A thermal barrier coating for a superalloy article and a method of application thereof

摘要

A multi-layer thermal barrier coating (42) for a superalloy article (40) comprises a platinum enriched superalloy layer (44), an MCrAlY bond coating (46) on the platinum enriched superalloy layer (44), a platinum enriched MCrAlY layer (48) on the MCrAlY bond coating (46), a platinum aluminide coating (50) on the platinum enriched MCrAlY layer (48), an oxide layer (54) on the platinum aluminide coating (50) and a ceramic thermal barrier coating (56) on the oxide layer (54). The platinum aluminide coating (50) and the platinum enriched MCrAlY layer (48) reduce movement of transition metals from the superalloy substrate (40) and the MCrAlY bond coating (46) to the oxide layer (54) so that the oxide layer is very pure alumina. The platinum enriched superalloy layer (44) reduces movement of aluminium from the MCrAlY bond coating (46) to the superalloy substrate (40) so that the oxide layer (54) remains pure alumina to improve long term adhesion of the ceramic thermal barrier coating (56), and additionally reduces movement of transition metals from the superalloy substrate (40) to the oxide layer (54).