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Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures
Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well as thermo-mechanical environments, internal stresses and microcracking are often present in such materials under operating conditions (sometimes in excess of 1700 °C)....
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479750/ https://www.ncbi.nlm.nih.gov/pubmed/30934787 http://dx.doi.org/10.3390/ma12071017 |
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author | Laquai, René Gouraud, Fanny Müller, Bernd Randolf Huger, Marc Chotard, Thierry Antou, Guy Bruno, Giovanni |
author_facet | Laquai, René Gouraud, Fanny Müller, Bernd Randolf Huger, Marc Chotard, Thierry Antou, Guy Bruno, Giovanni |
author_sort | Laquai, René |
collection | PubMed |
description | Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well as thermo-mechanical environments, internal stresses and microcracking are often present in such materials under operating conditions (sometimes in excess of 1700 °C). We studied the evolution of thermal (CTE) and mechanical (Young’s modulus) properties as a function of temperature in a fused-cast refractory containing 94 wt.% of monoclinic ZrO(2) and 6 wt.% of a silicate glassy phase. With the aid of X-ray refraction techniques (yielding the internal specific surface in materials), we also monitored the evolution of microcracking as a function of thermal cycles (crossing the martensitic phase transformation around 1000 °C) under externally applied stress. We found that external compressive stress leads to a strong decrease of the internal surface per unit volume, but a tensile load has a similar (though not so strong) effect. In agreement with existing literature on β-eucryptite microcracked ceramics, we could explain these phenomena by microcrack closure in the load direction in the compression case, and by microcrack propagation (rather than microcrack nucleation) under tensile conditions. |
format | Online Article Text |
id | pubmed-6479750 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-64797502019-04-29 Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures Laquai, René Gouraud, Fanny Müller, Bernd Randolf Huger, Marc Chotard, Thierry Antou, Guy Bruno, Giovanni Materials (Basel) Article Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well as thermo-mechanical environments, internal stresses and microcracking are often present in such materials under operating conditions (sometimes in excess of 1700 °C). We studied the evolution of thermal (CTE) and mechanical (Young’s modulus) properties as a function of temperature in a fused-cast refractory containing 94 wt.% of monoclinic ZrO(2) and 6 wt.% of a silicate glassy phase. With the aid of X-ray refraction techniques (yielding the internal specific surface in materials), we also monitored the evolution of microcracking as a function of thermal cycles (crossing the martensitic phase transformation around 1000 °C) under externally applied stress. We found that external compressive stress leads to a strong decrease of the internal surface per unit volume, but a tensile load has a similar (though not so strong) effect. In agreement with existing literature on β-eucryptite microcracked ceramics, we could explain these phenomena by microcrack closure in the load direction in the compression case, and by microcrack propagation (rather than microcrack nucleation) under tensile conditions. MDPI 2019-03-27 /pmc/articles/PMC6479750/ /pubmed/30934787 http://dx.doi.org/10.3390/ma12071017 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Laquai, René Gouraud, Fanny Müller, Bernd Randolf Huger, Marc Chotard, Thierry Antou, Guy Bruno, Giovanni Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title | Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title_full | Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title_fullStr | Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title_full_unstemmed | Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title_short | Evolution of Thermal Microcracking in Refractory ZrO(2)-SiO(2) after Application of External Loads at High Temperatures |
title_sort | evolution of thermal microcracking in refractory zro(2)-sio(2) after application of external loads at high temperatures |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479750/ https://www.ncbi.nlm.nih.gov/pubmed/30934787 http://dx.doi.org/10.3390/ma12071017 |
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