Grain size effect analysis of progressive meso-scaled forming aided by coupled Eulerian-Lagrangian approach and CPFEM

Abstract

For the mass production of complex-shaped components, progressive meso-scaled forming is a viable and pragmatic process, offering a balance between product precision and manufacturing output. In designing and optimizing this meso-forming process, the conventional finite element method (FEM) may not furnish all needed solutions, as it is mainly developed for macro-scaled forming processes. In contrast, within the meso-forming process, the size effect (SE) must be adequately considered and accounted for. In this study, novel simulation methodologies, namely the coupled Eulerian-Lagrangian approach (CEL) and the crystal plasticity finite element method (CPFEM), are introduced to investigate the SEs in progressive meso-forming processes. Utilizing a pure copper gear shaft fabricated via progressive meso-forming, a comprehensive comparative analysis was performed among FEM, CEL, and CPFEM with respect to computational efficiency, dimensional precision, microstructural evolution, surface quality, and the associated SEs. It is demonstrated that CEL is an effective and cost-efficient tool for predicting material flow dynamics, the formation of shear bands, and material flow patterns. Moreover, CEL and CPFEM can more accurately capture the SEs on microstructural evolution and dimensional accuracy compared to conventional FEM. Based on research into similar components, the relationship between the extrudate length variation and grain size is elucidated and established. This study offers valuable insights into the realms of quality control, deformation mechanisms, and the intricacies of internal grain SEs, and it serves as a benchmark for the application of CEL and CPFEM in the simulation of complex-shaped part forming processes. The findings also contribute to a deeper understanding of the progressive meso-forming process and its application in the mass production of meso-scaled components.