Multilayer interface tracking model of pure tungsten oxidation

Huang, Shu and Kerr, Ryan and Murphy, Samuel T and Gilbert, Mark R and Marian, Jaime (2022) Multilayer interface tracking model of pure tungsten oxidation. Modelling and Simulation in Materials Science and Engineering, 30 (8). ISSN 0965-0393

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Abstract

We present a numerical model to predict oxide scale growth on tungsten surfaces under exposure to oxygen at high temperatures. The model captures the formation of four thermodynamically-compatible oxide sublayers, WO2, WO2.72, WO2.9, and WO3, on top of the metal substrate. Oxide layer growth is simulated by tracking the oxide/oxide and oxide/metal interfaces using a sharp-interface Stefan model coupled to diffusion kinetics. The model is parameterized using selected experimental measurements and electronic structure calculations of the diffusivities of all the oxide subphases involved. We simulate oxide growth at temperatures of 600∘C and above, extracting the power law growth exponents in each case, which we find to deviate from classical parabolic growth in several cases. We conduct a comparison of the model predictions with an extensive experimental data set, with reasonable agreement at most temperatures. While many gaps in our understanding still exist, this work is a first attempt at embedding the thermodynamic and kinetic complexity of tungsten oxide growth into a comprehensive mesoscale kinetic model that attempts to capture the essential features of tungsten oxidation to fill existing knowledge gaps and guide and enhance future tungsten oxidation models.

Item Type:
Journal Article
Journal or Publication Title:
Modelling and Simulation in Materials Science and Engineering
Additional Information:
This is an author-created, un-copyedited version of an article accepted for publication/published in Modelling and Simulation in Materials Science and Engineering. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1361-651X/aca111
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3104
Subjects:
ID Code:
181272
Deposited By:
Deposited On:
22 Dec 2022 15:20
Refereed?:
Yes
Published?:
Published
Last Modified:
22 Dec 2022 15:20