Deep drawing of nickel foil and stainless steel foil

摘要

The blankholding pressure required to prevent wrinkling increased considerably with a decrease of blank thickness. The maximum deep-drawing stress also increased greatly with an increase of the blankholding pressure, according to the decrease of blank thickness. Fractures and wrinkles in deep drawing of stainless steel foil and nickel foil occurred easily and the deep drawability deteriorated. In order to form metal foil cups without failure, blankholding pressure should be loaded along optimum paths. In addition to the failure due to the decrease of blank thickness, tooling imperfections such as ununiform contact between tools and the foil blank, unequal clearance along the circumference and inaccurate alignment between the punch, die and blank greatly influence the onset of wrinkling and fracturing. The use of auxiliary sheets in deep drawing of stainless steel foil and nickel foil reduced the influence of tooling imperfections and prevented wrinkling and fracturing. As a result, the deep drawability of metal foil was considerably improved.