Entwicklung einer Methodik für die Abbildung von Beschichtungsmitteln in FEM-Warmumformsimulationen

The present work provides an overview of the most important influencing factors in closed die forging of coated components. Friction mechanisms are described, mathematical models for their implementation in hot forming simulations are presented, the physical basics of heat transfer (heat conduction, convection, and thermal radiation) are summarized, and the fundamental functionality of thermocouples and thermographic cameras are explained. In this work, methods for obtaining thermophysical input parameters (convection and emission coefficients) for FEM simulations are presented based on experiments. The influence of coatings on forming force and friction is investigated based on tests with components on a screw press. In the simulation part, the influence of various parameters on the simulation results is first investigated based on simulation studies. Subsequently, a methodology is shown how the experimentally determined data has to be prepared for the simulation software DEFORM of the company SFTC. The conducted component tests are simulated with different settings. By comparing the simulated and measured forming forces, suitable friction models and matching parameters are then selected, in order to get the most accurate representation of coating materials in the simulation. The methods presented in this work serve as a basis to investigate further combinations of materials and coatings and considering them in forging simulations.