Effect of particle size on low temperature softening of work hardened Cu-SiO 2 crystals

Abstract

The low temperature softening of work hardened Cu-SiO 2, crystals has been studied. It has been found that the particle size and temperature dependences of the softening are determined by the magnitude of exp( −Q kT ) divided by the fourth power of the particle size, with the activation energy of 0.55–0.58 eV. The calculation based on the model that the Orowan loops disappear by the dislocation pipe diffusion satisfactorily explains the observed particle size and temperature dependences of the softening. The annealing also produces the specimen shape change, which occurs concurrently with the softening.