Electrons and plasticity of metals

It turns out that electrons affect the mechanical properties of metals. If you pass through an electric current, you can change its strength and ductility. In addition, the transformation of the alloy into a superconducting state caused also a change in its mechanical properties. And superconductivity is closely connected with the motion of free electrons.

This physical phenomenon is called the electronic-plastic effect - EPE. Now scientists know that metals are deformed due to the birth and displacement of so-called dislocations - peculiar mobile defects. This is a kind of folds in the crystal lattice. If an electron wind is formed in the metal, it accelerates the moving dislocations, as a result, the metal becomes more pliable.

It turns out that the main reason for the remarkable properties of the metal is that each atom gives some of its electrons to general use. As a result, a free-electron gas arises that fills the entire crystal lattice and even protrudes somewhat above its surface. This gas can move around the metal in any direction, for this it is sufficient to apply an electric potential to it. It does not remain passive even when the metal is heated or cooled, and also if it is deformed, it is converted into wire, tape or sheet. In all cases, the gas of free electrons acts as a kind of softening medium and does not allow the metal to melt or crack.

Particularly interesting is the ability of electrons to impart plasticity to the metal. Why does the electron gas cause an increase in the plasticity of the metal? After all, plasticity is a crude, purely mechanical property of metal. The secret, it turns out, is the existence of a close organic bond between the electron gas and the atoms in the crystal lattice sites. After leaving individual atoms and merging into a collective, the electrons continue to tinker among the atoms, not allowing them to move away from each other for long distances during deformation or heating of the metal. The electrons instantly appear in those regions of the lattice where a stretched band forms during the plastic deformation, and, conversely, leave the region where a strong compression has arisen. In other words, electron gas reacts quickly to any critical situation in the metal, preventing it from overloading and overheating.

EPE is also of great practical importance, since it allows materialists and practitioners to re-characterize the plasticity of metals and alloys in a new way. There was a possibility to process pressure such metals and alloys, which do not allow large heating during machining. For example, alloys based on tungsten.