Diffusion model for the oxidation of hot-pressed Si sub 3 N sub 4 -Y sub 2 O sub 3 -SiO sub 2 materials

The authors discuss the results in terms of a diffusion model in which the most relevant parameters are the amount of the grain boundary phase, the width of the diffusion zone, and the concentration gradient at the Si sub 3 N sub 4 /oxide reaction interface.