Plasticity without dislocations in a polycrystalline intermetallic

• DOI: 10.1038/s41467-019-11505-1
• Publication Date: 2019-08-09T10:02:38Z
• Authors: Hubin Luo; Hongwei Sheng; Hongliang Zhang; Fengqing Wang; Jinkui Fan; Juan Du; J. Ping Liu; Izabela Szlufarska
• Keywords: Brittleness; Grain boundary strengthening; Ductility (Earth science); Deformation mechanism

Abstract Dislocation activity is critical to ductility and the mechanical strength of metals. Dislocations are primary drivers plastic deformation, their interactions with each other microstructural features such as grain boundaries (GBs) lead strengthening In general, suppressing dislocation leads brittleness polycrystalline materials. Here, we find an intermetallic that can accommodate large strain without help dislocations. For small sizes, deformation mechanism GB sliding, whereas for larger sizes material deforms by direct amorphization along shear planes. The unusual mechanisms absence traditional Hall-Petch (HP) relation commonly observed in metals extended regime weakening refinement, referred inverse HP relation. results first predicted simulations then confirmed experimentally.