b'Stress-Strain & DuctilityTensile FEtesting analysisTexture and Grain size of polycrystalline aggregatesConstitutive law of PolycrystalsMicrostructural defectsin grainsMechanisms-based single Orientationcrystal plasticity modelDeformation-induced Irradiation-induced defects temperature sample sizeMicro-mechanical testsof single crystalsFigure 1. Schematic of objectives: Bridging micro-scale to macro-scale mechanical property measurements and prediction of performance limitations for FeCrAl alloys under extreme reactor applications. At the meso/micro-scale, we explore the correlation of microstructural defects with micro-mechanical properties of FeCrAl alloys and thereby develop the Mechanisms-based Single Crystal Plasticity model (MSCP); At the micro/maro-scale, we develop the Constitutive Law for Polycrystals (CLP) by implementing the MSCP into the Visco-Plastic Self-Consistent (VPSC) model and validating the CLP by comparing macro-mechanical tests; Lastly at the macro-scale, we implement the CLP into finite element analysis to predict the ductility of FeCrAl alloys following mechanical deformation and/or radiation2022|AFC ACCOMPLISHMENTS 45'