Domain 2: Plastic flow localization WP4/5 - General

1. Multiscale Modelling for Fusion and Fission Materials (M4F) 1st Plenary meting , CNRS, Paris, February 13-14, 2019 Domain 2: Plastic flow localization WP4/5 - General David Rodney (CNRS) and Ermile Gaganidze (KIT) • This project has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 755039

2. O. Anderoglu et al., MMT A (2013) Domain 2 - WP4 & WP5 Objective: Develop physically-based models to predict the mechanical behavior of irradiated F/M steels accounting slip localization Multiscale approach: Atomistic, dislocation dynamics, crystal plasticity, continuum mechanics simulations Experimental validation: Mechanical and microstructural characterization of neutron, ion and proton irradiated steels and model alloys M.I. Luppo et al., J. Nucl. Mater. (2000) Defect-free channel in the deformed proton-irradiated Fe-12Cr alloy at RT. Imaging conditions: g =<1 1 0>, z=<1 1 1>

3. WP4Deformation mechanisms at the grain scale in F/M steels Objective Develop a physically-based model of slip localization in steels accounting for the presence of C and Cr atoms Physically-based continuum model of slip localization T4.3.1: - Coupled diff. equations accounting dislocation defect interactions and evolution of their densities - SGCP to predict instability, bifurcation and patterning - Channeling threshold, channel thickness and plastic slip Inputs: Dislocation dynamics simulations: T4.1.4: NUMODIS T4.2.2: NUMODIS+FFT T4.3.2: TRIDIS Atomic scale simulations T4.1.1: - mobility law in Fe-C-Cr - dislocation defect interaction energetics (IP, DFT, DFTB) T4.1.2: - Cr, C, point defect (v) interaction synergy (DFT) - Fe-Cr-C potentials - Obstacle strength (MD) T4.1.3: - Dislocation GB interactions (MD) - Slip transfer conditions Stochastic model of defect dynamics T4.2.1: - Defect microstructure and interaction laws Output towards WP5 Experimental validation - TEM in situ straining experiments (T4.4) - AFM of surfaces (T5.4)

4. WP5Channeling at the polycrystal scale in F/M steels Objective Model mechanical behavior (including plasticity and damage) during and after localization. Deformation and Damage T5.2: Damage Development - Atomistic simulation of cavity nucleation - Continuum modelling of stress at slip band intersecting interfaces - Nucleation rate and cavity growth WP4 T5.1: Polycrystal homogenization: T5.1.1: Mean field homogenization - Modified localization rule accounting slip band matrix interactions - Introduce block boundary slip transfer conditions - Stress strain curve T5.1.2: Full field homogenization - Develop non-convex SGCP const. law - Channeling in 2D polycr. aggregates - Implement in ABAQUS - Stress strain curve T5.3: Constitutive equations to describe deformation and damage - Formulation of finite strain model - Account for ductile damage from T5.2 - Implement in ABAQUS - Stress strain curve T5.4 Experimental Validation T5.4.1: Camera-instrumented tests T5.4.2: TEM examination T5.4.3: AFM and SEM-FEG of surfaces

5. WP4 - Deformation mechanisms at the grain scale in F/M steels • T4.1: Elementary processes of plasticity (M1-M36)[CEA, CNRS, SCK, CIEMAT, UPC] Sub-Task 4.1.1: Dislocation mobility law (CNRS, CEA) Sub-Task 4.1.2: Atomic-scale mechanisms of interaction between dislocations and irradiation defects (SCK-CEN) Sub-Task 4.1.3: Mechanisms of the interactions dislocation-grain boundary to parameterize slip transfer (UPC) Sub-Task 4.1.4: Comparison in-situ TEM / DD simulations to validate the elementary processes of interactions (CNRS, CEA, CIEMAT) • T4.2: Meso-scale study of plasticity (M1-M48)[CEA, CNRS, CCFE, SCK] Sub-Task 4.2.1: Radiation defect microstructure in the context of dislocation dynamics simulations (CCFE) Sub-Task 4.2.2: Large-scale simulation of plasticity in irradiated single grains (CEA, CNRS) • T4.3: Continuum scale modelling of slip localization(M1-M48) [CEA] Sub-Task 4.3.1: Continuum modelling of slip localization (CEA) Sub-Task 4.3.2: Segment DD computations (CEA) • T4.4: Validation through the experimental study of slip localization(M1-M48) (CIEMAT, PSI, CEA) E. Gaganidze and D. Rodney M4F 1st plenary meeting

6. WP4 - Deformation mechanisms at the grain scale in F/M steels D4.1: Dislocation mobility law and strengthening coefficients due to the interaction between dislocations and irradiation defects in presence of Cr and C decorations (M36) [CEA, CNRS, SCK] D4.2: MD simulations of dislocation – grain boundary interactions (M36) [UPC, CIEMAT] D4.3: Meso-scale mechanisms of interaction between dislocations and irradiation defects (M36) [CNRS, CEA, UKAEA] D4.4: Large-scale simulation of plasticity in irradiated single grains (M36) [CNRS,CEA] D4.5: Continuum scale modelling of slip localization (M48) [CEA, JRC, METU] D4.6: Comparison between predictions and experimental observations (M48) [CEA, CIEMAT, JRC, PSI, SCK, METU] E. Gaganidze and D. Rodney M4F 1st plenary meeting

7. Task 5.1: Polycrystalline homogenization (M1-M36) [CEA, JRC, METU] • Sub-task 5.1.1: Mean-field homogenization accounting for channeling [CEA] • Sub-task 5.1.2: Full-field homogenization accounting for channeling [JRC, METU] • Task 5.2: Simulation of the damage initiation process during tensile loading as a consequence of channeling(M1-M48) [CEA, CNRS] • Sub-task 5.2.1: Cavitation/nano-cavitation mechanism under deformation of irradiated F/M steels [CEA, CNRS] • Task 5.3: Development of physically based constitutive equations for describing coupled deformation damage behavior of F/M steels(M1-M48) [KIT] • Sub-task 5.3.1: Development of physically based constitutive equationsdescribing the deformation damage behavior of F/M steels • Sub-task 5.3.2: Simulation of post-yield post-necking behavior • Task 5.4: Experiments to support modelling(M1-M36) [SCK, CIEMAT, CEA] • Sub-task 5.4.1: Experimental validation by camera instrumented mechanical tests [SCK] • Sub-task 5.4.2: TEM examination of irradiated and deformed materials [CIEMAT, SCK] • Sub-task 5.4.3: AFM and SEM-FEG study of surfaces of irradiated and deformed specimens [CEA, CEIMAT] WP5 - Channeling at the polycrystal scale in F/M steels E. Gaganidze and D. Rodney M4F 1st plenary meeting

8. WP5 - Deliverables • D5.1: Polycrystal mean-field and full-field homogenization predictions of tensile behaviour(M36) [CEA, JRC, METU] • D5.2: Ductile damage initiation in irradiated F/M steels and consequences in terms of continuous nucleation rate and cavity growth (M48) [CEA, CNRS] • D5.3: Physically based constitutive equations for describing deformation damage behaviour of F/M steels (M24) [KIT] • D5.4: Simulation of post-yield post-necking behaviour by using the UMAT implementation of the developed-constitutive equations; Impact of rational use of post yield post necking behaviour of F/M steels on the development of the advanced design rules (M48) [KIT] • D5.5: Determination of true stress true strain curves of irradiated F/M steels (M30) [SCK] • D5.6: SEM-FEG, TEM, and AFM study of ion, proton and neutron irradiated and deformed specimens (M36) [CIEMAT, CEA] E. Gaganidze and D. Rodney M4F 1st plenary meeting

9. Thank You very much for Your Attention!