HUMPHREY, E. ... et al., 2019. Multiscale boundary frictional performance of diamond like carbon coatings. Tribology International, In Press.
This paper investigates the frictional performance of a PECVD hydrogenated undoped DLC coating
and the alternative super-finished gear steel surface pairs. A tribometer replicates the conditions found
in the conjunction of a performance racing transmission spur gear pair. In mixed and boundary regimes
of lubrication the DLC contact is shown to have a lower coefficient of friction despite having
comparable surface topography when measured using optical interferometry. To determine the
mechanisms responsible for improved friction of DLC coated tribo-pairs atomic force microscopy is
used. It is shown that the nanoscale surface topography of the investigated PECVD DLC coated pairs
reduces the real asperity contact area formed at the same load carrying capacity. This highlights a
contributing mechanism for improved friction with the DLC coating.
This paper is in closed access until 30th Dec 2019.
The authors would like to express their gratitude to the Engineering and Physical Science Research
Council (EPSRC) for the financial support extended to this research through the Doctoral Training