Investigation of the oxidation mechanisms of superlattice Cr-CrN/TiSiN-Cr multilayer coatings on Zircaloy substrates under high-temperature steam atmospheres

• DOI: 10.1016/j.corsci.2021.109782
• Publication Date: 2021-08-18T14:58:59Z
• Authors: Junkai Liu; Zhe Hao; Zhexin Cui; Dayan Ma; Junqiang Lu; Yanguang Cui; Chong Li; Wenbo Liu; Shijing Xie; Ping Huang; Guanghai Bai; Di Yun
• Keywords: Ion plating; Zirconium alloy

Abstract Cr-CrN/TiSiN-Cr multilayer coatings were deposited on Zircaloy substrates by multi-arc ion plating, and the microstructure and oxidation behavior of the as-deposited coatings, specifically the middle CrN/TiSiN layer, were investigated. The CrN/TiSiN layer exhibited a superlattice structure. The multilayer coatings effectively protected the Zircaloy substrates from oxidation. (Cr1-xTix)2O3 and Cr2TiO5 phases were produced in the coating after oxidation at 1200 °C for 1500 s. With oxidation time increases, most of the Cr atoms in these two phases were replaced by Ti atoms. Oxidation mechanisms of the as-deposited coatings are discussed and a decomposition model of the superlattice CrN/TiSiN layer is proposed.