Mesoscale simulations of microstructure and texture evolution during deformationof columnar grains

摘要

In recent years, microstructure evolution in metals during deformation processinghas been modeled at the mesoscale by combining the finite element method to discretize the individual grains with crystal plasticity to provide the constitutive relations. This approach allows the simulations to capture the heterogeneous natutre of grain deformations due to interactions with neighboring grains. The application of this approach to study the deformations of columnar grains present in solidification microstructures is described. The microstructures are deformed in simple compression, assuming the easy growth direction of the columnar grains to be parallel to the compression axis in one case, and perprendicular in the other These deformations are similar to those experienced by the columnar zones of a large cast billet when processed by upsetting and drawing, respectively. The simulations show that there is a significant influence of the initial microstructure orientation relative to the loading axis on the resulting changes in grain shape and orientation.