Characterization of quaternary (Cr,Al)N-based films synthesized by the cathodic arc method

Chromium aluminum nitride based films were synthesized by the cathodic arc method using an alloy cathode, and annealed in a vacuum chamber at 800, 900 and 1000 °C. XRD analyses showed that the (Cr,Al,Si,Y)N films maintained a cubic phase up to 800 °C, but changed to a mixed phase after post-annealing at temperatures of more than 900 °C. Cr₂N segregation and partial transformation from a cubic to hexagonal phase at over 800 °C were confirmed for (Cr,Al,Si)N and (Cr,Al,Y)N. The lattice parameters for cubic (Cr,Al,Si)N and (Cr,Al,Y)N (0.416 nm) decreased to 0.411 nm and 0.413 nm, respectively, after annealing at 900 °C. The lattice parameter for (Cr,Al,Si,Y)N changed from 0.417 nm to 0.413 nm after annealing at 900 °C. The microhardness of (Cr,Al,Y)N was kept constant at 800 °C, whereas that of (Cr,Al,Si)N and (Cr,Al,Si,Y)N increased slightly between 800 and 900 °C. In this study, hardness, microstructure and lattice parameters were analyzed and discussed as a function of the annealing temperature.