Microcracking in B{sub 4}C-TiB{sub 2} composites
- Elektroschmelzwerk Kempten GmbH (Germany)
- Lehrstuhl fuer Keramik und Verbundwerkstoffe, Bayreuth (Germany)
Boron carbide/titanium diboride composites with 20 and 40 vol% particulate TiB{sub 2} and various amounts of free carbon were investigated with respect to microcrack toughening. In agreement with previous work, the mere addition of TiB{sub 2} was found to raise the toughness from 2.2 MPa {center_dot} m{sup 1/2} up to 3.0 and 3.5 MPa {center_dot} m{sup 1/2}, respectively. A further and very significant increase of composite toughness up to 6.0 MPa {center_dot} m{sup 1/2} was discovered upon the incorporation of free carbon. SEM and TEM observations reveal that this toughening is associated with microcracking at B{sub 4}C-TiB{sub 2} phase boundaries. Microcracking is triggered by thin carbon interlayers, which are located at hetero interfaces and supply a weak fracture path.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 116091
- Journal Information:
- Journal of the American Ceramic Society, Vol. 78, Issue 9; Other Information: PBD: Sep 1995
- Country of Publication:
- United States
- Language:
- English
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