Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of CrMoNbZr Medium-Entropy Alloys Coatings

Abstract

A near-equimolar CrMoNbZr coating with low thermal neutron cross sections is prepared on zircaloy-4 substrate by radio frequency magnetron sputtering. The microstructure, mechanical properties, and surface wettability of the coatings prepared at different deposition temperatures are studied. The high-temperature corrosion resistance of the CrMoNbZr coatings is investigated by a 40 d autoclave corrosion test with pure water containing 3.5 ppm lithium, 1000 ppm boron at 320 °C. The results indicate that the CrMoNbZr coatings are mainly composed of body-centered cube-structured nanocrystals, and the coating deposited at 300 °C has superior high-temperature corrosion resistance and mechanical properties. Finally, the mechanism of high-temperature corrosion is elucidated.