Interfacial debonding by solid-state reactions of SiC with Ni and Co

Abstract

Composite technologies have received much attention recently because of their advantages in improving specific strength, wear resistance, damping property, and creep and fatigue behavior of various engineering materials for advanced structural applications. Among various reinforcements currently being used in composite materials, ceramic reinforcements such as SiC, Si[sub 3]N[sub 4], Al[sub 2]O[sub 3], ZrO[sub 2], and Y[sub 2]O[sub 3] are the most popular ones. In this paper, the authors report a new form of structural damage induced by matrix/reinforcement chemical reactions in the Ni-SiC and Co-SiC systems. The damage was manifested in the form of interfacial debonding, which was developed underneath the SiC reaction interface. Hypotheses on the basis of liquid-phase infiltration and intergranular diffusion of metal species, as a result of exothermic heat of reaction between the metals and silicon, are proposed to explain the observed phenomenon.