An effort was made to study and characterize the tribological characteristics of diamond nanoparticles as compared to neat mineral oil in the presence of sliding contact typically observed in the standard ASTM D4172 four-ball test. Four-ball tests were conducted with a solution of diamond nanoparticles and mineral oil, both at varying run times and bulk oil temperatures, and a consistent reduction in wear rates was observed. Numerical simulations were performed; it was observed that by enhancing the thermal conductivity of the lubricant, the wear reduction rate was observed to match the diamond nanoparticles solution results remarkably. This effort provides evidence that this additive wear reduction is in part caused by reduced lubricant temperatures due to the enhanced conductivity of the diamond.
Study on the Scoring Resistance of Lubricating Oil in Four Ball Test : 3rd Report, Effects of Bulk Oil Temperature and Sliding Velocity in the Test Method According to JIS