Reaction with hydrofluoric acid of oxygen‐ and hydrogen‐containing zirconium and the structure of the alloy

Abstract

From dissolution experiments of the respective zirconium alloys in HF it is shown that oxygen is not occluded in zirconium, but is bound to form domains of ionised ZrO2, which may agglomerate to ZrO2 grains, sparingly soluble in HF while the alloy is soluble in dilute HF. Conversely, hydrogen is occluded or dissolved in zirconium (forming ZrHx), but probably only in those parts of the metal which are free of Zr4+ and O2‐ ions (of ZrO2). Thus the solubility of H2 in this free Zr should be higher than that usually reported by various authors who consider only the weight of oxygen. When ZrHx is dissolved in HF, the Hx is quantitatively liberated as a gas; ZrO2 when present in the samples and especially when present as a surface film remains as a residue.