Process for forming fine ceramic powders

A method for the production of fine second phase powders, the method comprising steps of:

• (a) preparing a mixture comprising powders of reactive second phase-forming reactants and a substantially nonreactive solvent metal in which the second phase-forming reactants are more soluble than the second phase;
• (b) adding the mixture to a molten matrix metal, metal alloy or intermetallic at a temperature at which sufficient diffusion of the second phase-forming reactants into the solvent metal occurs to initiate an exothermic reaction;
• (c) permitting the exothermic reaction to further heat the mixture, consuming the second phase-forming reactants to form a composite comprising a distribution of second phase particles in a final metal matrix;
• (d) substantially separating the second phase particles from the final metal matrix;
• and
• (e) recovering a powder comprising the second phase particles.

A method for the production of the fine second phase powders, the method comprising steps of:

• (a) preparing a mixture comprising powders of reactive second phase-forming reactants and a substantially nonreactive solvent metal in which the second phase-forming reactants are more soluble than the second phase;
• (b) heating the mixture to a reaction initiation temperature approximating the melting point of the solvent metal to initiate an exothermic reaction;
• (c) permitting the exothermic reaction to further heat the mixture, consuming the second phase-forming reactants to form a first composite comprising a distribution of second phase particles in a solvent metal matrix;
• (d) introducing the first composite into a host metal to thereby form a second composite comprising particles of the second phase in a final metal matrix comprising an alloy of the solvent metal with the host metal;
• (e) substantially separating the second phase particles from the final metal matrix;
• and
• (f) recovering a powder comprising the second phase particles.

A method for the production of fine second phase powders, the method comprising steps of:

• (a) preparing a mixture comprising powders of reactive second phase-forming reactants and a first intermetallic precursor in which the second phase-forming reactants are more soluble than the second phase;
• (b) heating the mixture to a reaction initiation temperature approximating the melting point of the first intermetallic precursor to initiate an exothermic reaction;
• (c) permitting the exothermic reaction to further heat the mixture, consuming the second phase-forming reactants to form a first composite comprising a distribution of second phase particles in a first intermetallic precursor matrix;
• (d) introducing the first composite into a second intermetallic precursor to thereby form a second composite comprising particles of the second phase in an intermetallic containing matrix;
• (e) substantially separating the second phase particles from the intermetallic containing matrix;
• and
• (f) recovering a powder comprising the second phase particles.