First-Principles Study of Secondary Slip in Zirconium

Nermine Chaari (1) , Emmanuel Clouet (1) , David Rodney (2)

1 SRMP - Service de recherches de métallurgie physique
2 ILM - Institut Lumière Matière [Villeurbanne]

Although the favored glide planes in hexagonal close-packed Zr are prismatic, screw dislocations can escape their habit plane to glide in either pyramidal or basal planes. Using abinitio calculations within the nudged elastic band method, we show that, surprisingly, both events share the same thermally activated process with an unusual conservative motion of the prismatic stacking fault perpendicularly to itself. Halfway through the migration, the screw dislocation adopts a nonplanar metastable configuration with stacking faults in adjacent prismatic planes joined by a two-layer pyramidal twin.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Nermine Chaari, Emmanuel Clouet, David Rodney. First-Principles Study of Secondary Slip in Zirconium. Physical Review Letters, 2014, 112, pp.075504. ⟨10.1103/PhysRevLett.112.075504⟩. ⟨hal-00950867⟩