Morphology and composition of tribofilms deposited using tribochemical burnishing technique

Using a modified burnishing technique, low friction tribofilms can be formed on steel and cast iron surfaces in a controlled manner, before the part is mounted in e.g. an engine. The influence on the underlying substrate as well as the morphology and composition of the tribofilm has been thoroughly investigated in this paper. The coating process was found to smoothen rough plateaus, but not affecting deeper scratches and grooves, e.g. a honing pattern. The influence on the substrate was limited and no significant stresses were introduced in the surface. The tribofilm was mostly amorphous and typically 50–80 nm thick, composed of Fe, O and W, with minor additions of C and S.