Preparation of Liquid Metal-based SiC/Graphene Binary Hybrid Nanofluid and Its Basic Properties as Hydraulic Transmission Medium.

Liquid metal (LM) with good room-temperature fluidity and high-temperature stability is an ideal base fluid for extreme high-temperature hydraulic transmission medium. However, the low viscosity and high density of LMs are not conducive to the sealing and lubrication performance of hydraulic components. Using Ga68.5In21.5Sn10 as the base fluid and SiC nanoparticles and graphene with good self-lubricity as a dispersed phase through homogenization and grinding, the novel LM-based SiC/Graphene binary hybrid nanofluid were prepared. The basic physical properties, rheological properties and lubricity at 25–200 °C of LM-based SiC/Graphene binary hybrid nanofluid at 0% 5 vol. %, 10 vol. %, 20 vol. % and 30 vol. % of nanoadditives were also explored. Compared with existing high-temperature hydraulic medium, LM-based SiC/Graphene binary hybrid nanofluid has excellent thermal stability, excellent heat dissipation performance, smaller temperature-viscosity changes, and good high-temperature lubricating performance. We selected 20 vol. % of the samples with the most suitable rheological and lubricating properties for hydraulic transmission medium and evaluated the volumetric efficiency and wear of the gear pump by introducing the samples into a hydraulic system. The results show that compared to pure LM, 20 vol. % of the sample can improve the volumetric efficiency of the gear pump and demonstrate good anti-wear performance. [ABSTRACT FROM AUTHOR]