Thermal barrier coating protected by thermally glazed layer and method for preparing same

摘要

A thermal barrier coating for an underlying metal substrate of articles that operate at, or are exposed, to high temperatures, as well as being exposed to environmental contaminant compositions. This coating comprises an inner layer nearest to the underlying metal substrate comprising a ceramic thermal barrier coating material having a melting point of at least about 1093 DEG C (2000 DEG F), as well as a thermally glazed outer layer having an exposed surface and a thickness up to 0.4 mils (about 10 microns) and sufficient to at least partially protect the thermal barrier coating against environmental contaminants that become deposited on the exposed surface, and comprising a thermally glazeable coating material having a melting point of at least about 1093 DEG C (2000 DEG F) in an amount up to 100%. This coating can be used to provide a thermally protected article having a metal substrate and optionally a bond coated layer adjacent to and overlaying the metal substrate. The thermal barrier coating can be prepared by forming the inner layer comprising the ceramic thermal barrier coating material, followed by depositing the thermally glazeable coating material on the inner layer, and then thermally melting the thermally glazeable coating material to form the thermally glazed outer layer.