The Influence of Temperature and Strain Rate on the Mechanical Behavior in Uranium

The effect of temperature and strain rate on the deformation behavior of -uranium was investigated in the temperature ranged 300 to 55 by strain, rate change test. Strain rate sensitivity, activation volume, strain rate sensitivity exponent and dislocation velocity exponent were determined. The strain rate sensitivity exponent and dislocation velocity exponent were determined. The strain rate sensitivity exponent increases with strain below 40, while the exponent decreases with strain above 50. It is believed that the increase of strain rate sensitivity exponent with strain below 40 can be attributed to an increase in internal stress as a result of work hardening while decrease of the exponent with strain above 50 is due to predominance of thermal softening over work hardening because more slip, system are active in deformation above about 50.