Development of UHTCs and coatings on their basis for TPS applications
| Autor: | M. Parco, I. Fagoaga, L. Silvestroni, I. Belan, I. Neshpor, G.A. Frolov, M. Kütemeyer, T. Rheimer |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | WORKSHOP: State-of-the-Future Thermal Protection Systems for Reusable Space Vehicles, Berlin, GERMANY, June 1-4 2016 info:cnr-pdr/source/autori:M. Parco and I. Fagoaga, L. Silvestroni, I. Belan, I. Neshpor and G.A. Frolov, M. Kütemeyer and T. Rheimer/congresso_nome:WORKSHOP: State-of-the-Future Thermal Protection Systems for Reusable Space Vehicles/congresso_luogo:Berlin, GERMANY/congresso_data:June 1-4 2016/anno:2016/pagina_da:/pagina_a:/intervallo_pagine |
| Popis: | Thanks to their extremely high melting point above 3000°C and their unique combination of thermo-physical and engineering properties, ultra-high temperature ceramics (UHTCs) and coatings on their basis are envisaged as promising candidates for application at very high temperature. Among various compounds, ZrB2 has several advantages over other metal-based borides and carbides. One critical issue in the production of ZrB2-based ceramics is the achievement of fully dense bodies/coatings, which is the base-line condition to achieve good thermo-mechanical properties and oxidation resistance. Owing to the strong covalent bonds featuring all UHTCs, temperature above 2000°C and the application of pressure are required to densify these compounds. However, the microstructure deriving from such extreme processing conditions are coarse, with trapped porosity and hence with poor oxidation and mechanical performances. The addition of specific sintering additives has the twofold effect of decreasing the sintering temperatures down to 1650°C, and of notably modifying the performances at high temperature. One of the innovation brought by LIGHT-TPS consists in the investigation of new UHTC composites based on the ZrB2 that will be suitable for use at temperatures close to 2000°C under the conditions of thermo-erosive gas streams containing hard and liquid particles. Novel UHTC composites possessing improved thermo-mechanical properties and oxidation resistance will be employed as bulk, for use as components in the hottest parts of the spacecraft, and as coating, to protect and increase the durability of of C/C and C/SiC substrates. |
| Databáze: | OpenAIRE |
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