Strengthening mechanism and plasticity deformation of crystalline/amorphous Cu/CuTa nanomultilayer

Abstract Through the tensioning process using molecular dynamics simulation method, the mechanistic properties of the Cu/CuTa crystalline/amorphous nanomultilayers (CANMs) are explored. In the Cu layers, the phase transition from FCC to HCP occurs. The embryonic shear bands (ESBs) essentially appear from the crossing positions of the stacking faults and interfaces, after that, grow to establish the shear transformation zones (STZs). The great shear strain atoms concentrate into the diagonal strips that create with the horizontal direction an angle of 45°. The Cu/CuTa CANMs with more layers are more easily damaged. For the cases with the different w2 values, the f0.3 value reduces with the increase of the w2 value. The tensile strength increases with the w2 increases and the inverse Hall-Petch relation is observed. For the Cu/Cu10Ta90, Cu/Cu25Ta75, and Cu/Cu90Ta10 CANMs, the shrinkages are explicit, the formation of the STZs is more obvious than that in the Cu/Cu50Ta50, Cu/Cu75Ta25 specimen.