Tailoring the Spray Conditions for Suspension Plasma Spraying
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The plasma spray process using suspensions as liquid feedstock allows the deposition of finely structured coatings with improved properties compared to that of coatings deposited by the conventional plasma spray techniques. The evaporation of the solvent, acceleration, heating, and melting of the fine solid particles within the plasma jet take place in a shorter time, as the substrate is located closer to the plasma torch when a mono-cathode mono-anode plasma torch is used, while the liquid material processing globally consumes more energy than a powder material. Therefore, achieving a coating with the expected properties requires a broad understanding of the process. In this study, a large range of plasma spray conditions have been used to achieve yttria-stabilized zirconia coatings by suspension plasma spraying. The properties of the plasma jet (velocity, enthalpy, and stability) as well as those of droplets (trajectories, number, and size) and particles (velocity) were measured and correlated to the coating microstructure. The operating conditions necessary for obtaining disk-shape splats and achieving homogeneous coatings are described including the plasma jet properties and substrate parameters.
Keywordsparticle velocity plasma velocity suspension plasma spaying voltage fluctuations
The authors would like to thank the DGA (French Ministry of Defence) and the National R&T program of CNES (French Space Agency) for their financial support.
- 9.Z. Tang, H. Kim, I. Yaroslavski, I. Masindo, Z. Celler, and D. Ellsworth, Novel Thermal Barrier Coatings Produced by Axial Suspension Plasma Spray, Thermal Spray 2011: Proceedings of the International Thermal Spray Conference (DVS-ASM), 2011, p 571-575Google Scholar
- 12.A. Joulia, G. Bolelli, E. Gualtierie, L. Lusvarghi, S. Valerif, M. Vardelle, S. Rossignol, and A. Vardelle, Comparing the Deposition Mechanisms in Suspension Plasma Spray and Solution Precursor Plasma Spray Deposition of Yttria Stabilized Zirconia, J. Eur. Ceram. Soc., 2014, 34(15), p 3925-3940CrossRefGoogle Scholar
- 13.C. Marchand, C. Chazelas, G. Mariaux, and A. Vardelle, Liquid Precursor Plasma Spraying: Observation of Liquid Feedstock Break-up, ITSC 2008, June 02-04 (Maastricht, The Netherlands)Google Scholar
- 15.S. Goutier, J. Varin, W. Duarte, A. Joulia, and A. Vardelle, Laser Diagnostic Techniques for Suspension and Solution Plasma Spraying, Proceedings of ITSC 2014, May 21-24 (Barcelona), DVS-Berichte, Vol 302, p 634-640Google Scholar