Micromechanical phase-field model and simulation of eutectic growth with misfit stresses

Precise understanding of eutectic solidification and its controlling parameters is crucial in characterizing of many metal products. Numerical simulations are required to predict the formation of eutectic lamellae and the resulting microstructure which, in turn, determines the macroscopic mechanical properties of casting alloys. In this work, we aim to develop a micromechanical phase-field model to assess the eutectic solidification in alloys with coherent elastic misfit. First, we generalize an existing phase-field method of diffusion-limited two-phase growth [Phys. Rev. E, 70 (2004) 061604] to a model of free-volume eutectic growth with coupled heat and solute diffusion. Secondly, we develop an elastic phase-field model based on linear microelasticity theory by considering elastic inhomogeneity to incorporate the elastic interactions arising from the mismatch between coherent phases in eutectic growth. Next, we apply the elastic phase-field model to an organic alloy by assuming isotropic elasticity and evaluate the corresponding stress and strain distributions. Moreover, we generalize our elastic model to consider the anisotropy in materials. The effect of the thermal gradient and the local undercooling are also studied to understand the occurrence of lamellae in directional and free-volume eutectic growth in Ti-Fe alloys. Finally, we extend the elastic phase-field model to multiple orientations for a limited number of eutectic nuclei.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2010

Author dc:creator

• Ebrahimi, Zohreh

Contributors dc:contributor

• Bührig-Polaczek, Andreas

• info:eu-repo/classification/ddc/620
• Phasenfeldmodell
• Erstarrung
• Binäre Legierung
• Titanlegierung
• Ingenieurwissenschaften
• eutektischen Wachstums
• elastischer Gitterfehlanpassung
• elastische Phasenfeldmodell
• eutectic growth
• phase-field model
• misfit stress
• elastic energy

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113167%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A50631