Production of ceramic and ceramic-metal composite articles with surface coatings

A self-supporting ceramic composite armor material comprising:

• (1) a ceramic matrix which consists essentially of
• (i) interconnected crystallites of an essentially single phase polycrystalline oxidation reaction product of an aluminum parent metal with a vapor-phase oxidant, and about 1 to 40 percent by volume, of
• (ii) a metallic constituent consisting of one or more non-oxidized constituents of said parent metal, and optionally,
• (iii) voids;
• (2) one or more inert fillers embedded in said matrix, and wherein said metallic constituent is dispersed in said matrix in the form of planar metallic channels which are interconnected and, optionally, also in the form of substantially non-interconnected metallic inclusions, and wherein said oxidation reaction product is characterized by crystal lattice misalignments at crystallite grain boundaries which are less than the lattice misalignments between neighboring crystallites between which planar metallic channels or planar voids are disposed;
• and
• (3) a first coating comprising a conversion coating disposed on at least a portion of the exterior surface of said ceramic composite armor material and a second coating disposed on top of said first coating, wherein at least one of said first coating and said second coating improve the ballistic performance of said ceramic composite armor material relative to an essentially identical ceramic composite armor material without said first coating and said second coating disposed thereon.

A self-supporting ceramic composite body which consists essentially of:

• (1) a ceramic matrix which consists essentially of
• (i) interconnected crystallites of an essentially single phase polycrystalline oxidation reaction product of a parent metal with a vapor-phase oxidant, and
• (ii) about 1 to 40 percent by volume of a primarily interconnected metallic constituent consisting of one or more non-oxidized constituents of said parent metal, and optionally,
• (iii) voids;
• (2) one or more inert fillers embedded in said matrix, and wherein said metal constituent is dispersed in said matrix in the form of planar metal channels which are interconnected and, optionally, also in the form of substantially non-interconnected metal inclusions, and wherein said oxidation reaction product is characterized by crystal lattice misalignments at crystallite grain boundaries which are less than the lattice misalignments between neighboring crystallites between which planar metal channels or planar voids are disposed;
• and
• (3) a first coating comprising a conversion coating disposed on at least a portion of the exterior surface of said ceramic composite body and a second coating disposed on top of said first coating.