Fabrication of porous anisotropic silicon nitride by using partial sinter-forging technique

Porous silicon nitrides with aligned rod-like grains were fabricated by using partial sinter-forging technique, where uni-axial pressure was applied after soaking at elevated temperatures. Rod-like silicon nitride grains were formed during the soaking, and the grains were aligned by the subsequent forging. In this paper, soaking and sintering time was varied to control the formation of anisotropic microstructures. Anisotropy, elastic modulus, strength and fracture energy were measured to discuss the properties in relation to the fabrication conditions.