Patent ID: 7807231

Claim:
A process for forming a film on a thermal barrier coating that inhibits infiltration of porosity within the thermal barrier coating by a contaminant having a melting point of up to about 1225° C. and containing oxides of calcium, magnesium, aluminum and silicon, the process comprising the steps of: applying to an outermost surface of the thermal barrier coating a deposited composition containing at least one metal chosen from the group consisting of aluminum and magnesium, the deposited composition being applied so as to form a deposited film that lies on the outermost surface of the thermal barrier coating and overlies the porosity within the thermal barrier coating beneath the outermost surface thereof; and then converting the metal within the deposited film so that the deposited film forms an oxide film containing an oxide of the at least one metal that resists infiltration of the contaminant into the thermal barrier coating, at least a portion of the oxide film forming a surface deposit on the outermost surface of the thermal barrier coating and overlying the porosity within the thermal barrier coating to close the porosity at the outermost surface of the thermal barrier coating and thereby serve as a barrier to infiltration of the contaminant into the porosity within the thermal barrier coating.