Cryogenic friction behavior and thermolubricity effect of graphene film on copper substrate

Abstract

Purpose The purpose of this paper is to reveal the mechanism of graphene low-temperature friction and provide a theoretical basis for the application of graphene. Design/methodology/approach A probe etching model of graphene on the copper substrate was established to obtain the friction pattern of graphene with different layers in the temperature interval from 100 to 300 K. The friction mechanism was also explained from a microscopic perspective based on thermal lubrication theory. Low-temperature friction experiments of graphene were carried out by atomic force microscopy to further verify the graphene low-temperature friction law. Findings Graphene nanofriction experiments were conducted at 230–300 K. Based on this, more detailed simulation studies were performed. It is found that the combined effect of thermolubricity and thermal fluctuations affects the variation of friction. For monolayer graphene, thermolubricity is the main influence, and friction decreases with increasing temperature. For multilayer graphene, thermal fluctuations gradually become the main influencing factor as the temperature rises, and the overall friction becomes larger with increasing temperature. Originality/value Graphene with excellent mechanical properties provides a new way to reduce the frictional wear of metallic materials in low-temperature environments. The friction laws and mechanisms of graphene in low-temperature environments are of great significance for the expansion of graphene application environments.

Superlubricity of Materials: Progress, Potential, and Challenges

“…Achieving superlubricity is a complex endeavor, dependent on multiple factors, including material properties, surface structures, environmental conditions, and even the scale at which it is studied. It can manifest in various forms, such as structural superlubricity [ 12 , 13 ], where the alignment of atoms on the sliding surfaces reduces friction, or thermolubricity [ 14 , 15 ], where temperature changes lead to a near-zero friction state. An understanding of these different mechanisms is crucial for harnessing the full potential of the superlubricity phenomenon.…”

“…When materials or lubricants are subjected to specific temperature ranges, their properties can undergo alterations, leading to a superlubric state. For example, Bai et al [ 14 ] studied the friction pattern of graphene with various layers at temperatures ranging from 100 to 300 K and investigated thermolubricity in cold environments using graphene. At the heart of thermolubricity is the concept of temperature-dependent material properties.…”