Enhanced tribology properties of ZnO/Al2O3 composite nanoparticles as liquid lubricating additives

摘要

Monodispersed and hydrophobic ZnO/Al2O3 composite nanoparticles are prepared by a nonhydrolytic sol-gel method. ZnCl2 and AlCl3 are dissolved in acetone and used as precursors. Oleic acid is adopted as an oxygen donor. The tribology properties of the prepared ZnO/Al2O3 composite nanoparticles are studied by the four-ball friction and thrust ring friction test. It is demonstrated that the average friction coefficient and the wear scar diameter are reduced by 37.5 and 26.2%, respectively, in comparison with pure lubricating oil. Moreover, the ZnO/Al2O3 composite nanoparticles bear the merits of ZnO and Al2O3 when used as lubricant additives, exhibiting both excellent antifriction and antiwear behaviors simultaneously. The ZnO/Al2O3 composite nanoparticles improve the lubrication effect not only by turning the sliding friction into rolling friction, but also forming a hard Al2O3 protective film onto the thrust-ring surface containing ZnO/Al2O3 nanoparticles, which have much potentiality in industrial applications.