gray, hexagonal, crystal(s) solid, a=0.3141 nm, c=0.3470nm; can be prepared by heating HfO2+C+B2O3; hardness 2900 kgf/mm2; resistivity 8.8μohm· cm; used as a refractory material and as a sputtering target with 99.5% purity to produce films, which may be wear-resistant and semiconducting [HAW93] [KIR80] [CER91]
Hafnium boride is used in wear resistant coatings. It is also employed as a nuclear reactor control rod. Furthermore, it is used in hypervelocity re-entry vehicles like ICBM heat shields or aerodynamic leading-edges. It is useful in the preparation of high temperature composites in conjunction with silicon carbide (SiC).
