Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1624393 | Journal of Alloys and Compounds | 2008 | 5 Pages |
Abstract
The structural relationship between the hydride phases in Ti-Mo-H solid solution system (Mo content up to 15 at% in the alloy) during dehydrogenation process under annealing has been studied by conventional and in situ X-ray powder diffraction and transmission electron microscopy (TEM) analysis. During dehydrogenation, the saturated hydrides of the Ti-Mo alloys with fcc δ-phase structure transfer into bcc β-phase at higher temperatures. An associated hydrogen concentration reduction for the δ-phase hydride is observed in the process. However, as the hydrogen concentrations decrease to certain values (H/M â¼Â 1.1-1.7), the unsaturated δ-phase formed at high temperature would become unstable at lower temperature, and transfer into a tetragonal phase (denoted the É-phase here). Unlike that of the É-phase in Ti-H system, the phase transition does not occur for the saturated δ-phase with hydrogen concentration close to the stoichiometric limit. The hydrogen concentration of this É-phase hydride is in between that of the tetragonal γ and É-phase in Ti-H system, but more close to the γ-phase. The occurrence region of this É-phase expands along with the increase of the Mo content in the alloys. The phase has a lattice similar to that of the É-phase in Ti-H system with corresponding fct unit-cell c/a < 1.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Erdong Wu, Xu Xu, Xuezhong Yuan, Xiumei Guo, Sucheng Wang,