Oxidation behavior, thermal stability, and the coating/substrate interface evolution of CrN-coated Zircaloy under high-temperature steam

CrN-coated Zircaloy samples were prepared by cathodic arc ion plating, and the microstructure, stability, and oxidation behaviors of the CrN coatings in high-temperature steams were comprehensively investigated. The CrN coating significantly increased the oxidation resistance of Zircaloy exposed to steam through the formation of a dense Cr2O3 oxide layer without cracking or spallation. Two different multi-layered coatings were produced after the steam exposures. The nitrogen diffusion properties of the CrN coatings during oxidation were examined. The internal oxidation of Zr particles inside the nitride coating was observed. A ZrN nano-twinned layer formed at the coating/substrate interface.

Automated summary

The study found that the CrN coating significantly enhances the oxidation resistance of Zircaloy in high-temperature steam by forming a dense oxide layer, reducing cracking and spalling. Two different multi-layered coatings were formed after oxidation, and internal oxidation of Zr particles within the nitride coating was observed.