Method of making dispersion strengthened metal bodies and product

Claim 2

A process for forming an elongated member of substantially uniform cross-section and comprising a metal sheath surrounding a dispersion-strengthened metal core which comprises the steps of: (a) providing a sheath-forming metal container, (b) filling said container with dispersion strengthened metal powder having a particle size less than 20 mesh (Tyler Screen Size) and said dispersion strengthened metal containing from about 0.1% to about 5% by weight of a solute metal as a refractory oxide dispersed therein and having a predetermined tensile strength at full density, (c) the metal of said container having a tensile strength at room temperature in the cold worked condition no more than about 22% to 25% less than said predetermined tensile strength at full density of said core; and (d) reducing the cross-sectional area of the powder filled container by application of compressive force to said container in a plurality of reduction stages each in the range of from about 15% to about 35% of the cross-sectional area until a density of at least about 90% of theoretical density is achieved.

Claim 3

A process as defined in claim 1 in which the compressive force is continuously applied.

Claim 4

A process as defined in claim 1 in which the compressive force is applied by rolling.

Claim 5

A process as defined in claim 1 in which the compressive force is intermittently applied.

Claim 6

A process as defined in claim 1 in which the compressive force is applied by swaging.

Claim 7

A process as defined in claim 1 in which the reduction of the cross-sectional area is continued in a staged manner until full density of the powder is achieved.

Claim 8

A process for forming an elongated member of substantially uniform cross-section and comprising a metal sheath surrounding a densified dispersion strengthened metal core which comprises the steps of: (a) providing a sheath-forming metal container; (b) filling said container with dispersion strengthened metal powder having a particle size less than 20 mesh (Tyler Screen Size) and said dispersion strengthened metal containing from about 0.1% to about 5.0% by weight of a solute metal as a refractory oxide dispersed therein and having a tensile strength at full density of at least about 55,000 psi at room temperature; (c) the metal of said container having a tensile strength at room temperature in the cold worked condition of not more than about 15,000 psi less than the tensile strength of said densified dispersion strengthened metal at maximum density; and (d) reducing the cross-sectional area of the powder filled container by application of compressive force to said container in a plurality of reduction stages each in the range of from about 15% to about 35% of the cross-sectional area until a density of at least about 90% of theoretical density is achieved.

Claim 9

A process for forming an elongated member of substantially uniform cross-section and comprising a metal sheath surrounding a densified dispersion strengthened metal core which comprises the steps of: (a) providing a sheath-forming metal container; (b) filling said container with dispersion strengthened metal powder having a particle size less than 20 mesh (Tyler Screen Size) and said dispersion strengthened metal containing from about 0.1% to about 5.0% by weight of a solute metal as a refractory oxide dispersed therein and having a tensile strength at full density of at least about 55,000 psi at room temperature; (c) the metal of said container having a tensile strength at room temperature in the cold worked condition of not more than about 15,000 psi less than the tensile strength of said densified dispersion strengthened metal at maximum density; and (d) reducing the cross-sectional area of the powder filled container by application of compressive force to said container in a plurality of reduction stages each in the range of from about 15% to about 35% of the cross-sectional area until a density of at least about 90% of theoretical density is achieved.

Claim 10

A process as defined in claim 7 wherein the sheath-forming metal container comprises a plurality of contiguous annuli.

Claim 11

A process as defined in claim 8 wherein at least one of the annuli is a ferrous annulus and another is a copper annulus.

Claim 12

A process as defined in claim 9 wherein the ferruginous annulus is steel.

Claim 13

A process as defined in claim 9 wherein the ferruginous annulus is a nickel-iron alloy.

Claim 14

A process as defined in claim 9 wherein the ferruginous annulus is an inner annulus and the copper annulus is the exterior annulus.

Claim 15

A process as defined in claim 7 in which the compressive force is continuously applied.

Claim 16

A process as defined in claim 7 in which the compressive force is applied by rolling.

Claim 17

A process as defined in claim 7 in which the compressive force is intermittently applied.

Claim 18

A process as defined in claim 7 in which the compressive force is applied by swaging.

Claim 19

A process as defined in claim 7 in which the reduction of the cross-sectional area is continued in a staged manner until full density of the powder is achieved.

Claim 20

The process of claim 1 wherein the size reduction during the later stages after the core has been densified to the extent of at least about 90% of theoretical density is carried out at an elevated temperature of at least 1000° F.

Claim 21

The process of claim 18 wherein the compressive force is applied by swaging.

Claim 22

A process as defined in claim 1 wherein the dispersion strengthened metal is copper.

Claim 23

A process as defined in claim 7 wherein the dispersion strengthened metal is copper.

Claim 24

A process as defined in claim 1 wherein the metal of the container is different from the core matrix metal.

Claim 25

A process as defined in claim 1 wherein the metal of the container is a ferrous metal.

Claim 26

A process as defined in claim 23 wherein the metal of the container is steel.

Claim 27

A process as defined in claim 23 wherein the metal of the container is a stainless steel.

Claim 28

A process as defined in claim 1 wherein the metal of the container is nickel.

Claim 29

A process as defined in claim 1 wherein the metal of the container is copper.

Claim 30

A process as defined in claim 1 wherein the metal of the container is a copper alloy.

Claim 31

A process as defined in claim 28 wherein the metal of the container is a copper/nickel alloy.

Claim 32

A process as defined in claim 1 wherein the dispersion strengthened metal is internally oxidized dispersion strengthened copper.

Claim 33

A process as defined in claim 30 wherein the dispersion strengthened copper is deoxidized.

Claim 34

A process as defined in claim 31 wherein the dispersion strengthened copper is deoxidized by the inclusion in the powder of powdered boron.

Claim 35

A process as defined in claim 1 wherein the refractory oxide is aluminum oxide.

Claim 36

A process as defined in claim 1 wherein the tensile strength of the dispersion strengthened copper at full density is in the range of from about 55,000 psi to about 90,000 psi at room temperature.

Claim 37

A process as defined in claim 1 wherein the size reduction is carried out at least in part at a temperature of from 1100° F. to 1850° F.

Claim 38

A process as defined in claim 1 wherein the tensile strength of the container metal under cold working conditions is at least about 40,000 psi at room temperature.

Claim 39

A process as defined in claim 1 further characterized by the step of shaping a bar in an axial direction.

Claim 40

A process as defined in claim 1 wherein the container includes a removable centrally disposed mandrel whereby a sheathed dispersion strengthened copper tube is formed.

Claim 41

A bar, tube or strip of substantially uniform cross section comprising a metal sheath in tightly adhering relation with a densified dispersion strengthened copper core, said dispersion strengthened copper core containing from about 0.1% to about 4.0% by weight of a metal as a refractory oxide dispersed therein, said core having a tensile strength of at least about 55,000 pounds at room temperature and said sheath having a tensile strength of at least about 40,000 psi at room temperature.

Claim 42

A bar, tube or strip of substantially uniform cross section comprising a metal sheath in tightly adhering relation with a densified dispersion strengthened copper core, said dispersion strengthened copper core containing from about 0.1% to about 4.0% by weight of a metal as a refractory oxide dispersed therein, said core having a tensile strength of at least about 55,000 pounds at room temperature and said sheath having a tensile strength of at least about 40,000 psi at room temperature.

Claim 43

A process as defined in claim 1 wherein the dispersion strengthened copper is deoxidized by the inclusion in the powder of powdered boron, titanium or zirconium, or their hydrides.

Claim 44

A resistance welding electrode having a proximal end and a distal end and formed from a swaged bar and comprising (a) a cylindrical portion characterized by a core of internally oxidized dispersion strengthened copper containing from 0.1 to 4.0% aluminum as refractory aluminum oxide dispersed therein, said core having an ultimate tensile strength developed during swaging to full density of at least about 55,000 psi, said cylindrical portion also having a thin metal sheath surrounding and tightly adhering to said core, said sheath having a cold worked tensile strength at room temperature no more than 15,000 psi below the ultimate tensile strength of said core, said cylindrical body also including a recessed water hole in the proximal end thereof, and (b) a tip portion characterized by converging side surfaces terminating in a circular work-contacting tip, the plan of said circular tip being normal to the longitudinal axis of said electrode.

Claim 45

A resistance welding electrode having a proximal end and a distal end and formed from a swaged bar and comprising (a) a cylindrical portion characterized by a core of internally oxidized dispersion strengthened copper containing from 0.1 to 4.0% aluminum as refractory aluminum oxide dispersed therein, said core having an ultimate tensile strength developed during swaging to full density of at least about 55,000 psi, said cylindrical portion also having a thin metal sheath surrounding and tightly adhering to said core, said sheath having a cold worked tensile strength at room temperature no more than 15,000 psi below the ultimate tensile strength of said core, said cylindrical body also including a recessed water hole in the proximal end thereof, and (b) a tip portion characterized by converging side surfaces terminating in a circular work-contacting tip, the plan of said circular tip being normal to the longitudinal axis of said electrode.

Claim 46

A magnetically responsive wire product having an outer sheath of copper, a contiguous inner ferruginous annulus and a core of fully densified internally oxidized dispersion strengthened copper filling said inner annulus, said core containing from 0.1% to 0.7% aluminum as refractory aluminum oxide dispersed therein.

Claim 47

A magnetically responsive wire product having an outer sheath of copper, a contiguous inner ferruginous annulus and a core of fully densified internally oxidized dispersion strengthened copper filling said inner annulus, said core containing from 0.1% to 0.7% aluminum as refractory aluminum oxide dispersed therein.

Claim 48

A process for forming an elongated member of substantially uniform cross-section and comprising a metal sheath surrounding a dispersion strengthened metal core which comprises the steps of: (a) providing a sheath-forming metal container, (b) filling said container with a metal powder comprising dispersion strengthened metal powder and having a particle size less than 20 mesh (Tyler Screen Size) and said dispersion strengthened metal containing from about 0.1% to about 5% by weight of a solute metal as a refractory oxide dispersed therein and having a predetermined tensile strength at full density, (c) the metal of said container having a tensile strength at room temperature in the cold worked condition no more than about 22% to 25% less than said predetermined tensile strength at full density of said core; and (d) reducing the cross-sectional area of the powder filled container by application of compressive force to said container in a plurality of reduction stages each in the range of from about 15% to about 35% of the cross-sectional area until a density of at least about 90% of theoretical density is achieved.

Claim 49

A process for forming an elongated member of substantially uniform cross-section and comprising a metal sheath surrounding a dispersion strengthened metal core which comprises the steps of: (a) providing a sheath-forming metal container, (b) filling said container with a metal powder comprising dispersion strengthened metal powder and having a particle size less than 20 mesh (Tyler Screen Size) and said dispersion strengthened metal containing from about 0.1% to about 5% by weight of a solute metal as a refractory oxide dispersed therein and having a predetermined tensile strength at full density, (c) the metal of said container having a tensile strength at room temperature in the cold worked condition no more than about 22% to 25% less than said predetermined tensile strength at full density of said core; and (d) reducing the cross-sectional area of the powder filled container by application of compressive force to said container in a plurality of reduction stages each in the range of from about 15% to about 35% of the cross-sectional area until a density of at least about 90% of theoretical density is achieved.