The deformation and dislocation microstructure of a [013] double-slip-oriented Cu single crystal under a symmetric tension–compression cyclic load were characterized at room temperature in open-air and a neutral 0.5M NaCl aqueous solution, respectively. The surface morphology of deformed specimens and the dislocation structures at saturation stage of cyclic deformation were observed using scanning electron microscopy by the electron channelling contrast technique and transmission electron microscopy. The results show that the saturation dislocation structures during the corrosion fatigue in the 0.5M NaCl aqueous solution mainly consist of labyrinth, wall and vein dislocation microstructures, as well as deformation twins, which differ from the wall and vein dislocation structures in open-air environment. More importantly, transmission electron microscopic observations were reported here that provided evidence of deformation twinning in the [013] double-slip-oriented Cu single crystal during corrosion fatigue at room temperature and a very slow strain rate, which was generally only observed at sub-ambient temperature and/or high strain rate conditions.

Environmental Effects on Deformation Mechanism and Dislocation Microstructure in Fatigued Copper Single Crystal. J.H.Yang, X.P.Zhang, Y.W.Mai, W.P.Jia, W.Ke: Materials Science and Engineering A, 2005, 396[1-2], 403-8