Figure 2 reveals that adding more graphite particles is not recommended and sometimes can have a negative effect on the COF. Therefore, using solid lubricant in liquid lubricants needs an “optimal concentration”. The optimum values of the COF were obtained in the presence of 0.7 wt % graphene into oil. Particle additive concentrations below the optimum concentration resulted in insufficient load carrying capacity. On the contrary, when the particle additive concentration was above the optimum concentration, the excessive additive in the base oil decreased the load carrying capacity due to the formation of lumps in the interface which resulted in worse lubricating efficacy.
Figure 2. The variation of coefficient of friction (COF) and COF improvement in different weight percentage of graphite and graphene.
For more information please refer to the full article (below link)
- This article is an adaptation of “Effect of Micro- and Nano-Sized Carbonous Solid Lubricants as Oil Additives in Nanofluid on Tribological Properties” (on MDPI) by Emad Omrani, Pradeep L. Menezes and Pradeep K. Rohatgi, and is used under a CC-BY-4.0 International license.