The thickness profiles for the expe

The thickness profiles for the experimental and simulated funnel show good correlation as seen in Fig. 3. The two profiles start with an initial thickness of 1.64 mm and exhibit progressive thinning until the material reaches the bending area [15] and the variable forming angles (15°–70°) begin at ~7 mm in depth. As the forming angle increases, thickness decreases until a minimum value of 0.56 mm is reached at the highest wall angle. Thickness increases again, until forming has finished. To validate thickness prediction for the funnel, thinning values for a 45° and 67° wall angle SPIF cone in regions of steady state, determined in a previous work, were added [15]. The plot in Fig. 3 shows a very good agreement between the funnel and the two cones and the behavior is consistent with the sine law prediction [15].