Formation of micro shear bands during cyclic deformation of sub-microcrystalline nickel

Cyclic deformation of sub-microcrystalline nickel at high plastic strain amplitude generated macro shear bands, causing fatal cracking. The macro shear bands consisted of several micro shear bands, each band containing a single layer of elliptical grains that appeared at less than 50° with respect to the loading axis. Micro texture investigations in micro shear bands revealed almost the same texture with similar shear values as in macro shear bands. During cyclic deformation local overlapping of evolving micro shear bands resulted in formation of fatal macro shear bands.