Niobium hydrogenation process: Effect of temperature and cooling rate from the hydrogenation temperature

High-purity niobium powder can be produced via the hydrogenation and dehydrogenation processes. The present work aimed at the effect of temperature and cooling rate conditions on the niobium hydrogenation process using hydrogen gas. The hydrogen contents of the materials were evaluated by weight change and chemical analysis. X-ray diffraction (XRD) was performed to identify and determine the lattice parameters of the formed hydride phases. No hydrogenation took place under isothermal conditions, only during cooling of the materials. Significant hydrogenation occurred in the 500 °C and 700 °C experiments, leading to the formation of a β-NbH x single-phase material.