Microstructure and oxidation performance of a gamma-gamma ' Pt-aluminide bond coat on directionally solidified superalloy CM-247LC

摘要

The microstructure of a Pt-modified gamma-gamma' bond coat on CM-247LC Ni-base superalloy has been examined and its cyclic oxidation performance at 1100 A degrees C in air is comparatively evaluated with that of a conventional beta-(Ni, Pt)Al bond coat. The gamma-gamma' bond coat was effective in imparting oxidation resistance to the CM-247LC alloy for about 100 h, whereas the beta coating imparted oxidation resistance for significantly longer duration of about 1000 h. The nature of surface damage that occurred to the gamma-gamma' coating during oxidation has been compared with that reported in the case of beta coating.