Can you provide more details of the 3D contour you need in the formed part? Does it need to have a uniform thickness after forming? What is the accuracy you require in the formed part? Is there a requirement that the part must be machined from a formed/forged material stock?

The first thing that comes to mind is that it seems like it would be much easier and faster to simply CNC the contours you need from a thicker piece of 7050 raw material. 7050 aluminum plate and 3-axis CNC machine time are relatively cheap compared to what it will likely cost to have this piece of 200mm plate forged to shape.

"forming" 8" thick plate !!???

can you buy 8" plate billets ? maybe, but I'm not sure you can get them 4' x 4' ?

what forming exactly are you considering ?

another day in paradise, or is paradise one day closer ?

Tbuelna..
I have attached the picture for the contour reference. Accuracy doesn't matter this shall be machined later on as well on worst case. looking forward to hear your suggestions and thanks for your answers.

• http://files.engineering.com/getfile.aspx?folder=a9ae36e5-377b-46df-a0f6-13

First, I would contact Alcoa.
Contact Information
Davenport, IA
United States
800.523.9596

Is the limitation that the material is not available in the thickness required?

It looks like a lot of cost and processing to form the plate a little bit. You'll probably have to anneal and may have to hot-forge, and then have to stress relieve and then heat treat to get the properties back without having the part warp from the internal stresses from the bending process.

Bending may not be a big savings over getting a forging die made that produces 90% net shape.

research hand forged billets. you can get billets curved the way your piece looks to be, then 5-axis machine it. remember to shot peen after machining.

another day in paradise, or is paradise one day closer ?

adding to 3DDave's comment...

Contact ALCOA or ALCAN... they both have capacity to make forged-curved-billets [7050-T7452], or possibly stretched-curved [-T7451] plates, like Your illustration in known/tested heat treat/strain states. May also wish to consider following thick section alloys/tempers Ref MMPDS-08

7050-T7451 AMS 4050, radiused-bowed plate, stretched ~3% during forming, up-to 8.0" thick [ALCOA, ALCAN]
7050-T7452 AMS 4108, 'hand-forged', up-to 8.0" thick [ALCOA, ALCAN]
7085-7452 AMS 4414, 'hand-forged', up-to 12.0" thick [ALCOA]
7040-T7451, AMS 4211, radiused-bowed plate, stretched ~3% during forming, up-to 8.0" thick [ALCAN]
7140-T7451, AMS 4401, radiused-bowed plate, stretched ~3% during forming, up-to 8.0" thick [ALCAN]
7140-T7651, AMS 4408, radiused-bowed plate, stretched ~3% during forming, up-to 8.0" thick [ALCAN]

ALCOA, ALCAN - aerospace aluminum, plate and forged billet, alloys noted.

I have various for all above, but will not list them, this forum.

NOTE.
Boeing purchases these alloys.. especially 7040 and 7041... in significant quantity and at deeper sections than allowed per AMS Specs [per BMS material specs].

NOTE for those who may be inerested: 7136 alloy extrusions can be purchased in -O temper [Boeing BMS not AMS] and can then be solution HT/Quenched, stretch-formed in the W temper, then PA to -T762 temper [BAC HT Spec?]. V Good mechanical/durability/EXCO/SCC properties!? Alternate for 7075-T6 and 7178-T6 extrusions!!!!???? I wonder if AMS specs [and MMPDS] will ever catch-up with BMS/BAC, this alloy/temper.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true.
o For those who believe, no proof is required; for those who cannot believe, no proof is possible.
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion"]
o Learn the rules like a pro, so you can break them like an artist. [Picasso]

Thanks!!
Wil Taylor

koodsg-

The image you provided was a bit fuzzy, but it looks like this is some sort of frame structure. It appears that the center of the frame is open on the concave (IML?) side, but I could not tell if it was also open on the convex side. As others noted, there are a couple options you have for forming the raw material into a shape that gives the best compromise of material properties, raw material cost, and processing cost. However, you have not mentioned what application the part is used for, or if there are any requirements covering the raw material form the part is machined from. Do you want to use a formed piece of plate primarily to reduce machining time and reduce material scrap?

Your two most likely options are hand forging or roll forming. Neither process requires special tooling. There are a few machines capable of cold rolling your 8" aluminum plate to the curvature you show. But there are many more forging houses than can produce a hand forging to your specs. Here's a quick read that discusses rolling versus hand forging of thick aluminum plate.

ps. Once again an awesome post from Wil Taylor!

Regards,
Terry

koodsg... one minor point about Your post...

In the title You mentioned 220-mm [8.66-inch] thick material; yet in Your post You specifically indicated 200-mm [7.875-inch] thick material.

There is a huge/difference in these two thicknesses, especially for 7050. Per MMPDS-08 the limit thickness for plate and hand forgings [AMS4050 7050-T7451, AMS4108 7050-T7452] is 8.00-inch [203-mm]. Above the 8.0-limit [either spec], this gets into a murky world of 'non-spec material', 'customer-fabricator contract requirements', 'special production run', 'point design allowables based-on samples-testing', etc.

Take my word for it, out-of spec thicknesses [above or below] can be a nightmare for a one-off part... unless of course, Your company/vendor is already already doing this exact same material [fabrication by special contract or company unique material specification for the greater thickness]. I can thnk of a few examples of special production runs of over-sized material for unique parts that have gone thru this expensive and time-consuming process.

Example: special contract for hand forgings deliberately made up-to to 12.0-inches [254-mm] thick in the -O or -O1 ["oh" or oh-one... NOT "zero" or zero-one] temper; to be HT to -Txx, after machining below XY thickness, by special process Z. Special 'lot testing required': metallurgical examination of the of the block grain; evaluation of response to heat treatment as specified by contract]; checks for hardness, conductivity; testing for mechanical allowables and fracture toughness; corrosion and SCC testing; etc. Gives me the-sweats just thinking about this.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true.
o For those who believe, no proof is required; for those who cannot believe, no proof is possible.
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion"]
o Learn the rules like a pro, so you can break them like an artist. [Picasso]

yes, but you can establish your own spec with whoever is forging the billet for you. Add test pieces to the billet and test each other. Your spec should explain where to cut the specimens (outside of the volume needed for your part) and how to test them. Your spec should also have a minimum strength required (something negotiated with the vendor). Your static and fatigue test airframes will establish the performance of your part given that it meets your spec.

another day in paradise, or is paradise one day closer ?