Ceramics based on silicon nitride have been considered promising candidates for high temperature engineering applications due to their excellent refractory properties combined with high strength and good resistance to oxidation. It is well known, however, that the performance of ceramics varies considerably with chemical composition, for example with type and amount of intergranular phase. Especially the evaluation of the high temperature behavior of the ceramics under varying conditions is therefore important in increasing the knowledge of these materials. In previous articles we have interpreted the oxidation behavior of Si2N2O ceramics with use of the parabolic rate law, and a new rate law. In this article we further develop the arctan function, and also show that by an alternative mathematical approach the following rate equation can be obtained. In the following, few compare the oxidation behavior of two series of Si2N2O ceramics within the framework of the two rate laws.
1993. 521-526 p.