Protection of Zr Alloy under High-Temperature Air Oxidation: A Multilayer Coating Approach

Metallic Cr and multilayer CrN/Cr coatings with a thickness of 2.5 µm were deposited onto E110 alloy by magnetron sputtering. Oxidation tests in air performed at 1100 °C for 10–40 min. The gravimetric measurements showed better protective properties comparison metallic coating. Multilayer coating prevented fast Cr–Zr inter-diffusion the formation ZrN layer beneath appearance is caused interaction nitrogen formed from decomposition CrN to Cr2N phases. Optical microscopy revealed residual (0.25 µm)/Cr µm) all oxidation periods. Additional situ X-ray diffraction (XRD) studies coated during linear heating up 1400 that Cr2Zr phase case occurred higher (~150 °C) temperature compared Cr. can decrease effect Zr oxidation. Uniform thinner oxide layers observed when applied. highest resistance belonged step 0.25 µm.