Structural phase stability in group IV metals under static high pressure
- Los Alamos National Laboratory
- U OF ALABAMA AT BIRMINGHAM
In group IV metals (Ti, Zr, and Hf) room temperature compression leads to a martensitic transformation from a ductile {alpha} to a brittle {omega} phase. {alpha} {yields} {omega} phase boundary decreases to lower pressure at high temperature and can limit the use of group IV metals in industrial applications. There is a large discrepancy in the transition pressure reported in literature, with some of the variation attributed to experimental conditions (i.e. hydrostatic vs. non-hydrostatic). Shear deformation in non-hydrostatic experiments drives {alpha} {yields} {omega} transition and decreases transition pressure. Impurities can also aid or suppress {alpha} {yields} {omega} transition. By performing x-ray diffraction experiments on samples in a diamond anvil cell we show that interstitial impurities, such as C, N, and O can obstruct {alpha} {yields} {omega} transition and stabilize {alpha} phase to higher pressure. We also show that reduction in grain size can also influence {alpha} {yields} {omega} phase boundary and help stabilize {alpha} phase to higher pressure under non-hydrostatic conditions.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 992186
- Report Number(s):
- LA-UR-09-05052; LA-UR-09-5052; TRN: US201022%%173
- Resource Relation:
- Conference: APS Shock Compression of Condensed Matter 2009 ; June 28, 2009 ; Nashville, TN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Transitions of Dislocation Glide to Twinning and Shear Transformation in Shock-Deformed Tantalum
STRUCTURAL CONSIDERATIONS IN DEVELOPING REFRACTORY METAL ALLOYS