Synthesis and Property Characterization of Magnetron Sputtered SiC/Cr Coatings on Zr-Based Alloy

The SiC/Cr coatings were consecutively deposited by DC and RF magnetron sputtering on Zr-based alloy substrate.The influence of the Cr transition layer and RF sputtering power on the interfacial adhesion, film thickness and surface properties was investigated with X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive spectroscopy.The results show that the cubic crystalline Cr-transition layer strongly improved the surface and interfacial properties of the amorphous SiC coatings.To be specific, the Cr-layer increased the interfacial adhesion and ductility of the SiC coating and decreased the thermal-expansion coefficient difference between the SiC layer and substrate in high temperature steam oxidation.The SiC/Cr coatings significantly enhanced the surface oxidation resistance and fracture resistance in an environment of high temperature steam.