Aluminothermic reaction path in the synthesis of a TiB₂–Al₂O₃ composite

Differential thermal analysis, in air and argon, in concert with x-ray diffraction, was performed on 2- and 3-component mixtures of Al, B₂O₃, and TiO₂, to foster an understanding of the reaction path involved in the TiB₂-forming thermite reaction. In argon, aluminum reacted with B₂O₃ to form elemental boron, and reacted with TiO₂ to form AlTi₃. These two products reacted just after boron was made available at ∼1060 °C to form TiB₂. Formation of Al₁₈B₄O₃₃ by reaction between B₂O₃ reactant and Al₂O₃ product attenuated the yield of TiB₂, but facilitated its formation by extraction of Al₂O₃ reaction barriers.