It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe friction and wear.Fullerenol,a kind of highly water-soluble nanoparticle,was synthesized and then used to ameliorate the tribological properties of Si 3 N 4 sliding against Al 2 O 3 in pure water.With the addition of fullerenol,the running-in period was shortened from 30 min to 100 s at a speed of 250 mm/s.The speed threshold above which ultralow friction can be obtained in a short time was expanded from 450 mm/s to 80 mm/s.Meanwhile,the load-carrying ability of water film was increased.The role of fullerenol was discussed based on observation of the wear scar by an optical interferometer and XPS characterization of the tribo-film on the wear track.
LIU YuHongWANG XiaoKangLIU PengXiaoZHENG JunPengSHU ChunYingPAN GuoShunLUO JianBin
Superlubricity is a new area in tribology,in which the slide friction coefficient is about 1/1000 to 1/100 of the general ones.Since the concept of superlubricity was proposed,it has attracted more and more attentions from researchers in fields of tribology,physics,chemistry,materials,etc.Many significant progresses have been made during the last two decades in experimental studies on superlubricity.In the present work,the recent advancements in solid superlubricity and liquid superlubricity are reviewed and the lubricating mechanisms of different superlubricity systems are discussed.Finally,the problems on the superlubricity mechanism and the development of superlubricity in the future are addressed.
