Effect of friction coefficient in deep drawing of AA6111 sheet at elevated temperatures

The effect of friction coefficient on the deep drawing of aluminum alloy AA6111 at elevated temperatures was analyzed based on the three conditions using the finite element analysis and the experimental approach. Results indicate that the friction coefficient and lubrication position significantly influence the minimum thickness, the thickness deviation and the failure mode of the formed parts. During the hot forming process, the failure modes are draw mode, stretch mode and equi-biaxial stretch mode induced by different lubrication conditions. In terms of formability, the optimal value of friction coefficient determined in this work is 0.15. At the same time, the good agreement is performed between the experimental and simulated results. Fracture often occurs at the center of cup bottom or near the cup corner in a ductile mode or ductile-brittle mixed mode, respectively.