Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties
Ceramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made of Hi-Nicalon S fibers was densified by a matrix composed of Si<sub>2</sub>N<sub>2</sub>O prepared inside the CMC by reacting a mixture of...
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doaj-4de432669d954bfa9eaa5c7d9bfd67c62021-07-23T13:48:27ZengMDPI AGJournal of Composites Science2504-477X2021-07-01517917910.3390/jcs5070179Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials PropertiesBrice Taillet0René Pailler1Francis Teyssandier2Laboratoire des Composites ThermoStructuraux (LCTS), UMR 5801, CNRS, CEA, Safran, Université de Bordeaux, 33600 Pessac, FranceLaboratoire des Composites ThermoStructuraux (LCTS), UMR 5801, CNRS, CEA, Safran, Université de Bordeaux, 33600 Pessac, FranceLaboratoire des Composites ThermoStructuraux (LCTS), UMR 5801, CNRS, CEA, Safran, Université de Bordeaux, 33600 Pessac, FranceCeramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made of Hi-Nicalon S fibers was densified by a matrix composed of Si<sub>2</sub>N<sub>2</sub>O prepared inside the CMC by reacting a mixture of Si and SiO<sub>2</sub> under high nitrogen pressure. This part describes the oxidation resistance and mechanical properties of the optimized CMC. The CMC submitted to oxidation in wet oxygen at 1400 °C for 170 h exhibited an oxidation gradient from the surface to almost the center of the sample. In the outer part of the sample, Si<sub>2</sub>N<sub>2</sub>O, Si<sub>3</sub>N<sub>4</sub> and SiC were oxidized into silica in the cristobalite-crystallized form. The matrix microstructure looks similar to the original one at the center of the sample, while at the surface large pores are observed and the fiber/matrix interphase is consumed by oxidation. The elastic modulus and the hardness measured at room temperature by nano-indentation are, respectively, 100 and 8 GPa. The elastic modulus measured at room temperature by tensile tests ranges from 150 to 160 GPa and the ultimate yield strength from 320 to 390 MPa, which corresponds to a yield strain of about 0.6%. The yield strength identified by acoustic emission is about 40 MPa.https://www.mdpi.com/2504-477X/5/7/179ceramic matrix compositecorrosion and oxidationmechanical testing |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Brice Taillet René Pailler Francis Teyssandier |
spellingShingle |
Brice Taillet René Pailler Francis Teyssandier Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties Journal of Composites Science ceramic matrix composite corrosion and oxidation mechanical testing |
author_facet |
Brice Taillet René Pailler Francis Teyssandier |
author_sort |
Brice Taillet |
title |
Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties |
title_short |
Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties |
title_full |
Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties |
title_fullStr |
Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties |
title_full_unstemmed |
Densification of Ceramic Matrix Composite Preforms by Si<sub>2</sub>N<sub>2</sub>O Formed by Reaction of Si with SiO<sub>2</sub> under High Nitrogen Pressure. Part 2: Materials Properties |
title_sort |
densification of ceramic matrix composite preforms by si<sub>2</sub>n<sub>2</sub>o formed by reaction of si with sio<sub>2</sub> under high nitrogen pressure. part 2: materials properties |
publisher |
MDPI AG |
series |
Journal of Composites Science |
issn |
2504-477X |
publishDate |
2021-07-01 |
description |
Ceramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made of Hi-Nicalon S fibers was densified by a matrix composed of Si<sub>2</sub>N<sub>2</sub>O prepared inside the CMC by reacting a mixture of Si and SiO<sub>2</sub> under high nitrogen pressure. This part describes the oxidation resistance and mechanical properties of the optimized CMC. The CMC submitted to oxidation in wet oxygen at 1400 °C for 170 h exhibited an oxidation gradient from the surface to almost the center of the sample. In the outer part of the sample, Si<sub>2</sub>N<sub>2</sub>O, Si<sub>3</sub>N<sub>4</sub> and SiC were oxidized into silica in the cristobalite-crystallized form. The matrix microstructure looks similar to the original one at the center of the sample, while at the surface large pores are observed and the fiber/matrix interphase is consumed by oxidation. The elastic modulus and the hardness measured at room temperature by nano-indentation are, respectively, 100 and 8 GPa. The elastic modulus measured at room temperature by tensile tests ranges from 150 to 160 GPa and the ultimate yield strength from 320 to 390 MPa, which corresponds to a yield strain of about 0.6%. The yield strength identified by acoustic emission is about 40 MPa. |
topic |
ceramic matrix composite corrosion and oxidation mechanical testing |
url |
https://www.mdpi.com/2504-477X/5/7/179 |
work_keys_str_mv |
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