TY - JOUR

T1 - Investigation of Graphene Platelet-Based Dry Lubricating Film Formation in Tribological Contacts

AU - Pape, Florian

N1 - Publisher Copyright: © 2024 by the author.

PY - 2024/3/18

Y1 - 2024/3/18

N2 - Dry lubricants used in highly loaded rolling bearings are in the focus of current research. In previous studies, graphene platelets applied as dry lubricants on the surfaces of angular contact ball bearings demonstrated superior properties. These specific bearings, experiencing both rolling and spinning motion, create more severe conditions for dry lubricants. To gain deeper insights into the lubrication effects, micro-tribological studies were carried out on the respective film formation and running behavior effects. In the tests, a fixed steel ball slid against an oscillating counterpart under a defined load. During the measurements, the applied load and tangential forces on the ball were recorded to calculate the friction. Comparative investigations included nano-graphite particles and fullerene as dry lubricants, in addition to graphene platelets of various staple thicknesses. To increase the adhesion of the films to the surfaces, a pre-rolling process was implemented. Afterwards, the friction on the compressed films was measured. The results indicate that the pre-rolling process effectively reduces the friction of the system. After testing, the surfaces underwent analysis using laser scanning microscopy to assess the formed films, wear, and material transfer. It has been demonstrated that the pre-rolling process leads to the formation of a very thin compacted film with surface protective properties. With the ball as a counterpart, the graphene platelets generate a transfer film on the contacting surface.

AB - Dry lubricants used in highly loaded rolling bearings are in the focus of current research. In previous studies, graphene platelets applied as dry lubricants on the surfaces of angular contact ball bearings demonstrated superior properties. These specific bearings, experiencing both rolling and spinning motion, create more severe conditions for dry lubricants. To gain deeper insights into the lubrication effects, micro-tribological studies were carried out on the respective film formation and running behavior effects. In the tests, a fixed steel ball slid against an oscillating counterpart under a defined load. During the measurements, the applied load and tangential forces on the ball were recorded to calculate the friction. Comparative investigations included nano-graphite particles and fullerene as dry lubricants, in addition to graphene platelets of various staple thicknesses. To increase the adhesion of the films to the surfaces, a pre-rolling process was implemented. Afterwards, the friction on the compressed films was measured. The results indicate that the pre-rolling process effectively reduces the friction of the system. After testing, the surfaces underwent analysis using laser scanning microscopy to assess the formed films, wear, and material transfer. It has been demonstrated that the pre-rolling process leads to the formation of a very thin compacted film with surface protective properties. With the ball as a counterpart, the graphene platelets generate a transfer film on the contacting surface.

KW - dry lubrication

KW - fullerene

KW - graphene platelets

KW - nano-graphite

KW - transfer film

KW - tribological contact

UR - http://www.scopus.com/inward/record.url?scp=85188846525&partnerID=8YFLogxK

U2 - 10.20944/preprints202312.1972.v1

DO - 10.20944/preprints202312.1972.v1

M3 - Article

VL - 14

JO - Coatings

JF - Coatings

SN - 2079-6412

IS - 3

M1 - 360

ER -