Combustion synthesis of TiO2-Al-C/Al2O3 mixture in the presence of oxygen

Abstract

Quasi-adiabatic combustion synthesis of optimized 3TiO2+4Al+(3+x)C mixture in the presence of oxygen was carried out to produce TiC-Al2O3 composite. The influence of Al2O3 diluent in combusted (3TiO2+4Al+3.5C+yAl2O3) reactant mixture was investigated. Thermodynamics studies of the system shown that self-sustaining (SS) mode of combustion wave propagation can occur for large amounts of diluents (y = 2.5). Diluent reduced combustion temperature and rate of reaction kinetics. Oxide (Ti2O, Ti3O5) and intermetallic (AlTi2) phases were detected when extra Al2O3 was added to the mixture. Semi-quantitative XRD analysis was employed to study the phase formation of products for various amounts of diluent content in the mixture. The boundary between SS and non-SS modes of wave propagation was determined. Adding Al2O3 diluent slightly increased density that resulted in better thermal conductivity.