Improved oxidation resistance of Cr-Si coated Zircaloy with an in-situ formed Zr 2 Si diffusion barrier

In the present study, the dense Cr and Cr 0.92 Si 0.08 coatings have been deposited on Zircaloy-4 substrates by the magnetron sputtering technique. The high-temperature oxidation resistance of coatings is evaluated in 1200 °C steam for 1–4 h. The Cr 0.92 Si 0.08 coating shows better oxidation resistance than the Cr coating. The in-situ formed Zr 2 Si diffusion barrier inhibits the mutual diffusion of Cr and Zr. And the formation of a Cr 2 O 3 /SiO 2 double-layer scale effectively improves the oxidation resistance of a single Cr 2 O 3 layer. The formation of the in-situ diffusion barrier, Cr 2 O 3 /SiO 2 scales and oxidation protection mechanisms of the Cr 0.92 Si 0.08 coating have been discussed in detail.