Enabling macroscopic superlubricity in TaC/a-C nanocomposite film by atomic-level Au

Endowing the hard protective coating systems with macroscopic superlubricity can adequately minimize unnecessary material consumption and energy waste caused by friction and wear. Herein, a novel scheme for realizing superlubricity-protective bifunction is demonstrated, namely introducing atomic-level dispersed Au atoms (similar to 1.4 at.%) into the TaC / amorphous carbon (a-C) nanocomposite structure consisting of the TaCnanoparticles-based network backbone and the a-C filler. With the aid of the atomic-level dispersed Au atoms reducing the ordered transformation barrier of a-C, the in-situ formation of graphite-like carbon (GLC) flakes during the sliding process wrap the TaC grains to form TaC@GLC nanoscrolls in the shearing layer for multicontact configuration and incommensurate contact, thereby obtaining the robust macroscopic superlubrication with the friction of coefficient of similar to 0.002 and the ultra-low wear rate of similar to 8.80 x 10 10 (mm(3)/Nm). This strategy of triggering in-situ self-assembled nanoscrolls from hard protective coatings provides a new avenue to enable macroscopic superlubricity for robust engineering applications.

Automated summary

By introducing atomic-level dispersed Au atoms into the TaC/a-C nanocomposite structure, a novel scheme for achieving superlubricity-protective bifunction is demonstrated. This results in the in-situ formation of TaC@GLC nanoscrolls during the sliding process, leading to robust macroscopic superlubrication with a friction coefficient of approximately 0.002 and an ultra-low wear rate of approximately 8.80 x 10 10 (mm(3)/Nm).