Microstructural characteristics, atomic-scale features, and growth mechanisms of deuterides (hydrides) in hafnium

Abstract

Hafnium hydride is a promising material for next-generation nuclear reactors, particularly as control rods for fast fission and shielding in fusion systems. The material's intrinsic brittleness encourages its use in the form of hydride-metal composites, where the functional and mechanical performance is strongly influenced by the multiscale structure of hydride-matrix interfaces. In this study, we employ a suite of microscopy techniques, including scanning electron microscopy with electron backscatter diffraction, transmission electron microscopy with electron energy-loss spectroscopy, and atom probe tomography, to investigate the deuteride-matrix interfaces in a deuterium-charged Hf alloy. We characterise their structure and chemistry, extracting key information including the deuteride-matrix crystallographic orientation relationship, microstructural features, misfit-induced dislocation distributions, electron energy-loss characteristics, and the segregation of oxygen during deuteride growth. These findings help clarify the mechanisms of interface evolution and may contribute to improved understanding of hydride-metal systems, with potential relevance for their processing, performance, and design in nuclear applications.

arXiv comment23 pages, 9 figures. Published in Materials Characterization, DOI: https://doi.org/10.1016/j.matchar.2025.115904

References in corpus (5)

• Substitutional effects in TiFe for hydrogen storage: a comprehensive review
• Characterizing solute hydrogen and hydrides in pure and alloyed titanium at the atomic scale
• Resolving hydrogen atoms at metal-metal hydride interfaces
• Quantification challenges for atom probe tomography of hydrogen and deuterium in Zircaloy-4
• The effect of cooling rate and grain size on hydride formation in Zircaloy-4