Transport properties of ceramic composites
- Georgia Institute of Technology, Atlanta, GA (United States)
Instrumentation and procedures have been completed for measurement of gas permeability and mass diffusivity of fiber preforms and porous materials. Results are reported for composites reinforced with Nicalon fiber in cloth lay-up and 3-D weave and with Nextel fiber in multi-layer braid. Measured permeability values range from near 100 to less than 0.1 darcies. Mass diffusivity is reported as a structure factor relating the diffusion through the porous material to that in free space. This measure is independent of the diffusing species and depends only on the pore structure of the material. Measurements are compared to predictions of a node-bond model for gas transport. Model parameters adjusted to match measured transport properties relate to physical microstructure features of the different architectures. Combination of this transport model with the CVI process model offers a predictive method to evaluate the densification behavior of various fiber preforms.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 492111
- Report Number(s):
- ORNL/FMP-96/1; CONF-9605167-; ON: DE97050349; TRN: 97:001933-0002
- Resource Relation:
- Conference: 10. annual conference on fossil energy materials, Knoxville, TN (United States), 14-16 May 1996; Other Information: PBD: Aug 1996; Related Information: Is Part Of Proceedings of the tenth annual conference on fossil energy materials; Cole, N.C.; Judkins, R.R. [comps.]; PB: 551 p.
- Country of Publication:
- United States
- Language:
- English
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