Development of finite element procedures to model the behavior of ultra-fine-grained and nanocrystalline grain structures during Equal-Channel Angular Press (ECAP) processing of metals

摘要

In this paper, the effects of grain size and misorientation angle on the deformation are examined in order to see how microstructural features might explain the observed increase in strength of ultra-fine-grained and nanocrystalline metals and alloys using ECAP technique. The study investigates the behavior of grain structures during ECAP process using the commercial two-dimensional elastic-plastic finite element code (Abaqus/explicit.) with the Arbitrarily Lagrangian Eulerian (ALE) and re-meshing method in the software. The paper successfully demonstrated efficient finite element technique which makes the stress field dependent on the grain size and angle of misorientation between the grains. This approach is much more simple and easier to relate the model to real material as it offers a simple method of including grain size effects and grain misorientation to which we could add additional phenomena through developing the material model used to describe the anisotropy and techniques that would automatically re-mesh the refined grain structure produced under severe plastic deformation. This study will form a foundation for future studies to describe the behaviors of ultra-fine-grained and nanocrystalline metals and alloys.