S042011 Crack Healing Behavior of SiC Whisker Reinforced Si3N4 Composite

Abstract

SiC whisker reinforced Si_3N_4 composite was used for studying crack healing behavior. The semi-elliptical surface cracks with the length of 200μm, 600μm, 3mm were introduced on the specimens using Vickers hardness indenter. The cracked specimens were heat-treated at 1000℃, 1100℃, 1200℃ and 1300℃ for 1 hour in air. Bending strength was measured at room temperature in air by three point bending test system. Bending strength of cracked specimen reduced to about 50% of that of smooth specimen. However, bending strength of some pre-cracked and heat treated specimens recovered completely up to that of smooth specimen.