Abstract: A ceramic composite is disclosed which may be used as lightweight armor or for other impact or wear resisting purposes. The ceramic composite may comprise distinct phases of AlN and SiC; may be a solid solution of SiC; or may contain AlN or SiC, or both AlN and SiC as residual phase(s) in a solid solution matrix of SiC and AlN.

Abstract: A spall backing material contiguously attached to an armor plate at least suppresses the formation of lethal armor spall from being propelled from the inner surface of the armor plate when the outer surface of the armor is impacted by a weapon with sufficient impact to release high velocity spall from unprotected armor. When the impedance of the spall suppression armor is equal to or greater than the impedance of the armor plate, the formation of lethal spall in the armor will be prevented. When the spall backing material is reduced in thickness to minimize weight and has an impedance lower than that of the armor plate, or a more powerful weapon is used, armor spallation will occur but will be suppressed by the spall backing material to minimize lethality.

Abstract: A porous refractory object, more particularly a porous silicon carbide igniter is shown, the interconnecting pores and passageways of its body being filled with sub-micron sized silicon carbide particles deposited therein from a slurry coated on the surface of the object, which particles are subsequently oxidized at least on the surface and within the passages or pores in the subjacent surface portion of the body, to provide a protective coating of silica within the pores and on the surfaces of the object to preclude oxidation of the internal phases of the body of the object in oxidizing atmospheres.