Influence of tool geometry variations on the limiting drawing ratio in micro deep drawing

In this study, the impact of different tool geometries on the limiting drawing ratio (LDR) in micro deep drawing was investigated. Experimental micro deep drawing tests to determine the limiting drawing ratios were carried out for a variation of the punch diameter, the die radius and the die clearance. In order to assess the impact of the material properties on the process limits the foil materials Al99.5 and E-Cu58, both with a thickness of 20 μm, and the stainless austenitic nickel-chromium steel 1.4301 (X5CrNi18-10) with a thickness of 25 μm were investigated. The results reveal an increase of the limiting drawing ratio with increasing die radius size for the foil materials E-Cu58 and austenitic steel. For a decrease of the die clearance to values smaller than 1.25 times the foil thickness an increase of the limiting drawing ratio was determined for all three materials.