Hybrid deep drawing tool for lubricant free deep drawing

This paper presents a concept for a hybrid deep drawing tool based on polymer concrete and first results from actual deep drawing tests using a prototype of the newly developed tool. The hybrid tool presented here has a defined macro-structure of the blankholder and drawing die as implemented before by Brosius et al. [1] in a steel tool for a lubricant free deep drawing process. The macro structure has a positive effect on the lubrication free deep drawing process, because it reduces the contact surface, increases the sheet’s stability against wrinkling in the flange, reduces the necessary blank holder force and thereby the contact pressure, and offers a means to control the material flow [1]. The main objective in transferring this concept to a new hybrid tool from polymer concrete is an enhanced possibility to easily integrate other functional elements like temperature and pressure sensors, graphite inlays or roller bearings into the drawing die or blankholder. Since polymer concrete is cast in a cold exothermal process of no more than 60° Celsius, these elements are not subjected to high thermal loads and their positioning is relatively simple and precise. Polymer concrete moreover has good mechanical properties regarding compressive strength [2] and Young’s modulus [3] and is therefore well suited for a deep drawing tool application.