Details

Autor(en) / Beteiligte

• Chaari, Nermine
• Rodney, David
• Clouet, Emmanuel

Titel

Oxygen - Dislocation interaction in zirconium from first principles

Ist Teil von

• Acta materialia, 2017-06, Vol.132, p.416-424

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Plasticity in zirconium alloys is mainly controlled by the interaction of 1/3〈12¯10〉 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. [Display omitted]