A mechanistic understanding on rumpling of a NiCoCrAlY bond coat for thermal barrier coating applications

We present a series of experimental observations on surface rumpling of an initially flat NiCoCrAlY coating deposited on a Ni-based superalloy during cyclic oxidation at 1150 °C. The extent of rumpling of the coating depends on the thermal history, coating thickness and exposed atmosphere. While the coating surface progressively roughens with cyclic oxidation, the bulk NiCoCrAlY alloys with the same nominal composition are much less susceptible...