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

• Published in: Materials & design Vol. 206; p. 109821
• Main Authors: Rowthu, Sriharitha, Deshpande, Pushkar, Annamalai, Adithyan, Hoffmann, Patrik
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2021; Elsevier
• Subjects: Abrasive wear; Nanoporous alumina; Oil infusion; Perfluoropolyether; Oil infusion; Perfluoropolyether; Nanoporous alumina; Abrasive wear
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2021.109821

[Display omitted] •Fomblin® Y25/6 oil is an excellent lubricant for self-mating nanoporous alumina.•90% Al2O3 relative density is the optimal in the range of 70–99.5% for achieving best tribological properties.•Friction coefficients decreased with increase in normal loads (10–220 N) and sliding frequencies (1–24 Hz).•Lowest friction coefficient of 0.025 was recorded for 95% dense self-mating lubricated Al2O3.•Wear occurred by intergranular fracture in 70–90% dense Al2O3 and transgranular fracture in 95–99.5% dense Al2O3. This study unleashes the potential of nanoporous connected networks as excellent oil reservoirs for reducing friction and wear in Al2O3-Al2O3tribo-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 Al2O3 density. Wear occurred predominantly via intergranular and transgranular fracture modes as revealed by the electron microscopy studies.