Preparation and toughening characterization of high fracture toughness Si3N4 ceramic with rodlike structure
Luo, X. T.
Yuan, R. Z.
- 材料学院－已发表论文 
Silicon nitride ceramic has many advantages in high temperature structural applications such as high strength, creep resistance, and chemical stability. A disadvantage, however, has been its low fracture toughness, typically 4 to 6 MPa m1=2. Whiskerreinforcement is an alternative approach to increase the fracture toughness of Si3N4ceramic, but there exist many problems to be solved such as whisker dispersion, densification, and whisker stability. Re-cently, a new technique called ‘‘self-reinforcement’’ or ‘‘in situtoughening’’ has been applied to improve the fracture toughness of this ceramic, with toughness values reported as high as 8 to 14 MPa m1=2usinggas-pressure-sintering (GPS) or hot-pressing (HP) method in different additive systems .