Preparation of (RE0.5Yb0.5)2Si2O7 (RE=Sc, Er, or Yb) bulk ceramics and their corrosion behaviors by molten calcium-magnesium-aluminum-silicate at 1500 °C
作者
单位
1. Key Laboratory of Pressure System and Safety、Ministry of Education、East China University of Science and Technology、Shanghai 200237、China、2. Shanghai Institute of Aircraft Mechanics and Control、Shanghai 200092、China、3. Aviation Key Laboratory of Science and Technology on advanced Corrosion and Protection for Aviation Material、AECC Beijing Institution of Aeronautical Materials、Beijing 100095、China
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
The demand for high operating temperatures in gas turbine engines requires an urgent need for environmental barrier coatings (EBCs) materials that exhibit excellent resistance to molten calcium-magnesium-aluminum-silicate (CMAS) glasses. In this study, three types of (RE0.5Yb0.5)2Si2O7 (RE=Sc, Er, or Yb) bulk ceramics were prepared using an in -situ solid -phase reaction method, and their CMAS corrosion behaviors were investigated at 1500 °C. The results indicated that all the prepared bulk ceramics exhibited high densification and β -disilicate phase purity, and they showed both dissolution and penetration phenomena under CMAS corrosion at high temperatures. For Yb 2Si2O7 and (Sc 0.5Yb0.5)2Si2O7 ceramics, no significant apatite phase was detected. However, a large amount of apatite phases was observed in the CMAS residual zone of (Er 0.5Yb0.5)2Si2O7 ceramics. Furthermore, it is probable that (Sc0.5Yb0.5)2Si2O7 has the smallest average RE-O bond length, leading to the highest resistance to CMAS dissolution, which is approximately 4.6 times higher than that of Yb2Si2O7, and 5.5 times higher than that of (Er 0.5Yb0.5)2Si2O7. These findings may provide insights into the modification of CMAS corrosion resistance after doping of Sc or Er elements into the Yb 2Si2O7 matrix lattice, and lay the foundation for designing high-entropy EBCs with superior CMAS resistance.