Microstructure and high-temperature steam oxidation properties of thick Cr coatings prepared by magnetron sputtering for accident tolerant fuel claddings: The role of bias in the deposition process

Abstract

Thick Cr coatings sized ∼27 μm were deposited on Zr-4 substrates by magnetron sputtering to improve the high-temperature oxidation resistance of Zr alloys for accident tolerant fuel claddings. The effects of the bias on the microstructure, mechanical properties and high-temperature oxidation resistance of the thick Cr coatings were investigated systematically. Oxidation tests showed that the Cr coatings with a bias of −50 V exhibit excellent oxidation resistance after steam oxidation at 1200 °C for 120 min, and can be used as an accident-tolerant fuel candidate material. The mechanism of high-temperature oxidation was also discussed in detail.