Effects of Ce addition on the oxidation behavior of Ni-28W-6Cr superalloy

The oxidation behavior of Ni-28W-6Cr-(0-0.190 wt%)Ce alloys at 850 degrees C was investigated. The addition of Ce significantly decreases the oxidation rate of the alloys and the thickness of the inner oxide scale when the Ce content is below 0.023 wt%. Then the decrease slows down when the Ce content reaches 0.190 wt% due to the consumption of Ce in the gamma matrix caused by the formation of Ni-Ce phase. Ce is solid-soluted in the inner oxide NiWO4 and replaces the Ni2+ by Ce with the valence of + 3 and + 4, therefore, the formation of oxygen vacancies and oxygen diffusion are inhibited.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The oxidation behavior of Ni-28W-6Cr-(0-0.190 wt%) Ce alloys at 850 degrees C was investigated. The addition of Ce significantly decreases the oxidation rate of the alloys and the thickness of the inner oxide scale. However, the decrease slows down when the Ce content reaches 0.190 wt% due to the formation of Ni-Ce phase. Ce is solid-soluted in the inner oxide and replaces Ni2+ to capture oxygen, inhibiting the formation of oxygen vacancies and oxygen diffusion.