Diffusion-driving interface void closure: a universal atomic scale framework
File(s)
Accepted version
Author(s)
Jiang, Jun
Wang, Hao
Type
Journal Article
Abstract
The elimination of interface voids is a fundamental process in solid-state materials joining and interface engineering, yet the atomic-scale diffusion mechanisms that
govern its progression remain unresolved. Continuum mechanics models capture only the macroscopic void evolution and cannot resolve the heterogeneous atomic
transport or local chemistry evolution that govern closure at the atomic scale. Here we reveal the elementary atomic events around voids and introduce a scalar closure index
H that is independent of initial void geometry to demonstrate the universal three-stage void closure framework: curvature-driven fast rounding, necking-assisted partition and uniform shrinkage, and a slowly shrinking terminal regime. We observed an interface
atom flux 3 times that of bulk atoms demonstrates that the transport pathway dominating void closure. Ni preferentially segregates to void-surface sites through a
convergence of thermodynamic affinity for low-coordination environments and the highest atomic mobility, emerging as the principal elemental driver of closure kinetics in the Fe-Ni-Cr system. This element-selective mechanism and the universal closure framework together elevate the design of void closure conditions from empirical trial and-error to mechanistic insight across diverse solid-state systems.
govern its progression remain unresolved. Continuum mechanics models capture only the macroscopic void evolution and cannot resolve the heterogeneous atomic
transport or local chemistry evolution that govern closure at the atomic scale. Here we reveal the elementary atomic events around voids and introduce a scalar closure index
H that is independent of initial void geometry to demonstrate the universal three-stage void closure framework: curvature-driven fast rounding, necking-assisted partition and uniform shrinkage, and a slowly shrinking terminal regime. We observed an interface
atom flux 3 times that of bulk atoms demonstrates that the transport pathway dominating void closure. Ni preferentially segregates to void-surface sites through a
convergence of thermodynamic affinity for low-coordination environments and the highest atomic mobility, emerging as the principal elemental driver of closure kinetics in the Fe-Ni-Cr system. This element-selective mechanism and the universal closure framework together elevate the design of void closure conditions from empirical trial and-error to mechanistic insight across diverse solid-state systems.
Date Acceptance
2026-09-25
Citation
Nature Communications
ISSN
2041-1723
Publisher
Nature Portfolio
Journal / Book Title
Nature Communications
Copyright Statement
Copyright This paper is embargoed until publication. Once published the author’s accepted manuscript will be made available under a CC-BY License in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy).
License URL
Publication Status
Accepted