Effect of MoSi2 Particles on the Fracture Toughness of AlN-,SiC-,and Si3N4-based Ceramics

Abstract

The effect of 30 vol% MoSi₂ addition on the fracture toughness of AlN-, SiC-, and Si₃N₄-based composites is investigated. To isolate the contribution of MoSi₂ particulate, the toughness of the composite is compared to that of the reference AlN, SiC, and Si₃N₄ matrixes. It turns out that the main toughening mechanisms are residual stress and crack deflection. The residual stress is evaluated through the strain measure in the reinforcing particles by X-ray diffraction, and the crack deflection by analysis of the crack paths. The overall toughening effect is calculated as the sum of these two contributions compared to the experimental values of the toughness of the composites.

Keywords

fracture toughness composites residual stress AlN SiC Si3N4 MoSi2.

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