Header menu link for other important links
X
Anomalous mechanical behavior of nanocrystalline binary alloys under extreme conditions
Published in Nature Publishing Group
2018
PMID: 30002376
Volume: 9
   
Issue: 1
Abstract
Fundamentally, material flow stress increases exponentially at deformation rates exceeding, typically, ~103 s-1, resulting in brittle failure. The origin of such behavior derives from the dislocation motion causing non-Arrhenius deformation at higher strain rates due to drag forces from phonon interactions. Here, we discover that this assumption is prevented from manifesting when microstructural length is stabilized at an extremely fine size (nanoscale regime). This divergent strain-rate-insensitive behavior is attributed to a unique microstructure that alters the average dislocation velocity, and distance traveled, preventing/delaying dislocation interaction with phonons until higher strain rates than observed in known systems; thus enabling constant flow-stress response even at extreme conditions. Previously, these extreme loading conditions were unattainable in nanocrystalline materials due to thermal and mechanical instability of their microstructures; thus, these anomalies have never been observed in any other material. Finally, the unique stability leads to high-temperature strength maintained up to 80% of the melting point (~1356 K). © 2018 The Author(s).
About the journal
JournalNature Communications
PublisherNature Publishing Group
ISSN20411723
Open AccessYes
Concepts (26)
  •  related image
    Alloy
  •  related image
    Crystallin
  •  related image
    Cuprous ion
  •  related image
    Nanocrystal
  •  related image
    Nanocrystalline
  •  related image
    Nanomaterial
  •  related image
    Unclassified drug
  •  related image
    BRITTLE FAILURE
  •  related image
    High temperature
  •  related image
    Mechanical property
  •  related image
    Microstructure
  •  related image
    Strain rate
  •  related image
    Article
  •  related image
    Chemical structure
  •  related image
    Energy
  •  related image
    EXTREME ENVIRONMENT
  •  related image
    High resolution transmission electron microscopy
  •  related image
    Mechanics
  •  related image
    Molecular dynamics
  •  related image
    Nanotechnology
  •  related image
    Phonon
  •  related image
    Quantum mechanics
  •  related image
    Steady state
  •  related image
    Stress
  •  related image
    Temperature
  •  related image
    Temperature dependence