Effect of tool geometry variations on the punch force in micro deep drawing of rectangular components

In this study, the impact of tool geometry variations on the punch force in micro deep drawing of rectangular parts was investigated. In contrast to deep drawing of rotationally symmetrical components in deep drawing of rectangular parts further tool geometry parameters, such as the corner radii of the die and punch influence the process and the process result. However, their impact on a micro deep drawing process is not known. Experimental micro deep drawing tests, as well as FEM simulations were carried out to determine the punch forces for a variation of the corner radius and the die radius. It could be demonstrated that an increasing corner radius size leads to an increasing punch force in deep drawing. Enlarging the corner radius from 147 to 250 µm resulted in a 36 % higher punch force. In contrast, an increase of the die radius size results in a decreasing punch force. Here, enlarging the die radius from 76 to 143 µm led to a decrease of the punch force of 26 %.