CMAS corrosion behavior of a novel high entropy (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 thermal barrier coating materials

• Published in: Corrosion science 2023-11, Vol.224, p.111529, Article 111529
• Main Authors: Lin, Guangqiang, Wang, Yanli, Yang, Lingxu, Sun, Rongfa, Wu, Liankui, Zhang, Xiaofeng, Liu, Huijun, Zeng, Chaoliu
• Format: Article
• Language: English
• Subjects: CMAS corrosion; Fluorite structure; High entropy; High temperature; Rare earth zirconate; Thermal barrier coatings
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2023.111529

The CMAS corrosion behavior of a novel high entropy material (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 with thermal conductivity of 1.215 W·m−1·K−1 was investigated. Results show that a dense layer composed of apatite type RE8Ca2(SiO4)6O2 phase and RE/Ca-ZrO2 forms in front of the reaction layer, which dramatically decreases the infiltration rate of CMAS from 20 to 5.3 µm/h at 1300 °C. Moreover, the elements with a larger ion radius are easier to form apatite type phase to slow down the further infiltration of CMAS. This study reveals that the high entropy (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 ceramic is a promising candidate for TBCs with extreme resistance to CMAS corrosion. •The CMAS corrosion behavior of a novel high entropy ceramic with low thermal conductivity was investigated.•A dense layer composed of apatite phase and RE/Ca-ZrO2 forms in the front of the reaction layer.•The element with a larger ion radius is easier to form apatite type phase to slow down the infiltration of CMAS.•The element with a smaller ionic radius is more likely to participate in the stabilization of ZrO2.