Mechanical Properties of Unidirectionally Oriented SiC‐Whisker‐Reinforced Si ₃ N ₄ Fabricated by Extrusion and Hot‐Pressing

Abstract

SiC‐whisker‐reinforced Si 3 N 4 was fabricated by extrusion and hot‐pressing. A unidirectional alignment of the whiskers was achieved through sheet forming by extrusion. The degree of whisker orientation changed with the thickness of the green sheets. Unidirectionally oriented whiskers increased fracture strength and toughness compared to samples with more randomly oriented whiskers. Anisotropy of fracture strength was observed. Bridging by whiskers impeded crack propagation when the whisker orientation was perpendicular to the crack plane.