Begell House Inc.
High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes
HTM
1093-3611
13
1
2009
CHARACTERIZATION OF THE WIRE ARC SPRAY PROCESS VIA IMAGE ANALYSIS, IN-FLIGHT PARTICLE CHARACTERISTICS AND COATING PROPERTIES
1-23
10.1615/HighTempMatProc.v13.i1.10
Marie-Pierre
Planche
LERMPS, Technological University of Belfort- Montbéliard, site de Sévenans, 90010 Belfort Cedex France
Hanlin
Liao
LERMPS, Technological University of Belfort- Montbéliard, site de Sévenans, 90010 Belfort Cedex France
Ghislain
Montavon
LERMPS laboratory, University of Technology of Belfortâ€Montbéliard
Christian
Coddet
LERMPS, Université de Technologie de Belfort-Montbéliard, site de Sévenans, 90 010 Belfort Cedex
arc spray
image analysis
in-flight particle characteristics
coating properties
To have a better understanding of the physical phenomena in wire arc spraying process, we investigated droplet formation by discriminating particles resulting from the anode and the cathode wire atomization. The investigation showed that by spraying simultaneously two different materials, steel and copper, particle trajectory and their diameter distribution, the results related to the processing parameters. By analyzing the characteristics of captured particles implementing image analyses, the crossover direction of in-flight particles was demonstrated. The droplets produced by the anode were bigger than those issued from the cathode and their fraction number, which was also more important. In addition, some important modifications in particle characteristics were observed by inverting a material by the other at the anode and at the cathode. The melting temperature of copper as anode was a critical parameter and was responsible for the copper vaporization. In-flight particle characteristics (temperature, velocity, and diameter) were also determined by using a Fast-Infrared Pyrometer (FIP DPV2000 type diagnostic system). Concerning particle diameter distribution, a good agreement was discovered for the two approaches (in-flight and a posteriori analyses). Major influences of the electrode nature and the radial location on particle velocity and temperature distribution, was pointed out. Finally, quantitative analyses of coating compositions corroborated previous results. Indeed, the coating thickness distribution was largely dependent on the anode nature. Next, the role of each electrode was related to the droplets formation and thus, optimized operating parameters of the arc spray process were deduced.
EXPERIMENTAL DETERMINATION OF THERMAL PLASMA TEMPERATURES
25-44
10.1615/HighTempMatProc.v13.i1.20
J.
Benech
LAPLACE, Paul Sabatier University, 118 rte de Narbonne, Bât. 3R2 31062 Toulouse Cedex 9, 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
X.
Franceries
CPAT, UMR 5002 du CNRS, Universite Paul Sabatier, 118 route de Narbonne, 31062 TOULOUSE cedex 4, France
3D
non axisymmetry
plasma characterization
Boltzmann diagram
Abel inversion
tomography
This work is related to a theoretical study on the experimental determination of temperatures on thermal plasma medium. Three different techniques have been chosen and applied to a specific configuration: a 3D model of a transferred arc in argon; this arc is deflected by a magnetic field providing a non axisymmetric shape. Two of the chosen methods: the Boltzmann diagram and the Abel inversion are commonly used in thermal plasma domain. These methods are based on constraining assumptions on the symmetry of the studied object: plasma homogeneity along the considered direction for Boltzmann diagram and cylindrical symmetry for Abel inversion. The third considered method is named tomography and is very developed in medical imaging domain. Tomography is a technique which does not assume symmetry of the studied object, and consequently, it naturally appears to be adapted for 3D emissivity reconstruction. In this paper, tomographic reconstruction of the plasma temperature is performed with a MART (Multiplicative Algebraic Reconstruction technique) algorithm, with four projections located every 45°. However, in the whole paper, only two perpendicular directions of acquisition are simulated. Finally, the temperature profiles reconstructed by the means of each method are compared. It has been demonstrated that Boltzmann diagram and Abel inversion can lead to reconstructed profiles with important errors, as well as quantitatively than qualitatively. On the contrary, tomography with the MART algorithm gives very satisfactory results; the non axisymmetric shape of the plasma is totally respected and a relative error of about 2% - about 300K for a temperature around 15500K- is committed on the reconstructed temperature values. Therefore, the ability of tomographic reconstruction in 3D plasma characterization has been demonstrated and moreover, it could be used for 3D model validation.
INFLUENCE OF THE SELF-ABSORPTION OF ATOMIC LINES ON THE DETERMINATION OF TEMPERATURE AND ELECTRON NUMBER DENSITY IN THE CASE OF A LASER INDUCED CaCl2 − WATER PLASMA
45-59
10.1615/HighTempMatProc.v13.i1.30
Riadh
Hannachi
Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Université de Tunis El Manar, Tunis 1060, Tunisia; Laboratoire Plasma et Conversion d'Energie, UMR INP-UPS-CNRS 5213, Université Paul Sabatier, Toulouse 3, France
Philippe
Teulet
CPAT, Universite Paul Sabatier, 118, Rte de Narbonne, 31062 Toulouse Cx 4, France
Guy
Taieb
Laboratoire de Photophysique Moléculaire du CNRS, Université Paris XI, Bâtiment 210, 91405 Orsay, France
Y.
Cressault
Centre de Physique des Plasmas et de leurs Applications de Toulouse (CPAT) UMR n° 5002 − Université Paul Sabatier, 118 Route de Narbonne F31062 Toulouse Cedex 4 - France
Alain
Gleizes
Centre de Physique des Plasmas et de leurs Applications de Toulouse (CPAT) UMR n° 5002 − Université Paul Sabatier, 118 Route de Narbonne F31062 Toulouse Cedex 4 - France
Zohra Ben
Lakhdar
Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Université de Tunis El Manar, Tunis 1060, Tunisia
LIBS; optical emission spectroscopy; self-absorption; water
A spectroscopic study of the plasma plume created by a laser beam on the surface of a CaCl2 aqueous solution is presented. Optical emission spectra are recorded and temporally analyzed. The electron number density is determined from the Stark broadening of the nitrogen NI 746.8 nm atomic line and the temperature profile is obtained from the relative intensity of OI lines. To take into account the possible occurrence of the self-absorption phenomenon, the escape factor of each atomic line is computed and used to correct the measured line intensities in order to obtain reliable temperature and density profiles.
TWO-LAYER ROD ELECTRODES FOR AC PLASMA TORCHES
61-69
10.1615/HighTempMatProc.v13.i1.40
Philip G.
Rutberg
Institute of Problems of Electrophysics of Russian Academy of Sciences 191186, Russia, St. Petersburg, Dvortsovaya nab. 18
A. A.
Safronov
Institute for Electrophysics and Electric Power RAS (IEE RAS), Saint-Petersburg, Russia
V. E.
Kuznetsov
Institute for Electrophysics and Electric Power RAS (IEE RAS), Russia
S. E.
Vinogradov
Institute for Electrophysics and Electric Power RAS (IEE RAS), Russia
V. I.
Shekalov
Institute for Electrophysics and Electric Power RAS (IEE RAS), Russia
R. V.
Ovchinnikov
Institute for Electrophysics and Electric Power RAS (IEE RAS), Russia
electrode
plasma torch
erosion
arc
wear-resistance
The paper is dedicated to one of the possible methods of the solution of the problem of the wear-resistance of electrodes − to creation of two-layer (bimetallic) electrodes in which one of layers (refractory) ensures heat resistance and is located in the area of the greatest heating from the electric arc side, and another (heat-conducting) ensures an effective heat removal.
ELECTRICAL CHARACTERISATION OF VERY HIGH PRESSURE Ar/H2 LOW CURRENT ARC DISCHARGE
71-76
10.1615/HighTempMatProc.v13.i1.50
E.
Izquierdo
GEPEA-UMR-CNRS 6144, Ecole des Mines de Nantes 4, rue A. Kastler 44 307 Nantes cedex 3, France
J. Gonzales
Aguilar
Center for Energy and Processes, Ecole des Mines de Paris, Rue Claude Daunesse B.P.. 207, F-06904 Sophia-Antipolis Cedex, France ; Dpto. De Fisica Aplicada, Universidad de Cantabria, Av. Los Castros s/n, 39005 Santander, SPAIN
L.
Fulcheri
Centre D'Energetique, Ecole Des Mines De Paris; Rue Claude Daunesse, B. P. 207, F-06904 Sophia Antipolis Cedex
arc discharge
very high pressure
hydrogen/argon mixture
The characterization of low current − high pressure tip-tip arc discharges in hydrogen − argon mixtures is presented. Main investigated parameters are: inter-electrode gap, mean arc current, H2/Ar mixture ratio and pressure. This was comprised between 0.1 MPa to 15 MPa. Mean arc voltage increases with pressure, H2/Ar mixture ratio and inter-electrode gap. The V − I curves shows typical non-thermal behavior of the discharge. The high pressure seems having only poor influence on the non-thermal regime arc transition.
SPLAT HEAT TRANSFER AND CRYSTAL GROWTH UNDER THERMAL SPRAY CONDITIONS
77-91
10.1615/HighTempMatProc.v13.i1.60
Y.
Lahmar-Mebdoua
Centre de Développement des Technologies Avancées, Algiers, Algeria
Armelle
Vardelle
ENSIL, ESTER Technopole, 87068 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
Dominique
Gobin
University Paris-Saclay
A recent development in thermal spraying is to design the microstructure of coatings by controlling the sizes of the structural features within the coating so that they exhibit dimensions at the nanoscale. Improvements in performance can be in mechanical properties as well as functional properties. The size of these nano-structured features depend both on the form of the starting material (agglomerates of nanoparticles, liquid precursors) and the process conditions employed during production. Narrowing the crystal size distribution can be obtained from a carefully-controlled nucleation and growth process.
This study presents a one-dimensional heat transfer model of splat cooling and solidification under plasma spray conditions. The model involves melt undercooling, nucleation and crystal growth kinetics. It intends to investigate the effect of the oxidation of various steel substrates, on the size and density of the nucleated grains.
INVESTIGATION OF A SURFACE DIELECTRIC BARRIER DISCHARGE DEDICATED TO BOUNDARY LAYER CONTROL
93-105
10.1615/HighTempMatProc.v13.i1.70
Binjie
Dong
GREMI, UMR 6606, Universite d'Orleans, France
Dunpin
Hong
GREMI, UMR 6606, University of Orleans, France
J. M.
Bauchire
GREMI, UMR 6606, University of Orleans, France
Jean-Michel
Pouvesle
GREMI UMR 7344 CNRS/Université d'Orléans, Orléans, France
surface DBD
atmospheric plasma
EHD actuator
Use of non-thermal, atmospheric pressure plasma discharge as aerodynamic actuator for airflow boundary layer control is a promising technique and exciting research subject. Here, we present our works on this type of actuator using surface dielectric barrier discharge (DBD). Firstly, the intensity of light emitted by plasma on two sides of DBD board was measured by using a photomultiplier tube (PMT). The results suggest that light intensity increases with the thermal emission of electrode. Then, the plasma was analyzed with a high spectral resolution spectrometer; the spectra were dominated by the N2 molecular bands which enable the determination of gas temperature. Finally, measurements of plasma induced airflow in still air were also performed. The results showed a different velocity on the two sides of DBD board.
AROMATIC VOC REMOVAL BY MICROPARTICLES FORMATION IN PURE NITROGEN
107-119
10.1615/HighTempMatProc.v13.i1.80
S.
Ognier
Laboratoire de Génie des Procédés Plasmas et Traitement de Surface, Ecole Nationale Supérieure de Chimie de Paris 11 rue Pierre et Marie Curie, 75005 Paris, France
S.
Cavadias
Laboratoire Genie Precedes Plasmas - ENSCP 11, rue Pierre et Marie Curie - 75005 Paris- France
Jacques
Amouroux
Laboratoire de Genie des Precedes Plasmas Universite P. et M. Curie, ENSCP 11 rue P. et M. Curie 75005 Paris France
VOC
plasma
DBD discharge
depollution
The reactivity of toluene in a DBD discharge was studied for two different mixtures: 400 ppm of toluene diluted in synthetic air (80% N2 + 20% O2) or in pure N2. The reactivity was compared in terms of pollutant conversion and by-products formation. Regarding the pollutant conversion, the destruction efficiency was comparable with or without oxygen. However, the decomposition of toluene in pure N2 leads to the formation of micrometric particles. These particles could be easily removed by filtration. On the contrary, in the case of a DBD treatment in air, 50% of the destroyed pollutant was oxidized in CO and CO2. The other products that could be detected were ring retaining (nitroaromatics) or non ring-retaining products. In both case, the analyses of the species produced in gas-phase using GC-MS technique allows the determination of the reaction pathways.