Abstract
An equiatomic VCoNi medium-entropy alloy possesses high sensitivity to grain-boundary strengthening, achieved by severe lattice distortions. Its ultrafine-grain structure enables 1.5 Gigapascal yield strength even for the fully recrystallized alloy with a single face-centered cubic structure. The high density of grain boundaries also generates high back stresses via piling up of massive dislocations, and the low cross-slip probabilities produce not only robust dislocation-mediated plasticity but also high back stress contribution to flow stress, which affords high strain-hardening capability to ultrafine-grain alloys, with 1.7 Gigapascal ultimate tensile strength with remarkable ductility. Our approach provides a new method for developing ultrastrong metallic materials.
Original language | English |
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Pages (from-to) | 315-321 |
Number of pages | 7 |
Journal | Materials Research Letters |
Volume | 9 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- Medium-entropy alloy
- grain boundary strengthening
- severe lattice distortion
- severe plastic deformation
- ultrafine grain structure
ASJC Scopus subject areas
- Materials Science(all)