Tribological behavior of diamond-like carbon produced by rf-PCVD based on energetic evaluation

Two types of diamond-like carbon (DLC) were evaluated for their tribological behavior in terms of the tribometer input energy. The DLC samples were prepared from methane (denoted DLC[CH₄]) or benzene (denoted DLC[C₆H₆]) as a gas source on tungsten-carbide (WC) substrates by radio-frequency plasma chemical vapor deposition (rf-PCVD). The hydrogen contents of the DLCs were measured by Elastic Recoil Detection Analysis (ERDA). The DLC structures were investigated by Raman spectrometry and X-ray photoelectron spectroscopy (XPS). The basic mechanical properties, such as the hardness and the Young's modulus, were obtained by a nano-indenter. The DLC films against alumina were tribo-tested by a ball-on-disk. The input energy was calculated using the applied load, the friction coefficient, and the sliding distance in each tribo-test. The wear behavior of the DLC[CH₄] sample was better than that of the DLC[C₆H₆], even though the hardness of DLC[CH₄] was lower than that of DLC[C₆H₆]. The wear loss of DLC[CH₄] and DLC[C₆H₆] was evaluated by the input energy, and the wear resistance difference of the DLCs was characterized in terms of the input energy.