Imperial College London
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ProfessorDavidDye

Faculty of Engineering, Department of Materials

Professor of Metallurgy
 
 
 
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Contact

 

+44 (0)20 7594 6811david.dye

 
 
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Location

 

1.09GoldsmithSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Dear:2021:10.1016/j.actamat.2021.116811,
author = {Dear, FF and Kontis, P and Gault, B and Ilavsky, J and Rugg, D and Dye, D},
doi = {10.1016/j.actamat.2021.116811},
journal = {Acta Materialia},
title = {Mechanisms of Ti3Al precipitation in hcp α-Ti},
url = {http://dx.doi.org/10.1016/j.actamat.2021.116811},
volume = {212},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Nucleation  and  growth  of  Ti3Alα2ordered  domains  inα-Ti–Al–X  alloys  were  characterised  using  a  combination  of  transmission  electronmicroscopy,  atom probe tomography and small angle X-ray scattering.   Model alloys based on Ti–7Al (wt.%) and containing O, V and Mowere  aged  at  550C  for  times  up  to  120 d  and  the  resulting  precipitate  dispersions  were  observed  at  intermediate  points.   Precipitates  grewto around 30 nm in size, with a volume fraction of 6–10% depending on tertiary solutes.  Interstitial O was found to increase the equilibriumvolume fraction ofα2, while V and Mo showed relatively little influence.  Addition of any of the solutes in this study, but most prominentlyMo, was found to increase nucleation density and decrease precipitate size and possibly coarsening rate.  Coarsening can be described by theLifshitz-Slyozov-Wagner model, suggesting a matrix diffusion-controlled coarsening mechanism (rather than control by interfacial coherency).Solutionising temperature was found to affect nucleation number density with an activation energy ofEf=1.5±0.4 eV, supporting the hypothesisthat vacancy concentration affectsα2nucleation.  The observation that all solutes increase nucleation number density is also consistent with avacancy-controlled nucleation mechanism.
AU  - Dear,FF
AU  - Kontis,P
AU  - Gault,B
AU  - Ilavsky,J
AU  - Rugg,D
AU  - Dye,D
DO  - 10.1016/j.actamat.2021.116811
PY  - 2021///
SN  - 1359-6454
TI  - Mechanisms of Ti3Al precipitation in hcp α-Ti
T2  - Acta Materialia
UR  - http://dx.doi.org/10.1016/j.actamat.2021.116811
UR  - https://www.sciencedirect.com/science/article/pii/S1359645421001919?via%3Dihub
UR  - http://hdl.handle.net/10044/1/87387
VL  - 212
ER  -
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