Dissipative dislocation tunnelling at finite temperatures

Abstract

A theory for thermally assisted dislocation tunnelling through the Peierls barrier is developed. The theory takes into account the influence of dissipation on the underbarrier motion and describes the temperature and stress dependences of kink pair formation for any values of dislocation viscosity. Macroscopic plastic deformation parameters such as the flow stress and the stran-rate sensitivity are calculated and compared with the experimental data on low-temperature plastic deformation of lithium hydride.