Abstract: Serpentine ultrafine powders were prepared by hydrothermal method, and the structure and morphology of the powder were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The effects of powders prepared at different reaction temperatures and their dosages on tribological properties of 68# water-glycol hydraulic fluid were studied by using four-ball tester, and the mechanism of anti-wear and friction reduction was discussed. The results showed that the microstructure, chemical composition and crystal form of the hydrothermally synthesized serpentine powder at different temperatures were different. The hydrothermal synthesis product below 200°C was a mixture of serpentine, brucite, etc., and the serpentine powder synthesized by hydrothermal method at 200°C or above 200°C was a hollow tubular nanofiber serpentine. When using the nano-fiber serpentine powders prepared at 200°C and the adding amount was 0.06 % of the mass of water-glycol hydraulic fluid, the comprehensive tribological performance of water-glycol hydraulic fluid was the best. The friction coefficient and the wear spot diameter were 0.0562 and 0.39 mm, respectively, which were 18.07% and 33.90% lower than those of the basic hydraulic fluid, respectively. The morphology and energy spectrum analysis showed that serpentine powder added to hydraulic fluid can fill furrowing and repair the surface of wear marks, so as to achieve anti-wear and anti-friction.

Key words: hydrothermal, ultrafine serpentine powder, water-glycol hydraulic fluid, tribological property