Cyclic oxidation behavior of palladium-modified aluminide coating

(Ni,Pd)Al coating prepared by low-pressure pack cementation on the nickel-base superalloy IN738 predeposited Pd-20 wt.% Ni alloy, and their cyclic oxidation behavior was investigated by TGA, XRD, SEM/EDS and optical microscopy at 1050 °C. The (Ni,Pd)Al coatings show better cyclic oxidation resistance than simple aluminide coatings compared from the cyclic oxidation kinetics and the microstructure degradation of the two types of coatings. Palladium plays a significant role in alumina stabilization and in delaying the degradation of β-phase.