Oxidation Resistance and Mechanical Properties of Mo2N/MoSi2 Multi-Layer Films Prepared by Reactive Magnetron Sputtering

To investigate the properties of Mo2N/MoSi2 multi-layer films, pure Mo2N films, pure MoSi2 films, and Mo2N/MoSi2 multi-layer films with 4, 8, 12, 16, and 20 layers were prepared using magnetron sputtering. Before and after oxidation, the phase structure, morphology, and elemental composition of the films were analyzed using X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, and energy-dispersive spectroscopy. The mechanical properties of the films were characterized by nanoindentation. The results indicate that the Mo2N/MoSi2 multi-layer films consist of cubic Mo2N and hexagonal MoSi2. As the number of layers increases, the thickness of the Mo2N and MoSi2 individual layers gradually decreases, significant changes occur in the surface and cross-sectional morphology of the Mo2N/MoSi2 multi-layer films, and the average grain size decreases with an increase in the number of layers. The Mo2N/MoSi2 multi-layer films exhibit superior oxidation resistance compared to the pure Mo2N films. However, as the thickness of an individual layer increases, the oxidation resistance of the multi-layer films decreases. The hardness of Mo2N/MoSi2 multi-layer films increases from 21.65 ± 1.08 GPa for the 4-layer film to 32.14 ± 1.38 GPa for the 20-layer film.