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 Tad 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.

Self-propagating high-temperature synthesis of nanomaterials

“…Similar results have been reported for syntheses of Al 2 O 3 ± TiAl ± Ti 3 Al composites 103 as well as of other inorganic powders doped with nanosized particles (ZrO 2 , Al 2 O 3 , W, WC, NbC, etc.). 104,105 The formation of nanosized particles as combustion products have also been confirmed in a series of SHS processes 19,26,80,103,105,106 utilising nanosized reactants (e.g., Y 2 O 3 , ZrO 2 , TiO 2 , C, etc.) (Table 5).…”

“…Al2O3 + TiC + ZrO2 has been described. 19 The reaction product was a mixture of crystalline TiC and ZrO 2 with amorphous Al 2 O 3 . The size of the TiC and ZrO 2 crystallites was ca.…”