Abstract
Tantalum (Ta) oxide, due to its high-temperature capabilities and thermal expansion coefficient similar to silicon nitride, is a promising candidate for environmental barriers for silicon (Si) nitride-based ceramics. This paper focuses on the development of plasma-sprayed Ta oxide as an environmental barrier coating for silicon nitride. Using a D-optimal design of experiments, plasma-spray processing variables were optimized to maximize coating density. The effect of processing variables on coating thickness was also determined. X-ray diffraction (XRD) was use to ascertain that the as-sprayed coatings were comprised of α- and β-Ta2O5, but were fully converted to β-Ta2O5 after a 1200 °C heat treatment. Grain growth of the Ta2O5 followed a time dependence of t 0.2 at 1200 °C.
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Moldovan, M., Weyant, C.M., Johnson, D.L. et al. Tantalum oxide coatings as candidate environmental barriers. J Therm Spray Tech 13, 51–56 (2004). https://doi.org/10.1007/s11666-004-0049-z
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DOI: https://doi.org/10.1007/s11666-004-0049-z