Abstract
Unalloyed uranium and uranium-based U-0.75%Ti alloy were studied in
planar impact experiments with initial sample temperature ranged from
300 to 1050 K. The velocity of the samples free surface was monitored by
VISAR. It was found, with aid of the simple wave approximation, that the
flow stress of studied materials is composed of two parts: the
strain-rate independent part which stays constant up to the onset of
alpha-gamma transformation and drops almost four times in gamma-phase,
and the strain-rate dependent, viscous, part. The latter is
characterized by 20-fold decrease of the dynamic viscosity with heating
from room to transformation temperature. This decreased viscosity is
inherited unchanged by transformed gamma-phase. The spall strengths of
alpha-uranium decreases slightly, about 30%, with its heating towards
the transformation temperature and experiences two times drop entering
the gamma-phase. The transformation causes similar drop of the uranium
shear modulus while its bulk modulus undergoes only 10-% change.
| Original language | English |
|---|---|
| Title of host publication | American Physical Society, 14th APS Topical Conference on Shock Compression of Condensed Matter, July 31-August 5, 2005 |
| State | Published - 1 Jul 2005 |