Nanodiamonds, wrapped in graphite, reduce friction to almost zero

Scientists from the Argonne National Laboratory, examining the conditions under which it is possible to radically reduce the friction between two solid surfaces, придумали use for this combination of graphene and microscopic diamonds. Thus the diamonds are analogue bearing balls, reducing friction to almost zero.

In our world there is always friction. The smooth surface of the eye contains tiny bumps that are clinging to one another, opposing the movement of the contacting objects. The technique for reduce energy loss and prevent wear of moving parts using grease - sometimes fluid, sometimes thick. In particular, the good lubricating properties of the lubricant has a graphite .

In a microcosm in small perfectly smooth surfaces that are in contact with each other, the friction arises from the mutual influence of atoms. For example, the same graphite surface is composed of hills and valleys, is strongly reminiscent of a box for eggs. If you align the two contacting surfaces, they will be free to slide. If you just turn one of them will occur engagement and friction will increase dramatically.

If the two crystal surfaces have different crystal structure, "incompatible" with each other, the friction between them should be very small. This assumption and took a check, researchers led by Aniruddha Sumantu , physicist and PhD.

Scientists have measured the friction force between the graphene and diamond-like carbon. First, the cell represents a flat two-dimensional surface, and therefore demostriruet low friction . The latter material, diamond-like carbon (DLC) is amorphous like carbon, but it has some properties of diamond crystals. It is used as a coating for various instruments and devices. DLC-coating gives properties such as strength, water resistance and reducing friction forces.

In the experiments, it turned out that the force of friction between the two materials is changing unevenly. After examining what is happening, scientists have found that graphene rolled into small rolls that are rolling between the surfaces, sometimes act like balls in the bearings, reducing friction. Then the experimenters occurred to enhance this effect, adding between the surfaces of small diamonds.



The properties of diamond make it possible to obtain very small particles of it, it is almost at the nanoscale. Results of the experiment has encouraged scientists - nanorulonchiki particles of graphene, nanodiamonds turning around, to ensure the sustainability of the bearing effect, and led to the almost complete disappearance of friction. For the first time turned to reach the superskolzheniya between the two materials that were not ideal microscopic surfaces without defects.

Investigating the properties of the phenomenon, scientists have found that high humidity (greater than the relative humidity of 30%), virtually no effect on driving. Apparently, steam, entering between the surfaces, facilitates their mutual attraction. However, this effect will surely get the benefit of the application in microelectronics, aerospace industry and other areas where you can control the environment.

Source: geektimes.ru/post/250484/