This Material Is Nearly Uncuttable

thanks to brilliant for supporting this episode go to brilliant.org scishow to check out their waves and light course [Music] in comic books heroes are often equipped with practically indestructible materials like adamantium or vibranium unfortunately as anyone who's ever had a bike lock snipped with bolt cutters can tell you we have not figured out how to make something that tough but we're getting pretty close because european researchers claim to have developed a composite material that is basically uncuttable composites are made up of two or more distinct materials that usually have different properties and therefore end up working better together it's like the captain planet of material science concrete for instance is made up of cement rocks and sand when their powers combine they form a strong durable building material the new composite the research has developed is a unique mixture of aluminum steel alloy titanium and ceramic and even though it's six times less dense than steel it's incredibly difficult to cut through here is how they made it first the researchers mixed powdered aluminum with titanium dihydride which was used as a foaming agent the foaming agent's job is to create tiny pockets within the aluminum by releasing gas when heated in this case hydrogen gas then they compressed this aluminum mixture into rods the rods were stacked in alternating rows with ceramic spheres that were about 13 millimeters in diameter and then those rows were laid one on top of another creating a checkered board pattern if you looked at it sideways and all this was then heated to 760 degrees celsius this caused the aluminum to melt and the titanium dihydride to release all that hydrogen gas those bubbles made the aluminum expand out around the ceramic balls once everything cooled the researchers were left with their new composite ceramic balls encased in what is essentially an aluminum foam matrix the researchers decided to name the composite they called it proteus from the shape-shifting greek god from mythology and now all they had to do was test it first they took four centimeter thick plates of proteus and tried to cut through them using an angle grinder and spoiler alert the blades didn't get far the angle grinder disc became unusable in just over a minute after it had made its way through a mere one-fifth of the material yeah proteus is is that tough and according to the researchers that designed it there's two main reasons for that right off the bat the rotating discs started breaking off tiny sand-sized particles of the hardened aluminum foam and ceramic spheres this is exactly what the researchers wanted to happen because small particles have high amounts of fracture toughness which is just a fancy way of saying that small particles are harder to break into pieces and that meant the particles ended up behaving like a rough sandpaper helping wear down the cutting disc small particles are also harder to penetrate as long as the penetrating load or force is applied quickly that's because when there's a large load applied to small particles over a short amount of time the particles squeeze together and become more compact that increases the friction between them and that friction helps them grip on to one another increasing their resistance to being pierced this for example is why bags of sand can stop bullets so proteus's tiny particles resisted the grinder disc while wearing it down then as soon as the blade really hit proteus's ceramic spheres it was game over thanks to vibrations vibrations are the back and forth movement of particles and over time one vibrating particle can cause others to vibrate creating a ripple effect throughout the material when an angle grinder disc starts spinning it generates vibrational waves that radiate out from the center of the disc in this case as the angle grinder made contact with proteus those waves started passing into the material which caused the ceramic spheres to begin vibrating too and so once the vibrating disc came into contact with one of those vibrating spheres that sphere applied a point load to the disk a force that is concentrated in one specific place in this case that point load was applied right on the edge of the grinder's cutting disk and that sent vibrations back into the disk itself that's just newton's third law of motion and action and the researchers believe these forward and backward vibrational waves really dulled the blade see if the vibrations going back into the cutting disc matched the frequency of the vibrations coming from it then the size of the blade's vibrations could have gotten larger due to resonance and if that happened then all that wiggling of the blade could have further ground down the edge of the disc more research just needed to conclusively show that this is what's happening though one way or the other the blades could not get more than a centimeter in the researchers also tried a power drill and a water jet cutter with similar results as long as the cutting implement hit a ceramic sphere it was stopped in its tracks but to make proteus even tougher the team tried tossing in some short nichrome wires these helped improve the tensile strength of the aluminum its ability to withstand being stretched or pulled and once they did that nothing made it more than several millimeters a potentially uncuttable material like proteus is especially exciting for material scientists because there are a lot of ways you can customize it by adjusting the foaminess of the aluminum or the size or number of ceramic spheres the researchers believe they can make proteus adaptable to all kinds of uses bike locks yes but also maybe armored doors or maybe impenetrable shoe soles like black panther so while proteus isn't exactly adamantium or vibranium it could make for a pretty impressive shield thanks for watching this episode of scishow and thanks to today's sponsor brilliant they offer dozens of courses and stem topics including one on waves and light that really shows how those vibrational waves could have torn apart a grinder blade through problem solving and interactive learning you'll learn about interference and how two waves can interact to form really big waves with an annual premium subscription you can get access to that and all of brilliant's other courses so you can brush up on wave physics dive deep into neural networks and learn group theory all for the same low price and if you're one of the first 200 people to sign up for that premium subscription at brilliant.org scishow you'll get 20 off so head on over there if you want to check out what brilliant has to offer [Music] you

Channel: SciShow

Views: 577,738

Rating: 4.942802 out of 5

Keywords: SciShow, science, Hank, Green, education, learn, This Material Is Nearly Uncuttable, material, material science, uncuttable, adamantium, vibranium, Composites, aluminum, steel alloy, titanium, ceramic, dihydride, Proteus, penetrating load, fracture toughness, concrete, point load, resonance, nichrome, wires, strong, strength, bike locks

Id: _6myE3Egrjg

Length: 6min 25sec (385 seconds)

Published: Mon Oct 26 2020

Reddit Comments

[u/Fremenguy]

Also space metal.