Lube ability of inactive media in the presence of carbon diamond-like coatings

Lube ability of inactive oil was examined under friction of steel specimens with and without some carbon diamond-like coatings. It was shown that the inactive oil - pure liquid paraffin provides better antifriction properties under friction tests of specimens coated by highly ordered monocrystalline carbon coating as compared with uncoated steel and amorphous coatings deposited on steel and titanium sub-strates. The obtained results can be explained by the difference in the level of molecular orientation in lube boundary layer depending on the level of solid surface i.e. carbon coating ordering.