Thermodynamic analysis of combustion synthesis of Al₂O₃–TiC–ZrO₂ nanoceramics

Abstract

Combustion synthesis of Al₂O₃–TiC–ZrO₂ nanoceramics by reactions in the TiO₂–Al–C–ZrO₂ system is a new method with advantages of simplicity and efficiency. In this work, the effect of ZrO₂ nanoparticles on the thermodynamics of combustion synthesis of the TiO₂–Al–C system is studied to obtain desired phases. The result of thermodynamic analysis shows that the adiabatic temperature T_ad of the system stays at about 2327 K (the melting point of Al₂O₃) with the addition of ZrO₂in the range of 0–15 wt% and the fraction of molten Al₂O₃ varied from 100% to 78%. The possible combustion products are discussed with an approach of an overlapped phase stability diagram of the Al–O–N, Ti–O–N, Zr–O–N, and C–O–N systems at 2300 K. It has been shown that the combustion product is a mixture of Al₂O₃–TiC–ZrO₂, which coincides with the results obtained by x-ray diffraction and transmission electron microscopy.