| It is difficult for titanium alloy sheet to be formed at room temperature because of its narrow range of plastic deformation, having a tendency to crack, and its evident springback. Distinct shape transformation affected the geometrical precision of deformed components after unloading process. For these reasons, research on deep drawing and shape rule of deformed cups with TC1M and TC2M titanium alloy sheets was presented in this paper.Unilateral tensile test has been performed with TC1M and TC2M titanium alloy sheets. Based on the main performance parameters measured by tensile test, the finite element method simulation process of cup deep drawing was carried out using DYNAFORM software. Three kinds of shape unconventionality phenomena was revealed through the FEM simulation of unloading process: the cup edge thickness distribution becomes uneven, the cup lip presents earing and the inside surface profile of cup lip is no longer a circular shape. In the meantime, inherent laws of these phenomena are described.The cup deep drawing experiments were conducted with TC1M and TC2M titanium alloy sheets at room temperature. Several conclusions of analysis and comparison between FEM simulations and forming tests could be drawn as follows:(1) Although there is no failure of cracks or wrinklings in some condition, three kinds of shape unconventionality phenomena can still appear after unloading process at room temperature.(2) The same law was obtained upon the shape unconventionality phenomena with TC1M and TC2M titanium alloy sheets between simulation of cup deep drawing and tests.(3) Through quantitative analysis, FEM simulation was validated on the shape unconventionality phenomena due to agreement of two approachs.The shape unconventionality phenomena of cup deep drawing with titanium alloy sheets after unloading process is the result of uneven strain distribution produced by remarkable in-plane anisotropy together with great springback. |
