Lubricant additives are the main means to improve the performance of lubricants.
In this article, green and inexpensive layered kaolin were selected as lubricant
additives, and the effects of the type of modifier, concentration, particle size
of kaolin additives, and working temperatures on the tribological performance of
lubricants were investigated. The results showed that the Span80 modifier can
effectively improve the dispersibility and friction reduction effects of kaolin
oil samples. Compared with kaolin oil samples without the modifier, the modified
kaolin oil can reduce the friction coefficient by 40.9% and the wear spot
diameter of the steel balls by 43.8%. The layered kaolin additive can
significantly reduce the friction coefficient and wear of steel balls in
lubrication, and the friction coefficient showed a trend of decreasing and then
increasing with increasing kaolin additive concentration and particle size. The
optimal added concentration and particle size of kaolin are 5 wt% and 2 μm,
respectively, which can reduce the friction coefficient by 41.9% and 65.63% and
the wear spot diameter by 12.31% and 50.72%, respectively, compared with the
base oil. At five temperatures, compared with the base oil, the kaolin oil
samples all showed better friction reduction and anti-wear properties. The micro
and nano size of the kaolin additive, the layered structure, and the chemically
reactive film generated on the surface are the main reasons for its good
lubrication performance.
