Investigation of Friction Coefficient Evolution and Lubricant Breakdown Behaviour at Elevated Temperatures in a Pin-on-Disc Sliding System

Lemeng Zhang; Xiao Yang; Qunli Zhang; Yang Zheng; Xiaochuan Liu; Denis J. Politis; Omer El Fakir; Liliang Wang

doi:10.3390/psf2022004011

Physical Sciences Forum (Aug 2022)

Investigation of Friction Coefficient Evolution and Lubricant Breakdown Behaviour at Elevated Temperatures in a Pin-on-Disc Sliding System

Lemeng Zhang,
Xiao Yang,
Qunli Zhang,
Yang Zheng,
Xiaochuan Liu,
Denis J. Politis,
Omer El Fakir,
Liliang Wang

Affiliations

Lemeng Zhang: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Xiao Yang: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Qunli Zhang: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Yang Zheng: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Xiaochuan Liu: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Denis J. Politis: Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus
Omer El Fakir: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK
Liliang Wang: Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK

DOI: https://doi.org/10.3390/psf2022004011
Journal volume & issue: Vol. 4, no. 1
p. 11

Abstract

Read online

The lubricant behaviour at elevated temperatures was investigated by conducting pin-on-disc tests between P20 tool steel and AA7075 aluminium alloy. The evolutions of coefficient of friction (COF) at elevated temperatures showed three distinct stages: stage I (low friction stage), in which boundary lubrication was prevalent and the coefficient of friction was low; stage II (transient stage), in which the lubricant film thickness decreased to a critical value and the coefficient of friction increased rapidly; and stage III (breakdown stage), in which the lubricant was completely removed from the interface and the coefficient of friction was equal to its value under dry sliding conditions. In the present work, 2 types of water-graphite based lubricants were studied by pin-on-disc tests under different contact conditions. The effects of tooling and workpiece temperature determined from the experimental results were investigated in this paper and a comparison with an oil-graphite based lubricant was conducted.

Published in Physical Sciences Forum

ISSN: 2673-9984 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Technology (General): Mechanical drawing. Engineering graphics; Science: Chemistry: Physical and theoretical chemistry
Website: https://www.mdpi.com/journal/psf

About the journal

Abstract

Keywords