Harnessing nano oil reservoir network for generating low friction and wear in self-mating alumina

This study unleashes the potential of nanoporous connected networks as excellent oil reservoirs for reducing friction and wear in Al<inf>2</inf>O<inf>3</inf>-Al<inf>2</inf>O<inf>3</inf> tribo-pairs. Alumina were fabricated via slip casting and sintering to generate wide-ranging densifications (70–99.5%) and slid in a reciprocating flat-on-flat configuration. Friction coefficients (FCs) lie between 0.025 and 0.37 which decreased with an increase in normal load (10–220 N), lubricant's viscosity (19, 289 mPa·s) and sliding frequency (6, 12, 24 Hz). A central finding is that FCs of infused specimens are smaller than those of surface lubricated. Wear rates decreased from 10⁻⁵ to <10⁻⁸ mm³·N⁻¹·m⁻¹ for an increase in Al<inf>2</inf>O<inf>3</inf> density. Wear occurred predominantly via intergranular and transgranular fracture modes as revealed by the electron microscopy studies.