Welding Process for 2024 and 7075

[planehack]

I am having difficulty finding a welding process for 2024 and 7075 aluminum. I understand that it is not advisable to weld the two types due to intergranular stress corrosion and brittlement issues. However, for a short term interim repair on nonload bearing structure it may prove acceptable. Any help on a published document would be appreciated.

 

[Sparweb]

You can't find a process because there probably isn't one.
You're not supposed to weld 2024 OR 7075. The reasons are well spelled out here:

http://www.alcotec.com/qanda6.htm

The parts in question weren't welded together in the first place were they? Are you sure the parts are 2024/7057? Would a riveted/bolted/bonded connection work just as well?
(BTW, there are specs for welding the grades of AL that are weldable at the bottom of the reference.)

STF

 

[planehack]

I read the information on the referenced website when researching for repair information. The part in question is 2024-T62 0.050” with a crack. The part is nonloadbearing as previously mentioned and has not been previously welded. A riveted/bolted/bonded connection is possible but, an interim weld repair would take less time.
I have cut some test plates from 2024-T3 0.071” and asked the weld shop to join the two test plates together using Alloy 2319 wire. I would have liked to have tried Alloy 4145 as well but it is unavailable. I will post the results of the findings later in the week.

 

[Sparweb]

I look forward to hearing of your results. Keep in mind that the intergranular degradation that the article describes is a process that would take time before its effect is felt. Perhaps the initial test will yield good results, but next year will it be just as good?
Depending on your operating environment, you may have trouble passing this through the regulating authorities, who will quickly identify the welding of 2024 as "bad".
Although the part is not "loadbearing", it MUST be under some stress or it wouldn't be cracking!


STF