Electro-thermo-mechanical modeling of Field Assisted Sintering Technology using high-order finite elements validated by experiments

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Field assisted sintering technology (FAST) is a modern manufacturing process, where during the sintering process powder compaction is performed. Fast heating and cooling yield shorter production periods and improved material properties. Caused by the high temperatures, which are induced in the graphite tools and the powder material by an electrical potential, an experimental measurement of the internal processes are hardly realizable. Thus, numerical methods are adequate, which, however, must be based on both experimental-based models as well as validated in view of their predictability under consideration of uncertainties in the measurements. In this project the entire process in the testing machine will be gathered and modeled with constitutive models for both the tools and the powder workpiece. Particularly, the coupled electrical, thermal and mechanical properties must be considered. The constitutive models are implemented into a high order space and time finite element program, where, additionally, the coupled three-field problem must be solved. Accordingly, new concepts for an efficient and robust computation of coupled problems using a partitioned approach applied to electro-thermo-mechanical coupling will be developed so that even radiation with reflection can be considered. In the case of high order finite elements an efficient space integration is required. Highly accurate results of the electro-thermal subproblem of the moving regions will be achieved using adaptive/hierarchical finite cell approach, which implies the further development of the finite cell method in view of coupled problems. These highly complex and challenging issues are only possible within collaborating partners coming from different disciplines such as material science, mechanics and numerics leading to new contributions applicable even to further multi-physical issues.