Method for assembling aluminum alloy parts by welding
View Patent ↗The present disclosure concerns a method for assembling aluminum alloy parts, 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.
1. A method for assembling aluminum alloy parts, 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 from 0.3% to 5%,
(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.
2. The method according to claim 1 , wherein said cold working is performed by controlled stretching of the welded assembly.
3. The method according to claim 2 , wherein said first aluminum alloy part is, before welding, in a T4 temper or in a T3 temper and with less than 1% cold work.
4. The method according to claim 2 , wherein said cold working of the welded assembly performed by controlled stretching is from 2% to 4%.
5. The method according to claim 1 , wherein said cold working is carried out locally by compression.
6. The method according to claim 5 , wherein said first part aluminum alloy is, before welding, in a T3 temper, with cold work performed before welding, optionally from 2% to 5%.
7. The method according to claim 5 , wherein said cold working performed locally is from 0.6% to 2%.
8. A method according to claim 1 , wherein said first aluminum alloy part comprises an aluminum alloy of the 2XXX series.
9. The method according to claim 8 , wherein said alloy of the 2XXX series is an Al—Cu—Li alloy.
10. The method according to claim 8 , wherein said aluminum alloy of the 2XXX series is selected from the group consisting of AA2022, AA2094, AA2098, AA2198, AA2195, AA2196, AA2050, AA2039, AA2139, AA2124, AA2219 and AA2297.
11. A method according to claim 1 , wherein said final metallurgical temper is T8 or T8X.
12. A process according to claim 1 , wherein welding is performed by friction stir welding.
13. The method according to claim 9 , wherein said alloy of the 2XXX series is 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.
14. The method according to claim 1 , wherein said post-weld aging is performed from 140° C. to 200° C. for 10 to 60 hours.
15. The method according to claim 1 , wherein the welded assembly exhibits a corrosion resistance according to the Mastmaasis test, performed in accordance with standard ASTM G85 A2, of at least EA without the presence of intergranular corrosion.