Effect of pores on the fracture toughness of TiB{sub 2} / Si3N4 composites
- Noritake Co., Limited, Aichi (Japan)
Porosity was significantly increased in proportion to the amount of TiB{sub 2} particles, which were added to silicon nitride ceramics. The existence of TiN, detected by X-ray diffraction analysis and electron probe micro analysis, indicates that these pores were produced by the reaction between TiB{sub 2} particles and silicon nitride ceramics. The crack propagation was deflected at the interface between Si{sub 3}N{sub 4} matrix and TiB{sub 2} particles by the influence of residual stress, which was caused by the difference of thermal expansion coefficients. Also, it is worthy of notice that the crack propagation was restrained by the presence of pores. These phenomena significantly improved the fracture toughness up to 9.5 MPa{circ}m{sup 1/2} for the composite containing 10 vol% TiB{sub 2} particles. Other mechanical properties were also evaluated.
- OSTI ID:
- 518610
- Report Number(s):
- CONF-960367--
- Country of Publication:
- United States
- Language:
- English
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