Graded composite diamond coatings with top-layer nanocrystallinity and interfacial integrity: Cross-sectional Raman mapping

- Structural characteristics and residual stresses were analyzed by Raman mapping.
- Nanocrystallinity of the coating was observed to deviate with increasing thickness.
- Tribological tests shown the significance and need for top layer nanocrystallinity.
- Graded composite coatings were proposed to realize thick nanocrystalline coatings.