High Temperature Oxidation of Y₂O₃ Partially-Stabilized ZrO₂ Composites Dispersed with Ni Particles

Abstract

High temperature oxidation of Y₂O₃-partially stabilized ZrO₂ composites dispersed with Ni particles was investigated at temperatures ranging from 873 to 1073 K in air. Cracks between Ni particles forms parallel to the surface during high temperature oxidation. Thickness of the cracked zone increases proportionally with increasing oxidation time. A model for the growth of the cracked zone was established as a basis of the oxidation of Ni particles by permeation of oxide ions through the Y₂O₃-partially stabilized ZrO₂ matrix, which is rate-controlled by hole conduction. Growth behavior calculated by the model is in good agreement with the experimental results.