Imperial College London
Alternate

ProfessorFionnDunne

Faculty of Engineering, Department of Materials

Principal Research Fellow
 
 
 
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Contact

 

+44 (0)20 7594 2884fionn.dunne

 
 
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Location

 

104Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Zhang:2017:10.1016/j.jmps.2017.03.012,
author = {Zhang, Z and Dunne, FPE},
doi = {10.1016/j.jmps.2017.03.012},
journal = {Journal of the Mechanics and Physics of Solids},
pages = {199--220},
title = {Microstructural heterogeneity in rate-dependent plasticity of multiphase titanium alloys},
url = {http://dx.doi.org/10.1016/j.jmps.2017.03.012},
volume = {103},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Polycrystalline rate-dependent plasticity is found to originate from heterogeneous slip system/phase rate response. Micro-mechanism under low stress and low temperature (T < 0.3Tm) has been shown to be different from conventional rate sensitivity expectations. Hence the constitutive framework developed is dependent on the crystallographic orientation, properly capturing micro-scale anisotropic rate behaviour.The intrinsic rate anisotropy of the HCP α prism and basal and BCC β phase slip systems in Ti-6242, recently determined from micro-pillar and crystal plasticity modelling, have been utilised to investigate the structural strain rate sensitivities of colonies, polycrystals, bimodal and basket weave microstructures.The rate sensitivity of colony structures is dominated by the HCP α phase behaviour, at least for alloys containing up to ∼20% volume fraction β phase, and is largely independent of β-lath orientation. The apparent anisotropy of a1, a2 and a3 basal resolved shear stresses in Ti-6242 colonies is shown to originate from the local crystal stress states established as opposed to the α−β interfaces.Texture and α−β morphology are shown to affect rate dependence and to corroborate that the basal rate sensitivity is stronger than that for prism slip in Ti-6242. Morphological effects are shown to affect rate dependence but not strongly, but the number of HCP α phase variants in basketweave structures is found to have a significant effect with higher numbers of variants leading to lower strain rate sensitivities. This is potentially important in designing alloys to resist cold dwell fatigue.
AU  - Zhang,Z
AU  - Dunne,FPE
DO  - 10.1016/j.jmps.2017.03.012
EP  - 220
PY  - 2017///
SN  - 1873-4782
SP  - 199
TI  - Microstructural heterogeneity in rate-dependent plasticity of multiphase titanium alloys
T2  - Journal of the Mechanics and Physics of Solids
UR  - http://dx.doi.org/10.1016/j.jmps.2017.03.012
UR  - http://hdl.handle.net/10044/1/45772
VL  - 103
ER  -
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