@article{Peng2025, 
author = {Kexue Peng and Ying Qiao and Qian Li and Xinxin Cao and Long Wang and Guifang Han and Jianzhang Li and Jingyu Qin and Jingde Zhang},
title = {Gradient tri-layered TGOs in MoSi2/HfO2 duplex EBCs for effective protection of SiC substrate against steam corrosion at 1500 °C for 200 h},
year = {2025},
journal = {Journal of Advanced Ceramics},
volume = {14},
number = {7},
pages = {9221101},
keywords = {environmental barrier coatings (EBCs), tri-layered thermally grown oxides (TGOs), MoSi2/HfO2 duplex EBCs, steam corrosion resistance, SiC-based composites},
url = {https://www.sciopen.com/article/10.26599/JAC.2025.9221101},
doi = {10.26599/JAC.2025.9221101},
abstract = {The protective effectiveness of environmental barrier coatings (EBCs) for SiC-based composites is limited by the thickening and phase transformation of the SiO2 scale, known as thermally grown oxide (TGO). In this study, a tri-layered TGO scale, comprising cristobalite, Hf-doped SiO2 glass, and particle-reinforced Hf–Si–O glass, was formed during the oxidation of MoSi2/HfO2 duplex EBCs. The incorporation of gradient Hf doping and HfO2/HfSiO4 particle reinforcement effectively suppressed the crystallization and phase transition of SiO2 and mitigated the internal stress within the EBCs, generating a crack-blocking effect. This effect prevented the scale of the TGOs from further channel crack propagation, enabling the SiC substrate with no detectable corrosion after 200 h of exposure at 1500 °C in steam, even when the TGOs thickness reached 24.5 μm. This work presents a novel strategy to simultaneously extend the service lifetime and enhance the high-temperature capability of EBCs through the tailored design of TGO composition and structure.}
}