Facilitating macroscopic superlubricity through electric stimulation with graphene oxide nanosheet additives for steel surface lubrication

Achieving macroscopic superlubricity in electric environments on steel surfaces remains a challenge. This study achieved macroscopic superlubricity on steel surfaces by employing graphene oxide (GO) nanosheet additives with electric stimulation. Multiple factors were studied regarding the effect on lubrication performances. The morphology of the GO adsorption film on the intermittent contact surface (disc) is the main factor affecting the COF, as the continuous contact surface (ball) is required to overcome the peaks of GO film during sliding. The mechanism underlying the friction reduction is concluded as follows: when the intermittent contact surface (disc) was the positive pole, negatively charged GO migrated towards it, forming an adsorption film on its surface. The surface layer orientation of the GO film is relatively smooth, attributed to its contact with the negative pole (ball), resulting in friction reduction. This study illustrates the feasibility of achieving macroscopic superlubricity on steel interfaces through electric stimulation, thereby laying the groundwork for practical applications of superlubricity in engineering contexts, particularly in electric environments.