Modélisation de la phase de compaction du procédé CIC à l'échelle mésoscopique

During HIP of metal powder, power-law creep is the dominant mechanism during the densification process. However, the understanding othe global impact of the thermo-mechanical boundary conditions and of the powder granulometry on the microstructure obtained after this first mechanism is not straightforward. A finite element methodology based on the use of a level set framework coupled with a remeshing technique is pro posed in order to model the viscoplastic deformation of powder particles during HIP at the m esoscopic scale thanks to a Representative Elementary Volume (REV). The methodology consists i n generating, in a finite element mesh, a sphere packing of particles by representing implicitly all particles by means of a limited set of level-set functions. Mesh adaptation is also performed at par ticle boundaries to describe properly the particles and to manage the discontinuity of the physical pro perties between the two media (particles and inter- particle space). The inter-particle space is consid ered as a compressible Newtonian fluid. Such mesoscopic densification simulations are presented and discussed.