| abstract |
A method for providing a substantially-smooth protective coating on a metal-based substrate is disclosed. A thermal barrier coating is first applied over the substrate by plasma-spraying. The coating is then plasma-heated according to a time- and temperature schedule sufficient to re-melt its surface region, allowing the coating material to flow and smoothen. The surface region is then allowed to cool to a temperature below its melting point. After being cooled, the surface is much smoother than when originally applied, which allows the coating to be used in a higher-temperature environment. The coating is often zirconia-based, e.g., yttria-stabilized zirconia. |