The effects of die geometry on the limit drawing ratio in deep drawing process of spherical cups.

In this study, the formability of dekape sheet metals which has very wide usage areas in the industry was investigated experimentally and numerically. Spherical punch geometry was used different from the novel literature. In order to make easy the plastic deformation process, the die and impression plates were machined with 0°,- 2,5°,-5°-7,5°-10°-12,5°-15° angle values. Die edges were also filleted in 6 mm radius to avoid the bending stress concentration. The impression forces were selected as 2450 N, 4900 N, 7350 N and 9800 N, respectively. According to force and angles? factor levels, a full factorial experimental design method was used.The punch forces during deep drawing process were measured with a load cell based on the time. The limit drawing ratio and wall thickness of the cups were determined. The experimental gathered data was analyzed with the help of ANSYS computer package programme. The experimental results were compared with computer analysis results and a good agreement between them was observed. As a consequence, the limit drawing ratio values observed with angular dies were higher than the non ? angular dies. The highest limit drawing ratios were measured as 1.98 and 2.42 for 0° and 15° angle values, respectively. Thus, it is concluded that it is possible to enhance the limit drawing ratio as 20% by using angular dies. Similarly, it was seen that the wall thickness values of samples were tendency of increase with angle values, too. The wall thickness values were measured as 0.7 and 0.84 for 0 and 15 degree values, respectively.