Structural analysis of hydrogenated diamond-like carbon coatings prepared using magnetron sputtering

In this study, a series of hydrogenated diamond-like carbon (H-DLC) coatings were deposited using an unbalanced magnetron sputtering system. For hydrogenation, acetylene gas was used as the hydrogen source. The typical conditions for preparing DLC coatings were used, with additional acetylene gas being introduced into the depositing chamber. The acetylene flow rate was varied from 0 to 16 sccm at intervals of 4 sccm and finally set at 24 sccm. The chemical composition, microstructure, and phases of the resulting coatings were evaluated. Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, and Raman analysis were performed, and specific mechanical properties were examined. The results indicated that hydrogenation influenced the H-DLC coatings due to the formation of sp³ bonding. The coating prepared at a flow rate of 8 sccm of acetylene exhibited the highest hardness of 15.4 GPa because it had the highest number of sp³ bonds.