Effect of orientation on the cyclic deformation behavior of silver single crystals: Comparison with the behavior of copper and nickel single crystals

This paper reports and discusses the effects of orientation on the cyclic deformation behavior of typical face-centered cubic (fcc) copper, nickel and silver single crystals, including the cyclic stress–strain (CSS) curves and dislocation configurations. Firstly, the CSS curves of silver single crystals of different orientations showed a clear plateau region over the strain range γpl=8.0×10-5–7.0×10-3γpl=8.0×10-5–7.0×10-3, however, there were two saturation shear stresses of 18–21 and 25–26 MPa, corresponding to the lower and upper plateau, respectively. After that, the dislocation configurations from differently oriented silver single crystals are well summarized as follows: (1) persistent slip band (PSB) ladders or walls appear in [2¯39], [0 1 1] and [4¯59] silver single crystals; (2) a labyrinth is the main dislocation structure in the [1¯818] silver single crystal at high strain amplitudes; (3) vein and cell structures form in the [2¯33] silver single crystal at low and high strain amplitudes, respectively; (4) interaction between the primary and secondary PSBs arises in the [1¯414] silver single crystal. Finally, combined with the results of copper and nickel single crystals, it can be concluded that the effects of orientation on the cyclic deformation behavior of these three kinds of single crystals follow a general principle. That is the orientation-dependent dislocation configuration can be divided into three regions in the stereographic triangle, including the central, [0 0 1] and [1¯11] regions.