SiC and Si{sub 3}N{sub 4} fibrous monoliths: Non-brittle fracture from powder processed ceramics produced by coextrusion
- Univ. of Michigan, Ann Arbor, MI (United States)
Fibrous monoliths are non-brittle ceramics which are fabricated by powder processing techniques using novel methods to produce a fibrous texture. As a group of materials, fibrous monolithic ceramics [FM`s] are extremely flaw tolerant and exhibit graceful failure, retaining significant load bearing ability after fracture begins. Weak interface fibrous monoliths fracture like wood, with graceful failure occurring by shear delamination. Si{sub 3}N{sub 4}/BN fibrous monoliths have apparent flexural strengths around 300 MPa and retain about half of their load bearing ability after the first fracture event occurs, with apparent inelastic fracture energies around 2500 J/m{sup 2}. SiC-Based/BN fibrous monoliths have apparent flexural strengths as high as 370 MPa at room temperature with 90-100% of the room temperature strength retained out to 1500{degrees}C. Graceful failures are again observed in this system with inelastic fracture energies around 1000 J/M{sup 2} at all temperatures. We will discuss processing and mechanical properties of fibrous monoliths made by {open_quotes}single filament{close_quotes} coextrusion.
- OSTI ID:
- 99180
- Report Number(s):
- CONF-940911--
- Country of Publication:
- United States
- Language:
- English
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