Mechanism of lubricating action of polyphosphate and heteropolyphosphate additives in tribosystems

The phase diagrams of the Zn(PO3)2–Ca(PO3)2 and Zn(PO3)2–Ni(PO3)2 systems were studied, and the double phosphates CaZn(PO3)4 and NiZn(PO3)4 were allocated. The anions of these compounds are chain polyphosphates with PO4 tetrahedra in the period of identity. The structures and mechanism of the action of these compounds as additives to lubricants were described using quantum-chemical analysis. Improvement of the physicochemical and tribotechnical characteristics of lubricating materials containing these phosphates compared to the traditionally used lubricating materials was confirmed in tribotechnical tests.