Molecular dynamic study on the deformation mechanism based on strain rate, solute atomic concentration and temperature in dual-phase equiaxial nanocrystalline AgCu alloy

Abstract

Nanocrystalline (NC) AgCu alloys have been attracted significant attention because of excellent electrical and mechanical properties. The microstructural evolution and deformation mechanisms are still challenging issues, and it is hard to observe directly by experimental methods. Accordingly, in this paper, atomic simulations are performed to investigate the tensile behavior of dual-phase equiaxial NC AgCu alloy (DPEA) at different strain rate (104-107 s−1), solute atomic concentration (5–20%) and temperature (300–600 K) using embedded atom method (EAM) potential. Relevant stress-strain curves and yield stress have been obtained. Result analysis reveals dislocation motion, atomic diffusion and grain boundary (GB) sliding are dominating deformation mechanisms. With the increase of strain rate and deformation, main deformation mechanisms are discovered to change from dislocation motion to GB sliding. Furthermore, the increase of solute atomic concentration (SAC) and temperature will promote the atomic diffusion and GB sliding. This work explains evolution process on deformation mechanisms of DPEA. It provides a qualitative analysis to design excellent mechanism property of DPEA by means of optimizing material structure parameters.