POLYCRYSTALLINE MODELLING OF UDIMET 720 FORGING - Archive ouverte HAL Access content directly
Books Year : 2008



A crystalline modelling of deformation implemented in a finite element code coupled to a recrystallization Cellular Automaton code is proposed and applied to forging processes of superalloys. The coupled modelling is used in order to obtain a better understanding of the microstructural evolution of superalloys during high temperature forging at different strain rates and temperatures. The framework of the modelling is large plastic deformation and large lattice rotation. The used internal variables are dislocations densities on slip systems of the different phases. Modelling is based on viscoplatic constitutive and hardening laws at the scale of the slip systems and describes local strain and stress fields as well as the stored energy and the rotation of the lattice in the grains of the microstructure. At different steps of deformation, formation of subgrains, annihilation of dislocations, nucleation, growth and new orientation of grains are computed. The 3D aggregates representing the superalloy, are built up from Electron Back Scattered Diffraction method (EBSD) by means of a high resolution Scanning Electron Microscope. The phases are identified by means of EBSD, chemical analysis (EDS) and observations with a Scanning Electron Microscope. In this paper the studied aggregate is realised from a semi product of Udimet 720. Such technique is able to give us, a realistic description of the crystalline orientation, morphology and position of grains in the aggregate. The Finite Element meshing is deduced from the EBSD analysis. At high temperature, the Udimet 720 is constituted by a γ matrix with a Face Centred Cubic structure (FCC) and γ' precipitates (Ni3(Ti,Al)) with a Simple Cubic structure (SC). The various material parameters used for the coupled modelling are previously determined from compression tests performed at several strain rate and temperature; The dislocation densities are measured from Transmission Electronic Microscope.
Fichier principal
Vignette du fichier
revised_manuscript_superalloys2008_julien-thA_bault.pdf (777.45 Ko) Télécharger le fichier
sA_minaire_superalloys.pdf (1.59 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Format : Other

Dates and versions

hal-00783041 , version 1 (07-02-2013)


  • HAL Id : hal-00783041 , version 1


Julien Thébault, Denis Solas, Colette Rey, Thierry Baudin, Olivier Fandeur, et al.. POLYCRYSTALLINE MODELLING OF UDIMET 720 FORGING. TMS (The Minera, metal& material society) 2008. John Wiley&Sons Inc., pp.985-992, 2008, superalloys 2008, R.C. Reed, K. A. Green, P.C. Carron, T.P. Gabb, M. G. Fahrmann, E.S. Huron, S.A. Woodard. ⟨hal-00783041⟩
323 View
663 Download


Gmail Facebook Twitter LinkedIn More