Characterization of dislocation microstructures in cyclically deformed [001] copper single crystals using high voltage scanning transmission electron microscopy

摘要

Low-cycle fatigue tests of copper single crystals with the [001] stress axis were performed at room temperature under constant plastic shear strain amplitudes between gamma(pl) = 3.5 x 10(-4) and 1.0 x 10(-2). Characteristic dislocation structures, which are highly dependent on a given plastic strain amplitude, were observed by high voltage scanning transmission electron microscopy. A vein-like dislocation structure, having a parallelepiped shape with two longitudinal (100) and (001) sides, was periodically formed along the [010] direction at around gamma(pl) = 1.0 x 10(-3). Labyrinth structure with the (100) and (001) dislocation walls was then gradually developed with increasing plastic strain amplitude.