High temperature steam oxidation behavior of textured Cr coatings with different grain structures

In order to improve the oxidation resistance of Zr-4 alloy in high temperature steam environment, Cr coatings with the 〈001〉 fiber texture were prepared on Zr-4 substrates by the high-power pulsed magnetron sputtering (HIPPMS) and direct current magnetron sputtering (DCMS) methods, and their structure and high temperature steam oxidation behavior at 1200 and 1300 °C were systematically investigated. The results showed that the fine grains of Cr coatings combined together to form large grains while the texture of the coatings was not changed during oxidation. Furthermore, cracks or defects formed during the combination of grain boundaries in the grain growth of DCMS Cr coating, providing paths for short-circuit diffusion of the oxidizing medium, which accelerated the oxidation of the Cr coating.