Irradiation in BCC materials: Defect-induced changes of the effective dislocation mobility and their relation with the dose-dependent fracture response

Singh Kulbir (1) , Christian Robertson (2) , A.K. Bhaduri (1)

1 Indira Gandhi Centre for Atomic Research
2 LC2M - Laboratoire d'Etude du Comportement Mécanique des Matériaux

The mechanical response of nuclear structural materials and their lifetime are strongly affected by radiation effects. This influence is of concern, especially in body centered cubic (BCC) materials, which exhibiting a well-defined ductile to brittle transition. The ductile to brittle transition temperature (DBTT) itself is dose-dependent and may rise to or above the room temperature. In current work, the irradiation effect is modeled to predict the dose-dependent changes of the effective dislocation mobility, represented by the Defect Induced Apparent Temperature Shift (DDIAT). Mainly dislocation based crystal plasticity material model is used rather than a phenomenological approach. This material model accounts for both thermally activated dislocation mobility and dislocation mobility in an athermal regime of BCC materials. The defect-induced evolution of DDIAT in turn analyzed and their relations with the fracture response are highlighted and discussed.

Keywords: Crystal plasticity; Dislocation mobility; Irradiation hardening; Strain localization

Domains: Chemical Sciences; Material chemistry

Singh Kulbir, Christian Robertson, A.K. Bhaduri. Irradiation in BCC materials: Defect-induced changes of the effective dislocation mobility and their relation with the dose-dependent fracture response. Progress in Nuclear Energy, 2021, 141 (141), pp.103926. ⟨10.1016/j.pnucene.2021.103926⟩. ⟨cea-03601054⟩