Tribological performance of oil-based ZnO and diamond nanofluids

In previous studies, few articles investigated the tribological properties of nanofluid-lubricated ceramic specimens. Therefore, this research focused on the tribological performance of an alumina ball sliding against a steel plate lubricated with ZnO or diamond nanofluids using oleic acid as surfactant. The coefficient of friction obtained with various concentrations of ZnO and diamond nanoparticles was approximately constant at 0.08. Scanning electron microscopy (SEM) was used to explore the possible mechanisms of wear with the nanofluids. Generally, as the diamond or ZnO concentration of nanoparticles with oleic acid increases, the disk and ball wear increase. The higher concentration of nanoparticles leads to enhanced three-body abrasive wear. Diamond nanofluids produced higher ball wear than ZnO nanofluids. The hard diamond particles likely embedded in the disk and/or acted as third-body particles, which abraded the ball at a high rate.