| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Corrosion and Environmental Degradation: Theory and Practice
|
| Presentation Title |
Thermal Properties and CMAS Corrosion Resistance of Rare Earth Phosphates as Environmental Barrier Coatings for SiC-based Ceramic-Matrix Composites |
| Author(s) |
Bishnu Pada Majee, Keith Bryce, Liping Huang, Jie Lian |
| On-Site Speaker (Planned) |
Bishnu Pada Majee |
| Abstract Scope |
Single component REPO4 (RE=Sc, Lu, Yb, Er & Y) and multicomponent (Sc0.2Lu0.2Yb0.2Er0.2Y0.2)PO4 rare earth phosphates were synthesized to investigate their potential application as environmental barrier coatings (EBCs). They were prepared via chemical route and characterized by X-ray diffraction, dilatometry, laser flash technique, and scanning electron microscope. Prepared Xenotime phosphates show average CTE value in the range of 5.5 to 7 × 10-6 °C-1, close to that of SiC-based CMC substrate (~4.5-5.5 × 10-6 °C-1). The multicomponent rare earth phosphate showed low thermal conductivity (~2.6 W m-1 °C-1 at 1000 °C) compared to the single-component rare earth phosphate due to mass and size disorder. CMAS corrosion tests were conducted at 1300 °C for 5, 45, and 96 hours, where a continuous and dense reaction layer primarily composed of Ca8MgRE(PO4)7 formed and grew in thickness with time. The CMAS-(Sc0.2Lu0.2Yb0.2Er0.2Y0.2)PO4 interaction at 1300 °C exhibited a thinner reaction layer than REPO4-CMAS interactions. |