  The effect of graded or constant bias voltages (-40 V, -80 V and -40/60/80 V)
on size grain and surface defects of arc PVD deposited CrN films was
investigated. Corrosion resistance evaluated using electrochemical impedance
spectroscopy (EIS) and potentiodynamic curves (Tafel) and the mechanical
behavior evaluated by means of instrumented nanoindentation and scratch testing
was correlated with the microstructural changes. It was found that the bias
voltage variation affects corrosion behavior due to the presence of defects
(i.e. open voids, droplets) which also affects the failure mechanisms and
increasing spallation. High bias voltage (-80 V) increases nano-hardness and
the elastic modulus due to the dense microstructure of the CrN coating.
