Slip band growth and dislocation velocities in thin flat crystals of n-irradiated Cu and Cu-30% Zn

Extending earlier work (POTTHOFF ) the dependence of the arrangement and development of slip bands on the thickness of thin flat single crystals of neutron-irradiated copper and Cu-30% Zn orientated for singe glide is studied at room temperature. Distinct differences in the behaviour of thin (20 … 200 μm thickness) and thick (≧ 500 μm thickness) crystals are found. Partly they are connected with the bending stresses in the region of the Lüders band front. The velocities of dislocation groups in the first stages of slip band growth are estimated. The deformation kinetics is discussed in the concepts of viscous glide and nucleation rate of dislocations for both materials.