Combustion synthesis of mullite–titanium boride composite

Mullite/TiB2 composite has been prepared successfully by combustion synthesis from blends of fine TiO2–B2O3–Al–SiO2 powders. Despite the dilution effect due to silica addition and the endothermic character of mullite formation reaction, thermodynamic calculation shows that the overall reaction between the reactants is still highly exothermic. Depending on the silica grain size and the preheating temperature, partial to full conversion of reactants into products can be achieved during the process. At 550 °C preheating temperature, complete conversion of the reactants to mullite/TiB2 was achieved. Adiabatic combustion temperature and mullite molten fraction are calculated as a function of preheating temperature.