Multiscale framework-based crystal plasticity modeling and texture evolution of the deformation behavior of AISI 304 stainless steel microtubes manufactured through 3D-FBF technology

The grain size often influences the precision and quality of products manufactured by microforming at the microscale. Macroscale finite element modeling (FEM) cannot accurately predict nonuniform deformation and microstructural evolution at the microscale. In addition, the microscale FEM is challenging for forming processes with complex loading boundary conditions. Thus, in this study, a multiscale framework-based CPFEM is proposed to study the deformation behavior of microtubes manufactured through the 3D-FBF process. The acquired results show that significant nonuniform deformation is caused by greater geometric dimensions and smaller grain sizes, which increase the bending radius of microtubes at the macro level. In addition, a larger offset leads to higher flow stress, larger lattice rotation angles, and consequently, a larger bending radius for the microtube, and grain orientation also influences bending deformation, with easily deformable grain orientations leading to greater stress distribution within the grains.