Mechanisms of energy absorption in the creep fracture of woven ceramic composites

A micromechanical model is developed which accounts for the energy absorbed in the creep deformation and fracture of a 2.5D SiC/C/SiC composite, representative of the new generation of non-oxide CMCs. The model quantifies the influence of the geometrical, mechanical and material parameters and, in particular, is very sensitive to the interfacial sliding stress. The effect of the sliding stress on the contribution of the different energy absorbing mechanisms in the creep fracture of CMCs is described. It is concluded that, for all testing conditions, most of the energy absorbed in the creep fracture is controlled by fibre–matrix debonding and fibre pull-out.