Finite element study and sensitive analysis of the deep-drawing formability of commercially pure titanium

This paper describes a 3D finite element model used for optimizing the deep-drawing formability of a commercially pure titanium cap designed for the cosmetic industry. The results obtained from a specific tooling and various tensile tests highlight a strong anisotropic behavior of the material (earing profile on the parts and Lankford coefficients very sensitive to the loading direction). The mechanical behavior taking this anisotropy into account is described according to an elastic-plastic model based on the quadratic Hill’s criterion. A special attention is paid to studying the sensitivity of the FEM predictions with respect to the numerical parameters. The type and number of elements in the thickness of the blank and the friction coefficient have a significant influence on the numerical results. The comparison with the experiments taking the springback into account shows that the FE model is suitable for describing the behavior of titanium during a forming process such as deep-drawing. A Forming Limit Diagram is finally given to predict the feasibility and optimize the forming operation.