Crystal plasticity analysis of deformation anisotropy of lamellar TiAl alloy: 3D microstructure-based modelling and in-situ micro-compression
File(s)Crystal plasticity of TiAl-Accepted.pdf (2.4 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Detailed microstructure characterisation and in-situ micropillar compression were coupled with crystal plasticity-based finite element modelling (CP-FEM) to study the micro-mechanisms of plastic anisotropy in lamellar TiAl alloys. The consideration of microstructure in both simulation and in-situ experiments enables in-depth understanding of micro-mechanisms responsible for the highly anisotropic deformation response of TiAl on the intra-lamella and inter-lamella scales. This study focuses on two specific configurations of lamellar microstructure with the interfaces being aligned and to the loading direction. Microstructure-based CP-FEM shows that longituginal slip of super and ordinary dislocations are most responsible for the plastic anisotropy in the micropillar while the anisotropy of the micropillar is due to longitudinal superdislocations and longitudinal twins. In addition, transversal superdislocations were more active, making the deformation in the micropillar less localised than that in the micropillar. Moreover, the CP-FEM model successfully predicted substantial build-up of internal stresses at interfaces, which is believed to be detrimental to the ductility in TiAl. However, as evidenced by the model, the detrimental internal stresses can be significantly relieved by the activation of transverse deformation twinning, suggesting that the ductility of TiAl can be improved by promoting transverse twins.
Date Issued
2019-08-01
Online Publication Date
2020-04-23T06:00:20Z
Date Acceptance
2019-04-19
ISSN
0749-6419
Publisher
Elsevier
Start Page
344
End Page
360
Journal / Book Title
International Journal of Plasticity
Volume
119
Issue
1
Copyright Statement
© 2019 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.sciencedirect.com/science/article/pii/S0749641919300026
Subjects
Science & Technology
Technology
Engineering, Mechanical
Materials Science, Multidisciplinary
Mechanics
Engineering
Materials Science
Titanium aluminide
Lamellar
Crystal plasticity
Anisotropy
Twinning
POLYSYNTHETICALLY TWINNED CRYSTALS
HIGH-TEMPERATURE
SINGLE-CRYSTALS
MECHANICAL-BEHAVIOR
TEXTURE DEVELOPMENT
PST CRYSTALS
FRACTURE
COMPOUND
FATIGUE
SLIP
Mechanical Engineering & Transports
0905 Civil Engineering
0912 Materials Engineering
0913 Mechanical Engineering
Publication Status
Published
Date Publish Online
2019-04-23