Simulation numérique multi-échelles du comportement mécanique des alliages de titane bêta-métastable Ti5553 et Ti17

Abstract : The purpose of this PhD work is to investigate deformation mechanisms at room temperature in beta-metastable titanium alloys Ti17 and Ti5553. Studied microstructures are composed of beta-grains, in which alpha phase can precipitate under twelve different variants according to Burgers relationship. A multiscale approach is then proposed with three levels to consider: macroscopic, mesoscopic (prior beta grains) and microscopic (alpha variants and beta matrix of each grain). Different mean field models are adapted to depict Ti17 and Ti5553 mechanical behaviors. These models are based on the two scale-transition homogenization of local behaviors, with various ways of representing intergranular interactions. Relationships between microstructures and mechanical properties are also considered. The most advanced micromechanical models developed in this work depict elastic anisotropy and viscoplastic flow of each hcp alpha variant and each bcc beta matrix, using crystal plasticity with kinematic and isotropic hardening. Identification of material parameters is done using a large experimental database from PROMITI project. To understand the role of each phase in the deformation process, a FE computation was also made to reproduce the uniaxial tensile test of a very thick micro-specimen. In this study, the mesoscopic scale is explicitly represented: each beta grain has a real geometry and crystallographic orientation, according to a measured EBSD map in SEM. Comparisons between experiment and the numerical simulation are made on macroscopic stress - strain curves as well as on the mesoscopic scale, by considering out-of-plane displacement and strain fields.
Document type :
Theses
Complete list of metadatas

Cited literature [34 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/pastel-00873129
Contributor : Abes Star <>
Submitted on : Tuesday, October 15, 2013 - 10:27:30 AM
Last modification on : Monday, November 12, 2018 - 10:55:09 AM
Long-term archiving on : Thursday, January 16, 2014 - 5:10:54 AM

File

2012ENMP0099.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : pastel-00873129, version 1

Citation

Guillaume Martin. Simulation numérique multi-échelles du comportement mécanique des alliages de titane bêta-métastable Ti5553 et Ti17. Autre. Ecole Nationale Supérieure des Mines de Paris, 2012. Français. ⟨NNT : 2012ENMP0099⟩. ⟨pastel-00873129⟩

Share

Metrics

Record views

1337

Files downloads

1685