Formation of dislocation structures during cyclic deformation in near-[001] multiple-slip-oriented copper single crystals

Abstract

Dislocation structures in [001]-oriented copper single crystals have historically been studied at relatively low plastic shear strain amplitudes (γpl). Herein, the dislocation structure is investigated across a wide γpl range of 1.7 ∙ 10−4–1.7 ∙ 10−2. When γpl < 1.5 ∙ 10−2, the dislocation structure comprised a labyrinth with a set of parallel (100) and (001) walls. However, as γpl approached 1.5 ∙ 10−2, the dislocation structure changed to a cell structure to accommodate the higher plastic strain. The formation plane of the cell boundary depends on which slip system is activated as the primary slip system.