A low CTE
metal-
ceramic composite material featuring
carbon fibers reinforcing a matrix featuring
silicon metal or
silicon alloy. The fibers have a low coefficient of
thermal expansion (CTE) in the axial direction, and preferably negative. The principles of making Si / SiC composites can be adapted to produce the instant Si matrix composites. The CTE of the composite body depends not only upon the relative CTE's of the fibers and matrix, and their relative amounts (e.g., loadings), but also upon the relative elastic moduli of the fibers and matrix. Thus, Si / SiC matrices produced by a reaction-
bonding process inherently possess low CTE, but the instant inventors prefer to make such composites having relatively large fractions of unreacted
silicon, thereby driving composite CTE lower still. Here, the
carbon fibers are protected from reaction with the silicon infiltrant with one or more materials disposed between the fibers and the infiltrant. Providing at least a degree of
toughness or
impact resistance can also be realized in these composites. Laminates produce Isotropic or quasi-isotropic properties in the composite body can be realized by, for example, providing the fibers in the form of cross-plied laminates featuring the fibers in parallel or woven arrays.