Imperial College London
Alternate

DrMarkWenman

Faculty of Engineering, Department of Materials

Reader in Nuclear Materials
 
 
 
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Contact

 

+44 (0)20 7594 6763m.wenman

 
 
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Location

 

B301aRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{King:2020:10.1016/j.actamat.2019.11.007,
author = {King, DJM and Yang, M and Whiting, TM and Liu, X and Wenman, MR},
doi = {10.1016/j.actamat.2019.11.007},
journal = {Acta Materialia},
pages = {350--361},
title = {G-phase strengthened iron alloys by design},
url = {http://dx.doi.org/10.1016/j.actamat.2019.11.007},
volume = {183},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Density functional theory (DFT) calculations were used to model G-phase precipitates of formula X6M16Si7 where X is Cr, Hf, Mn, Mo, Nb, Ta, Ti, V, W and Zr and M is either Fe or Ni. It was found that the occupancy of the d-orbital is correlated to the formation enthalpies of each structure. Past thermal expansion coefficient data was used to predict the lattice misfit between each G-phase and body centred cubic (BCC) Fe. All except Hf and Zr containing G-phases were predicted to have zero misfit between 581−843 K. Of the Ni containing G-phases, Mn6Ni16Si7 was predicted to have the most similar elastic properties to BCC Fe. DFT calculations of the substitution energies of Al, Cr Cu, Fe, Ge, Hf, Mo, Nb, P, Ta, Ti, V, Zr, and vacancies onto the Mn6Ni16Si7 G-phase from BCC Fe were performed. It was predicted that Cu, P and vacancies favour G-phase substitution. Suppression of the G-phase is predicted when Si content is reduced by half, at which point the BCC phase is favoured. It is hypothesised that including Zr to form a (Mn,Zr)6Ni16Si7 precipitate will allow for higher ageing temperature and expediate nucleation in an Fe alloy. Thermocalc was used to predict that a mixture of FebalCr9Ni4Si2(Mn0.6Zr0.4)1.2 (at.%) will produce a G-phase strengthened Fe alloy with potential for a good balance of strength, ductility and oxidation/corrosion resistance at room temperature. This alloy composition was experimentally determined to precipitate the G-phase in ≤24 h with cube-on-cube orientation to the BCC Fe matrix.
AU  - King,DJM
AU  - Yang,M
AU  - Whiting,TM
AU  - Liu,X
AU  - Wenman,MR
DO  - 10.1016/j.actamat.2019.11.007
EP  - 361
PY  - 2020///
SN  - 1359-6454
SP  - 350
TI  - G-phase strengthened iron alloys by design
T2  - Acta Materialia
UR  - http://dx.doi.org/10.1016/j.actamat.2019.11.007
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000506465100030&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/80015
VL  - 183
ER  -
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