[Zurück]

A.M. Bogus, I. Gebeshuber, A. Naveira-Suarez, R. Pasaribu:
"Effect of Base Oil Polarity on Micro and Nano Friction Behaviour of Base Oil +ZDDP Solutions";
Vortrag: 3rd Vienna International Conference on Nano-Technology, Wien; 18.03.2009; in: "Proc. of the 3rd Vienna International Conference Micro- and Nanotechnology - Viennano09", (2009), ISBN: 978-3-901657-32-0; S. 97 - 102.

Ball-on-disc tribo tests and atomic force microscopy
(AFM) were used to analyze the effect of base oil
polarity on the friction behaviour of steel-steel contacts
lubricated with base oil + zinc dialkyldithiophosphate
(ZDDP) solutions. Understanding the lubrication
properties of the first chemisorbed layer of additives on
work pieces yields important information for the
optimization of lubrication in various solutions, in
particular with regard to the type of additive and amount
needed.
To characterize the influence of oil polarity, two
reference base oils (hexadecane - non polar and
diethylenglycol - polar) were blended with different
concentrations of ZDDP-C4, and the solutions were
tested. A monolayer of base oil/additive solution is
deposited on an ASI 52100 steel plate and is scanned on
AFM contact mode under several rubbing time and
applied load conditions.
An AFM technique is developed to estimate
microscopic values of friction coefficients showing how
the oil polarity contributes to the differences in friction
behaviour of the solution due to the addition of ZDDP.
With different base oils (hexadecane - non polar base oil
and diethylenglycol - polar oil) we observed a
significant different of friction behaviour (in micro scale
and nano scale) due to the addition of ZDDP compared
to the base oil alone. This observation may be attributed
to the contribution of base oil to transport the ZDDP
additive onto the surface that will be discussed in more
detail below. This results display the importance of base
oil polarity on the friction behaviour of formulated
lubricants containing additives.
(i)

ZDDP, base oil polarity, friction