Effects of hydrogen and oxygen on the electrochemical corrosion and wear-corrosion behavior of diamond films deposited by hot filament chemical vapor deposition

A diamond film was deposited on silicon substrate using hot filament chemical vapor deposition (HFCVD), and H2 and O2 gases were added to the deposition process for comparison. This work evaluates how adding H2 and O2 affects the corrosion and wear-corrosion resistance characteristics of diamond films deposited on silicon substrate. The type of atomic bonding, structure, and surface morphologies of various diamond films were analyzed by Raman spectrometry, X-ray diffraction (XRD) and atomic force microscopy (AFM). Additionally, the mechanical characteristics of diamond films were studied using a precision nano-indentation test instrument. The corrosion and wear-corrosion resistance of diamond films were studied in 1 M H2SO4 + 1 M NaCl solution by electrochemical polarization. The experimental results show that the diamond film with added H2 had a denser surface and a more obvious diamond phase with sp3 bonding than the as-deposited HFCVD diamond film, effectively increasing the hardness, improving the surface structure and thereby improving corrosion and wear-corrosion resistance properties. However, the diamond film with added O2 had more sp2 and fewer sp3 bonds than the as-deposited HFCVD diamond film, corresponding to reduced corrosion and wear-corrosion resistance.