Ti4+-incorporated fluorite-structured high-entropy oxide (Ce,Hf,Y,Pr,Gd)O2−δ: Optimizing preparation and CMAS corrosion behavior
Fuhao Cheng, Fengnian Zhang, Yufeng Liu, Meng Guo, Chufei Cheng, Jiadong Hou, Yang Miao, Feng Gao, Xiaomin Wang
Abstract
Abstract Environmental barrier coatings (EBCs) with excellent chemical resistance and good high-temperature stability are of great significance for their applications in next-generation turbine engines. In this work, a new type of high-entropy fluorite-structured oxide (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 )O 2− δ (HEFO-1) with different Ti 4+ contents were successfully synthesized. Minor addition of Ti 4+ could be dissolved into a high-entropy lattice to maintain the structure stable, effectively reducing the phase formation temperature and promoting the shrinkage of bulk samples. Heat treatment experiments showed that all the samples remained a single phase after annealing at 1200–1600 °C for 6 h. In addition, high-entropy (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 Ti 0.2 x )O 2− δ demonstrated great resistance to calcium—magnesium—alumina—silicate (CMAS) thermochemical corrosion. When the content of Ti was increased to x = 0.5, the average thickness of the reaction layer was about 10.5 after being corroded at 1300 °C for 10 h. This study reveals that high-entropy (Ce 0.2 Hf 0.2 Y 0.2 Pr 0.2 Gd 0.2 Ti 0.2 x )O 2− δ is expected to be a candidate for the next-generation EBC materials with graceful resistance to CMAS corrosion.