The coatings' nano-impact
fatigue fracture resistance was assessed by the final measured impact
depth and confirmed by microscopic analysis of impact craters. Four
repeat micro-scratch tests to 5 N were run for each coating as threescan
topography-scratch-topography experiments using a R = 25 μm
probe. In the scratch scan after 250 μm the load was linearly ramped
at 150 mN/s to reach a peak load of 5 N at 420 μm and then kept
constant at this value until the end of the scratch track after 600 μm.
Analysis of the on-load depth and residual depth data after correction
for frame compliance, topography and slope allows true depth data to
be displayed and the location of first coating failure to be determined.