Effects on the deep drawing diagram in micro forming

Abstract

The limits of the processing window for deep drawing, collected in a deep drawing diagram, are affected by material behavior, process parameters and size effects. A size effect, more specific a density effect, explains the changes in forming behavior of foils with respect to the forming limit, denoted by the limiting drawing ratio. It is shown that it occurs in so called Tiffany structures. The changes in the tribology in deep drawing have an influence on the clamping limit of the processing window. The changes are induced by changes of the drawing speed. They can be explained by the lubricant pocket model only if one takes the temperature dependence of the viscosity of the lubricant into account.