Type of welding to be used

[autogyro]

Is this a joke? Even if you could... why would you want to weld Al and Steel together?

I once knew a welder who claimed she could weld a cat's ass to a windowpane, so a three-way joint between carbon, steel and aluminum should be nooo problem!

You just need a different nozzle and a left handed spanner to tighten it.
I think you can melt carbon fiber. You just need an inert atmosphere and a very, very high temperature.
I will ask the BOC guy next time I see him.

[flynfrog]

you may laugh but my office mate down the hall has a chunk of stainless tube welded to al tube. He said its used in space aplications where you have an AL cryo tank with SS tubes.

[Giblet]

Is this a joke? Even if you could... why would you want to weld Al and Steel together?

If I can weld a steel bracket to my aluminum or chrome molly bicycle frame, I won't have to keep wrenches in my backpack when I ride it to tighten clamps on the generally tapered bars of bikes. Using screwes and clamps makes keeping these rides tight prety difficult as the motors and chain really shake the frame. The rigid frame gives no butt isolation and stuff shakes loose.

If I knew this could have been done I would have saved myself some stitches and road rash in my moronic quest to kill myself on a bicycle.

[marcush.]

Melting point of carbon :3800+ K +

welding Wood:

http://www.zeit.de/2007/24/T-Holzleimen

welding carbonfibre to aluminium sheet and aluminium coated steel by ultrasonic metal welding -2008:

http://www3.interscience.wiley.com/jour ... 1&SRETRY=0

So I´d say : fact not opinion ,not yingyang.
Took me 5 minutes to googleactually ,surprising nobody did this already.

So we are all bloody useless in terms of what is done already in this world .I will never lough off a seemingly silly question like can you weld steel to carbonfibre?

Yes you can.

[RacingManiac]

why would you "weld" carbon fibre to metal if there are epoxy made specifically to attached prepped metal to composite.....

Giblet, you can weld steel bracket to chromo frame, chromo is just a type of low carbon steel.....and its consider relatively weldable...

Although I think there are processes for actually industrially welding aluminum to steel(friction, or even explosive), for most purpose it probably is a lot easier to just design a properly bolted joint....

[riff_raff]

Widely different materials such as aluminum, steel, ceramic, glass, etc. can be thermally brazed or adhesively bonded to each other, but not welded.

Slightly different metal combinations, such as stainless steel to alloy steel, can sometimes be fusion welded or friction welded. And other metal combinations, such as copper and alloy steel, can even be diffusion bonded (which is a type of welding).

But regardless of the joining process (brazing, adhesive bonding, etc.) you use, whenever you are rigidly attaching two materials to each other with dissimilar galvanic potentials, elastic moduli or thermal expansion rates, you are likely going to have trouble designing a satisfactory and durable joint.

By the way, the only conventional metal that gives satisfactory results in contact with carbon composites or pure CRC's, is titanium.

Regards,
Terry

[marcush.]

Widely different materials such as aluminum, steel, ceramic, glass, etc. can be thermally brazed or adhesively bonded to each other, but not welded.

Slightly different metal combinations, such as stainless steel to alloy steel, can sometimes be fusion welded or friction welded. And other metal combinations, such as copper and alloy steel, can even be diffusion bonded (which is a type of welding).

But regardless of the joining process (brazing, adhesive bonding, etc.) you use, whenever you are rigidly attaching two materials to each other with dissimilar galvanic potentials, elastic moduli or thermal expansion rates, you are likely going to have trouble designing a satisfactory and durable joint.

By the way, the only conventional metal that gives satisfactory results in contact with carbon composites or pure CRC's, is titanium.

Regards,
Terry

please follow my aforementioned link :
http://www3.interscience.wiley.com/jour ... 1&SRETRY=0

this is not folklore its a issued paper ,it is welding by definition so basically you are wrong as proof is evident ,end of story.
I only make this comment because I as well had exactly your perception of the
matter before i found that paper.

[ringo]

Shouldn't a weld be homogenous, or the idea that the work pieces are melted then fused?
This looks more like a composite in the sense that the fibers are still distinguishable from the metal.
However it still answers the question of bonding Al to CFRP.

[marcush.]

bonding of course needs to apply a substance -glue, resin or spit .....
soldering also does not melt the the pieces to be joint so should be counted towards bonding -thermal bonding maybe-
Welding is a process where no substance is added to the pieces joined -but the two pieces are permanantly joined with no clearcut joining surface.For years the process of welding plastics -thermoplastics -is well known ...no adding of meterial permanent joint.Also explosion welding let materials join that would not meet very friendly with conventional methods...
so discussing what is welding and what is not is in my view a different topic altogether .
Fact is ,the group in germany has developed a process wich is under the broad view what does make a joint a weld clearly qualifies as such.
Of course you can argue what does this mean in terms of relevance to all of us in the field ..possibly nothing for this time ,just because you will not even consider something like that in anything you are likely to be involved with in your life ,as the money to make a process like this manageable will most likely not fit the recources available...so nice to know but thats it really.The true art is to do your designs in a cost effective way ,not to overcomplicate and event tricky thngs nobody else could do.the trick is to keep it simple and let the design and concept take care of the high demands of your application.honestly speaking not many people in the industry seem to follow this principle but tend to be technicfreaks toying their babies..but ..