The new cermet material is 6 times lighter than steel, but cannot be mechanically cut or drilled.
To create a composite called Proteus, the team used aluminum foam (73% porosity) and ceramic spheres with a diameter of about 13 mm, regularly and evenly distributed in the foam metal. To increase the strength, the sintered panel was sandwiched between two 2 mm thick steel plates. Steel coated cylinder was also made.
During testing, the drills and disc of angle grinders easily passed the top sheet, but could not advance beyond the embedded ceramic spheres, which began to crumble and blunt the sharp edges of the tool. In this case, the faster the drill or grinding disc rotated, the more the material resisted and the teeth were destroyed..
According to developers from Durham University and the Fraunhofer Institute, this effect is due to the fact that upon reaching the ceramic spheres, the material begins to vibrate, and the ceramics decays into small particles, which fill the voids of the foam metal matrix, complicating their passage. As a result, the force and energy of the drill or disk returns to themselves, so they begin to destroy themselves..
This Material Is Nearly Uncuttable
The team compares the principle of the new material to a sharp jelly filled with nuggets or a sandbag that stops a bullet at high speed..
Tests have also shown that such a structure is no less effective in protecting cermets from waterjet cutting, since the embedded spheres expand the water jet, increasing the impact area, thereby relieving pressure.
Researchers believe that the material can find widespread use in space and military fields, as well as create more advanced armor and locks..
In addition to inventing new materials, scientists also improve existing ones. We recently reported on the development of a carbon nanostructure that outperforms diamond in terms of strength..
text: Ilya Bauer, photo and video: Durham University