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So take a creature like a werewolf or a Fallout deathclaw. Either through evolution or genetic engineering has claws with a graphene edge instead of keratin. The claws work like a more organic version of the hacksaw answer. The top part of the claws has a soft tissue center that can produce more graphene to maintain the graphene ribbon, so the claws overall do have some thickness to them. Assuming the claws are long enough, could a creature using its full force of a swipe penetrate steel plate-mail armor?

If it can then lets up the ante...

Can the same claw (but longer) cut through the steel armor of a modern tank?

One of the challenges I see in general for the scenarios is that the animal's body is relatively normal, and so it has a limit of the amount of force it can exert. So even if the claws are strong enough to handle the force needed to pull it off, the paw might not be able to deliver it.

A second challenge I foresee with the tank scenario is that even if the claws could penetrate they could get wedged while attempting to cut through. Would that be the case? If so is there any way to overcome it?

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  • $\begingroup$ You'd be better off with silicon carbide- it is quite tough and very strong. $\endgroup$ – user2617804 Nov 6 '16 at 8:24
  • $\begingroup$ How do you make a knife from aluminium foil? LIkewise, graphene is flat. If yiu stack it up, it’s not graphene, since the whole point of the name is to discuss the single atomic layer of graphite. So do you really understand what you’re asking? $\endgroup$ – JDługosz Nov 6 '16 at 9:37
  • $\begingroup$ @JDługosz I was thinking along the lines of layering it up to give it thickness. $\endgroup$ – Anketam Nov 6 '16 at 11:09
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    $\begingroup$ That would make it graphite, and nothing special. It is coal. $\endgroup$ – JDługosz Nov 6 '16 at 11:21
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    $\begingroup$ @Mołot your answer is still valid about the claws shattering. All I changed was the implementation so that the claws would hopefully match with the question trying to be posed. $\endgroup$ – Anketam Nov 6 '16 at 12:30
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From wikipedia, but their source is sound:

In 2014, researchers from Rice University and the Georgia Institute of Technology have indicated that despite its strength, graphene is also relatively brittle, with a fracture toughness of about 4 MPa√m. This indicates that imperfect graphene is likely to crack in a brittle manner like ceramic materials, as opposed to many metallic materials which tend to have fracture toughnesses in the range of 15–50 MPa√m. Later in 2014, the Rice team announced that graphene showed a greater ability to distribute force from an impact than any known material, ten times that of steel per unit weight. The force was transmitted at 22.2 kilometres per second (13.8 mi/s).

Emphasis mine.

This suggests that that your graphene claws might shatter instead of cutting thorough. Later results seem different and we need to wait for more data.

Also, remember that graphene is basically 2d structure. It can easily bend, and you need some other medium to keep it straight. If you will just stack graphene layers, you would get graphite. Mono-crystal graphite, but still just graphite.

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Graphine isn't what you want, the proper carbon allotrope is diamond.

And looking at the history of weapons, swords with slashing edges were already pretty much obsolete as weapons by the late 1300's as plate armour supplemented mail armour. To crack through the protection, knights and men at arms changed over to smashing weapons like maces, or increasing the lever arms of bladed weapons with pole arms (or in some cases, two handed swords). The other way bladed weapons evolved was to become narrower and stiffer, eventually evolving into the modern rapier, capable of penetrating the gaps in armour where plates articulated for movement.

The other issue which you will run into is the forces being transmitted through the "blade" need to be mitigated. Japanese katanas are good example, being complex 3 dimensional structures with varying hardness to deal with the stresses and forces of combat. This chart shows a few of the methods Japanese smiths came up with to combine a supple back or core with a hard cutting edge:

enter image description here

This could be done by differential tempering, working the steel during forging (folding the blank during the forging process is the best known method) or even laminating different layers of steel together (much like hammer welding small pieces of steel together was done to make early European swords).

The issue with natural diamond or graphine coating is the extreme differentials in material properties between these materials and natural materials like keratin. The two materials will most likely separate under the stress of impact or "clawing" as they react differently to the stresses.

A bear sized creature is more likely to kill an armoured man at arms by swiping at his head through the force of impact on the skull and neck than by any clawing action.

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In general, bear claws are used more for digging than for actual hunting. As a result they don't tend to be the sharpest claws out there. A monomolecular edge is nice, but unless you're also changing the fundamental shape it's not likely to be the proper claw for either job. I do not expect it to tear through either plate mail or tanks.

(Update) I wouldn't be surprised however if, with some sharpening and the right hit, the bear could pierce plate mail. But I think you are really talking about not just piercing, but also tearing for a notable length. That is where I think bear claws are going to fall flat.

If you sharpened a lions claws sufficiently (and artificially), then sure... plate armor seems plausible as something the claws could penetrate. Arrows and head-on swords did, after all. Tanks however are another story. Tank armor is a lot thicker than plate mail - much thicker in fact than a lions claw. So it would have to scratch and scratch and scratch to create successively deeper gouges, which I expect would take so much time as to be impractical. I also think that the claws would probably break off by then, regardless of how sharp they are.

Here's an interesting gallery for your question - claws from many types of animals.

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  • $\begingroup$ Note I was using a bear for size of the creature, it is not actually a bear. I will update the question with better examples of creatures that have body structures more in line with what my mad scientist is up to. $\endgroup$ – Anketam Nov 6 '16 at 11:33
  • $\begingroup$ I have seen barrel made from 2mm thick metal, that brown bear simply ravaged and teared by claws. $\endgroup$ – vodolaz095 Nov 6 '16 at 14:27
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short answer, no, something the size of a bear just won't be able to create the force necessary to penetrate tank armor, no matter what you make the claws out of. Its bones and tendons with give out before the sheet iron. and they will crush and bend the plate mail before they penetrate it. platemail has lots of things sticking out so a bear sized animal would be able to tear it open by pulling pieces off much easier than they could cut through it. even a regular bear could manage that.

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