Workshop « bridging space-time scale… », DRESDEN, September 2016 Maylise Nastar CEA Saclay, France Bridging space-time scales in the field of diffusion-controlled phase transformations Part of this work was supported by o the joint program "CPR ODISSEE" funded by AREVA, CEA, CNRS, EDF and Mécachrome under contract n° 070551. o NEEDS Materiaux o JPNM/Matisse/Mefisto
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Bridging space-time scales in the field of diffusion …Workshop « bridging space-time scale… », DRESDEN, September 2016 Maylise Nastar CEA Saclay, France Bridging space-time scales
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Workshop « bridging space-time scale… », DRESDEN, September 2016
Maylise NastarCEA Saclay, France
Bridging space-time scales in the field of diffusion-controlled
phase transformations
Part of this work was supported by
o the joint program "CPR ODISSEE" funded by AREVA, CEA, CNRS, EDF and Mécachromeunder contract n°070551.
o NEEDS Materiauxo JPNM/Matisse/Mefisto
Atomic diffusion model
Macroscopic diffusion and flux coupling: diffusion equations
d ≈ aΔt ≈ a2 max(ωVA)
d ≈ naΔt ≈ d 2 DB
nano2
(10 )100 V VA
d n at n C»
D » w
Nucleation in dilute alloysCluster Dynamics, OKMC
A multiscale approach for diffusion and phase transformations
d ≈ Vat3 /CBΔt ≈ d 2 max(Mcluster )
Nanoscale diffusion & spinodal decompositionin concentrated alloys: phase field methods
𝑤"#=Γ"𝑒& '()
Growth and coarsening
d ≈ Vat3 /CBΔt ≈ d 2 max(Mcluster )
JB = − Lijj∑ ∇µ j
Atomic diffusion model
Macroscopic diffusion and flux coupling: diffusion equations
d ≈ aΔt ≈ a2 max(ωVA)
d ≈ naΔt ≈ d 2 DB
nano2
(10 )100 V VA
d n at n C»
D » w
Nucleation in dilute alloysCluster Dynamics, OKMC
A multiscale approach for diffusion and phase transformations
d ≈ Vat3 /CBΔt ≈ d 2 max(Mcluster )
Nanoscale diffusion & spinodal decompositionin concentrated alloys: phase field methods
𝑤"#=Γ"𝑒& '()
Growth and coarsening
d ≈ Vat3 /CBΔt ≈ d 2 max(Mcluster )
Interactions between cells?nanoscale fluctuations and nucleation?
Flux couplings?
JB = − Lijj∑ ∇µ j
Irradiation of Fe-15 % Cr by e- 1MeV (THT)T=773 K, F=3.9x10-5 dpa/s, dose=0.2 dpaO. Tissot, E. Meslin et al. (CEA-SRMP & Univ. de Rouen)
Atom Probe Tomography(GPM,Rouen)TEM – Bright field (CEA Saclay)
Microstructure of point defectsInterstitial loops a<100>
Radiation Induced Segregation (RIS) of Cr at loops due to flux couplings
A typical phenomenon involving bothPoint defect-solute cluster reactions and flux coupling
what is the effect of point-defect microstructure on RIS?what is the effect of RIS on the point defect microstructure?
200 nm
Continuous diffusion equations
Negative flux coupling
Spatial cluster dynamics (Crescendo)Object kinetic Monte Carlo
A typical phenomenon involving bothcluster reactions and flux coupling