(Ti,Al,Zr)N/(Ti,Al,Zr,Cr)N bilayer films were deposited on cemented carbide(WC-8%Co) substrates by multi-arc ion plating(MAIP) using two Ti-Al-Zr alloy targets and one pure Cr target.To investigate the composition,morphology,and crystalline structure of the bilayer films,a number of complementary methods of elemental and structural analysis were used,namely,scanning electron microscopy(SEM),energy disperse X-ray spectroscopy(EDS),and X-ray diffraction(XRD).Adhesive strength and mechanical properties of the films were evaluated by scratch testing and Vickers microindentation,respectively.It is shown that the resulting films have a TiN-type face-centered cubic(FCC) structure.The films exhibit fully dense,uniform,and columnar morphology.Furthermore,as the bias voltages vary from-50 to-200 V,the microhardness(max.Hv0.01 4100) and adhesive strength(max.>200 N) of the bilayer films are superior to those of the(Ti,Al,Zr)N and(Ti,Al,Zr,Cr)N monolayer films. (Ti, Al, Zr) N / (Ti, Al, Zr, Cr) N bilayer films were deposited on cemented carbide (WC-8% Co) substrates by multi-arc ion plating alloy targets and one pure Cr target. investigate the composition, morphology, and crystalline structure of the bilayer films, a number of complementary methods of elemental and structural analysis were used, namely, scanning electron microscopy (SEM), energy disperse X-ray Spectroscopy (EDS), and X-ray diffraction (XRD). Adhesive strength and mechanical properties of the films were evaluated by scratch testing and Vickers microindentation, respectively. It shows the resulting films with a TiN-type face-centered cubic FCC) structure. The films exhibit fully dense, uniform, and columnar morphology. Fluorrthermore, as the bias voltages vary from -50 to -200 V, the microhardness (max.Hv0.01 4100) and adhesive strength (max. ) of the bilayer films are superior to those of (Ti, Al, Zr) N and (Ti, Al, Zr, Cr) N monolayer films.