2009 | |
Articles: | |
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Computational Material Science,
46(3):761-766
2009
ISSN: 0927-0256
Resume: A multiphase model for Ti-6Al-4V is proposed. This material is widely used in industrial applications and so needs accurate behaviour modeling. Tests have been performed in the temperature range from 25 degrees C to 1020 degrees C and at strain rates between 10(-3) s(-1) and 1 s(-1). This allowed the identification of a multiphase mechanical model coupled with a metallurgical model. The behaviour of each phase is calibrated by solving an inverse problem including a phase transformation model and a mechanical model to simulate tests under thermomechanical loadings. A scale transition rule (beta-rule) is proposed in order to represent the redistribution of local stresses linked to the heterogeneity of plastic strain. Finally this model is applied to two laser assisted processes: direct laser fabrication and laser welding. (C) 2009 Elsevier B.V. All rights reserved. Equipe: Département SI2M : Microstructures et Contraintes |
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European Journal of Computational Mechanics,
18(5-6):485-523
2009
ISSN: 1779-7179
Equipe: Département SI2M : Microstructures et Contraintes |
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Computational Materials Science,
45(3):800-805
2009
ISSN: 0927-0256
Equipe: Département SI2M : Microstructures et Contraintes |
2007 | |
Articles: | |
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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,
448(1-2):135-145
2007
ISSN: 0921-5093
Resume: We have investigated the microstructure evolutions in the Ti17 near beta titanium alloy during heat treatments. The phase transformation has first been studied experimentally by combining X-ray diffraction analysis, electrical resistivity and microscopy observations. From a series of isothermal treatments. a IT diauram has been determined, which takes into account the different morphologies. Then, a Johnson-Mehl-Avrami-Kolmogorov (JMAK) model has been successfully used to describe the phase transformation kinetics during either isothermal or cooling treatments. Finally, the coupling of the JMAK model to the finite element software ZeBuLoN allowed us to investigate the evolution of the spatial distribution of the different morphologies during the cooling of an aircraft engine shaft disk after forging. (c) 2006 Elsevier B.V. All rights reserved. Equipe: Département SI2M : Microstructures et Contraintes |