Dislocation Networks and the Microstructural Origin of Strain Hardening.
Phys Rev Lett
; 121(8): 085501, 2018 Aug 24.
Article
em En
| MEDLINE
| ID: mdl-30192605
ABSTRACT
When metals plastically deform, the density of line defects called dislocations increases and the microstructure is continuously refined, leading to the strain hardening behavior. Using discrete dislocation dynamics simulations, we demonstrate the fundamental role of junction formation in connecting dislocation microstructure evolution and strain hardening in face-centered cubic (fcc) Cu. The dislocation network formed consists of line segments whose lengths closely follow an exponential distribution. This exponential distribution is a consequence of junction formation, which can be modeled as a one-dimensional Poisson process. According to the exponential distribution, two non-dimensional parameters control microstructure evolution, with the hardening rate dictated by the rate of stable junction formation. Among the types of junctions in fcc crystals, we find that glissile junctions make the dominant contribution to strain hardening.
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MEDLINE
Idioma:
En
Ano de publicação:
2018
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Article