Synthesis and study of triboengineering characteristics of a new nanosize ceramic nickel phosphoromolybdate additive to greases

The work is devoted to investigation of the mechanism of secondary surface structures formed at the nanolevel and their study during frictional contact between solids separated by a lubricant film containing nanosize ceramic matter. The results of study of the NiO-P2O5-MoO3 system diagram are presented. The formation of nickel phosphoromolybdate is shown to occur in the system and its structure is studied using the methods of physicochemical analysis. Nickel phosphoromolybdate is introduced into the PUMA lubricant, employed in rail transport to oil rails and wheel flanges in order to retain the lubricating film and improve the tribological characteristics of the wheel-rail contact via realizing adaptability of the friction surfaces. This occurs at the nanolevel as well, where characteristic secondary structures are formed by the friction-induced effect of nanosize additives having mesogenic properties. The addition of nickel phosphoromolybdate stabilizes both the rheological and physicochemical properties of lubricating compositions of the PUMA series and minimizes their destruction. The molecular mechanism of the nickel phosphoromolybdate additive is also discussed in the work. The work was fulfilled within the framework of a systematic investigation of inorganic polymer phosphates used as multifunctional additives to railroad greases.