Abstract
Impacts of plasma-sprayed molybdenum particles were monitored by detecting thermal radiation emitted by the hot particles when they flatten on the substrate surface. Evolution of the light intensity collected at two different wavelengths was used to obtain information about flattening time, flattening degree, and cooling time of the impinging particles. Variations of these parameters with substrate surface roughness were investigated on glass and molybdenum substrates. The substrate roughness significantly influenced the flattening degree and flattening time of the particles: the smoother the substrate, the larger the surface of the splats and the longer the flattening time. The cooling time, as determined from the decay time of the light signals after impact, was shorter on smooth substrates. In this case, the temperature of the splats was not radially uniform, with a lower cooling rate at the periphery.
Similar content being viewed by others
References
J. Madejski, Solidification of Droplets on a Cold Surface,Int. J. Heat Mass Transfer, Vol 19,1976, p 1009–1013
J.Madejski, Droplets on Impact with a Solid Surface,Int. J. Heat Mass Transfer, Vol 26,1983, p 1095–1098
G. Trapaga and J. Szekely, Mathematical Modeling of the Isothermal Impingement of Liquid Droplets in Spraying Processes,Metall. Trans. B, Vol 22B, 1991, p 901–914
T. Yoshida, T. Okada, H. Hideki, and H. Kumaoka, Integrated Fabrication Process for Solid Oxide Fuel Cells Using Novel Plasma Spraying,Plasma Sources Sci. Technol, Vol 1,1992, p 195–201
T. Watanabe, I. Kuribayashi, T. Honda, and A. Kanzawa, Deformation and Solidification of a Droplet on a Cold Substrate,Chem. Eng. Sci., Vol 47,1992, p 3059–3065
A. Vardelle, M. Vardelle, R. McPherson, and P. Fauchais, Study of the Influence of Particle Temperature and Velocity Distribution within a Plasma Jet on Coating Formation,General Aspects of Thermal Spraying, J.H. Zatt, Ed., Nederlands Instituut voor Lastechniek, The Hague, 1980, p 155–161
S.J. Yankee and B.J. Pletka, Effect of Plasma Spray Processing Variations on Particle Melting and Splat Spreading of Hydroxylapatite and Alumina,J. Therm. Spray Technol., Vol 2,1993, p 271–281
S. Fantassi, M. Vardelle, A. Vardelle, and P. Fauchais, Influence of the Velocity of Plasma Sprayed Particles on the Splat Formation,Thermal Spray Coatings: Research, Design and Applications, C.C. Berndt and T.F. Bernecki, Ed., ASM International, 1993, p. 1-6
B. Borgerding, H.J. Sölter, E. Lugscheider, and K. Simhan, Modelling of Temperature Gradients and Stress-Strain Distributions during the Plasma Spraying Process,Powder Met. Int., Vol 24,1993, p 240–245
D.J. Varacalle, Jr. and W.L. Riggs II, Analytically Modeling the Plasma Spray Deposition of Tribaloy 800,Thermal Spray Coatings: Properties, Processes and Applications, T.F. Bernecki, Ed., ASM International, 1992, p 245-250
C. Moreau, M. Lamontagne, and P. Cielo, Influence of the Coating Thickness on the Cooling Rates of Plasma-Sprayed Particles Impinging on a Substrate,Surf. Coat. Technol.,Vol 53,1992,p 107–114
C. Moreau, P. Cielo, and M. Lamontagne, Flattening and Solidification ofThermally Sprayed Particles,J. Therm. Spray Technol.,Vol 1,1992, p 317–323
C. Moreau, P. Cielo, M. Lamontagne, S. Dallaire, and M. Vardelle, Impacting Particle Temperature Monitoring during Plasma Spray Deposi- tion,Meos. Sci. Technol.,Vol 1, 1990,p 807–814
R.E. Spjut, Transient Response of One- and Two-Color Optical Py- rometry,Opt. Eng., Vol 26,1987, p 467–472
J.-P. Hiernaut, R. Beukers, M. Hoch, T. Matsui, and R.W. Ohse, Determination of the Melting Point and of the Spectral and Total Emissivities of Tungsten, Tantalum, and Molybdenum in the Solid and Liquid States with a Six-Wavelength Pyrometer,High Temp. High Press., Vol 18, 1986, p 627–633
P. Gougeon and C. Moreau, In-Flight Particle Surface Temperature Measurement: Influence of the Plasma Light Scattered by the Particles,J. Therm. Spray Technol, Vol 2,1993, p 229–234
A.M. Worthington, The Splash of a Drop and Allied Phenomena,A Study of Splashes, MacMillan, 1963, p 133–162
Smithells Metals Reference Book, 6th ed., E.A. Brandes, Ed., Butter- worths, 1983, p 14–7 to 14–8
A.M. Shmakov and S.S. Ermakov, Impact Interaction of the Particle with the Substrate in Hot Gas Spraying,Phys. Chem. Mater. Treat. (USSR), Vol 20,1986, p 243–246
J.M. Houben, Future Developments in Thermal Spraying,Second National Conference on Thermal Spray, F.N. Longo, Ed., ASM International, 1984, p 1-19
M. Vardelle, A. Vardelle, P. Fauchais, and C. Moreau, Pyrometer System for Monitoring the Particle Impact on a Substrate during Plasma Spray Process,Meas. Sci. Technol., Vol 5,1994, p 205–212
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Moreau, C., Gougeon, P. & Lamontagne, M. Influence of substrate preparation on the flattening and cooling of plasma-sprayed particles. JTST 4, 25–33 (1995). https://doi.org/10.1007/BF02648525
Issue Date:
DOI: https://doi.org/10.1007/BF02648525