Modeling of Microstructure Effects on the Mechanical Behavior of Ultrafine-Grained Nickels Processed by Severe Plastic Deformation by Crystal Plasticity Finite Element Model

In this study, a crystal plasticity finite element model (CPFEM) has been revisited to study the microstructure effects on macroscopic mechanical behavior of ultra-finegrained (UFG) nickels processed by severe plastic deformation (SPD). The microstructure characteristics such as grain size and dislocation density show a strong influence on the mechanical behavior of SPD-processed materials. We used a modified Hall-Petch relationship at grain level to study both grain size and dislocation density dependences of mechanical behavior of SPD-processed nickel materials. Within the framework of small strain hypothesis, it is quite well shown that the CPFEM predicts the mechanical behavior of unimodal nickels processed by SPD methods. Moreover, a comparison between the proposed model and the self-consistent approach will be shown and discussed.