| 摘要 |
A metallic article (50) comprises a bond coating (54) on the metallic article (50) and a ceramic thermal barrier coating (58) on the bond coating (54). The ceramic thermal barrier coating (58) comprises a plurality of columnar grains (60) extending substantially perpendicularly to the surface of the metallic article (50). Each columnar grain has a plurality of first layers (62), a plurality of second layers (66) and a plurality of third layers (64). The first layers (62) have a different structure to the second layers (66) and the third layers (64). The second layers (66) have a different structure to the third layers (64). The first layers (62) have the same composition as the third layers (64). The second layers (66) have a greater proportion of voids (68) than the first layers (62) and the third layers (64). The voids (68) reduce the thermal conductivity of the thermal barrier coating (58). The second layers (66) may also have a different composition to the first layers (62) and the third layers (64) to reduce the thermal conductivity. <IMAGE> |
