Abstract:
Magnesium-doped zinc oxide (Zn0.92Mg0.08O)
(ZMO) nanoparticles of 23 nm particle size have been
synthesized by auto-combustion method. The variation in
particle size of these nanoparticles has been performed by
their further calcination at 800 and 1000 C for 2 h and the
corresponding calcined particles are designated as ZMO-1
and ZMO-2, respectively. The nanoparticles have been
characterized by powder-XRD, scanning electron microscopy (SEM), energy dispersive X-ray and transmission
electron microscope. The effect of particle size on the
antiwear lubrication behavior of paraffin base oil has been
investigated on four-ball lubricant tester. The tribological
tests of these nanoparticles as antiwear additives have been
studied at an optimized concentration (0.5 %w/v) by
varying load for 30 min test duration and by varying the
test durations at 392 N load. Various tribological parameters such as mean wear scar diameter, friction coefficient
(l), mean wear volume, running-in and steady-state wear
rates show that these nanoparticles act as efficient antiwear
additives and possess high load-carrying ability. From
these tribological tests it has been observed that the lubrication behavior of studied nanoparticles is strongly sizedependent. The best tribological behavior is shown by
nanoparticles of the smallest size, ZMO. Being sulfur,
halogen and phosphorous free, ZMO nanoparticles have
potential to be used as low SAPS lubricant additives. The
SEM and atomic force microscopy analysis of the worn
surfaces lubricated with ZMO nanoparticles at 392 N
applied load for 60 min test duration show drastic decrease
in surface roughness. The values of surface roughness of
different additives are in good agreement with their
observed tribological behavior
