High strength 7xxx aluminum alloys and methods of making the same

Patent metadata

Field	Value
Publication number	US-2017121802-A1
Application number	US-201615336982-A
Country	US
Kind code	A1
Filing date	Oct 28, 2016
Priority date	Oct 30, 2015
Publication date	May 4, 2017
Grant date	—

Abstract

Described herein are novel 7xxx series aluminum alloys. The alloys exhibit high strength. The alloys can be used in a variety of applications, including automotive, transportation, electronics, aerospace, and industrial applications. Also described herein are methods of making and processing the alloys. Further described herein are methods of producing a metal sheet, which include casting an aluminum alloy as described herein to form an ingot, homogenizing the ingot, hot rolling the ingot to produce a hot band, and cold rolling the hot band to a metal sheet of final gauge.

First claim

What is claimed is:

1 . An aluminum alloy comprising about 4-15 wt. % Zn, 0.1-3.5 wt. % Cu, 1.0-4.0 wt. % Mg, 0.05-0.50 wt. % Fe, 0.05-0.30 wt. % Si, 0.05-0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

2 . The aluminum alloy of claim 1 , comprising about 5.6-9.3 wt. % Zn, 0.2-2.6 wt. % Cu, 1.4-2.8 wt. % Mg, 0.1-0.35 wt. % Fe, 0.05-0.2 wt. % Si, 0.05-0.15 wt. % Zr, 0.01-0.05 wt. % Mn, 0.01-0.05 wt. % Cr, 0.001-0.05 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

3 . The aluminum alloy of claim 1 , comprising about 5.8-9.2 wt. % Zn, 0.3-2.5 wt. % Cu, 1.6-2.6 wt. % Mg, 0.1-0.25 wt. % Fe, 0.07-0.15 wt. % Si, 0.09-0.15 wt. % Zr, 0.02-0.05 wt. % Mn, 0.03-0.05 wt. % Cr, 0.003-0.035 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

4 . The aluminum alloy of claim 1 , comprising about 8.9-9.2 wt. % Zn, 0.2-2.1 wt. % Cu, 2.2-2.4 wt. % Mg, 0.18-0.23 wt. % Fe, 0.09-0.12 wt. % Si, 0.05-0.15 wt. % Zr, 0.04-0.09 wt. % Mn, 0.03-0.09 wt. % Cr, 0.01-0.02 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

5 . The aluminum alloy of claim 1 , comprising about 9 wt. % Zn, 0.3% Cu, 2.3 wt. % Mg, 0.2 wt. % Fe, 0.1 wt. % Si, 0.1 wt. % Zr, 0.05 wt. % Mn, 0.04 wt. % Cr, 0.02 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

6 . The aluminum alloy of claim 1 , comprising about 9.2 wt. % Zn, 1.2 wt. % Cu, 2.3 wt. % Mg, 0.23 wt. % Fe, 0.1 wt. % Si, 0.11 wt. % Zr, 0.04 wt. % Mn, 0.04 wt. % Cr, 0.01 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

7 . The aluminum alloy of claim 1 , comprising about 9.2 wt. % Zn, 2.4% Cu, 1.9 wt. % Mg, 0.19 wt. % Fe, 0.08 wt. % Si, 0.1 wt. % Zr, 0.02 wt. % Mn, 0.03 wt. % Cr, 0.03 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al.

8 . The aluminum alloy of claim 1 , further comprising up to 0.20% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni.

9 . The aluminum alloy of claim 1 , further comprising up to 0.10% of a rare earth element selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

10 . An automotive body part comprising the aluminum alloy of claim 1 .

11 . The automotive body part of claim 10 , wherein the automotive body part is a motor vehicle body part.

12 . The automotive body part of claim 11 , wherein the motor vehicle body part is a bumper, a side beam, a roof beam, a cross beam, a pillar reinforcement, an inner panel, an outer panel, a side panel, an inner hood, an outer hood, or a trunk lid panel.

13 . An electronic device housing comprising the aluminum alloy of claim 1 .

14 . An aerospace body part comprising the aluminum alloy of claim 1 .

15 . The aerospace body part of claim 14 , wherein the aerospace body part is a structural part or a non-structural part.

16 . The aerospace body part of claim 15 , wherein the structural aerospace body part is a wing, a fuselage, an aileron, a rudder, an elevator, a cowling or a support.

17 . The aerospace body part of claim 15 , wherein the non-structural aerospace body part is a seat track, a seat frame, a panel or a hinge.

18 . A product comprising the aluminum alloy of claim 1 , wherein the product is a sheet, a plate, an extrusion, a casting, or a forging.

19 . The product of claim 18 , wherein the product has a maximum pit depth of less than about 40 microns.

20 . The product of claim 18 , wherein the product has an average pit depth of less than about 20 microns.

21 . The product of claim 18 , wherein the product has a yield strength of greater than about 550 MPa.

22 . The product of claim 18 , wherein the product has a yield strength of greater than about 600 MPa.

23 . The product of claim 18 , wherein the aluminum alloy comprises greater than about 0.30 wt % Cu, and the product has a yield strength of greater than about 600 MPa.

24 . The product of claim 23 , wherein the aluminum alloy comprises greater than about 0.80 wt % Cu.

25 . A product comprising the aluminum alloy of claim 5 , wherein the product has a maximum pit depth of less than about 40 microns.

26 . A product comprising the aluminum alloy of claim 5 , wherein the product has an average pit depth of less than about 20 microns.

27 . A product comprising the aluminum alloy of claim 6 , wherein the product has a greater than about 550 MPa.

28 . A product comprising the aluminum alloy of claim 6 , wherein the product has a greater than about 600 MPa.

29 . A method of producing a metal product, comprising:
casting an aluminum alloy to form an ingot or a slab, wherein the aluminum alloy comprises about 4-15 wt. % Zn, 0.1-3.5 wt. % Cu, 1.0-4.0 wt. % Mg, 0.05-0.50 wt. % Fe, 0.05-0.30 wt. % Si, 0.05-0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, and up to 0.15 wt. % of impurities, with the remainder as Al; homogenizing the ingot or the slab; hot rolling the ingot or the slab to produce a hot band; and cold rolling the hot band to a metal product with a final gauge.

30 . The method of claim 29 , wherein the metal product is a sheet.

31 . The method of claim 30 , further comprising subjecting the sheet to a solution heat treatment at a temperature of from about 430° C. to about 600° C.

32 . The method of claim 30 , further comprising subjecting the sheet to a solution heat treatment at a temperature of from about 430° C. to about 500° C.

33 . The method of claim 32 , further comprising cooling the sheet to a temperature of from about 25° C. to about 120° C.

34 . The method of claim 33 , wherein the step of cooling the sheet is performed at a cooling rate from about 200° C. per second to about 600° C. per second.

35 . The method of claim 33 , wherein the step of cooling the sheet is performed at a cooling rate from about 2000° C. per second to about 3000° C. per second.

36 . The method of claim 33 , further comprising subjecting the sheet to an aging process.

37 . The method of claim 36 , wherein the aging process comprises:
heating the sheet to a temperature of from about 100° C. to about 140° C.; maintaining the sheet at a temperature of from about 100° C. to about 140° C. for a period of time; and cooling the sheet to room temperature.

38 . The method of claim 36 , wherein the aging process comprises:
heating the sheet to a temperature of from about 100° C. to about 140° C.; maintaining the sheet at a temperature of from about 100° C. to about 140° C. for a first period of time; heating the sheet to a temperature greater than about 140° C.; maintaining the sheet at a temperature greater than about 140° C. for a second period of time; and cooling the sheet to room temperature.

39 . The method of claim 33 , further comprising subjecting the sheet to paint bake heat treatment.

40 . An aluminum sheet made according to the method of claim 29 .

41 . The sheet of claim 40 , wherein the sheet is in the T6 temper or the T7 temper.

42 . The sheet of c

Assignees

• Novelis Inc

Inventors

• Kamat Rajeev G
• Chakrabarti Dhruba J
• Mohanty Rashmi Ranjan
• Kulkarni Rahul Vilas
• Bendzinski Duane E
• Timm Juergen

Classifications

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title

• C22F1/053 Primary

  of alloys with zinc as the next major constituent · CPC title

• B64C2001/0081

  from metallic materials · CPC title

• B64C3/00

  Wings (ornithopter wings B64C33/02) · CPC title