An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering. The multilayer design enhanced the substrate–coating compatibility, achieving a critical load of 87.8 N. Silicon doping induced nanocrystallization and amorphization, increasing the hardness to 26 GPa. At high temperatures, a nanoscale Cr-rich (Cr,Al) 2 O 3 layer was formed, effectively inhibiting oxygen diffusion. The coating underwent unique phase transformations, during which Cr 2 N and amorphous Si 3 N 4 were converted into dispersed SiCr 3 nanoparticles, which stabilized Cr atoms and suppressed their outward diffusion. Ab initio molecular dynamics simulations revealed that Cr atoms exhibited higher chemical activity and oxygen-capture capability than Al atoms and Si atoms served as diffusion barriers by pinning onto the oxidized surface, considerably improving the oxidation resistance of the coating.
LIU et al. (Sun,) studied this question.