Study On Mechanism Of Electron In Tribological Properties Of Graphene Embedded Carbon Film

In recent years,new nano-surface materials have become a hot topic of research.Today,with the rapid development of nanoscience,the traditional tribology,which is applicable to the phenomenon of macroscopic friction,has gradually exposed limitations.People urgently need new theoretical breakthroughs to guide the regulation of friction performance at the nanoscale.In the previous research on graphene embedded carbon film,its tribological properties show a very broad space for exploration.However,the effect of electrons on the friction properties of carbon films has been ignored.In addition,the effect of quantum effects on the tribological properties of graphene embedded carbon films is not clear.Regarding this situation,this paper will study the mechanism of electrons in the tribological properties of graphene embedded carbon films from two aspects: friction and structural characterization experiments and first-principles calculation of quantum friction.In the experimental aspect,the graphene embedded nano-carbon film prepared by ECR(Electron Cyclotron Resonance)was used as a sample.Through advanced experiments and characterization methods such as high-resolution transmission electron microscopy,Raman spectroscopy and friction curve,the electron pair was developed.The effect of carbon film nanostructure and friction properties.In terms of theoretical calculation,in order to explain the effect of quantum effect on the tribological properties of nano-surface materials,this paper will conduct a first-principles computer simulation experiment to study the electron transfer and the change of friction properties under the nanoindentation of multilayer graphene.The specific research results of this thesis are summarized as follows:(1)The nano-carbon film prepared by closed electron irradiation in ECR is subjected to direct current treatment,and the current of 0A,1A,3A is applied to the three carbon films of the same preparation parameter for a period of time.The surface morphology was characterized by a step meter and the friction performance was characterized in a ball-disk friction and wear test machine.The results show that the low-energy electrons in the direct current can promote the low friction coefficient of the nano-carbon film during the friction stabilization period.Through high-resolution projection electron microscopy and Raman peak-to-digital ID/IG analysis of three carbon film samples,it was found that the nanocrystalline structure of the carbon film increased and the nanocrystal size increased with the increase of the current.(2)The first-principles calculation was carried out by using DFTB(density functional tight-binding approximation),and the calculation model was a nano-indentation system of 4-layer graphene under diamond probe.The experimental results show that in the process of indentation,electrons tend to transfer to the surface indentation,and the Coulomb force generated by the charge accumulation on the contact surface leads to a decrease in friction.In the indentation system,as the depth of retraction increases,the hardness of the multilayer graphene increases.Theoretical derivation shows that this is caused by the charge polarization of the graphene surface,the change of the effective contact area and the formation of the crosslinked structure.When the crosslinked structure is formed between the graphene layers,the carbon atoms are transformed by the sp2 bond.The process for the sp3 key.