The preparation of Zr-deuteride and phase stability studies of the Zr-D system

• Published in: Journal of nuclear materials 2017-03, Vol.485, p.243-252
• Main Authors: Maimaitiyili, T., Steuwer, A., Bjerkén, C., Blomqvist, J., Hoelzel, M., Ion, J.C., Zanellato, O.
• Format: Article
• Language: English
• Subjects: Corrosion resistance; Crystal structure; Deuteration; Deuterium; Heat treatment; High resolution; High temperature; High temperature hydrogen loading; Hydrogen induced degradation; Lattice parameters; Mechanical properties; Neutron diffraction; Phase stability; Phase transformation; Powder; Structural analysis; Zirconium; Zirconium hydride
• ISSN: 0022-3115; 1873-4820; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.01.008

Deuteride phases in the zirconium-deuterium system in the temperature range 25–286 °C have been studied in-situ by high resolution neutron diffraction. The study primarily focused on observations of δ→γ transformation at 180 °C, and the peritectoid reaction α + δ ↔ γ at 255 °C in commercial grade Zr powder that was deuterated to a deuterium/Zr ratio of one to one. A detailed description of the zirconium deuteride preparation route by high temperature gas loading is also described. The lattice parameters of α-Zr, δ-ZrDx and ε-ZrDx were determined by whole pattern crystal structure analysis, using Rietveld and Pawley refinements, and are in good agreement with values reported in the literature. The controversial γ-hydride phase was observed both in-situ and ex-situ in deuterated Zr powder after a heat treatment at 286 °C and slow cooling. •Controversial γ phase observed both in-situ and ex-situ after heat treatments.•γ-ZrD is observed at room temperature after 5 h of heat treatment at 286 °C.•Presence of α + δ ↔ γ at 255 °C was not observed.•It was observed that there is a δ → γ transformation present around 150 °C.