Tungsten-doped diamond-like carbon (DLC) coatings have been magnetron sputtered with chromium and chromium/tungsten carbide dual interlayers onto 410 stainless steel rods. The surface finish (Ra) of the substrate before deposition was 0.10–0.25 μm for a set of rough rods and 0.05 to 0.10 μm for a set of smooth rods. SEM analyses revealed different kinds of flaws in the as-deposited films (virgin coating). Two samples, one from each set, were fatigue tested under uni-axial tension to determine the effect of the substrate surface roughness on the performance of the coating. Surface analysis revealed a different response between films deposited on rough and smooth substrates. Severe failure modes such as spalling and wide cracks developed from initial film flaws in the rough substrate sample. Cracks and film spalling were also observed in the smooth substrate sample but the severity, in terms of crack dimensions and density was considerably lower than the rough substrate sample.

This content is only available via PDF.
You do not currently have access to this content.