| Nowadays,with the development of aviation,power transmission and electrified transportation,friction and wear properties of materials under the condition of electric field and electric contact are highly required.Though the metal based self-lubricating materials are widely used under the condition of current-carrying,the problems of the high friction coefficient and severe wear still exist.Therefore,it’s key to search a new lubricant which can perform well in special working conditions.Ionic liquids(ILs)are new kinds of green materials,which are totally consist of anions and cations,and present liquid state at room temperature.They possess a combination of perfect properties,such as low melting point,non-flammability,high chemical stability.Good lubrication and conductivity are another important characteristics,which provide the possibility to use ILs as the lubricant at electric field or electric contact conditions.In this paper,experiment platform of electrical field and current carrying conditions was firstly established.Then,ILs’ invasive test under electric field was conducted to help analyze the effect on its physical state.The influence of electric field strength,normal load and ILs’ structure was studied.For the current carrying condition,the friction and wear behavior as well as power consumption properties of lubrication under ILs were compared with dry friction.The main results are as follows:(1)The friction coefficient of ILs varies obviously under external electric field.When the applied electric field intensity reaches a certain critical value,the friction coefficient increases immediately,and the stronger the electric field is,the more significant effect ILs exhibit.But when the electric field strength cannot reach the critical value,the change of friction coefficient becomes so feeble that can be ignore.In addition,this paper also studied the effect of ionic liquid’s alkyl side chain length on the lubrication property.The result shows that friction coefficient decreases with the augment of the length,and ILs with shorter length showed better response to the same electric field.(2)Compared with dry friction,ionic liquids exhibit perfect lubrication behavior under electric contact condition.At light load situation,arc erosion phenomenon can be well improved by the lubrication of ILs,wear,friction coefficient and contact resistance reduced apparently.But at heavy load,reducing effect on contact resistance is not significant for ILs,which maybe related to good contact state of friction pairs. |
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