Fracture Energy of an Aligned Porous Silicon Nitride

The fracture energy of a porous silicon nitride with aligned fibrous grains was investigated, using a chevron-notched-beam technique. A crack was constrained to propagate normal to the grain alignment. The obtained fracture energy was ∼500 J/m2, which was ∼7 times larger than that of a dense silicon nitride with randomly oriented fibrous grains. The large fracture energy was attributable primarily to the sliding resistance associated with interlocking grains.

[1]  T. Ohji,et al.  Strengthening and Toughening of Silicon Nitride by Superplastic Deformation , 2005 .

[2]  S. Kanzaki,et al.  Strain Tolerant Porous Silicon Nitride , 2005 .

[3]  T. Ohji,et al.  High‐Temperature Fracture Energy of Superplastically Forged Silicon Nitride , 2004 .

[4]  T. Ohji,et al.  Superplastic Sinter-Forging of Silicon Nitride with Anisotropic Microstructure Formation , 1999 .

[5]  S. Kanzaki,et al.  Fracture Resistance Behavior of Highly Anisotropic Silicon Nitride , 1995 .

[6]  Masayoshi Ohashi,et al.  Processing Strategy for Producing Highly Anisotropic Silicon Nitride , 1995 .

[7]  Kiyoshi Hirao,et al.  Microstructure Control of Silicon Nitride by Seeding with Rodlike β‐Silicon Nitride Particles , 1994 .

[8]  P. Becher,et al.  Microstructural Contributions to the Fracture Resistance of Silicon Nitride Ceramics , 1994 .

[9]  Y. Akimune,et al.  Effect of Grain Growth of β‐Silicon Nitride on Strength, Weibull Modulus, and Fracture Toughness , 1993 .

[10]  A. Tsuge,et al.  Mechanical Properties of Unidirectionally Oriented SiC‐Whisker‐Reinforced Si3N4 Fabricated by Extrusion and Hot‐Pressing , 1993 .

[11]  M. Mitomo,et al.  Microstructural Development During Gas‐Pressure Sintering of α‐Silicon Nitride , 1992 .

[12]  Takeshi Kawashima,et al.  Grain Size Dependence of the Fracture Toughness of Silicon Nitride Ceramics , 1991 .

[13]  T. Ohji,et al.  High-Temperature Toughness and Tensile Strength of Whisker-Reinforced Silicon Nitride , 1991 .

[14]  A. Kobayashi,et al.  Crack Initiation and Arrest in a SiC Whisker/A12O3 Matrix Composite , 1987 .

[15]  E. Tani,et al.  Gas-pressure sintering of Si3N4 with concurrent addition of Al2O3 and 5 wt% rare, earth oxide: high fracture toughness Si3N4 with fiber-like structure , 1986 .

[16]  Anthony G. Evans,et al.  Crack deflection processes—I. Theory , 1983 .

[17]  A. Evans,et al.  Crack deflection processes—II. Experiment , 1983 .