Investigation of Inhomogeneous Deformation Behavior of Pure Copper Foils in Micro Deep Drawing

摘要

The inhomogeneous deformation behavior of pure copper foils in micro deep drawing is investigated by experiment and numerical simulation. In the experiment, the sheets with different thickness are firstly annealed to obtain different grain sizes. In the micro deep drawing experiments, as the ratio of thickness to grain size decreases, deformation inhomogeneity increases, represented by more irregular edge shape, rougher surface, and "double peaks" in the load-stroke curve. In the numerical simulation, a non-local dislocation density based crystal plasticity model is adopted. The influence of orientation distribution of the grains is captured by the plasticity model, while the inhomogeneous deformation inside a grain is described by the evolution of dislocation density, including those of statistically stored dislocations (SSDs) and geometrically necessary dislocations (GNDs).