The focus of the dissertation is the numerical modelling of die wear in processes with high thermal loads such as tailored tempering and die forging. For a realistic numerical representation of the resulting die wear, Felix Müller developed a method for investigating changes in hardness during die forging that takes into account not only thermal loads but also superimposed mechanical stresses. This showed that a superimposed mechanical load influences both the occurrence of tempering effects and the austenitisation of the die material. By implementing the findings in commercial finite element software, a quantitative prediction accuracy of the local die hardness of over 90 % was achieved in industry-related validation tests. A more precise knowledge of the local die hardness also enables a more realistic prediction of die wear.
His work also showed that process variations have a significant impact on wear prediction. Using an approach based on statistical methods, the influence of fluctuating semi-finished product temperatures on die wear was taken into account. The results show that the combination of real process data and numerical simulations can increase the accuracy of predictions.
In addition to the main topics of his research, he has also supervised other projects in the field of hot forging. Felix Müller's many years of intensive teaching assistance and his great commitment were of particular importance to the Institute.
The IFUM and his colleagues warmly congratulate Felix Müller on his successful doctorate and valuable contributions to the further development of wear models in hot forming.
