Zirconium carbide oxidation: kinetics and oxygen diffusion through the intermediate layer

File Description SizeFormat 
Gasparrini_et_al-2018-Journal_of_the_American_Ceramic_Society.pdfPublished version2.74 MBAdobe PDFDownload
Title: Zirconium carbide oxidation: kinetics and oxygen diffusion through the intermediate layer
Author(s): Gasparrini, C
Chater, RJ
Horlait, D
Vandeperre, L
Lee, WE
Item Type: Journal Article
Abstract: Oxidation of hot‐pressed ZrC was investigated in air in the 1073‐1373 K range. The kinetics were linear at 1073 K, whereas at higher temperature samples initially followed linear kinetics before undergoing rapid oxidation leading to a Maltese cross shape of the oxide. The linear kinetics at 1073 K was governed by inward oxygen diffusion through an intermediate layer of constant thickness between ZrC and ZrO2 which was comprised of amorphous carbon and ZrO2 nanocrystals. Diffusion of oxygen through the intermediate layer was measured to be 9 × 10−10 cm2 s−1 using 18O as a tracer in a double oxidation experiment in 16O/18O. Oxidation at 1073 and 1173 K produced samples made of m‐ZrO2 and either t‐ or c‐ZrO2 with an adherent intermediate layer made of amorphous carbon and ZrO2, whereas oxidation at 1273 and 1373 K produced samples with a voluminous oxide made of m‐ZrO2 showing a gap between ZrC and the oxide. A substoichiometric zirconia layer was found at the gap at 1273 K and no carbon uptake was detected in this layer when compared with the top oxide layer. The loss of the intermediate layer and the slowdown of the linear rate constant (g m−2 s−1) at 1273 K compared to 1173 K was correlated with the preferential oxidation of carbon at the intermediate layer which would leave as CO and/or CO2 leaving a gap between ZrC and substoichiometric zirconia.
Publication Date: 1-Jun-2018
Date of Acceptance: 1-Feb-2018
URI: http://hdl.handle.net/10044/1/56721
DOI: https://dx.doi.org/10.1111/jace.15479
ISSN: 0002-7820
Publisher: Wiley
Start Page: 2638
End Page: 2652
Journal / Book Title: Journal of the American Ceramic Society
Volume: 101
Issue: 6
Sponsor/Funder: Defence Science and Technology Laboratory (DSTL)
Engineering & Physical Science Research Council (EPSRC)
Engineering and Physical Sciences Research Council
Engineering and Physical Sciences Research Council
Funder's Grant Number: DSTLX-1000085783
EP/M018563/1
EP/L014041/1
EP/M507428/1
Copyright Statement: © 2018 The Authors. Journal of the American Ceramic Society published by Wiley Periodicals, Inc. on behalf of American Ceramic Society (ACERS) This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Keywords: Science & Technology
Technology
Materials Science, Ceramics
Materials Science
oxidation
zirconia
zirconium
zirconium compounds
METASTABLE TETRAGONAL PHASE
SINGLE-CRYSTALS
IN-SITU
STABILIZED ZIRCONIA
ZRC/ZRO2 INTERFACE
POWDER DIFFRACTION
CERAMIC MATERIALS
ROOM-TEMPERATURE
METAL OXIDATION
CARBON
0912 Materials Engineering
0913 Mechanical Engineering
Materials
Publication Status: Published
Online Publication Date: 2018-02-08
Appears in Collections:Faculty of Engineering
Materials
Faculty of Natural Sciences



Items in Spiral are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commons