Structural evolution and dislocation behaviour during nano-rolling process of FCC metals: A molecular dynamics simulation based investigation

Though the structural properties of nanomaterials are significantly influenced by the rolling process, the deformation mechanism at an atomic level is unknown. In this study, molecular dynamics simulations have been applied to investigate the deformation mechanism and structural evolution of single crystal Al and Cu specimens during the room temperature nano-rolling process. Also, the effect of crystallographic orientation and stacking fault energy (SFE) on the nano-rolling behaviour is analyzed. Results from dislocation analysis show that all the Cu specimens have higher dislocation densities when compared with that of the Al specimens. This is attributed to lower SFE of Cu specimens that exhibit a limited recovery process and affect the dislocation mobility causing higher dislocation densities. This phenomenon is also confirmed through atomic strain analysis which has shown a higher volume fraction of slip bands in the Cube oriented Cu specimen when compared with the Cube oriented Al specimen. On the other hand, Brass- and Copper-oriented Al and Cu specimens show strain imbalance between the lower and upper sections of the specimen due to the different slip mechanism, which causes a lag between the movement of both sections and consequent bending of the specimen.