Super-Lubricious, Fullerene-like, Hydrogenated Carbon Films

Abstract

Almost one-third of minimal energy is consumed via friction and wear process. Thus, to save energy using advanced lubrication materials is one of the main routes that tribologists are focused on. Recently, superlubricity is the most prominent way to face energy problems. Designing promising mechanical systems with ultra-low friction performance and establishing superlubricity regime is imperative not only to the most greatly save energy but also to reduce hazardous waste emissions into our environment. At the macroscale, hydrogenated diamond-like carbon (DLC) film with a supersmooth and fully hydrogen terminated surface is the most promising materials to realize superlubricity. However, the exact superlubricity of DLC film can only be observed under high vacuum or specific conditions and is not realized under ambient conditions for engineering applications. The latest breakthrough in macroscale superlubricity is made by introducing fullerene-like nano-structure and designing graphene nanoscroll formation, which also demonstrates the structure-superlubricity (coefficient of friction ~0.002) relationship.Thus, it is very interesting to design macroscale superlubricity by prompting the in situ formation of these structures at the friction interfaces. In this chapter, we will focus on fullerene-like hydrogenated carbon (FL-C:H) films and cover the growth methods, nanostructures, mechanic, friction properties and superlubricity mechanism.