Orientation-related twinning and dislocation glide in a Cantor High Entropy Alloy at room and cryogenic temperature studied by in situ TEM straining

Daniela Oliveros , Anna Fraczkiewicz (1, 2) , Antonin Dlouhy , Chen Zhang , Hengxu Song , Stefan Sandfeld , Marc Legros (3, 4)

1 LGF-ENSMSE - Laboratoire Georges Friedel
2 Mines Saint-Étienne MSE - École des Mines de Saint-Étienne
3 CEMES - Centre d'élaboration de matériaux et d'études structurales
4 CEMES-PPM - Physique de la Plasticité et Métallurgie

In situ straining experiments were performed in a TEM on an equimolar CoCrFeMnNi (Cantor) high entropy alloy at room and cryogenic temperature. Perfect and partial dislocation activity were recorded in both cases. Twinning directly follows the development of partial dislocation shearing that has various origins (perfect dislocation splitting, anchoring). It is shown that, although twinning is more frequently observed at liquid nitrogen temperature, its prevalence depends mainly on crystal orientation. As a result, twinning and perfect dislocation plasticity are likely to occur jointly in random oriented polycrystals, even at early stages of deformation.

Mots clés: In situ TEM; High Entropy Alloy; Plasticity; Twinning; Dislocation

Domaines: Mécanique des matériaux [physics.class-ph]; Cristallographie; Mécanique des solides [physics.class-ph]; Matériaux; Science des matériaux [cond-mat.mtrl-sci]; Mécanique des matériaux [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des solides [physics.class-ph]; Mécanique des structures [physics.class-ph]; Matériaux; Génie mécanique [physics.class-ph]

Daniela Oliveros, Anna Fraczkiewicz, Antonin Dlouhy, Chen Zhang, Hengxu Song, et al.. Orientation-related twinning and dislocation glide in a Cantor High Entropy Alloy at room and cryogenic temperature studied by in situ TEM straining. Materials Chemistry and Physics, 2021, 272, pp.124955. ⟨10.1016/j.matchemphys.2021.124955⟩. ⟨hal-03323290⟩