Field fluctuations elasto-plastic self-consistent crystal plasticity: Applications to predict texture evolution during rolling, recrystallization, and drawing processes

This paper advances a mean field elasto-plastic self-consistent (EPSC) model to a higher-order model, calculating the second moments of lattice rotation rates and resulting intragranular misorientation spreads, based on the second moments of stress fields inside grains. The novel formulation is named field fluctuations (FF)-EPSC. The calculated intragranular misorientation spreads are used to conceive a grain fragmentation model to improve the predictions of deformation texture evolution and a recrystallization model to enable the predictions of recrystallization texture evolution, by modeling transition-bands and grain boundary nucleation mechanisms along with stored energy to govern recrystallized grain growth. The FF-EPSC incorporates a dislocation density-based hardening law for the evolution of slip resistance and a backstress law to influence the activation of slip systems. Simulations of tension followed by static recrystallization of an aluminum alloy (AA) 5182-O and rolling followed by static recrystallization of an interstitial-free steel were used to benchmark the accuracy of the model. Remarkably, the model predicted recrystallization textures after predicting the deformation textures while revealing the tradeoffs between transition-bands and grain boundary nucleation mechanisms. Moreover, predicted intragranular misorientation spreads after tension of AA5182-O agreed well with the corresponding measurements. The FF-EPSC model was further integrated in the implicit finite element (FE) method as a user material subroutine in Abaqus to facilitate predicting geometrical shape changes under complex boundary conditions with every integration point embedding the FF-EPSC constitutive law. The FE-FF-EPSC model was applied to simulate the sequence of processes involving rolling, recrystallization, and deep-drawing of an AA6022-T4 cylindrical cup.