Stribeck type liquid metal-based conductively frictional agents

As a pair of contradictories, working efficiency and service life in braking systems depend on the friction performance and wear rate of brake pad, respectively. Extending the service life while maintaining the working efficiency has become a key issue in industrial field. Here, a Stribeck type conductively frictional agent (CFA) of LM@reduced graphene oxide (rGO), composed of liquid metal (LM) and reduced graphene oxide (rGO), is synthesized at room temperature (RT). The structure combines the nano-confined water induced basal alignment, covalent and π–π small plate bridging the interactions. During the friction process, the van der Waals force at the friction interface is converted into the coordination bond between the graphene hydrogen and the LM to enhance the interfacial interaction and friction effect. Moreover, the LM is infiltrated into the tribo-pair surface to assemble layer by layer with the graphene, and the composite structure on the boundary lubrication and fluid lubrication overlapping regions are formed to improve the tribological performance. The coefficient of friction (COF) of LM@rGO CFA coated sample is increased by 525% compared with the uncoated sample, and the corresponding wear rate is reduced by 6.1%, showing the synergistic effect of friction increase (FI) and wear resistance (WR). This frictional agent not only improves the working efficiency of the braking systems, but also exhibits high resistance to electrochemical corrosion, providing a practical and feasible solution for the high-performance braking in corrosion condition.