Preparation and oxidation behavior of novel CeO2/Y2O3-modified aluminide coatings on Ni using sol–gel derived/pack cementation process

CeO 2 /Y 2 O 3 -modified aluminide coatings were prepared on Ni substrate using a sol–gel derived/pack cementation process. For comparison, simple aluminide coatings were also produced on Ni substrate using the same pack cementation process. The microstructure and high temperature oxidation behavior of three aluminide coatings at 900 °C for 50 h in air were comparably analyzed using SEM/EDS and XRD. The results indicated that both CeO 2 /Y 2 O 3 -modified aluminide coatings exhibited better oxidation resistance than the CeO 2 /Y 2 O 3 -free one, because of various effects of CeO 2 /Y 2 O 3 on the oxidation including the grain refinement effect of the aluminide, the “reactive element effect”(REE) and the epitaxial template effect of Y 2 O 3 to promote the growth of α-Al 2 O 3 .