The CrCN coatings were deposited by multi-arc ion plating with
different C2H2 flow rates. The effect of carbon content on micro-
structure, mechanical properties and tribological properties in
seawater has been investigated. The conclusions are summarized
as follows:
(1) With the increase of C2H2 flow rate, the concentration of C
atom increased gradually from 0 to 21.32 at%. The carbon
element mainly exists as Cr–C, sp2 and sp3 bonds.
(2) The friction coefficients of the coatings at varied C2H2 flow
rates show an apparent difference in seawater. The lowest
friction coefficient is gained at 10 sccm and highest at 0 sccm,
which are closed relate to the fraction of sp2 bond and
columnar structure of the coating. The graphite carbon exists
as sp2 bond in the coatings can greatly reduce the friction
coefficient. The columnar structure contributes to the more
micro-fracture during sliding in seawater.
(3) The lowest wear rate is gained at 10 sccm, where the maximum
depth of wear track is also lowest. This arises from the high