Towards the full modeling of microstructure evolutions during metal forming industrial processes
Résumé
The mechanical and thermal properties of metallic materials are strongly related to their microstructure.
The understanding and the modeling of the microstructural evolution mechanisms is then crucial
when it comes to optimize the forming process and the final in-use properties of the materials.
Macroscopic and homogenized models, also called mean-field models are widely used in the industry, mainly
due to their low computational cost. They are generally based on empirical laws and thus require many
fitting parameters which must be calibrated through experimental testing or lower-scale simulations.
Furthermore, given the complexity of modern metallurgical problems, these models may not be accurate
enough to capture local but significant events. Thanks to the explosion of computer capacities, finer modeling
techniques are now available.
These lower scale approaches, the so-called full field models, are based on a full description of the microstructure topology and are used for a
wide range of metallurgical mechanisms (recrystallization, grain growth, Smith-Zener pinning, solid/solid phase tranformations and more
globally diffusion mechanisms,...). One major difficulty, which will be discussed in this presentation, is to propose an efficient and precise global
numerical framework allowing to take into account the principal and concommitant mechanisms at work during metal forming. This objective
becomes crucial when industrial applications with realistic thermomechanical paths are considered.
The capabilities of recent developments, based on a finite element - levet set numerical framework, to model, at a representative volume
element scale, microstructure evolutions during industrial thermomechanical paths and for differents materials will be illustrated.