Project Details
Projekt
Microstructure simulation of solidification in the weld
Subject Area
Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale
Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 434946896
In the scope of the joint project ''Solidification Cracks in Laser Beam Welding (LBW): High Performance Computing for High Performance Processes'', subproject TP6 aims to achieve a fundamental understanding of the physical mechanisms of solidification crack formation and dynamic propagation in Ni-based superalloys on the microscale through chemo-thermo-mechanical modelling and solidification simulation. Based on validation by comparison with experimental measurements from the subprojects of the research group and embedded in a multi-scale approach, the phase-field method with combined continuum modelling allows a far-reaching prediction of the microcrack distribution and degradation probability. Using a fully coupled chemo-thermo-mechanical phase-field model, the stress and strain profiles during solidification and the subsequent solid phase transformations are accurately predicted as a function of location and time. This allows the stress and strain excesses between the forming phases to be accurately determined. Crack probabilities are then modelled using the concepts developed in the first phase of the project for predicting local thermal and chemical inelastic strains. In addition, anisotropic and depletion zone-dependent fracture strength properties are included to account for the complex microstructural characteristics of the alloys. Through integration into the workflows of the Kadi4Mat research data infrastructure, simulation studies will be automated to provide design suggestions for setting optimal compositions and process parameters to minimise solidification cracking, thereby making a significant contribution to the computer-aided accelerated development of stable welded joints in advanced superalloys. Finally, the project aims to quantitatively predict statistical parameters such as the distribution, proportion and rates of solidification cracking at the microscale. These results are homogenised and transferred to mesoscopic scales to enable theoretical predictions and evaluations of solidification cracking at mesoscopic and then macroscopic scales. The microscale investigations are an essential part of the multiscale approach, which captures the multiple-scale events of micro-, meso- and macroscopic material behaviour and provides important insights for the development of robust, crack-resistant welded joints in Ni-based superalloys for high-temperature applications in aerospace and power generation.
DFG Programme
Research Units
