@article{Zou2025, 
author = {Lanxin Zou and Yuxian Cheng and Shijun Meng and Lei Guo},
title = {Construction of a molten CMAS-resistant bilayer-structured apatite layer used for thermal barrier coatings},
year = {2025},
journal = {Journal of Advanced Ceramics},
volume = {14},
number = {11},
pages = {9221173},
keywords = {thermal barrier coatings (TBCs), GdPO4, bilayer-structured apatite layer, CMAS wetting, calcium–magnesium–alumina–silicate (CMAS) resistance},
url = {https://www.sciopen.com/article/10.26599/JAC.2025.9221173},
doi = {10.26599/JAC.2025.9221173},
abstract = {Molten calcium–magnesium–alumina–silicate (CMAS) is easy to wet and penetrates into thermal barrier coatings (TBCs), causing coating corrosion and premature failure. The application of a protective layer on the TBC surface is considered a useful method to alleviate CMAS attack. In this study, a bilayer-structured apatite layer was developed, on which molten CMAS has low wettability. It had an acicular upper layer and a compact lower layer, which was constructed by pre-reacting GdPO4 with CMAS powders through precise regulation of the pre-reaction temperature, time, and CMAS concentration. The microstructure integrity of the bilayer-structured apatite layer remained intact after heat treatment at 1250 °C for 50 h, and the layer did not crack after 100 thermal cycles. When exposed to CMAS at 1250 °C for 20 h, the layer retained an intact structure and still functioned to prevent CMAS penetration. At 1250 °C for 30 min, the CMAS contact angle on the bilayer-structured apatite layer was 17.4°, which was three times greater than that on Gd2Zr2O7, which is another promising CMAS-resistant TBC material. Hence, the bilayer-structured apatite layer is quite attractive for addressing the CMAS issue of TBCs.}
}