A New Pathway for Superlubricity in a Multilayered MoS2-Ag Film under Cryogenic Environment

A fundamental cryogenic study in tribology from 20 to 300 K revealed that a kind of disulfide film could exhibit a superlubricity state. Inspired by this, we designed a more delicate experiment and reported an extremely low friction coefficient for a multilayered MoS2-Ag film in a cryogenic environment against a bare steel ball under a high load. The results showed that the multilayered MoS2-Ag film could undergo a pressure exceeding 2 GPa to maintain a superlow friction coefficient of below 0.001 at 170 K. The film material was transferred to the sliding contacts to form an antifriction tribofilm. The superlubricity mechanism was attributed to the formation of MoS2-wrapped Ag nanoparticles accumulated at the sliding interface through nanoparticle movement and layered-structure sliding. This new kind of multilayered MoS2-Ag film provides a novel design for a solid lubricant and broadens the application of solid lubrication films under harsh working conditions for mechanical engineering.

Automated summary

A fundamental cryogenic study in tribology identified a superlubricity state exhibited by a disulfide film, leading to the design of a multilayered MoS2-Ag film with extremely low friction coefficient in a cryogenic environment. The film's superlow friction coefficient of below 0.001 under high load at 170 K was attributed to the formation of MoS2-wrapped Ag nanoparticles at the sliding interface. This new type of solid lubricant film offers a novel solution for mechanical engineering applications in harsh working conditions.