Any material science people? Need a durable hand-malleable metal recommendation.

[fuzzybabybunny]

I've got a friend who is making a product that needs to have a thin flat sheet of material (~1mm thick) that is easily malleable by hand (into, say, a U-shape) at room temperature and which also retains its shape once bent. The product is only the size of your hand.

Currently he has tried a sheet of tin, but tin actually disintegrates into little particles when it's folded and bent around a lot.

He also has tried lead, but while the malleability is good, he's concerned with long term health issues.

Can anyone recommend other metals or alloys he can try?

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[zinfamous]

maybe tungsten? It's very strong but also rather malleable.

 

[lxskllr]

maybe tungsten? It's very strong but also rather malleable.

Eh? Tungsten's very hard and brittle. I'd look into copper.

 

[zinfamous]

Eh? Tungsten's very hard and brittle. I'd look into copper.

not pure tungsten, though. but there's the rub--getting some pure tungsten.

 

[SKORPI0]

Aluminum, then either precipitation or age hardening.

 

[monkeydelmagico]

https://www.americanelements.com/silver-copper-zinc-tin-alloy

I'm not a materials engineer so not sure this will meet needs. The good news is this company does have engineers available for consult.

 

[HumblePie]

Aluminum, then either precipitation or age hardening.

Was going to reply Al as well, but someone beat me to it. I just used some chain fence ties this weekend which are hand malleable aluminum.

 

[fuzzybabybunny]

Aluminum, then either precipitation or age hardening.

What would happen if we just got aluminum foil and folded it tightly on itself like 20 times to make a 20-layer thick sheet of aluminum foil?

Would such a thing withstand thousands of cycles of being hand-bent back and forth between a U-shape and flat sheet? Would it disintegrate like the tin sheet did?

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[herm0016]

probably copper. but all metals will work harden and become brittle. if you use carbon steel you can keep heating it and taking out the temper. heat it to red and very slowly cool it.

aluminum work hardens very readily.



lol....thousands of times? there is no normal alloy that will allow this. why not a low temp thermoplastic? foil layers will not hold up, as the outside and inside sheet will be different radii and create issues with the shape and layers, its also has little sheer strength and will work harden quickly like all aluminum.

 

[dullard]

Was going to reply Al as well, but someone beat me to it. I just used some chain fence ties this weekend which are hand malleable aluminum.

Aluminum doesn't have a fatigue endurance limit. Thus, even with small forces, aluminum will eventually fail when being bent. Steel does have an endurance limit. Thus, if you can keep the bending forces small enough (small enough stress), you can theoretically bend it an infinite amount of times.

https://en.wikipedia.org/wiki/Fatigue_limit

But, you aren't going to be bending 1 mm steel by hand. Does it need to be 1 mm thick?

 

[mxnerd]

Galvanized steel sheet? Probably not easy to bend though.

https://www.youtube.com/results?search_query=bending+steel+sheet

===

Err, did not notice that thousand times bending requirement.

 

[dullard]

why not a low temp thermoplastic?

Yes. Polyethylene and polypropylene are probably the best common plastics for this purpose (look up "living hinge").

 

[fuzzybabybunny]

OK, so metal sheets are out then if they all eventually become brittle.

As for thermoplastics, I would need this sheet to easily work into and maintain a U-shape on its own at room temperature. In fact, it should maintain any shape out its own. The thermoplastics I'm familiar with in daily life always want to spring back into its original form, at least to varying degrees. I don't want it to spring back hardly at all.

I'm also considering silicone-based putty that never dries out and even magnetic beads.

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[herm0016]

WTF are you making? Maybe we can help you design something that is not just theoretically possible, but possible with current materials science and physics laws.

 

[ctbaars]

Wait ... Thousands of cycles? Seriously ... Like a hinge. And some hinges have a problem with "thousands" of cycles.

 

[HumblePie]

What would happen if we just got aluminum foil and folded it tightly on itself like 20 times to make a 20-layer thick sheet of aluminum foil?

Would such a thing withstand thousands of cycles of being hand-bent back and forth between a U-shape and flat sheet? Would it disintegrate like the tin sheet did?

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Yah, but the OP didn't say it didn't require an endurance limit. If he said he wanted that, I would probably throw out gold... but I don't think he wants to go that far.

 

[dave_the_nerd]

What would happen if we just got aluminum foil and folded it tightly on itself like 20 times to make a 20-layer thick sheet of aluminum foil?

Would such a thing withstand thousands of cycles of being hand-bent back and forth between a U-shape and flat sheet? Would it disintegrate like the tin sheet did?

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Thousands? No - pretty much any metal would fatigue/weaken and split under that kind of stress.

Sounds like the product needs some design review.

 

[Carson Dyle]

What sort of metal do they use in tie wraps?

I used to keep all of the flat package wraps that came with saltine crackers, back when I bought saltines. I use them for closing bags like those for frozen vegetables. They're just flat plastic pieces with two parallel wires embedded in them. Some of them are probably close to 30 years old and I know I've used them many hundreds of times. They don't get twisted like a tie wrap, just folded around the bag opening.

 

[RLGL]

You need a hinge nothing as a solid will stand up to that usage

've got a friend who is making a product that needs to have a thin flat sheet of material (~1mm thick) that is easily malleable by hand (into, say, a U-shape) at room temperature and which also retains its shape once bent. The product is only the size of your hand

Why not have your "friend" talk to an engineer. what you want is probably either next to impossible to find or absurdly expensive

 

[HumblePie]

What sort of metal do they use in tie wraps?

I used to keep all of the flat package wraps that came with saltine crackers, back when I bought saltines. I use them for closing bags like those for frozen vegetables. They're just flat plastic pieces with two parallel wires embedded in them. Some of them are probably close to 30 years old and I know I've used them many hundreds of times. They don't get twisted like a tie wrap, just folded around the bag opening.

an aluminum alloy

 

[herm0016]

going further, the plastic keeps the radius large enough that they continue to work. Good idea, you could make a sheet with maybe 5 wires in it and the plastic.

 

[Carson Dyle]

I suspect that the wire radius has as much or more to do with the bend radius. The nice thing is that if you were manufacturing them, you'd control the gauge of the wire you use. Another nice thing (maybe... if the OP would give us a clue about their use) is that it would weigh a fraction of what something similarly sized and made from a solid piece of metal would weigh.

 

[mindless1]

I vote (woven?) copper matting, laminated if this needs to be completely smooth. High flex wire can easily withstand thousands of bend cycles if the bend radius is large enough. Then again it's not the best for retaining a bend, these two properties are at odds with one another.

 

[Fenixgoon]

I've got a friend who is making a product that needs to have a thin flat sheet of material (~1mm thick) that is easily malleable by hand (into, say, a U-shape) at room temperature and which also retains its shape once bent. The product is only the size of your hand.

Currently he has tried a sheet of tin, but tin actually disintegrates into little particles when it's folded and bent around a lot.

He also has tried lead, but while the malleability is good, he's concerned with long term health issues.

Can anyone recommend other metals or alloys he can try?

Sent from my SM-G900T using Tapatalk

like everyone else has said, what does your friend need this U-shape to do? What size u-shape does he need? define "retains shape well" - is this thing going to be flexed and loaded or is it more ornamental? if loaded, where are the loads?

to start with, i'd either go with some 1000-series aluminum (super easy to form) or some annealed 301/304 stainless sheet (stronger, but still easy to form). both should be relatively easy to acquire. don't buy shim stock, as that will generally be hardened (cold-rolled) and less ductile. you shouldn't have as much an issue with sprinback for steel vs aluminum or titanium due to steel's higher elastic modulus.

funny story about the tin - what your friend is doing is causing the tin to change from a body-centered tetragonal (BCT) phase to a diamond-cubic phase. the atoms are literally rearranging themselves as he's bending it. this results in a huge expansion at the atomic level (~27%) that results in the disintegration.

anyway, more details will help us help you better

 

[HumblePie]

like everyone else has said, what does your friend need this U-shape to do? What size u-shape does he need? define "retains shape well" - is this thing going to be flexed and loaded or is it more ornamental? if loaded, where are the loads?

to start with, i'd either go with some 1000-series aluminum (super easy to form) or some annealed 301/304 stainless sheet (stronger, but still easy to form). both should be relatively easy to acquire. don't buy shim stock, as that will generally be hardened (cold-rolled) and less ductile. you shouldn't have as much an issue with sprinback for steel vs aluminum or titanium due to steel's higher elastic modulus.

funny story about the tin - what your friend is doing is causing the tin to change from a body-centered tetragonal (BCT) phase to a diamond-cubic phase. the atoms are literally rearranging themselves as he's bending it. this results in a huge expansion at the atomic level (~27%) that results in the disintegration.

anyway, more details will help us help you better

He is a material's engineer. I know stuff, but just dabble But glad I was basically right.