Effect of microstructure and hydrogen content on the characteristics of amorphous hydrogenated carbon protective coatings

Amorphous hydrogenated carbon films have splendid wear characteristics as protective coatings. In the present work we have studied the relation between wear durability and microstructure of the amorphous hydrogenated carbon films prepared with radio‐frequency plasma‐enhanced chemical vapor deposition. Wear rates of pin‐on‐disk sliding tests for the films deposited at various conditions have been compared with the results of spectroscopic analysis. Wear durability of the films has been found to be described with a combination of two factors, one is the shoulder‐to‐main peak ratio of Raman spectra and the other is content of chemically bonded hydrogen atom. The former factor stands for the amount of ‘‘graphitelike’’ regions and the latter stands for the amount of ‘‘organic’’ regions in the carbon films.