Tensile orientation dependence of surface-roughness evolution in cyclically deformed Fe–30%Cr alloy single crystals

In order to investigate orientation dependence of surface roughness evolution, cyclic deformation tests have been carried out in Fe–30%Cr alloy single crystals having the tensile axes of [233], [122], [011] and [001]. Formation of persistent slip bands (PSBs) characterized by the surface roughness was observed in all the orientations. Atomic force microscope (AFM) observations revealed that the maximum heights of the PSB extrusions in the single-slip-oriented specimens ([233] and [122]) were larger than those of the [011] and [001] specimens by a factor of 7.5 and 15, respectively.