Superlubricity of molybdenum disulfide subjected to large compressive strains

Abstract

The friction between a molybdenum disulphide (MoS2) nanoflake and a MoS2 substrate was analyzed using a modified Tomlinson model based on atomistic force fields. The calculations performed in the study suggest that large deformations in the substrate can induce a dramatic decrease in the friction between the nanoflake and the substrate to produce the so-called superlubricity. The coefficient of friction decreases by 1–4 orders of magnitude when a high strain exceeding 0.1 is applied. This friction reduction is strongly anisotropic. For example, the reduction is most pronounced in the compressive regime when the nanoflake slides along the zigzag crystalline direction of the substrate. In other sliding directions, the coefficient of friction will reduce to its lowest value either when a high tensile strain is applied along the zigzag direction or when a high compressive strain is applied along the armchair direction. This anisotropy is correlated with the atomic configurations of MoS2.

Macroscale superlubricity achieved via hydroxylated hexagonal boron nitride nanosheets with ionic liquid at steel/steel interface

“…Nowadays, superlubricity, including solid superlubricity [5] and liquid superlubricity [6], has attracted continuously attention in many fields including machinery, energy, aerospace, and biology [7][8][9][10]. As for solid superlubricity, the achievement of extremely low COF (< 0.01) usually relied on a specific structure (e.g., graphite, MoS 2 , a-C:H, and diamond like carbon (DLC) film) [11][12][13][14][15] or a certain atmosphere (e.g., inert gas and vacuum) [16][17][18]. However, for liquid superlubricity, it is much easier to obtain common friction pairs in the atmosphere; therefore, it has wider application.…”

A review of advances in tribology in 2020–2021

“…It was found that due to the existence of two-dimensional graphene sheets, the contact area Fig. 82 Effects of grain boundary or in-plain strain on wear or superlubricity of 2D materials [967,968,971,973]. Reproduced with permission from Ref.…”

“…[971], © The author(s), 2021; Reproduced with permission from Ref. [973], © The author(s), 2022. of DLC-CNS is smaller than that of DLC-CND, which inhibited the movement of CNS, thereby reducing the frictional dissipation of the system and effectively improving the lubricity of CND. The excellent lubricity obtained by using 2D graphene sheets as the additive phase of composites has also aroused the interest of researchers.…”

“…On the basis of two-dimensional materials, researchers have also carried out many explorations on the theoretical research and realization of superlubricity. Wu et al [973] analyzed the friction between MoS 2 nanoflakes and MoS 2 substrates using an atomistic force fields-based modified Tomlinson model (Fig. 84(d)).…”

Tribological characteristics of three-body abrasive wear on MoS2 films

“…In practice, the movement pattern (i.e., the self-rotation and sliding) of the abrasive particle, as well as the unavoidable defects, can pose dramatic impacts on the tribological performance of the protection film [23][24][25][26][27]. Until now, Nanoscratching (i.e., two-body contact) is mostly adopted to characterize the frictional behaviors of the film [28][29][30], while few studies take attention to the atomistic modeling and simulation of three-body contact of the MoS2 film.…”