Abstract
High-temperature creep resistance in Si3N4 is highly improved by crystallization of intergranular glassy phase. The Si3N4-4.7mol%Yb2O3-1.1mol%SiO2 fabricated by hot-pressing at 1750°C for 4 h under a pressure of 20 MPa in nitrogen gas flow exhibits excellent creep resistance at 1370°C in comparison with other Si3N4 ceramics doped with rare-earth oxides. The steady-state creep rate is about 1 × 10-8 s-1 at 1370°C under a stress of 200 MPa in the Yb2O3-fluxed Si3N4. The grain boundary phase consists of about 80% of crystalline Yb4Si2O7N2 phase and the rest of amorphous phase. The excellent creep resistance of this material is caused by the grain boundary Yb4Si2O7N2 phase, which has a high melting temperature of 1870°C and is easily crystallized during sintering.
| Original language | English |
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| Pages | 653-662 |
| Number of pages | 10 |
| Publication status | Published - 1997 Dec 1 |
| Event | Proceedings of the 1997 7th International Conference on Creep and Fracture of Engineering Materials and Structures - Irvine, CA, USA Duration: 1997 Aug 10 → 1997 Aug 15 |
Other
| Other | Proceedings of the 1997 7th International Conference on Creep and Fracture of Engineering Materials and Structures |
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| City | Irvine, CA, USA |
| Period | 97/8/10 → 97/8/15 |
ASJC Scopus subject areas
- Engineering(all)