Any armorers/blacksmiths on here?

[Urban Predator]

As far as armor (modern armor, that is) hardening in reaction to an impact to disperse forces, haven't they experimented with rheopectic gels? I seem to recall so. Thixotropic materials, the inverse of (and much commoner than) rheopectic compounds start out gelatinous and when exposed to a shearing force, thin out. Rheopectic materials do the opposite, suddenly hardening when exposed to shock, in the vicinity of the impact. IIRC such materials have been experimented with for armor purposes.

Also, with respect to 'diamond like structure', even if that were the case, a diamond would make rubbish body armor, true, it is extremely hard, but it is also brittle, and a brittle material would simply shatter on impact

 

[Hassknecht]

Also, with respect to 'diamond like structure', even if that were the case, a diamond would make rubbish body armor, true, it is extremely hard, but it is also brittle, and a brittle material would simply shatter on impact

I guess the sp2-hybridization in multilayer graphene could be turned into diamond-like sp3 bonds under impact, but I don't really see the benefit for armor purposes. Armor works in two ways, by dispersing the impact energy over a larger area via immense tensile strength (kevlar fibers) and by using the energy to deform an extremely strong material (steel and ceramic plates). Turning graphene, which has extreme tensile strength, into diamond would probably combine the effects, but sincr graphene is extremely thin I don't think it would actually work. Also, graphene is still quite brittle itself, and it's hard to synthesize on large enough amounts without defects.
I think a carbon nanotube weave of sufficient thickness, density, and quality would work very nice as an ultralight kevlar replacement, though. Graphene by itself, not so much.

 

[Crni Vuk]

Hmmm?

 

[Urban Predator]

I would have thought the sp2>sp3 orbital hybridization change, if it were to take place under impact, assuming one could of course, manufacture sufficient quantities of sufficiently defect-free graphene sheets would probably need significantly higher pressure over a much smaller area than is typical of a bullet.

I agree though that a nanotube weave would be much more practical, certainly within the forseeable. Spider silk might be interesting also. There has been quite a bit of research into obtaining it in quantities more useful than having to deal with large numbers of (cannibalistic, territorial, pissy and hard to work with) spiders, such as splicing the requisite genes into goats, so the milk can be processed to make it.

Nanotubes of course a hollow..I have to wonder if the protein would be too big and bulky in its 3-D folded structure to fit in the core of a carbon nanotube to make a composite material.

Even without, I was just thinking earlier along the lines of a rheopectic matrix hosting a laminated carbon nanotube weave, in order to take advantage of the tensile strength of the nanotubes, to help prevent outright penetration of the rheopectic gel/fluid whilst the latter disperses the shock of impact as much as possible. The rheopectic matrix component, given the way such materials behave, stiffening upon impact and returning to their original state after the force has dissipated, would in effect be self-healing. If its 'ground state' is too fluid, one could even combine it with an outer layer of something air-reactive and fast setting, such as, for example, the liquid precursor form of spider silk, so that upon puncture of an outer metallic shell (who's thinking light-weight powered armor here ) to function as a reservoir, it would flow out, meet the air, solidify and patch over the external entry hole, just like human blood with its platelets, fibrin and clotting factor.

Come to think of it...why not just that...armor that bleeds...that could both inspire terror among enemy troops, with a soldier appearing to take round after round and carry on charging, or for a soldier to feign death, only to get right back up and shoot the enemy in the back.

 

[Gonzalez]

I guess gravedigging is no longer a thing, at least someone is commenting on our site!