Preparation of C4 ceramic/metal composites by reactive metal penetration of commercial ceramics

Co-continuous ceramic-metal composites (C4) were prepared by reactive metal penetration of cordierite-based ceramics used as oven refractory. A compositional and physical characterisation of both precursors and composites was carried out to understand how the choice of the starting material affects the reactive metal penetration. Mechanical behaviour was then compared with that of composites obtained from silica glass or fully sintered cordierite ceramics. The results show that the loss in mechanical properties is chiefly due to the presence of a significant residual porosity in the composite, and that the reduction of such porosity allows for an evident improvement of mechanical performance.