Alloy - Changing the Temper

[Randy V]

Guys,

I have piece of 2024-T3 .090" sheet that is literally perfect for the project I'm working on. However, I need to bend it 90 degrees in my Roller-Brake with a 3/4" radius. The two bends are to be 9" apart from one another and parallel.

Bu using liberal heat and a lot of BEEF I have made one bend, but need to make the second. The piece is now no longer long enough to clamp in the brake by normal means (which was barely sufficient to make the first bend) and so I will need to rig up another means to clamping. Certainly the rigged clamps won't be as stout as the ones on my bender.

SO

What I would like to do is to soften up the metal sufficiently where I can make this bend without requiring herculean strength to do it..

I've softened up other alloys in the past by heating and then quenching. This stuff seems to retain it's strength quite well... Unfortunately..

Any tips for me?

I'd really like to get this project knocked out this weekend and with recent health issues I can't drive to go find more material..

Thanks in advance...

Alloy info;

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA2024T3

 

[Ivan]

any chance of a pic m8?

 

[Dave Lindemann]

......with recent health issues I can't drive to go find more material..

Randy -

Sorry I can't help with the metallurgy question but I wish you well with your health issues.

Take care of yourself,
Dave L

 

[Scott Calabro]

Randy,

I don't think you will have much luck annealing that alloy, AAYRMV.

Check this forum out;

http://www.eng-tips.com/viewthread.cfm?qid=64136&page=193

For full anneal (to T-0 temper): 2-3 hours at a metal temperature of 775<SUP itxtvisited="1">o</SUP>F (413 C), followed by slow cooling at 50<SUP itxtvisited="1">o</SUP>F/hr to 500<SUP itxtvisited="1">o</SUP>F. Faster cooling thereafter is permissible

5052 sheet is great for just about anything fabbed on a GT40.

What the heck though give the torch a try.

S

 

[Jac Mac]

Make life easy for yourself Randy & use 5052 or 5086. 2024 anything is no good for welding & even your efforts with the torch so far have probably created havoc with its qualities already.

 

[Randy V]

Scott - Thanks for the link and the info - I'll probably have to give it a try...

Jac - I'm sort of stuck here. Can't drive right now. I don't have the correct alloys / pieces..

Ivan - Pics below.

Dave - Seems that I have this rather large growth inside my head called an Arachnoid Cyst. It's a couple inches long/wide. I see the Neurosurgeon on Monday. All this was found when doing an MRI to find out what is triggering seizures of a malady called Trigeminal Neuralgia. Excruciating pain that we're lucky to have under control right now with drugs. It will, however, require surgery as far as I'm told - unless I want to live on these drugs for the rest of my life.

Anyway - enough of that as I'm sure it's not near as fascinating as working in my shop..

Here's some pics. I won't say what the piece is until it's done - but I would REALLY like to get it done yet this weekend if at all possible..

I have an Acetylene torch and bottles are full - but I don't think I'll be trying to keep it at 775f for 2-3 hours... We'll have to give it a try for 30 minutes and see if it takes enough of the strength out of this stuff to allow the second bend..

 

[Cliff Beer]

Randy, if you have a hydraulic press you might be able to bend that into shape w/o too much effort. Just use a round "die" in the right diameter on the top of the alloy and get a compressable rubber mat underneath and start cranking. As the die presses down onto the alloy it will depress into the rubber and bend around the die very nicely. It's sort of like a redneck version of a full size machine brake press.

I've bent some nice stuff this way and it's very simple and easy.

Also, if you want to soften up that 2024 then heat it but let it cool slooooooowly.

 

[Phil]

Randy:
I regularly bend alloy alum with t-6 temper, just use your torch and be careful as the temperature between what you want and the material drooling away in a puddle is critical. I usually try to get the color to change to a slightly darker gray, and try to keep the torch far enough away from the material so as not to scar it with a local hot spot. Try the technique on a waste piece first. I recently bent some 6061 T-6 1/4" plate for a job this way with no cracking. The formula for bending alloy such as 2024 0r 6061 is generally to have the bend radius 3X the thickness, and from your photos it looks like you are well beyond that. The sheet will dissipate a lot of heat so it may be a bit difficult to heat it uniformly, and whatever you use to make the bend should be able to handle the temp. Try heating the material and letting it cool slowly as quenching will make it brittle and bring you back to your problem.
Another note on alloy aluminum is that it will age harden so don't worry about bringing it back to temper after your piece is fabricated as it will harden on its own.
Hope some of this helps
Phil