Study On The Micro Tribological Behavior Of Graphene Additives On The Surface Of Monocrystalline Silicon

Silicon have been widely used in photoelectric devices and micro/nano devices in recent years due to its excellent characteristics,but the problems of friction,wear,adhesion in many applications of it have gradually attracted people's attention.To reduce the friction and wear of silicon surface,graphene and graphene oxide were used as additives to conduct the micro tribological behavior experiments on the surface of monocrystalline silicon in this paper.Combined with molecular dynamics analysis,the anti-wear and lubrication effect of graphene additives on the surface of monocrystalline silicon were studied.UMT-2 micro tribometer was selected for the friction and wear experiment,based on the experimental study of the micro tribological behavior of graphene additives on the surface of monocrystalline silicon.The circular single crystal silicon upper specimen with a diameter of 3 mm and the rectangular single crystal silicon lower specimen with a diameter of 15 ? 10 mm were designed,based on the relevant specifications of the tribometer.The micro texture of the upper specimen was processed by DRIE method.According to the characteristics of lubricating fluid and the wettability of monocrystalline silicon surface,dimethyl silicone oil was selected as the base fluid of the experiment,and the relevant experimental materials and equipment were selected.The shear behavior of graphene and graphene oxide on the surface of monocrystalline silicon was studied,based on the method of molecular dynamics simulation.The adsorption of lubricant molecules on the surface of monocrystalline silicon was discussed.The lubrication of graphene and graphene oxide on the surface of monocrystalline silicon was analyzed.The effects of temperature and pressure on the lubrication of graphene additives on the surface of monocrystalline silicon were discussed.The results show that graphene and graphene oxide have strong adsorption on the surface of monocrystalline silicon and reduced the shear stress of the lubrication system.In a certain range,when the temperature is 298 K,the shear stress of the lubrication system is the lowest;with the increase of pressure,the shear stress of the system also increases,and the lubrication performance of the system becomes worse.Graphene and graphene oxide were dispersed in dimethyl silicone oil by ultrasonic dispersion.The micro tribological experiments of graphene and graphene oxide on the surface of monocrystalline silicon was studied were performed with UMT-2 micro tribometer.The friction coefficients of monocrystalline silicon specimens under different mass fractions were measured,and the worn morphology of the specimens was characterized by SEM.Moreover,the lubrication experiments of graphene additives on the surface of monocrystalline silicon were performed with different textures,reciprocating speeds and applied loads,and the friction coefficients under different working conditions were measured.The friction coefficient and the worn surface morphology of the specimens under different mass fraction of additives were discussed,combined with the molecular dynamics analysis results.The effects of different textures,reciprocating speeds and applied loads on the lubrication performance of graphene and graphene oxide as additives were discussed.The results show that graphene and graphene oxide have good anti-wear and lubrication effect on the surface of monocrystalline silicon,and repair the worn surface.Graphene and graphene oxide produce chemical and physical protective films on the surface of monocrystalline silicon,which are less affected by the speed and have strong bearing capacity.With the presence of oxygen-containing group in graphene oxide,there is a stronger adsorption between graphene oxide and the surface of monocrystalline silicon,which further reduces the shear stress in the friction process.This paper contains 56 figures,6 tables,and 98 references.