ADSORPTION MODEL OF MESOMORPHIC BOUNDARY LUBRICATING LAYER FORMED BY NANOSCALE ADDITIVE IN TRIBOSYSTEM WITH ABRASIVE WEAR

摘要

The article is devoted to the physical and chemical mechanism of mesogenic lubricating layer formation by oil lubricant (OL) with nanotube additives in the presence of polydisperse solid abrasive phase. Due to reduced surface activity of this type of additives, it is difficult to create a necessary concentration of triboactive component on a surface and, as a consequence, to maintain shielding effect of lubricating film at low concentrations of additive. It has been suggested that the presence of abrasive particles (appeared from outside as a result of wear) having a developed surface can transport nano-additive from OL volume to friction surfaces. A mathematical description of the boundary lubrication process based on the Freundlich adsorption model as well as a model of surface wear depending on concentrations of abrasive and nanoscale additive were developed. Model OL with artificial abrasive and "Taunit" nano-additive were tested. A non-monotonic dependence of wear intensity on the concentration ratio of nano-additive and abrasive was established experimentally. The dependence evidence that the abrasive directly affects not only the wear as in monodisperse suspensions but also counteracts the wear by influencing the kinetics of the boundary layer formation.