cold forming of Al7005 plate

[darcyo]

hi there, i was just wondering if anyone out there has any working experience with cold forming Al7005 plate. I am worried about lamellar tearing while bending in the annealed state. Any suggested heat treatments prior to forming/bending? can it be done? Maybe i can substitute 7005 with a silica rich Zn-Al alloy (that is weldable)?. Any assistance would be much appreciated.
D'Arcy O.

 

[unclesyd]

I have 3 books on forming Al. All treat extruded 7005, a heat treatable alloy, the same way. The only mention in my books is for two tempers of the alloy and they are -O-and -T53-. Base on the difference in YS of 7005-O at 12 ksi and T-53 at 50 ksi I would assume that the -O- Temper is the one to form. The only mention of forming is that the alloy is slightly less workable than 6061, with no mention of temper. You could look at tables for 6061 to get some idea of what radii are possible, in others words stay under the 6061 radii while bending.

The alloy has a slightly higher modulus than 6061 (10.0 vs 10.3), which could account for the difference in formability.

The numbers for the alloy are:
T-O UTS 28 ksi: YS 12 ksi: El 20%
T-53 UTS 57 ksi: YS 50 ksi: El 15%

All references to welding reference the T-53 Temper.

There are several references in the information on bending extruded Al and the use of "crush bending" with the proper lubricant. There is no additional information other than it shows 90° bends with small radii.

I would get with your suppliers and see what is available as the availability of some alloys and cross sections are a little hard to come by at times.