Abstract:
Reduction of friction and wear is an ongoing challenge in design and operation of machines and
implanted joints. Wear shorten the life of contacting parts. Inclusion of nanoparticles in modern
era has emerged as promising solution. Various nanoparticles act as lubricant additives like silver,
diamond and copper oxide nanoparticles. Many lubricants are used as base lubricants like
dodecane, mineral base oil, polyethylene glycol, fully formulated oil and polyalfaolefin oil.
Molybdenum disulfide 𝑀𝑜𝑆2 particles are modeled in Polyalphaolefin base oil. The effect of
𝑀𝑜𝑆2 nanoparticles on real contact area has also been modeled. There is suitable concentration
below which nanoparticles cannot reduced friction force. On the basis of results it is stated that
nanoparticles have dual effect. Inclusion of direct and indirect method to solve overall contact
problem.
To study the effect of addition of nanoparticles in synthetic base oils, a mathematical model has
been formulated. It is a multisacle model comprising a rough surface sub contact model and
statistical sub contact model. Rough surface contact model are based on micrometer sized
roughness features while statistical contact model are based on modeling of nanoparticles in
between rough surfaces. This contact model can also be used for other nanoparticles of same size
and roughness.
The model is verified using existing experimental data. Parametric study is done, varying the
load, particle size and particle weight fraction. COF and wear is evaluated and discussed.
