Wear Characteristics Caused by Ti3AlC2 Particles under Impact-Sliding Conditions in Marine Engine

With the marine industry’s demands for carbon reduction and increased reliability, the friction and wear performance of marine engines is becoming increasingly important. MAX phase materials show great potential in marine engine tribopair materials due to their unique microstructure and performance. The typical MAX phase material Ti3AlC2 was combined with MoDTC and added to the lubricant containing ZDDP additive for the tribopair composed of chromium-based ceramic composite coated steel (CKS) piston rings and cast iron cylinder liners under impact-sliding conditions. Compared to Ti3AlC2 alone, the friction coefficient and wear depth of the designed composite additive MoDTC/Ti3AlC2 were reduced by 36.9% and 41.4%, respectively. The worn surface lubricated with the Ti3AlC2/MoDTC composite additive showed fewer scratches with significantly less plastic deformation and clearer honing grooves. The multi-component tribofilm containing FeS, MoS2, MoO3, ZnO, TiO2, Al2O3, unoxidised particles, short-chain phosphates, and some ZnS was present on the worn cylinder liner surface. The synergistic effect of Ti3AlC2, MoDTC and ZDDP additives in the lubricant can isolate the mutual contact, generate a solid tribofilm and reduce the scratching. This can provide some guidance for the development of high-performance lubricant additives under impact-sliding conditions.