Orientation dependence of surface relief topography in fatigued copper single crystals

Surface relief of cylindrical copper single crystals oriented for single slip and cyclically strained in plastic strain control up to fracture was studied using a scanning electron microscope (SEM) and interference light microscope. Both individual persistent slip bands (PSBs) and macrobands were observed. Their length, width and height were evaluated in dependence on the position on the specimen. The macroband height was found to be a periodic function of the position along the specimen circumference with a period of 180 °. In the surface line where the primary Burgers vector is a tangent to the specimen surface even the negative protrusions were observed and the average macroband height was approximately zero. The maximum macroband height was observed at the surface line resulting from the intersection of the surface with the plane parallel to the primary Burgers vector and passing through the specimen axis.