The tribological properties and action mechanism of Schiff base as a lubricating oil additive

In this paper, an organic compound containing a nitrogen element, Schiff base, is synthesised, and its tribological characteristics are evaluated by four‐ball and Timken machines. Schiff base possesses friction‐reducing and antiwear properties, especially under low load. Results from X‐ray photoelectron spectroscopy (XPS) reveal that the binding energy of N_1s increases in the boundary film. Differential thermal analyses (DTA) indicate that Schiff base reacts with iron powder, forming complex compounds through hydroxy and azomethine. An action mechanism, with surface‐complex compound films being formed on the surface, is proposed.