High temperature oxidation of chromium containing Y 2O 3

Abstract

Chromium containing 5 o/v Y 2O 3 was oxidized in air for periods of 100 h at temperatures ranging from 1150–1370°C. It was observed that the oxidation rate was considerably less than parabolic following an initial parabolic law period which lasted about 3–4 h. Evidence is presented that a double oxide, YCrO 3, is formed at the scale-alloy interface, and it is suggested that the formation of this oxide may constitute an increasingly effective blocking layer to continued chromium ion diffusion through the growing Cr 2O 3 layer.