Folding with T3 Aluminium! 3

[var10]

Hi guys,

Folding T3 aluminium as shown in the figure is it really that hard? I can see it will be different to that of o-condition al. But achieving the indicated dimension is it possible. Another supplier issues with folding this. They tried using bend radius 1mm did not work and had to changed it to 3mm which he reckons will be taken from the o/all dims to compensate if the highlighted one is to be achieved.

I have been reading up on folding processes and techniques to understand this. They have cut everything first thinking 1mm bend radius will work and when parts cracked he had no other choice but to change the bend radius. Still reckons it is very difficult to be folded.

My question,

T3 Aluminium - foldable or not?

 

[MikeHalloran]

2024-T3 is almost magical as far as aluminums go.
Its yield point is higher than some steels,
and it machines like a dream.
Bending is one thing it doesn't do well.
Resist corrosion is another; that's why the alclad variant came to exist.

Consider a different alloy.
Parts like the one you have illustrated are commonly made from 5052-H32.
... With tight corners. Or 5052-H34 with less tight corners.






Mike Halloran
Pembroke Pines, FL, USA

 

[var10]

Thank you Mike. I am a bit disappointed that the manufacturer did not pick this up before and we have to re-produce this.

 

[MikeHalloran]

2024-T3 is available in a number of Imperial sheet thicknesses, traditionally used for flat or gently curved aircraft structure including doublers and triplers.

It's also available in thicker billets, so there may exist the possibility of machining your part from a solid bar with no bending.

It seems crazy, but a CNC mill with a fast spindle and/or a large cutter can go through 2024-T3 like butter, and produce the part at a nearly competitive cost.
The only downside is that chips will be _everywhere_, including stuck to the ceiling.



Mike Halloran
Pembroke Pines, FL, USA

 

[berkshire]

var 10,
from table 4 page 221 of forming Alcoa Aluminum. Min forming radius for 2024-T3 sheet: Less than 1/64" 1.5 to 3 T , 1/32" 2 to 4 T , 1/16" 3-5 T.
The min bend rad for 2024-0 is 0" so the part can, be formed, by heating, and quenching it, forming it in the AQ temper, hand straightening it, then aging it back to the temper you want. This also means, that you have, to have this done, by a shop with heat treat capability.
B.E.

You are judged not by what you know, but by what you can do.

 

[drawoh]

var10,

I have seen 19" rack enclosures bent up from 2024-T3. The bend radii were large, as required. The parts appear to have been cut out with a nibbler. This was probably all done in an aircraft hangar somewhere.

As noted above, 5052-H32 is a standard aluminium grade for sheet metal. 2024-T3 is really exotic, and you should chat with your sheet metal shop before using the material, and/or letting them do the fabrication.

--
JHG

 

[var10]

Thanks a lot everyone especially berkshire. If its not too much to ask can anyone share forming alcoa aluminium book? Thanks again.

 

[dvd]

You might try having the blanks cut at 90 degrees from the current direction. The rolling direction has an effect on whether the bends will crack or not. If that doesn't work try 45 degrees. If that doesn't work try something in -O condition (6061?).

By the way, do you have mill certs on the material? Have you checked hardness to see if it seems to be 2024-T3?

 

[berkshire]

VAR 10,
There is a used copy on Amazon right now,

http://www.amazon.com/gp/offer-list...g_used_olp_sr?ie=UTF8&condition=used&sr=&qid=

It is an early edition, about the third or fourth printing.
B.E.

You are judged not by what you know, but by what you can do.

 

[berkshire]

Var 10,
There is a later copy available for about $ 28.00 also on Amazon.
B.E.

You are judged not by what you know, but by what you can do.

 

[rb1957]

typical practice is 3t bend radius (I can't read your pic).

if you form in O condition and later heat treat to T3 (or T42) you can get tighter bend radius.

Quando Omni Flunkus Moritati

 

[IFRs]

According to The Aluminum Association, Table 3-1 in section VI of the Aluminum Design Manual, the recommended minimum bend radius for 90 degree cold bends in 2024-T3 sheet is 2.5T for t=.0156 inch, 3T for .03125, 4T for .0625, 5T for .125, 6T for .25, 7T for .375 and 7.5T for .500.