Λεπτομέρειες βιβλιογραφικής εγγραφής
| Τίτλος: |
Low-stress activation of plasticity at various twist grain boundaries in nanocrystalline aluminum: an atomistic study. |
| Συγγραφείς: |
Manukhina, K. D.1 (AUTHOR), Mayer, A. E.1 (AUTHOR), Krasnikov, V. S.1 (AUTHOR) vas.krasnikov@gmail.com |
| Πηγή: |
Journal of Materials Science. Aug2026, Vol. 61 Issue 29, p21116-21128. 13p. |
| Θεματικοί όροι: |
*Crystal grain boundaries, *Material plasticity, *Crystallinity, *Dislocations in crystals, *Shear (Mechanics), *Molecular dynamics |
| Περίληψη: |
This work provides atomistic-scale observations that twist GBs act as low-stress plasticity sources. MD simulations of shear deformation in aluminum demonstrate that metastable twist GBs activate plastic sliding at remarkably low stresses, in contrast to tilt GBs. Plastic relaxation proceeds via two distinct mechanisms: LAGBs and IAGBs slide via conservative glide of intrinsic GB dislocations, while HAGBs deform through localized amorphization. GBs deforming by amorphization suppress high local stress, inhibiting subsequent dislocation emission. This suppression, coupled with hardening from grain rotation, allows such systems to reach exceptional flow stresses (> 1300 MPa). Existence of low-stress activation of twist GBs offers a plausible mechanism to reconcile macroscopic flow stress of nanocrystalline metals with Hall–Petch prediction. GB type, specifically the propensity of twist GBs to amorphize, is a key factor controlling strength. [ABSTRACT FROM AUTHOR] |
| Βάση Δεδομένων: |
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