Al-Cu-Li alloys with improved cryogenic fracture toughness
First Claim
Patent Images
1. A method for producing an improved aluminum-base alloy comprising the steps of:
- a) providing a solution heat treated and quenched aluminum-base alloy consisting essentially of from 2.0 to 6.5 weight percent Cu, from 0.2 to 2.0 weight percent Li, and the balance aluminum and incidental impurities; and
b) at least one of working and artificially aging said alloy in an amount sufficient to provide strength and fracture toughness to said alloy at cryogenic temperature substantially equal to or greater than the strength and fracture toughness at room temperature, wherein the fracture toughness at room temperature is at least 18.7 ksi√
in and the fracture toughness at -196°
C. is at least 19.2 ksi√
in.
2 Assignments
0 Petitions
Accused Products
Abstract
A method is disclosed for the production of aluminum-copper-lithium alloys that exhibit improved strength and fracture toughness at cryogenic temperatures. Improved cryogenic properties are achieved by controlling the composition of the alloy, along with processing parameters such as the amount of cold-work and artificial aging. The ability to attain substantially equal or greater strength and fracture toughness at cryogenic temperature in comparison to room temperature allows for use of the alloys in cryogenic tanks for space launch vehicles and the like.
64 Citations
39 Claims
-
1. A method for producing an improved aluminum-base alloy comprising the steps of:
-
a) providing a solution heat treated and quenched aluminum-base alloy consisting essentially of from 2.0 to 6.5 weight percent Cu, from 0.2 to 2.0 weight percent Li, and the balance aluminum and incidental impurities; and b) at least one of working and artificially aging said alloy in an amount sufficient to provide strength and fracture toughness to said alloy at cryogenic temperature substantially equal to or greater than the strength and fracture toughness at room temperature, wherein the fracture toughness at room temperature is at least 18.7 ksi√
in and the fracture toughness at -196°
C. is at least 19.2 ksi√
in. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
- 19. A wrought aluminum-base alloy consisting essentially of from 2.8 to 4.8 weight percent Cu, from 0.4 to 1.5 weight percent Li, from 0.2 to 1.0 weigth percent Mg, and the balance aluminum and incidental impurities, wherein said alloy is worked, artificially aged, or worked and artificially aged an amount sufficient to provide strength and fracture toughness to said alloy at cryogenic temperature substantially equal to or greater than the strength and fracture toughness at room temperature, wherein the fracture toughness at room temperature is a least 18.7 ksi√
-
32. A cryogenic material-holding container made from an alloy consisting essentially of from 2.8 to 4.5 weight percent Cu, from 0.4 to 1.5 weight percent Li, from 0.2 to 1.0 weight percent Mg, and the balance aluminum and incidental impurities, wherein said alloy is worked, artificially aged, or worked and artificially aged an amount sufficient to provide strength and fracture toughness to said alloy at cryogenic temperature substantially equal to or greater than the strength and fracture toughness at room temperature, wherein the fracture toughness at room temperature is at least 18.7 ksi√
- in and the fracture toughness at -196°
C. is at least 19.2 ksi√
in. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39)
- in and the fracture toughness at -196°
Specification