Abstract:The lipophilic treatment of the pretreated montmorillonite was conducted by four modifiers,oleamine,oleic acid,KH550 and cetyltrimethylammonium bromide(CTAB).The effect of the amount of dispersant on the dispersion stability of modified montmorillonite in oil was studied.The effect of the dispersion of modified montmorillonite in oil on its tribological properties were was investigated on a four ball friction and wear tester.The results of contact angle and infrared spectroscopy analysis show that CTAB has the best effect on the lipophilic modification of montmorillonite,and the absorbance test results show that when the mass fraction of dispersant is 6%,the modified montmorillonite has the best dispersion effect in oil.The results of friction and wear experiments show that the dispersion of montmorillonite in oil has a great influence on its tribological properties.CTAB modified montmorillonite without dispersant is not stable in the base oil,and its friction coefficient is only 9.27% lower than that of the base oil.While the oil with CTAB modified montmorillonite and dispersant can reduced the friction coefficient and wear scar diameter by 19.21% and 40.29% compared with base oil,respectively.The results of SEM analysis show that in the process of friction,the montmorillonite particles are easy to deposit in the low depression of the worn surface,forming a protective film,which can reduce the damage of the contact surface and play a certain role in repairing,but when the montmorillonite particles are not well dispersed,they are easy to agglomerate,which will increase abrasive wear and reduce the repairing effect