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US 8,409,497 B2Granted
Hot and cold rolling high strength L12 aluminum alloys
AssigneeUnited Technologies Corporation
InventorAwadh B. Pandey
Life of this patent
Estimating the term…
Abstract
A method and apparatus for producing high strength aluminum alloys from a powder containing Ll2 intermetallic dispersoids. The powder is degassed, sealed under vacuum in a container, consolidated by vacuum hot pressing, extruded into a rolling preform and rolled into a usable part.
Claims6
A method for forming a high strength aluminum alloy billet containing Ll2 dispersoids, comprising the steps of:
- placing in a container a quantity of an aluminum alloy powder containing an Ll2 dispersoid Ll2 comprising Al3X dispersoids wherein X is at least one first element selected from the group consisting of:
- about 0.1 to about 4.0 weight percent scandium, about 0.1 to about 20.0 weight percent erbium, about 0.1 to about 15.0 weight percent thulium, about 0.1 to about 25.0 weight percent ytterbium, and about 0.1 to about 25.0 weight percent lutetium;
- at least one second element selected from the group consisting of about 0.1 to about 20.0 weight percent gadolinium, about 0.1 to about 20.0 weight percent yttrium, about 0.05 to about 4.0 weight percent zirconium, about 0.05 to about 10.0 weight percent titanium, about 0.05 to about 10.0 weight percent hafnium, and about 0.05 to about 5.0 weight percent niobium;
- and
- the balance substantially aluminum;
- the alloy powder having a mesh size of less than 450 mesh in a container,
- vacuum degassing the powder at a temperature of about 300° F. (149° C.) to about 900° F. (482° C.) for about 0.5 hours to about 8 days;
- sealing the degassed powder in the container under vacuum;
- heating the sealed container at about 300° F. (149° C.) to about 900° F. (482° C.) for about 15 minutes to eight hours;
- vacuum hot pressing the heated container to form a billet;
- removing the container from the formed billet;
- extruding the billet into a rolling preform with a rectangular cross section;
- and
- rolling the preform into a useful shape, wherein the rolling is carried out after soaking the material at temperature from about 250° F. (121° C.) to about −900° F. (482° C.) for about 2 hours to 8 hours and include a plurality of passes wherein the rolling is carried out with an intermediate anneal after each pass at temperatures from about 250° F. (121° C.) to about 900° F. (482° C.) for about 0.25 hour to 1 hour.
11 more elements
A method for forming a high strength aluminum alloy billet containing Ll7 dispersoids, comprising the steps of:
- placing in a container a quantity of an aluminum alloy powder containing an Ll2 dispersoid Ll2 comprising Al3X dispersoids wherein X is at least one first element selected from the group consisting of:
- about 0.1 to about 4.0 weight percent scandium, about 0.1 to about 20.0 weight percent erbium, about 0.1 to about 15.0 weight percent thulium, about 0.1 to about 25.0 weight percent ytterbium, and about 0.1 to about 25.0 weight percent lutetium;
- at least one second element selected from the group consisting of about 0.1 to about 20.0 weight percent gadolinium, about 0.1 to about 20.0 weight percent yttrium, about 0.05 to about 4.0 weight percent zirconium, about 0.05 to about 10.0 weight percent titanium, about 0.05 to about 10.0 weight percent hafnium, and about 0.05 to about 5.0 weight percent niobium;
- and
- the balance substantially aluminum;
- the alloy powder having a mesh size of less than 450 mesh in a container,
- vacuum degassing the powder at a temperature of about 300° F. (149° C.) to about 900° F. (482° C.) for about 0.5 hours to about 8 days;
- sealing the degassed powder in the container under vacuum;
- heating the sealed container at about 300° F. (149° C.) to about 900° F. (482° C.) for about 15 minutes to eight hours;
- vacuum hot pressing the heated container to form a billet;
- removing the container from the formed billet;
- extruding the billet into a rolling preform with a rectangular cross section;
- and
- rolling the preform into a useful shape, wherein the tensile strength of rolled Ll2 alloy billet is about 117 ksi (807 MPa), the yield strength of rolled alloy billet is about 110 ksi (758 MPa), the elongation of rolled Ll2 alloy billet is over 12 percent, the reduction in area of rolled Ll2 alloy billet is over 21 percent, and the rolled Ll2 aluminum alloys have tensile strengths of about 40 ksi (276 MPa) at a temperature of 650° F. (343° C.).
11 more elements
Dependencies are inferred from the claim text.