A new material called Proteus is billed as just 15 percent the density of steel, but completely resistant to being cut through. That means cyclists around the world may be blessed with truly inviolable locks for the first time ever.
People who want to steal the outdoor furniture from restaurant patios will have to cut the furniture now instead of the cable lock. Most importantly, TV writers will have to work even harder to make it seem easy to get into a locked electrical storage or nuclear facility.
Researchers in Germany and the U.K. have teamed up to make a material they say uses harmony and vibration to thwart any attempts to cut it. “Our architecture derives its extreme hardness from the local resonance between the embedded ceramics in a flexible cellular matrix and the attacking tool, which produces high-frequency vibrations at the interface,” they explain in their paper.
Inspired by naturally occurring examples like grapefruit skin or the mother of pearl lining of seashells, the researchers embedded tiny spheres of alumina ceramic between a layer of aluminum foam at the core and a layer of steel alloy on the outside. The process is tricky:
“Firstly, the aluminum powder is mixed with titanium dihydride (foaming agent) utilizing a rotating impeller to ensure a uniform mixture. After the mixing stage, the powder mixture is consolidated in a compressor and then extruded 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 for between 15 and 20 minutes.”
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SOURCE: Popular Mechanics, Caroline Delbert