Process for forming metal-ceramic composites

DETAILED DESCRIPTION It is an object of the present invention to provide an inexpensive method for forming composite materials, consisting of finely dispersed particulate ceramic or intermetallic materials in metal, metallic alloy, or intermetallic matrices.
It is a further object of this invention to provide a method for dispersion hardening of metals and alloys.
It is a particular object of this invention to provide a method for the formation of submicron titanium diboride particulates in an aluminum matrix, without the necessity for utilizing expensive submicron starting materials.
The present invention relates to a process for the in-situ precipitation of up to about 95 percent by weight of a ceramic material in a metallic matrix, wherein the ceramic comprises a boride, carbide, oxide, nitride, silicide, aluminide, selenide, sulfide, or germanide, of a metal other than the matrix metal.
It has been found that by mixing the constituents or elements of the desired ceramic material with a solvent matrix metal, and heating to a temperature at which substantial diffusion and/or solvation of the reactive elements in the matrix can occur, typically, close to the incipient melting point of the solvent matrix metal, a solvent assisted reaction, which is generally exothermic, can be initiated.
This solvent assisted reaction results in the extremely rapid formation and dispersion of finely divided particles of the ceramic material in the metal matrix.
While this invention may be associated with pure metal systems, it is also applicable to alloys wherein at least two alloying elements react to form a ceramic precipitate in a matrix of the metal or an alloy thereof.