Degradation mechanisms of a silicon nitride in H(2)-H(2)O environments
The present research project aims at a better understanding of the fundamental mechanisms controlling the gaseous corrosion of a commercially available dense silicon nitride ceramic in H(2)-based environments. This paper highlights the results of exposing samples of Si(3)N(4) made by hot isostatic pressing in the temperature range 1200-1300 C. The oxidation behaviour was found to depend critically on the level of oxidant (pH(2)O in H(2)), gas flow, and distance between samples. For these reasons, data presented are for single specimen experiments carried out at a fixed gas flow rate. The rate of oxidation has been found to be controlled by diffusion of H(2)O to the Si(3)N(4) surface in dry H(2), whereas the reduction of SiO(2) was the rate-controlling mechanism in wet H(2).
Bibliographic Reference: Paper presented: 2nd European Ceramic Society Conference, Augsburg (DE), Sept. 11-14, 1991
Availability: Available from (1) as Paper EN 36499 ORA
Record Number: 199210062 / Last updated on: 1994-12-02
Original language: en
Available languages: en