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Thermal stability of hi-nicalon sic fiber in nitrogen and silicon environments
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Bhatt, R. T. Garg, A. |
| Copyright Year | 1995 |
| Description | The room temperature tensile strength of uncoated and two types of pyrolytic boron nitride coated (PBN and Si-rich PBN) Hi-Nicalon SiC fibers was determined after 1 to 400 hr heat treatments to 1800 C under N2 pressures of 0.1, 2, and 4 MPa, and under 0.1 Mpa argon and vacuum environments. In addition, strength stability of both uncoated and coated fibers embedded in silicon powder and exposed to 0.1 MPa N2 for 24 hrs at temperatures to 1400 C was investigated. The uncoated and both types of BN coated fibers exposed to N2 for 1 hr showed noticeable strength degradation above 1400 C and 1600 C, respectively. The strength degradation appeared independent of nitrogen pressure, time of heat treatment, and surface coatings. TEM microstructural analysis suggests that flaws created due to SiC grain growth are responsible for the strength degradation. In contact with silicon powder, the uncoated and both types of PBN coated fibers degrade rapidly above 1350 C. |
| File Size | 8567440 |
| Page Count | 10 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19960009430 |
| Archival Resource Key | ark:/13960/t5hb42b3j |
| Language | English |
| Publisher Date | 1995-09-01 |
| Access Restriction | Open |
| Subject Keyword | Inorganic And Physical Chemistry Heat Treatment Pressure Effects Ceramic Fibers Boron Nitrides Silicon Carbides Coatings Nitrogen Tensile Strength Thermal Stability Fiber Strength Temperature Effects Reinforcing Fibers Silicon Microstructure Thermal Degradation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
