Air quenched heat treatment for aluminum alloys

Patent metadata

Field	Value
Publication number	US-2016168676-A1
Application number	US-201414565799-A
Country	US
Kind code	A1
Filing date	Dec 10, 2014
Priority date	Dec 10, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

Methods of processing an air-quenchable aluminum alloy component are provided. The method may include solution heat treating the component, air-quenching the component, and artificially aging the component to a yield strength of at least 200 MPa. The air-quenching may include cooling at a rate of 6° C./s to 25° C./s. The solution heat treatment may include heat treating the component at a temperature of 520° C. to 540° C. and the artificial aging step may include heat treating the component at 235° C. to 255° C. for 0.5 to 2 hours. The disclosed methods may produce a high strength (e.g., over 200 MPa) and high bendability (e.g., r/t ratio up to 0.3) component that does not significantly distort during the quenching process. The disclosed methods may be used to produce structural components having complex shapes, such as multiple, non-coplanar mating surface, while staying within predetermined tolerances.

First claim

What is claimed is:

1 . A method of processing an air-quenchable aluminum alloy component, comprising:
solution heat treating the component; air-quenching the component at a rate of 6° C./s to 25° C./s; and artificially aging the component to a yield strength of at least 200 MPa.

2 . The method of claim 1 , wherein the artificially aging step includes artificially aging the component to have an r/t ratio of at most 0.3.

3 . The method of claim 1 , wherein the solution heat treating step includes heat treating the component at 520° C. to 540° C.

4 . The method of claim 1 , wherein no liquid is used to quench the component.

5 . The method of claim 1 , wherein the air-quenching step includes air-quenching the component at a rate of 8° C./s to 15° C./s.

6 . The method of claim 1 , wherein the air quenching step is performed through at least a temperature range of 475° C. to 290° C.

7 . The method of claim 1 , wherein the artificially aging step includes heat treating the component at 235° C. to 255° C. for 0.5 to 2 hours.

8 . The method of claim 1 , wherein the artificially aging step includes heat treating the component at 240° C. to 250° C. for 0.5 to 1.5 hours.

9 . The method of claim 1 , wherein the air-quenchable aluminum alloy is one of 6061, 6063, 6022, 6008, 6451, 6005, 7003, and 7005.

10 . The method of claim 1 , wherein the air-quenchable aluminum alloy component has multiple, non-coplanar mating surfaces.

11 . The method of claim 1 , wherein the air-quenching step does not distort the component by more than 0.7 mm.

12 . The method of claim 1 further comprising stamping the component in a progressive die prior to the solution heat treating step.

13 . A method of processing an air-quenchable 6xxx series aluminum alloy component, comprising:
solution heat treating the component at a temperature from 520° C. to 540° C.; air-quenching the component through at least a temperature range of 475° C. to 290° C.; and artificially aging the component at a temperature of 235° C. to 255° C. for 0.5 to 2 hours to a yield strength of at least 200 MPa.

14 . The method of claim 13 , wherein the air-quenching step includes air-quenching the component at a rate of 6° C./s to 25° C./s.

15 . The method of claim 13 , wherein the artificially aging step includes artificially aging the component to have an r/t ratio of at most 0.3.

16 . The method of claim 13 , wherein the air-quenchable 6xxx series aluminum alloy component is a structurally reinforcing member having multiple, non-coplanar mating surfaces.

17 . A method of forming a structural vehicle component, comprising:
stamping a sheet of an air-quenchable aluminum alloy in a progressive die to form a component having at least two non-coplanar surfaces; solution heat treating the component; air-quenching the component at a rate of 6° C./s to 25° C./s; and artificially aging the component to a yield strength of at least 200 MPa and an r/t ratio of at most 0.3.

18 . The method of claim 17 , wherein the solution heat treating step includes heat treating the component at 520° C. to 540° C.

19 . The method of claim 17 , wherein the air quenching step is performed through at least a temperature range of 475° C. to 290° C.

20 . The method of claim 17 , wherein the artificially aging step includes heat treating the component at 235° C. to 255° C. for 0.5 to 2 hours.

Assignees

• Ford Global Tech Llc

Inventors

• Luckey Jr S George
• Kozak Stephen Thomas
• Keller Mark
• Dhar Suranjeeta

Classifications

• C22C21/08

  with silicon · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C22F1/002 Primary

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

• C22F1/05

  of alloys of the Al-Si-Mg type, i.e. containing silicon and magnesium in approximately equal proportions · CPC title

• B62D29/00

  Superstructures, {understructures, or sub-units thereof,} characterised by the material thereof {(B62D33/044, B62D33/048 take precedence)} · CPC title