Hafnium diboride has a hexagonal crystal structure, a molar mass of 200.11 grams per mole, and a density of 11.2 g/cm3.

The material has potential for use in hypervelocity reentry vehicles such as ICBM heat shields or aerodynamic leading-edges, due to its strength and thermal properties.

Unlike polymer and composite material, HfB2 can be formed into aerodynamic shapes that will not ablate during reentry.

Hafnium diboride is also investigated as a possible new material for nuclear reactor control rods.

Nanocrystals of HfB2 with rose-like morphology were obtained combining HfO2 and NaBH4 at 700-900°C under argon flow:[2] HfO2 + 3NaBH4 → HfB2 + 2Na(g,l) + NaBO2 + 6H2(g)