Heat Diffusion in Solidifying Alumina Splat Deposited on Solid Substrate under Plasma Sprayed Conditions: Application to Coating Formation

Abstract:

A plasma-sprayed coating is built up by the layering of individual splats. The latter are formed by spreading and solidification of molten particles sprayed onto a solid substrate. The coating properties depend on its microstructure and the quality of contact between the splats and the underlying layer and between the piled-up splats. This work deals with a 1D model of heat transfer between plasma-sprayed alumina splat and smooth substrate. The model is based on heat diffusion in the solidifying splat and substrate and includes undercooling phenomenon, heterogeneous nucleation and crystal growth kinetics. It assumes that splat spreading and solidification are two independent processes. The model predicts splat cooling and solidification taking into account, as far as possible, the in-flight particle properties drawn from the literature in order to study their effect on splat thermal history. The effect of the quality of contact between the splats as well as the already-deposited and solidified layer thickness on the grain size distribution and front solidification velocity is investigated.

• Periodical: Defect and Diffusion Forum (Volumes 297-301)
• Pages: 46-51
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.297-301.46
• Online since: April 2010
• Authors: Y. Lahmar-Mebdoua, A. Vardelle, Pierre Fauchais, D. Gobin
• Keywords: Heat Transfer, Nucleation, Numerical Modeling, Plasma Spraying, Rapid Solidification, Splat Formation, Thermal Contact Resistance

References

[1] P. Fauchais, M. Fukumoto, A. Vardelle, M. Vardelle: J. Therm. Spray Technol. Vol. 13 (2004), p.337.

DOI: 10.1361/10599630419670

[2] L. Bianchi, A.C. Leger, M. Vardelle, A. Vardelle and P. Fauchais: Thin Solid Films Vol. 305 (1997), p.35.

DOI: 10.1016/s0040-6090(97)80005-3

[3] C. Escure, M. Vardelle and P. Fauchais: Plasma Chem. Plasma P. Vol. 3 (2003), p.291.

[4] J. Cedelle, M. Vardelle, P. Fauchais: Surf. Coat. Tech. Vol. 201 (2006), p.1373.

[5] M. Fukumoto, M. Shiba, H. Haji, T. Yasui: Pure Appl. Chem. Vol. 77 (2005), p.429.

[6] M. Bussmann, S.D. Aziz, S. Chandra, and J. Mostaghimi: Thermal Spray: Meeting the Challenges of the 21st Century, C. Coddet (ed. ), ASM International, Materials Park, OH, (1998), p.413.

[7] R. Dhiman, A. McDonald, and S. Chandra: Surf. Coat. Tech. Vol. 201 (2007), p.7789.

[8] J. Mostaghimi, S. Chandra, R. Ghafouri-Azar, A. Dolatabati: Surf. Coat. Tech. Vol. 163-164 (2003), p.1.

[9] C.G. Levi, V. Jayaram, J.J. Valencia, R. Mehrabian: J. Mat. Res. Vol. 3 (1988), p.969.

[10] R. Mcpherson: J. of Mat. Sci. Vol. 25 (1980), p.3677.

[11] T. Chraska, A.H. King: Thin Solid Films Vol. 397 (2001), p.40.

[12] T. Chraska, A.H. King: Thin Solid Films Vol. 397 (2001), p.30.

[13] G. -X. Wang, V. Prasad, S. Sampath and H. Hermann: in Solidification, Marsh, S.P., et al. (Eds), The Minerals, Metals & Materials Society/AIME, (1998), p.485.

[14] A. Vardelle, M. Vardelle, P. Fauchais, D. Gobin: Flash Reactions Processes, T.W. Davies Editor. Kluwer Acad. Publ. NATO Advanced Science Institute Series. Serie E, Vol. 282. (1995), p.95.

DOI: 10.1007/978-94-011-0309-1_4

[15] N. J. Ruperti, D. Gobin, R. M. Cotta: 7th Latin-American Heat and Mass Transfer Conference - ENCIT 98 (Rio de Janeiro) (1998), p.659.

[16] Y. Lahmar, A. Vardelle, P. Fauchais, D. Gobin: High Temp. Mater. P. Vol. 11-2 (2007), p.191.

[17] Y. Mebdoua: Numerical study of the thermal phenomena controlling splat solidification under plasma spray conditions: Application to the coating formation, PhD thesis (2008), Limoges University.