Carbon was introduced into the CrN coating to form the CrCN
coating. The nanocrystalline/amorphous structure in combined
with the hard Cr7C3 phase formation resulted in the superior
mechanical properties of the CrCN coating than the CrN coating.
The dense matrix led to the better anti-corrosion performance of
the CrCN coating than the CrN coating in seawater. More impor-
tantly, the carbonaceous phase formed inside the coating and the
graphite-like material generated on the friction contact surface
endowed the CrCN coating lower friction coefficient than the CrN
coating not only in ambient air but also in distilled water and
seawater. Due to the superior mechanical properties, the better
anti-corrosion performance and the lower friction coefficient, the
CrCN coating exhibited lower wear rate than the CrN coating in
seawater, which demonstrated the great potential of the CrCN
coating.