New way to strengthen metals
Researchers at the
University of Wisconsin-Madison have demonstrated that the rules of
metal-bending aren't so hard and fast after all. They have described the
phenomena in the journal Nature Communications.
Normal metals bend because dislocations are able to move, allowing a material to deform without ripping apart every single bond inside its crystal lattice at once.
Strengthening techniques typically restrict the motion of dislocations. So it was quite a shock when researchers discovered that the material samarium cobalt - known as an intermetallic - bent easily, even though its dislocations were locked in place.
Instead, bending samarium cobalt caused narrow bands to form inside the crystal lattice, where molecules assumed a free-form ‘amorphous’ configuration instead of the regular, grid-like structure in the rest of the metal. Those amorphous bands allowed the metal to bend.