Structural phase stability in nanocrystalline titanium to 161 GPa
Nanocrystalline titanium (nc-Ti) metal was investigated up to 161 GPa at room temperature using a diamond anvil cell. X-ray diffraction and electrical resistance techniques were used to investigate the compressibility and structural phase stability. nc-Ti is observed to undergo three structural phase transitions at high pressures, starting with α → ω at 10GPa and followed by ω → γ at 127GPa and γ → δ at 140GPa. The observed structural phase transitions, as well as compressibility, are consistent with previously reported values for coarse grained Ti (c-Ti). The high pressure experiments on nc-Ti samples do no show any significant variation of the α → ω transition pressure under varying nonhydrostatic conditions. This is in sharp contrast to c-Ti, where a significant decrease in the α → ω transition pressure is observed under increasing nonhydrostatic conditions. As a result, this would indicate that the decrease in grain size in nano grained titanium makes the α → ω phase transition less sensitive to shear stresses as compared to bulk or c-Ti.
- Research Organization:
- Univ. of Alabama, Birmingham, AL (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-06NA25396; NA0002014
- OSTI ID:
- 1342435
- Alternate ID(s):
- OSTI ID: 1251166
- Journal Information:
- Materials Research Express (Online), Journal Name: Materials Research Express (Online) Vol. 1 Journal Issue: 3; ISSN 2053-1591
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
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