The anti-wear efficiency of boron succinimide on engine cylinder liner and piston ring surfaces

Abstract

Anti-wear additives are important components of the lubricating oils which protect the sliding surfaces from wear. Researches on developing the non-phosphorus catalysis-friendly anti-wear additive still continue due to government’s regulations. One way to provide non-phosphorus anti-wear additive is boron and sulfur addition to succinimides. In this study, boron succinimide used as an anti-wear additive is compared with ZDDPs in a real engine environment by the engine bench tests. Anti-wear performances were evaluated by microscopic and spectroscopic surface analyses on engine cylinder liner and piston rings after 100-h engine running periods for each anti-wear additive. SEM/EDX and XPS analyses were used to evaluate the tribochemical analyses of tribofilms. SEM and AFM were used to evaluate wear mechanisms on cylinder liner and piston ring surfaces. Results showed that boron succinimide can be an alternative anti-wear additive of ZDDPs from the perspective of anti-wear efficiency.