HAFNIUM HYDRIDE

Chemical properties

-325 mesh 10μm or less with 99.8% purity; brittle solid, fcc; prepared by reacting Hf and H2 above 250°C [KIR80] [CER91]

Chemical properties

Hafnium hydride is formed as refractory, tetrahedral crystals. Hafnium hydride is usually produced as an intermediate in the process of making hafnium powder from mass hafnium metal. Hafnium reacts reversibly with hydrogen to form hydride, and the proportion of hydrogen depends upon the temperature and pressure of hydrogen used. As hydrogen is absorbed, the hafnium transforms from the hexagonal metal to the face-centered cubic hydride and then to the facecentered tetragonal hydride. Hafnium hydride is brittle and is easily crushed to very fine particles sizes.