Characterization of WC–CrAlN heterostructures obtained using a cathodic arc ion plating process

New WC–CrAlN heterostructure films were deposited on Si wafer and S45C steel substrate by a cathodic arc ion plating (CAIP) process. The Al concentration and bilayer repeat period (λ; 2–10 nm) were controlled to obtain a nano-layered structure. We have characterized our samples using X-ray diffraction (XRD), cross-sectional transmission electron microscopy (TEM) and electron diffraction patterns. Mechanical properties of the WC–CrAlN films were characterized using nano-indentation tests, residual stress evaluation and scratch testing. The microhardness of WC–CrAlN films was in the range of 30–43 GPa. The residual stress was reduced below 2 GPa and the adhesion strength obtained was approximately 50 N by alternative deposition of heterostructure (WC–CrAlN) and buffer (WC–Cr) layers.