Hydrogenated amorphous carbon films on steel balls and Si substrates: Nanostructural evolutions and their trigging tribological behaviors

摘要

In this study, we prepared hydrogenated amorphous carbon films on steel balls and Si substrates (steel ball-and Si substrate-films) with different deposition time, and discussed their carbon nanostructural evolutions and tribological behaviors. The steel ball-film structure started to be graphite-like structure and then gradually transformed into fullerene-like (FL) structure. The Si substrate-film structure began in FL structure and kept it through the thickness. The difference may be result from the competition between high starting substrate temperature after additional nitriding applied on the steel balls (its supply power is higher than that in the film deposition), and relaxation of compressive stress from energized ion bombardment in film deposition process. The FL structural film friction couples could achieve ultra-low friction in open air. In particular, the Si substrate-film with 3h, against the steel ball-film with 2h and 3h, exhibited super-low friction (similar to 0.009) and superlong wear life (similar to 5.5 x 10(5) cycles). Our result could widen the superlubricity scope from previously high load and velocity, to middle load and velocity. (C) 2017 Elsevier B.V. All rights reserved.