Effect of component crystal orientations on the cyclic stress–strain behavior of copper bicrystals

Cyclic stress–strain curves (CSSCs) of some copper bicrystals with a grain boundary (GB) perpendicular to the stress axis were compared. It was found that the component crystal orientations played a decisive effect on the CSSCs of these bicrystals. The CSSC of [5̄913]⊥[5̄79] copper bicrystal with two single slip oriented component crystals exhibited two plateau regions in the lower and higher plastic strain range, respectively. For [1̄23]⊥[3̄35] and [3̄45]⊥[1̄17] copper bicrystals, both with one single slip and one double slip oriented component crystals, the corresponding CSSCs only displayed one plateau region or pseudo-plateau region in the low and intermediate plastic strain range, respectively. However, the [1̄34]⊥[1̄34] copper bicrystal with the same single-slip-oriented component crystal showed one plateau region over a wide plastic strain range in its CSSC, which was somewhat similar to the result for copper single crystal oriented for single-slip. In this paper, the effect of the component crystal orientations on the CSSCs of these copper bicrystals is discussed.