Production of Al alloys with improved properties

Claim 2

A process for improving the fracture toughness in the non-aged condition with substantially no reduction in tensile properties, of a product composed of an alloy containing, by weight, about 0.5 to about 4% lithium, 0 up to about 7% magnesium, 0 up to about 6% copper, 0 up to about 2% zirconium, 0 up to about 5% cerium, 0 up to about 6% zinc, 0 up to about 2% silicon, 0 up to about 5% carbon, 0 up to about 2% oxygen, and the balance essentially aluminum, and wherein the alloy product further contains 0 up to about 10% by volume of a dispersoid, which comprises: shaping the alloy at a homologous temperature of said alloy below about 0.75, heat treating the shaped product above the temperature of the shaping treatment, provided said heat treating temperature is a homologous temperature in the range of about 0.65 up to about 0.85, and cooling the resultant heat treated shaped product.

Claim 3

A process according to claim 1, wherein shaping is accomplished by rolling.

Claim 4

A process according to claim 1, wherein cooling is accomplished outside the furnace and by a method selected from the group air cooling and liquid quenching.

Claim 5

A process according to claim 1, wherein the product is formed by a powder metallurgy route.

Claim 6

A process according to claim 1, wherein the product is formed by an ingot metallurgy route.

Claim 7

A process according to claim 1, wherein the shaping is accomplished by forging.

Claim 8

A process according to claim 4, wherein the shaping is accomplished by forging.

Claim 9

A process according to claim 3, wherein the cooling is accomplished by air cooling.

Claim 10

A process according to claim 1, wherein subsequent to cooling the product is aged.

Claim 11

A process for improving the fracture toughness in the non-aged condition, without sacrificing substantially tensile properties, of a product made from an aluminum-lithium alloy powder comprising, by weight, 0 to about 4% lithium, 0 to about 7% magnesium, 0 to about 2% oxygen, 0 to about 5% carbon and the balance essentially aluminum, which comprises: degassing and compacting the powder at temperature in the range of about 480° C. up to the incipient melting temperature of the alloy, consolidating the compaction and then shaping the consolidated material by a thermomechanical treatment at a homologous temperature of said alloy below 0.75, subjecting the resultant shaped product to a homologous temperature above the temperature above the temperature of the thermomechanical treatment, provided said heat treating temperature is a homologous temperature in the range of 0.65 to 0.85, and cooling the resultant heat treated shaped product.

Claim 12

A process for improving the fracture toughness in the non-aged condition, without sacrificing substantially tensile properties, of a product made from an aluminum-lithium alloy powder comprising, by weight, 0 to about 4% lithium, 0 to about 7% magnesium, 0 to about 2% oxygen, 0 to about 5% carbon and the balance essentially aluminum, which comprises: degassing and compacting the powder at temperature in the range of about 480° C. up to the incipient melting temperature of the alloy, consolidating the compaction and then shaping the consolidated material by a thermomechanical treatment at a homologous temperature of said alloy below 0.75, subjecting the resultant shaped product to a homologous temperature above the temperature above the temperature of the thermomechanical treatment, provided said heat treating temperature is a homologous temperature in the range of 0.65 to 0.85, and cooling the resultant heat treated shaped product.

Claim 13

A process according to claim 10, wherein shaping is effected by steps comprising forging.

Claim 14

A process according to claim 11, wherein the alloy contains up to 23/4% lithium.

Claim 15

A process according to claim 11, wherein the alloy consists essentially of about 1 to 23/4% lithium, about 2 to about 4.5% magnesium, a small but effective amount for increased strength up to about 2% carbon, a small but effective amount for increased strength and temperature stability up to about 2% oxygen.

Claim 16

An aluminum-base alloy product produced by the method of claim 1.

Claim 17

A dispersion strengthened aluminum-lithium-magnesium alloy produced by the method of claim 11.

Claim 18

A dispersion strengthened aluminum-lithium-magnesium alloy consisting essentially of about 1 to about 3% lithium, about 1 to about 5% magnesium, a small but effective amount for increased strength up to about 2% carbon, a small but effective amount for increased strength up to about 2% oxygen, said alloy having in the forged heat-treated, non-aged condition a Y.S. (0.2% offset) of at least 414 MPa (60 Ksi), and a fracture toughness of at least about 22 MPa m 1/2 (20 Ksi in 1/2 ).

Claim 19

A dispersion strengthened aluminum-lithium-magnesium alloy consisting essentially of about 1 to about 3% lithium, about 1 to about 5% magnesium, a small but effective amount for increased strength up to about 2% carbon, a small but effective amount for increased strength up to about 2% oxygen, said alloy having in the forged heat-treated, non-aged condition a Y.S. (0.2% offset) of at least 414 MPa (60 Ksi), and a fracture toughness of at least about 22 MPa m 1/2 (20 Ksi in 1/2 ).

Claim 20

A dispersion strengthened alloy according to claim 16, wherein the alloy is comprised of about 1 up to about 23/4% lithium and about 2 to about 4% magnesium.

Claim 21

A dispersion strengthened alloy according to claim 16, wherein the alloy is comprised of about 1.5% lithium and about 4% magnesium.

Claim 22

A process according to claim 5, wherein the shaping is accomplished by forging.

Claim 23

A shaped article composed of a dispersion strengthened aluminum-lithium-magnesium alloy consisting essentially of about 1 to about 3% lithium, about 1 to about 5% magnesium, a small but effective amount for increased strength up to about 2% carbon, a small but effective amount for increased strength up to about 2% oxygen, said alloy having in the forged, heat-treated, non-aged condition a Y.S. (0.2% offset) of at least 414 MPa (60 Ksi), and a fracture toughness of at least about 22 MPa m 1/2 (20 Ksi in 1/2 ).

Claim 24

A shaped article composed of a dispersion strengthened aluminum-lithium-magnesium alloy consisting essentially of about 1 to about 3% lithium, about 1 to about 5% magnesium, a small but effective amount for increased strength up to about 2% carbon, a small but effective amount for increased strength up to about 2% oxygen, said alloy having in the forged, heat-treated, non-aged condition a Y.S. (0.2% offset) of at least 414 MPa (60 Ksi), and a fracture toughness of at least about 22 MPa m 1/2 (20 Ksi in 1/2 ).

Claim 25

A process according to claim 1 wherein the shaping treatment is accomplished by extruding.

Claim 26

A process according to claim 1 wherein the shaping treatment is accomplished by hammering.

Claim 27

A process according to claim 1 wherein the shaping treatment is accomplished by swaging.

Claim 28

A process according to claim 1 wherein the shaping treatment is accomplished by coining.

Claim 29

A process according to claim 1 wherein the shaping treatment is accomplished by upsetting.