carbon nanotubes to reinforce steel?

K

kaizo

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I was working in my lab today mixing carbon nanotubes (CNTs) and polymer and just wondered something. Has anybody tried mixing CNTs and steel to reinforce it? I don't know anything about metallology but I'm assuming martensite relies on carbon's reinforcement effect. CNT polymer composites uses the CNTs as a reinforcement much like steel struts in a concrete building. Amorphous carbon is known to have much less of a reinforcement effect than CNTs so this may be something that could be exploited...

Anyway this is purely out of scientific interest. There are a few roadblocks (sharpening/shaping CNT loaded steel would require extensive protective gear and therefore would have a number of health and safety red tape).

CNT-epoxy composite is most likely tougher than g10 or micarta so there may be milage of it as a grip there too.

And advanced apology if I have missed anything obvious. My field is carbon and I know almost nothing of metals and I just wondered if someone could kindly shead some light to it. Please let me know if this has been tried before or you think this may or may not work. Thank you for your help in advance. :)
 
This is an extremely interesting posit. I am quite curious to see what the metallurgy experts have to say.
 
Actually this is a pretty cool idea.

As a blade steel, it would probably suck. I'm no metallurgy expert, but there's gotta be something that would make it impossible (or at least mean that it would be less than ideal for an edge)

I can see it being used in composite blades in the spine steel for strength, while having a regular steel at the edge so that sharpening wouldn't be a problem. But then again, even as a "spine steel" it would need to be grinded and finished into shape, so the tubes might still pose a problem, if only during manufacturing.

I would love to see someone do some experiments to try this out, but sadly I don't see it happening any time soon.
 
If the carbon nanotubes can survive being mixed into 3000-degree F melted steel, and disperse themselves somewhat evenly like an alloying element, then I'd bet it would have a good strengthening effect. Grinding metal already creates hazardous fine dust and gasses, I'm not sure if the tubes are worse or if they would get vaporized during grinding or remain embedded in metal alloy dust or what.

Not to shit in anyone's cereal bowl or anything, but that article linked above barely even qualifies as pseudo-science. All it basically says is that someone looked at a damascus blade with an electronic microscope, and thinks they saw something that might indicate that there could maybe be some carbon nanotubes around some nano-sized metallic filaments within the metal.

"To Europeans, Damascus steel blades seemed magical. Not only could they cut a piece of silk in half as it fell to the floor, they could cleave rocks and their own swords without losing sharpness."

'Nuff said.
 
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Mecha said:
If the carbon nanotubes can survive being mixed into 3000-degree F melted steel, and disperse themselves somewhat evenly like an alloying element, then I'd bet it would have a good strengthening effect. Grinding metal is already creates hazardous fine dust and gasses, I'm not sure if the tubes are worse or if they would get vaporized during grinding or remain embedded in metal alloy dust or what.

Not to shit in anyone's cereal bowl or anything, but that article linked above barely even qualifies as pseudo-science. All it basically says is that someone looked at a damascus blade with an electronic microscope, and thinks they saw something that might indicate that there could maybe be some carbon nanotubes around some nano-sized metallic filaments within the metal.

"To Europeans, Damascus steel blades seemed magical. Not only could they cut a piece of silk in half as it fell to the floor, they could cleave rocks and their own swords without losing sharpness."

'Nuff said.
Click to expand...

Haha:D
 
I'm not 100% but our work with nano tubes in telecoms left us with the unsettling facts about how much of a carcinogen they are to humans
 
Krissig12 said:
Wait what? So all Damascus already has nanotubes?

Or only the ancient ones? :confused:

I'm so confused
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Couple things here - the ancient Damascus they are referring to here is totally different from modern Damascus. The ancient stuff is also known as Wootz Damascus (India made the steel and imported it to the middle east, where it was forged into swords), whose patterning came from chemical reactions during smelting rather than folding. It is currently believed that Wootz damascus was formed by a process similar to modern crucible steels. The odd mix of nanowires, nanotubes, and other structures give it the pattern and are likely the result of particular plant-based additives mixed with the steel, the specifics of which have been lost.

It's very cool stuff, and there's a fair bit of research being conducted trying to replicate it. I hope they succeed, it'd be super cool to have a reproduction of Wootz Damascus in a modern knife, even if its properties aren't as great as modern powder steels.
 
B34NS said:
I'm not 100% but our work with nano tubes in telecoms left us with the unsettling facts about how much of a carcinogen they are to humans
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You are correct. Pretty much any polyaromatic system ends up being a carcinogen. Fragments of the tubes can slide in between the base pairs of our DNA (where they become stuck due to pi-pi stacking) and cause problems with DNA translation and replication.
 
amg137 said:
You are correct. Pretty much any polyaromatic system ends up being a carcinogen. Fragments of the tubes can slide in between the base pairs of our DNA (where they become stuck due to pi-pi stacking) and cause problems with DNA translation and replication.
Click to expand...

Thank you all for the reply!

And indeed in fact CNTs structurally resemble asbestos and its a known carcinogen (although several publications suggest its much less toxic than asbestos). One thing I should note is that once immobilised by a host such as steel, concrete or polymer it is safe to handle and under current safety guidelines could even be handled without gloves once stabilised. In fact our research group is currently working on a PDMS-CNT composite to be used in vivo as a health sensor, thus be injected into a human body. Which brings us back to the point, sharpening. I personally would be happy to touch a piece of steel with CNTs in but not its shavings (as it contains micro/nano scale powders with aromatic rings in them that amg137 mentioned). Are there any parts of the knife that could benefit from hard steel other than for a composite knife and the edge?

I'm also very interested about the damascus steel and wootz steel does anybody have any info if this was for the whole steel or localised (such as the edge)? If it is for the whole steel I can't imagine it being good for the knife structurally. So far from what I have picked up in this forum a soft core and hard edge is what is desired (please correct me if I am wrong).

Thanks for the help! :)
 
That's more like it! :D ^^^
 
I'll try to straighten this out !
Sadly the " In " word is 'nano' and many research dollars go only to papers that use the magic word !!
The first article is bogus though the second one is much better though the metallurgists need some education about wootz !
The 'wootz' is a cast structure .The ingredients are put into a crucible and the reaction to create the steel which , as a cast structure is a dendritic [tree like ] pattern . The metal then is forged carefully to shape .However the dendritic structure is still there , though distorted because all the carbides are not homoginized because of the higher melting temperature of the Vanadium carbides. Wootz is a very labor intensive process to preserve the properties. The microstructures of wootz vs folded steel are different as shown it the second article , obvious to those trained in studying such structures . Wootz production ended when the vanadium rich ore was used up. When the proper alloying elements are there and proper proceedures used the wootz appears. !
Metallurgists can do anything ! Right Mecha ??
 
http://news.nationalgeographic.com/news/2006/11/061116-nanotech-swords_2.html

John Verhoeven, a metallurgist at Iowa State University at Ames who has worked on reproducing the Damascus sword-making techniques, is skeptical that Paufler and his colleagues have cracked the secret of Damascus blades.

"I don't think that [the nanowires] are anything unusual," Verhoeven said. "I think those structures would be found in normal steels."

Here's some more interesting stuff. It's ok to hate this, just tell us why you hate it.

http://archaeology.about.com/od/anc...-Mechanical-Structures-In-Damascus-Sabers.htm
 
mete said:
Metallurgists can do anything ! Right Mecha ??
Click to expand...

That's correct, Mete.

An image of a metallurgist commuting to work:

djNkbGf.jpg


I've read of several theories on why this culture or that rose to power based on metalwork conducted in an area where iron ores are rich in beneficial impurities (which are basically alloying elements). To understand how little of an alloying element it takes to drastically change the characteristics of a base metal, look no further than 1095 high carbon steel: around a mere 1% of added carbon changes the 99% of iron into cold, hard knife steel!
 
Regarding the second article, Shunsui:

I think the researchers would be less mystified by the metal they are scanning if they understood that has been beaten to hell and back by a blacksmith sword-maker, reheated and cooled many times, at various temperatures, in different seasons, at different rates, by different people, etc. It's going to host a whole kaleidoscopic range of irregular crystalline structures. Especially considering the dendritic nature of the wootz steel as described by Mete.
 
By the way , you should understand that metallography is a science in it's own right .Different techniques can yield very different results something experience is necessary.

We had an archaeologist come on Sword Forum once and she was confused about the bubbling of the steel in the crucible .But it's a chemical reaction and can be
"quiet" or "vigorous " . Nothing like a formal education but also nothing like experience --- have both !!

I'll get back to those papers later.
 
Mecha said:
That's correct, Mete.

An image of a metallurgist commuting to work:

djNkbGf.jpg


I've read of several theories on why this culture or that rose to power based on metalwork conducted in an area where iron ores are rich in beneficial impurities (which are basically alloying elements). To understand how little of an alloying element it takes to drastically change the characteristics of a base metal, look no further than 1095 high carbon steel: around a mere 1% of added carbon changes the 99% of iron into cold, hard knife steel!
Click to expand...

Indeed :) in fact if you mix CNT in an electrical insulator. 1% depending on how well its mixed turns into a conductor. Trace amounts makes all the difference!

Actually I think its probably worth noting that not all carbon are equal. Some of those carbon in steel may be fibrous but not necessarily hard. For carbon to demonstrate extreme toughness that adds to the steel's tensile strength it ideally has to be sp2 bonded (like CNT, graphene or buckminister fullerene) or sp3 bonded (diamond or diamondoid). Amorphous carbon will contribute (particularly if its fibrous) but not to the degree of the above. So its probably best to mix in the CNTs that is pre-prepared to the molten steel. Would anyone have a graph of steel's viscosity vs temperature that they could kindly share? Lower the viscosity the better the distribution.
 
There was found an actual nanotube structure in old damascus steel. I wouldn't advice just to buy the stuff and mix it in a forge, but there sure is a way to temper with a material and enhance the steel. This can be really interesting experiment.
 
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