Implanting MnO2 into Hexagonal Boron Nitride as Nanoadditives for Enhancing Tribological Performance
Xiaorong Chen, Wenting Chen, Linyi Zhang, Minli Zeng, Shiming Yang, Zanhe Yang, Oluwafunmilola Ola, Kunyapat Thummavichai, Nannan Wang, Yanqiu Zhu
Abstract
Hexagonal boron nitride nanosheets (h-BNNs) show great potential in the field of tribology due to their typical two-dimensional layered structure and are essential for replacing conventional sulfur/phosphate-containing additives. However, the large particle size and poor dispersion of h-BNs seriously restrict their green lubrication application. In this paper, MnO2@h-BNNs nanocomposites were successfully prepared by ultrasonically exfoliating a hydrothermal method. The tribological properties of MnO2@h-BNNs nanocomposites as lubricant additives in poly-alpha-olefin oil (PAO) were investigated. The results show the oil dispersed with 0.25 wt% MnO2@h-BNNs had the best friction reduction and antiwear effect with 42% and 11.2% reduction, respectively, compared with the plain oil. Through further wear surface analyzing, we verified the antiwear mechanism of additives in filling the micropits and grooves on the wear surface and forming a friction protection film including Fe2O3, MnO2, and BN on the wear surface, avoiding direct contact between the friction subsets. This can provide ideas for other lubricating oil additives.