Best References/documents RE: Superplastic Forming [SPF] of Aluminum Alloys 2004, 7475 Etc??? 1

[WKTaylor]

A question has arisen regarding a difficult to form aluminum alloy part: a deep/wide/long U-channel that twists and converges.

1. There is a desire to make this as a 1-piece, so SPF aluminum was proposed... which is what customer is interested in. However initial attempts to SPF this part are non-productive.

2. Now exploring a wide-range of fab options.

Would it be better to... ??

try SPF [alloys noted] as a one-piece, but using 'a hybrid' of other procedures?

or SPF [alloys noted] as 2-halves which are then joined together by Friction Stir Welding [FSW]?

or better to break it into multiple [more conventionally] formed segments in standard/conventional alloys which are then joined together by FSW?

or perhaps change to another fab method or alloy entirely such as segmented precision die castings or forgings [joined by FSW]; or perhaps a large precision machined thin-walled part [out of thick block]; or perhaps good-old drop-hammer forming?

or perhaps go-to another [thinner] material such as 6Al-4V sheet?

3. For now, I am just trying to get my feet on the ground regarding SPF of complex parts. What references/documents/texts are out there for advanced SPF of complex/weird parts like this?

Sorry... due to the nature of this beast, I can't show any 'configurations'.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[rb1957]

I hate to say it to someone so respected, but have you tried to google it ? "superplastic forming" got a bunch of interesting hits

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

 

[WKTaylor]

RB... This hurts my head...

Been thru a bunch-of-those 'superplastic forming document hits' on the internet and company intranet. Almost-all [documents, etc] seem to be endless looping R&D related: investigated this, developed this, making these parts like this, tested this, make-this detail like this, etc... NONE appear to have concise/wide-ranging design/analysis related materials, discussion, recommendations etc.

NOTE.
'Hunting this ghost' is driving me crazy: a superplastic forming technology design guide/manual/handbook/text, related to current materials and developing real-world parts! Over the years I've found design data/documents/guides/manuals/handbooks/texts for most important subjects such as conventional forming practices, adhesive bonding, forging, casting, structural repairs, fasteners, machining, etc... but NOT this particular subject.

I'm hoping someone 'out-there' has stumbled across what I'm looking for and remembers** where it is.

**Over the decades I have stumbled-on, read, saved, then forgotten/lost/had-stolen where/what I saved-it/found-it... way-too-often!



Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[rb1957]

apologies, should've figured you'd've done your homework first !

Yes, I'm not seeing much (in the way of design guidelines) quickly either ...



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

 

[WKTaylor]

RATZ...

NOTE.
I have run across one that 'looks like a text book' but was shaking my head after checking the index: looked more in-line with research than for 'dumb old ROT engineers' like me. Perhaps if I could get my hands on a copy [company library does not have a copy], or talk with someone who has a copy and knows its depth, I'd have a better feel for it. At $170/copy I'm not inclined to just 'buy-it-to-try-it'...

Superplastic Forming of Advanced Metallic Materials: Methods and Applications

https://www.amazon.com/Superplastic-Forming-Advanced-Metallic-Materials/dp/1845697537

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[TimMcK_Aero]

Have you tried DTIC?

 

[Compositepro]

There was a great deal of interest and government support of superplastic Al forming for the F-22 Raptor program. Since those days I've not heard much about the process. I do remember that Supperform was one company involved. I think the technology was limited by the alloys that could be used and the geometry of the parts where it could work.

 

[berkshire]

Will,
Without being able to see what you want to produce, is a bit like shooting in the dark. however "the phrase deep/wide/long U-channel that twists and converges." reminds me of some weird stringers I have produced in the past. made by preforming channels in a press brake then stretch forming to final contour on a segmented stretchform die that was dis assembled to remove it from the part. Does this give you any ideas ?
I am most likely too long in the tooth for this, but the phrase superplastic reminds me of " High energy rate forming" Where the part was formed so quickly it heated up enough to become plastic. British aerospace did a lot of research on that.
B.E.

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

 

[rb1957]

yes, I recall BAe used it for access covers on their Airbus wings. But I suspect there's a lot of trail and error and the reports will be like others Will has found ... very general, not design guide-lines. Maybe your best bet is trying to talk to a company that does it, but I doubt they'll open their data vaults to you.

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

 

[WKTaylor]

TimMcK...
DTIC is my 'go-to' for MIL/FED documents [along with ASSIST, NASA/NACA and of course SAE, AIAA].
NOTE. DTIC is a royal-pain to search [poor search engine]: HOWEVER, Google searches include [unclassified] DTIC content and work better at finding useful subject matter documents!?!?

Compositepro...
Yes... a VERY limited variety if materials can be SPF [or SPF-DB] for a host of reasons I'm just becoming familiar with... especially aluminum.

Berkshire...
The configuration is far weirder I am at liberty to explain and You can imagine. For some reason customer is 'stuck-on' using ~0.090-thick 2004 sheet, formed by SPF then HT to -T6. Pretty straight forward concept, except test parts are badly distorted and straightening to typical Assy tolerances appears impossible.

RB1957...
I have an emerging 'strong feeling' that high value SPF Design Guides/Manuals/Handbooks ARE jealously guarded by the OEMs/vendors; and that the DoD/Fed may have design guides which are classified for national defense purposes and/or proprietary corporate-data reasons. Highly useful [secrete-handshake] SPF texts/manuals/HDBKs may not truly emerge for years [other than the one I noted above!?]. DANG... I long for the days when AFWAL did basic research that was more accessible to us mere mortals.

All.... some of the R&D reports, and my other experiences, are starting to ‘highlight’ hybrid ways that the channel can be made, put-together and straightened after HT which I'm not sure I should discuss in depth; however following are potential additive processes [abbreviated only].

SPF
FSW
HT + HT ‘W-CF' + LSP

This is gonna drive me to drink s’more Crown Royal.





Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[berkshire]

Will,
Would it help to go talk to somebody who does this kind of work like Missouri metals St louis for example.?
B.E.

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

 

[WKTaylor]

Berkshire... YEAH I though of contacting vendors... however...

I was asked for independent assessment on this topic area, due to my un-typical fab/manufacturing and service-experience background. Years ago I was indirectly involved with T-38 MLG doors made from SFP-DB Ti.

I am not allowed to directly contact vendors for many contractual reasons.

'Feels sorta cheating' by putting this on Eng-Tips... but the 'broad question' without specifics is not over-the-line [my story, sticking-to-it'].

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[tbuelna]

WKTaylor,

There is quite a bit of SPF information on the DTIC and NTRS websites, but most of it is related to hard to form materials like titanium. If you are forming aluminum sheet material you might look at hydroforming techniques, which are somewhat similar to SPF without the application of heat. Hydroforming sheet only requires a single mold surface like SPF, but the forming pressure is applied using a rubber diaphragm.

 

[berkshire]

Will,
Since the part you are describing is a form of channel. Does it really need the elongation of Superplastic forming.
Or is this a method somebody else has suggested. I do not know how long your part is and most likely I don't "need" to know.
Knowing your back ground, I can presume you have already looked at matched tool forming, drop hammer, stretch and stretch wrap forming.as well as super plastic. Hydroform may have size limitations , however a Verson Wheeler press can accept parts up to 10'-0" long, and you can use draw rings on the tooling to get a sharper draw. I am just throwing this out there .
I realize the pain of trying to get information when you cannot tell anybody what you are doing.

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