Effects of the thermomechanical loading path on the lifetime prediction of self-healing ceramic matrix composites

The objective of this work is to study the infl uence of the loading path on the lifetime of self-healing ceramic matrix composites. The loading can be of different types: mechanical, thermal or chemical. The self-healing process consists of fi lling some cracks with an oxide plug, thus limiting the diffusion of oxygen toward the fi bers. The three phenomena with the greatest infl uence on the lifetime are (a) crack opening, governed by the mechanical part of the loading, (b) volatilization of the oxide plug, and (c) diffusion governed by both the chemical part of the loading and the activation temperature of the chemical reactions. The examples given show the infl uence of each part of the loading path.