Method of making dimensionally reproducible compacts

Claim 1

A method of forming a pressed, dense article comprising the steps: (1) providing a compactable particulate combination; (2) uniaxially pressing the particulate combination to a theoretical density of from 60% to 95%, to provide a consolidated article having the length and width desired in the final article but with the height larger than desired in the final article; (3) placing at least one article in an open pan having a bottom surface and containing side surfaces that are not significantly pressure deformable, which side surfaces are parallel to the central axis of the pan, where the article is placed such that its height direction is parallel to the central axis of the pan, and where the article contacts a separation material which aids subsequent separation of the article and the pan; (4) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (5) hot pressing the article through the sealed pan in the height direction of the article, where the pan side surfaces prevent significant lateral deformation of the article, at a pressure over 352.5 kg/cm 2 (5,000 psi), to provide simultaneous hot-pressing and densification of the entire article; (6) cooling and releasing pressure on the article; and (7) separating the densified article from the pan.

Claim 2

A method of forming a pressed, dense article comprising the steps: (1) providing a compactable particulate combination; (2) uniaxially pressing the particulate combination to a theoretical density of from 60% to 95%, to provide a consolidated article having the length and width desired in the final article but with the height larger than desired in the final article; (3) placing at least one article in an open pan having a bottom surface and containing side surfaces that are not significantly pressure deformable, which side surfaces are parallel to the central axis of the pan, where the article is placed such that its height direction is parallel to the central axis of the pan, and where the article contacts a separation material which aids subsequent separation of the article and the pan; (4) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (5) hot pressing the article through the sealed pan in the height direction of the article, where the pan side surfaces prevent significant lateral deformation of the article, at a pressure over 352.5 kg/cm 2 (5,000 psi), to provide simultaneous hot-pressing and densification of the entire article; (6) cooling and releasing pressure on the article; and (7) separating the densified article from the pan.

Claim 5

A method of forming a pressed, dense, dimensionally predictable and reproducible metal compact, comprising the steps: (1) mixing: (a) powders selected from Class 1 metals consisting of Ag, Cu, Al, and mixtures thereof, with (b) powders selected from the class consisting of CdO, SnO, SnO 2 , C, Co, Ni, Fe, Cr, Cr 3 C 2 , Cr 7 C 3 , W, WC, W 2 C, WB, Mo, Mo 2 C, MoB, Mo 2 B, TiC, TiN, TiB 2 , Si, SiC, Si 3 N 4 , and mixtures thereof; (2) uniaxially pressing the powders to a theoretical density of from 60% to 95%, to provide a compact having the length and width desired in the final compact but with the height larger than desired in the final compact; (3) placing at least one compact in an open pan having a bottom surface, and containing side surfaces that are not significantly pressure deformable, which side surfaces are parallel to the central axis of the pan, where the compact is placed such that there are no significant gaps between the compact and the side surfaces, and the compact's height direction is parallel to the central axis of the open pan, and where the compact contacts a separation material which aids subsequent separation of the compact and the pan; (4) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (5) hot pressing the compact through the sealed pan in the height direction of the compact, where the pan side surfaces prevent significant lateral deformation of the compact, at a pressure between 352.5 kg/cm 2 and 3,172 kg/cm 2 , to provide simultaneous hot-pressing and densification of the entire compact to over 97% of theoretical density; (6) cooling and releasing pressure on the compact; and (7) separating the compact from the pan.

Claim 6

A method of forming a pressed, dense, dimensionally predictable and reproducible metal compact, comprising the steps: (1) mixing: (a) powders selected from Class 1 metals consisting of Ag, Cu, Al, and mixtures thereof, with (b) powders selected from the class consisting of CdO, SnO, SnO 2 , C, Co, Ni, Fe, Cr, Cr 3 C 2 , Cr 7 C 3 , W, WC, W 2 C, WB, Mo, Mo 2 C, MoB, Mo 2 B, TiC, TiN, TiB 2 , Si, SiC, Si 3 N 4 , and mixtures thereof; (2) uniaxially pressing the powders to a theoretical density of from 60% to 95%, to provide a compact having the length and width desired in the final compact but with the height larger than desired in the final compact; (3) placing at least one compact in an open pan having a bottom surface, and containing side surfaces that are not significantly pressure deformable, which side surfaces are parallel to the central axis of the pan, where the compact is placed such that there are no significant gaps between the compact and the side surfaces, and the compact's height direction is parallel to the central axis of the open pan, and where the compact contacts a separation material which aids subsequent separation of the compact and the pan; (4) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (5) hot pressing the compact through the sealed pan in the height direction of the compact, where the pan side surfaces prevent significant lateral deformation of the compact, at a pressure between 352.5 kg/cm 2 and 3,172 kg/cm 2 , to provide simultaneous hot-pressing and densification of the entire compact to over 97% of theoretical density; (6) cooling and releasing pressure on the compact; and (7) separating the compact from the pan.

Claim 23

A method of forming pressed, dense, dimensionally predictable and reproducible compacts, comprising the steps: (1) mixing: (a) powders selected from Class 1 metals consisting of Ag, Cu, Al, and mixtures thereof, with (b) powders selected from the class consisting of CdO, SnO, SnO 2 C, Co, Ni, Fe, Cr, Cr 3 C 2 , Cr 7 C 3 , W, WC, W 2 C, WB, Mo, Mo 2 C, Mob, Mo 2 B, TiC, TiN, TiB 2 , Si, SiC, Si 3 N 4 , and mixtures thereof; (2) heating the powders in a reducing atmosphere, at a temperature effective to provide an oxide clean surface on the powders, except CdO, SnO, or SnO 2 , if present, and more homogeneous distribution of Class 1 metals; (3) granulating the powders to where the powder particles have diameters up to approximately 1,500 micrometers; (4) uniaxially pressing the powders to a theoretical density of from 60% to 95%, to provide compacts all having the length and width desired in the final compacts but all having a height larger than desired in the final compacts; (5) placing a plurality of compacts in an open, shallow pan having a bottom surface, and containing sides and a separate, closely fitting frame, having an open top and bottom, next to the sides of the pan, which frame is not significantly pressure deformable, and which sides are parallel to the central axis of the open pan, where the compacts are placed such that there are no significant gaps between the compacts and the side surfaces, and all the compacts' height directions are parallel to the central axis of the open pan, and where the compacts contact a separation material which aids subsequent separation of the compacts and the pan; (6) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (7) hot pressing the compacts through the sealed pan in the height direction of the compacts, where the frame prevents significant lateral deformation of the compacts, at a pressure between 352.5 kg/cm 2 and 3,172 kg/cm 2 and at a temperature from 0.5° C. to 100° C. below the melting point or decomposition point of the lowest melting component of the compacts, to provide simultaneous hot-pressing and densification of the entire surface of the compacts to over 97% of theoretical density; (8) gradually cooling and releasing pressure on the compacts; and (9) separating the compacts from the pan.

Claim 24

A method of forming pressed, dense, dimensionally predictable and reproducible compacts, comprising the steps: (1) mixing: (a) powders selected from Class 1 metals consisting of Ag, Cu, Al, and mixtures thereof, with (b) powders selected from the class consisting of CdO, SnO, SnO 2 C, Co, Ni, Fe, Cr, Cr 3 C 2 , Cr 7 C 3 , W, WC, W 2 C, WB, Mo, Mo 2 C, Mob, Mo 2 B, TiC, TiN, TiB 2 , Si, SiC, Si 3 N 4 , and mixtures thereof; (2) heating the powders in a reducing atmosphere, at a temperature effective to provide an oxide clean surface on the powders, except CdO, SnO, or SnO 2 , if present, and more homogeneous distribution of Class 1 metals; (3) granulating the powders to where the powder particles have diameters up to approximately 1,500 micrometers; (4) uniaxially pressing the powders to a theoretical density of from 60% to 95%, to provide compacts all having the length and width desired in the final compacts but all having a height larger than desired in the final compacts; (5) placing a plurality of compacts in an open, shallow pan having a bottom surface, and containing sides and a separate, closely fitting frame, having an open top and bottom, next to the sides of the pan, which frame is not significantly pressure deformable, and which sides are parallel to the central axis of the open pan, where the compacts are placed such that there are no significant gaps between the compacts and the side surfaces, and all the compacts' height directions are parallel to the central axis of the open pan, and where the compacts contact a separation material which aids subsequent separation of the compacts and the pan; (6) evacuating air from the pan and sealing the open top portion of the pan, where at least one of the top and bottom surfaces of the pan is pressure deformable; (7) hot pressing the compacts through the sealed pan in the height direction of the compacts, where the frame prevents significant lateral deformation of the compacts, at a pressure between 352.5 kg/cm 2 and 3,172 kg/cm 2 and at a temperature from 0.5° C. to 100° C. below the melting point or decomposition point of the lowest melting component of the compacts, to provide simultaneous hot-pressing and densification of the entire surface of the compacts to over 97% of theoretical density; (8) gradually cooling and releasing pressure on the compacts; and (9) separating the compacts from the pan.