Peculiarities of the development of plastic deformation in a textured FeNi alloy with a gradient grain structure

The mechanisms of nucleation and development of plastic deformation in the FeNi alloy with a gradient grain structure with a pronounced axial texture were revealed. The study was carried out on the basis of a molecular dynamics method. The simulated sample contained four layers, each of which consisted of grains of approximately the same size. The sample was subjected to uniform uniaxial tension at a constant rate in the direction of the grain misorientation axis. It was found that initially plastic deformation develops only in the layer with the largest grains and represents an abrupt growth of stacking faults. This process ends with the hardening of the deformed sample. At higher deformations, smaller grains contribute to the development of plasticity. At the same time, an almost ideal crystal structure can be restored in large grains, and twinning occurs in medium-sized ones.