Speaker
Description
Mastering mechanical properties in metallic parts made by laser powder bed fusion (LPBF) process is of paramount importance. In this process, a deposited powder layer is melted by a laser and solidifies instantaneously when the laser moves away. During the solidification, the microstructure of the part is formed due both to epitaxial grain growth and nucleation process. As a consequence, the prediction and characterization of this microstructure is of prime interest considering size, crystallographic orientations and shapes of grains. Indeed, this structure has a strong influence on the final mechanical properties of parts and is influenced by the choice of process parameters such as the laser power, the scanning velocity or the laser radius.
Among the approaches reported in the literature to model microstructure development, the Cellular Automaton (CA) method is a relevant choice to describe grain structure evolution. This model has been adapted and applied to investigate microstructure evolution formed during LPBF process applied on an IN718 nickel-base superalloy.
The steady state thermal behaviour of the built part during the process is analysed and used by the CA model to compute grain growth kinetics. Thanks to the parallelization of the computation, the grain structure is computed at the scale of the part, which, to the best of our knowledge, was not accessible so far. Results are compared to experimental observations, showing similar evolutions.
| Speaker Country | France |
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