CrAlN/(CrVTaTiW)N_x nano-multilayer films were prepared using magnetron sputtering with varying the CrAlN layer thicknesses. The relationship between the CrAlN modulation layer thickness and the phase composition, microstructure, and mechanical properties of multilayer films was investigated. The results reveal that CrAlN/(CrVTaTiW)N_x multilayers possessed a single face-centered-cubic (FCC) crystal structure with NaCl-type phase structure. The GIXRR and TEM results reveal a well-defined periodic structure in the thin films. Furthermore, an accumulation of interface distortion and phase composition variations were observed as more layers along the growth direction were deposited. The increase in CrAlN layer thickness caused the formation of new phases, which affected the growth behavior of the new layer. The coherent epitaxial effect took place in all samples. As the thickness of the CrAlN layer increases, the (111) interplanar spacing decreases. The samples with 1.8nm CrAlN layer exhibited an maximum hardness and an elastic modulus of 25.8 GPa and 274.6 GPa, respectively. Furthermore, they also show an excellent crack resistance and plastic deformation resistance properties.
 

CrAlN/(CrVTaTiW)Nx; high entropy alloy nitride; hardness coating; mechanical properties; growth behavior