Imperial College London
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Dr Sam Humphry-Baker

Faculty of Engineering, Department of Materials

Lecturer in Ceramics
 
 
 
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Contact

 

s.humphry-baker

 
 
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Location

 

LM.04DRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Vreeswijk:2021:10.1016/j.ijrmhm.2021.105589,
author = {Vreeswijk, M and Kot, A and Giuliani, F and Humphry-Baker, S},
doi = {10.1016/j.ijrmhm.2021.105589},
journal = {International Journal of Refractory Metals and Hard Materials},
pages = {1--6},
title = {Abnormal WC crystal growth from liquid Co flux occurs via eta phase decomposition},
url = {http://dx.doi.org/10.1016/j.ijrmhm.2021.105589},
volume = {99},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The growth mechanism of large WC crystals from a liquid Co-based flux is identified. This is achieved by systematically varying the growth temperature and Co content from 1200 to 1400 °C and 70–83 at.% respectively. Crystal growth was characterised using metallography and X-ray diffraction. The WC grains were bimodally distributed, consisting of a smaller (10–20 μm) population of grains, which nucleated homogenously from the liquid, and a secondary population of abnormally large grains, several millimetres in size. The abnormal grains nucleated on the (W,Co)6C eta phase, and subsequently consumed it through a carburisation reaction. The size of abnormal grains was enhanced by adopting the eutectic composition, such that the first solid phase to form was the eta phase, whilst at the same time cooling slowly through the etaWC transformation temperature, at ~1300 °C. This growth mechanism could be exploited for a variety of metal carbides with similarly sluggish diffusion rates.
AU  - Vreeswijk,M
AU  - Kot,A
AU  - Giuliani,F
AU  - Humphry-Baker,S
DO  - 10.1016/j.ijrmhm.2021.105589
EP  - 6
PY  - 2021///
SN  - 0263-4368
SP  - 1
TI  - Abnormal WC crystal growth from liquid Co flux occurs via eta phase decomposition
T2  - International Journal of Refractory Metals and Hard Materials
UR  - http://dx.doi.org/10.1016/j.ijrmhm.2021.105589
UR  - https://www.sciencedirect.com/science/article/pii/S0263436821001219?via%3Dihub
UR  - http://hdl.handle.net/10044/1/89823
VL  - 99
ER  -
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