Pvd Coating and Up-to-date Wear Test of Hot-Forming Tools

Recently, the requirements for decreasing the tool costs have been increased in forging technologies. These costs could be decreased by increasing the lifetime of the tools. In hot-forming there is a new possibility to increase the lifetime, namely: Physical Vapour Deposition (PVD) coating of the tools. Participants in testing the effects of coating were the employees of the Universtiy Szechenyi Istvan, Raba Axle Ltd., Fraunhofer Institut fur Schicht- und Oberflachentechnik Braunschweig and Westsachsische Hochschule Zwickau. Lately, pre-upsetting used in production lines served by robots – as upsetting made between parallel pressure plates used frequently in die-forging – was used to make wear tests. In the wear tests, the friction work according to the energetic model was calculated by applying a kinematically admissible velocity field, which takes into account the friction coefficient and the local displacements. Expectable friction coefficient – using the results of previous researches – has been determined based on geometrical data of the pre-upset work-piece.