Benjamin Scholtes

Improvement of 3D mean field models for capillarity-driven grain growth based on full field simulations

In the present study, mean field models of grain growth (Hillert and Burke–Turnbull models) are compared with 3D full field simulations considering an isotropic grain boundary energy and mobility and under the absence of second-phase particles. The present 3D full field simulations are based on a level set description of the grain interfaces within a finite element framework. The digital initial microstructures are generated using a coupled “Voronoï–Laguerre/dense sphere packing” algorithm. Based on full field simulation results, new formulations of Burke–Turnbull and Hillert models are proposed. In contrast with classical formulations, the new ones account for the possible heterogeneity of the initial grain size distribution.

Advances in Level-Set Modeling of Recrystallization at the Polycrystal Scale - Development of the Digi-μ Software

The mechanical and thermal properties of metallic materials are strongly related to theirmicrostructure. An accurate and quantitative prediction of microstructural evolutions is then crucialwhen it comes to optimize the forming process. Recently a new full field approach, based on a Level-Set (LS) description of interfaces in a finite element (FE) context has been introduced to model 2D and3D primary recrystallization (ReX), including the nucleation stage [1, 2], and has been extended to takeinto account the grain growth (GG) stage [3, 4]. The ability of this approach to model also the Zenerpinning (ZP) phenomenon without any assumption concerning the shape of second phase particleswas also demonstrated [5]. Moreover, recent developments have also illustrated the capability of thisapproach to take into account the characteristics of twin interfaces during grain boundary motion [6,7]. Current work concerns also the improvement of the numerical cost of this new approach [8]. Allthese developments are necessary to account for the microstructural complexity of ReX phenomenon.