Abstract
The water-cooled supersonic two-stage high-velocity oxy-fuel (HVOF) thermal spray gun was developed to make a coating of temperature-sensitive material, such as titanium, on a substrate. The gun has a combustion chamber (CC) followed by a mixing chamber (MC), in which the combustion gas is mixed with the nitrogen gas at room temperature. The mixed gas is accelerated to supersonic speed through a converging-diverging (C-D) nozzle followed by a straight passage called the barrel. This paper proposes an experimental procedure to estimate the cooling rate of CC, MC and barrel separately. Then, the mathematical model is presented to predict the pressure and temperature in the MC for the specific mass flow rates of fuel, oxygen and nitrogen by assuming chemical equilibrium with water-cooling in the CC and MC, and frozen flow with constant specific heat from stagnant condition to the throat in the CC and MC. Finally, the present mathematical model was validated by comparing the calculated and measured stagnant pressures of the CC of the two-stage HVOF gun.
Similar content being viewed by others
References
Browning, J.A., Internal Burner Type Flame Spray Method and Apparatus having Material Introduction into an Overexpanded Gas Stream, US Patent No 4,568,019, (1986).
Kawakita, J., Kuroda, S., Krebs, S., Katanoda, H.: In-situ Densification of Ti Coatings by the Warm Spray (Two-Stage HVOF) Process, Mater. Trans., vol.47(7), pp.1631–1637, (2006).
Kawakita, J., Kuroda, S., Fukushima, T., Katanoda, H., Matsuo, K., Fukanuma, H., Dense Titanium Coatings By Modified HVOF Spraying, Surf. Coat. Technol., vol.201(3–4), pp.1250–1255, (2006).
Kawakita, J., Katanoda, H., Watanabe, M., Yokoyama, K. and Kuroda, S., Warm Spraying: An Improved Spray Process to Deposit Novel Coatings, Surf. Coat. Technol., vol.202(18), pp.4369–4373, (2008).
Kuroda, S., Kawakita, J., Watanabe, M. and Katanoda, H., Warm Spraying — A Novel Coating Process Based on High-Velocity Impact of Solid Particles., Sci. Technol. Adv. Mater., vol.9(1), pp.1–17, (2008).
Gordon, S. and McBride, B.J., Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications, I Analysis, NASA Reference Publications 1311, 55 pages (1994).
Katanoda, H., Kiriaki, T., Tachibanaki, T., Kawakita, J., Kuroda, S. and Fukuhara, M., Mathematical Modeling and Experimental Validation of the Warm Spray (Two-Stage HVOF) Process, J. Thermal Spray Technol., vol.18(3), pp.401–410, (2009).
Thorpe, M. L., Richter, H. J., A Pragmatic Analysis and Comparison of HVOF Processes, J. Thermal Spray Technol., vol.1(2), pp.161–170, (1992).
Murakami, A., Empirical Method of Total Pressure Loss Estimation of Subsonic Diffuser, JAXA-RM-04-002, 17 pages, Tokyo, (2004).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Katanoda, H., Morita, H., Komatsu, M. et al. Experimental and numerical evaluation of the performance of supersonic two-stage high-velocity oxy-fuel thermal spray (Warm Spray) gun. J. Therm. Sci. 20, 88–92 (2011). https://doi.org/10.1007/s11630-011-0440-2
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11630-011-0440-2