Begell House Inc.
High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes
HTM
1093-3611
11
3
2007
INVESTIGATION OF IN-FLIGHT PARTICLE CHARACTERISTICS AND MICROSTRUCTURAL EFFECTS ON OPTICAL PROPERTIES OF YSZ PLASMA-SPRAYED COATINGS
309-320
10.1615/HighTempMatProc.v11.i3.10
V.
Debout
CNRS - SPCTS, University of Limoges, Limoges, France
Armelle
Vardelle
ENSIL, ESTER Technopole, 87068 Limoges - France
P.
Abelard
CNRS - SPCTS, University of Limoges, Limoges, France
Pierre
Fauchais
Laboratoire Sciences des Procedes Ceramiques et de Traitements de Surface UMR CNRS 6638 University of Limoges 123 avenue Albert Thomas, 87060 LIMOGES - France
Erick
Meillot
CEA/DAM Le Ripault, BP 16 - 37260 Monts - France
E.
Bruneton
СЕA-DAM Le Ripault, BP 16, 37260Monts, France
Franck
Enguehard
Institut Pprime, CNRS, Universite de Poitiers, ISAE-ENSMA 86962, Futuroscope Chasseneuil, France
S.
Schelz
CEA Le Ripault, Monts, France
The purpose of this study is to investigate the microstructural effects of yttria-stabilized zirconia (YSZ) plasma-sprayed coatings on their optical properties in order to improve the thermal performance of these coatings that are often used as thermal barrier coatings (TBCs). Four coatings with significant microstructural differences have been manufactured. A preliminary investigation of in-flight particle characteristics has been performed to select the spray conditions. This investigation used two complementary particle diagnostic tools: the DPV2000 system and a particle collection device. Both hemispherical transmittance and reflectance spectra of the coatings have been investigated over the 0.25−10 μm wavelength range. The Gouesbet-Maheu four-flux model has been implemented to calculate the absorption and scattering coefficients. Their variations are discussed in terms of microstructural effects.
OPEN POROUS METALLIC FOAMS WITH THERMAL BARRIER COATINGS AND COOLING HOLE ARRAY FOR HIGH TEMPERATURE TURBINE APPLICATIONS
321-343
10.1615/HighTempMatProc.v11.i3.20
S.
Angel
Department of Ferrous Metallurgy, IEHK, RWTH Aachen University, Intzestr. 1, 52072 Aachen
E.
Ratte
Department of Ferrous Metallurgy, IEHK, RWTH Aachen University, Intzestr. 1, 52072 Aachen
W.
Bleck
Department of Ferrous Metallurgy, IEHK, RWTH Aachen University, Intzestr. 1, 52072 Aachen
K.
Bobzin
Surface Engineering Institute (IOT), RWTH University of Technology Aachen, Augustinerbach 4-22, 52066 Aachen, Germany
Erick
Lugscheider
Werkstoffwissenschaften Lehr und Forschungsgebeit der RWTH Jiilicher Sir. 342-352 52070 Aachen; Surface Engineering Institute (IOT), RWTH University of Technology Aachen, Augustinerbach 4-22, 52066 Aachen, Germany
R.
Nickel
Surface Engineering Institute, IOT, RWTH Aachen University, Augustinerbach 4-22, 52062 Aachen, Germany
K.
Richardt
Surface Engineering Institute, IOT, RWTH Aachen University, Augustinerbach 4-22, 52062 Aachen, Germany
N.
Bagcivan
Surface Engineering Institute (IOT), RWTH University of Technology Aachen, Augustinerbach 4-22, 52066 Aachen, Germany
K.
Walther
Chair for Laser Technology, LLT, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen, Germany
E. W.
Kreutz
Chair for Laser Technology, LLT, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen, Germany
I.
Kelbassa
Chair for Laser Technology, LLT, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen, Germany
Reinhart
Poprawe
Chair for Laser Technology, LLT, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen, Germany
Open porous and high temperature resistant Ni-base structures are developed for the requirements of an effusion cooling. A metallic foam, that is produced by the SlipReactionFoamSintering (SRFS)- process, a powder metallurgical process, is used as the open porous structure. To withstand the high temperatures in the combustor of a gas turbine of up to 1520 °C the samples are covered with a Thermal Barrier Coating (TBC) using thermal spraying processes, which hermetically seals the open porous structures. Laser drilling is used to form blind holes through the TBC into the metallic foam in order to establish connections to a number of pores, which make the mass flow of the cooling fluid possible. Therefore, the pores must not be clogged by molten material during laser drilling. The aim of this paper is to point out the general feasibility of the production steps of the open porous multi-layer component made out of the open porous foam and the thermal barrier coating, which is then opened by laser drilling. First design suggestions are given for the foam pore structure to enable the application of the TBC and for the dimension of the laser drilled holes.
CHEMICAL REACTIONS IN HEAT AND MASS TRANSFER BETWEEN SMALL PARTICLES AND PLASMA
345-358
10.1615/HighTempMatProc.v11.i3.30
Jacques
Amouroux
Laboratoire de Genie des Precedes Plasmas Universite P. et M. Curie, ENSCP 11 rue P. et M. Curie 75005 Paris France
Sergey V.
Dresvin
Laboratory of Electrotechnological and Plasma Installation of Polytechnic Institute -SPb State Polytechnical University, 29 Polytechnicheskaya Str., 195251 Saint-Petersburg, Russia
D.
Ivanov
St. Petersburg State Polytechnic University, 29 Politekhnicheskaya Str., St. Petersburg, 195251, Russia
Our goal is to qualify the chemical reaction mechanisms which take place during the interaction between a RF air plasma and silicon particles.
The energy and mass transfer in the usual model take into account heat transfer from plasma by conduction and convection on the surface of the particle, radiation effect, melting, heating of vapor cloud and vaporization. So that heat and mass balance give us the possibility of modeling these processes. However exothermic reactions are able to appear between oxygen atoms and silicon which give SiO gas and strong enthalpy effect.
These mechanisms of chemical reactions between the air plasma and the silicon particles depend mainly of the plasma temperature and of the gas flow velocity. We propose to discuss the main results of this model in order to take into account the chemical mechanisms which appear on the surface plasma−powder.
ELECTROMAGNETIC AND GAS DYNAMIC CONTROL OF TRANSFERRED PLASMA ARC IN METALLURGICAL PLASMA REACTORS AND FURNACES
359-369
10.1615/HighTempMatProc.v11.i3.40
Mihail K.
Mihovsky
“PLASMALAB” - Plasma Metallurgy Research Laboratory, University of Chemical Technology and Metallurgy - Sofia, 8 “Kliment Ohridsky” Blvd., 1156, Sofia, Bulgaria
V.
Hadzhiyski
“PLASMALAB” - Plasma Metallurgy Research Laboratory, University of Chemical Technology and Metallurgy - Sofia, 8 “Kliment Ohridsky” Blvd., 1156, Sofia, Bulgaria
L.
Todorov
“PLASMALAB” - Plasma Metallurgy Research Laboratory, University of Chemical Technology and Metallurgy - Sofia, 8 “Kliment Ohridsky” Blvd., 1156, Sofia, Bulgaria
One of the advantages of plasma metallurgical technologies is the possibility for effective processing of powdered raw materials and waste. This avoids preliminary agglomeration (pelletization) which is a standard, expensive and non ecological process in the classic extractive metallurgy.
The main unit of metallurgical plasma equipment is the system Plasma torch − Plasma reactor (plasma furnace). The limit stage determining velocity and completeness of chemical processes is the heating rate and melting of powdered charge which depends mainly on plasma arc organization.
In extractive metallurgy plasma equipment preliminary uses DC transferred plasma arcs.
The existing laboratory, pilot and industrial methods for electro magnetic and gas dynamic control of DC transferred plasma arc, aiming to obtain maximum heat exchange between it and the processing charge are described in this work.
The original “PLASMALAB” system for Auto-Electro-Magnetic Rotation (AEMR) of DC transferred plasma arc in the system “Plasma torch with hollow graphite cathode − FFP- reactor (anode)” is also described.
QUASI-ONE-DIMENSIONAL APPROACH TO THE FALLING FILM REACTOR FOR THE PLASMA-BASED SMELTING- REDUCTION OF THE IRON ORE
371-381
10.1615/HighTempMatProc.v11.i3.50
P.P.
Ivanov
Science and Engineering Center for Energy-Efficient Processes and Equipment of Joint Institute for High Temperatures of Russian Academy of Sciences Izhorskaya 13/19, Moscow, 127412, Russia
E. Kh.
Isakaev
Science and Engineering Center for Energy-Efficient Processes and Equipment of Joint, Institute for High Temperatures of Russian Academy of Sciences Izhorskaya 13/19, Moscow, 127412, Russia
Oleg A.
Sinkevich
Science Technological Center of Associated Institute for High Temperature, Russian Academy of Science and Moscow Power Engineering Institute (Technical University), Russia
As a first step towards a computer simulation of the fluid dynamics in the falling film plasma reactor, two-temperature swirl flow equations are developed allowing the detailed handling of the working gas using the code for thermodynamic equilibrium in a multi-component system and for the electrical and thermal conductivity in a gas. There is an easy way to incorporate the detailed radiation data into the integration process. It is important because radiation heat loss dominates over the convective one at a substantial length of a plasmatron of the kind under consideration. The matching of the calculated data to the available experimental data is obtained using quite reasonable coefficients in the heat transfer terms.
SURFACE ALLOYING OF METALS USING A QUASI-STATIONARY PLASMA ACCELERATOR
383-391
10.1615/HighTempMatProc.v11.i3.60
Vladimir V.
Uglov
Belarusian State University, Minsk, 220030, Belarus; National Research Tomsk State University, Tomsk, 634050, Russia
Nikolai N.
Cherenda
Belarusian State University, Physics Faculty, 4 Nezavisimost Ave., Minsk, 220030, Belarus; South Ural State University, 76 Lenin Ave., Chelyabinsk, 454080, Russia
V. M.
Anishchik
Belarussian State University, 4 Nezavisimost Ave., Minsk, 220030, Belarus
A. K.
Stalmashonak
Belarusian State University, 4, F.Nezavisimosti ave., 220030 Minsk, Belarus
A. G.
Kononov
Belarusian State University, 4 Nezavisimosti ave., 220030 Minsk, Belarus
Yu. A.
Petuhov
Belarusian State University, 4 Nezavisimosti ave., 220030 Minsk, Belarus
V. M.
Astashinski
Institute of Mathematics, National Academy of Sciences of Belarus, Minsk, Belarus
Anton M.
Kuzmitski
A. V. Luikov Heat and Mass Transfer Institute, National Academy of Sciences of Belarus, 15, P. Brovki Str, Minsk 220072, Belarus
The main regularities of Al and Ni surface alloying by means of compression plasma flows treatment of Ti/Al and Zr/Ni (coating/substrate) systems were investigated in this work. X-Ray diffraction, Rutherford backscattering and scanning electron microscopy were used as investigation techniques. It was found that a mixed layer contained intermetallides (Al3Ti, Al2Ti or Ni5Zr) and nitrides (AlN, TiN or ZrN) providing microhardness increase. The phase composition of the mixed layer is correlated with the phase composition given by the equilibrium phase diagram. Thus, compression plasma flows can be effectively used for the predictable formation of a variety of alloys in the surface layer of metals by means of “coating/substrate” system treatment.
OSCILLATORY MOTION OF MAGNETICALLY DRIVEN ARC IN NON-UNIFORM FIELD
393-403
10.1615/HighTempMatProc.v11.i3.70
I.
Kuno
Department of Machine Intelligence and System Engineering, Akita Prefectural University, 84-4 Ebinokuchi Tsuchiya, Yuri-Honjo, Akita, 015-0055, Japan
T.
Yamamoto
Department of Machine Intelligence and System Engineering, Akita Prefectural University, 84-4 Ebinokuchi Tsuchiya, Yuri-Honjo, Akita, 015-0055, Japan
Koichi
Takeda
Department of Machine Intelligence and System Engineering, Akita Prefectural University, 84-4 Ebinokuchi Tsuchiya, Yuri-Honjo, Akita, 015-0055, Japan
Takehiko
Toh
Environment & Process Development Center, Nippon Steel Corp., 20-1, Shintomi, Futtu, Chiba, 293-8511, Japan
Jim
Tanaka
Environment & Process Development Center, Nippon Steel Corp., 20-1, Shintomi, Futtu, Chiba, 293-8511, Japan
Ken-ichi
Yamamoto
Environment & Process Development Center, Nippon Steel Corp., 20-1, Shintomi, Futtu, Chiba, 293-8511, Japan
Sunao
Takeuchi
Environment & Process Development Center, Nippon Steel Corp., 20-1, Shintomi, Futtu, Chiba, 293-8511, Japan
The authors have developed a wide heat source by imposing an alternating magnetic field perpendicularly to a transferred arc. In this paper, the deformation of the arc root on the anode is examined theoretically. In a uniform magnetic field, the arc root area increases with the increased arc displacement from the center. The increase of the area decreases the heat flux density. The application of the non-uniform magnetic field is discussed to prevent the decrease of the heat flux density. If the reversed magnetic field is applied to the arc near the anode, the incident angle of the arc to the anode becomes large (close to π/2 ). In other words, the application of such a non-uniform field might suppress the increase of the area of the arc root. Consequently, it might suppress the decrease of the heat flux density. Theoretical prediction of the effect of the non-uniform field is confirmed experimentally.
AN INVERSE METHOD FOR THE EXPERIMENTAL CHARACTERIZATION OF AN ANODE MATERIAL − HEAT FLUX AND TEMPERATURE FIELD
405-419
10.1615/HighTempMatProc.v11.i3.80
M.
Masquere
AEPPT Team, LAPLACE, UMR CNRS5213, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse III, Cedex 09, France
P.
Freton
Laboratoire Plasma et Conversion d'Energie, UMR UPS-INP-CNRS5213, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse cedex 9, France
J. J.
Gonzalez
Laboratoire Plasma et Conversion d'Energie, UMR UPS-INP-CNRS5213, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse cedex 9, France
This paper deals on the quantification of the energy transferred between and electric arc plasma and a copper anode material. The aim consists in an experimental tool development and a validation of the numerical method. The experimental tool is based on the conjugate gradient method and allows obtaining, through some punctual temperatures in the anode by thermocouples, the total temperature field in the material and the applied flux at its surface. In a first time the experimental device is presented. It consists on a transferred arc configuration, in an argon gas for current intensities around one hundred amps. Then the main lines of the mathematical method are presented and tested through two heat flux profiles. Before applying the method to the experimental setup, a parametric study is made on the captor's positions and on their number. Finally the tool is applied to our experimental configuration in order to quantify the flux at the anode surface and to determine the temperature field in the material. In the described configuration, for a current intensity equal to 90A, the deduced flux is applied on a radius of 5mm with a maximum value of 3.5×107 W.m−2.
INVESTIGATION OF RADIAL ENERGY FLOWS IN AN ARC HEATER CHANNEL
421-430
10.1615/HighTempMatProc.v11.i3.90
J.
Gregor
Faculty of Electrical Engineering and Communication, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic
I.
Jakubova
Faculty of Electrical Engineering and Communication, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic
J.
Senk
Faculty of Electrical Engineering and Communication, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic
The integral quantities measured on an arc heater where the electrical arc is stabilized by flowing gas serve as input data of a mathematical-physical model of phenomena inside the arc heater channel. The model is based on the mass and energy conservation equations and Ohm law and uses the known material properties of the gas medium. The main simplifying assumptions are LTE, relatively small kinetic energy of plasma, and axial symmetry of the investigated area. The main measured values are the arc current I (50 to 220 A), the arc voltage U (approx. 100 volts), the flow rate of the working gas G (argon, up to 22 g/s), energy loss of the arc heater channel Pz determined from the warming of the cooling water. By means of the mentioned model, the energy flows in axial (enthalpy flow) and radial (conduction and radiation energy loss) directions are computed and presented in diagrams.
SHEATH CHARACTERISTICS OF AN EXCIPLEX XE-NE-HCL LAMP PUMPED BY PHOTO TRIGGERED DISCHARGE
431-441
10.1615/HighTempMatProc.v11.i3.100
S.
Bendella
Laboratory of Plasma physics, Materials conducting and their Applications Faculty of science. Department of Physics U.S.T.O.MB El M'NAOUERB.P 1505, Oran, ALGERIA
Ahmed
Belasri
Laboratoire de Physique des Plasmas, Matériaux Conducteurs et leurs Application (LPPMCA), Université des Sciences et de la Technologie d'Oran, USTO-MB, Algérie
The role of the cathode layer in Xenon- Neon- HCl photo triggered discharge for exciplex lamps is studied in this work. We developed a one-dimensional model of the cathode sheath coupled to a kinetics model of plasma and with the external circuit. The one-dimensional model is based on the resolution of the equations of continuity with the Poisson's equation. In the kinetics model, the plasma is represented by a variable value of resistance in time. The electric and kinetic parameters of the discharge are discussed and analysed.
COLOR SEGREGATION IN METAL-HALIDE LAMPS: EXPERIMENTAL AND NUMERICAL INVESTIGATIONS
443-454
10.1615/HighTempMatProc.v11.i3.110
W. J. M.
Brok
Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
T.
Nimalasuriya
Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
A.
Hartgers
Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
M. L.
Beks
Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
M.
Haverlag
Philips Lighting, Central Development Lamps, P.O. Box 80020, 5600 JM Eindhoven, The Netherlands; and Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
W. W.
Stoffels
Eindhoven University of Technology, Department of Applied Physics, P.O.Box 513, DenDolech 2, Eindhoven, the Netherlands
Joost J. A. M.
van der Mullen
Department of Applied Physics, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands
The COST reference lamp is a High Intensity Discharge (HID) Metal-Halide (MH) lamp that has been designed to introduce a unified lamp system used in experimental investigations and numerical simulations done by various groups working on HID lamps. By using this lamp, designed to be accessible for a variety of diagnostic techniques, measurements of various plasma parameters can be fitted together to obtain a more complete understanding of the physics of these lamps. In this paper we discuss the mechanisms responsible for colour segregation in MH lamps. The discussion is aided by experimental and numerical data obtained from studies of the COST lamp: emission spectroscopy under varying gravity conditions, x-ray induced fluorescence and numerical modelling by means of the two-dimensional fluid model toolkit Plasimo.
MEASURING ELECTRIC FIELDS WITH LASER-INDUCED FLUORESCENCE-DIP STARK SPECTROSCOPY
455-465
10.1615/HighTempMatProc.v11.i3.120
E.
Wagenaars
Dept. of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, Netherlands
M.D.
Bowden
Department of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA, United Kingdom
G. M. W.
Kroesen
Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
The electric field is an important quantity in low-pressure gas discharges, driving many fundamental processes. Unfortunately, it is difficult to measure electric field distributions in plasmas directly. The goal of this research was to develop a diagnostic technique to measure electric fields in low-pressure xenon discharges. It was based on measuring Stark effects in Rydberg levels of xenon atoms by laser-induced fluorescence-dip spectroscopy. With our experimental arrangement we could measure electric fields ranging from 1000 to 4000 V/cm with an accuracy between 150 and 300 V/cm.
INFLUENCE OF NEGATIVE SUBSTRATE BIAS ON PLASMA PROPERTIES AND SILICON FILM DEPOSITION RATE
467-475
10.1615/HighTempMatProc.v11.i3.130
E.
Katsia
Plasma Technology Lab, Dept. Chem. Engineering, University of Patras, P.O.Box 1407, 26500 Patra, Greece
P.
Gkotsis
Plasma Technology Lab, Dept. Chem. Engineering, University of Patras, P.O.Box 1407, 26500 Patra, Greece
Dimitrious E.
Rapakoulias
Plasma Technology Lab, Dept. Chem. Engineering, University of Patras, P.O.Box 1407, 26500 Patra, Greece
The role of substrate bias on the properties of the discharge and on silicon film deposition was investigated. In order to isolate the bias effect on the deposition procedure the experiments were carried out under conditions of constant power dissipation and pressure. The applied negative bias voltage induces changes on the electrical characteristics (voltage, current, impedance) of the discharge affecting the electron density and consequently radical production rate. Furthermore, the applied substrate bias causes a decrease on the deposition rate, which could be attributed mainly to the modification of the product species density by the change of plasma -sustaining mechanism.