Forming aluminium

[ajack1]

As more companies move over to aluminium body panels, I am sure others will have encountered the tooling problems that this creates.

The other day we came across a company that does superforming. Despite it still being to expensive for the mass producers some of the things they can do is mind-blowing, check out some of the links.

http://www.superform-aluminium.com/technical/technical-summar.html

 

[ornerynorsk]

How does this differ from hydroforming, which can be done cold? Looks interesting.

 

[NickE]

ornerynorsk- I think that ajack1 is talking about super-PLASTIC forming. This process can generate elongations of >1000%. (it just is not possible at room temps.) My advisior in grad school did this with Ti sheet to manufacture airplane propellors. Three sheets of Ti alloy were clamped together with a resist betweeen them. They were then heated and a inert gas was used to pressurize btw sheets 1/2 and 2/3. the resist would be different on each side and the airfoil shape was created by the mold that contained the whole assembly. In one step the airfoil was formed and the internal rienforcement created.

You might wnat to google:
superplasticity or superplastic forming

 

[Hydroformer]

That IS some SUPER-plastic forming. The process seems to be more along the lines of blow-moulding although very close to sheet hydroforming. The different methods they show (cavity, bubble back & diaphragm) can all be applied in hydroforming.

The main differences are material, forming media and temperature. The material needs heat (500F) to become 'super'-plastic, pressure and temperature differentials don't allow for the use of fluid as a media. However, the stretch rates achieved are phenomenal.

We stamp some aluminium here but our hydroforming is all steel, so I can't comment on any particulars with h-formed AL.

I suspect this is a very slow process and suitable for short-run production only (by automotive standards). Control of the draw using gas pressure (and probably hydraulic pressure for the binders or draw beads) must be a nightmare, given an expanding volume and trying to chase it with heated, pressurized gas. I wouldn't be surprised if there's actually a vacuum assist in the receiving tool for the final hhmmph!! to bring it home.


*Without data, you're just another person with an opinion.*

Hydroformer