Mechanism of vibration on plastic deformation behavior of aluminum: A molecular dynamics simulation

Abstract

The superimposed vibration during plastic deformation of the metal can improve its formability. To explain the mechanism of the vibration, it is essential to deeply understand the transient evolution of the microstructure in this process. The molecular dynamics simulation was carried out to investigate the plastic deformation behavior of pure aluminum during uniaxial tensile and compressive deformation under vibration assistance. The kinetic energy of atoms, phase transition and the evolution distribution of dislocation, as well as the macroscopic mechanical behavior were analyzed. The results show that, vibration reduces the flow stress by inhibiting the production of hard-to-move dislocations. It hinders the tendency of dislocation entanglement and accelerates the dislocation annihilation. In addition, the deformation twins are generated during the compressive deformation, limiting the propagation of the vibrational energy. The superimposed vibration causes the aluminum to be softened during the tensile deformation and be hardened during the compressive deformation.