Polymer-like amorphous carbon is a kind of hydrogen-containing diamond film, which is amorphous and has compounds similar to polymers, and is formed by repeatedly connecting the same simple structural units through valence bonds. This kind of diamond-like carbon film is soft because of the large number of sp2 bonds, and it does not have the characteristics of graphite, which limits its application and is still in its infancy in tribology.
Diamond-like carbon film (DLC film) is an amorphous carbon film with diamond-like structure, which really needs to be introduced here. The basic component of DLC film is carbon. Due to different carbon sources and preparation methods, DLC films can be divided into two categories: hydrogen-containing and hydrogen-free. DLC film is a metastable amorphous material with long-range disorder. The bonding mode between carbon atoms is * * * valence bond, which mainly includes sp2 and sp3 hybrid bonds. There are also a certain number of C-H bonds in hydrogen-containing DLC films. Starting from 1996, we started the research on magnetic filtering vacuum arc and depositing DLC film, and are perfecting the industrialization technology. Such as plasma source deposition, ion beam source deposition, double intermediate frequency magnetron sputtering, vacuum cathode arc deposition and pulsed high voltage discharge. The composition, structure and properties of DLC films obtained by different preparation methods are different.
Diamond-like carbon film (DLC film for short), as a new type of hard film material, has a series of excellent properties, such as high hardness, high wear resistance, high thermal conductivity, high resistivity, good optical transparency and chemical inertia. , can be widely used in machinery, electronics, optics, heat, acoustics, medicine and other fields, and has a good application prospect. We developed a plasma-ion beam source enhanced deposition system, and in this system, DLC films were prepared by magnetic filtration vacuum cathode arc and unbalanced magnetron sputtering.
This technology is widely used in electronics, decoration, aerospace, machinery, information and other fields for friction and optical functions. At present, China's technology is in the stage of development and perfection, and its market potential is huge.
Graphite-like carbon is the last kind of diamond-like carbon containing hydrogen, which has similar characteristics to graphite, and the content of sp2 is about 70%. In modern times, diamond-like carbon films have attracted wide attention because of their high hardness and low friction coefficient. However, there is a "catalytic effect" between diamond-like carbon film and iron-based materials commonly used in industry, that is, the high-hardness sand bond of electroplating tools will be converted into soft bond protection during the processing of ferrous metals, which will sharply reduce the wear resistance, thus limiting its application scope. Liu Xianghuai and others used ion beam assisted deposition technology to prepare graphitized films meeting the requirements of electromagnetic function, and proposed that there was a "carbon structure" with high hardness. Later, Britain and the company prepared a patent for fully enclosed unbalanced magnetron sputtering high hardness carbon film. Reading research shows that one is mainly composed of sand structure, which has no "catalyst effect" when rubbing against steel materials, moderate hardness, small friction coefficient and one order of magnitude lower than the wear rate. The structure and properties of carbon films with excellent tribological properties are largely related to their preparation process. This method is convenient to control the auxiliary bombardment parameters to change the coating structure, and the deposition rate of magnetron sputtering is high, so that thicker coatings can be prepared. This carbon film is neither ordinary graphite nor graphite, so it is temporarily called graphite-like carbon film.