| 摘要 |
A multi-layer thermal barrier coating (42) for a superalloy article (40) comprises a metallic matrix coating (44) containing particles (46), a MCrAlY alloy bond coating (48) on the metallic matrix coating (44), a thin oxide layer (50) on the MCrAlY alloy bond coating (48) and a columnar grain ceramic thermal barrier coating (52). The metallic matrix coating (44) comprises a 80wt% nickel 20wt% chromium alloy. The particles (46) comprise suitable metallic compounds e.g. carbides, oxides, borides and nitrides which are selected such that they will react with harmful transition metal elements, for example titanium, tantalum and hafnium, in the superalloy substrate. One suitable compound is chromium carbide because the harmful transition metal elements will take part in an exchange reaction with the chromium in the chromium carbide to form a stable carbide of the harmful transition metal element. This reduces the amount of harmful elements in the superalloy reaching the oxide layer (50) and increases the service life of the thermal barrier coating (42). <IMAGE> |
