Development of physically based simulation chain for microstructure evolution and resulting mechanical properties focused on additive manufacturing processes

Executive Summary:

Powder bed based additive manufacturing processes belong to the key technologies of the future. They allow the production of complex shaped components from the powder with nearly no waste. To improve the process control and to identify proper process operation-windows, ensuring part integrity and stable mechanical properties, further research on the interactions between the process and the specific material to be processed is required. Here, the SIMCHAIN-project wants to contribute with the development of a new multi-scale material-simulation approach.

The aim of the project was to establish a full software set, which allows the prediction of resulting mechanical properties of materials produced by additive manufacturing using Selective Electron Beam Melting as a function of the process parameters. In order to realise this goal, we coupled three simulation modules covering all the essential physical mechanisms on relevant length- and time-scales: The melting, initial grain structure and orientation formation of the powder particles upon electron beam interaction was simulated via Lattice-Boltzmann and Cellular Automata approaches; the initial microstructure formation during rapid dendritic solidification at micrometer-dendritic arm-spacing length and solidification time-scales were covered by the phase-field module; the thermo-mechanical behaviour of the resulting grain structure at heat-treatment-time-scales will be simulated using a crystal plasticity Finite Element simulation module.

Furthermore, the development of the simulation models were accompanied by experiments to define essential material parameters and to calibrate, validate and optimise the derived models. SIMCHAIN was an innovative and unique approach to build a ready to use software set in order to predict the influence of various process parameters on the resulting mechanical properties during additive manufacturing using Selective Electron Beam Melting. SIMCHAIN prepared the ground for robust process design, as an important step towards design-driven manufacturing for future aero engines parts optimized in weight and function.