Effect of Bias Voltage on the Microstructure, Mechanical Properties, and High-Temperature Steam Oxidation Behavior of Cr Coatings Prepared by Magnetron Sputtering on Zircaloy-4 Alloy

This study investigated the effect of bias voltage on the microstructure, mechanical properties, and high-temperature steam oxidation behavior of the Cr coatings on the Zircaloy-4 alloy. By changing the bias voltage (0, − 50, − 100, − 150 V), Cr coatings with different orientations, including (110), (200), and (211), were obtained. Among these different samples, the Cr coating deposited at − 50 V exhibited a highly (211) preferred orientation, the lowest surface roughness, the highest deposition rate, and the best mechanical properties. Furthermore, after steam oxidation at 1200 °C for 30 min, the Cr coating with a (211) preferred orientation demonstrated superior oxidation resistance compared to those with (110) and (100) preferred orientations. This research is expected to provide new guidance for optimizing the structural design of Cr-coated nuclear fuel cladding, thereby extending accident tolerance.