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US 8,894,739 B1Granted
Metal powders with improved flowability
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsCurtis E. Johnson, Kelvin T. Higa, Roger M. Sullivan
Life of this patent
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Abstract
A process to increase the fluidity of metal powders by surface modification with alkylsilane reagents. This invention generally discloses that the most efficient process results from treatment with methyltrichlorosilane in hexane. In particular, the fluidity of aluminum powders having mean diameters smaller than 10 micrometers was considerably improved by the process of embodiments of the invention.
Claims16
A metal powder, comprising:
- a powder having untreated metal particles, wherein said metal particles comprises a reactive metal, wherein said metal particles comprises at least one of aluminum, magnesium, aluminum-magnesium alloy, titanium, and any combination thereof;
- said powder mixed together with a solvent and an alkylchlorosilane or alkylalkoxysilane to form a slurry;
- said metal particles react with the alkylchlorosilane or alkylalkoxysilane to form a reaction mixture having treated metal particles;
- said treated metal particles being separated from the reaction mixture;
- and
- said treated metal particles being subjected to a selected temperature profile to form a treated metal powder having a surface layer of general composition OnRSiX3-2n, where R=alkyl, X=chloro or alkoxy, and n is in the range of 0.5-1.25.
3 more elements
A metal powder, comprising:
- a first powder having metal particles, said first powder exhibiting a first angle of repose, wherein said metal particles comprises a reactive metal, wherein said metal particles comprises at least one of aluminum, magnesium, aluminum-magnesium alloy, titanium, and any combination thereof;
- said first powder wetted with a solvent and alkylchlorosilane or alkylalkoxysilane to form a first mixture;
- said first mixture stirred to contact the metal particles and the alkylchlorosilane or alkylalkoxysilane to form a second mixture having treated metal particles;
- said treated metal particles being removed from the second mixture;
- and
- said treated metal particles being subjected to a selected temperature profile to form a second powder, said second powder exhibiting a second angle of repose less than said first angle of repose, said metal powder having a surface layer of general composition OnRSiX3-2n, where R=alkyl, X=chloro or alkoxy, and n is in the range of 0.5-1.25.
3 more elements
A metal powder, comprising:
- a powder having metal particles, wherein said metal particles comprises a reactive metal, wherein said metal particles comprises at least one of aluminum, magnesium, aluminum-magnesium alloy, titanium, and any combination thereof;
- said powder mixed together with a solvent and at least one of methyltrichlorosilane, ethyltrichlorosilane, tert-butyltrichiorosilane, iso-butyltrichiorosilane, and any combination thereof to form a slurry;
- said metal particles react with said methyltrichlorosilane, ethyltrichlorosilane, tert-butyltrichlorosilane, iso-butyltrichlorosilane and any combination thereof to form a reaction mixture having treated metal particles;
- said treated metal particles being separated from the reaction mixture;
- and
- said treated metal particles being subjected to a selected temperature profile to form a treated metal powder having a surface layer of general composition OnRSiX3-2n, where R=methyl, ethyl, tert-butyl, iso-butyl, and any combination thereof, X=chloro, and n is in the range of 0.5-1.25.
3 more elements
A metal powder, comprising:
- a powder having metal particles, wherein said metal particles comprises a reactive metal, wherein said metal particles comprises at least one of aluminum, magnesium, aluminum-magnesium alloy, titanium, and any combination thereof;
- said powder being exposed to a gas having an alkylchlorosilane vapor or alkylalkoxysilane vapor;
- said metal particles react with the alkylchlorosilane vapor or alkylalkoxysilane vapor to form treated metal particles;
- said treated metal particles being separated from the alkylchlorosilane vapor or alkylalkoxysilane vapor, and
- said treated metal particles being separated from the alkylchlorosilane vapor or alkylalkoxysilane vapor to form a treated metal powder having a surface layer of general composition OnRSiX3-2n, where R=alkyl, X=chloro or alkoxy, and n is in the range of 0.5-1.25.
2 more elements
A metal powder, comprising:
- a powder having metal particles;
- said powder mixed together with a solvent and an alkylchlorosilane to form a first slurry;
- said metal particles react with the alkylchlorosilane to form a reaction mixture having primary treated metal particles;
- said primary treated metal particles being separated from the reaction mixture;
- said primary treated metal particles mixed together with a solvent and hexamethyldisilazane (HMDS) to form a second slurry;
- and
- said primary treated metal particles of said second slurry react with hexamethyldisilazane (HMDS) to form a reaction mixture having secondary treated metal particles.
4 more elements
Dependencies are inferred from the claim text.