In-situ observation of an irradiation creep deformation mechanism in zirconium alloys

M. Gaumé (1) , P. Baldo (2) , Frédéric Mompiou (3) , F. Onimus (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 ANL - Argonne National Laboratory [Lemont]
3 CEMES-PPM - Physique de la Plasticité et Métallurgie

We report an original experimental study on a zirconium alloy deformed in situ under ion irradiation and applied stress inside a Transmission Electron Microscope. We observe that dislocations initially pinned on irradiation de- fects can be unpinned and glide at a lower stress under the effect of the irradiation. It is proposed that unpinning occurs by a local effect of the displacement cascade created by the incoming ion in the vicinity of the pinning point. This novel mechanism of dislocation glide assisted by irradiation is thought to play a crucial role on in- reactor irradiation creep of zirconium alloys.

Domaines: Mécanique des matériaux [physics.class-ph]; Science des matériaux [cond-mat.mtrl-sci]

M. Gaumé, P. Baldo, Frédéric Mompiou, F. Onimus. In-situ observation of an irradiation creep deformation mechanism in zirconium alloys. Scripta Materialia, 2018, 154, pp.87 - 91. ⟨10.1016/j.scriptamat.2018.05.030⟩. ⟨hal-01811926⟩