h-BN lamellar lubricant in hydrocarbon and formulated oil in porous sintered bearings (iron + h-BN)

We investigate the frictional performance of the hexagonal boron (h-BN) nitride, sintered into the porous iron bearing, with the lubricating hydrocarbon and formulated oils. It was established that the h-BN particles largely improved the tribological performance of the surfaces under contact between the porous bearing and a grey cast iron disc. The h-BN particles (platelets) released during wear reduces friction in a surfactant-free (no additive) lubrication. The hexagonal h-BN solid particles are able to form efficient friction-reducing lamellar sheets on the contacting surfaces. It was found that solubilization of h-BN particles by reverse micelles were not beneficial in reducing friction in lubrication with surfactant. The role played by the surfactant and its effect on h-BN particles lubrication were discussed with respect to reverse micelle and solubilization concepts.