Irfan Nadeem (Author), Bojan Ambrožič (Author), Goran Dražić (Author), Janez Kovač (Author), Albano  Cavaleiro (Author), Mitjan Kalin (Author)

Abstract

Reducing friction is a promising strategy to decrease material losses and energy consumption in industrial systems. However, in aqueous-lubricated steel contacts, the contact pressure rarely exceeds 50 MPa during super-low friction due to excessive wear. This work demonstrates that even in steel/steel contacts, by combining graphene quantum dots (GQDs) with aqueous glycerol, it is possible to maintain super-low friction (µ ≈ 0.012) under a contact pressure as high as 316.5 MPa. Moreover, the use of GQDs improved the wear performance by 98 % compared to pure aqueous glycerol due to the formation of a tribochemical film, resulting from the electrostatic adsorption of GQDs on the positively charged sites on the worn surface. In particular, the exfoliation of graphene sheets within GQDs, the shearing of graphene layers inside the GQDs, and the OH–OH repulsion between the asperities shortens the running-in period and consequently reduces the friction and wear. At the same time, the formation of a chemically adsorbed tribofilm containing friction-induced structurally degraded GQDs protects the surface from wear and facilitates the maintenance of super-low friction at high contact pressures by improving the load-carrying capacity. This study suggests that green nano-lubricants based on GQDs have immense potential in sustainable engineering.

Keywords

materiali;grafen;kvantne pike;tribologija;trenje;obraba;materials;graphene;quantum dots;tribology;friction;wear;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FS - Faculty of Mechanical Engineering
UDC: 539.92
COBISS: 200420867 Link will open in a new window
ISSN: 0264-1275
Views: 55
Downloads: 23
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary keywords: materiali;grafen;kvantne pike;tribologija;trenje;obraba;
Type (COBISS): Article
Pages: str. 1-14
Issue: ǂVol. ǂ244, [article no.] 113111
Chronology: Aug. 2024
DOI: 10.1016/j.matdes.2024.113111
ID: 24512079