Porous refractory hard metal compositions and method of forming same
AssigneeAluminum Company of America
InventorSiba P. Ray
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Abstract
A porous refractory hard metal composition is disclosed which is formed by removing the metal compound from a substantially interwoven matrix composition comprising one or more refractory hard metals and a metal compound. The interwoven matrix composition, in a preferred embodiment, may comprise Al.sub.2 O.sub.3 and TiB.sub.2, ZrB.sub.2, or a mixture of the two refractory hard metals.
Claims20
A porous refractory hard metal composition having an average pore size of at least 0.5 microns and a porosity range of from 0.5 to 0.01 cc/gram, wherein said composition is formed from a substantially interwoven matrix composition consisting essentially of a refractory hard metal and a metal compound.
A porous refractory hard metal composition having a porosity range of from 0.5 to 0.01 cc/gram formed by removal of the metal compound from an interwoven matrix composition consisting essentially of a metal compound and one or more refractory hard metals selected from the class consisting of a nitride, boride, carbide, silicide, or sulfide of titanium, zirconium, hafnium, or chromium and mixtures thereof formed by a displacement reaction which results in uniform dispersion of said metal compound throughout said one or more refractory hard metals resulting in substantially uniform porosity in said composition after removal of said metal compound.
A method of making a porous refractory hard metal composition which comprises removing the metal compound from a substantially interwoven matrix composition consisting essentially of one or more refractory hard metals and a metal compound formed by a displacement reaction, said removing step comprising immersing said interwoven matrix composition in a molten solvent to remove said metal compound.
A method of making a porous refractory hard metal composition which comprises:
- (a) forming a substantially interwoven matrix composition of a refractory hard metal and a metal compound from a mixture comprising first and second reactants capable of reacting to form said refractory hard metal and a third reactant capable of forming said metal compound;
- and
- (b) immersing said interwoven matrix composition in a molten solvent maintained at a temperature of from 200.degree. to 1000.degree. C. capable of dissolving said metal compound out of said interwoven matrix to form said porous refractory hard metal composition.
A method of making a porous refractory hard metal composition having a porosity of from 0.5 to 0.01 cc/gram which comprises:
- (a) forming by a displacement reaction a substantially interwoven matrix composition consisting essentially of:
- (1) a refractory hard metal selected from the class consisting of TiB.sub.2, ZrB.sub.2, and mixtures thereof;
- and
- (2) a metal compound consisting essentially of Al.sub.2 O.sub.3 ;
- from a mixture comprising first and second reactants capable of reacting to form said refractory hard metal and a third reactant capable of forming said metal compound;
- and
- (b) immersing said interwoven matrix composition for a period of from 10 to 50 hours in a molten salt maintained at a temperature of from 200.degree. to 1000.degree. C. and containing cryolite as a solvent capable of dissolving said Al.sub.2 O.sub.3 metal compound within said interwoven matrix while agitating said interwoven matrix composition to dissolve said metal compound out of said interwoven matrix to form said porous refractory hard metal composition;
- whereby dissolving of said metal compound uniformly dispersed throughout said interwoven matrix composition provides a uniform prosity in said resulting porous refractory hard metal composition.
Dependencies are inferred from the claim text.