Grid solutions used by scientists worldwide. While being well-proven in daily use by a wide variety of scientific applications at large-scale infrastructures like the Nordic DataGrid Facility (NDGF) and smaller scale projects, production ARC of today is still largely based on conventional Grid technologies and custom interfaces introduced a decade ago. In order to guarantee sustainability, true cross-system portability and standards-compliance based interoperability, the ARC community undertakes a massive effort of implementing modular Web Service (WS) approach into the middleware. With support from the EU KnowARC project, new components were introduced and the existing key ARC services got extended with WS technology based standard-compliant interfaces following a service-oriented architecture. Such components include the hosting environment framework, the resource-coupled execution service, the re-engineered client library, the self-healing storage solution and the peer-to-peer information system, to name a few. Gradual introduction of these new services and client tools into the production middleware releases is carried out together with NDGF and thus ensures a smooth transition to the next generation Grid middleware. Standard interfaces and modularity of the new component design are essential for ARC contributions to the planned Universal Middleware Distribution of the European Grid Initiative.

  4. Sol–gel deposited ceria thin films as gate dielectric for CMOS technology

    Indian Academy of Sciences (India)

    Anil G Khairnar; Ashok M Mahajan

    2013-04-01

    In this work, cerium oxide thin films were prepared using cerium chloride heptahydrate, ethanol and citric acid as an additive by sol–gel spin-coating technique and further characterized to study the various properties. Chemical composition of deposited films has been analysed by FTIR which shows existence of CeO2. The samples have been optically characterized using ellipsometry to find refractive index of 2.18 and physical thickness which is measured to be 5.56 nm. MOS capacitors were fabricated by depositing aluminum (Al) metal using the thermal evaporation technique on the top of CeO2 thin films. Capacitance–voltage measurement was carried out to calculate the dielectric constant, flat-band voltage shift of 18.92, 0.3–0.5V, respectively and conductance–voltage study was carried out to determine the Dit of 1.40 × 1013 eV-1 cm-2 at 1MHz.

  5. Characteristics of coal from the deposit 'Suvodol' and technological parameters for briquetting (Macedonia)

    International Nuclear Information System (INIS)

    The use of small class coat as well as the lack of formed fuel needed for the industry and for the consumer goods has been a long lasting problem, and a challenge for the researchers of the Republic of Macedonia. For that purpose, all-inclusive analysis of the quality of the coals in Macedonia, their reserves and technical characteristics, as well as analysis of the petrographic structure were made. Classification of the coal deposits and the research for the possibility of making briquettes was done, too. All the analysis brought to conclusion that the deposit Suvodol should be selected as the biggest in the stage of exploitation with mine, thermo-power station and personnel equipment, too. Standard methods were used for the researches without connective means and the achieved results were mutually correlated. Technical-economic verification is necessary in the further process. (Author)

  6. Coal characteristics from 'Priskupshtina' deposit and technological parameters for briquetting (Macedonia)

    International Nuclear Information System (INIS)

    The use of small class coal as well as the lack of formed fuel needed for the industry and for the consumer goods has been a long lasting problem, and a challenge for the researchers of the Republic of Macedonia. For that purpose, all-inclusive analysis of the quality of the coals in Macedonia, their reserves and technical characteristics, as well as analysis of the petrographic structure were made. Classification of the deposits and the research for the possibility of making briquettes was done, too. Laboratory investigations in the coal deposit 'Priskupshtina' were carried out. The analysis of the coal briquetting show that the expected results in coordination with the required standards were not obtained. Spatially the results from the coal calorific value, its hardness and atmospheric resistance. Standard methods were used for the researches without connective means and the achieved results were mutually correlated. Technical-economic verification is necessary in the further process. (Author)

  7. Arc generation from sputtering plasma-dielectric inclusion interactions

    International Nuclear Information System (INIS)

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al2O3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect density, and the intensity of the optical emission from the arcing plasma indicates that the critical aluminum oxide inclusion area for arcing is 0.22±0.1 mm2 when the sputtering plasma sheath dark-space λd, is 0.51 mm. Inclusions with areas greater than this critical value readily induce arcing and macroparticle ejection during sputtering. Inclusions below this critical size do not cause arcing or macroparticle ejection. When the inclusion major axis is longer than 2λd and lies perpendicular to the sputter erosion track tangent, the arcing activity increases significantly over the case where the inclusion major axis lies parallel to the erosion track tangent

  8. Development of a new post-combustion technology at SAM Neuves-Maisons electric arc furnace; Developpement d`un nouveau procede de post-combustion au four a arc de SAM Neuves-Maisons

    Energy Technology Data Exchange (ETDEWEB)

    Le Coq, X.; Cadet, R. [IRSID, Institut de Recherches Siderurgie, 57 - Maizieres-les-Metz (France); Colsenet, S.; Porzucek, F. [SAM, Societe des Aciers d`Armature pour le Beton, 54 - Neuves-Maisons, (France)

    1997-11-01

    In order to increase the productivity of the EAF, SAM Neuves-Maisons and Irsid have developed a technology for post-combustion, based on oxygen injection during the scrap melting phase. Oxygen is injected through three lances placed in the furnace roof. With post-combustion, used industrially since July 1995, the objective of productivity has been attained through a decrease of electricity consumption of 25 kWh/t billets for an increase of 5 Nm{sup 3} O{sub 2} per ton. (authors)

  9. In situ derivation of sulfur activated TiO{sub 2} nano porous layers through pulse-micro arc oxidation technology

    Energy Technology Data Exchange (ETDEWEB)

    Bayati, M.R., E-mail: mbayati@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States); School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P.O. Box 16845-161, Tehran (Iran, Islamic Republic of); Golestani-Fard, F. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P.O. Box 16845-161, Tehran (Iran, Islamic Republic of); Center of Excellence for Advanced Materials, Iran University of Science and Technology, P.O. Box 16845-195, Tehran (Iran, Islamic Republic of); Moshfegh, A.Z. [Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of); Molaei, Roya [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, P.O. Box 16845-161, Tehran (Iran, Islamic Republic of)

    2011-10-15

    Highlights: {yields} S-TiO{sub 2} layers were grown by MAO technique under pulse current for the first time. {yields} Effect of growth parameters on chemical composition, topography, and morphology of the layers was studied. {yields} A correlation between photocatalytic performance and growth conditions was proposed. -- Abstract: Micro arc oxidation technique, as a facile and efficient process, was employed to grow sulfur doped titania porous layers. This research sheds light on the photocatalytic performance of the micro arc oxidized S-TiO{sub 2} nano-porous layers fabricated under pulse current. Morphological and topographical studies, performed by SEM and AFM techniques, revealed that increasing the frequency and/or decreasing the duty cycle resulted in formation of finer pores and smoother surfaces. XRD and XPS results showed that the layers consisted of anatase and rutile phases whose fraction was observed to change depending on the synthesis conditions. The highest anatase relative content was obtained at the frequency of 500 Hz and the duty cycle of 5%. Furthermore, photocatalytic activity of the layers was examined by measuring the decomposition rate of methylene blue under both ultraviolet and visible photo irradiations. Maximum photodegradation reaction rate constants over the pulse-grown S-TiO{sub 2} layers were respectively measured as 0.0202 and 0.0110 min{sup -1} for ultraviolet and visible irradiations.

  10. Fabrication of Nickel Nanotube Using Anodic Oxidation and Electrochemical Deposition Technologies and Its Hydrogen Storage Property

    Directory of Open Access Journals (Sweden)

    Yan Lv

    2016-01-01

    Full Text Available Electrochemical deposition technique was utilized to fabricate nickel nanotubes with the assistance of AAO templates. The topography and element component of the nickel nanotubes were characterized by TEM and EDS. Furthermore, the nickel nanotube was made into microelectrode and its electrochemical hydrogen storage property was studied using cyclic voltammetry. The results showed that the diameter of nickel nanotubes fabricated was around 20–100 mm, and the length of the nanotube could reach micron grade. The nickel nanotubes had hydrogen storage property, and the hydrogen storage performance was higher than that of nickel powder.

  11. Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm2 in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine–saccharose as releasing agent, which were previously covered with evaporated carbon layers ∼1μg/cm2 in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4 for the 197Au− (∼9MeV, ∼1μA) and 63Cu− (∼9MeV, ∼1μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (ID/IG) measured by the Raman spectroscopy is 0.78

  12. Synthesis of multiwalled carbon nanotube from different grades of carbon black using arc discharge method

    Science.gov (United States)

    Arora, Neha; Sharma, N. N.

    2016-04-01

    This paper describes the synthesis of nanotube from different grades (Tread * A(non-ASTM), N134,N121,N660 and N330)of carbon black using DC arc discharge method at 40A current for 60sec. Carbon black samples of different grades were procured from industry (Aditya Birla Science and Technology Limited, India). Scanning Electron Micrographs (SEM) of the deposited carbon nanostructures suggests that MWCNTs are formed at 40A and for a minimal exposure time of 60sec.The result formed indicates the N330 grade of carbon black gets converted to MWCNTs (Multiwall Carbon nanotube) as compared to other grades.

  13. Technological Possibilities of Si:H Thin Film Deposition with Embedded Cubic Mg2Si Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Galkin, N.G.; Galkin, K.N.; Chernev, I.M.; Fajgar, Radek; Stuchlíková, The-Ha; Remeš, Zdeněk; Stuchlík, Jiří

    2013-01-01

    Roč. 10, č. 12 (2013), s. 1712-1716. ISSN 1862-6351. [Asia-Pacific Conference on Green Technology with Silicides and Related Materials (APAC-SILICIDE 2013) /3./. Tsukuba, Ibaraki, 27.07.2013-29.07.2013] R&D Projects: GA ČR GA13-25747S Grant ostatní: MŠMT(CZ) LH12236; RFB(RU) 13-02-00046 Institutional support: RVO:67985858 ; RVO:68378271 Keywords : Mg2Si * nanoparticles * technology Subject RIV: CA - Inorganic Chemistry; BM - Solid Matter Physics ; Magnetism (FZU-D)

  14. Tokamak ARC damage

    International Nuclear Information System (INIS)

    Tokamak fusion reactors will have large plasma currents of approximately 10 MA with hundreds of megajoules stored in the magnetic fields. When a major plasma instability occurs, the disruption of the plasma current induces voltage in the adjacent conducting structures, giving rise to large transient currents. The induced voltages may be sufficiently high to cause arcing across sector gaps or from one protruding component to another. This report reviews a tokamak arcing scenario and provides guidelines for designing tokamaks to minimize the possibility of arc damage

  15. Potential of direct metal deposition technology for manufacturing thick functionally graded coatings and parts for reactors components

    International Nuclear Information System (INIS)

    Direct metal deposition (DMD) is an automated 3D deposition process arising from laser cladding technology with co-axial powder injection to refine or refurbish parts. Recently DMD has been extended to manufacture large-size near-net-shape components. When applied for manufacturing new parts (or their refinement), DMD can provide tailored thermal properties, high corrosion resistance, tailored tribology, multifunctional performance and cost savings due to smart material combinations. In repair (refurbishment) operations, DMD can be applied for parts with a wide variety of geometries and sizes. In contrast to the current tool repair techniques such as tungsten inert gas (TIG), metal inert gas (MIG) and plasma welding, laser cladding technology by DMD offers a well-controlled heat-treated zone due to the high energy density of the laser beam. In addition, this technology may be used for preventative maintenance and design changes/up-grading. One of the advantages of DMD is the possibility to build functionally graded coatings (from 1 mm thickness and higher) and 3D multi-material objects (for example, 100 mm-sized monolithic rectangular) in a single-step manufacturing cycle by using up to 4-channel powder feeder. Approved materials are: Fe (including stainless steel), Ni and Co alloys, (Cu,Ni 10%), WC compounds, TiC compounds. The developed coatings/parts are characterized by low porosity (<1%), fine microstructure, and their microhardness is close to the benchmark value of wrought alloys after thermal treatment (Co-based alloy Stellite, Inox 316L, stainless steel 17-4PH). The intended applications concern cooling elements with complex geometry, friction joints under high temperature and load, light-weight mechanical support structures, hermetic joints, tubes with complex geometry, and tailored inside and outside surface properties, etc

  16. Potential of direct metal deposition technology for manufacturing thick functionally graded coatings and parts for reactors components

    Science.gov (United States)

    Thivillon, L.; Bertrand, Ph.; Laget, B.; Smurov, I.

    2009-03-01

    Direct metal deposition (DMD) is an automated 3D deposition process arising from laser cladding technology with co-axial powder injection to refine or refurbish parts. Recently DMD has been extended to manufacture large-size near-net-shape components. When applied for manufacturing new parts (or their refinement), DMD can provide tailored thermal properties, high corrosion resistance, tailored tribology, multifunctional performance and cost savings due to smart material combinations. In repair (refurbishment) operations, DMD can be applied for parts with a wide variety of geometries and sizes. In contrast to the current tool repair techniques such as tungsten inert gas (TIG), metal inert gas (MIG) and plasma welding, laser cladding technology by DMD offers a well-controlled heat-treated zone due to the high energy density of the laser beam. In addition, this technology may be used for preventative maintenance and design changes/up-grading. One of the advantages of DMD is the possibility to build functionally graded coatings (from 1 mm thickness and higher) and 3D multi-material objects (for example, 100 mm-sized monolithic rectangular) in a single-step manufacturing cycle by using up to 4-channel powder feeder. Approved materials are: Fe (including stainless steel), Ni and Co alloys, (Cu,Ni 10%), WC compounds, TiC compounds. The developed coatings/parts are characterized by low porosity (joints under high temperature and load, light-weight mechanical support structures, hermetic joints, tubes with complex geometry, and tailored inside and outside surface properties, etc.

  17. Influence of the vacuum-arc source configuration and arc discharge parameters on the evolution and location of arc spots on the cathode surface

    Directory of Open Access Journals (Sweden)

    J. Walkowicz

    2009-12-01

    Full Text Available Purpose: The paper presents investigations of the evolution, structure and location of arc spots on the cathode frontal surfaces of two types of industrial arc sources.Design/methodology/approach: The temporal behaviour of cathode spots was recorded with the use of a fast CCD camera. The experiments were performed at four values of arc current, nine compositions of the process atmosphere N2+C2H2 and three pressure ranges of the process atmosphere.Findings: The analysis of the recorded pictures revealed the fine structure of the arc discharge for the investigated range of process conditions. Both temporal and spatial behaviour of cathode spots were different for both investigated arc sources. The correspondence between radial distributions of the cathode spots on the cathode surface and radial distribution of plasma flow elements analysed in the volume of the vacuum chamber was revealed.Research limitations/implications: The paper show experimental methodology that can be used for the research of the specificity of cathode spots movement on the cathodes made from different materials.Originality/value: The originality of the research presented in the paper consists in assigning overall correlation between vacuum-arc source configuration and parameters of vacuum-arc discharge – on the one hand, and space-time behaviour of the arc spots during their movement on the circular cathode surface and radial distribution of excited and ionized atoms of the cathode material in the deposition chamber – on the other.

  18. Quarterly Report: Microchannel-Assisted Nanomaterial Deposition Technology for Photovoltaic Material Production

    Energy Technology Data Exchange (ETDEWEB)

    Palo, Daniel R.

    2011-04-26

    Quarterly report to ITP for Nanomanufacturing program. Report covers FY11 Q2. The primary objective of this project is to develop a nanomanufacturing process which will reduce the manufacturing energy, environmental discharge, and production cost associated with current nano-scale thin-film photovoltaic (PV) manufacturing approaches. The secondary objective is to use a derivative of this nanomanufacturing process to enable greener, more efficient manufacturing of higher efficiency quantum dot-based photovoltaic cells now under development. The work is to develop and demonstrate a scalable (pilot) microreactor-assisted nanomaterial processing platform for the production, purification, functionalization, and solution deposition of nanomaterials for photovoltaic applications. The high level task duration is shown. Phase I consists of a pilot platform for Gen II PV films along with parallel efforts aimed at Gen III PV quantum dot materials. Status of each task is described.

  19. Molten-Metal Droplet Deposition on a Moving Substrate in Microgravity: Aiding the Development of Novel Technologies for Microelectronic Assembly

    Science.gov (United States)

    Megaridis, C. M.; Bayer, I. S.; Poulikakos, D.; Nayagam, V.

    2002-01-01

    Driven by advancements in microelectronics manufacturing, this research investigates the oblique (non-axisymmetric) impact of liquid-metal droplets on flat substrates. The problem of interest is relevant to the development of the novel technology of on-demand dispension (printing) of microscopic solder deposits for the surface mounting of microelectronic devices. The technology, known as solder jetting, features on-demand deposition of miniature solder droplets (30 to 120 microns in diameter) in very fine, very accurate patterns using techniques analogous to those developed for the ink-jet printing industry. Despite its promise, severe limitations exist currently with regards to the throughput rates of the technology; some of these limitations are largely due to the lack of the capability for reliable prediction of solder bump positioning and shapes, especially under ballistic deposition conditions where the droplet impact phenomena are inherently three-dimensional. The study consists of a theoretical and an experimental component. The theoretical work uses a finite element formulation to simulate numerically the non-axisymmetric (3-D) fluid mechanics and heat transfer phenomena of a liquid solder droplet impacting at an angle alpha on a flat substrate. The work focuses on the pre-solidification regime. The modeling of the most challenging fluid mechanics part of the process has been completed successfully. It is based upon the full laminar Navier-Stokes equations employing a Lagrangian frame of reference. Due to the large droplet deformation, the surface (skin) as well as the volumetric mesh have to be regenerated during the calculations in order to maintain the high accuracy of the numerical scheme. The pressure and velocity fields are then interpolated on the newly created mesh. The numerical predictions are being tested against experiments, for cases where wetting phenomena are not important. For the impact parameters used in the example shown (We = 2.38, Fr

  20. Vacuum arc anode phenomena

    International Nuclear Information System (INIS)

    A brief review of anode phenomena in vacuum arcs is presented. Discussed in succession are: the transition of the arc into the anode spot mode; the temperature of the anode before, during and after the anode spot forms; and anode ions. Characteristically the anode spot has a temperature of the order of the atmospheric boiling point of the anode material and is a copious source of vapor and energetic ions. The dominant mechanism controlling the transition of the vacuum arc into the anode spot mode appears to depend upon the electrode geometry, the electrode material, and the current waveform of the particular vacuum arc being considered. Either magnetic constriction in the gap plasma or gross anode melting can trigger the transition; indeed, a combination of the two is a common cause of anode spot formation

  1. The investigation of carbon nitride films prepared at various arc currents by vacuum cathode arc method

    International Nuclear Information System (INIS)

    The carbon nitride films have been prepared in the arc currents range of 20-60 A at the Ar/N2 atmosphere of 50/400 sccm by the vacuum cathode arc deposition method. The properties of the films were characterized by x-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and nanoindentation. The N concentration showed a maximum of 35 at% at 20 A and decreased gradually with the arc currents. The films below 40 A consisted of linear polymeric-like component and sp2 graphitic cluster. With the increasing of the arc current from 20 to 40 A, the ID/IG rose and the photoluminescence (PL) fell gradually, which resulted from the development of the sp2 graphitic phase and the decrease of the polymeric-like phase. As a result, the CC bonds increased and sp3CN and sp2CN decreased. Above 40 A, with the increasing of arc currents, ID/IG fell and the PL increased gradually, which reflected the decreasing of sp2 graphitic phase and the modification of C and N atoms in sp2 cluster. The CC bonds and sp3CN fell and the sp2CN rose. The nanohardness of films showed increasing tendency with the arc currents. The variation of the relative ratio and the average energy of N-containing species and C-containing species at the atmosphere would be responsible for the change in the properties of films. (author)

  2. Implementation of new Information Technologies in bank information system based on deposit information system

    OpenAIRE

    Dimitrovski, Igor

    2016-01-01

    Change in the banking business model from product orientation to client orientation is the main cause for the appearance of the need for modernisation and transformation of the banking IS in order to offer the customer a comprehensive range of personalised banking products and services. From a technological point of view, the solution lies in the introduction of service-oriented architecture and business process management systems. The first part of the master's thesis presents the reasons an...

  3. Single-Arc IMRT?

    International Nuclear Information System (INIS)

    The idea of delivering intensity-modulated radiation therapy (IMRT) with a multileaf collimator in a continuous dynamic mode during a single rotation of the gantry has recently gained momentum both in research and industry. In this note we investigate the potential of this Single-Arc IMRT technique at a conceptual level. We consider the original theoretical example case from Brahme et al that got the field of IMRT started. Using analytical methods, we derive deliverable intensity 'landscapes' for Single-Arc as well as standard IMRT and Tomotherapy. We find that Tomotherapy provides the greatest flexibility in shaping intensity landscapes and that it allows one to deliver IMRT in a way that comes close to the ideal case in the transverse plane. Single-Arc and standard IMRT make compromises in different areas. Only in relatively simple cases that do not require substantial intensity modulation will Single-Arc be dosimetrically comparable to Tomotherapy. Compared with standard IMRT, Single-Arc could be dosimetrically superior in certain cases if one is willing to accept the spreading of low dose values over large volumes of normal tissue. In terms of treatment planning, Single-Arc poses a more challenging optimization problem than Tomotherapy or standard IMRT. We conclude that Single-Arc holds potential as an efficient IMRT technique especially for relatively simple cases. In very complex cases, Single-Arc may unduly compromise the quality of the dose distribution, if one tries to keep the treatment time below 2 min or so. As with all IMRT techniques, it is important to explore the tradeoff between plan quality and the efficiency of its delivery carefully for each individual case. (note)

  4. ALICE - ARC integration

    OpenAIRE

    Anderlik, Csaba; Gregersen, Anders Rhod; Kleist, Josva; Peters, Andreas; Siaz, Pablo

    2007-01-01

    AliEn or Alice Environment is the Gridware developed and used within the ALICE collaboration for storing and processing data in a distributed manner. ARC (Advanced Resource Connector) is the Grid middleware deployed across the Nordic countries and gluing together the resources within the Nordic Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructur...

  5. High efficiency infrared antireflection coatings (ARCs) for space optics

    Science.gov (United States)

    Nagendra, C. L.; Thutupalli, G. K. M.; Mohan, S.

    1989-05-01

    The development of non-quarter-wave IR ARCs for the Ge optics of space electrooptic hardware is described. A novel design-optimization method is applied in which the geometrical thicknesses of the ARC layers are calculated analytically (as explained by Nagendra, 1987). Two ARCs are developed: a three-layer system (ThF4/Ge/ThF4) for use at 7-12 microns and a two-layer system (CdTe/CdSe) for 14-16 microns. The ARCs are deposited in a vacuum-evaporation facility and subjected to optical and durability testing. The results are presented in graphs, and it is demonstrated that the ARCs are durable and transparent over the desired wavelength range and have spectral transmittance characteristics in good agreement with the theoretically predicted values.

  6. Characterization of Cr-O cermet solar selective coatings deposited by using direct-current magnetron sputtering technology

    International Nuclear Information System (INIS)

    Cr-O (Cr-CrO) cermet solar selective coatings with a double cermet layer film structure were prepared by using a special direct-current (dc) magnetron sputtering technology. The typical film structure from the surface to the bottom substrate was an Al2O3 anti-reflection layer on a double Cr-O cermet layer on an Al metal infrared reflection layer. The deposited Cr-O cermet solar selective coating had an absorptance of α = 0.93 - 0.95 and an emittance of ε = 0.09 - 0.10(100 .deg. C). The absorption layers of the Cr-O cermet coatings deposited on glass and silicon substrates were identified as being amorphous by using X-ray diffraction (XRD). Atomic force microscopy (AFM) showed that Cr-O cermet layers were very smooth and that their grain sizes were very small. The result of thermal stability test showed that the Cr-O cermet solar selective coating was stable for use at temperatures of under 400 .deg. C.

  7. Microstructure and Performances of the WC-10Co4Cr coatings deposited by laser hybrid plasma spraying technology

    International Nuclear Information System (INIS)

    In this paper, WC-10Co4Cr coatings were deposited by the laser hybrid plasma spraying (LHPS) technology on 38CrMoAl substrates. Microstructure and tribological properties of the coatings were studied using optical microscopy, X-ray diffraction, scanning electron microscope, SRV friction and wear testing. The results indicated that the microstructures and properties of the laser hybrid plasma spraying WC-10Co4Cr coatings changed with the laser power. When the laser power was 2100-2500 W, the coating had good adherence with the substrate, compact microstructures, high bonding strength, low friction coefficient and good anti-wear performance. The wear mechanism of the LHPS WC-10Co4Cr coating is mild scratching and plastic deformation. (authors)

  8. MeCrAl coatings obtained by arc PVD and pack cementation processes on nickel base superalloys

    International Nuclear Information System (INIS)

    The paper presents the results of researches on obtaining and structure of high temperature resistance coatings on superalloys. The coatings were deposited on nickel and nickel base superalloys in two stages. During the first stage, the NiCr and NiCrHf coatings were obtained by arc-PVD method. Basic technology, bias, arc current, rotation, parameters of deposition of NiCr and MeCrHf coatings were defined. The high efficiency of deposition of both single and two sources was observed. The targets were made by vacuum melting and machining. An influence of targets chemical composition on coating structure and chemical coatings composition was described. The second stage was made by pack cementation HTLA (high temperature low activity) on 1323 K chromoaluminizing process. These arc-PVD and diffusion (pack cementation) connected processes permitted to obtain MeCrAl and MeCrAlHf type of coatings. The morphology, structure and microchemical composition were characterized by scanning electron microscopy, X-ray microanalysis, energy dispersive X-ray spectroscopy and X-ray diffraction methods. (orig.)

  9. Computer simulation to arc spraying

    Institute of Scientific and Technical Information of China (English)

    梁志芳; 李午申; 王迎娜

    2004-01-01

    The arc spraying process is divided into two stages: the first stage is atomization-spraying stream (ASS) and the second one is spraying deposition (SD). Then study status is described of both stages' physical model and corresponding controlling-equation. Based on the analysis of study status, the conclusion as follows is got. The heat and mass transfer models with two or three dimensions in ASS stage should be established to far deeply analyses the dynamical and thermal behavior of the overheat droplet. The statistics law of overheated droplets should be further studied by connecting simulation with experiments. More proper validation experiments should be designed for flattening simulation to modify the models in SD stage.

  10. Acidic deposition: State of science and technology. Report 11. Historical changes in surface-water acid-base chemistry in response to acidic deposition. Final report

    International Nuclear Information System (INIS)

    The objectives of the analyses reported in the State of Science report are to: identify the lake and stream populations in the United States that have experienced chronic changes in biologically significant constituents of surface water chemistry (e.g. pH, Al) in response to acidic deposition; quantify biologically meaningful historical changes in chronic surface water chemistry associated with acidic deposition, with emphasis on ANC, pH, and Al; estimate the proportion of lakes nor acidic that were not acidic in pre-industrial times; estimate the proportional response of each of the major chemical constituents that have changed in response to acidic deposition using a subset of statistically selected Adirondack lakes for which paleolimnological reconstructions of pre-industrial surface water chemistry have been performed; evaluate and improve, where appropriate and feasible, empirical models of predicting changes in ANC; and evaluate the response of seepage lakes to acidic deposition

  11. Local deposition of Copper on Aluminum based MWT Back Contact Foil using Cold Spray Technology

    Energy Technology Data Exchange (ETDEWEB)

    Goris, M.J.A.A.; Bennett, I.J.; Eerenstein, W. [ECN Solar Energy, Petten (Netherlands)

    2013-11-15

    MWT cell and module technology has been shown to result in modules with up to 5% higher power output than H-pattern modules and to be suitable for use with thin and fragile cells. In this study, the use of a low cost conductive back-sheet with aluminium as the current carrier in combination with locally applied copper (5 to 30 {mu}m) using the cold spray method is benchmarked against a standard PVF-PET-copper foil in 2 x 2 cell modules. Cell to module losses and reliability during climate chamber tests according to IEC61215 ed. 2, are comparable to module made with the standard foil. Optimizing the cold spray process can result in a cost reduction of more than a factor 10 of the current carrying component, when compared to a full copper conductive back-sheet foil.

  12. Low and Non-waste Process Technology: The Development of a High Calorific Fuel Gas from Waste Oil Using Electric Arc Cracking.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Hyung; Kim, Jeong Guk; Kim, In Tae; Cho, Kwang Hun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Oh, Yang Hwan; Kim, Su Joung [Teko Environment Company Limited, Seoul (Korea, Republic of); Seo, Yong Chil; Song, Geum Ju; Sim, Sang Geul [Yonsei University, Seoul (Korea, Republic of)

    1997-12-01

    A laboratory scale unit(5kg/hr) of high calorific fuel gas generator from waste oil by electric arc cracking is developed and made test runs with the collected waste oil at car repair shops to observe its performance and acceptability for various operating conditions. About 60-65% of total amount of generated gas is composed of hydrogen, acetylene and ethylene. Total calorific value of the product gas shows about 10,000 kcal/kg and it is acceptable to use for fuel gas in the industry. The optimum temperature of waste oil for the production of higher calorific fuel gas is found to be 40 deg C. The average size of soot collected from the equipment is 0.3 {mu}m and it could be utilized as carbon black after detail analysis. The generation rate of product fuel gas is 100 - 140 L/kWh and the economic assessment shows that the equipment cost could be recovered within two years. Further studies on scale-up of the equipment and the development of an new electrode system having less consumption but higher stability are required. 18 refs., 13 tabs., 15 figs. (author)

  13. Modeling of Arc Force in Plasma Arc Welding

    Institute of Scientific and Technical Information of China (English)

    GAO Zhonglin; HU Shengsun; YIN Fengliang; WANG Rui

    2008-01-01

    A three. dimensional mathematical model for the transferred-type argon arc was developed to describe arc force on the anode surface. The software ANSYS was employed to solve the model. The model includes a part of torch and tungsten electrode to achieve m ore reasonable results. The arc temperature and flow fields were derived. And the influences of welding parameters on arc force were also studied. The simulated results show that arc pressure at the anode are dependent on the welding current, plasma gas flow rate and electrode neck-in, while not sensitive to arc length.

  14. Arc generation from sputtering plasma-dielectric inclusion interactions

    CERN Document Server

    Wickersham, C E J; Fan, J S

    2002-01-01

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al sub 2 O sub 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect...

  15. ALICE-ARC integration

    International Nuclear Information System (INIS)

    AliEn or Alice Environment is the Grid middleware developed and used within the ALICE collaboration for storing and processing data in a distributed manner. ARC (Advanced Resource Connector) is the Grid middleware deployed across the Nordic countries and gluing together the resources within the Nordic Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The inter-operation has two aspects, one is the data management part and the second the job management aspect. The first aspect was solved by using dCache across NDGF to handle data. Therefore, we will concentrate on the second part. Solving it, was somewhat cumbersome, mainly due to the different computing models employed by AliEn and ARC. AliEN uses an Agent based pull model while ARC handles jobs through the more 'traditional' push model. The solution comes as a module implementing the functionalities necessary to achieve AliEn job submission and management to ARC enabled sites

  16. Consolidating NASA's Arc Jets

    Science.gov (United States)

    Balboni, John A.; Gokcen, Tahir; Hui, Frank C. L.; Graube, Peter; Morrissey, Patricia; Lewis, Ronald

    2015-01-01

    The paper describes the consolidation of NASA's high powered arc-jet testing at a single location. The existing plasma arc-jet wind tunnels located at the Johnson Space Center were relocated to Ames Research Center while maintaining NASA's technical capability to ground-test thermal protection system materials under simulated atmospheric entry convective heating. The testing conditions at JSC were reproduced and successfully demonstrated at ARC through close collaboration between the two centers. New equipment was installed at Ames to provide test gases of pure nitrogen mixed with pure oxygen, and for future nitrogen-carbon dioxide mixtures. A new control system was custom designed, installed and tested. Tests demonstrated the capability of the 10 MW constricted-segmented arc heater at Ames meets the requirements of the major customer, NASA's Orion program. Solutions from an advanced computational fluid dynamics code were used to aid in characterizing the properties of the plasma stream and the surface environment on the calorimeters in the supersonic flow stream produced by the arc heater.

  17. The benefits and industrial experience from spectrometric borehole logging technology in the Pilbara iron ore deposits

    International Nuclear Information System (INIS)

    The CSIRO in Australia has carried out research and developed a family of borehole logging technologies known as SIROLOG which has applications to quantitative estimation in all phases of the iron ore mining industry, namely exploration, mine development and grade control in extraction. The techniques are spectrometric in relation to the detection and recording of the gamma rays which are either excited or scattered in within the ore matrix as a consequence of nuclear reactions. The spectrometric techniques developed by the CSIRO group included a gamma-gamma technique for the simultaneous determination of iron ore grade, bulk density and blast hole diameter and a neutron-gamma technique for the simultaneous determination of iron ore grade and silica contamination. In addition, the group developed both natural gamma and neutron activation techniques for determining alumina contamination. The paper discusses the instrumentation and equipment designed for manufacture by CSIRO, the methodology for calibration of probe responses against geological parameters and it presents a discussion of the results, particularly their precision and accuracy, which were obtained from routine logging operations in applications to production, exploration and mine development. (author). 10 refs., 9 figs., 2 tabs

  18. Micro-Plasma Transferred Arc Additive Manufacturing for Die and Mold Surface Remanufacturing

    Science.gov (United States)

    Jhavar, Suyog; Paul, Christ Prakash; Jain, Neelesh Kumar

    2016-05-01

    Micro-plasma transferred arc (µPTA) additive manufacturing is one of the newest options for remanufacturing of dies and molds surfaces in the near-millimeter range leading to extended usage of the same. We deployed an automatic micro-plasma deposition setup to deposit a wire of 300 µm of AISI P20 tool steel on the substrate of same material for the potential application in remanufacturing of the die and mold surface. Our present research effort is to establish µPTA additive manufacturing as a viable economical and cleaner methodology for potential industrial applications. We undertook the optimization of single weld bead geometry as the first step in our present study. Bead-on-plate trials were conducted to deposit single bead geometry at various processing parameters. The bead geometry (shape and size) and dilution were measured and the parametric dependence was derived. A set of parameters leading to reproducible regular and smooth single bead geometry were identified and used to prepare a thin wall for mechanical testing. The deposits were subjected to material characterization such as microscopic studies, micro-hardness measurements and tensile testing. The process was compared qualitatively with other deposition processes involving high-energy density beams and was found to be advantageous in terms of low initial and running costs with comparable properties. The outcome of the study confirmed the process capability of µPTA deposition leading to deployment of cost-effective and environmentally friendlier technology for die and mold remanufacturing.

  19. Micro-Plasma Transferred Arc Additive Manufacturing for Die and Mold Surface Remanufacturing

    Science.gov (United States)

    Jhavar, Suyog; Paul, Christ Prakash; Jain, Neelesh Kumar

    2016-07-01

    Micro-plasma transferred arc ( µPTA) additive manufacturing is one of the newest options for remanufacturing of dies and molds surfaces in the near-millimeter range leading to extended usage of the same. We deployed an automatic micro-plasma deposition setup to deposit a wire of 300 µm of AISI P20 tool steel on the substrate of same material for the potential application in remanufacturing of the die and mold surface. Our present research effort is to establish µPTA additive manufacturing as a viable economical and cleaner methodology for potential industrial applications. We undertook the optimization of single weld bead geometry as the first step in our present study. Bead-on-plate trials were conducted to deposit single bead geometry at various processing parameters. The bead geometry (shape and size) and dilution were measured and the parametric dependence was derived. A set of parameters leading to reproducible regular and smooth single bead geometry were identified and used to prepare a thin wall for mechanical testing. The deposits were subjected to material characterization such as microscopic studies, micro-hardness measurements and tensile testing. The process was compared qualitatively with other deposition processes involving high-energy density beams and was found to be advantageous in terms of low initial and running costs with comparable properties. The outcome of the study confirmed the process capability of µPTA deposition leading to deployment of cost-effective and environmentally friendlier technology for die and mold remanufacturing.

  20. Arc Plasma Torch Modeling

    CERN Document Server

    Trelles, J P; Vardelle, A; Heberlein, J V R

    2013-01-01

    Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This paper presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical non-equilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot-cathode and a nozzle anode.

  1. X-ray diffraction and SEM/EDX studies on technological evolution of the oxide-fluoride ceramic flux for submerged arc-surfacing

    Directory of Open Access Journals (Sweden)

    Sokolsky V.E.

    2012-01-01

    Full Text Available The ceramic flux for submerged arc-surfacing with main component composition MgO (10.0 wt. %-Al2O3 (25.0 wt. %-SiO2 (40.0 wt. %-CaF2 (25.0 wt. % was prepared in a disk dryer-granulator using a sodium/potassium silicate solution as a binder. X-ray powder diffraction (XRPD collected at r.t. identified α- phase of quartz, Al2O3, MgO and CaF2 of the initial components in the samples taken after granulation and subsequent annealing at 600 °C. In contrast to the low temperature annealing, anorthite (CaAl2Si2O8 is the main phase in the composition of the samples remelted at 1500 °C and quenched subsequently. Chemical analysis performed by means of scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis (SEM/EDX detects that the grains of the remelted samples possess the same Ca : Al : Si elemental ratio as anorthite. High temperature X-ray diffraction (HTXRD was used to examine structural transformation in the solid at 600 °C < T < 1200 °C and stages of thermal evolution of ceramic flux were determined. The ceramic flux melts completely at the temperature above 1350 °C. The intensity pattern of the flux melt was obtained by X-ray diffraction of scattered X-rays at 1450 °C. After calculating the structure factor (SF, the radial distribution function (RDF was evaluated and used to calculate the structural basicity of the flux melt.

  2. Cathodic arc grown niobium films for RF superconducting cavity applications

    Science.gov (United States)

    Catani, L.; Cianchi, A.; Lorkiewicz, J.; Tazzari, S.; Langner, J.; Strzyzewski, P.; Sadowski, M.; Andreone, A.; Cifariello, G.; Di Gennaro, E.; Lamura, G.; Russo, R.

    2006-07-01

    Experimental results on the characterization of the linear and non-linear microwave properties of niobium film produced by UHV cathodic arc deposition are presented. Surface impedance Zs as a function of RF field and intermodulation distortion (IMD) measurement have been carried out by using a dielectrically loaded resonant cavity operating at 7 GHz. The experimental data show that these samples have a lower level of intrinsic non-linearities at low temperature and low circulating power in comparison with Nb samples grown by sputtering. These results make UHV cathodic arc deposition a promising technique for the improvement of RF superconducting cavities for particle accelerators.

  3. Cathodic arc grown niobium films for RF superconducting cavity applications

    Energy Technology Data Exchange (ETDEWEB)

    Catani, L. [INFN-Roma2, Rome (Italy); Cianchi, A. [INFN-Roma2, Rome (Italy); Lorkiewicz, J. [INFN-Roma2, Rome (Italy); Tazzari, S. [Universita di Roma ' Tor Vergata' and INFN-Roma2, Rome (Italy); Langner, J. [Soltan Institute for Nuclear Studies, Swierk (Poland); Strzyzewski, P. [Soltan Institute for Nuclear Studies, Swierk (Poland); Sadowski, M. [Soltan Institute for Nuclear Studies, Swierk (Poland); Andreone, A. [University of Napoli ' Federico II' and INFN-NA, Naples (Italy); Cifariello, G. [University of Napoli ' Federico II' and INFN-NA, Naples (Italy); Di Gennaro, E. [University of Napoli ' Federico II' and INFN-NA, Naples (Italy); Lamura, G. [University of Napoli ' Federico II' and INFN-NA, Naples (Italy); Russo, R. [Seconda Universita di Napoli, INFN-NA, Naples (Italy)

    2006-07-15

    Experimental results on the characterization of the linear and non-linear microwave properties of niobium film produced by UHV cathodic arc deposition are presented. Surface impedance Z {sub s} as a function of RF field and intermodulation distortion (IMD) measurement have been carried out by using a dielectrically loaded resonant cavity operating at 7 GHz. The experimental data show that these samples have a lower level of intrinsic non-linearities at low temperature and low circulating power in comparison with Nb samples grown by sputtering. These results make UHV cathodic arc deposition a promising technique for the improvement of RF superconducting cavities for particle accelerators.

  4. Development of circuit model for arcing on solar panels

    International Nuclear Information System (INIS)

    The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 μs duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between insulator

  5. An influence of technological parameters of plasma-chemical deposition of SiO2 films on their electro-physical properties

    Science.gov (United States)

    Romanov, A. A.; Serkov, A. V.; Hruleva, E. S.

    2016-07-01

    In this article a formation process of dielectric films on silicon (100) and silicon carbide using plasma-chemical deposition is described. Experimental relationships of SiO2 films thickness and main technological parameters are presented. Values of electro-physical parameters of films are measured.

  6. ALICE: ARC integration

    CERN Document Server

    Anderlik, C; Kleist, J; Peters, A; Saiz, P

    2008-01-01

    AliEn or Alice Environment is the Grid middleware developed and used within the ALICE collaboration for storing and processing data in a distributed manner. ARC (Advanced Resource Connector) is the Grid middleware deployed across the Nordic countries and gluing together the resources within the Nordic Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The inter-operation has two aspects, one is the data management part and the second the job management aspect. The first aspect was solved by using dCache across NDGF to handle data. Therefore, we will concentrate on the second part. Solving it, was somewhat cumbersome, mainly due to the different computing models employed by AliEn and ARC. AliEN uses an Agent based pull model while ARC handles jobs through the more 'traditional' push model. The solution comes as a modu...

  7. Multi-layer Ti-based Coating Obtained by Arc PVD Method

    OpenAIRE

    Pavlov, Konstantin; Gorchakov, Konstantin; Gorchakova, Svetlana; Salojoki, Kari; Barchenko, Vladimir; Sokolov, Aleksandr

    2013-01-01

    We report the obtaining and primary studies of ~ 250microns thick multi-layer Ti-based protective coating deposited at high cooling rate from substance generated by cathode arc discharge in vacuum. High adhesion to steel substrate was attained through prior Arc plasma generator cleaning and successive Ion Bombardment method. All three arc-generated fractions including mainly droplet, vapour and ions have been utilised to form the coating. Obtained coating features pore-free, least defects and...

  8. Characterization of duplex stainless steel weld metals obtained by hybrid plasma-gas metal arc welding

    OpenAIRE

    Koray Yurtisik; Suha Tirkes; Igor Dykhno; C. Hakan Gur; Riza Gurbuz

    2013-01-01

    Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex mi...

  9. Atmospheric deposition of rare earth elements in Albania studied by the moss biomonitoring technique, neutron activation analysis and GIS technology.

    Science.gov (United States)

    Allajbeu, Sh; Yushin, N S; Qarri, F; Duliu, O G; Lazo, P; Frontasyeva, M V

    2016-07-01

    Rare earth elements (REEs) are typically conservative elements that are scarcely derived from anthropogenic sources. The mobilization of REEs in the environment requires the monitoring of these elements in environmental matrices, in which they are present at trace level. The determination of 11 REEs in carpet-forming moss species (Hypnum cupressiforme) collected from 44 sampling sites over the whole territory of the country were done by using epithermal neutron activation analysis (ENAA) at IBR-2 fast pulsed reactor in Dubna. This paper is focused on REEs (lanthanides) and Sc. Fe as typical consistent element and Th that appeared good correlations between the elements of lanthanides are included in this paper. Th, Sc, and REEs were never previously determined in the air deposition of Albania. Descriptive statistics were used for data treatment using MINITAB 17 software package. The median values of the elements under investigation were compared with those of the neighboring countries such as Bulgaria, Macedonia, Romania, and Serbia, as well as Norway which is selected as a clean area. Geographical distribution maps of the elements over the sampled territory were constructed using geographic information system (GIS) technology. Geochemical behavior of REEs in moss samples has been studied by using the ternary diagram of Sc-La-Th, Spider diagrams and multivariate analysis. It was revealed that the accumulation of REEs in current mosses is associated with the wind-blowing metal-enriched soils that is pointed out as the main emitting factor of the elements under investigation. PMID:27044293

  10. Processes of energy exchange between blasted electric arc and surrounding gas in arc heater channel

    Czech Academy of Sciences Publication Activity Database

    Heinz, J.; Šenk, J.; Hrabovský, Milan

    2002-01-01

    Roč. 52, supplement D (2002), s. 583. ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : electric arc , energy exchance, heater Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  11. TRIBOLOGICAL BEHAVIORS OF DUPLEX DLC/Al2O3 COATINGS FABRICATED USING MICRO-ARC OXIDATION AND FILTERED CATHODIC VACUUM ARC SYSTEM

    OpenAIRE

    Wu, X. L.; Li, X. J.; Zhang, X; W. B. XUE; G. A. CHENG; A. D. LIU

    2007-01-01

    Micro-arc oxidation technique (MAO) treatment produces a layer of alumina film on the surface of the aluminum alloy. A hard and uniform tetrahedral amorphous carbon film (diamond-like carbon, DLC) was deposited on the top of the alumina layer of the 2024 aluminum alloy by a pulsed filtered catholic vacuum arc (FCVA) deposition system with a metal vapor vacuum arc (MEVVA) source. The morphology and tribological properties of the duplex DLC/Al2O3 coating were investigated by a scanning electron...

  12. A study on consumable aided tungsten indirect arc welding

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Wang Yuxin; Feng Jicai

    2009-01-01

    A consumable aided tungsten indirect arc welding method has been studied. This method is different from the traditional TIG welding because it introduces an MIG welding torch into the traditional TIG welding system. An indirect arc is generated between the consumable electrode of the MIG welding torch and the tungsten electrode of the TIG welding torch, but not generated between the tungsten electrode of the welding torch and the base metal. Welding current flows from the consumable electrode to the tungsten electrode in the free-burning indirect arc. The consumable aided tungsten indirect arc welding not only rapidly melts the welding wire but also effectively restrains the excessive fusion of the base metal. The welding experiment and the theoretical analysis confirm that this method can obtain a high deposition rate and a low dilution ratio during the welding process.

  13. A review of vacuum ARC ion source research at ANSTO

    International Nuclear Information System (INIS)

    The authors talk briefly describes the history and current status of vacuum arc ion source research at the Australian Nuclear Science and Technology Organization (ANSTO). In addition, the author makes some mention of the important role of previous Vacuum Arc Ion Source Workshops in fostering the development of this research field internationally. During the period 1986 -89, a type of plasma centrifuge known as a vacuum arc centrifuge was developed at ANSTO as part of a research project on stable isotope separation. In this device, a high current vacuum arc discharge was used to produce a metal plasma which was subsequently rotated in an axial magnetic field. The high rotational speeds (105 - 106 rad sec-1) achievable with this method produce centrifugal separation of ions with different mass:charge ratios such as isotopic species. The first portent of things to come occurred in 1985 when Dr. Ian Brown visited ANSTO's Lucas Heights Research Laboratories and presented a talk on the metal vapour vacuum arc (MEVVA) ion source which had only recently been invented by Brown and co-workers, J. Galvin and R. MacGill, at Lawrence Berkeley Laboratory. For those of us involved in vacuum arc centrifuge research, this was an exciting development primarily because the metal vapour vacuum arc plasma source was common to both devices. Thus, a type of arc, which had since the 1930's been extensively investigated as a means of switching high current loads, had found wider application as a useful plasma source

  14. Deposition of nanoscale multilayer CrN/NbN physical vapor deposition coatings by high power impulse magnetron sputtering

    International Nuclear Information System (INIS)

    Nanoscale multilayer CrN/NbN physical vapor deposition (PVD) coatings are gaining reputation for their high corrosion and wear resistance. However, the CrN/NbN films deposited by ABS (arc bond sputtering) technology have some limitations such as macrodroplets, porosity, and less dense structures. The novel HIPIMS (high power impulse magnetron sputtering) technique produces macroparticle-free, highly ionized metal plasma, which brings advantages in both surface pretreatment and coating deposition stages of the PVD process. In this study, nanoscale multilayer CrN/NbN PVD coatings were pretreated and deposited with HIPIMS technology and compared with those deposited by HIPIMS-UBM (unbalanced magnetron) and by the ABS technique. In all cases Cr+ etching was utilized to enhance adhesion by low energy ion implantation. The coatings were deposited at 400 deg. C with substrate biased (Ub) at -75 V. During coating deposition, HIPIMS produced significantly high activation of nitrogen compared to the UBM as observed with mass spectroscopy. HIPIMS-deposited coatings revealed a bilayer period of 4.1 nm (total thickness: 2.9 μm) and hardness of 3025 HK0.025. TEM results revealed droplet free, denser microstructure with (200) preferred orientation for the HIPIMS coating owing to the increased ionization as compared to the more porous structure with random orientation observed in UBM coating. The dry sliding wear coefficient (Kc) of the coating was 1.8x10-15 m3 N-1 m-1, whereas the steady state coefficient of friction was 0.32. Potentiodynamic polarization tests revealed higher Ecorr values, higher pitting resistance (around potentials +400 to +600 mV), and lower corrosion current densities for HIPIMS deposited coatings as compared to the coatings deposited by ABS or HIPIMS-UBM. The corrosion behavior of the coatings qualitatively improved with the progressive use of HIPIMS from pretreatment stage to the coating deposition step

  15. Study on exploration theory and SAR technology for interlayer oxidation zone sandstone type uranium deposit and its application in Eastern Jungar Basin

    International Nuclear Information System (INIS)

    Started with analyzing the features of metallogenetic epoch and space distribution of typical interlayer oxidation zone sandstone type uranium deposit both in China and abroad and their relations of basin evolution, the authors have proposed the idea that the last unconformity mainly controls the metallogenetic epoch and the strength of structure activity after the last unconformity determines the deposit space. An exploration theory with the kernel from new events to the old one is put forward. The means and method to use SAR technology to identify ore-controlling key factors are discussed. An application study in Eastern Jungar Basin is performed

  16. Semicircular Rashba arc spin polarizer

    International Nuclear Information System (INIS)

    In this work, we study the generation of spin polarized currents using curved arcs of finite widths, in which the Rashba spin orbit interaction (RSOI) is present. Compared to the 1-dimensional RSOI arcs with zero widths studied previously, the finite width presents charge carriers with another degree of freedom along the transverse width of the arc, in addition to the longitudinal degree of freedom along the circumference of the arc. The asymmetry in the transverse direction due to the difference in the inner and outer radii of the arc breaks the antisymmetry of the longitudinal spin z current in a straight RSOI segment. This property can be exploited to generate spin z polarized current output from the RSOI arc by a spin unpolarized current input. The sign of the spin current can be manipulated by varying the arc dimensions

  17. Semicircular Rashba arc spin polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Bin Siu, Zhuo, E-mail: a0018876@nus.edu.sg [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 (Singapore); Advanced Concepts and Nanotechnology, Data Storage Institute, DSI Building, 5 Engineering Drive 1 (Off Kent Ridge Crescent, NUS), Singapore 117608 (Singapore); Jalil, Mansoor B. A. [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 (Singapore); Ghee Tan, Seng [Advanced Concepts and Nanotechnology, Data Storage Institute, DSI Building, 5 Engineering Drive 1 (Off Kent Ridge Crescent, NUS), Singapore 117608 (Singapore)

    2014-05-07

    In this work, we study the generation of spin polarized currents using curved arcs of finite widths, in which the Rashba spin orbit interaction (RSOI) is present. Compared to the 1-dimensional RSOI arcs with zero widths studied previously, the finite width presents charge carriers with another degree of freedom along the transverse width of the arc, in addition to the longitudinal degree of freedom along the circumference of the arc. The asymmetry in the transverse direction due to the difference in the inner and outer radii of the arc breaks the antisymmetry of the longitudinal spin z current in a straight RSOI segment. This property can be exploited to generate spin z polarized current output from the RSOI arc by a spin unpolarized current input. The sign of the spin current can be manipulated by varying the arc dimensions.

  18. Reabsorption of Radiation in Water-Vortex Stabilized Electric arc and Influence on arc Performance

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří

    Vol. 2. Brno: Department of Power Electrical and Electronic Engineering, Brno University of Technology, 2003 - (Gross, B.; Vávra, Z.; Bartl, J.), s. 312-315. (2). ISBN 80-214-2307-2. [Symposium on Physics of Switching arc/15th./. Nové Město na Moravě (CZ), 22.09.2003-26.09.2003] R&D Projects: GA ČR GA202/02/1027 Institutional research plan: CEZ:AV0Z2043910 Keywords : electric arc, reabsorption, radiation model Subject RIV: BL - Plasma and Gas Discharge Physics

  19. mARC: Memory by Association and Reinforcement of Contexts

    OpenAIRE

    Rimoux, Norbert; Descourt, Patrice

    2013-01-01

    This paper introduces the memory by Association and Reinforcement of Contexts (mARC). mARC is a novel data modeling technology rooted in the second quantization formulation of quantum mechanics. It is an all-purpose incremental and unsupervised data storage and retrieval system which can be applied to all types of signal or data, structured or unstructured, textual or not. mARC can be applied to a wide range of information clas-sification and retrieval problems like e-Discovery or contextual ...

  20. Volcano collapse along the Aleutian Ridge (western Aleutian Arc)

    OpenAIRE

    Montanaro, C.; J. Beget

    2011-01-01

    The Aleutian Ridge, in the western part of the Aleutian Arc, consists of a chain of volcanic islands perched atop the crest of a submarine ridge with most of the active Quaternary stratocones or caldera-like volcanoes being located on the northern margins of the Aleutian Islands. Integrated analysis of marine and terrestrial data resulted in the identification and characterization of 17 extensive submarine debris avalanche deposits from 11 volcanoes. Two morphological types of deposits are re...

  1. Arc cathode spots

    International Nuclear Information System (INIS)

    Arc spots are usually highly unstable and jump statistically over the cathode surface. In a magnetic field parallel to the surface, preferably they move in the retrograde direction; i.e., opposite to the Lorentzian rule. If the field is inclined with respect to the surface, the spots drift away at a certain angle with respect to the proper retrograde direction (Robson drift motion). These well-known phenomena are explained by one stability theory

  2. Vacuum Arc Ion Sources

    OpenAIRE

    Brown, I.

    2014-01-01

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the sourc...

  3. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

    The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

  4. Clinical Applications of Volumetric Modulated Arc Therapy

    International Nuclear Information System (INIS)

    Purpose: To present treatment planning case studies for several treatment sites for which volumetric modulated arc therapy (VMAT) could have a positive impact; and to share an initial clinical experience with VMAT for stereotactic body radiotherapy (SBRT). Methods and Materials: Four case studies are presented to show the potential benefit of VMAT compared with conformal and intensity-modulated radiotherapy (IMRT) techniques in pediatric cancer, bone marrow-sparing whole-abdominopelvic irradiation (WAPI), and SBRT of the lung and spine. Details of clinical implementation of VMAT for SBRT are presented. The VMAT plans are compared with conventional techniques in terms of dosimetric quality and delivery efficiency. Results: Volumetric modulated arc therapy reduced the treatment time of spine SBRT by 37% and improved isodose conformality. Conformal and VMAT techniques for lung SBRT had similar dosimetric quality, but VMAT had improved target coverage and took 59% less time to deliver, although monitor units were increased by 5%. In a complex pediatric pelvic example, VMAT reduced treatment time by 78% and monitor units by 25% compared with IMRT. A double-isocenter VMAT technique for WAPI can spare bone marrow while maintaining good delivery efficiency. Conclusions: Volumetric modulated arc therapy is a new technology that may benefit different patient populations, including pediatric cancer patients and those undergoing concurrent chemotherapy and WAPI. Volumetric modulated arc therapy has been used and shown to be beneficial for significantly improving delivery efficiency of lung and spine SBRT.

  5. Arc-preserving subsequences of arc-annotated sequences

    CERN Document Server

    Popov, Vladimir Yu

    2011-01-01

    Arc-annotated sequences are useful in representing the structural information of RNA and protein sequences. The longest arc-preserving common subsequence problem has been introduced as a framework for studying the similarity of arc-annotated sequences. In this paper, we consider arc-annotated sequences with various arc structures. We consider the longest arc preserving common subsequence problem. In particular, we show that the decision version of the 1-{\\sc fragment LAPCS(crossing,chain)} and the decision version of the 0-{\\sc diagonal LAPCS(crossing,chain)} are {\\bf NP}-complete for some fixed alphabet $\\Sigma$ such that $|\\Sigma| = 2$. Also we show that if $|\\Sigma| = 1$, then the decision version of the 1-{\\sc fragment LAPCS(unlimited, plain)} and the decision version of the 0-{\\sc diagonal LAPCS(unlimited, plain)} are {\\bf NP}-complete.

  6. Volcanic evolution of the South Sandwich volcanic arc, South Atlantic, from multibeam bathymetry

    OpenAIRE

    Leat, Philip T; Day, Simon J; Tate, Alex J.; Martin, Tara J; Owen, Matthew J; Tappin, David R.

    2013-01-01

    New multibeam bathymetry data are presented for the South Sandwich intra-oceanic arc which occupies the small Sandwich plate in the South Atlantic, and is widely considered to be a simple end-member in the range of intra-oceanic arc types. The images show for the first time the distribution of submarine volcanic, tectonic and erosional-depositional features along the whole length of the 540 km long volcanic arc, allowing systematic investigation of along-arc variations. The data confirm that ...

  7. Investigation of Electrode Erosion Mechanism of Multi-Phase AC Arc by High-Speed Video Camera

    International Nuclear Information System (INIS)

    A multi-phase AC arc has been applied to the glass melting technology. However, the electrode erosion is one of the most considerable issues to be solved. In order to investigate the erosion mechanism of the multi-phase AC arc, the combination of the high-speed video camera and the band-pass filters was introduced to measure the electrode temperature. Results indicated the tip temperature of the electrode surface in the 12-phase arc was lower than that in the 2-phase arc, while erosion rate in 12-phase arc was higher than that in the 2-phase arc. Furthermore, the dynamic behaviour of the vapours in the arc was investigated by using the same high-speed camera system. The tungsten electrode mainly evaporates at the anodic period during AC cycle. The oxygen concentration in the arc increases with larger number of the phases, resulting in the higher erosion rate in the 12-phase arc.

  8. Applications of ZnO:Al deposited by RF sputtering to InN low-cost technology

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S. [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Naranjo, F.B.; Valdueza-Felip, S. [Grupo de Ingenieria Fotonica, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala Campus Universitario, Madrid (Spain); Abril, O. de [ISOM y Departamento de Fisica Aplicada, Escuela Tecnica Superior de Ingenieros de Telecomunicacion, Universidad Politenica de Madrid (Spain)

    2010-07-15

    InN/ZnO:Al heterostructures deposited at low temperature on different substrates by radio-frequency sputtering were studied. Using ZnO:Al as buffer layer, an improvement in the InN structural properties was achieved. Evaluating ZnO:Al as contact on InN, an Ohmic behaviour for the as-deposited layer on InN was achieved. A specific contact resistance of 2 {omega} cm{sup 2} was measured without any post-deposition treatment. These properties could result very promising for optoelectronic device applications. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  9. Gas tungsten arc welder

    International Nuclear Information System (INIS)

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable grinder, co-axial with the electrode, is provided in the enclosure for refurbishing the used electrode between welds. The specification also discloses means for loading of the cladding with fuel pellets and for placement of reflectors, gas capsules and end caps. Gravity feed conveyor and inerting means are also described. (author)

  10. Development of integrated evaluation information system for sandstone-hosted uranium deposits based on ComGIS

    International Nuclear Information System (INIS)

    Component GIS owns many merits such as flexible function and easy to be used, which makes it very suitable for the development of professional GIS application system in geoscience field. During the process of exploration and evaluation for uranium resources, computer application system has been a powerful tool owning to the following functions: professional processing, management and storage of data, spatial analysis, visualization and mapping, etc. In this paper technological routine is presented for the development of integrated evaluation information system for sandstone-hosted uranium deposits based on ArcGIS Engine. General GIS functions can be realized with ArcGIS Engine easily and quickly, the developers could concentrate their attentions on developing professional functions, which will shorten the developing period and make the system more efficient. It is showed that the system developed on ArcGIS Engine platform is stable in operation, flexible in functions and professional in application. (authors)

  11. APPLICATION OF REVERSE OSMOSIS TECHNOLOGY TO THE DESALINATION PROCESS IN SUPPLEMENT WATER FOR SUBMERGED ARC FURNACE%反渗透技术在矿热炉补充水除盐工艺的应用

    Institute of Scientific and Technical Information of China (English)

    吴秋勤; 曾世林; 王正

    2015-01-01

    This paper introduced the application of reverse osmosis technology to the desalination process in supplement water for submerged arc furnace. It tested the effects of original water suspended matter concentration,hardness and static pressure difference both sides of RO membrane on system operation, water yield and desalination rate. The result shows that original water suspended matter has great effects on system water production and original water hardness has less ef-fect on RO water production. It is beneficial to enhance desalination to decrease the static pressure difference both sides of RO membrane. It plays a key role in normal operation of system to increase combined deep pretreatment, decrease the original water concentration and strengthen germicide and algicide in pretreatment stage.%介绍了反渗透技术在矿热炉补充水除盐工艺中的应用,并进行了原水悬浮物浓度、硬度和RO膜两侧静压差对系统运行状况、产水量和除盐率影响的测试.结果表明,原水悬浮物对系统产水量有严重影响;原水硬度对RO产水量影响相对较小;RO膜两侧静差降低,有利于提高除盐率.增加组合深度预处理工序,降低原水的悬浮物浓度,强化预处理阶段杀菌灭藻,对除盐系统设备正常运行起关键作用.

  12. Electric arc welding gun

    Science.gov (United States)

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  13. Fatigue life prediction of crankshaft repaired by twin arc spraying

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-qing; WANG Cheng-tao; PU Geng-qiang

    2005-01-01

    This paper used Baumel Jr. and Seeger's approach estimating fatigue parameters of 48MnV with 3Cr13coatings. The fatigue life of the crankshaft of a six-cylinder engine, repaired by twin arc spraying 3cr13 deposits, is respectively calculated using different damage model such as S-N method, normal strain approaches, SWT-Bannantine approaches, shear strain approaches, and fatemi-Socie method based on dynamical simulation and FE analysis of crankshaft. The results indicate that the traditional calculation is conservative and that the life of crankshaft repaired by arc spraying is sufficient.

  14. Destruction of PCDD/Fs by gliding arc discharges

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PCDD/Fs have been become a serious issue because of their lexicological effects and associated adverse health implications. In this study, the gliding arc plasma was tested for treatment of polychlorinated dibenzo-p-dioxins (PCDDs) and pol ychlorinated dibenzofurans (PCDFs), which was synthesized from pentachlorophenol in atmospheric condition at 350℃ with or without the catalysis of CuCh-From the experiment, we found that the destruction efficiency of PCDD/F homologues after gliding was discharge ranged from 25% to 79%. This result demonstrates that gliding arc plasma is an effective technology to decompose PCDDs/Fs in flue gas. A plausible degradation mechanism for PCDD/Fs by gliding arc was discussed. Finally, a multistage reactor structure of gliding arc was proposed to upgrade removal efficiency for PCDD/Fs.

  15. Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

    Institute of Scientific and Technical Information of China (English)

    Xiong Yu-Qing; Li Xing-Cun; Chen Qiang; Lei Wen-Wen; Zhao Qiao; Sang Li-Jun; Liu Zhong-Wei; Wang Zheng-Duo; Yang Li-Zhen

    2012-01-01

    Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas.We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity.The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal.Through chemical and structural analysis,we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology,but by both the crystallinity and crystal size in this process.

  16. Evolution of Ore Deposits and Technology Transfer Project: Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008

    Science.gov (United States)

    Rye, Robert O.; Johnson, Craig A.; Landis, Gary P.; Hofstra, Albert H.; Emsbo, Poul; Stricker, Craig A.; Hunt, Andrew G.; Rusk, Brian G.

    2010-01-01

    Principal functions of the U.S. Geological Survey (USGS) Mineral Resources Program are providing assessments of the location, quantity, and quality of undiscovered mineral deposits, and predicting the environmental impacts of exploration and mine development. The mineral and environmental assessments of domestic deposits are used by planners and decisionmakers to improve the stewardship of public lands and public resources. Assessments of undiscovered mineral deposits on a global scale reveal the potential availability of minerals to the United States and other countries that manufacture goods imported to the United States. These resources are of fundamental relevance to national and international economic and security policy in our globalized world economy. Performing mineral and environmental assessments requires that predictions be made of the likelihood of undiscovered deposits. The predictions are based on geologic and geoenvironmental models that are constructed for the diverse types of mineral deposits from detailed descriptions of actual deposits and detailed understanding of the processes that formed them. Over the past three decades the understanding of ore-forming processes has benefited greatly from the integration of laboratory-based geochemical tools with field observations and other data sources. Under the aegis of the Evolution of Ore Deposits and Technology Transfer Project (referred to hereinafter as the Project), a 5-year effort that terminated in 2008, the Mineral Resources Program provided state-of-the-art analytical capabilities to support applications of several related geochemical tools to ore-deposit-related studies. The analytical capabilities and scientific approaches developed within the Project have wide applicability within Earth-system science. For this reason the Project Laboratories represent a valuable catalyst for interdisciplinary collaborations of the type that should be formed in the coming years for the United States to meet

  17. Contrasting sedimentary processes along a convergent margin: the Lesser Antilles arc system

    Science.gov (United States)

    Picard, Michel; Schneider, Jean-Luc; Boudon, Georges

    2006-12-01

    Sedimentation processes occurring in an active convergent setting are well illustrated in the Lesser Antilles island arc. The margin is related to westward subduction of the North and/or the South America plates beneath the Caribbean plate. From east to west, the arc can be subdivided into several tectono-sedimentary depositional domains: the accretionary prism, the fore-arc basin, the arc platform and inter-arc basin, and the Grenada back-arc basin. The Grenada back-arc basin, the fore-arc basin (Tobago Trough) and the accretionary prism on the east side of the volcanic arc constitute traps for particles derived from the arc platform and the South American continent. The arc is volcanically active, and provides large volumes of volcaniclastic sediments which accumulate mainly in the Grenada basin by volcaniclastic gravity flows (volcanic debris avalanches, debris flows, turbiditic flows) and minor amounts by fallout. By contrast, the eastern side of the margin is fed by ash fallout and minor volcaniclastic turbidites. In this area, the dominant component of the sediments is pelagic in origin, or derived from South America (siliciclastic turbidites). Insular shelves are the locations of carbonate sedimentation, such as large platforms which develop in the Limestone Caribbees in the northern part of the margin. Reworking of carbonate material by turbidity currents also delivers lesser amounts to eastern basins of the margin. This contrasting sedimentation on both sides of the arc platform along the margin is controlled by several interacting factors including basin morphology, volcanic productivity, wind and deep-sea current patterns, and sea-level changes. Basin morphology appears to be the most dominant factor. The western slopes of the arc platform are steeper than the eastern ones, thus favouring gravity flow processes.

  18. Of Eggs and Arcs

    Science.gov (United States)

    Burns, Joseph A.; Thomas, P. C.; Helfenstein, P.; Tiscareno, M. S.; Hedman, M. M.; Agarwal, M.

    2012-10-01

    New scenarios for the origins of Saturn’s rings/interior moons have directed scientific attention to the region just exterior to Saturn’s main rings. Four satellites (Aegaeon = Ae; Anthe = An; Methone = Me; Pallene = Pa) discovered by the Cassini mission on either side of Mimas’s orbit perhaps comprise a distinct class of ring-moon. They are tiny (R = 0.3-2.5 km); three (AeAnMe) are trapped in co-rotation resonances with Mimas and reside within ring-arcs; and at least two (MePa) have remarkably regular shapes. Images with pixel scales as fine as 27 m taken in May 2012 reveal Methone to be ovoid within 10 m (from sub-pixel limb detection) and devoid of any craters (>130 m) across its 9 km2 of surface; Pallene and even tiny Aegaeon have similar appearances in lesser-quality images. Numerical simulations demonstrate that particles comprising the surrounding ring-arcs populate the same resonances as their embedded moons; escape speeds from the moons are bodies. In this environment, the moons’ shapes are smooth equipotentials; electrostatic effects may also determine how grains settle to surfaces. Considering these shapes to represent equipotential surfaces for rotating, tidally distorted, homogeneous bodies, we infer mean satellite densities of 250+/-60 (Pa), 310+/-30 (Me), and 540+/-120 (Ae) kg m-3. About half of Methone’s leading hemisphere is covered by a sharply bounded, lemon-shaped, relatively dark region, having a form reminiscent of Mimas’s thermal anomaly (Howett et al. 2011). Its (601 nm) albedo is 13% lower than the bounding brighter material. An irregularly shaped, even-darker (by 4%) blotch straddles the apex of the moon’s motion. Impacts with circum-planetary meteoroids and plasma are likely responsible for these features.

  19. Purging means and method for Xenon arc lamps

    Science.gov (United States)

    Miller, C. G. (Inventor)

    1973-01-01

    High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.

  20. Characterization of degradation fragments released by arc-induced ablation of polymers in air

    International Nuclear Information System (INIS)

    Polymers exposed to high intensity arc plasmas release material in a process called arc-induced ablation. In order to investigate the degradation fragments released due to this process, two different polymeric materials, poly(oxymethylene) copolymer (POM-C) and poly(methyl methacrylate) (PMMA), were exposed to a transient, high-power arc plasma in air. A small fraction of the ablated material drifting away from the arcing volume was deposited on a fixed glass substrate during the total duration of a 2 kA ac current semicycle. In addition, another fraction of the released material was deposited on a second moving substrate to obtain a time-resolved streak ‘image’ of the arc-induced ablation process. For the first time, mass spectra of degradation fragments produced by arc-induced ablation were obtained from the material deposited on the substrates by using laser desorption ionization time-of-flight mass spectrometry (LDI-ToF-MS). It was found that oligomers with mean molecular weight ranging between 400 and 600 Da were released from the surface of the studied polymers. The obtained spectra suggest that the detected degradation fragments of POM could be released by random chain scission of the polymer backbone. In turn, random chain scission and splitting-off the side groups are suggested as the main chemical mechanism leading to the release of PMMA fragments under arc-induced ablation. (paper)

  1. Arc Interference Behavior during Twin Wire Gas Metal Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Dingjian Ye

    2013-01-01

    Full Text Available In order to study arc interference behavior during twin wire gas metal arc welding process, the synchronous acquisition system has been established to acquire instantaneous information of arc profile including dynamic arc length variation as well as relative voltage and current signals. The results show that after trailing arc (T-arc is added to the middle arc (M-arc in a stable welding process, the current of M arc remains unchanged while the agitation increases; the voltage of M arc has an obvious increase; the shape of M arc changes, with increasing width, length, and area; the transfer frequency of M arc droplet increases and the droplet itself becomes smaller. The wire extension length of twin arc turns out to be shorter than that of single arc welding.

  2. Scale-up approach for industrial plasma enhanced chemical vapor deposition processes and SiOx thin film technology

    International Nuclear Information System (INIS)

    A high efficiency, large area deposition process was developed for silicon oxide films using a scale-up of plasma-enhanced chemical vapor deposition (PECVD) with an additional modified electrode design. We constructed an advanced plasma source by modifying an 8 in. electrode used in small-scale PECVD into a 370 × 470 mm electrode for large area PECVD. The effect of the modified electrode design on the large area and the mechanical properties of the silicon oxide films produced from the setup were examined. Dissociation of octamethylycyclodisiloxane (OMCTS) precursor was controlled by the plasma processing parameters. SiOx films were deposited on polycarbonate substrates by PECVD using OMCTS and oxygen carrier gas. The uniformity of the SiOx film and the mechanical properties were improved by the modified PECVD system design. The plasma was analyzed by optical emission spectroscopy. In addition, we measured the neutral radicals in the plasma by a residual gas analyzer. The mechanical properties of the coatings were examined using a nano-indenter and pencil hardness measurements. The chemical properties of the coatings were examined by Fourier transform infrared spectroscopy. The uniformity and film properties of the SiOx films were controlled by the dissociation of OMCTS using the appropriate intensity of excited neutrals, ionized atoms and input power with RF bias. - Highlights: • SiOx thin films synthesized using scale-up PECVD. • Large area deposition process was developed by modified electrode. • Plasma process enables high mechanical properties (Hardness 8H and 6.93 GPa)

  3. High current electric arcs; Les arcs electriques a fort courant

    Energy Technology Data Exchange (ETDEWEB)

    Delalondre, C.; Simonin, O. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique; Mineau, L. [Electricite de France (EDF), 75 - Paris (France). Dept. Systemes Energetiques; Verite, J.C. [Electricite de France (EDF), 75 - Paris (France). Dept. Cables, Condensateurs, Materiel d' Automatisme et Materiaux

    1999-07-01

    The mechanisms called into play through the interaction between a high current electric arc and the surrounding environment have an essential role to play in the performance of arc furnaces and high voltage circuit breakers. Our knowledge of them remains poor, and because of the very high temperatures and speeds involved, experimental investigation is particularly difficult. What can numerical modelling teach us about these phenomena? (authors)

  4. Antireflection coatings on plastics deposited by plasma polymerization process

    Indian Academy of Sciences (India)

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

    2008-08-01

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

  5. A review of vacuum ARC ion source research at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Evans, P.J.; Noorman, J.T.; Watt, G.C. [ANSTO, Menai (Australia)

    1996-08-01

    The authors talk briefly describes the history and current status of vacuum arc ion source research at the Australian Nuclear Science and Technology Organization (ANSTO). In addition, the author makes some mention of the important role of previous Vacuum Arc Ion Source Workshops in fostering the development of this research field internationally. During the period 1986 - 89, a type of plasma centrifuge known as a vacuum arc centrifuge was developed at ANSTO as part of a research project on stable isotope separation. In this device, a high current vacuum arc discharge was used to produce a metal plasma which was subsequently rotated in an axial magnetic field. The high rotational speeds (10{sup 5} - 10{sup 6} rad sec{sup {minus}1}) achievable with this method produce centrifugal separation of ions with different mass:charge ratios such as isotopic species. The first portent of things to come occurred in 1985 when Dr. Ian Brown visited ANSTO`s Lucas Heights Research Laboratories and presented a talk on the metal vapour vacuum arc (MEVVA) ion source which had only recently been invented by Brown and co-workers, J. Galvin and R. MacGill, at Lawrence Berkeley Laboratory. For those of us involved in vacuum arc centrifuge research, this was an exciting development primarily because the metal vapour vacuum arc plasma source was common to both devices. Thus, a type of arc, which had since the 1930`s been extensively investigated as a means of switching high current loads, had found wider application as a useful plasma source.

  6. A novel corrosion and abrasion resistant internal coating method with improved adhesion using hollow cathode PECVD (Plasma Enhanced Chemical Vapor Deposition) technology

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, B.; Boinapally, K.; Casserly, T.; Upadhyaya, D.; Gupta, M.; Dornfest, C. [SubOne Technology, Pleasanton, CA (United States)

    2008-07-01

    A new enabling technology for coating the internal surfaces of pipes with a hard, corrosion, wear resistant diamond-like-carbon (DLC) coating is described. The importance of proper surface preparation and optimized interface and adhesion layer is shown. Corrosion resistance is measured based on exposure to HCl, NaCl environments and autoclave with H{sub 2}S. Mechanical properties include high hardness, high adhesion, and excellent wear resistance including sand abrasion resistance. The coating is optimized for high hardness and deposition rate based on selection on the proper hydrocarbon precursor. This new technology enables wide spread use of DLC based coating to increase component life in applications where internal surface of pipes are exposed to corrosive and abrasive environment especially in the oil and gas industry. (author)

  7. STUDY ON THE PRESSURE IN PLASMA ARC

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The axial pressure in plasma arc is measured under different conditions. The effects of the parameters, such as welding current, plasma gas flow rate, electrode setback and arc length, on the pressure in plasma arc are investigated and quantitative analyzed to explain the relationship between the quality of weld and the matching of parameters in plasma arc welding process.

  8. Arcing and its role in PFC erosion and dust production in DIII-D

    Science.gov (United States)

    Rudakov, D. L.; Chrobak, C. P.; Doerner, R. P.; Krasheninnikov, S. I.; Moyer, R. A.; Umstadter, K. R.; Wampler, W. R.; Wong, C. P. C.

    2013-07-01

    Two types of arc tracks are observed on the plasma-facing components (PFCs) in DIII-D. "Unmagnetized" random walk tracks are produced during glow discharges; they are rare and have no importance for PFC erosion but may degrade diagnostic mirrors. "Magnetized" scratch-like type II tracks are produced by unipolar arcs during plasma operations; they are formed by "retrograde BxJ" motion of the cathode spot and are roughly perpendicular to the local magnetic field. Type II arcs cause measurable erosion of graphite, but based on the evidence available they are relatively small contributors to the total erosion of carbon in DIII-D compared to other mechanisms such as physical and chemical sputtering and ablation from leading edges. Erosion by arcing of tungsten films deposited on graphite samples was observed in Divertor Material Evaluation System (DiMES) experiments. New DiMES experiments aimed at time-resolved arc measurements are proposed.

  9. Continental arc volcanism as the principal driver of icehouse-greenhouse variability.

    Science.gov (United States)

    McKenzie, N Ryan; Horton, Brian K; Loomis, Shannon E; Stockli, Daniel F; Planavsky, Noah J; Lee, Cin-Ty A

    2016-04-22

    Variations in continental volcanic arc emissions have the potential to control atmospheric carbon dioxide (CO2) levels and climate change on multimillion-year time scales. Here we present a compilation of ~120,000 detrital zircon uranium-lead (U-Pb) ages from global sedimentary deposits as a proxy to track the spatial distribution of continental magmatic arc systems from the Cryogenian period to the present. These data demonstrate a direct relationship between global arc activity and major climate shifts: Widespread continental arcs correspond with prominent early Paleozoic and Mesozoic greenhouse climates, whereas reduced continental arc activity corresponds with icehouse climates of the Cryogenian, Late Ordovician, late Paleozoic, and Cenozoic. This persistent coupled behavior provides evidence that continental volcanic outgassing drove long-term shifts in atmospheric CO2 levels over the past ~720 million years. PMID:27102480

  10. Surface Catalysis and Oxidation on Stagnation Point Heat Flux Measurements in High Enthalpy Arc Jets

    Science.gov (United States)

    Nawaz, Anuscheh; Driver, David M.; Terrazas-Salinas

    2013-01-01

    Heat flux sensors are routinely used in arc jet facilities to determine heat transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these heat flux sensors. Surface compositions can change due to oxidation and material deposition from the arc jet. Systematic surface analyses of the sensors were conducted before and after exposure to plasma. Currently copper is commonly used as surface material. Other surface materials were studied including nickel, constantan gold, platinum and silicon dioxide. The surfaces were exposed to plasma between 0.3 seconds and 3 seconds. Surface changes due to oxidation as well as copper deposition from the arc jets were observed. Results from changes in measured heat flux as a function of surface catalycity is given, along with a first assessment of enthalpy for these measurements. The use of cupric oxide is recommended for future heat flux measurements, due to its consistent surface composition arc jets.

  11. Remote Sensing Technology for Identification of Alteration Information of Gold Deposits in the Eastern Tianshan Area, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    FU Shuixing; ZHANG Shoulin; LI Chunxia; FENG Jianzhong; FANG Tonghui; SUN Baosheng

    2004-01-01

    Based on specific well-exposed rocks useful for high-quality remote sensing interpretation in the goldprospecting area in the eastern Tianshan, this paper gives a detailed description of a remote sensing model for metallogenic prediction. The model reveals that multi-spectral remote sensing data are integrated with high-resolution remote sensing data, and enhanced extraction and visual description of weak remote sensing information are used for prospecting. This model has tested in the given gold deposit, and used successfully in Au-Cu prospecting in the Kalatage area.

  12. A review-application of physical vapor deposition (PVD) and related methods in the textile industry

    Science.gov (United States)

    Shahidi, Sheila; Moazzenchi, Bahareh; Ghoranneviss, Mahmood

    2015-09-01

    Physical vapor deposition (PVD) is a coating process in which thin films are deposited by the condensation of a vaporized form of the desired film material onto the substrate. The PVD process is carried out in a vacuum. PVD processes include different types, such as: cathode arc deposition, electron beam physical vapor deposition, evaporative deposition, sputtering, ion plating and enhanced sputtering. In the PVD method, the solid coating material is evaporated by heat or by bombardment with ions (sputtering). At the same time, a reactive gas is also introduced; it forms a compound with the metal vapor and is deposited on the substrate as a thin film with highly adherent coating. Such coatings are used in a wide range of applications such as aerospace, automotive, surgical, medical, dyes and molds for all manner of material processing, cutting tools, firearms, optics, thin films and textiles. The objective of this work is to give a comprehensive description and review of the science and technology related to physical vapor deposition with particular emphasis on their potential use in the textile industry. Physical vapor deposition has opened up new possibilities in the modification of textile materials and is an exciting prospect for usage in textile design and technical textiles. The basic principle of PVD is explained and the major applications, particularly sputter coatings in the modification and functionalization of textiles, are introduced in this research.

  13. Alleviation of process-induced cracking of the antireflection TiN coating (ARC-TiN) in Al-Cu and Al-Cu-Si films

    CERN Document Server

    Peng, Y C; Yang, Y R; Hsieh, W Y; Hsieh, Y F

    1999-01-01

    The alleviation of cracking of the TiN-ARC layer on Al-Cu and Al-Cu-Si films after the development process has been achieved. For the TiN-ARC/Al-Cu system, the stress-induced defects decreased with increasing TiN-ARC layer thickness. In contrast, for the TiN-ARC/Al-Cu-Si system, Si nodules formed during cooling, thereby inducing poor coverage with high aspect-ratio holes. As a result, the photoresist developer penetrated through the films. Chemical vapor deposition of TiN-ARC or predeposition of a Ti Interposing layer was used to eliminate the formation of Si nodules.

  14. Alleviation of process-induced cracking of the antireflection TiN coating (ARC-TiN) in Al-Cu and Al-Cu-Si films

    International Nuclear Information System (INIS)

    The alleviation of cracking of the TiN-ARC layer on Al-Cu and Al-Cu-Si films after the development process has been achieved. For the TiN-ARC/Al-Cu system, the stress-induced defects decreased with increasing TiN-ARC layer thickness. In contrast, for the TiN-ARC/Al-Cu-Si system, Si nodules formed during cooling, thereby inducing poor coverage with high aspect-ratio holes. As a result, the photoresist developer penetrated through the films. Chemical vapor deposition of TiN-ARC or predeposition of a Ti Interposing layer was used to eliminate the formation of Si nodules

  15. Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge

    International Nuclear Information System (INIS)

    Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents equal 20...30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities of the cathode vacuum arc discharge

  16. Implementation method of Oil and Gas Geologic Information System with ArcGIS Engine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    ComGIS is the mainstream of developing GIS currently. Developing Geographic Information System with the technology of components can reduce the difficulties of developing, improving the developing efficiency and enhancing the flexibility and opening of system. AxcObjects(AO) is based on the technology of COM, and ArcGIS Engine(AE) is a set of embedded AO which can extend to various platforms. Compared with AO, ArcGIS Engine can shorten the period of developing and improve the efficiency greatly. Having introduced the techniques of ArcObjects and ArcGIS Engine, we offer the method of developing GIS with Visual Basic and ArcGIS Engine with Oil and Gas Geologic Information System.

  17. Microstrain and residual stress in thin-films made from silver nanoparticles deposited by inkjet-printing technology

    NARCIS (Netherlands)

    Cauchois, R.; Borbély, A.; Gergaud, P.; Saadaoui, M.; Inal, K.

    2014-01-01

    Colloidal suspensions of nanoparticles are increasingly employed in the fabrication process of electronic devices using inkjet-printing technology and a consecutive thermal treatment. The evolution of internal stresses during the conversion of silver nanoparticle-based ink into a metallic thin-film

  18. Do technological advances in linear accelerators improve dosimetric outcomes in stereotaxy? A head-on comparison of seven linear accelerators using volumetric modulated arc therapy-based stereotactic planning

    OpenAIRE

    Sarkar, B.; Pradhan, A.; A Munshi

    2016-01-01

    Introduction: Linear accelerator (Linac) based stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) using volumetric modulated arc therapy (VMAT) has been used for treating small intracranial lesions. Recent development in the Linacs such as inbuilt micro multileaf collimator (MLC) and flattening filter free (FFF) beam are intended to provide a better dose conformity and faster delivery when using VMAT technique. This study was aimed to compare the dosimetric outcomes and monit...

  19. Dosimetric and delivery characterizations of full-arc and half-arc volumetric-modulated arc therapy for maxillary cancer

    International Nuclear Information System (INIS)

    We compared the efficiency and accuracy of full-arc and half-arc volumetric-modulated arc therapy (VMAT) delivery for maxillary cancer. Plans for gantry rotation angles of 360deg and 180deg (full-arc and half-arc VMAT) were created for six maxillary cancer cases with the Monaco treatment planning system, and delivered using an Elekta Synergy linear accelerator. Full-arc and half-arc VMAT were compared with regard to homogeneity index (HI), conformity index (CI), mean dose to normal brain, total monitor units (MU), delivery times, root mean square (r.m.s.) gantry accelerations (deg/s2), and r.m.s. gantry angle errors (deg). The half-arc VMAT plans achieved comparable HI and CI to the full-arc plans. Mean doses to the normal brain and brainstem with the half-arc VMAT plans were on average 16% and 17% lower than those with the full-arc VMAT plans. For other organs at risk (OARs), no significant dose volume histogram (DVH) differences were observed between plans. Half-arc VMAT resulted in 11% less total MU and 20% shorter delivery time than the full-arc VMAT, while r.m.s. gantry acceleration and r.m.s. gantry angle error during half-arc VMAT delivery were 30% and 23% less than those during full-arc VMAT delivery, respectively. Furthermore, the half-arc VMAT plans were comparable with the full-arc plans regarding dose homogeneity and conformity in maxillary cancer, and provided a statistical decrease in mean dose to OAR, total MU, delivery time and gantry angle error. Half-arc VMAT plans may be a suitable treatment option in radiotherapy for maxillary cancer. (author)

  20. Massive edifice failure at Aleutian arc volcanoes

    Science.gov (United States)

    Coombs, M.L.; White, S.M.; Scholl, D. W.

    2007-01-01

    Along the 450-km-long stretch of the Aleutian volcanic arc from Great Sitkin to Kiska Islands, edifice failure and submarine debris-avalanche deposition have occurred at seven of ten Quaternary volcanic centers. Reconnaissance geologic studies have identified subaerial evidence for large-scale prehistoric collapse events at five of the centers (Great Sitkin, Kanaga, Tanaga, Gareloi, and Segula). Side-scan sonar data collected in the 1980s by GLORIA surveys reveal a hummocky seafloor fabric north of several islands, notably Great Sitkin, Kanaga, Bobrof, Gareloi, Segula, and Kiska, suggestive of landslide debris. Simrad EM300 multibeam sonar data, acquired in 2005, show that these areas consist of discrete large blocks strewn across the seafloor, supporting the landslide interpretation from the GLORIA data. A debris-avalanche deposit north of Kiska Island (177.6?? E, 52.1?? N) was fully mapped by EM300 multibeam revealing a hummocky surface that extends 40??km from the north flank of the volcano and covers an area of ??? 380??km2. A 24-channel seismic reflection profile across the longitudinal axis of the deposit reveals a several hundred-meter-thick chaotic unit that appears to have incised into well-bedded sediment, with only a few tens of meters of surface relief. Edifice failures include thin-skinned, narrow, Stromboli-style collapse as well as Bezymianny-style collapse accompanied by an explosive eruption, but many of the events appear to have been deep-seated, removing much of an edifice and depositing huge amounts of debris on the sea floor. Based on the absence of large pyroclastic sheets on the islands, this latter type of collapse was not accompanied by large eruptions, and may have been driven by gravity failure instead of magmatic injection. Young volcanoes in the central and western portions of the arc (177?? E to 175?? W) are located atop the northern edge of the ??? 4000-m-high Aleutian ridge. The position of the Quaternary stratocones relative to the

  1. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2007-02-28

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  2. A comparative study of the properties of TiN films deposited by MAIP and FCAP

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this study two types of TiN films were prepared, one using the filtered cathodic arc plasma (FC AP) technique with an in-plane "S" filier, and the other using the multi-arc ion-plating (MAIP), and both deposited under the same parameters. Comparisons of the texture, hardness, roughness, tribological and electrochemical corrosion behaviors of the two types of TiN films were given. The TiN films obtained by the FCAP technology were found to be highly uniform, smooth and macroparticle-free. The TiN films deposited by FCAP had a (111) preferred orientation, while there was no texture in the films deposited by MAIP. Under low load the two kinds of TiN coatings had very different wear mechanisms; the films of FCAP had a lower wear rate and friction coefficient compared with the TiN films deposited by the MAIP technique. The dense and hole-free structure of TiN films of FCAP could effectively avoid the avalanche of TiN films from the substrate during corrosion tests.

  3. A Novel Arc Fault Detector for Early Detection of Electrical Fires

    Science.gov (United States)

    Yang, Kai; Zhang, Rencheng; Yang, Jianhong; Liu, Canhua; Chen, Shouhong; Zhang, Fujiang

    2016-01-01

    Arc faults can produce very high temperatures and can easily ignite combustible materials; thus, they represent one of the most important causes of electrical fires. The application of arc fault detection, as an emerging early fire detection technology, is required by the National Electrical Code to reduce the occurrence of electrical fires. However, the concealment, randomness and diversity of arc faults make them difficult to detect. To improve the accuracy of arc fault detection, a novel arc fault detector (AFD) is developed in this study. First, an experimental arc fault platform is built to study electrical fires. A high-frequency transducer and a current transducer are used to measure typical load signals of arc faults and normal states. After the common features of these signals are studied, high-frequency energy and current variations are extracted as an input eigenvector for use by an arc fault detection algorithm. Then, the detection algorithm based on a weighted least squares support vector machine is designed and successfully applied in a microprocessor. Finally, an AFD is developed. The test results show that the AFD can detect arc faults in a timely manner and interrupt the circuit power supply before electrical fires can occur. The AFD is not influenced by cross talk or transient processes, and the detection accuracy is very high. Hence, the AFD can be installed in low-voltage circuits to monitor circuit states in real-time to facilitate the early detection of electrical fires. PMID:27070618

  4. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    Science.gov (United States)

    Niu, Chunping; Ding, Juwen; Yang, Fei; Dong, Delong; Rong, Mingzhe; Xu, Dan

    2016-05-01

    In this paper, a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB). The distributions of pressure, temperature, gas flow and current density of the arc plasma in the arc region are calculated, and the factors influencing the commutation process are analyzed according to the calculated results. Based on the airflow in the arc chamber, the causes of arc commutation asynchrony and the back commutation are investigated. It indicates that a reasonable contact space design is crucial to a successful arc commutation process. To verify the simulation results, the influence of contact space on arc voltage and arc commutation is tested. This research can provide methods and references to the optimization of ACB design. supported by National Key Basic Research Program of China (973 Program) (Nos. 2015CB251002, 6132620303) and National Natural Science Foundation of China (Nos. 51221005, 51377128, 51577144), and Science and Technology Project Through Grid State Corporation (No. SGSNKYOOKJJS1501564)

  5. Electroless nickel alloy deposition on SiO2 for application as a diffusion barrier and seed layer in 3D copper interconnect technology.

    Science.gov (United States)

    Kim, Tae-Yoo; Son, Hwa-Jin; Lim, Seung-Kyu; Song, Young-Il; Park, Hwa-Sun; Suh, Su-Jeong

    2014-12-01

    Electroless Ni-P films were investigated with the aim of application as barrier and seed layers in 3D interconnect technology. Different shapes of blind-via holes were fabricated with a deep reactive ion etcher and SiO2 formed on these holes as an insulating layer. The surface of the substrate has been made hydrophilic by O2 plasma treatment with 100 W of power for 20 min. Electroless Ni-P films were deposited as both a diffusion barrier and a seed layer for Cu filling process. Prior to plating, substrates were activated in a palladium chloride solution after sensitization in a tin chloride solution with various conditions in order to deposit uniform films in TSV. After the formation of the electroless barrier layer, electro Cu was plated directly on the barrier layer. Ni-P films fabricated in blind-via holes were observed by scanning electron microscope. Energy dispersive spectroscopy line scanning was carried out for evaluating the diffusion barrier properties of the Ni-P films. The electroless Ni-P layer worked well as a Cu diffusion barrier until 300 degrees C. However, Cu ions diffused into barrier layer when the annealing temperature increases over 400 degrees C. PMID:25971093

  6. Dynamic Resource Allocation with the arcControlTower

    Science.gov (United States)

    Filipčič, A.; Cameron, D.; Nilsen, J. K.

    2015-12-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience of running many millions of ATLAS jobs on it.

  7. CHEP2015: Dynamic Resource Allocation with arcControlTower

    CERN Document Server

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job mangement system (Panda) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience...

  8. Dynamic Resource Allocation with the arcControlTower

    CERN Document Server

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experienc...

  9. Observation of the glow-to-arc transitions

    Science.gov (United States)

    Watanabe, Shigeru; Saito, Shigeki; Takahashi, Kunio; Onzawa, Tadao

    2002-10-01

    Researches of the glow-to-arc transitions have been required for a new development of the welding technology in low current. It is important to clarify the characteristics of plasma in the transitions because there have been few reports investigated the transitions in detail. The glow-to-arc transitions were observed in argon at atmospheric pressure. The Th-W electrodes of 1 mm in a diameter are used. Both of the electrodes are needle-shaped and set in a quartz tube coaxially. Plasma is generated between the electrodes with the gap spacing of 1 mm. A DC power supply has been applying constant voltage of 600 V during the discharge. A high-speed camera is used to record the images of plasma in the transitions with the measurement of voltage and current between the electrodes. As a result, two things were confirmed for the behavior of the glow-to-arc transition. First, plasma extended over the cathode surface in the transition from the glow to the arc. Second, temperature in the tip of the cathode would increase gradually during the glow and decrease during the arc.

  10. Atmospheric Deposition of Heavy Metals in Serbia Studied by Moss Biomonitoring, Neutron Activation Analysis and GIS Technology

    CERN Document Server

    Frontasyeva, M V; Kumar, M; Matavuly, M; Pavlov, S S; Radnovic, D; Steinnes, E

    2002-01-01

    The results of a pilot study on atmospheric deposition of heavy metals and other trace elements using the moss biomonitoring technique in the northern part of Serbia and some areas of Bosnia are presented. Samples of Hypnum cupressiforme along with some other moss types were collected at 92 sites during the summer of 2000. A total of 44 elements were determined by instrumental neutron activation analysis using epithermal neutrons. The observed levels of Cu, Zn, As, Ag, Cd, In, Sb, etc. in the area surrounding the town of Bor (Serbia) are comparable to those reported from similar industrial areas in other countries such as the Copper Basin in Poland and the South Urals of Russia. In the same region the maximum Se and Mo concentrations are the highest ever recorded in biomonitoring studies using mosses. High median concentrations of Fe and Ni in Serbian mosses are associated with a crustal component as apparent from factor analysis of the moss data. This component could be a result of windblown soil dust (most ...

  11. Technology assessment: environmental, health, and safety impacts associated with oil recovery from US tar-sand deposits

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.I.; Anspaugh, L.R.; Ricker, Y.E.

    1981-10-13

    The tar-sand resources of the US have the potential to yield as much as 36 billion barrels (bbls) of oil. The tar-sand petroleum-extraction technologies now being considered for commercialization in the United States include both surface (above ground) systems and in situ (underground) procedures. The surface systems currently receiving the most attention include: (1) thermal decomposition processes (retorting); (2) suspension methods (solvent extraction); and (3) washing techniques (water separation). Underground bitumen extraction techniques now being field tested are: (1) in situ combustion; and (2) in situ steam-injection procedures. At this time, any commercial tar-sand facility in the US will have to comply with at least 7 major federal regulations in addition to state regulations; building, electrical, and fire codes; and petroleum-industry construction standards. Pollution-control methods needed by tar-sand technologies to comply with regulatory standards and to protect air, land, and water quality will probably be similar to those already proposed for commercial oil-shale systems. The costs of these systems could range from about $1.20 to $2.45 per barrel of oil produced. Estimates of potential pollution-emisson levels affecting land, air, and water were calculated from available data related to current surface and in situ tar-sand field experiments in the US. These data were then extrapolated to determine pollutant levels expected from conceptual commercial surface and in situ facilities producing 20,000 bbl/d. The likelihood-of-occurrence of these impacts was then assessed. Experience from other industries, including information concerning health and ecosystem damage from air pollutants, measurements of ground-water transport of organic pollutants, and the effectiveness of environmental-control technologies was used to make this assessment.

  12. Technological characterization of a mineral deposit. A case study: the niobium of Catalao I, Goias State, Brazil

    International Nuclear Information System (INIS)

    This thesis presents a contribution to the subject of ore technological characterization integrated to orebody context, regarding sample, ore characteristics, ore types definition and distribution through the mineral occurrence, and ore reserves modeling using technological parameters. A professional experience in this specialization based a conceptual discussion of the matter, supported by a practical approach. The initial approach is the subject definition, and it's importance for technological and economical feasibility studies, in all phases of mining research and development, as a tool for beneficiation alternatives definition. The multidisciplinary aspect of the knowledge involved for ore characterization is remarked, considering that is an interface segment to be conduced interactively with others. It is an applied mineralogy, that needs some geological and some ore dressing imputes. After the general considerations about importance and applicability, it follows a methodological approach of laboratory procedures and analytical techniques, as a result of practical experience acquired in the study of several ores. The main points discussed are related with criterion to organized laboratory preparation scheme and to select appropriated analytical techniques, without detailing them, for what some specialized bibliography is indicated. Finalizing the theoretical explanation, there is a concise description about computers resources for 3D orebody modeling, and integrated software applied for geology and mining. For illustration, it is exposed a complex ore case study: niobium mineralization associated with the alkaline-carbonatitic occurrence of Catalao I, located in Goias State, Brazil. Besides the explanation of laboratory procedures and methods applied, results treatment and interpretation are emphasized, under both characterization and economic point of view. (author)

  13. The evaluation of geological-technological aspects of ecological safety provision during fieldwork and operation in the Caspian Sea hydrocarbon deposits

    International Nuclear Information System (INIS)

    Full text:The Caspian sea-lake (CS) as a potential source of hydrocarbons (HC) organically enters as a component the united Volga-Ural oil-gas-bearing province of the Caspian region. Accordingly, sea itself and adjoining land form the united geo-ecological system. Its preservation in many ways depends on condition of the whole basin. The situation is also complicated because coast and waters in the area are divided between five states each of which is oil and gas producing. To give full estimation of geological-technological aspects of ecological safety provision during fieldwork and operation of CS hydrocarbon deposits will take the long-term efforts of big group of scientists of different specialty. World Ocean what in its turn softens the ecological load. Besides, unlike the Gulf of Mexico, production of oil Caspian waters has very old history and already at the beginning of the XX century the fight with its contamination started. There are to ways in which HC pollution of the CS occurs. The preliminary analysis of possibilities of estimation geological-technological aspects of ecological safety provision during fieldwork and operation in the CS HC deposits shows the enormous complexity and diversity of the problem. During oil transportation in the North Sea and North Atlantic 0,1% of carried and swapped through pipelines fuel gets in the World Ocean. If applied to the CS then when producing 70-80 mln. T. per annum, 70-80 thousands of tons of oil will get in its waters. Accordingly, previous to starting a full-scale Caspian project it is necessary to conduct the complex of independent all-round studies and estimations

  14. Minor arcs for Goldbach's problem

    OpenAIRE

    Helfgott, H. A.

    2012-01-01

    The ternary Goldbach conjecture states that every odd number n>=7 is the sum of three primes. The estimation of sums of the form \\sum_{p\\leq x} e(\\alpha p), \\alpha = a/q + O(1/q^2), has been a central part of the main approach to the conjecture since (Vinogradov, 1937). Previous work required q or x to be too large to make a proof of the conjecture for all n feasible. The present paper gives new bounds on minor arcs and the tails of major arcs. This is part of the author's proof of the ternar...

  15. Mass spectrometry of arcs in SF6 circuit breakers

    Science.gov (United States)

    Rüegsegger, W.; Meier, R.; Kneubühl, F. K.; Schötzau, H. J.

    1985-07-01

    Today, SF6 is used to a great extent as insulating and arc-quenching medium in high-voltage gas-blast circuit breakers. The arcing in SF6 during current interruption forms decomposition products. These can influence the arc-quenching properties of the circuit breaker. Furthermore, they can cause corrosion of the circuit breaker housing. In this comprehensive study we present results obtained for the first time from a direct mass spectrometric investigation of the exhaust gases of a high pressure SF6 arc in a model circuit breaker. Our mass spectrometric system consists of a time-of-flight mass spectrometer (TOFMS) equipped with a molecular beam sampling systems. This device allows us to measure mass spectra of high pressure sources with a time resolution of up to 10,000 spectra per second. We have determined the formation rate of the most abundant decomposition products in a SF6 arc at 1 bar. These products are SF4, CF4, WF6, SOF2, SO2, CS2 S2F2 and HF. The fast detection time inherent to our system permits also the determination of the formation of SF4, which is 0.45 0.50 Vol. %/(kJ/1SF6). In addition, we have studied the influence of water and oxygen impurities which are responsible for the production of highly corrosive HF. Finally, we have considered the influence of the thermal degradation of teflon (P.T.F.E.), which is used as nozzle and insulating material in circuit breakers. On this occasion we have demonstrated that CF4, which exhibits dielectric properties similar to SF6, is the main decomposition product formed from teflon. However, we have found that besides CF4 also excess carbon is formed, which is deposited on insulators of the model circuit breaker. Our time-resolved mass spectra reveal that the CF4 production from teflon is delayed by a few milliseconds with respect to the SF6 dissociation in the arc. This delay can influence the interrupting process of the circuit breaker by changing the plasma composition during the arcing period. Although our

  16. Atmospheric pressure arc discharge with ablating graphite anode

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, V. A. [Keiser University, Fort Lauderdale Campus, FL, 33309, USA; Raitses, Y. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2015-05-18

    The anodic carbon arc discharge is used to produce carbon nanoparticles. Recent experiments with the carbon arc at atmospheric pressure helium demonstrated the enhanced ablation rate for narrow graphite anodes resulting in high deposition rates of carbonaceous products on the copper cathode (Fetterman et al 2008 Carbon 46 1322–6). The proposed model explains these results with interconnected steady-state models of the cathode and the anode processes. When considering cathode functioning, the model predicts circulation of the particles in the near-cathode region: evaporation of the cathode material, ionization of evaporated atoms and molecules in the near-cathode plasma, return of the resulting ions to the cathode, surface recombination of ions and electrons followed again by cathode evaporation etc. In the case of the low anode ablation rate, the ion acceleration in the cathode sheath provides the major cathode heating mechanism. In the case of an intensive anode ablation, an additional cathode heating is due to latent fusion heat of the atomic species evaporated from the anode and depositing at the cathode. Using the experimental arc voltage as the only input discharge parameter, the model allows us to calculate the anode ablation rate. A comparison of the results of calculations with the available experimental data shows reasonable agreement.

  17. Axisymmetric arc in a supersonic nozzle

    International Nuclear Information System (INIS)

    Axisymmetric arc burning in a supersonic nozzle has wide technical applications (eg in gas blast circuit breaker, arc heaters etc.). Mathematical modelling of such an arc is usually based on boundary-layer assumption which assumes a known pressure distribution imposed on the arc or based on the integral method of arc analysis. Thus, the flow outside of the arc's thermal influence is assumed to be one dimensional. In practice, this is not the case as the nozzle is not sufficiently gentle in the axial direction or the presence of the upstream electrode makes the assumption of one-dimensional flow invalid. The purpose of the present investigation is to model the arc based on Navier-Stokes equations which are modified to take into account of electrical power input and radiation transport. The arcing gas is SF6, the transport properties of which (electrical conductivity, viscosity, thermal conductivity etc.) are highly nonlinear functions of temperature but only weakly dependent on the pressure

  18. Submarine Arc Volcanism in the Southern Mariana Arc: Results of Recent ROV studies

    Science.gov (United States)

    Nichols, A. R.; Tamura, Y.; Stern, R. J.; Embley, R. W.; Hein, J. R.; Jordan, E.; Ribeiro, J. M.; Sica, N.; Kohut, E. J.; Whattam, S. A.; Hirahara, Y.; Senda, R.; Nunokawa, A.

    2009-12-01

    The submarine Diamante cross-arc volcanoes (~16°N) and the Sarigan-Zealandia Bank Multi-Volcano Complex (SZBMVC; ~16°45’N), north and south, respectively, of Anatahan Island in the southern Mariana Arc, were studied during several dives in June 2009 using the ROV Hyper-Dolphin, cruise NT09-08 (R/V Natsushima); neither has been studied in detail before. The data collected provide a new perspective on how the subduction factory operates to complement previous studies on other cross-arc volcanic chains in the Izu-Bonin-Mariana Arc. The Diamante complex consists of three major edifices, two cones (West and Central Diamante) and a more complex caldera-like edifice at the volcanic front (East Diamante). West and Central Diamante are basaltic volcanoes but East Diamante has a more complex history. Our studies indicate initial construction of a basaltic volcano. Magmatic evolution led to a violent caldera-forming and quieter dome-building events. Post-caldera quiescence allowed a carbonate platform to grow, now preserved on the eastern caldera wall. Felsic magma or hot rock provides a heat source for an active hydrothermal field associated with felsic domes in the caldera, which NOAA investigators discovered in 2004. A new type of hydrothermal deposit was discovered in the hydrothermal field, consisting of large sulfide-sulfate mounds topped by bulbous constructions of low-temperature Fe and Mn oxides. Vents on the mounds were observed to emit shimmering water. The SZBMVC consists of six closely spaced edifices whose loci are aligned along two parallel trends, one along the volcanic front (Zealandia Bank, Sarigan and South Sarigan), and one about 15 km west towards the rear-arc (Northwest Zealandia, West Zealandia and West Sarigan). Zealandia Bank dives revealed that, as with East Diamante, initial activity was basaltic and became more evolved with time. The western half of Zealandia Bank is dominated by felsic lavas centered on a small (~2 km diameter) caldera and

  19. Treatment of simulated INEL buried wastes using a graphite electrode DC arc furnace

    International Nuclear Information System (INIS)

    A program has been established under the auspices of the Department of Energy (DOE), Office of Technology Development (OTD), to develop the graphite electrode DC arc technology for the application of treating buried heterogenous solid wastes. A three way open-quotes National Laboratory-University-Industryclose quotes partnership was formed to develop this technology in the most timely and cost effective manner. This program is presently testing a newly fabricated pilot-scale DC arc furnace with associated diagnostics at the Plasma Fusion Center at the Massachusetts Institute of Technology. Initial testing in a smaller engineering scale furnace has established the viability of this technology for the treatment of solid heterogeneous wastes. Two diagnostic tools were developed under this program which support the evaluation of the DC arc technology. The diagnostics provide for both spatially resolved temperature measurements within the furnace and real time monitoring of the furnace metal emissions

  20. Atmospheric deposition of heavy metals in transilvanian plateau of romania studied by the moss bio monitoring Technique employing nuclear and related analytical Techniques and gis technology

    International Nuclear Information System (INIS)

    This paper presents data for 39 elements of 69 moss samples (Hypnum cupressiforme) collected in the Transilvanian Plateau of Romania. This results have obtained in the framework of the project Atmospheric Deposition of Heavy Metals in Rural and Urban Areas of Romania Studied by the Moss Bio monitoring Technique Employing Nuclear and Related Analytical Techniques and GIS Technology carried out under the auspices of the International Atomic Energy Agency, Vienna.The samples collected have been analyzed by ENAA with the exception of Cu, Cd, and Pb which were determined by AAS. IAEA certified materials were used to ensure the quality of the measurements. The regional concentration variations of selected elements are presented in the form of maps constructed by GIS technology. Extremely high values are observed for elements such as Cu, Zn, As and Sb in parts of this territory affected by local metal industries. The levels are among the highest observed in the world, and could be partly responsible for the unfortunate health situation in some of these areas

  1. Craniospinal irradiation using Rapid Arc

    Energy Technology Data Exchange (ETDEWEB)

    Fandino, J. M.; Silva, M. C.; Marino, A.; Candal, A.; Diaz, I.; Fernandez, C.; Gesto, C.; Izquierdo, P.; Losada, C.; Poncet, M.; Soto, M.; Triana, G.

    2013-07-01

    Cranio-Spinal Irradiation is technically very challenging, historically field edge matching is needed because of the mechanical limitations of standard linear accelerators. The purpose of this study is to assess the Volumetric Arc Therapy as a competitive technique for Cranio-Spinal Irradiation compared to the conventional 3D Conformal Radiotherapy technique. (Author)

  2. A rotating arc plasma invertor

    International Nuclear Information System (INIS)

    A device is described for the inversion of direct current to alternating current. The main feature is the use of a rotating plasma arc in crossed electric and magnetic fields as a switch. This device may provide an economic alternative to other inversion methods in some circumstances

  3. The next-generation ARC middleware

    DEFF Research Database (Denmark)

    Appleton, O.; Cameron, D.; Cernak, J.;

    2010-01-01

    The Advanced Resource Connector (ARC) is a light-weight, non-intrusive, simple yet powerful Grid middleware capable of connecting highly heterogeneous computing and storage resources. ARC aims at providing general purpose, flexible, collaborative computing environments suitable for a range of uses...... the next-generation ARC middleware, implemented as Web Services with the aim of standard-compliant interoperability....

  4. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    on Ohm’s law indicates that the critical length of alternating current (AC) gliding arc discharge columns can be larger than that of a corresponding direct current (DC) gliding arc. This finding is supported by previously published images of AC and DC gliding arcs. Furthermore, the analysis shows...

  5. Making Conductive Polymers By Arc Tracking

    Science.gov (United States)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  6. Along-arc geochemical and isotopic variations in Javanese volcanic rocks: 'crustal' versus 'source' contamination at the Sunda arc, Indonesia

    Science.gov (United States)

    Handley, H.; Blichert-Toft, J.; Turner, S.; Macpherson, C. G.

    2012-12-01

    Understanding the genesis of volcanic rocks in subduction zone settings is complicated by the multitude of differentiation processes and source components that exert control on lava geochemistry. Magma genesis and evolution at the Sunda arc is controlled and influenced by 1) along arc changes in the composition and thickness of the overriding Eurasian plate, 2) the variable age of the subducting oceanic crust and, 3) changes in the type and amount of sediment deposited on the subducting plate. Along-arc changes in geochemistry have long been recognised in the Sunda arc (Whitford, 1975), but debate still prevails over the cause of such variations and the relative importance of shallow (crustal) versus deep (subduction) contamination at the Sunda arc, Indonesia. Detailed study of individual Sunda arc volcanic centres is, therefore, a prerequisite in order to establish the relative importance and contributions of various potential source components and composition modifying differentiation processes at individual volcanoes, prior to an along arc comparative petrogenetic investigation. We present new radiogenic isotope data for Javanese volcanoes, which is combined with our recently published (Handley et al., 2007; Handley et al., 2008, Handley et al., 2010; Handley et al., 2011) geochemical and isotopic data of Javanese volcanic rocks along with data from other detailed geochemical studies to establish whether variable contributions from the subducting slab, or a change in crustal architecture of the overriding plate, best explain along-arc variations in isotope ratios and trace element characteristics. In West and Central Java Sr isotope ratios of the volcanic rocks broadly correlate with inferred lithospheric thickness implicating a shallow level control on isotopic composition. However, key trace element ratios combined with Hf isotope data indicate that the subducted slab and slab thermal regime also exert major control on the composition of the erupted Javanese

  7. Electroless nickel plating of arc discharge synthesized carbon nanotubes for metal matrix composites

    Science.gov (United States)

    Jagannatham, M.; Sankaran, S.; Prathap, Haridoss

    2015-01-01

    Electroless nickel (EN) plating was performed on arc discharge synthesized multiwalled carbon nanotubes for various deposition times. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Raman spectroscopy characterization techniques are used to identify the presence of nickel deposition on the carbon nanotubes (CNTs) and the degree of graphitization. The results indicate that impurities are less in the purified CNTs as compared to raw carbon soot. Increasing deposition time up to 60 min increases uniform deposition of nickel throughout the length of the CNTs. However, for deposition time longer than 60 min, nickel particles are seen separated from the surface of the CNTs. Uniformly coated nickel CNTs throughout their length are potential candidates for reinforcements in composite materials. Magnetic properties of the nickel coated CNTs, with deposition time of 30 and 60 min were also evaluated. The magnetic saturation of nickel coated CNTs with deposition time of 30 min is less compared to nickel coated CNTs with deposition time of 60 min.

  8. Micromachining of large area amorphous carbon membranes prepared by filtered cathodic vacuum arc technique

    Science.gov (United States)

    Liujiang, Yu; Tay, B. K.; Sheeja, D.; Fu, Y. Q.; Miao, J. M.

    2004-02-01

    Currently, there is a strong drive to make micro-electro-mechanical system (MEMS) devices from higher performance materials such as diamond-like carbon or amorphous carbon (a-C) films, due to their excellent tribological properties, low-stiction (hydrophobic) surfaces, chemical inertness and high elastic modulus, compared to that of Si. The hydrogen free a-C films prepared, by Nanyang Technological University's (NTUs) patented filtered cathodic vacuum arc (FCVA) technique, at 100 eV exhibits high fraction of tetrahedral (sp 3 bonded) carbon atoms. These films exhibit relatively high hardness, stiffness and wear resistance in addition to low friction and stiction behaviour. However, the primary problem lies in the large intrinsic compressive stress induced during the deposition process. By making use of high substrate pulse bias, we have successfully produced low stress, thick a-C films. The films were then characterised using different equipments to evaluate the stress, microstructure and morphological roughness. Large area a-C membranes, of 2 mm×2 mm in size, have also been fabricated using the low stress, thick film deposited by the above method.

  9. Micromachining of large area amorphous carbon membranes prepared by filtered cathodic vacuum arc technique

    Energy Technology Data Exchange (ETDEWEB)

    Liujiang, Yu; Tay, B.K.; Sheeja, D.; Fu, Y.Q.; Miao, J.M

    2004-02-29

    Currently, there is a strong drive to make micro-electro-mechanical system (MEMS) devices from higher performance materials such as diamond-like carbon or amorphous carbon (a-C) films, due to their excellent tribological properties, low-stiction (hydrophobic) surfaces, chemical inertness and high elastic modulus, compared to that of Si. The hydrogen free a-C films prepared, by Nanyang Technological University's (NTUs) patented filtered cathodic vacuum arc (FCVA) technique, at 100 eV exhibits high fraction of tetrahedral (sp{sup 3} bonded) carbon atoms. These films exhibit relatively high hardness, stiffness and wear resistance in addition to low friction and stiction behaviour. However, the primary problem lies in the large intrinsic compressive stress induced during the deposition process. By making use of high substrate pulse bias, we have successfully produced low stress, thick a-C films. The films were then characterised using different equipments to evaluate the stress, microstructure and morphological roughness. Large area a-C membranes, of 2 mmx2 mm in size, have also been fabricated using the low stress, thick film deposited by the above method.

  10. Use of a Low-Pressure Non-Self-Sustained Arc Discharge for Plasma Ion Treatment of Materials

    International Nuclear Information System (INIS)

    An efficient method for producing low-temperature gas plasmas in large vacuum volumes is based on the initiation and operation of a low-pressure non-self-sustained arc discharge with a combined cathode including a hot cathode and a hollow cathode. For this type of a discharge, the inner walls of the working vacuum chamber play the role of a hollow anode. In the range from 10-1 to 1 Pa, this method makes it possible to produce plasmas of both inert and reactive gases of density 109 - 1010 cm-3 uniform within 20% with respect to the average value in volumes of about 1 m3. This paper describes major applications of this type of plasma in technological processes, such as: finish surface cleaning of materials and articles in vacuum; plasma ion nitriding of steels and alloys; plasma-assisted deposition of functional coatings on materials and articles. (author)

  11. Measurements of the critical inclusion size for arcing and macroparticle ejection from aluminum sputtering targets

    International Nuclear Information System (INIS)

    Arcing during sputtering is a significant cause of defect generation during sputter deposition of thin films. We studied the effect of dielectric inclusion size on the propensity for arcing while sputtering aluminum targets in argon at power densities ranging from 8 to near 60 W/cm2. We found that there is a critical inclusion size required for arcing to occur. The critical size for an Al2O3 inclusion in an aluminum-sputtering target in an argon plasma is 440±160 μm. Inclusions with sizes above this critical value readily induce arcing and macroparticle ejection during sputtering. Inclusions below this critical size do not cause arcing or macroparticle ejection. We also found that the inclusion critical size was not sensitive to the sputtering power density. When the inclusion size exceeds the critical value the plasma boundary over the inclusion is deformed by the charge accumulating on the dielectric inclusion and the plasma positive column diffuses toward the target leading to a bipolar arc. Inclusions below the critical size do not distort the dark space to an extent great enough to permit bipolar arc formation. Our proposed model predicts that the critical inclusion size depends upon the sheath thickness, which ranged between 300 and 600 μm for the experimental conditions used in this study

  12. Arc-based smoothing of ion beam intensity on targets

    International Nuclear Information System (INIS)

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  13. Arc-based smoothing of ion beam intensity on targets

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Alex [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States) and The Virtual National Laboratory for Heavy Ion Fusion Science (United States)

    2012-06-15

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ('heavy-ion fusion'). Here, we consider an approach to such smoothing that is based on rapidly 'wobbling' each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  14. Arc-based smoothing of ion beam intensity on targets

    Science.gov (United States)

    Friedman, Alex

    2012-06-01

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ("heavy-ion fusion"). Here, we consider an approach to such smoothing that is based on rapidly "wobbling" each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  15. INFLUENCE OF VACUUM ARC PLASMA EVAPORATOR CATHODE GEOMETRY OF ON VALUE OF ADMISSIBLE ARC DISCHARGE CURRENT

    Directory of Open Access Journals (Sweden)

    I. A. Ivanou

    2015-01-01

    Full Text Available An analysis of main design parameters that determine a level of droplet formation intensity at the generating stage of plasma flow has been given in the paper. The paper considers the most widely used designs of water cooled consumable cathodes. Ti or Ti–Si and Fe–Cr alloys have been taken as a material for cathodes. The following calculated data: average ionic charge Zi for titanium plasma +1.6; for «titanium–silicon plasma» +1.2, an electronic discharge 1.6022 ⋅ 10–19 C, an ion velocity vi = 2 ⋅ 104 m/s, an effective volt energy equivalent of heat flow diverted in the cathode Uк = 12 V, temperature of erosion cathode surface Тп = 550 К; temperature of the cooled cathode surface То = 350 К have been accepted in order to determine dependence of a maximum admissible arc discharge current on cathode height. The calculations have been carried out for various values of the cathode heights hк (from 0.02 to 0.05 m. Diameter of a target cathode is equal to 0.08 m for a majority of technological plasma devices, therefore, the area of the erosion surface is S = 0.005 m2.A thickness selection for a consumable target cathode part in the vacuum arc plasma source has been justified in the paper. The thickness ensures formation of minimum drop phase in the plasma flow during arc cathode material evaporation. It has been shown that a maximum admissible current of an arc discharge is practically equal to the minimum current of stable arcing when thickness of the consumable cathode part is equal to 0.05 m. The admissible discharge current can be rather significant and ensure high productivity during coating process with formation of relatively low amount of droplet phase in the coating at small values of hк.

  16. Effect of Na2WO4 on Growth Process and Corrosion Resistance of Micro-arc Oxidation Coatings on 2A12 Aluminum Alloys in CH3COONa Electrolyte

    Science.gov (United States)

    Lin, Zhaoqing; Yu, Huijun; He, Siyu; Wang, Diangang; Chen, Chuanzhong

    2016-01-01

    Ceramic coatings were deposited on 2A12 aluminum alloys using micro-arc oxidation (MAO) technology in CH3COONa-Na2WO4 electrolyte. The MAO process was studied by recording the current-time curve. The influences of Na2WO4 concentrations on the coatings in CH3COONa electrolyte were investigated. The results show that the Na2WO4 concentrations affect the MAO process and performances of the coatings directly. Na2WO4 in excess is harmful for the formation of Al2O3 in this electrolyte. The corrosion resistance was enhanced with the decrease of Na2WO4 concentration.

  17. Relationship between arc voltage current and arc length in TIG welding

    International Nuclear Information System (INIS)

    The relationship between arc voltage, arc length and current in Tungsten Inert Gas welding has been investigated. It was not possible to determine a correlation between arc voltage, current and arc length because of the inherent variability in the experimental results. A typical value for the error in controlling the arc length using arc voltage was calculated and found to be ± 0.5mm. The variation in arc voltage at constant conditions has two components, long term and short term. Long term is the variation in voltage between welds, short term is voltage variation within a few seconds. Both are about 5% of the total arc voltage. Since only a fraction of the arc voltage depends on arc length, this leads to a much larger variation in arc length if Arc Voltage Control (AVC) is used to control arc length (about 15% in each case at 3mm arc length). A weld procedure based on AVC is likely to yield a different variability in weld bead geometry from one based on constant arc length. (author)

  18. Simulation of Magnetically Dispersed Arc Plasma

    Institute of Scientific and Technical Information of China (English)

    白冰; 查俊; 张晓宁; 王城; 夏维东

    2012-01-01

    Magnetically dispersed arc plasma exhibits typically dispersed uniform arc column as well as diffusive cathode root and diffusive anode root. In this paper magnetically dispersed arc plasma coupled with solid cathode is numerically simulated by the simplified cathode sheath model of LOWKE . The numerical simulation results in argon show that the maximum value of arc root current density on the cathode surface is 3.5×10^7 A/m^2), and the maximum value of energy flux on the cathode surface is 3× 10^7 J/m^2, both values are less than the average values of a contracted arc, respectively.

  19. Parametric Study on Arc Behavior of Magnetically Diffused Arc

    Science.gov (United States)

    Chen, Tang; Li, Hui; Bai, Bing; Liao, Mengran; Xia, Weidong

    2016-01-01

    A model coupling the plasma with a cathode body is applied in the simulation of the diffuse state of a magnetically rotating arc. Four parametric studies are performed: on the external axial magnetic field (AMF), on the cathode shape, on the total current and on the inlet gas velocity. The numerical results show that: the cathode attachment focuses in the center of the cathode tip with zero AMF and gradually shifts off the axis with the increase of AMF; a larger cathode conical angle corresponds to a cathode arc attachment farther away off axis; the maximum values of plasma temperature increase with the total current; the plasma column in front of the cathode tip expands more severely in the axial direction, with a higher inlet speed; the cathode arc attachment shrinks towards the tip as the inlet speed increases. The various results are supposed to be explained by the joint effect of coupled cathode surface heating and plasma rotating flow. supported by National Natural Science Foundation of China (Nos. 11475174, 11035005 and 50876101)

  20. Device for film deposition and implantation of ions inside pipes of low diameter

    International Nuclear Information System (INIS)

    Two principally new devices, which can be applied to deposit coatings inside the pipes of low diameter, have been developed. The thickness of coatings and films can be varied. To deposit coatings of a low thickness (about 2 nm) on inside pipe walls using a vacuum-arc source and a sputtering device, which is composed of the pipe applied for anode cooling, the constant magnet, the magnetic circuit, the anode, the cathode, the pipe subjected for coating deposition, the cathode holder, etc. Using this device, we have deposited TiC, Ta, Cr, TiN coatings of various thickness ranging from scores of nano-meters to several micro-meters and with very good adhesion to the substrate. To increase adhesion, we applied 10 to 20 kV voltage during ion implantation to the substrate. To study element and structure composition, we applied RBS, TEM, SEM, XRD analyses, micro-hardness, wear resistance tests and also those for corrosion resistance in acid media. Another version of the source was based on the pulsed plasma-detonation technology and applied an evaporating electrode (for implantation) and a powder, which was injected into a plasma jet. The jet velocity reached several kilometers per second. Current of several kilo-amps passed through the plasma jet and increased its energy. The produced in this way coating thickness reached 30 to 400 micro-meter. Application of the vacuum-arc source for subsequent coating deposition allowed us to improve the servicing characteristics of surface layers. We have deposited NiAl, CoAl, A12O3, WC-Co, Hastelloy and stainless steel SS316L

  1. MO-H-19A-02: Investigation of Modulated Electron Arc (MeArc) Therapy for the Treatment of Scalp Tumors

    International Nuclear Information System (INIS)

    Purpose: Electron arc therapy has long been proposed as the most suitable technique for the treatment of superficial tumors that follow circularly curved surfaces. However it was challenged by unsuitability of the conventional applicators and the lack of adequate 3-D dose calculation tools for arc electron beams in the treatment planning systems (TPS). Now with the availability of an electron specific multi-leaf collimator (eMLC) and an in-house Monte Carlo (MC) based TPS, we were motivated to investigate more advanced modulated electron arc (MeARC) therapy and its beneficial outcome. Methods: We initiated the study by a film measurement conducted in a head and neck phantom, where we delivered electron arcs in a step and shoot manner using the light field as a guide to avoid fields abutments. This step was done to insure enough clearance for the arcs with eMLC. MCBEAM and MCPLAN MC codes were used for the treatment head simulation and phantom dose calculation, respectively. Treatment plans were generated for targets drawn in real patient CTs and head and neck phantom. We utilized beams eye view available from a commercial planning system to create beamlets having same isocenter and adjoined at the scalp surface. Then dose-deposition coefficients from those beamlets were calculated for all electron energies using MCPLAN. An in-house optimization code was then used to find the optimum weights needed from individual beamlets. Results: MeARC showed a nicely tailored dose distribution around the circular curved target on the scalp. Some hot spots were noticed and could be attributed to fields abutment problem owing to the bulging nature of electron profiles. Brain dose was shown to be at lower levels compared to photon treatment. Conclusion: MeARC was shown to be a promising modality for treating scalp cases and could be beneficial to all superficial tumors with a circular curvature

  2. MO-H-19A-02: Investigation of Modulated Electron Arc (MeArc) Therapy for the Treatment of Scalp Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Eldib, A [Fox Chase Cancer Center, Philadelphia, PA (United States); Al-Azhar University, Cairo (Egypt); Jin, L; Martin, J; Li, J; Chibani, O; Galloway, T; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2014-06-15

    Purpose: Electron arc therapy has long been proposed as the most suitable technique for the treatment of superficial tumors that follow circularly curved surfaces. However it was challenged by unsuitability of the conventional applicators and the lack of adequate 3-D dose calculation tools for arc electron beams in the treatment planning systems (TPS). Now with the availability of an electron specific multi-leaf collimator (eMLC) and an in-house Monte Carlo (MC) based TPS, we were motivated to investigate more advanced modulated electron arc (MeARC) therapy and its beneficial outcome. Methods: We initiated the study by a film measurement conducted in a head and neck phantom, where we delivered electron arcs in a step and shoot manner using the light field as a guide to avoid fields abutments. This step was done to insure enough clearance for the arcs with eMLC. MCBEAM and MCPLAN MC codes were used for the treatment head simulation and phantom dose calculation, respectively. Treatment plans were generated for targets drawn in real patient CTs and head and neck phantom. We utilized beams eye view available from a commercial planning system to create beamlets having same isocenter and adjoined at the scalp surface. Then dose-deposition coefficients from those beamlets were calculated for all electron energies using MCPLAN. An in-house optimization code was then used to find the optimum weights needed from individual beamlets. Results: MeARC showed a nicely tailored dose distribution around the circular curved target on the scalp. Some hot spots were noticed and could be attributed to fields abutment problem owing to the bulging nature of electron profiles. Brain dose was shown to be at lower levels compared to photon treatment. Conclusion: MeARC was shown to be a promising modality for treating scalp cases and could be beneficial to all superficial tumors with a circular curvature.

  3. Low-fluorine Stockwork Molybdenite Deposits

    Science.gov (United States)

    Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

    2009-01-01

    Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

  4. Models of plasma arc welding

    International Nuclear Information System (INIS)

    A complex model of energy transfer from ionized gas through a weld-pool to a heat affected zone (HAZ) is considered here. The model consists of three sub-models: a model of the arc column with skin layers - sheaths coating electrodes, a model of liquid metal flow in a weld-pool, and a model of coupled thermo-mechanical-metallurgical processes in HAZ. These sub-models are descried in three reports. The first report is devoted to a short review of welding plasma models based mostly on the Magneto-Hydro-Dynamics (MHD) theory successfully applied to the simulation of welding process. This report is illustrated by arc models for TIG and PAW welding. The description of thermal energy transfer between three sub-regions of the complex welding domain refers to a large number of processes observed in gaseous electronics, thermodynamics of reacting gases, electro-dynamics of fluid, micro-metallurgy. (author)

  5. Remote automatic control scheme for plasma arc cutting of contaminated waste

    International Nuclear Information System (INIS)

    The Robotics Development Group at the Savannah River Technology Center has developed and implemented a scheme to perform automatic cutting of metallic contaminated waste. The scheme employs a plasma arc cutter in conjunction with a laser ranging sensor attached to a robotic manipulator called the Telerobot. A software algorithm using proportional control is then used to perturb the robot's trajectory in such a way as to regulate the plasma arc standoff and the robot's speed in order to achieve automatic plasma arc cuts. The scheme has been successfully tested on simulated waste materials and the results have been very favorable. This report details the development and testing of the scheme

  6. Volcano collapse along the Aleutian Ridge (western Aleutian Arc

    Directory of Open Access Journals (Sweden)

    C. Montanaro

    2011-03-01

    Full Text Available The Aleutian Ridge, in the western part of the Aleutian Arc, consists of a chain of volcanic islands perched atop the crest of a submarine ridge with most of the active Quaternary stratocones or caldera-like volcanoes being located on the northern margins of the Aleutian Islands. Integrated analysis of marine and terrestrial data resulted in the identification and characterization of 17 extensive submarine debris avalanche deposits from 11 volcanoes. Two morphological types of deposits are recognizable, elongate and lobate, with primary controls on the size and distribution of the volcanic debris being the volume and nature of material involved, proportion of fine grained material, depth of emplacement and the paleo-bathymetry. Volume calculations show the amount of material deposited in debris avalanches is as much as three times larger than the amount of material initially involved in the collapse, suggesting the incorporation of large amounts of submarine material during transport. The orientation of the collapse events is influenced by regional fault systems underling the volcanoes. The western Aleutian Arc has a significant tsunamigenic potential and communities within the Aleutian Islands and surrounding areas of the North Pacific as well as shipping and fishing fleets that cross the North Pacific may be at risk during future eruptions in this area.

  7. A novel 300 kW arc plasma inverter system based on hierarchical controlled building block structure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.

  8. Zircon Recycling in Arc Intrusions

    Science.gov (United States)

    Miller, J.; Barth, A.; Matzel, J.; Wooden, J.; Burgess, S.

    2008-12-01

    Recycling of zircon has been well established in arc intrusions and arc volcanoes, but a better understanding of where and how zircons are recycled can help illuminate how arc magma systems are constructed. To that end, we are conducting age, trace element (including Ti-in-zircon temperatures; TzrnTi) and isotopic studies of zircons from the Late Cretaceous (95-85 Ma) Tuolumne Intrusive Suite (TIS) in the Sierra Nevada Batholith (CA). Within the TIS zircons inherited from ancient basement sources and/or distinctly older host rocks are uncommon, but recycled zircon antecrysts from earlier periods of TIS-related magmatism are common and conspicuous in the inner and two most voluminous units of the TIS, the Half Dome and Cathedral Peak Granodiorites. All TIS units have low bulk Zr ([Zr]825°C), [Zr] in the TIS is a factor of 2 to 3 lower than saturation values. Low [Zr] in TIS rocks might be attributed to a very limited supply of zircon in the source, by disequilibrium melting and rapid melt extraction [1], by melting reactions involving formation of other phases that can incorporate appreciable Zr [2], or by removal of zircon at an earlier stage of magma evolution. Based on a preliminary compilation of literature data, low [Zr] is common to Late Cretaceous N.A. Cordilleran granodioritic/tonalitic intrusions (typically Tzrnsat [3]. A corollary is that slightly older zircon antecrysts that are common in the inner units of the TIS could be considered inherited if they are derived from remelting of slightly older intrusions. Remelting at such low temperatures in the arc would require a source of external water. Refs: [1] Sawyer, J.Pet 32:701-738; [2] Fraser et al, Geology 25:607-610; [3] Harrison et al, Geology 35:635- 638

  9. DC Arc Plasma Disposal of Printed Circuit Board

    Institute of Scientific and Technical Information of China (English)

    黄建军; 施嘉标; 孟月东; 刘正之

    2004-01-01

    A new solid waste disposal technology setup with DC arc plasma is presented. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled high-temperature pyrolysis, the thermal destruction and recovery process. The results of vitrification of the circuit board is presented. The properties of vitrified product including hardness and leaching test results are presented. The final product (vitrified material) and air emission from the plasma treatment is environmentally acceptable.

  10. DC arc plasma disposal of printed circuit board

    International Nuclear Information System (INIS)

    A new solid waste disposal technology setup with DC arc plasma is presented. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled high-temperature pyrolysis, the thermal destruction and recovery process. The results of vitrification of the circuit board are presented. The properties of vitrified product including hardness and leaching test results are presented. The final product (vitrified material) and air emission from the plasma treatment is environmentally acceptable. (authors)

  11. Minor arcs for Goldbach's problem

    CERN Document Server

    Helfgott, H A

    2012-01-01

    The ternary Goldbach conjecture states that every odd number $n\\geq 7$ is the sum of three primes. The estimation of sums of the form $\\sum_{p\\leq x} e(\\alpha p)$, $\\alpha = a/q + O(1/q^2)$, has been a central part of the main approach to the conjecture since (Vinogradov, 1937). Previous work required $q$ or $x$ to be too large to make a proof of the conjecture for all $n$ feasible. The present paper gives new bounds on minor arcs and the tails of major arcs. For $q\\geq 4\\cdot 10^6$, these bounds are of the strength needed to solve the ternary Goldbach conjecture. Only the range $q\\in \\lbrack 10^5, 4\\cdot 10^6\\rbrack$ remains to be checked, possibly by brute force, before the conjecture is proven for all $n$. The new bounds are due to several qualitative improvements. In particular, this paper presents a general method for reducing the cost of Vaughan's identity, as well as a way to exploit the tails of minor arcs in the context of the large sieve.

  12. Volcanic evolution of the South Sandwich volcanic arc, South Atlantic, from multibeam bathymetry

    Science.gov (United States)

    Leat, Philip T.; Day, Simon J.; Tate, Alex J.; Martin, Tara J.; Owen, Matthew J.; Tappin, David R.

    2013-09-01

    New multibeam bathymetry data are presented for the South Sandwich intra-oceanic arc which occupies the small Sandwich plate in the South Atlantic, and is widely considered to be a simple end-member in the range of intra-oceanic arc types. The images show for the first time the distribution of submarine volcanic, tectonic and erosional-depositional features along the whole length of the 540 km long volcanic arc, allowing systematic investigation of along-arc variations. The data confirm that the volcanic arc has a simple structure composed of large volcanoes which form a well-defined volcanic front, but with three parallel cross-cutting seamount chains extending 38-60 km from near the volcanic front into the rear-arc. There is no evidence for intra-arc rifting or extinct volcanic lines. Topographic evidence for faulting is generally absent, except near the northern and southern plate boundaries. Most of the volcanic arc appears to be built on ocean crust formed at the associated back-arc spreading centre, as previously proposed from magnetic data, but the southern part of the arc appears to be underlain by older arc or continental crust whose west-facing rifted margin facing the back-arc basin is defined by the new bathymetry. The new survey shows nine main volcanic edifices along the volcanic front and ca. 20 main seamounts. The main volcanoes form largely glaciated islands with summits 3.0-3.5 km above base levels which are 2500-3000 m deep in the north and shallower at 2000-2500 m deep in the south. Some of the component seamounts are interpreted to have been active since the last glacial maximum, and so are approximately contemporaneous with the volcanic front volcanism. Seven calderas, all either submarine or ice-filled, have been identified: Adventure volcano, a newly discovered submarine volcanic front caldera volcano is described for the first time. All but one of the calderas are situated on summits of large volcanoes in the southern part of the arc, and

  13. The Next Generation ARC Middleware and ATLAS Computing Model

    International Nuclear Information System (INIS)

    The distributed NDGF Tier-1 and associated NorduGrid clusters are well integrated into the ATLAS computing environment but follow a slightly different paradigm than other ATLAS resources. The current paradigm does not divide the sites as in the commonly used hierarchical model, but rather treats them as a single storage endpoint and a pool of distributed computing nodes. The next generation ARC middleware with its several new technologies provides new possibilities in development of the ATLAS computing model, such as pilot jobs with pre-cached input files, automatic job migration between the sites, integration of remote sites without connected storage elements, and automatic brokering for jobs with non-standard resource requirements. ARC's data transfer model provides an automatic way for the computing sites to participate in ATLAS’ global task management system without requiring centralised brokering or data transfer services. The powerful API combined with Python and Java bindings can easily be used to build new services for job control and data transfer. Integration of the ARC core into the EMI middleware provides a natural way to implement the new services using the ARC components

  14. Shunting arc plasma source for pure carbon ion beama)

    Science.gov (United States)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  15. Shunting arc plasma source for pure carbon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2012-02-15

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

  16. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse. PMID:22380206

  17. High Voltage Solar Array Arc Testing for a Direct Drive Hall Effect Thruster System

    Science.gov (United States)

    Schneider, Todd; Carruth, M. R., Jr.; Vaughn, J. A.; Jongeward, G. A.; Mikellides, I. G.; Ferguson, D.; Kerslake, T. W.; Peterson, T.; Snyder, D.; Hoskins, A.

    2004-01-01

    The deleterious effects of spacecraft charging are well known, particularly when the charging leads to arc events. The damage that results from arcing can severely reduce system lifetime and even cause critical system failures. On a primary spacecraft system such as a solar array, there is very little tolerance for arcing. Motivated by these concerns, an experimental investigation was undertaken to determine arc thresholds for a high voltage (200-500 V) solar array in a plasma environment. The investigation was in support of a NASA program to develop a Direct Drive Hall-Effect Thruster (D2HET) system. By directly coupling the solar array to a Hall-effect thruster, the D2HET program seeks to reduce mass, cost and complexity commonly associated with the power processing in conventional power systems. In the investigation, multiple solar array technologies and configurations were tested. The cell samples were biased to a negative voltage, with an applied potential difference between them, to imitate possible scenarios in solar array strings that could lead to damaging arcs. The samples were tested in an environment that emulated a low-energy, HET-induced plasma. Short duration trigger arcs as well as long duration sustained arcs were generated. Typical current and voltage waveforms associated with the arc events are presented. Arc thresholds are also defined in terms of voltage, current and power. The data will be used to propose a new, high-voltage (greater than 300 V) solar array design for which the likelihood of damage from arcing is minimal.

  18. 15th Czechoslovak seminar on plasma physics and technology. Part 1

    International Nuclear Information System (INIS)

    Of the 17 papers contained in the proceedings, 8 papers deal with various technological applications of a low-temperature plasma, e.g., the synthesis of very high-purity materials and ultrafine powders, plasma polymerization, and plasma deposition of composite superconducting films. Two papers review the activity in the field of mathematical modeling and experimental investigation of electric arcs used in industrial and laboratory plasmatrons. Other papers report the results of varous diagnostic methods (IR and optical spectroscopy, CARS spectroscopy, probes and interferometry) applied to low-temperature laboratory and technological plasmas. In one paper the positive streamer phenomenon in electric discharges is discussed. (J.U.)

  19. Optical characterization of deposited ITO thin films on glass and PET substrates

    Energy Technology Data Exchange (ETDEWEB)

    Elmas, Saliha; Korkmaz, Şadan, E-mail: skorkmaz@ogu.edu.tr; Pat, Suat

    2013-07-01

    This work focuses on fabrication, characterization and understanding some physical properties of transparent and conductive ITO thin films. ITO thin films were deposited onto glass and polyethylene terephthalate (PET) substrates by thermionic vacuum arc (TVA) technique. TVA is a different technology for thin film deposition. Thicknesses and refractive indices of the ITO thin films have been determined by spectroscopic ellipsometry (SE) technique using Cauchy model for fitting. SE is a novel, nondestructive and powerful technique to investigate the optical characteristics of materials. Especially thickness and optical constants are measuring this device. Transmittances, reflectance of ITO coated samples were measured by UV–vis spectrophotometer and interferometer, respectively. The optical method was used to determine the band gaps of ITO thin films. Surface morphologies of produced films were characterized by atomic force microscope (AFM) for surface topography and roughness of ITO thin films. Resistivity measurements show that produced films show semiconductor properties.

  20. An ARC/INFO point coverage of Mineral Resource Data System (MRDS) locations in eleven western states

    Science.gov (United States)

    Frank, David G.

    1999-01-01

    This ARC/Info coverage, derived from the USGS Mineral Resource Data System (MRDS), contains 60,490 records that fall within the states of Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, Wyoming. The dataset has 13 fields containing information on record identification, location, commodity, geology, and deposit type. The data for this report was retrieved from the master database as a tab text file and imported into a Microsoft Access database. The data was then imported into ESRI’s ArcView where shape files were created. These shape files were then converted into an ARC/INFO coverage.

  1. Small-sized test of gravity separation and preliminary assessment of technology and economics in Guangshigou granite pegmatite type uranium deposit

    International Nuclear Information System (INIS)

    The small-sized test of gravity separation in Guangshigou granite pegmatite type uranium deposit has found a new avenue for the industrial utilization of ores from such uranium deposit, especially those low grade ones. The test has proved that the gravity separation is superior to hydrometallurgy in the aspect of uranium recovery from ores of the granite pegmatite type uranium deposit, by-product recovery and protection against environmental pollution

  2. Development of an annular arc accelerator shock tube driver

    Science.gov (United States)

    Leibowitz, L. P.

    1973-01-01

    An annular arc accelerator (ANAA) shock tube driver has been developed that deposits the energy of an arc discharge into a flowing gas, which then expands and cools without any delay for the opening of a diaphragm. A simplified one-dimensional flow analysis of the ANAA shock tube has been performed, which indicates that shock velocities greater than 40 km/sec may be obtained using a 300-kJ capacitor bank. The ANAA driver consists of a high-pressure driver, an expansion section, and an electrode section. In operation, the cold gas driver is pressurized until the diaphragm bursts, sending a pressure front down the expansion tube to the arc section. When the accelerated flow arrives at the electrode section, a 100-capacitor, 300-kJ capacitor bank is discharged either by breaking an insulating diaphragm between the electrodes or by the triggering of a series of external switches. Shock velocities of 28 km/sec have been obtained, and modifications are described that are expected to improve performance.

  3. ARC length control for plasma welding

    Science.gov (United States)

    Iceland, William F. (Inventor)

    1988-01-01

    A control system to be used with a plasma arc welding apparatus is disclosed. The plasma arc welding apparatus includes a plasma arc power supply, a contactor, and an electrode assembly for moving the electrode relative to a work piece. The electrode assembly is raised or lowered by a drive motor. The present apparatus includes a plasma arc adapter connected across the power supply to measure the voltage across the plasma arc. The plasma arc adapter forms a dc output signal input to a differential amplifier. A second input is defined by an adjustable resistor connected to a dc voltage supply to permit operator control. The differential amplifier forms an output difference signal provided to an adder circuit. The adder circuit then connects with a power amplifier which forms the driving signal for the motor. In addition, the motor connects to a tachometor which forms a feedback signal delivered to the adder to provide damping, therby avoiding servo loop overshoot.

  4. On the formation of auroral arcs

    International Nuclear Information System (INIS)

    A new mechanism for auroral arc formation is presented. The characteristic linear shape of auroral arcs is determined by magnetically connected plasma clouds in the distant equatorial magnetosphere. These clouds originate as high speed plasma beams in the magnetotail and in the solar wind. It is found that the free energy for driving an auroral arc is provided by the difference of pressure between the cloud and the ambient plasma. (author)

  5. Programming ArcGIS with Python cookbook

    CERN Document Server

    Pimpler, Eric

    2015-01-01

    Programming ArcGIS with Python Cookbook, Second Edition, is written for GIS professionals who wish to revolutionize their ArcGIS workflow with Python. Whether you are new to ArcGIS or a seasoned professional, you almost certainly spend time each day performing various geoprocessing tasks. This book will teach you how to use the Python programming language to automate these geoprocessing tasks and make you a more efficient and effective GIS professional.

  6. FASTER MUSE CSP ARC CONSISTENCY ALGORITHMS

    OpenAIRE

    Harper, Mary P.; White, Christopher M.; Helzerman, Randall A.; Hockema, Stephen A.

    1997-01-01

    MUSE CSP (Multiply SEgmented Constraint Satisfaction Problem) [5, 61 is an extension to the constraint satisfaction problem (CSP) which is especially useful for problems that segment into riultiple instances of CSP that share variables. In Belzerman and Harper [6], the concepts of MUSE node, arc, and path consistency were defined and algorithms for MUSE arc consistency, MUSE AC-1, and MUSE path consistency were developed. MUSE AC-1 is similar to the CSP arc consistency algorithm AC-4 [ l j ] ...

  7. The Impact of Teaching Oxy-Fuel Welding on Gas Metal Arc Welding Skills

    Science.gov (United States)

    Sgro, Sergio D.; Field, Dennis W.; Freeman, Steven A.

    2008-01-01

    Industrial technology programs around the country must be sensitive to the demands of manufacturing and industry as they continue to replace "vocational" curriculum with high-tech alternatives. This article examines whether or not teaching oxyacetylene welding in the industrial technology classroom is required to learn arc welding processes. The…

  8. Effect of Gravity on Arc Shape in GTA Welding-for Low Electric Arc Current

    Institute of Scientific and Technical Information of China (English)

    Hidetoshi FUJII; Yosuke SUMI; Manabu TANAKA; Kiyoshi NOGI

    2003-01-01

    Gas tungsten arc (GTA) welding was performed both in a microgravity environment and in a terrestrial environment,and the arc shapes in both environments were compared. A microgravity condition was obtained using the free fallsystem at the Japan Microgravi

  9. Diffuse and spot mode of cathode arc attachments in an atmospheric magnetically rotating argon arc

    International Nuclear Information System (INIS)

    A model including the cathode, near-cathode region, and arc column was constructed. Specifically, a thermal perturbation layer at the arc fringe was calculated in order to couple sheath/presheath modelling with typical arc column modelling. Comparative investigation of two modes of attachment of a dc (100, 150, 200 A) atmospheric-pressure arc in argon to a thermionic cathode made of pure tungsten was conducted. Computational data revealed that there exists two modes of arc discharge: the spot mode, which has an obvious cathode surface temperature peak in the arc attachment centre; and the diffuse mode, which has a flat cathode surface temperature distribution and a larger arc attachment area. The modelling results of the arc attachment agree with previous experimental observations for the diffuse mode. A further 3D simulation is obviously needed to investigate the non-axisymmetrical features, especially for the spot mode. (paper)

  10. The theoretical evaluation of powders transportation in plasma transferred-arc space under coaxial powder feeding condition

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The powders transportation in the plasma transferred-arc space during the coaxial powder-feeding surface depositing process was theoretical evaluated. The axial acceleration and velocity of various particles in the arc column were described. According to the results from theoretical calculations, it was found that: (1) The powder's transporting velocity is much lower than the plasma fluid's; (2) The powders axial transporting velocity presents "valley-shape distribution" along plasma arc column traverse section when surfacing current is greater than 100(¨)A. When the arc current exceeding 100(¨)A, the powders coming through the center field of arc column will transport slower than the powder through the outer-around field of arc column. It is in the field where the temperature is in the range of 9(¨)000(¨)K~11(¨)000(¨)K that the particles can achieve its maximum axial acceleration in the argon plasma space. (3) For the given powder mass density, the smaller its size is, the greater its acceleration and the greater its averaged transporting velocity will be in the arc space; (4) For the given powder size, the greater its mass density is, the smaller its acceleration and averaged velocity will be in the arc space.

  11. Major arcs for Goldbach's problem

    OpenAIRE

    Helfgott, H. A.

    2013-01-01

    The ternary Goldbach conjecture states that every odd number $n\\geq 7$ is the sum of three primes. The estimation of the Fourier series $\\sum_{p\\leq x} e(\\alpha p)$ and related sums has been central to the study of the problem since Hardy and Littlewood (1923). Here we show how to estimate such Fourier series for $\\alpha$ in the so-called major arcs, i.e., for $\\alpha$ close to a rational of small denominator. This is part of the author's proof of the ternary Goldbach conjecture. In contrast ...

  12. Characterization of duplex stainless steel weld metals obtained by hybrid plasma-gas metal arc welding

    Directory of Open Access Journals (Sweden)

    Koray Yurtisik

    2013-09-01

    Full Text Available Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex microstructure without compromising the welding efficiency. 11.1 mm-thick standard duplex stainless steel plates were joined in a single-pass using this novel technique. Same plates were also subjected to conventional gas metal arc and plasma arc welding processes, providing benchmarks for the investigation of the weldability of the material. In the first place, the hybrid welding process enabled us to achieve less heat input compared to gas metal arc welding. Consequently, the precipitation of secondary phases, which are known to be detrimental to the toughness and corrosion resistance of duplex stainless steels, was significantly suppressed in both fusion and heat affected zones. Secondly, contrary to other keyhole techniques, proper cooling time and weld metal chemistry were achieved during the process, facilitating sufficient reconstructive transformation of austenite in the ferrite phase.

  13. Basin formation in the NIAS area of the Sumatra Force Arc, Western Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Milsom, J. (University College, London (United Kingdom))

    1994-07-01

    Although Sumatra includes the site of Indonesia's first oil field and continues to be one of the country's most important hydrocarbon producing regions, the fore-arc basin to the west remains a frontier exploration area. Gas has been found in a number of wells but commercial reserves have yet to be established. The possibility of their existence hinges on the presence of a complex of deep subbasins, but the development of these basins and their relationship to structures onshore Sumatra are still unclear. Although geological observations on the fore-arc islands are acquiring increasing importance with the recognition that the sediments exposed were deposited dominantly or entirely within the fore-arc basin, seismic reflection data remain the key to geological understanding. Reconnaissance surveys in the basin near Nias, the largest of the fore-arc islands, have defined two major depocenters, but interpretation has been hampered by poor data quality in some areas. Measurements of gravity field point to remarkable structural variations along the axis of the fore-arc basin and have been used to amplify and extend seismic interpretation. The combined analysis demonstrates that although some of the structural highs that straddle the fore-arc basin have been positive elements for considerable periods, at least one overlies a deep depression. The very poor quality of the seismic data in parts of the subbasin may be due to extensive shale diapirism, which must be recognized as a factor in future exploration.

  14. Analysis of Fault Arc in High-Speed Switch Applied in Hybrid Circuit Breaker

    Science.gov (United States)

    Wu, Yifei; Ren, Zhigang; Feng, Ying; Li, Mei; Zhang, Hantian

    2016-03-01

    The behavior of fault arc in a high-speed switch (HSS) has been studied theoretically and experimentally. A simplified HSS setup is designed to support this work. A two-dimensional arc model is developed to analyze the characteristics of fault arc based on magnetic-hydrodynamic (MHD) theory. The advantage of such a model is that the thermal transfer coefficient can be determined by depending on the numerical method alone. The influence of net emission coefficients (NEC) radiation model and P1 model on fault arc is analyzed in detail. Results show that NEC model predicts more radiation energy and less pressure rise without the re-absorption effect considered. As a consequence, P1 model is more suitable to calculate the pressure rise caused by fault arc. Finally, the pressure rise during longer arcing time for different arc currents is predicted. supported by National Key Basic Research Program of China (973 Program) (No. 2015CB251001), National Natural Science Foundation of China (Nos. 51221005, 51177124, 51377128, 51323012), the Science and Technology Project Funds of the Grid State Corporation SGSNKYOOKJJS1501564 and Shaanxi Province Natural Science Foundation of China (No. 2013JM-7010)

  15. Orbit Determination Using SLR Data for STSAT-2C: Short-arc Analysis

    Science.gov (United States)

    Kim, Young-Rok; Park, Eunseo; Kucharski, Daniel; Lim, Hyung-Chul

    2015-09-01

    In this study, we present the results of orbit determination (OD) using satellite laser ranging (SLR) data for the Science and Technology Satellite (STSAT)-2C by a short-arc analysis. For SLR data processing, the NASA/GSFC GEODYN II software with one year (2013/04 - 2014/04) of normal point observations is used. As there is only an extremely small quantity of SLR observations of STSAT-2C and they are sparsely distribution, the selection of the arc length and the estimation intervals for the atmospheric drag coefficients and the empirical acceleration parameters was made on an arc-to-arc basis. For orbit quality assessment, the post-fit residuals of each short-arc and orbit overlaps of arcs are investigated. The OD results show that the weighted root mean square post-fit residuals of short-arcs are less than 1 cm, and the average 1-day orbit overlaps are superior to 50/600/900 m for the radial/cross-track/along-track components. These results demonstrate that OD for STSAT-2C was successfully achieved with cm-level range precision. However its orbit quality did not reach the same level due to the availability of few and sparse measurement conditions. From a mission analysis viewpoint, obtaining the results of OD for STSAT-2C is significant for generating enhanced orbit predictions for more frequent tracking.

  16. Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

    2011-06-01

    Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

  17. Metals purification by improved vacuum arc remelting

    Science.gov (United States)

    Zanner, Frank J.; Williamson, Rodney L.; Smith, Mark F.

    1994-12-13

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  18. Electrode Evaporation Effects on Air Arc Behavior

    Institute of Scientific and Technical Information of China (English)

    LI Xingwen; CHEN Degui; LI Rui; WU Yi; NIU Chunping

    2008-01-01

    A numerical study of the effects of copper and silver vapours on the air arc behavior is performed. The commercial software FLUENT is adapted and modified to develop a two-dimensional magneto-hydrodynamic (MHD) models of arc with the thermodynamic properties and transport coefficients, net emission coefficient for the radiation model of 99% ai-1% Cu, 99% air-1% Ag, and pure air, respectively. The simulation result demonstrates that vaporization of the electrode material may cool the arc center region and reduce the arc velocity. The effects of Ag vapour are stronger compared to those of Cu vapour.

  19. The Abundance of Large Arcs From CLASH

    Science.gov (United States)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Coe, Dan A.; Clash Team

    2015-01-01

    We have developed an automated arc-finding algorithm to perform a rigorous comparison of the observed and simulated abundance of large lensed background galaxies (a.k.a arcs). We use images from the CLASH program to derive our observed arc abundance. Simulated CLASH images are created by performing ray tracing through mock clusters generated by the N-body simulation calibrated tool -- MOKA, and N-body/hydrodynamic simulations -- MUSIC, over the same mass and redshift range as the CLASH X-ray selected sample. We derive a lensing efficiency of 15 ± 3 arcs per cluster for the X-ray selected CLASH sample and 4 ± 2 arcs per cluster for the simulated sample. The marginally significant difference (3.0 σ) between the results for the observations and the simulations can be explained by the systematically smaller area with magnification larger than 3 (by a factor of ˜4) in both MOKA and MUSIC mass models relative to those derived from the CLASH data. Accounting for this difference brings the observed and simulated arc statistics into full agreement. We find that the source redshift distribution does not have big impact on the arc abundance but the arc abundance is very sensitive to the concentration of the dark matter halos. Our results suggest that the solution to the "arc statistics problem" lies primarily in matching the cluster dark matter distribution.

  20. Performance tracking under ARCS contracts. Directive

    International Nuclear Information System (INIS)

    The directive discusses the development of a non-resource intensive method for reporting performance based work allocation results under the ARCS (Alternative Remedial Contracting Strategy) contractors

  1. Generalized hyperfocused arcs in $PG(2,p)$

    OpenAIRE

    Blokhuis, A Aart; Marino, G.; Mazzocca, F.

    2013-01-01

    A {\\em generalized hyperfocused arc} $\\mathcal H $ in $PG(2,q)$ is an arc of size $k$ with the property that the $k(k-1)/2$ secants can be blocked by a set of $k-1$ points not belonging to the arc. We show that if $q$ is a prime and $\\mathcal H$ is a generalized hyperfocused arc of size $k$, then $k=1,2$ or 4. Interestingly, this problem is also related to the (strong) cylinder conjecture [Ball S.: The polynomial method in Galois geometries, in Current research topics in Galois geometry, Chap...

  2. Micro-arcing and arc erosion minimization using a DC hybrid switching device

    OpenAIRE

    Swingler, J.; McBride, J. W.

    2008-01-01

    Hybrid switching devices utilize the advantages of both conventional electrical contacts and solid state electronics to minimize arcing during opening and closing operations. This can result in higher reliability and reduces the need for high cost specialist contact materials. The hybrid switch does not eliminate arcing completely, due to the inductive nature of circuits; micro-arcing is known to occur. An experimental dc hybrid switching device is introduced which minimizes arcing for 42 ...

  3. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  4. 热电偶测温技术在埋弧焊温度场测量中的应用%Application of Thermocouple Technology in Temperature Field Measurement of Submerged Arc Welding

    Institute of Scientific and Technical Information of China (English)

    赵波; 杨玮玮; 张红; 胡海朝; 杨新岐; 陈小伟; 李志华; 李国鹏

    2012-01-01

    介绍了一种直缝埋弧焊管焊接热循环参数测量的方法,设计了背面打孔的热电偶测温方案,成功实现了直缝埋弧焊管焊缝热影响区各个分区的焊接热循环曲线测量,解决了埋弧焊热循环参数准确测量的难题,可为焊接温度场数值模拟计算提供实测数据,为焊接工艺参数的制定和优化、焊缝及热影响区组织性能改善提供了重要的依据,对于提高埋弧焊管焊缝质量具有重要意义.%A method used to measure the parameters of welding thermal cycle for SAWL pipe was introduced in this paper. The temperature measuring scheme using a thermocouple punched on the back surface was designed, which successfully realized the measurement of curves for welding thermal cycles of various subzones in HAZ of SAWL pipe, solved the problem of accurate measurement of thermal cycle parameters for SAW (submerged-arc welding). This method can provide actual measurement data for welding temperature field numerical simulation, and supply important basis for establishment and optimization of the welding process parameters, improvement of the microstructure properties in weld and HAZ. Thus it plays and important role in increasing the weld quality of SAW pipe.

  5. Advanced Gas Tungsten Arc Weld Surfacing Current Status and Application

    Directory of Open Access Journals (Sweden)

    Stephan Egerland

    2015-09-01

    Full Text Available Abstract Gas Shielded Tungsten Arc Welding (GTAW – a process well-known providing highest quality weld results joined though by lower performance. Gas Metal Arc Welding (GMAW is frequently chosen to increase productivity along with broadly accepted quality. Those industry segments, especially required to produce high quality corrosion resistant weld surfacing e.g. applying nickel base filler materials, are regularly in consistent demand to comply with "zero defect" criteria. In this conjunction weld performance limitations are overcome employing advanced 'hot-wire' GTAW systems. This paper, from a Welding Automation perspective, describes the technology of such devices and deals with the current status is this field – namely the application of dual-cathode hot-wire electrode GTAW cladding; considerably broadening achievable limits.

  6. Tectonic, magmatic, and metallogenic evolution of the Late Cretaceous arc in the Carpathian-Balkan orogen

    Science.gov (United States)

    Gallhofer, Daniela; Quadt, Albrecht von; Peytcheva, Irena; Schmid, Stefan M.; Heinrich, Christoph A.

    2015-09-01

    The Apuseni-Banat-Timok-Srednogorie Late Cretaceous magmatic arc in the Carpathian-Balkan orogen formed on the European margin during closure of the Neotethys Ocean. It was subsequently deformed into a complex orocline by continental collisions. The Cu-Au mineralized arc consists of geologically distinct segments: the Apuseni, Banat, Timok, Panagyurishte, and Eastern Srednogorie segments. New U-Pb zircon ages and geochemical whole rock data for the Banat and Apuseni segments are combined with previously published data to reconstruct the original arc geometry and better constrain its tectonic evolution. Trace element and isotopic signatures of the arc magmas indicate a subduction-enriched source in all segments and variable contamination by continental crust. The magmatic arc was active for 25 Myr (~92-67 Ma). Across-arc age trends of progressively younger ages toward the inferred paleo-trench indicate gradual steepening of the subducting slab away from the upper plate European margin. This leads to asthenospheric corner flow in the overriding plate, which is recorded by decreasing 87Sr/86Sr (0.70577 to 0.70373) and increasing 143Nd/144Nd (0.51234 to 0.51264) ratios over time in some segments. The close spatial relationship between arc magmatism, large-scale shear zones, and related strike-slip sedimentary basins in the Timok and Pangyurishte segments indicates mild transtension in these central segments of the restored arc. In contrast, the Eastern Srednogorie segment underwent strong orthogonal intraarc extension. Segmental distribution of tectonic stress may account for the concentration of rich porphyry Cu deposits in the transtensional segments, where lower crustal magma storage and fractionation favored the evolution of volatile-rich magmas.

  7. LDRD Final Report - Investigations of the impact of the process integration of deposited magnetic films for magnetic memory technologies on radiation hardened CMOS devices and circuits - LDRD Project (FY99)

    International Nuclear Information System (INIS)

    This project represented a coordinated LLNL-SNL collaboration to investigate the feasibility of developing radiation-hardened magnetic non-volatile memories using giant magnetoresistance (GMR) materials. The intent of this limited-duration study was to investigate whether giant magnetoresistance (GMR) materials similar to those used for magnetic tunnel junctions (MTJs) were process compatible with functioning CMOS circuits. Sandia's work on this project demonstrated that deposition of GMR materials did not affect the operation nor the radiation hardness of Sandia's rad-hard CMOS technology, nor did the integration of GMR materials and exposure to ionizing radiation affect the magnetic properties of the GMR films. Thus, following deposition of GMR films on rad-hard integrated circuits, both the circuits and the films survived ionizing radiation levels consistent with DOE mission requirements. Furthermore, Sandia developed techniques to pattern deposited GMR films without degrading the completed integrated circuits upon which they were deposited. The present feasibility study demonstrated all the necessary processing elements to allow fabrication of the non-volatile memory elements onto an existing CMOS chip, and even allow the use of embedded (on-chip) non-volatile memories for system-on-a-chip applications, even in demanding radiation environments. However, funding agencies DTRA, AIM, and DARPA did not have any funds available to support the required follow-on technology development projects that would have been required to develop functioning prototype circuits, nor were such funds available from LDRD nor from other DOE program funds

  8. Computational study of flow dynamics from a dc arc plasma jet

    CERN Document Server

    Trelles, Juan Pablo

    2013-01-01

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviat...

  9. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2011-12-18

    Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

  10. ARC SDK: A toolbox for distributed computing and data applications

    International Nuclear Information System (INIS)

    Grid middleware suites provide tools to perform the basic tasks of job submission and retrieval and data access, however these tools tend to be low-level, operating on individual jobs or files and lacking in higher-level concepts. User communities therefore generally develop their own application-layer software catering to their specific communities' needs on top of the Grid middleware. It is thus important for the Grid middleware to provide a friendly, well documented and simple to use interface for the applications to build upon. The Advanced Resource Connector (ARC), developed by NorduGrid, provides a Software Development Kit (SDK) which enables applications to use the middleware for job and data management. This paper presents the architecture and functionality of the ARC SDK along with an example graphical application developed with the SDK. The SDK consists of a set of libraries accessible through Application Programming Interfaces (API) in several languages. It contains extensive documentation and example code and is available on multiple platforms. The libraries provide generic interfaces and rely on plugins to support a given technology or protocol and this modular design makes it easy to add a new plugin if the application requires supporting additional technologies.The ARC Graphical Clients package is a graphical user interface built on top of the ARC SDK and the Qt toolkit and it is presented here as a fully functional example of an application. It provides a graphical interface to enable job submission and management at the click of a button, and allows data on any Grid storage system to be manipulated using a visual file system hierarchy, as if it were a regular file system.

  11. Tectonic and sedimentary evolution of a Cretaceous continental arc-backarc system in the Korean peninsula: New view

    Science.gov (United States)

    Chough, S. K.; Sohn, Y. K.

    2010-08-01

    This paper focuses on the tectonic and sedimentary evolution of the Cretaceous volcanic rocks and nonmarine successions in the southeastern part of the Korean peninsula, which constitute an ancient continental arc system. The arc system (Gyeongsang Arc System), comprising an arc platform (Gyeongsang Volcanic Arc) and a backarc basin (Gyeongsang Backarc Basin), was a southwestward extension of the Japanese Arc formed by oblique northward subduction of the proto-Pacific (Izanagi) plate under the Asian continent. The backarc basin was initiated in the southeastern part of the Korean peninsula in the Early Cretaceous as a narrow NS-trending trough. The basin was bounded by a major fault in the northern part of the basin from which sediments largely emanated. Sediments were deposited in streamflow-dominated alluvial fans adjacent to the fault-bounded basin margin in the north and low-gradient fluvial systems of braided channels that extended southward and southeastward for tens of kilometers. Sediments were also derived from the western highland margin, draining Precambrian to Jurassic basement rocks. The initially narrow trough progressively expanded toward the east, resulting in eastward migration of depocenters that eventually generated a broad fluvio-lacustrine plain fringing the volcanic arc platform. The arc platform played an important role for the derivation of volcanogenic materials and accreted sediments into the backarc basin via extensive fluvial network. Pyroclastic density currents and landslides, which originated from the arc platform, also entered the basin. In addition, extrusion of basaltic volcanic rocks was continual within the basin during basin expansion. The resultant succession of mixed sedimentary and volcanogenic rocks is generally indicative of a temporal increase in volcanic activity in the arc platform and in subsidence rate of the basin. In the Late Cretaceous, andesitic to rhyolitic volcanism became climactic in the arc platform, producing

  12. Electroless nickel plating of arc discharge synthesized carbon nanotubes for metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Jagannatham, M.; Sankaran, S.; Prathap, Haridoss, E-mail: prathap@iitm.ac.in

    2015-01-01

    Highlights: • Electroless Ni coatings have been performed on CNTs for various deposition times. • The deposition of nickel increased with increase in deposition time. • A deposition time of 60 min has been optimum for uniform coating of Ni on CNTs. • The CNTs with uniform coating of Ni are potential for reinforcements in composites. • Electroless nickel coatings are determined to be super paramagnetic behavior. - Abstract: Electroless nickel (EN) plating was performed on arc discharge synthesized multiwalled carbon nanotubes for various deposition times. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Raman spectroscopy characterization techniques are used to identify the presence of nickel deposition on the carbon nanotubes (CNTs) and the degree of graphitization. The results indicate that impurities are less in the purified CNTs as compared to raw carbon soot. Increasing deposition time up to 60 min increases uniform deposition of nickel throughout the length of the CNTs. However, for deposition time longer than 60 min, nickel particles are seen separated from the surface of the CNTs. Uniformly coated nickel CNTs throughout their length are potential candidates for reinforcements in composite materials. Magnetic properties of the nickel coated CNTs, with deposition time of 30 and 60 min were also evaluated. The magnetic saturation of nickel coated CNTs with deposition time of 30 min is less compared to nickel coated CNTs with deposition time of 60 min.

  13. Chapter 4. Uranium extraction technology from wastes of uranium industry. 4.1. Sulfuric acid leaching kinetics of residues from anthropogenic deposit Map 1-9

    International Nuclear Information System (INIS)

    Present article is devoted to sulfuric acid leaching kinetics of residues from anthropogenic deposit Map 1-9. Since residues from anthropogenic deposit Map 1-9 basically contain quartz (69%), it went through acid leaching. Results of laboratory investigations on the opening degree and uranium conversion to solution were summarized. The influence of sulfuric acid consumption on uranium extraction during leaching (U = 0,018%, t =20 deg C, t = 10 hours) was considered. The kinetic and energetic parameters of residues leaching of anthropogenic deposit Map 1-9 was discussed. The basic process flow diagram of uranium industry wastes reprocessing was proposed.

  14. Municipal solid waste disposal by using metallurgical technologies and equipments

    OpenAIRE

    Jiuju Cai, Wenqiang Sun

    2012-01-01

    Pyrolysis of municipal solid waste can take full advantage of energy and resource and avoid producing hazardous material during this period. In combination with mature metallurgical technologies of coking by coke oven, regenerative flame furnace technology and melting by electric arc furnace, technologies of regenerative fixed bed pyrolysis technology for household waste, co-coking technology for waste plastic and blend coal, and incineration ash melting technology by electric arc technology ...

  15. The structure and singularities of arc complexes

    DEFF Research Database (Denmark)

    Penner, Robert

    A classical combinatorial fact is that the simplicial complex consisting of disjointly embedded chords in a convex planar polygon is a sphere. For any surface F with non-empty boundary, there is an analogous complex Arc(F) consisting of suitable equivalence classes of arcs in F connecting its bou...

  16. Risk assessment of metal vapor arcing

    Science.gov (United States)

    Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

    2009-01-01

    A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

  17. Characterization of Micro-arc Oxidized Titanium

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro-arc oxidized titanium was evaluated by human body derived osteoblasts and slightly better than those of blasted surface.

  18. 钢轨自保护药芯焊丝自动窄间隙电弧焊工艺及装备研究%Technology and equipment development of self-shielded flux cored narrow gap arc rail welding

    Institute of Scientific and Technical Information of China (English)

    宋宏图; 李力; 丁韦; 季关钰

    2011-01-01

    无缝线路建设的大范围展开迫切需要性能、质量、生产效率相匹配的原位焊接方法,目前使用最多的为铝热焊和电弧焊.介绍了窄间陈电弧焊在钢轨焊接中的应用,并重点对电弧位置实时检测技术和自保护药芯焊丝自动钢轨窄间隙电弧焊工艺及装备进行了说明.进行接头性能试验,结果表明:采用钢轨自保护药芯焊丝自动窄间隙电弧焊焊接的接头性能良好,完全超过另外一种原位焊接方法铝热焊的接头性能,能够通过铝热焊不能通过的落锤试验,拉伸性能也强于铝热焊,冲击性能大幅度优于目前使用的闪光焊、气压焊和铝热焊.%Higher joint quality and performance good production efficiency in situ rail welding method should be developed for jointless railway wide construction. Nowadays most ways in used are thermit welding and arc welding. In this paper,narrow gap are welding used in rail welding is introduced,especially on our study of automatic narrow gap are rail welding using self-shielded flux cored wire and based on are position vision detection.Joint properties is overall better than another method thermit welding of in situ welding joint performance,can pass through the drop hammer test,tensile properties is also stronger than thermit welding,the impact performance significantly better than the currently used flash welding, gas pressure welding and thermit welding.

  19. Do technological advances in linear accelerators improve dosimetric outcomes in stereotaxy? A head-on comparison of seven linear accelerators using volumetric modulated arc therapy-based stereotactic planning

    Directory of Open Access Journals (Sweden)

    B Sarkar

    2016-01-01

    Full Text Available Introduction: Linear accelerator (Linac based stereotactic radiosurgery (SRS and stereotactic radiotherapy (SRT using volumetric modulated arc therapy (VMAT has been used for treating small intracranial lesions. Recent development in the Linacs such as inbuilt micro multileaf collimator (MLC and flattening filter free (FFF beam are intended to provide a better dose conformity and faster delivery when using VMAT technique. This study was aimed to compare the dosimetric outcomes and monitor units (MUs of the stereotactic treatment plans for different commercially available MLC models and beam profiles. Materials and Methods: Ten patients having 12 planning target volume (PTV/gross target volume's (GTVs who received the SRS/SRT treatment in our clinic using Axesse Linac (considered reference arm gold standard were considered for this study. The test arms comprised of plans using Elekta Agility with FFF, Elekta Agility with the plane beam, Elekta APEX, Varian Millennium 120, Varian Millennium 120HD, and Elekta Synergy in Monaco treatment planning system. Planning constraints and calculation grid spacing were not altered in the test plans. To objectively evaluate the efficacy of MLC-beam model, the resultant dosimetric outcomes were subtracted from the reference arm parameters. Results: V95%, V100%, V105%, D1%, maximum dose, and mean dose of PTV/GTV showed a maximum inter MLC - beam model variation of 1.5% and 2% for PTV and GTV, respectively. Average PTV conformity index and heterogeneity index shows a variation in the range 0.56–0.63 and 1.08–1.11, respectively. Mean dose difference (excluding Axesse for all organs varied between 1.1 cGy and 74.8 cGy (mean dose = 6.1 cGy standard deviation [SD] = 26.9 cGy and 1.7 cGy–194.5 cGy (mean dose 16.1 cGy SD = 57.2 cGy for single and multiple fraction, respectively. Conclusion: The dosimetry of VMAT-based SRS/SRT treatment plan had minimal dependence on MLC and beam model variations. All tested MLC

  20. 利用垃圾焚烧飞灰电弧炉熔渣制备微晶玻璃%PRODUCTION OF GLASS-CERAMICS FROM INCINERATION FLY ASH BY USING ELECTRONIC ARC FURNACE TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    魏国侠; 刘汉桥

    2011-01-01

    垃圾焚烧飞灰电弧炉熔渣经核化、晶化两步处理制备微晶玻璃,采用差热分析法研究了基础玻璃的晶化行为,考察了晶化时间对微晶玻璃微观结构及理化特性的影响。结果表明:基础玻璃的晶化指数为1.48,以表面析晶为主,其最佳热处理制度为:核化温度679℃、核化时间1.5h、晶化温度985℃、晶化时间1.5h。微晶玻璃的主晶相为透辉石Ca(Mg,Al)(Si,Al)_2O_6和少量普通辉石Ca(Mg,Fe,Al)-(Si,Al)_2O_6,在最佳热处理条件下制得的微晶玻璃具有较高的抗弯强度、硬度、韧性及耐酸碱性等性能,有替代天然建材的潜力。%Glass-ceramics by nucleating and crystallization of the molten slag obtained from incinerator fly ash using electric arc furnace treatment was produced.The crystallization behaviour of parent glass was examined on the basis of differential thermal analysis(DTA) results.The effects of crystallization time on the microstructure and the properties of glass-ceramics were studied.The experimental results showed that Avrami exponent for parent glass is 1.48 which indicated that the surface crystallization is dominant during crystallization.The optimum heat-treatment schedule for parent glass is nucleating at 679℃for 1.5 h and crystallizing at 985℃for 1.5h.The main crystalline phase of the glass-ceramics is diopside(Ca(Mg,Al)(Si,Al)_2O_6) and small amount of augite Ca(Mg,Fe,Al)(Si,Al)_2O_6.Glass-ceramics produced at an optimum heat treatment condition showed sufficiently high bending strength,hardness,fracture toughness and chemical resistance to be used in building materials requiring good mechanical and chemical properties.

  1. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    International Nuclear Information System (INIS)

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  2. Sensor Control of Robot Arc Welding

    Science.gov (United States)

    Sias, F. R., Jr.

    1983-01-01

    The potential for using computer vision as sensory feedback for robot gas-tungsten arc welding is investigated. The basic parameters that must be controlled while directing the movement of an arc welding torch are defined. The actions of a human welder are examined to aid in determining the sensory information that would permit a robot to make reproducible high strength welds. Special constraints imposed by both robot hardware and software are considered. Several sensory modalities that would potentially improve weld quality are examined. Special emphasis is directed to the use of computer vision for controlling gas-tungsten arc welding. Vendors of available automated seam tracking arc welding systems and of computer vision systems are surveyed. An assessment is made of the state of the art and the problems that must be solved in order to apply computer vision to robot controlled arc welding on the Space Shuttle Main Engine.

  3. Depending on scientific and technological progress to prospect for superlarge uranium deposits. Across-century target for uranium resources exploration work in China

    International Nuclear Information System (INIS)

    After over 30 years' development, uranium resources exploration work in China has resulted in the discovery of more than 10 economic types of uranium deposits in 23 provinces (regions) of the whole country and large quantities of uranium reserves have been submitted which guarantee the development of nuclear industry in China. However, characteristics such as smaller size of deposits and ore bodies, and lower ore grade of discovered China's uranium deposits have brought about a series of problems on how to economically exploit and utilize these uranium resources. To prospect for superlarge uranium deposits is a guarantee of making uranium resources essentially meet the demand for the long-term development of nuclear industry in China, and is an important way of improving economic benefits in mining China's uranium resources. It is an important mark for uranium geological exploration work to go up a new step as well. China exhibits the geological environment in which various types of superlarge uranium deposits can be formed. Having the financial support from the state to uranium resources exploration work, having professional uranium exploration teams well-experienced in ore prospecting, having modernized uranium exploration techniques and equipment and also having foreign experience in prospecting for superlarge uranium deposits as reference, it is entirely possible to find out superlarge uranium deposits in China at the end of this century and at the beginning of next century. In order to realize the objective, the most important prerequisite is that research work on metallogenetic geological theory and exploration techniques and prospecting methodology for superlarge uranium deposits must be strengthened, and technical quality of the geological teams must be improved. Within this century, prospect targets should be selected and located accurately to carry out the emphatic breakthrough in exploration strategy

  4. Deposition and optimization of thin lead layers for superconducting accelerator photocathodes

    CERN Document Server

    Lorkiewicz, J; Barlak, M; Mirowski, R; Bartnik, A; Kostecki, J; Sekutowicz, J; Malinowska, A; Kneisel, P; Witkowski, J

    2014-01-01

    A combination of a ultra high vacuum arc deposition system and a recrystallization method was used to optimize the smoothness and thickness of thin-layer lead cathodes for superconducting niobium electron injectors. A non-filtered arc system was chosen to deposit Pb films on niobium. The films then underwent melting and recrystallization by treating them with pulsed argon ion beams in a rod plasma injector.

  5. Role of arc mode in laser-metal active gas arc hybrid welding of mild steel

    International Nuclear Information System (INIS)

    Highlights: • Pulsed arc is more effective to improve the stability of laser-arc hybrid welding. • LCHW has the highest fraction of acicular ferrite and high-angle grain boundaries. • Grain refinement depends on effective current of the arc. • LSHW has the most apparent vestige of texture components. • The microstructure and microtexture formation mechanisms were summarized. - Abstract: Arc mode plays an important role in joint characterizations of arc welding, but it has been seldom considered in laser-arc hybrid welding. This paper investigated the role of arc mode on laser-metal active gas (MAG) arc hybrid welding of mild steel. Three arc modes were employed, which were cold metal transfer (CMT), pulsed spray arc and standard short circuiting arc. Microtexture of the joints were observed and measured via electron back scattering diffraction (EBSD) system to reveal the effect of arc mode on microstructure. Mechanical properties of the joints were evaluated by tensile and Charpy V-notch impact tests. It was found that both the stability and mechanical properties of laser-CMT hybrid welding (LCHW) is the best, while those of laser-standard short circuiting arc welding (LSHW) is the worst. OM and EBSD results showed that the fraction of acicular ferrite and high-angle grain boundaries in fusion zone decreases gradually in the sequence of LCHW, laser-pulsed spray arc welding and LSHW, while the mean grain size increases gradually. Finally, the microstructure formation mechanisms and the relationship between microstructure and mechanical properties were summarized by the loss of alloying element and the stirring effect in molten pool

  6. INTERPOLATION WITH RESTRICTED ARC LENGTH

    Institute of Scientific and Technical Information of China (English)

    Petar Petrov

    2003-01-01

    For given data (ti,yi), I= 0,1,…,n,0 = t0 <t1 <…<tn = 1we study constrained interpolation problem of Favard type inf{‖f"‖∞|f∈W2∞[0,1],f(ti)=yi,i=0,…,n,l(f;[0,1])≤l0}, wherel(f";[0,1])=∫1 0 / 1+f'2(x)dx is the arc length off in [0,1]. We prove the existence of a solution f* of the above problem, that is a quadratic spline with a second derivative f"* , which coincides with one of the constants - ‖f"*‖∞,0,‖f"*‖∞ between every two consecutive knots. Thus, we extend a result ofKarlin concerning Favard problem, to the case of restricted length interpolation.

  7. Evaluation of the clinical usefulness of modulated Arc treatment

    OpenAIRE

    Lee, Young Kyu; Jang, Hong Seok; Kim, Yeon Sil; Choi, Byung Ock; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; PARK, SUNG KWANG; Kim, Jin Young; Kang, Young-Nam

    2015-01-01

    The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans of the non-small cell lung cancer (NSCLC) patients were performed in order to verify the clinical usefulness of mARC. A pre study was conducted to find the most competent plan condition of mARC treatment and the usefulness of mARC treatment plan was evaluated by comparing it with the other Arc treatment plans such as Tomotherapy and RapidArc. In the case of m...

  8. Seismic Reflection Image Across the Izu-Bonin Island Arc System

    Science.gov (United States)

    Park, J.; Tsuru, T.; Takahashi, N.; Kodaira, S.; Kaneda, Y.

    2002-12-01

    The Izu-Bonin island arc system occupies almost a northern half of the Izu-Bonin-Island (IBM) arc system extending 2500 km south from near Tokyo, which is one of the largest convergent margins on earth. This Izu-Bonin island arc system is a typical intra-oceanic island arc system involving trench-arc-backarc basin system, i.e., the Izu-Bonin trench, the Izu-Bonin arc, and the backarc Shikoku basin. In order to figure out the past 50 m.y. development history of the entire Izu-Bonin intra-oceanic island arc system, we collected marine multichannel seismic (MCS) reflection data across the island arc system on board the R/V Kairei of the Japan Marine Science and Technology Center (JAMSTEC) in May 2002. We used a ~5-km, 204-channel streamer and a 12,000 cubic inch (~200 L) air-guns array. Receiver spacing was 25-m, yielding 51-fold coverage at 12.5-m CDP spacing. We acquired the MCS data on two different lines: ~560-km-long Line 1 and ~1140-km-long Line 3. The MCS data were migrated in depth domain. Velocity-depth models for the depth migration were iteratively constructed by prestack depth migration velocity analysis. Wide-angle data guided the velocity analysis. In this paper, we show the two MCS profiles and discuss the development process of the Izu-Bonin island arc system from viewpoints of seismic stratigraphy and structure. We identify a clear seismic reflector of the subducting Pacific plate with several horst-and-graben structures, which can be observed beneath the arc more than 60 km landward from the trench axis. Forearc basin is characterized by several buried normal faults and vigorous intra-oceanic sedimentation. In the arc rifting zone, we observe many seismic hyperbolic signatures indicative of active volcanic intrusions, which are related to active magmatism. The topmost sedimentary cover sequences are obviously tilted and cut by many normal faults. It is noticeable that reflectors of the middle crust in the arc-backarc transition zone appear to pinch

  9. Liquefier Dynamics in Fused Deposition

    DEFF Research Database (Denmark)

    Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio

    2004-01-01

    Layered manufacturing (LM) is an evolution of rapid prototyping (RP) technology whereby a part is built in layers. Fused deposition modeling (FDM) is a particular LM technique in which each section is fabricated through vector style deposition of building blocks, called roads, which are then...

  10. Propagation of back-arc extension into the arc lithosphere in the southern New Hebrides volcanic arc

    Science.gov (United States)

    Patriat, M.; Collot, J.; Danyushevsky, L.; Fabre, M.; Meffre, S.; Falloon, T.; Rouillard, P.; Pelletier, B.; Roach, M.; Fournier, M.

    2015-09-01

    New geophysical data acquired during three expeditions of the R/V Southern Surveyor in the southern part of the North Fiji Basin allow us to characterize the deformation of the upper plate at the southern termination of the New Hebrides subduction zone, where it bends eastward along the Hunter Ridge. Unlike the northern end of the Tonga subduction zone, on the other side of the North Fiji Basin, the 90° bend does not correspond to the transition from a subduction zone to a transform fault, but it is due to the progressive retreat of the New Hebrides trench. The subduction trench retreat is accommodated in the upper plate by the migration toward the southwest of the New Hebrides arc and toward the south of the Hunter Ridge, so that the direction of convergence remains everywhere orthogonal to the trench. In the back-arc domain, the active deformation is characterized by propagation of the back-arc spreading ridge into the Hunter volcanic arc. The N-S spreading axis propagates southward and penetrates in the arc, where it connects to a sinistral strike-slip zone via an oblique rift. The collision of the Loyalty Ridge with the New Hebrides arc, less than two million years ago, likely initiated this deformation pattern and the fragmentation of the upper plate. In this particular geodynamic setting, with an oceanic lithosphere subducting beneath a highly sheared volcanic arc, a wide range of primitive subduction-related magmas has been produced including adakites, island arc tholeiites, back-arc basin basalts, and medium-K subduction-related lavas.

  11. Pulmón del soldador de arco Arc welder's lung

    Directory of Open Access Journals (Sweden)

    Luciana Molinari

    2010-12-01

    Full Text Available La siderosis del soldador o neumoconiosis siderótica fue descripta por Doig y McLaughlin en 1936 como una enfermedad pulmonar causada por la inhalación crónica de polvo de hierro en soldadores de arco eléctrico. Presentamos un caso de siderosis del soldador asociada a aumento de los niveles de ferritina, sin hallazgo de depósito de hierro en otros órganos y sin causas evidentes de hemosiderosis secundaria.Pneumoconiosis of electric arc welder or siderotic pneumoconiosis was described by Doig and McLaughlin in 1936 as a lung disease caused by chronic inhalation of iron fumes in electric arc welders. We present a case report of electric arc welder siderosis associated with high levels of ferritin, without findings of iron deposit in any other organ.

  12. Petrologic Evolution of Palau; A Nascent Island Arc

    Science.gov (United States)

    Hawkins, J. W.; Ishizuka, O.

    2008-12-01

    Initiation of subduction in intra-oceanic settings requires relative differences in plate thickness and density (i.e., age difference); a major zone of weakness separating the plates, e.g., a fracture zone; and a change in relative vectors of movement to cause convergence. These factors help explain the origin of the southern- most part of the > 2500 km long Kyushu - Palau Ridge (KPR). Palau Islands, at 7 deg 30 ' N, are the only significant emergent feature on KPR. Small islands are mainly uplifted Pliocene and younger reef carbonate. Large islands are mainly volcanic comprising rare boninite; major basalt, basaltic andesite and andesite; and minor dacite. Polymict breccia is abundant; sills, flows, dikes are common; pillows are rare. The same rock types, as well as high-Mg basalt, were dredged from the Palau Trench. Volcanism on Palau began in late Eocene and ended by early Miocene. Rocks are low-K primitive island arc- tholeiite series. None are MORB. REE and HFSE require a depleted mantle source. Zr* and Ti* suggest that melts interacted with OL-PX rocks of upper mantle or deep crust cumulates. Moderate enrichment of LILE and LREE indicate influx of "dehydration fluid." Ce/Ce* and Eu/Eu* show no evidence for subducted sediments or recycling of arc- derived clastics yet there is no accreted sedimentary prism. This paradox may be owing to lack of arc or terrigenous clastics on seafloor formed in open ocean "sterile" equatorial latitudes. Plate reconstructions and paleomagnetic data suggest that the "arc" probably formed on the trace of a transform fault that has migrated northward and rotated clockwise up to 90 deg. since Oligocene time. Episodes of transtension allowed upwelling of relatively fertile hot mantle into depleted mantle and sheared, altered, rocks of the transform. Episodes of transpression may have initiated subduction of seafloor having a thin cover of pelagic sediments (calcareous and radiolarian ooze, chert, chalk, limestone) deposited far from

  13. Cathodic micro-arc electrodeposition of yttrium stabilized zirconia (YSZ) coatings on FeCrAl alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The formation of ceramic coatings on metal substrate by cathodic electrolytic deposition (CELD) has received more attention in recent years. But only thin films can be prepared via CELD. Yttrium stabilized zirconia (YSZ) ceramic coatings were deposited on FeCrAl alloy by a novel technique--cathodic micro-arc electrodeposition (CMED). The result shows that, when a high pulse electric field is applied to the cathode which was pre-deposited with a thin YSZ film, dielectric breakdown occurs and micro-arc discharges appear. Coatings with reasonably thickness of ~300μm and crystalline structure can be deposited on the cathode by utilizing the energy of the micro-arc. The thickness of the as-deposited coating is dominated by the voltage and the frequency. Y2O3 is co-deposited with ZrO2 when Y(NO3)3 was added to the electrolyte, which stabilize t-phase, t′- phase and c-phase of ZrO2 at room temperature. The amount of the m-ZrO2 in the coating is diminished by increasing the concentration of Y(NO3)3 in the electrolyte. This report describes the processing of CMED and studies the microstructure of the deposited YSZ coatings.

  14. Seismic stratigraphy of barrier-island arc retreat paths in Mississippi River delta

    Energy Technology Data Exchange (ETDEWEB)

    Penland, S.; Suter, J.R.

    1983-09-01

    The stratigraphic record preserved in the retreat path of Mississippi delta barrier-island arcs is controlled by erosional shoreface retreat processes, relative sea level rise, and sediment supply. More than 500 km (300 mi) of high resolution shallow seismic profiles correlated with vibracores from retreat paths fronting the Isles Dernieres and Chandeleur barrier-island arcs, show contrasting stratigraphic sequences preserved on the inner continental shelf (Mississippian delta). The Isles Dernieres barrier-island arc developed as a consequence of the Caillou Headland abandonment in the early Lafourche delta approximately 800 years B.P. On the lower shoreface, channels can be seen projecting seaward under the central part of the island arc; associated with it is a beach-ridge plain extending eastward. On the inner shelf, a sand sheet up to 60 cm (2 ft) thick marks the retreat path of the Isles Dernieres. The Chandeleur barrier-island arc was generated by abandonment of the St. Bernard delta complex 1,500 years ago. Scattered outcrops of shell reefs and lagoonal deposits occur on the lower shoreface. Beyond the shoreface, a 1 to 5 m (3 to 16 ft) thick sand sheet, caps tidal inlet scars up to 10 m (33 ft) thick, as well as the basal portions of migrating barrier-island sequences associated with earlier shoreline positions. Differences seen in the two stratigraphic sequences are a function of distributary size and depositional history of each barrier-island arc. The Isles Dernieres developed from a series of small sand-deficient distributaries in the Lafourche delta complex, whereas the Chandeleur Islands developed from large sand-rich distributaries of the St. Bernard delta complex.

  15. Detrital U-Pb zircon dating of lower Ordovician syn-arc-continent collision conglomerates in the Irish Caledonides

    Science.gov (United States)

    Clift, P.D.; Carter, A.; Draut, A.E.; Long, H.V.; Chew, D.M.; Schouten, H.A.

    2009-01-01

    The Early Ordovician Grampian Orogeny in the British Isles represents a classic example of collision between an oceanic island arc and a passive continental margin, starting around 480??Ma. The South Mayo Trough in western Ireland preserves a complete and well-dated sedimentary record of arc collision. We sampled sandstones and conglomerates from the Rosroe, Maumtrasna and Derryveeny Formations in order to assess erosion rates and patterns during and after arc collision. U-Pb dating of zircons reveals a provenance dominated by erosion from the upper levels of the Dalradian Supergroup (Southern Highland and Argyll Groups), with up to 20% influx from the colliding arc into the Rosroe Formation, but only 6% in the Maumtrasna Formation (~ 465??Ma). The dominant source regions lay to the northeast (e.g. in the vicinity of the Ox Mountains, 50??km distant, along strike). The older portions of the North Mayo Dalradian and its depositional basement (the Annagh Gneiss Complex) do not appear to have been important sources, while the Connemara Dalradian only plays a part after 460??Ma, when it supplies the Derryveeny Formation. By this time all erosion from the arc had effectively ceased and exhumation rates had slowed greatly. The Irish Grampian Orogeny parallels the modern Taiwan collision in showing little role for the colliding arc in the production of sediment. Negligible volumes of arc crust are lost because of erosion during accretion to the continental margin. ?? 2008 Elsevier B.V.

  16. Technological challenges in thermal plasma production

    International Nuclear Information System (INIS)

    Thermal plasmas, generated by electric arc discharges, are used in a variety of industrial applications. The electric arc is a constricted electrical discharge with a high temperature in the range 6000-25,000 K. These characteristics are useful in plasma cutting, spraying, welding and specific areas of material processing. The thermal plasma technology is an enabling process technology and its status in the market depends upon its advantages over competing technologies. A few technological challenges to enhance the status of plasma technology are to improve the utilisation of the unique characteristics of the electric arc and to provide enhanced control of the process. In particular, new solutions are required for increasing the plasma-material interaction, controlling the electrode roots and controlling the thermal power generated by the arcing process. In this paper, the advantages of plasma technology, its constraints and future challenges for technology developments are highlighted. 36 refs., 14 figs

  17. Corrosion behavior of Zr modified CrN coatings using metal vapor vacuum arc ion implantation

    International Nuclear Information System (INIS)

    In recent years, attention has focused on the use of alternative metal nitride coatings as replacements for TiN for not only improved wear resistance and surface hardness but also for increased corrosion resistance in selected environments. While these coatings display excellent wear resistance and surface hardness, like many nitride coatings, their corrosion behavior is determined to a large extent by the presence of defects such as pinholes within the coating. Improved corrosion resistance is expected through minimizing the porosity/number of pinholes within the coating, through postdeposition surface modification. The aim of this study was to modify the surface of CrN coatings using metal vapor vacuum arc ion implantation. CrN coatings were deposited on AISI 316 stainless steel and AISI 1020 mild steel substrates using physical vapor deposition technology, followed by implantation of Zr ions into the coating at doses varying from 6x1016 to 2x1017 ions/cm2. The corrosion behavior was assessed in saline environments using linear polarization techniques and the corroded surface of the coatings was characterized using x-ray photoelectron spectroscopy and scanning electron microscopy. The results of the study showed that implantation of Zr ions into CrN resulted in a lowering of the corrosion current density, suggesting improved corrosion resistance. This was though to be associated with two factors. Firstly, partial closure of the pinholes as a result of the implantation process and secondly, the formation of ZrN, CrZrN, and various oxynitrides/oxides at the surface

  18. Robust TaNx diffusion barrier for Cu-interconnect technology with subnanometer thickness by metal-organic plasma-enhanced atomic layer deposition

    International Nuclear Information System (INIS)

    TaNx diffusion barriers with good barrier properties at subnanometer thickness were deposited by plasma-enhanced atomic layer deposition (PE-ALD) from pentakis(dimethylamino)Ta. Hydrogen and/or nitrogen plasma was used as reactants to produce TaNx thin films with a different nitrogen content. The film properties including the carbon and oxygen impurity content were affected by the nitrogen flow during the process. The deposited film has nanocrystalline grains with hydrogen-only plasma, while the amorphous structure was obtained for nitrogen plasma. The diffusion barrier properties of deposited TaN films for Cu interconnects have been studied by thermal stress test based on synchrotron x-ray diffraction. The results indicate that the PE-ALD TaN films are good diffusion barriers even at a small thickness as 0.6 nm. Better diffusion barrier properties were obtained for higher nitrogen content. Based on a diffusion kinetics analysis, the nanocrystalline microstructure of the films was responsible for the better diffusion barrier properties compared to polycrystalline PE-ALD TaN films deposited from TaCl5

  19. PARAMETRIC STUDY FOR THE PREPARATION OF ALIGNED SINGLE-WALLED CARBON NANOTUBES BY ANODE-ARC DISCHARGE METHOD

    Institute of Scientific and Technical Information of China (English)

    J.F. Dai; Q. Wang; W.X. Li; Z.Q. Wei; G.J. Xu

    2005-01-01

    Well aligned quasi-straight single-walled carbon nanotubes (SWCNTs) and straight SWCNTs bundle have been prepared in large scale by anode-arc vaporization of graphite with metallic catalysts. Various parameters such as the catalyst preparation, the kinds and pressure of the buffer gases, the quantity of anode-arc current intensity, and the method of purification have been examined. The influence of these parameters on the deposited carbon yield is reported, together with observations of the produced material. Improvement in synthetic techniques has resulted in the optimal conditions for the production of large quantities of high quality SWCNTs in our semi-continuous synthesis method. The formation of carbon nanotubes (CNTs) was studied briefly in this paper. Owing to the magnetic pinching effect of arc current, the CNTs arrange in parallel lines along the arc current direction.

  20. THE EFFECTS OF NEGATIVE BIAS AND FLUX RATIO ON THE PROPERTIES OF TiN THIN FILMS FORMED BY FILTERED CATHODIC ARC PLASMA TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Y.J. Zhang; P.X. Yan; Z.G. Wu; W.W. Zhang; J. Wang; Q.J. Xue

    2005-01-01

    The filtered cathodic vacuum-arc (FCVA) technique is a supplementary and alternative technique with respect to convendtional physical and chemical vapour deposition which can remove macro-particles effectively and make the deposition process at ambient temperature.In this work, high quality TiN thin films were deposited on silicon substrates at low temperature using the improved filtered cathodic arc plasma (FCAP) technique. AFM, XRD, TEM were employed to characterize the TiN thin films. The effects of the negative substrate bias on the grain size, preferred crystalline orientation, surface roughness of TiN thin films were discussed.