Magnetron sputtering deposition of polycrystalline CrN/ZrN superlattice coatings

The influence of substrate rotary speed, species of reaction gases and flows on nanoindentation, nanoscratch fracture, and residual stress were explored on reactive sputtered nanoscale CrN/ZrN multilayered coatings. Hardness and critical fracture load as high as 32 GPa and 85 mN with desirable compressive stress were achieved for this model. A proper percentage of NH3 in N-2 reaction gas was also proved to be of benefit to synthesize high-hard and fracture-resistant CrN/ZrN coatings. The low-angle XRD patterns provided the layer modulation period of the coatings. A marked polycrystallite of two-cubic NaCl phase CrN + ZrN as well as probably hexagonal Cr2N with small modulation period corresponded to the enhanced mechanical properties.