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Paralinear oxidation of silicon nitride in a water vapor/oxygen environment
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Nguyen, QuynhGiao Humphrey, Donald L. Fox, Dennis S. Opila, Elizabeth J. Lewton, Susan M. |
| Copyright Year | 2002 |
| Description | Three silicon nitride materials were exposed to dry oxygen flowing at 0.44 cm/s at temperatures between 1200 and 1400 C. Reaction kinetics were measured with a continuously recording microbalance. Parabolic kinetics were observed. When the same materials were exposed to a 50% H2O - 50% O2 gas mixture flowing at 4.4 cm/s, all three types exhibited paralinear kinetics. The material is oxidized by water vapor to form solid silica. The protective silica is in turn volatilized by water vapor to form primarily gaseous Si(OH)4. Nonlinear least squares analysis and a paralinear kinetic model were used to determine both parabolic and linear rate constants from the kinetic data. Volatilization of the protective silica scale can result in accelerated consumption of Si3N4. Recession rates under conditions more representative of actual combustors are compared to the furnace data. |
| File Size | 21750189 |
| Page Count | 45 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20020072851 |
| Archival Resource Key | ark:/13960/t8qc4zx7w |
| Language | English |
| Publisher Date | 2002-01-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Oxygen Reaction Kinetics Silicon Nitrides Nonlinearity Oxidation Water Vapor Silicon Dioxide Drying Gas Mixtures Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
