Effect of nanometer silicon dioxide on the frictional behavior of lubricating grease

Nanometer-silicon dioxide encapsulated in lithium grease is prepared, and the frictional behavior of the lithium grease and nanometer-silicon dioxide–contained lithium grease is compared with respect to the additive content, load, and frictional temperature in this article. The structure and morphology of nanometer-silicon dioxide is characterized by X-ray diffraction and scanning electron microscopy, respectively. Friction and wear tests were conducted on a four-ball friction and wear tester. The morphology of worn steel surface is analyzed by scanning electron microscopy and three-dimensional surface profiler. Results show that the addition of nanometer-silicon dioxide in grease can markedly improve the friction-reducing performance and anti-wear ability of base grease. When the nanometer-silicon dioxide in grease is 0.3 wt%, the friction coefficient and wear scar diameter decrease by 26% and 7% compared with base grease, respectively. The nanometer-silicon dioxide (0.3 wt%)–contained grease exhibits th...