Collaborative Research Centre 708

Logo CRC 708 project

3D-Surface Engineering of Tools for Sheet Metal Forming - Manufacturing, Modeling, Machining

The production of high-strength structural elements made of sheet metals for the automotive and the aerospace industries using forming processes requires the use of highly productive tool systems. On the one hand these tools have to provide a long service life for the forming of high-strength steel sheets in the middle or large-scale production. On the other hand the tools have to feature a high dimensional accuracy and surface quality to achieve a high and consistent component quality. These properties have to be provided by the tools, which generally feature a very complex geometry, even at a large number of forming operations. The development and manufacturing of forming tools is a time-consuming and cost-intensive process. An early tool wear does not only lead to loss of the shape accuracy of the formed components, but with advancing wear also to a machine breakdown. Apart from the exchange of the tools, the rework of faulty shaped sheet metal parts also causes considerable costs. Against this background the optimal design of forming tools, especially with regard to their wear resistance and its shape accuracy is of particular importance. To counteract this problem, the SFB 708 develops and investigates a novel manufacturing methodology for the economical and resource-efficient production of highly wear-resistant tool surfaces for the forming technology based on thermally sprayed near net shape coatings. The novel manufacturing method of the "Augmented 3D Surface Engineering" is characterized by the additional integrated virtual modeling of all manufacturing steps. The purpose of the virtual modeling is the practical connection of a wide range of surface engineering manufacturing techniques consisting of milling, thermal spraying, rolling and grinding to a manufacturing process chain as well as the simulation-based validation of the forming using the resulting tool. Beside the production of high quality tools with a low amount of iteration steps the virtual modeling serves to reduce, or in the ideal case to eliminate trial-and-error experiments. The overall objective of the SFB 708 is the realization Augmented 3D Surface for the production of coated forming tools. This comprises a variety of sophisticated questions related to the material engineering, the manufacturing, the forming, the mathematical modeling, the simulation and optimization as well as efficient algorithms and data structures, which have to be solved and are the subject of the projects in the SFB 708. To realize this, a special feature of SFBs lies in the interdisciplinary cooperation between engineers and methodologists from the fields of mechanical engineering, mathematics, computer science and statistics at the TU Dortmund.

Co-PI of subproject B7: Modeling and Numerical Simulation of Thermal Spray Coating Processes

The objective of TP B7 is the design of numerical methods for simulation and optimization of thermal spray coating. The main focus is on a unified approach to mathematical modeling of individual processes and inclusion of effects that have been neglected so far. The collaboration with TP A1 shall enhance the performance of the electric arc spraying system by using custom-made Laval nozzles and secondary gas inlets for adaptive control of the particle-laden free jet. A further objective is the coupling of stand-alone subproblem solvers and their embedding into a modular simulation toolbox for the entire process chain.