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Key durability issues with mullite-based environmental barrier coatings for si-based ceramics
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Lee, Kang N. |
| Copyright Year | 1999 |
| Description | Plasma-sprayed mullite (3Al2O3 central dot 2SiO2) and mullite/yttria-stabilized-zirconia (YSZ) dual layer coatings have been developed to protect silicon-based ceramics from environmental attack. Mullite-based coating systems show excellent durability in air. However, in combustion environments, corrosive species such as molten salt or water vapor penetrate through cracks in the coating and attack the Si-based ceramics along the interface, Thus modification of the coating system for enhanced crack-resistance is necessary for long-term durability in combustion environments. Other key durability issues include interfacial contamination and coating/substrate bonding. Interfacial contamination leads to enhanced oxidation and interfacial pore formation, while weak coating/substrate bonding leads to rapid attack of the interface by corrosive species, both of which can cause premature failure of the coating. Interfacial contamination can be minimized by limiting impurities in coating and substrate materials. The interface may be modified to improve the coating/substrate bond. |
| File Size | 587778 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20000004334 |
| Archival Resource Key | ark:/13960/t0jt4m22v |
| Language | English |
| Publisher Date | 1999-01-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Service Life Mullites Molten Salts Durability Combustion Environment Protection Ceramics Substrates Contamination Silicon Compounds Cracks Penetration Corrosion Impurities Zirconium Oxides Yttria-stabilized Zirconia Oxidation Bonding Protective Coatings Yttrium Oxides Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
