Generally, the mechanical behaviour of the fibre bundles in alloxide CMCs differs fundamentally from that found in conventional, polymer-based unidirectional composites. In the latter, the ductile matrix phase exhibits high strain-to-failure but low strength. The embedded fibres primarily stiffen and reinforce the polymer matrix. The axial tensile strength of the fibre bundles depends on the statistical strength properties of the fibres, the shear properties of the matrix phase and the fibre-matrix bond strength [3–7].