Watch this metal foam turn an armor-piercing bullet into dust

midian182

Posts: 6,672   +59
Staff member

While Kevlar is often used to protect law enforcement and soldiers from projectiles, it struggles to stop armor-piercing bullets. But now a type of composite metal foam (CMF) has been developed that can annihilate this type of ammunition on impact.

Created by Afsaneh Rabiei, a professor of mechanical and aerospace engineering at North Carolina State University, the inch-thick foam is able to absorb so much of a 7.62 x 63mm M2 armor-piercing bullet’s impact, it leaves an indentation on the back measuring less than 8 millimeters. For context, the National Institute of Justice standard allows up to 44 millimeters indentation in the back of a piece of armor.

As you can see in the video, the bullet shatters when it hits the foam. Rabiei also tested it against the standard NATO 7.62 × 51mm rounds. The material could be used in future versions of body armor, providing lighter and safer protection for armed forces personnel and police. It could even be applied to vehicles.

CMF is created by incorporating hollow beads of one metal into a substrate cast from another. In addition to stopping armor-piercing bullets, it resists heat and fire much better than the metals it’s made of. It’s also shown to be remarkably effective at blocking X-rays, gamma rays, and neutron radiation. These properties mean it could have applications for nuclear material transportation/storage and space travel.

While CMFs have been around for decades, the true potential of the material is only now being fully realized.

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madboyv1

Posts: 1,672   +580
I wonder how well this might work in the transportation industry, specifically cars, as it sounds like it has the potential to both reduce weight and increase strength.
But at what cost? Carbon Fiber also reduces weight and increases strength but it is still a niche material often reserved for luxury and/or sports cars due to it's prohibitive cost and difficulty in being repaired.

Still, very cool stuff, especially it's radiation(read:thermal, gamma,x-ray, and neutron radiation) stopping effects. I wonder how difficult it is to produce as well as it's cost. I could probably look it up but my resources are limited at the moment lol...
 

madboyv1

Posts: 1,672   +580
Now shoot at it from an angle. I want to see what happens then.
Unless this foam has non uniform structural strength (like carbon fiber sometimes does), would it not offer more protection since the increased width of material when coming from an angle? Or are you thinking it's like concrete where it has great compression strength but get it at the right angle and thickness (and lack of internal support) and it fractures without much effort?
 

Uncle Al

Posts: 8,001   +6,775
Now shoot at it from an angle. I want to see what happens then.

7.62 NATO round is the snipers choice of ammo because of the knock down power and much lighter weight than the standard .50 cal round. While a dead on shot is every snipers preference, it's certainly not always the case and I would also like to see the performance in hot and cold environments as well. Certainly wonderful if it works, but I am not yet convinced. Also wondering how may layers would effectively stop a .50 cal?
 

wiyosaya

Posts: 5,786   +3,994
Now shoot at it from an angle. I want to see what happens then.
Unless this foam has non uniform structural strength (like carbon fiber sometimes does), would it not offer more protection since the increased width of material when coming from an angle? Or are you thinking it's like concrete where it has great compression strength but get it at the right angle and thickness (and lack of internal support) and it fractures without much effort?
My bet is that the material is uniform in all directions - or at least that is probably what they are trying to achieve through the use of foam. If hit at an angle, then, what happens would probably depend on the shape of the round. A conical round coming from an angle might just "bounce off" as the round is designed to hit on its point (I.e., so the tip of the point is orthogonal to the surface of its target) - which is where the maximum force would be.
I wonder how well this might work in the transportation industry, specifically cars, as it sounds like it has the potential to both reduce weight and increase strength.
But at what cost? Carbon Fiber also reduces weight and increases strength but it is still a niche material often reserved for luxury and/or sports cars due to it's prohibitive cost and difficulty in being repaired.

Still, very cool stuff, especially it's radiation(read:thermal, gamma,x-ray, and neutron radiation) stopping effects. I wonder how difficult it is to produce as well as it's cost. I could probably look it up but my resources are limited at the moment lol...
Cost is certainly a valid consideration. Carbon fiber, though, only achieves it maximum potential if it is used as part of a sandwich structure. Straight carbon fiber reinforced by epoxy, while very light, would not be very impact resistant.

Usually, however, if enough of a material is produced and used in products, it becomes much cheaper.
 

captaincranky

Posts: 16,520   +5,320
Also wondering how may layers would effectively stop a .50 cal?

I'm going to hazard an admittedly amateurish guess:
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jonny702

Posts: 35   +11
Now shoot at it from an angle. I want to see what happens then.

7.62 NATO round is the snipers choice of ammo because of the knock down power and much lighter weight than the standard .50 cal round. While a dead on shot is every snipers preference, it's certainly not always the case and I would also like to see the performance in hot and cold environments as well. Certainly wonderful if it works, but I am not yet convinced. Also wondering how may layers would effectively stop a .50 cal?
. 338 Lupua Magnum is becoming increasingly more popular. I'd love to see how it stands against that
 

cliffordcooley

Posts: 12,696   +6,055
I'm not a gun or ammunition enthusiast so I don't know the differences between bullet calibers. I do know a projectile will ricochet. I'm wondering at what angle it will no longer disintegrate.
 

captaincranky

Posts: 16,520   +5,320
I'm not a gun or ammunition enthusiast so I don't know the differences between bullet calibers. I do know a projectile will ricochet. I'm wondering at what angle it will no longer disintegrate.
You know how it pains me to say something as callous and uncaring at this but ;), if the bullet ricochets off you and kills the person next to you, so what? :p:cool:
 

ikesmasher

Posts: 3,100   +1,492
This was strangely mesmerizing to watch. and its got some pretty cool implications.

Funny to attend to attend NCSU and not hear anything about this till I see it on techspot.
 

RebelFlag

Posts: 172   +102
I am interested to see how well this will work as body armor, as it does not seem to have much flexibility. Might be better suited to being used as vehicle armor instead.