Sintering ZrO{sub 2}/TiC composites with TiH{sub 2}: The role of transient liquid phase and of substoichiometry
- Fraunhofer Inst. for Ceramic Technologies and Sintered Materials, Dresden (Germany)
- Max-Planck-Inst. for the Physics of Microstructures, Halle (Germany)
Sintering tetragonal ZrO{sub 2} with 35 vol% TiC results in a microstructure where all grain facets are free of amorphous interfaces independent of sintering aids as TiH{sub 2} or MgO/Y{sub 2}O{sub 3}; grain sizes are below 1 {micro}m. With substoichiometric TiC{sub 1{minus}x}, a relative density of 95% and closed porosity are obtained at a lower sintering temperature than with stoichiometric TiC, but subsequent cladless hot isostatic pressing (HIP) is required to achieve 99% density. High densities of 98% accompanied by good mechanical properties become possible by pressureless sintering with the use of TiH{sub 2}. MgO/Y{sub 2}O{sub 3} doping also promotes densification, but results in less transformable zirconia and increases the number and size of amorphous triple junctions. The consequences are a lower fracture toughness and strength.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 131529
- Journal Information:
- Journal of the American Ceramic Society, Vol. 78, Issue 10; Other Information: PBD: Oct 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sintered Al/sub 2/O/sub 3/-SiC-whisker composites
Microstructure Development During Sintering of TiC-Ni3A1 Cermets