Calcium sulphonate and its interactions with ZDDP on both aluminium–silicon and model silicon surfaces

The boundary lubrication of an aluminium–silicon cylinder liner operating under mild wear conditions has been investigated. The interface was lubricated with synthetic six centistokes poly alpha olefin base oil, which contained either calcium sulphonate or calcium sulphonate and zinc dialkyldithiophosphate. Effective replication of silicon grains within an aluminium–silicon alloy using a silicon crystal substrate affords valuable reproduction of tribofilms. The physical and chemical characteristics of films generated on either substrate were comparable. A marked difference in structure was exhibited between the tribofilms formed from either lubricant. Detailed tribological and tribochemical analysis has been conducted on either substrate.

► Overbased calcium sulphonate tribofilms are generated on silicon surfaces. ► The combination of detergent+ZDDP reduces wear more so than detergent alone. ► Contact conditions on silicon grains are replicated effectively using silicon crystal.