Séminaire CEMEF de Marc Bernacki
Is the equation V=MP really to be abandoned for recrystallization and grain growth modeling at the polycrystal scale? The pros and cons.
Marc Bernacki présentera ce séminaire lundi 18 mars 2024 à 10h00, amphithéâtre Mozart, Campus Pierre Laffitte.
Is the equation V=MP really to be abandoned for recrystallization and grain growth modeling at the polycrystal scale? The pros and cons.
Résumé :
Although grain growth (GG) mechanism is known for more than one century, it remains a hot research topic. The historical background has brought us to the current global picture: GG is driven by the minimization of grain boundary (GB) areas in order to decrease the total interfacial energy.
Thus, at the mesoscopic scale, the GB velocity is assumed to be the product of the GB mobility and the capillarity pressure defined as the product of the GB energy and the trace of the curvature tensor .
The recent improvements of GG experiments now make it possible to discuss in a much more precise way the veracity of this picture. Non-destructive in-situ experiments allow to avoid bias inherent to 2D observations and open the path to precise reverse engineering of the V/K ratio. The interpretation of these recent results tends to refute or at least to question the impact of curvature or to dispel the 5-parameter description of the reduced mobility. Using a new full-field framework, it will be illustrated how topological and torque effects can complicate GB dynamics and so weigh the current discussion concerning the validity or invalidity of equation for GG.
Marc Bernacki est Professeur Mines Paris, responsable de l'équipe MSR et du consortium DIGIMU.
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