Effect of h-BN on Tribological Properties of Food Grade Composite Aluminum-Based Grease

In order to improve the tribological properties of food-grade composite aluminum-based grease, h-BN with different mass fractions were added to the based grease. The study mainly focused on the effects of h-BN with different mass fractions on the rheological properties and tribological properties of the composite aluminum-based greases at the temperatures of 25 and 150 ℃, and the survival rate of human colon adenocarcinoma cells (Caco2) in contact with the lubricating material. The results showed that the prepared composite aluminum-based grease exhibited excellent physicochemical properties, thermal stability, and structural integrity, all of which were superior to the commercially available grease (FM222). At the temperatures of 25 and 150 ℃, compared with the based grease, the friction coefficient of the composite aluminum-based grease containing 3.0% h-BN decreased by about 17.4% and 38.1%, respectively. The corresponding wear volume decreased by 51.5% and 51.4%, respectively. At different temperatures, the decrease in wear volume of the rubbing surface was similar, which might be due to the interlayer slips effect that could be exerted. These results also indicated that the anti-friction and anti-wear performance was superior to those of FM222. In addition, the cell survival of the composite aluminum-based grease, the grease containing 3.0% h-BN and FM222 were all above 90% with no observable changes in cell morphology, indicating that all three composite aluminum-based greases possessed the safety. Furthermore, the interlayer slips and repair effects of h-BN between the rubbing surfaces effectively improved the tribological properties of the composite aluminum-based grease. This study provided valuable insights for the development of novel food-grade lubricating materials.