Vacuum freeze-drying assisted preparation of spherical AlB₂ powders with ultrafine microstructure

In this paper, we report the preparation of the spherical AlB₂ powders with uniform particle size, high crystallinity and free of agglomeration. The spherical powders were fabricated by a facile solid state reaction involving the initial preparation of homogenously mixed elemental reactants via the vacuum freeze-drying method. The obtained AlB₂ powders with spherical structure and narrow size distribution showed enhanced sphericity and uniformity when being compared with the ones previously reported. The ultrafine microstructure contributed to agglomerate-free and good flowability, which could efficiently improve its combustion performance. The good antioxidative activity, stable combustion rate and high volumetric heat (53.31 kJ/g) made itself as great potential candidate as high-energy density fuel additives.