摘要 |
A method for improving the thermal fatigue life of a thermal barrier coating (TBC) deposited on an aluminide bond coat through a process by which the surface morphology of the aluminide bond coat is modified to eliminate or at least reduce oxidation and oxidation-induced convolutions at the alumina-bond coat interface, as explained more fully below. The bond coat is deposited to have generally columnar grains and grain boundary ridges at its surface, and is then peened at an intensity sufficient to flatten at least some of the grain boundary ridges, but insufficient to cause recrystallization of the bond coat when later heated, such as during deposition of the thermal barrier coating. In so doing, the original surface texture of the bond coat is altered to be smoother where the grain boundaries meet the bond coat surface, thereby yielding a smoother bond coat surface where the critical alumina-bond coat interface will exist following oxidation of the bond coat.
|