Improvement of antioxidation and antiwear properties of polyalphaolefin oils

Polyalphaolefin-based lubricating oils were tested on a four-ball tester, and in a stability test, with antiwear and antioxidant additives of different types, along with other (petroleum and alkylbenzene) base oils and additives. Antioxidant additives for PAOs essentially influence their thermo-oxidation stability. It was found that binary inhibitors increased thermo-oxidation stability effectively. In the antiwear tests, the addition of additives to PAOs sharply decreased wear scar diameters. A significant difference was observed in the action of small concentrations of antiwear additives as between PAO, alkylbenzene and mineral oils. Explanations of this behaviour are put forward.