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

Abstract

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 Széchenyi István, Rába Axle Ltd., Fraunhofer Institut für Schicht- und Oberflächentechnik Braunschweig and Westsächsische 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.