Preferred hydride growth orientation of U―0.79 wt.%Ti alloy with β+U2Ti microstructure

• Published in: Journal of nuclear materials Vol. 441; no. 1-3; pp. 1 - 5
• Main Authors: Shi, Peng, Shen, Liang, Bai, Bin, Lang, Dingmu, Lu, Lei, Li, Gan, Lai, Xinchun, Zhang, Pengcheng, Wang, Xiaolin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.10.2013
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Hydrides; Hydrogen storage; Installations for energy generation and conversion: thermal and electrical energy; Microstructure; Nuclear fuels; Nucleation; Oxides; Scanning electron microscopy; Texture; Uranium base alloys; Electron microscope; Oxide layer; Hydrogen; Laser; Diffusion barrier; Oxides; Hydrides; Microstructure; Texture; Nuclear reactor
• ISSN: 0022-3115
• DOI: 10.1016/j.jnucmat.2013.05.005

The nucleation and propagation during the early stage of the hydriding of U-0.79 wt.%Ti were investigated in order to ascertain the influence of texture and microstructure on hydride initiation and growth. Several samples of the so-called " beta +U2Ti" microstructure were prepared in a specially designed manner. The topographical characteristics of the post-hydrided sample surface were collected via laser confocal microscope and Scanning Electron Microscope (SEM). Good correlation was found between the strip-type hydride and the underlying metal matrix. The discontinuities in the oxide layer and the differences in thickness, composition and structure of the oxide on alpha -U and U2Ti may influence the hydrogen diffusion through the oxide barrier. The difference of hydriding reaction tendency and durability against hydride powdering between alpha -phase and U2Ti were proposed to account for the anisotropic hydride growth, which resulted in the strip-type hydride. The results suggest that the metal properties, including microstructure, inclusions and affinity toward hydrogen, is the dominants of nucleation sites.