Numerical simulation of the dynamic interactions between dislocation and solute atoms

Abstract

Using the Cottrell-Bilby kinetics model for solute atoms, evolution of the solute concentration around dislocation line has been investigated with respect to the strain rate. Three types of interactions between dislocation and solutes were obtained: At low strain rates, the dislocation is effectively pinned by its condensed solute cloud and the solute concentration remains almost at its saturation value. At high strain rates, the npinning effect predominates and dislocation moves at high velocity with little solute disturbance. While at the intermediate strain rates, the aging and unpinning effects take place alternately and dynamic strain ageing operates. Morevover, the N-shaped relationship between the rate-dependent flow stress and strain rate has also been naturally deduced from the model equations without additional assumptions.