Crystallite

Chemistry

Metallurgy

Materials science

Deformation (meteorology)

Tilt (camera)

Atomic units

Composite material

Geometry

Physics

Atom (system on chip)

Crystallography

Grain Boundary Sliding

Mathematics

Plane (geometry)

Quantum mechanics

Computer science

Grain boundary

Condensed matter physics

Embedded system

Microstructure

Science

Grain boundaries (GBs) play an important role in the mechanical behavior of polycrystalline materials. Despite decades of investigation, the atomic-scale dynamic processes of GB deformation remain elusive, particularly for the GBs in polycrystals, which are commonly of the asymmetric and general type. We conducted an in situ atomic-resolution study to reveal how sliding-dominant deformation is accomplished at general tilt GBs in platinum bicrystals. We observed either direct atomic-scale sliding along the GB or sliding with atom transfer across the boundary plane. The latter sliding process was mediated by movements of disconnections that enabled the transport of GB atoms, leading to a previously unrecognized mode of coupled GB sliding and atomic plane transfer. These results enable an atomic-scale understanding of how general GBs slide in polycrystalline materials.

Tracking the sliding of grain boundaries at the atomic scale