Successfully completed doctorate
On 24 September 2020, Dr Pierre Landgraf successfully defended his dissertation thesis entitled „Microstructure and hardness development during laser beam treatment of high-alloy tool steels“. The successful completion of the doctoral procedure was again achieved through a combination of classroom and online elements.
Using the Big Blue Button conference system of the TU Chemnitz, numerous other guests were able to follow Dr Landgraf's explanations in addition to the doctoral committee present. His research work started with the observation that little research had been done on the laser beam hardening of high-alloy tool steels, especially thin components. In addition, no numerical simulations of laser beam hardening had been applied to high-alloy tool steels to date. Both shortcomings served as motivation for Dr Landgrafs' work. It was important to note that, depending on the temperature field during laser beam hardening, the locally occurring hardening process parameters vary, which has a direct influence on the solubility of alloying elements in the heated state and thus on the resulting microstructure after the self-quenching process. These temperature field-dependent variations had to be taken into account for the successful numerical simulation of the laser beam hardening of the high-alloy steels, as standardly implemented FE material models do not take these dependencies into account. As a result, however, Dr Landgraf successfully closed this gap for two selected frequently used high-alloy tool steels. He was thus able for the first time to make an almost exact simulative prediction of the hardness levels and hardness depth curves of the investigated materials as a result of laser hardening processes with different process parameters.
The work will soon be published under the IWW's own publishing house in the publication series „Materials and Materials Engineering Applications“ and in the Qcosa portal of the TU Chemnitz.
Image:
Prof. Thomas Lampke (doctoral supervisor and first reviewer), Dr. Pierre Landgraf, Prof. Thorsten Halle (second reviewer) and Prof. Michael Groß (head of the doctoral procedure)
8.10.2020 – Personnel of the professorship ( thomas.grund@mb… )
