Tribological Synergism Between Borates and Sn(Ⅱ) or Sn(Ⅳ) Compounds

摘要

Dibutyl tin and stannous dialkyldithiocarbamates were synthesized. A four-ball tester was used to evaluate the tribological performances of these additives plus organic borate in a mineral oil. The results indicate that the combination of an oil-soluble tin compounds such as dibutyl tin and stannous dialkyldithiocarbamates with organic borates gave better antiwear protection to base oil than either component separately. The surface examination of the rubbing zone indicated that the atomic concentration of tin produced on the boundary layers by such combinations was greater than those without borates. On the basis of the results of tribological and chemical investigation, an antiwear synergistic mechanism can be postulated in which borates with electron-deficient p orbits in boron catalyse the triboreduction of tin compounds on rubbing surfaces.