Indirect measurement of the viscosity of the intergranular glass phase in yttria-sintered silicon nitride
Abstract
Dense, sintered Si3N4 possesses a residual intergranular glass phase which softens at high temperatures, resulting in degradation of the ceramic's mechanical properties at high temperatures. An important parameter in the determination of the high temperature mechanical properties of sintered Si3N4 is the temperature-viscosity relationship of the intergranular glass. A method for indirectly measuring the intergranular glass viscosity at a given temperature using physical modelling of a two phase glass crystal microstructure and beam bending viscometry measurements of Si3N4 is described. Intergranular glass viscosities obtained by this method are presented for a yttria sintered Si3N4.
- Publication:
-
In its Crystallization of the Glassy Grain Boundary Phase in Silicon Nitride Ceramics 16 p (SEE N91-31961 23-76
- Pub Date:
- August 1991
- Bibcode:
- 1991cggb.nasaR....D
- Keywords:
-
- Ceramics;
- Glass;
- Microstructure;
- Silicon Nitrides;
- Sintering;
- Viscosity;
- Yttrium Oxides;
- Bending;
- Crystallinity;
- Degradation;
- High Temperature Research;
- Refractory Materials;
- Viscometry;
- Solid-State Physics