Refractory metal ceramics and methods of making thereof

An article having a surface comprising a composition comprising:

• nanoparticles of a refractory-metal carbide or refractory-metal nitride;
• and
• a carbonaceous matrix;
• wherein the composition is not in the form of a powder;
• and
• wherein the surface of the article comprises an oxide of the refractory metal.

A composition comprising:

• nanoparticles of titanium carbide;
• fibers, carbon fibers, ceramic fibers, or metal fibers;
• and
• a carbonaceous matrix;
• wherein the composition is not in the form of a powder;
• and
• wherein the composition contains less than 20% by volume of voids.

An article having a surface comprising a composition comprising:

• nanoparticles of a refractory-metal carbide or refractory-metal nitride;
• wherein the refractory metal is titanium, zirconium, hafnium, tungsten, tantalum, niobium, molybdenum, or chromium;
• and
• a carbonaceous matrix;
• wherein the composition is not in the form of a powder;
• and
• wherein the article is in the form of a solid, unbroken mass having a minimum size of at least 1 mm in all dimensions.

A composition comprising:

• nanoparticles of a refractory-metal carbide or refractory-metal nitride;
• fibers, carbon fibers, ceramic fibers, or metal fibers;
• and
• a carbonaceous matrix;
• wherein the composition is not in the form of a powder;
• wherein the nanoparticles comprise titanium nitride, zirconium carbide, zirconium nitride, hafnium carbide, hafnium nitride, tungsten carbide, or tantalum carbide;
• or the refractory metal is a group V or VI transition metal, niobium, molybdenum, chromium, or vanadium;
• and
• wherein the composition contains less than 20% by volume of voids.