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

Combustion synthesis of Al2O3-TiC-ZrO2 nanoceramics by reactions in the TiO 2-Al-C-ZrO2 system is a new method with advantages of simplicity and effici ency. In this work, the effect of ZrO2 nanoparticles on the thermodynamics of combustion synthesis of the TiO2-Al-C system is studied to obtain desire d phases. The result of thermodynamic analysis shows that the adiabatic tem perature T-ad of the system stays at about 2327 K (the melting point of Al2 O3) with the addition of ZrO2 in 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 tha t the combustion product is a mixture of Al2O3-TiC-ZrO2, which coincides wi th the results obtained by x-ray diffraction and transmission electron micr oscopy.