The Distribution of Zinc in Low-Friction ZDDP Tribofilm on Iron Oxide

Abstract

To develop a low-friction and low-wear tribo-system for engine components, the authors have been studying the ZDDP tribofilm formed on iron oxide. Tribotests on iron-oxide / steel sliding pairs were performed in PAO with 1 mass% ZDDP. It was confirmed that the friction coefficient was lower in the PAO with ZDDP than that in pure PAO. The distributions of elements on the wear track of the iron oxide were analyzed by EPMA and found that a zinc-containing layer was distributed on almost entire contact surface.

Keywords

• friction
• water-vapor treatment
• iron oxide
• zinc dialkyldithiophosphate
• zddp
• tribofilm