Engineers claim to have created the first manufactured material that can’t be cut because it turns the force of a cutting tool back onto itself.
That sounds a bit like an advanced martial art – and the material is named Proteus after the shape-changing mythical god – but it’s actually inspired, they say, by the tough cellular skin of the grapefruit and the fracture resistant shells of molluscs.
In the lightweight material, ceramic spheres are encased in a cellular aluminium structure, which in tests could not be cut by angle grinders, drills or high-pressure water jets.
The idea was developed by an international team led by Durham University, UK, and Fraunhofer Institute for Machine Tools and Forming Technology IWU in Germany.
And it works, they write in a paper in the journal Scientific Reports, because of a dynamic response that is more akin to living structures: the material’s evolving internal structure creates high-speed motion where it interacts with the cutting tools.
The interaction between the disc and ceramic sphere creates an interlocking, vibrational connection that resists the cutting tool indefinitely. The blade is gradually eroded, and eventually rendered ineffective as the force and energy of the disc or the drill is turned back on itself, and it is weakened and destroyed by its own attack.
In addition, the ceramics fragment into fine particles, which fill the cellular structure of the material and harden as the speed of the cutting tool is increased due to interatomic forces between the ceramic grains.
Water jets are ineffective because the curved surfaces of the ceramic spheres widen the jet, which substantially reduces its speed and weakens its cutting capacity.
“Essentially cutting our material is like cutting through a jelly-filled with nuggets,” says Durham’s Stefan Szyniszewski, the lead author. “If you get through the jelly you hit the nuggets and the material will vibrate in such a way that it destroys the cutting disc or drill bit.
“The ceramics embedded in this flexible material are also made of very fine particles which stiffen and resist the angle grinder or drill when you’re cutting at speed in the same way that a sandbag would resist and stop a bullet at high speed.”
And their inspiration? “We were intrigued by how the cellular structure of the grapefruit and the tiled structure of mollusc shells can prevent damage to the fruit or the creatures inside, despite being made of relatively weak organic building blocks.
“These natural structures informed the working principle of our metallic-ceramic material, which is based on dynamic interaction with the applied load, in contrast to passive resistance.”
You only have integrity once. - imprezaguy02
Posts: 12891 | Location: Madison, MS | Registered: December 10, 2007
They’re on their way to something pretty awesome. Now if they can get it thin enough to be worn in a glove...
quote:
Originally posted by sigmonkey: I'd fly to Turks and Caicos with live ammo falling out of my pockets before getting within spitting distance of NJ with a firearm.
It has been discussed on one of the professional forums I belong to.
The safe industry has a long history of using materials that are extremely difficult to breech for the tools and techniques used at the time they were invented. Sooner or later somebody figures out how to go about it.
I had an instructor in college that told us there was nothing (at that time) that couldn’t be cut (torched) in the presence of pure oxygen. This was primarily in context of metals, but I don’t recall him qualifying his remarks.
Give me a couple of milliseconds. I'll get it cut.
________________________________________
-- Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past me I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain. --
Posts: 17783 | Location: New Mexico | Registered: October 14, 2005
Originally posted by RogueJSK: Cool. So then the question becomes: How do you cut/machine it, in order to manufacture it into usable products? Lasers? Plasma?
It's a composite.
Aluminum foam, ceramic beads stirred in, steel plates spot welded over it, I believe.
They would just extrude the foam and ceramic to shape.
Posts: 13068 | Location: Orange County, California | Registered: May 19, 2002
Looks like it's supposed to be formed into shape and finished in a furnace, rather than cut/machined afterwards.
quote:
Manufacturing of the material Our material consists of metallic and ceramic ingredients and consequently requires metallurgical processes to manufacture the end parts.
Firstly, the aluminum powder is mixed with titanium dihydride, TiH2 (foaming agent) utilizing a rotating impeller to ensure a uniform mixture (Fig. 2).
After the mixing stage, the powder mixture is consolidated via cold compaction in a compressor and then extruded through an extrusion die resulting in dense rods of material, which are cut into smaller pieces.
Next, ceramic spheres and compressed aluminum powder rods are stacked in an orthogonal, grillage pattern and enclosed in a steel box using spot welds.
The structure is then heated in a furnace to ca. 760 °C (depending on the melting range of the used aluminum alloy) for between 15 and 20 minutes. The titanium dihydride begins to decompose at approximately 470 °C, releasing hydrogen gas. The release of the high-pressure hydrogen expands the molten aluminum, creating voids.
The components are subsequently cooled in calm air to produce a stable cellular structure with embedded ceramic components.
Posts: 15235 | Location: North Carolina | Registered: October 15, 2007
"The people hate the lizards and the lizards rule the people." "Odd," said Arthur, "I thought you said it was a democracy." "I did," said Ford, "it is." "So," said Arthur, hoping he wasn't sounding ridiculously obtuse, "why don't the people get rid of the lizards?" "It honestly doesn't occur to them. They've all got the vote, so they all pretty much assume that the government they've voted in more or less approximates the government they want." "You mean they actually vote for the lizards." "Oh yes," said Ford with a shrug, "of course." "But," said Arthur, going for the big one again, "why?" "Because if they didn't vote for a lizard, then the wrong lizard might get in."
Posts: 3612 | Location: Two blocks from the Center of the Universe | Registered: December 30, 2004
Originally posted by asonie: I bet my dog could wreck it. She’s the most destructive force in the universe.
_________________________ NRA Endowment Member _________________________ "Of all tyrannies, a tyranny exercised for the good of its victims may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the approval of their own conscience." -- C.S. Lewis
Posts: 5701 | Location: District 12 | Registered: June 16, 2012
