The creep of thorium near room temperature

The rate of plastic deformation of thorium has been investigated as a function of stress and strain at temperatures from 0 to 60°C. The rate of creep or plastic deformation was found to depend on the instantaneous values of the stress, strain and temperature and thus could be expressed by a mechanical equation of state. The yield point phenomenon was observed even at the lowest plastic strain rates. A critical stress was found below which no plastic deformation was observed