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 gamma(pl) = 8.0 x 10(-5)-7.0 x 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) over bar 39], [011] and [(4) over bar 5 9] silver single crystals; (2) a labyrinth is the main dislocation structure in the [(1) over bar 818] silver single crystal at high strain amplitudes; (3) vein and cell structures form in the [(2) over bar 33] silver single crystal at low and high strain amplitudes, respectively; (4) interaction between the primary and secondary PSBs arises in the [(1) over bar 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, [001] and [(1) over bar 11] regions. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.