Mechanistic and processing studies in combustion synthesis of niobium aluminides

Combustion synthesis of NbAl₃ and Nb₂Al was studied using the volume combustion mode. The effects of heating rate and green density were examined for NbAl₃ synthesis. The effect of green density was also investigated for Nb₂Al. Greater reaction completion was achieved at higher heating rates and green densities. In both NbAl₃ and Nb₂Al samples, the reaction was initiated above the melting point of Al. Quenching (Nb+3Al) samples pressed at relatively high and low densities below the ignition temperature, and results of a particle-foil experiment, identified the spreading characteristic of molten Al over Nb, providing mechanistic details about niobium aluminide product formation.