A. Murase et T. Ohmori, ToF-SIMS analysis of model compounds of friction modifier adsorbed onto friction surfaces of ferrous materials, SURF INT AN, 31(3), 2001, pp. 191-199
The adsorption of model compounds of friction modifiers on ferrous material
s has been investigated by time-of-flight secondary ion mass spectrometry (
ToF-SIMS). Eleven kinds of model compounds, including carboxylic acids, alc
ohols, amines and esters, were subjected to lubrication tests. Six compound
s among these-carboxylic acids and some amines and esters-showed good lubri
city. The ToF-SIMS spectra of the friction surfaces after being washed with
hexane showed that carboxylic acids formed Fe-carboxylates by reacting wit
h the ferrous material, and esters formed both Fe-carboxylates and Fe-alcoh
olates by reactions of hydrolysates of esters and the ferrous material. For
amines, no reaction products were detected but quasimolecular ions, sugges
ting physical adsorption, were detected from the friction surfaces. For alc
ohols, no adsorption or reaction was detected from the friction surface. Ho
wever, clear correlations were not found between the amounts of reaction pr
oducts or adsorbed materials and lubrication properties such as friction co
efficient and width of wear scar. Copyright (C) 2001 John Wiley & Sons, Ltd
.