Toughening of glass-ceramics by both transformable and transformed zirconia
Zirconia-containing baria-silica system glass-ceramics were prepared by sintering and crystallizing cold-pressed mixtures of a barium silicate glass powder and 10 vol.% of a pre-heat-treated partially stabilized zirconia powder. At room temperature, all zirconia remained as tetragonal zirconia in glass-ceramics. Upon cooling to sub-zero temperatures tetragonal zirconia in glass-ceramics transformed to monoclinic zirconia, the amount of the transformed zirconia increasing with decreasing temperature. It was found that the room-temperature fracture toughness, K(sub IC), of glass-ceramics, evaluated by the single-edge-precracked-beam method, increased both with increasing grain size of transformable tetragonal zirconia and with increasing amount of transformed monoclinic zirconia. The former is attributed to zirconia transformation toughening, while the latter is largely due to crack deflection toughening.
- Research Organization:
- Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Materials Engineering
- OSTI ID:
- 121855
- Report Number(s):
- AD-A--295050/9/XAB; CNN: Contract DAAL03-91-G-0211
- Country of Publication:
- United States
- Language:
- English
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