Low- friction sliding mechanism and uses thereof

Abstract

A low-friction sliding mechanism includes a pair of sliding members having respective sliding surfaces slidable relative to each other and an ionic liquid applied to the respective sliding surfaces. At least one of the sliding surfaces has a coating of either a diamond-like carbon material, a diamond material or a combination thereof. The ionic liquid consists of cation and anion components and exists in liquid or gel form at room temperature.

1 . A low-friction sliding mechanism, comprising:
 a pair of sliding members having respective sliding surfaces slidable relative to each other, at least one of the sliding surfaces having a coating of either a diamond-like carbon material, a diamond material or a combination thereof; and   an ionic liquid applied to the sliding surfaces, the ionic liquid consisting of cation and anion components and existing in liquid or gel form at room temperature.   
     
     
         2 . The low-friction sliding mechanism according to  claim 1 , wherein the cation component of the ionic liquid is at least one molecular cation selected from the group consisting of imidazolium derivative cations, pyridinium derivative cations, pyrrolidinium derivative cations and ammonium derivative cations and the anion component of the ionic liquid is at least one molecular anion selected from the group consisting of boron tetrafluoride anion, trifluoromethane sulfate anion, hydrogen fluoride anion, hydrogen sulfate anion and dihydrogen phophate ion. 
     
     
         3 . The low-friction sliding mechanism according to  claim 1 , wherein a polar material is added to the ionic liquid. 
     
     
         4 . The low-friction sliding mechanism according to  claim 1 , wherein the diamond-like carbon material and the diamond material have a sp3/sp2 carbon ratio of 2 or greater. 
     
     
         5 . The low-friction sliding mechanism according to  claim 1 , wherein the diamond-like carbon material has a hydrogen content of 3 atomic % or lower. 
     
     
         6 . The low-friction sliding mechanism according to  claim 1 , wherein the diamond material has a nanocrystalline structure with a crystal grain size of 20 nm or smaller. 
     
     
         7 . The low-friction sliding mechanism according to  claim 1 , wherein the coating has an arithmetic mean surface roughness Ra of 0.02 μm or lower. 
     
     
         8 . The low-friction sliding mechanism according to  claim 1 , wherein the coating has a negative surface skewness Rsk. 
     
     
         9 . An automotive internal combustion engine utilizing the low-friction sliding mechanism according to  claim 1 . 
     
     
         10 . An automotive transmission utilizing the low-friction sliding mechanism according to  claim 1 .