Evaluation of friction properties in polished polycrystalline diamond films on steel substrates

CVD diamond films are expected to become a solid lubricant coating without any maintenance. However, substrates on which diamond film can be deposited are limited to silicon, tungsten carbides (TiC) and so forth. If diamond films can be deposited onto steel substrates, possible applications will increase in number. In this study, diamond film was deposited on a steel substrate with an interlayer and was partly polished. Tungsten and titanium were selected as materials for an interlayer between the diamond film and the SUS 440 C substrate. In a friction test, low and stable friction coefficients were obtained between the pair of diamond film and SKD 11 pin, with a friction coefficient of 0.1 in the steady-state regime. The diamond films on steel substrates show good friction properties similar to conventional diamond films on TiC substrates. Therefore, diamond films on steel substrates prove useful in obtaining solid lubrication films for sliders.