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US 6,759,004 B1Granted
Process for forming microporous metal parts
AssigneeSouthco, Inc.
InventorRatnesh K. Dwivedi
Life of this patent
Estimating the term…
Abstract
A metal injection-molding feedstock is heated and plasticized. Supercritical carbon dioxide is injected into the feedstock to form micropores when the pressure is reduced and a parts mold is filled. The micropores are retained when the green parts are debindered and sintered.
Claims20
A process for forming microporous metal parts, the process comprising
- (a) providing a feedstock comprising metal powder and a binder having a melting point;
- (b) injection molding the feedstock to provide a porous green part, the injection molding comprising
- (1) heating the feedstock to a temperature greater than the melting point of the binder to provide a plasticized feedstock;
- (2) mixing a pore-forming agent with the plasticized feedstock;
- and
- (3) filling a mold with the plasticized feedstock;
- (4) permitting the plasticized feedstock to solidify in the mold;
- (c) debindering the porous green part to substantially remove the binder and provide a debindered porous green part;
- and
- (d) sintering the debindered porous green part.
7 more elements
A process for forming microporous metal structures, the process comprising
- (a) providing a feedstock comprising metal powder and a binder having a melting point;
- (b) extruding the feedstock to provide a porous green structure, the extruding comprising:
- (1) heating the feedstock to a temperature greater than the melting point of the binder to provide a plasticized feedstock;
- (2) mixing a pore-forming agent with the plasticized feedstock;
- and
- (3) passing the plasticized feedstock through a die to impose a shape;
- and
- (4) permitting the plasticized feedstock to solidify to form a porous green structure;
- (c) debindering the porous green structure to substantially remove the binder and provide a debindered porous green structure;
- and
- (d) sintering the debindered porous green structure.
8 more elements
A process for forming microporous ceramic parts, the process comprising
- (a) providing a feedstock comprising powdered ceramic material and a binder having a melting point;
- (b) injection molding the feedstock to provide a porous green part, the injection molding comprising
- (1) heating the feedstock to a temperature greater than the melting point of the binder to provide a plasticized feedstock;
- (2) mixing a pore-forming agent with the plasticized feedstock;
- and
- (3) filling a mold with the plasticized feedstock;
- (4) permitting the plasticized feedstock to solidify in the mold;
- (c) debindering the porous green part to substantially remove the binder and provide a debindered porous green part;
- and
- (d) sintering the debindered porous green part.
7 more elements
A process for forming microporous ceramic structures, the process comprising
- (a) providing a feedstock comprising powdered ceramic material and a binder having a melting point;
- (b) extruding the feedstock to provide a porous green structure, the extruding comprising:
- (1) heating the feedstock to a temperature greater than the melting point of the binder to provide a plasticized feedstock;
- (2) mixing a pore-forming agent with the plasticized feedstock;
- and
- (3) passing the plasticized feedstock through a die to impose a shape;
- and
- (4) permitting the plasticized feedstock to solidify to form a porous green structure;
- (c) debindering the porous green structure to substantially remove the binder and provide a debindered porous green structure;
- and
- (d) sintering the debindered porous green structure.
8 more elements
Dependencies are inferred from the claim text.