WS2 nanorods prepared by self-transformation process and their tribological properties as additive in base oil

WS2 nanorods with 10–15 nm in diameters and 0.1–2 μm in lengths were prepared successfully by self-transformation process from the precursor, which was obtained by high-energy ball milling. The tribological properties of WS2 nanorods as lubricating oil additive were investigated with a MMW-1 four-ball tribotester. By the addition of WS2 nanorods in base oil, the antiwear ability was improved and the friction coefficient was decreased. The oil with WS2 nanorods showed better tribological properties than the oil with 2H-WS2. A combination of the rolling effect between the rubbing surface and the formation of a thin physical tribofilm on the substrate can explain the good friction and wear properties of WS2 nanorods.