Method for assembling aluminum alloy parts by welding

Patent metadata

Field	Value
Publication number	US-9555504-B2
Application number	US-201313900485-A
Country	US
Kind code	B2
Filing date	May 22, 2013
Priority date	May 13, 2009
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A welded assembly of aluminum alloy part, in which
(i) at least a first aluminum alloy part is procured in a solution heat treated, quenched, optionally cold worked, and naturally aged at ambient temperature or pre-aged temper, and at least a second aluminum alloy part, (ii) said parts are welded to obtain a welded assembly having a welded zone, (iii) cold working the entire welded zone between 0.3% and 5% is performed, (iv) the welded assembly thus cold worked undergoes post-weld aging to obtain a final metallurgical temper.

First claim

The invention claimed is:

1. A welded assembly obtained by a method comprising:
i) obtaining at least a first aluminum alloy part in a solution heat treated, quenched, optionally cold worked, and naturally aged at ambient temperature and/or pre-aged temper, and at least a second aluminum alloy part,
(ii) welding said parts to obtain a welded assembly having a welded zone,
(iii) cold working the entire welded zone of said welded assembly from 0.3% to 5%, and
(iv) post-weld aging the cold worked welded assembly to obtain a final metallurgical temper wherein said post-weld aging is performed from 120° C. to 200° C. for 10 to 60 hours, and wherein the corrosion resistance according to the Mastmaasis test, performed in accordance with standard ASTM G85 A2 is at least EA, and without the presence of intergranular corrosion throughout the entire welded zone.

2. A welded assembly according to claim 1 , wherein welded members thereof comprise an alloy selected from the group consisting of AA2022, AA2094, AA2098, AA2198, AA2195, AA2196, AA2050, AA2039, AA2124, AA2139, AA2219 and AA2297 and wherein the Vickers microhardness in a weld zone, in a heat affected zone and/or in a thermo-mechanically affected zone thereof is lower, than the Vickers microhardness in a non-welded zone by a factor not more than 20%.

3. The welded assembly according to claim 1 , wherein said cold working is performed by controlled stretching of the welded assembly.

4. The welded assembly according to claim 3 , wherein said first aluminum alloy part is, before welding, in a T 4 temper or in a T 3 temper and with less than 1% cold work.

5. The welded assembly according to claim 3 , wherein said cold working of the welded assembly performed by controlled stretching is from 2% to 4%.

6. The welded assembly according to claim 1 , wherein said cold working is carried out locally by compression.

7. The welded assembly according to claim 6 , wherein said first part aluminum alloy is, before welding, in a T 3 temper, with cold work performed before welding, optionally from 2% to 5%.

8. The welded assembly according to claim 6 , wherein said cold working performed locally is from 0.6% to 2%.

9. The welded assembly according to claim 1 , wherein said final metallurgical temper is T 8 or T 8 X.

10. The welded assembly according to claim 1 , wherein welding is performed by friction stir welding.

11. The welded assembly according to claim 2 , wherein said alloys are an Al—Cu—Li alloy comprising 2 wt % to 5 wt % of copper, 0.8 wt % to 2.5 wt % of lithium, 0.1 wt % to 0.6 wt % of silver, and 0.1 wt % to 1 wt % of magnesium.

12. The welded assembly according to claim 1 , wherein said post-weld aging is performed from 140° C. to 200° C. for 10 to 60 hours.

Assignees

• Constellium France
• Constellium Issoire

Inventors

• Bordesoules-Eberl Isabelle
• Danielou Armelle
• Henon Christine
• Lequeu Philippe

Classifications

• B23K31/00

  Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by any single one of main groups B23K1/00 - B23K28/00 · CPC title

• C21D9/50

  for welded joints · CPC title

• B23K37/00 Primary

  Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass · CPC title

• B23K2103/10

  Aluminium or alloys thereof · CPC title

• C22F1/057

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