Synthesis and characterization of multilayer CrN/ZrN coatings

In this study, multilayer CrN/ZrN coatings with various bi-layer periods (δ) were deposited by closed-field unbalanced magnetron sputtering and their compositions, crystalline structures and morphologies were characterized by auger electron spectroscopy (AES), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Additionally, the mechanical properties of the coatings were characterized by nano-indentation and wear tests. The XRD results showed that the diffraction peak of multilayer CrN/ZrN coatings is observable between the CrN (111) and the ZrN (111). This peak has a strong tendency to increase the intensity and sharpen the width as the substrate rotation speed increases, indicating that the grain size of the multilayer CrN/ZrN coatings gradually increases. The hardness of films was dependent on the bi-layer period (δ), and the maximum hardness and elastic modulus were approximately 31.8 GPa and 321.5GPa, respectively. Moreover, the results of the wear tests showed that the multilayer CrN/ZrN coatings exhibited greatly improved wear resistance compared to the monolithic CrN coatings.