Influence of TiC additions on the oxidation behaviour of Si3N4-based ceramics

摘要

The oxidation behaviour in air of Si3N4 ceramics containing Y2O3 and Al2O3 as sintering aids, with and without a dispersion of TiC particles, has been studied between 1200 and 1400 degrees C. The influence of TiC additions on the oxidation kinetics is discussed in comparison with the results obtained for the Si3N4-Y2O3-Al2O3 reference material. However, in all cases and within the experimental temperature range, the oxidation kinetics were observed to be of a parabolic type. The microstructure of the oxide scales formed, which has been characterized by scanning and transmission electron microscopy, was observed to depend on the oxidation temperature and the initial composition of the material. (C) 1998 Chapman & Hall. [References: 14]