Straightening 2024-T42 Aluminum

[jallenc]

Why is it necessary to complete straightening operations prior to completion of natural aging of 2024-T42 material? I believe the controlling specification says to place parts into a freezer to slow down the aging process if you cannot straighten right away.
Does this mean that if natural aging takes 96 hours, I can straighten any time within the 96 hours without placing in a freezer?

 

[jedishrfu]

While I don't know the answer to your question, you might find it here in this Aluminum Association publication:

http://www.aluminum.org/sites/default/files/Rolling_Aluminum_From_The_Mine_Through_The_Mill.pdf

and here's another reference although somewhat technical:

http://www.jnhaide.com/pdf/AMS2770H.pdf

In the meantime, perhaps some other PF member will comment on this thread and be able to more definitively answer your question.

 

[Nidum]

It is just a situation of having the metal in the annealed condition for any straightening or other forming operations . As the age hardening process develops the metal gets harder to work and more prone to spring back and cracking .

Ideally the metal should be worked in the freshly annealed condition . Some small delay may be acceptable but if 96 hours is the time for full hardening to develop then acceptable delay would not usually be more than 1 or 2 hours .

Freezing to inhibit age hardening is a non preferred process in the manufacture of safety critical components .

 

[the professor]

at MCMURDO STATION - the aluminum steps to the buildings sagged and bowed in the worst way. so much for the aluminium associations.( danger will robinson ! )