| Abstract Scope |
Metallic materials can fail under extreme environments due to inadequate strength and corrosion resistance. Metals can be either crystalline (soft but ductile) or amorphous (strong but brittle). Nanocrystalline metals are strong but poor ductility, while nanosized amorphous structures could enhance ductility by suppressing localized shear bands. Therefore, a new strategy: crystalline-amorphous nanostructured metals, is proposed to combine the advantages of both structures by encapsulating nanograins within thick amorphous grain boundaries. This unique co-deformation cooperative strengthening effect can result in exceptional strength-ductility synergy. Furthermore, the amorphous phase reduces the risk of localized or galvanic corrosion, enhancing anticorrosive behavior. Mainly through in-situ SEM micro-pillar testing, corrosion properties assessment, atomic characterizations, atomistic simulations, and theoretical modeling, we investigate the plastic deformation and corrosion mechanisms of ultra-strong and corrosion-resistant crystalline-amorphous nanostructured metals. This research was supported by Hong Kong Research Grants Council (Nos. 15210123 and 15201424), GDSTC (No. 2024A1515010781), and PolyU grant (No. 1-CD9D). |