What is Metal Foam and Why Does it Work? | Sci NC

Metal foam takes its cue from bubble wrap, absorbing the energy of an impact by changing the shape of the bubble. However this composite composite foam developed at NCSU is super strong, offering new protection to military members, by blocking blast pressure and fragmentation at close range.

[@jamal69jackson77]

I wish I could test this material for body armor applications. I know that they've conducted their tests at the university but an independent test would be helpful in validating data. Not to mention understanding the limitations of the material by taking it to its limits and observing everything from back deformation, compression, level of penetration, energy transfer, maximum amount of impact resistance to various specific threats both spread out and focused, as well as its behavior in extreme heat, extreme cold, wet conditions and ultimately the causes or stresses that lead this material to failure under every condition. Perhaps this material could be used in conjunction with kevlar, UHDPE or other armor materials to achieve an ideal weight ratio and resistance level. I wish I knew more, I'm intrigued.

[@Arukorstza]

A plate less than one inch thick has enough resistance to turn a .30-06 Springfield standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with many times the resistance to fire and heat as the plain metals. Another study testing CMF's resistance to .50 caliber rounds found that CMF could stop such rounds at less than half the weight of rolled homogeneous armor. Straight fort he wiki entry for metal foam.

[@jamal69jackson77]

@@Arukorstza I really wish I could test it still or even better, manufacture it, but I don't have a lab or the knowledge to do so. I wonder when and if it will be adopted into use for whatever purposes it can serve.

[@TN-br9yl]

Sacrificing strength for impact absorption. Cool!

[@P-tricky13]

Cool!

[@edbouhl3100]

I’d love to have it as house siding and roofing. Fireproof, bullet resistant, light, probably high wind resistant, and no painting required! Wonder if it has any insulating value (R-value) or heat reflectance? Or EMP shielding potential (your house as faraday cage). It also probably has some uses in seismic resistance.

[@thomaseubank1503]

Sign me up

[@alexanderday7264]

Good luck getting any phone signal though

[@wok3051]

Idk if it would have insulating value as it is a metal so probably a better conductor

[@stevetennispro]

@@wok3051 It is metal, but with bubbles. So yes, very good insulation. They used a blow torch on it in another video and it offered incredible insulation from the heat.

[@benyaminlatifian3115]

Mersi khanom doktor

[@asku6926]

Very cool

[@lutherheath8997]

No round, API or otherwise, has a muzzle velocity of 5,000 ft/s, with the exception of saboted 120mm tank rounds. The M2AP round only has a muzzle velocity of 2740 ft/s.

[@xarthurmasterz]

This must be every trypophobiac's nightmare.

[@secondary2nd]

I don’t believe trypophobia exist, or at least majority of them are just snow-flaking

[@samhenley7156]

I came up with something similar about a year ago before I learned about this. This is better though.

[@Locrian08]

Does anyone know if this can be done with cheap, low melting point (cerro) metal alloys and foaming agents? If so, and if it could be diy or cheaply mass produced, it could be great for storm shelters.

[@dcappucino9513]

It’s all fun and games until someone hits you with an electric bolt

[@noarhaxhiu9126]

Would this work the same if it was cut in half?

[@trevorgwelch7412]

How much does 1 square foot cost 1 " thick ???

[@kanpurunplugged9970]

there is a clause for uniformity of lattice for such a material

[@epsospremium6088]

Let's *make space ships* from this material. Asteroids like to bump into spacecraft.

[@DrReginaldFinleySr]

Primitive shields.

[@JonDeth]

I get it, the metal foam deforms absorbing enough energy in an instant to be able to shatter the projectile that instantly lost the velocity to penetrate upon the first few mm of the object's impact. So just like other foams, it returns back to it's original shape. *All be it granted enough hits and like other foams, it will be breaking down.*

[@ZebbMassiv]

How well does it float?

[@VincentGonzalezVeg]

Occlusions of air that weigh less that what the material weigh Like bubble wrap, there's also internal airpressure

[@lilj3467]

I don't think he's talking about floating in air.. rather on the water. I think he's inquiring as to the ability of this material to perform as a material used in a water-craft.

[@RagexPrince683]

how to make?

[@priyansuchoudhury0246]

All the comments are like this is something new.

[@lutherheath8997]

Also, this video neglects to mention what is found in her paper, i.e. that the actual armor was an ultrahard ceramic that was merely backed by the metal foam.

[@MikeTrieu]

That's similar to how most bullet-resistant glass is constructed: hard tempered glass laminated to softer, energy-absorbing polycarbonate sheets. You really need a hybrid of both hard and compliant materials to be an effective kinetic shield.

[@Seth9809]

Actually no, it was metal foam that had a thin layer of ultra-hard ceramic in front and an aluminum backing. Most vehicle armor uses ceramic anyways, but this still manages to save a lot of weight.

[@Zarrar2802]

Hi, would you happen to have the research paper? I have tried on the internet but all these websites want me to pay 35 dollars for a single research paper :/

[@MrCrimson31]

Was it a boron carbide ceramic tile?

[@riesenfliegefly7139]

Ballistic numbers please. A ceramic/polyethelene plate from safe life defense can stop 308 AP rounds at 18mm thickness and 3,5kg per 1000cm^2. Can it top that ? :D

[@jackmclane1826]

Absolutely not. It's been a research hype since my father was at university. He graduated on this topic in the 70ies. They were making around with that stuff and found some nice uncommon combination of properties but in the end you could find better selutions for almost all possible niche applications.

[@riesenfliegefly7139]

@@jackmclane1826 Yeah, thats what I think as well :D

[@HK52]

Hey somebody tell me please, can stop bullets??

[@non-foldingchair270]

Basically they make high temperature refractory air balls and mix it with molten titanium and this what you get.

[@themetalgamer9864]

I want a suit of armor made out of this.

[@commanderfoxtrot]

Coming right up, just give us time, unless you’re willing to move here and help aid the projects.

[@PhysicsViolator]

i want a suit made of this stuff

[@madarauchiha8621]

Like Mandalorian armor

[@commanderfoxtrot]

@@madarauchiha8621 what about big, bulky armour mounted on an exoskeleton, that you can customize the aesthetics of to match whatever you want? We’re looking for aid on our project, if you’re willing to commit.

[@ballapeti]

She’s just got immensely rich.

[@aethelyfel7573]

Not yet, whoever can reduce the cost of manufacturing and manufacturie in mass will make the big bank.

[@diyartokmurzin7640]

I wonder, what if aluminosilicate microspheres from coal combustion power plants are used for creating the bubbles inside the metal? 🤔

[@richardheisler3375]

Ok it works well but how does it handle 2 or 3 shots in the same exact spot because steal plates are way to heavy the newer poly blend stuff is amazing but many rounds can still penetrate it if her armor can take several rounds right on top of each other awesome but what's the cost

[@tedantares2751]

The most obvious application of this technology it armor - first of all, body armor and armor for military planes.

[@PhysicsViolator]

So all I need is molten stainless steel and apply bubbling air in it and walla?

[@JPalermo]

Molten steel and a straw to blow bubbles in it. Just don't suck in

[@Zarrar2802]

Aint so simple, you need to get steel spheres, arrange them in a lattice, fill the holes with steel powder (maybe?) and then heat the whole thing up until it all melts (and pray you dont melt the steel balls in the process)

[@davidbann8388]

Thats what I was thinking...

[@davidbann8388]

@@Zarrar2802 take hollow spheres of steel and use molten alum to hold it together?

[@Zarrar2802]

@@davidbann8388 nope. The original scientist spent years trying to get the right mix so it would compress to 80% of the size. Only then is it effective at stopping anything. That's the real complex material science behind it. If only I could get my hands on the research paper :(

[@johntheux9238]

We can't see a thing on the slow motion. And it's kind of funny how the guy just ignore her at 3:56 "It's not stronger, but it can absorb more energy" -> "Strong and lightweight" Shut up!

[@Seth9809]

If armor absorbs more energy, it is considered a "stronger" armor, but that doesn't mean it's made of "stronger" materials.

[@johntheux9238]

@@kalmansandor5930 You mean a phantom?

[@johntheux9238]

@@kalmansandor5930 I mean, they just poured aluminium around hollow steel balls. Just ask me and I can do that for 100$ The hollow steel balls might be tricky if you can't buy them...

[@johntheux9238]

@@kalmansandor5930 Would be fun to use high pressure gas filled balls instead of hollow balls. I'm pretty sure there would be some elastic recoil.

[@johntheux9238]

@@kalmansandor5930 Yeah, pressure will increase as the temperature goes up while the steel will soften up. Bubbles might burst...

[@stevenkester8422]

It's my invention.

[@josephreagan9545]

Space... She needs to takes this to space. Someone get this woman talking to Elon Musk

[@cliffcox7643]

I dont think those are "bullets", that she held up. At that point they're called cannon.

[@dcappucino9513]

cliff cox no cannon is bowling ball.

[@Seth9809]

Shells, they are shells.

[@michaeljohn7405]

Did anyone even give. A shout out to this scientist and say her name and name it after her.

[@calicraig8369]

Shouldn't this be Top Secret?

[@operator8014]

It was made by a public University, not a military department or contractor.

[@MrRedsjack]

@@operator8014 China says thank you for the clear explanation to the lady which is very smart in some ways but not very forward looking. Now the USA taxpayer has paid her to develop this material which will be copied in China tomorrow

[@operator8014]

@@MrRedsjack It would be illegal to do this any other way. If the military thought it was worthwhile, they should have tried to buy out the project earlier. ALL scientific findings by publically funded institutions are freely available to the taxpayers. That is by design, we pay for it, we get it. China doesn't care, this stuff isn't that good at anything and it's not really a breakthrough, just a refinement of something that has been well known for 50 years.

[@nickl5658]

Has been around since the 1950s. The real problem is making a large homogeous sheet.

[@kpocalypss3596]

BS. 30 cal ap rounds don't travel at 5000fps... more like 2500 to 2700 fps... once again, bad reporting

[@slashdotism]

It's probably the idiot reporter seeing 5000 fps on the video or the file name of the bullet hitting and thinking it's feet per second instead of indicating that the high-speed recording is filmed at 5000 frames per second which seems to fit the footage.

[@bigbluebuttonman1137]

@@slashdotism Yeah. According to the actual scientific articles, it was able to stop .50 cal rounds at speeds between 500 and 885 meters per second. www.sciencedaily.com/releases/2019/06/190605105943.htm It's still impressive.

[@wildcard5269]

She's Awesome And Hot as she explains the Science behind the metal.

[@tallnrough68]

This is cool, but a hard sale, I don’t see many practical applications for it

[@NwoDispatcher]

armored cars?

[@mattjohns3394]

Just off the top of my head, car bumpers could be made of this stuff to absorb impacts better or some part of an aeroplane could be made lighter. Chances are, it'll find a niche market where it performs outstandingly well against a current technology and be mostly confined to that industry. Or it could be just like carbon nanotubes, no one seems to know what to do with those either.

[@RagexPrince683]

I dOnT sEe MaNy PraCtIcAL ApPLicAtIoNs FoR iT shut up civilian

[@transparentguy9096]

aircraft?

[@bebehasbebehas2287]

Maybe, Musk can use it in his steel rockets?

[@BossSpringsteen69]

He needs to worry about launching safely first.

[@SunTzu2024]

would love to see this used in tank armor if its already is not.

[@dl-xq2su]

1/3 almost a turd! Haha

[@davidbann8388]

NONSENSE! ... made some last night in the kitchen....😁

[@dejandimoski4605]

the first video didn't show no bullet hitting nothing , we only saw fragments of an already shattered bullet hitting something .What kinda BS is this ?!

[@TroubledCarOwner]

This was just very poor reporting. The researcher clearly didn't do his/her homework. That was an experiment of shockwave and shrapnel protection against up to a 23mm HEI round. Often shockwaves from an HEI round can seriously injure occupants inside an armoured vehicle even if no penetration occurred. The experiment had the round hitting a 2.3mm aluminium strike plate. The CMF plates 18 inches behind were only 9.5 to 16.75mm thick (3/8" to about 5/8"), but offered the same level of armour protection against shrapnel to a comparable (in performance, not thickness) steel armour for 1/3rd the weight, but with superior shockwave protection.

[@Zarrar2802]

actually, the first video is not showing bullet impact, it's demonstrating a bomb blast shrapnel impact at 18 inches (i think)

[@BossSpringsteen69]

I'm not convinced.

[@jfobel2204]

Just a fair warning to not buy into the big lie of steel foam. Even in World War II they found when applying any kind of steel material, the more holes you place inside the plate, the more likely it is to ruin the integrity of it, causing a weakening affect of how much direct force it could absorb by itself. So basic logic says punching a bunch of air and holes through a steel block is going to fundamentally reduce the amount of strength it has through something called the 'Over-match' effect. Or when a full caliber round fired from a gun roughly 10 times the millimeter of a plate, it will usually ignore its effective thickness and go right through it. This is how instances such as Panzer VI's Ausf.H1 or E ("Tiger I") guns were able to punch nearly 3 foot diameter holes inside the front of T-34 hulls. Because the metal had too many holes and gaps of where the plate had too many impurities that ruined its integrity to uphold being punched through. The most I see this being used for is small arms at best. Being applied anywhere else it's beyond outclassed.

[@Van-yo2xr]

It’s aluminum not steel. The balls are steel, which similar to bending sheet metal, makes them stronger than an equivalent amount of material.

[@jfobel2204]

@@Van-yo2xr RHAe tables would massively disagree with that statement. While aluminum is noted having a higher chemical resistance to most shells, its kinetic resistance is drastically lower than steel as a base, and steel balls would not solve that problem. Ballistics and strength under pressure are two massively different animals.

[@Van-yo2xr]

@@jfobel2204 can you read?

[@jfobel2204]

@@Van-yo2xr "its aluminum, not steel. The balls are steel." I can, but perhaps your use of contextualization to prove a point just can't portray what you mean. But thank you for resorting already to insults not even two comments into my objection. That only proves how quickly this derailed and we haven't even started.

[@Van-yo2xr]

@@jfobel2204 go lick some imperialist boots. You still can’t understand the syntactic foam has an aluminum substrate.

[@kob8634]

WTF?? That demo makes zero sense. The 'size' of those bullets makes *zero* difference. This is a grift!

[@Micha-xi6sb]

Not a gun expert, but don't bigger calibers have more propellants and higher bullet mass?