Abstract:
In order to better understand the lubricating
properties of diesel fuel, species that were present on tribological
surfaces were investigated using secondary ion
time-of-flight mass spectrometry (TOF–SIMS). Traditionally,
only certain species that are expected to be present at
the interface are investigated and their presence or absence
is used to make conclusions regarding the mechanism of
lubrication. In this work, an alternative and complementary
approach to data analysis and interpretation is proposed,
previously demonstrated for TOF–SIMS and based on
multivariate analysis methods, where the mass spectral data
are investigated more comprehensively. The main objective
was to interpret variation within and between different
areas of a tested surface and ultimately to contribute to the
understanding of the tribochemical reactions that occur at
the interface. The validity of this approach was confirmed
when the palmitate ion (which would normally be targeted)
was shown to contribute significantly (together with other
ions) to chemical differences between scratched and
unscratched areas of the surface.
