Effect of modulation period on the mechanical and tribological behavior of (CrNbTiAlV)CN/MoN coatings

This work is to deposit (CrNbTiAlV)CN/MoN coatings by alternating sputtering with multiple targets. The hardness and elastic modulus of the (CrNbTiAlV)CN/MoN multilayer coatings gradually increase with the decreasing of the modulation period from 420 to 110 nm; however, the values decrease on the multilayer coating with a modulation period of 50 nm. As the modulation period decreases, the characteristic of MoO₃ debris changes from large flakes to smooth transfer tribolayers and then to small particles. The coating with a modulation period of 110 nm has a minimum friction coefficient and wear rate of about 0.11 and 4.4 × 10^–6 mm³/(N m) at 500°C, respectively. This can be attributed to the fact that it has the best resistance to plastic deformation and tends to form smooth transfer tribolayers.