Abstract
A (TiAl)Hx hydride which has a tetragonal crystal structure with lattice parameters a = 0.452 nm and c = 0.326 nm (c/a = 0.721) has been observed in Ti42Al, Ti45Al and Ti50Al (at.%) two-phase (Ti3Al (α2) + TiAl (γ)) titanium aluminides by cathodic charging in a 5% H2SO4 solution. Cracks or pits are also observed within the γ phase regions in the two-phase (α2 + γ) coexisting grains (such as lamellar grains) but not within the α2 phase or single γ grains. Weights of the samples decrease with increasing charging time owing to the crack or pit formation, and this is more drastic in the Ti-50Al alloy than in the Ti-42Al and Ti-45Al alloys. The hydride is thermally stable at temperatures up to about 550 K (277 °C) and dissociates completely at temperatures between 673 K (400 °C) and 723 K (450 °C).
Original language | English |
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Pages (from-to) | 1-6 |
Number of pages | 6 |
Journal | Journal of Alloys and Compounds |
Volume | 216 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1994 Dec |
Externally published | Yes |
Keywords
- Cathodic charging
- Hydride formation
- Titanium aluminides
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry