Atomistic simulation of interactions between an edge dislocation and Cu precipitates with different chemical compositions in α-Fe
Abstract
In this work the interactions of an edge dislocation with Cu precipitates of different diameters in α-Fe were investigated by molecular dynamics simulation. The influence of Fe atoms or outer Ni shell on the interactions was also studied. It is found that the dislocation stress field assists a structure transformation of the precipitates from BCC to FCC/HCP during the gliding of the dislocation. For the Cu precipitates with diameters less than 4 nm, most of the atoms return to BCC structure after the dislocation leaves away. The structure transformation of Cu-Fe precipitates is identical with pure Cu precipitates with diameters less than 4 nm. The outer Ni shells contribute the precipitate transformation to FCC/HCP structure and reduce the critical diameter of structure transformation. The critical resolved shear stress (CRSS) has been calculated for the precipitates and it is demonstrated that the FCC/HCP fraction of the precipitate contributes to the CRSS in this interaction.
- Publication:
-
Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- November 2019
- DOI:
- 10.1016/j.nimb.2019.07.044
- Bibcode:
- 2019NIMPB.458...39Y
- Keywords:
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- Dislocation;
- α-Fe;
- Cu precipitates;
- Compositions;
- Structure transformation