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The oxidation behaviour of nitride powder under the condition of diffusion controlled has been investigated from both experimental and theoretical aspects. The effects of factors, such as oxidation time t, temperature T, oxygen partial pressure Po2, temperature increasing rate η and particle size R0, on the reacted fraction of oxidation have been studied, in which many factors have never been studied quantitatively before. The applications of the authors' model to both experimental data of AlN, BN and β-SiAlON powder provided by the authors' lab as well as the data of SiAlON and MgAlON powders offered by literature show that this model works well. Finally, after the calculation error comparison, it is clear to show that the authors' new model would lead to a more accurate calculation result against the model used in literatures currently. [ABSTRACT FROM AUTHOR]

Abstract: The oxidation behavior of nitride ceramic under the conditions of different rate-controlling steps existing has been investigated from theoretical aspect. A series of formulae have been introduced to express the oxidation weight gain and oxide layer thickness as a function of temperature, time and the size of materials explicitly. They give an analytic solution, which simplifies the calculation and is convenient for theoretical analysis and discussion. Available experimental data in literature for oxidation of nitride ceramic were used to evaluate the model. Good agreement was obtained between theory and experimental data. [Copyright &y& Elsevier]

Abstract: The oxidation behavior of SiAlON materials has been investigated. The kinetic studies reported in literatures were also discussed. Based on the kinetic curves of the oxidation of SiAlON, a new model for predicting the oxidation weight gain as a function of temperature and other variables was established. The application of this new model to both experiment data of β-SiAlON (z =3.0) powder and that of O′-SiAlON (x =0.18) powder as well as that of β-SiAlON-Al2O3 pellet demonstrated that this new model could be used to predict the oxidation behavior and the calculated results agreed well with the experimental data, moreover, these formulae can not only be used to treat the oxidation for SiAlON materials but also can be applied to treat the problems of other non-metallic oxide materials due to similar mechanism. [Copyright &y& Elsevier]