Electrochemical Study of a Pendant Molten Alumina Droplet and Its Application for Thermodynamic Property Measurements of Al-Ir
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nak17.pdf
Description
Published version
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3.3 MB
Format
Adobe PDF
Checksum (MD5)
a09963f4890c14dfd3f0307d6d31a312
Author(s)
Nakanishi, Bradley Rex
Allanore, Antoine
Date Issued
October 2017
Journal
Journal of The Electrochemical Society
Publisher
The Electrochemical Society
Citation
Nakanishi, Bradley R. and Antoine Allanore, "Electrochemical Study of a Pendant Molten Alumina Droplet and Its Application for Thermodynamic Property Measurements of Al-Ir." Journal of The Electrochemical Society 164, 13 (October 2017): E460-E471 doi. 10.1149/2.1091713jes © 2017 Authors
Version
Final published version
Abstract
Limited knowledge of the thermodynamic and transport properties of refractory materials in the liquid state remains a key challenge limiting their application. Using alternating current (AC) and direct current (DC) techniques, the electrochemical kinetics of oxygen evolution and metal deposition was investigated in a pendant droplet of molten alumina (Al2O3) with three iridium (Ir) electrodes in a thermal imaging furnace. For the first time, the direct electrolytic decomposition of molten Al2O3 to oxygen gas and aluminum (Al) metal (alloyed with Ir) was observed, confirming the ionic nature of molten Al2O3. The decomposition potential of molten Al2O3 was measured with high precision using AC voltammetry, and the results demonstrated remarkable sensitivity to variation in temperature enabling measurement of chemical potential and entropy of Al at the Ir-rich solid-liquid phase boundary for the first time. The results were in remarkably close agreement with the most recent thermodynamic assessment of the Al-Ir system. ©The Author(s) 2017. Published by ECS. All rights reserved.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
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Creative Commons Attribution-NonCommercial-NoDerivs License
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DOI of Published Version
https://doi.org/10.1149/2.1091713JES
