Mass transfer and morphology change via dislocation emission in a macroporous FCC metal

• Published in: Materials letters 2019-07, Vol.247, p.67-70
• Main Authors: Cui, Yi, Chen, Zengtao, Ju, Yang
• Format: Article
• Language: English
• Subjects: Clustering effect; Computer simulation; Dislocation emission; Emission; FCC metals; Ligaments; Mass transfer; Materials science; Molecular dynamics simulation; Morphology; Scaling laws; Strain rate; Void growth
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2019.03.094

[Display omitted] •In a first effort, dislocation structure and mass transfer of a macroporous metal is studied.•The mass transfer is due to emitted multiple shear loops.•The critical stress for dislocation emission is in good agreement with the Lubarda model.•The critical stress of void with a short ILD is found insensitive to strain rate. In a first effort, the dislocation structure and related mass transfer in a macroporous FCC metal is studied via atomistic simulation. The interaction between the void and its periodic image has been intense ever since the onset of dislocation emission. The accumulated mass transfer is due to the emission of multiple shear loops, which shapes the morphology of the macroporous metal. The removal of mass from the intervoid ligament triggers its breakdown, connecting the voids. The strengthening of intervoid interaction is shown by running multiple cases with atom count ranging from 7.1 million to 95.4 million. The critical stress for dislocation emission versus the size of void is in a good agreement to the Lubarda model adjusted by the Gibson-Ashby scaling law. Nevertheless, the critical stress of void with a short intervoid ligament distance (ILD) demonstrates a surprisingly insensitivity of strain rate compared with the void that can be deemed standalone.