Effect of Y2O3 or CeO2 Fillers on the Oxidation Behavior of Aluminide Coatings by Low-temperature Pack Cementation

Abstract:

Two aluminide coatings were produced on Ni substrate via a conventional pack-cementation at 600 oC for 10 h using Y2O3 or CeO2 particles instead of part of Al2O3 as filler. For comparison, aluminizing was also performed under the same condition using pure Al2O3 as filler. The results of isothermal-oxidation at 1000 oC indicate that Y2O3 can suppress the growth of q-alumina and improve the oxidation resistance, while CeO2 accelerates the q to a-alumina transformation and significantly improves the oxidation resistance. Besides, the effects of Y2O3 or CeO2 filler on the coating oxidation behavior were discussed.

Key words:aluminide; oxidation; reactive element effect