Preparation of calcium aluminate matrix composites by combustion synthesis

CaO–Al2O3–TiB2 composites have been produced by the Combustion Synthesis technique. These materials have matrices based on binary calcium-aluminate compounds, i.e., Ca3Al2O6 (C3A), Ca12Al14O33 (C12A7), CaAl2O4 (CA), CaAl4O7 (CA2) and CaAl12O19 (CA6). Except for samples with the matrix composition of C3A, the combustion synthesis reactions can be characterized as stable self-propagating waves with combustion temperatures ranging from 2125 K to 2717 K and combustion wave velocity from 4.0 mm/s to 10.6 mm/s. For samples with a matrix composition of C12A7, CA, and CA2, predominantly equilibrium compound phase was formed, while for samples with a matrix composition of C3A, non-equilibrium phases were also present. There was no evidence of CA6 formation for samples with a matrix composition corresponding to CA6.