Effect of Oxynitride Grain Boundary Phase on Toughening of Silicon Nitride Ceramics
The Si3N4/YSiO2N composite in which crystalline YSiO2N was formed as grain boundary phase was fabricated by hot-pressing the mixture of SiO2, Si3N4 and Y2O3. The fracture toughness of this composite was significantly improved, compared to the Si3N4 composites containing Y5Si3O12N or Y2Si3O3N4 as a grain boundary phases. To clarify the toughening mechanism, the microstructure and the crack propagation profiles were observed.
T. Ohji, T. Sekino and K. Niihara
T. Kusunose et al., "Effect of Oxynitride Grain Boundary Phase on Toughening of Silicon Nitride Ceramics", Key Engineering Materials, Vols. 317-318, pp. 649-652, 2006