Search

The aim of the present study is to examine the antiwear, antifriction, and extreme pressure performance of castor oil with nano-additives by using a four-ball tester. CeO2 (~90 nm) and polytetrafluroethylene (~150 nm) nanoparticles were used as an additive in castor oil with four different concentrations in the range of 0.1-1.0% w/v. The suspension stability of the nanoparticles was improved by using sodium dodecyl sulfate as a dispersant. Different analytical tools were used to characterize the nanoparticles parameter (i.e. shape and size) as well as the worn surfaces. The additive concentration was optimized on the basis of tribological performance. The test results of antiwear and extreme pressure property have been reported on the basis of wear scar diameter and weld load, respectively. For the antiwear test, it was observed that the maximum reduction in the wear scar diameter was 37.4 and 35.3% at an optimum concentration of CeO2 and polytetrafluroethylene additive, respectively. Also, antifriction and load carrying properties of castor oil were significantly improved with the addition of nanoparticles as an additive in a small amount. The mechanism for such improvement in the tribological behavior has also been discussed. [ABSTRACT FROM AUTHOR]

In the present study, tribological properties of castor oil have been investigated with and/or without use of additives by using four-ball tester. In the base castor oil, calcium-copper-titanate nanoparticles (CCTO) and zinc dialkyldithiophosphate (ZDDP) were added in different concentrations (i.e., 0.1, 0.25, 0.5, and 1.0 w/v%) to study their individual effect on tribological performance. Tribological test results have shown that there is an improvement in the antiwear, extreme-pressure (EP) properties at 0.25 and 1.0 w/v% for both the additives, respectively. However, in the coefficient of friction (COF) test (incipient seizure load), an optimum concentration of 0.5 w/v% was observed for ZDDP additive, whereas CCTO nanoparticles have shown similar level of performance at all concentrations. The worn-out surfaces were analyzed by using different analytical tools. [ABSTRACT FROM AUTHOR]