Atomistic Numerical Simulation on Nanoupsetting Process of Copper Brick

Abstract

Nanofabrication techniques such as nanoforging have been used to fabricate nanosize components in recent years. As a basic form of nanoforging process, nanoupsetting was studied in this paper via atomistic simulation. First a simplified computation model for upsetting process of single crystalline copper was created, and then the deformation mechanism was investigated at the atomic scale. The results show that the plastic deformation was initiated by the high‐level strain at the corners of the brick; partial dislocations nucleated at the corners and propagated along the [101] and [011] directions in the (111) plane; after unloading, the defects did not disappear or move out to the surface due to lattice friction; the computed load during nanoupsetting agrees well with the theoretical value. At last, the FEM simulation results for this single crystal were also shown, but no load drop was found in its load‐displacement curve, which indicates that atomistic simulation is more elaborate than crystal plasticity FEM for nanoscale forming problems.