Oxygen - Dislocation interaction in zirconium from first principles

Abstract

Plasticity in zirconium alloys is mainly controlled by the interaction of 1/3 1210 screw dislocations with oxygen atoms in interstitial octahedral sites of the hexagonal close-packed lattice. This process is studied here using ab initio calculations based on the density functional theory. The atomic simulations show that a strong repulsion exists only when the O atoms lie in the dislocation core and belong to the prismatic dislocation habit plane. This is a consequence of the destruction of the octahedral sites by the stacking fault arising from the dislocation dissociation. Because of the repulsion, the dislocation partially cross-slips to an adjacent prismatic plane, in agreement with experiments where the lattice friction on screw dislocations in Zr-O alloys has been attributed to the presence of jogs on the dislocations due to local cross-slip.

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Direct diffusion through interpenetrating networks: Oxygen in titanium
• Screw dislocation in zirconium: An ab initio study
• First-Principles Study of Secondary Slip in Zirconium
• First order pyramidal slip of 1/3 <1-210> screw dislocations in zirconium

Cited by in corpus (3)

• Oxygen-dislocation interaction in titanium from first principles
• Influence of simple metals on the stability of $⟨a⟩$ basal screw dislocations in hexagonal titanium alloys
• Secondary slip of screw dislocations in zirconium