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Journal of Thermal Spray Technology

, Volume 16, Issue 4, pp 506–511 | Cite as

On-Line Measurement of Plasma-Sprayed Ni-Particles during Impact on a Ti-Surface: Influence of Surface Oxidation

  • M.F. Bahbou
  • P. Nylén
Peer Reviewed

Abstract

The objective of this study was to analyze the impact of plasma-sprayed Ni5%Al particles on polished and grit-blasted Ti6Al4V samples under oxidized and nonoxidized conditions. For this purpose, measurements of thermal radiation and velocity of individual plasma-sprayed particles were carried out. From the thermal radiation at impact, splat diameter during flattening and temperature evolution during cooling were evaluated. Characteristic parameters related to the quality of contact between the splat and the substrate were retrieved. The flattening speed was introduced to characterize wetting, while the cooling rate was used to characterize solidification. The idea was to get a signature of particle impact for a given surface roughness and oxidation state by identifying parameters which strongly affect the splat behavior. Sieved Ni5%Al powder in a narrow range (+65 −75 μm) was sprayed on four sets of titanium alloy surfaces, consisting of polished and grit-blasted samples, one set had a nonoxidized surface and the other one was oxidized in an oven at 600 °C for two hours. Resulting splats after impact were characterized by scanning electron microscopy, the splats on oxidized surface showed pores in their core and detached fingers at the periphery. The cooling rate and flattening degree significantly increased on the oxidized smooth surface compared to the nonoxidized one. This trend was not found in grit-blasted surfaces, which implies that impact phenomena are different on grit-blasted surfaces than on smooth surfaces thus further work is needed.

Keywords

coating-substrate interaction plasma spray forming roughness effects splats cooling 

Notes

Acknowledgments

The authors would like to gratefully acknowledge the kind assistance of P. Gougeon who helped in building-up the experimental setup and took part in many discussions and M. Ottosson for his help in construction of the computer program.

References

  1. 1.
    M. Fukumoto, S. Katoh, I. Okane 1995 Splat behavior of plasma sprayed particles on flat substrate surface. In: Akira Ohmori (Ed.) Thermal Spraying: Current Status and Future Trends. Kobe, Japan: High Temperature Society of Japan, pp. 353-358 May 22-26, 1995Google Scholar
  2. 2.
    M. Fukumoto, Y. Huang 1999 Flattening Mechanism in Thermal Sprayed Ni Particles Impinging on Flat Substrate Surface. J. Thermal Spray Technol. 8(3): 427–432CrossRefGoogle Scholar
  3. 3.
    P. Fauchais, M. Fukumoto, A. Vardelle, M. Vardelle 2004 Knowledge Concerning Splat Formation: An invited Review. J. Thermal Spray Technol. 13(3): 337–360CrossRefGoogle Scholar
  4. 4.
    M. Pasandideh-Fard, V. Persin, S. Chandra, J. Mostaghimi 2002 Splat Shapes in a thermal Spray Coating Process: Simulation s and experiments. J. Thermal Spray Technol. 11(2): 206–217CrossRefGoogle Scholar
  5. 5.
    C. Moreau, P. Gougeon, M. Lamontagne 1995 Influence of Substrate Preparation on the Flattening and Cooling of Plasma-Sprayed Particles. J. Thermal Spray Technol. 4(1): 25–33CrossRefGoogle Scholar
  6. 6.
    J. Madejski 1983 Droplets on impact with a solid surface. Int. J. Heat Mass Transfer 26: 1095–1098CrossRefGoogle Scholar
  7. 7.
    S. Aziz, S. Chandra 2000 Impact, Recoil and Splashing of Molten Metal Droplets. Int. J. Heat Mass Transfer 43(16): 2841–2857CrossRefGoogle Scholar
  8. 8.
    M. Fukumoto, H. Nagai and T. Yasui, Influence of Surface Character Change of Substrate due to Heating on Flattening Behavior of Thermal Sprayed Particle, Proceedings of the 2006 International Thermal Spray Conference, 2006Google Scholar
  9. 9.
    J. Cedelle, M. Vardelle, P. Fauchais, Effect of Substrate Surface Topography and Temperature, on Millimeter and Micrometer Sized Splat Formation and on Thermal Contact Resistance, Proceedings of the 2006 International Thermal Spray Conference, 2006Google Scholar
  10. 10.
    A.G. McDonald, S. Chandra, M. Lamontagne, and C. Moreau, Photographing Impact of Plasma-Sprayed Particles on Metal Substrates, Proceedings of the 2006 International Thermal Spray Conference, 2006Google Scholar
  11. 11.
    A. McDonald, M. Lamontagne, C. Moreau, S. Chandra (2006) Impact of Plasma-sprayed Metal Particles on Hot and Cold Glass Surface. Thin Solid Films 514: 212–222CrossRefGoogle Scholar
  12. 12.
    H. Li, S. Costil, H.-L. Liao, C.-J. Li, Planche, C. Coddet 2006 Effects of surface conditions on the flattening behavior of plasma sprayed Cu splats. Surf. Coat. Technol. 200(18-19): 5435–5446CrossRefGoogle Scholar
  13. 13.
    P. Gougeon, C. Moreau 2001 Simultaneous Independent Measurement of Splat Diameter and Cooling Time during Impact on a Substrate of Plasma Sprayed Molybdenum Particles. J. Thermal Spray Technol. 10(1): 76–82CrossRefGoogle Scholar
  14. 14.
    Mansoor A. Khan, Charly Allemand, Thomas W. Eager 1991 Noncontact Temperature measurement. I. Interpolation based Techniques. Rev. Sci. Instrum. 62(2): 392–402CrossRefGoogle Scholar
  15. 15.
    K.C. Mills, Recommended values of thermo physical properties for selected commercial alloys, ASM International, 2002Google Scholar

Copyright information

© ASM International 2007

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringUniversity WestTrollhattanSweden
  2. 2.TrollhattanSweden

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