This study presents a cost-effective wet chemical coating process for fabricating a boron nitride (BN) interphase on silicon carbide (SiC) fibers, increasing the oxidation resistance and performance of SiCf/SiC ceramic matrix composites. Using urea as a precursor, optimal nitriding conditions were determined by adjusting the composition, concentration, and immersion time. X-ray diffraction analysis revealed distinct BN phase formation at 1300°C and 1500°C, while a mixture of BN and B2O3 was observed at 1200°C. HF treatment improved coating uniformity by removing SiO2 layers formed during the de-sizing process. Optimization of the boric acid-to-urea molar ratio resulted in a uniform, 130-nm-thick BN layer. This study demonstrates that the wet coating process offers a viable and economical alternative to chemical vapor deposition for fabricating high-performance BN interphases in SiCf/SiC composites that are suitable for high-temperature applications.

1. Introduction 
2. Experimental Section 
3. Results and Discussion 
4. Conclusion 
Funding
Conflict of Interest 
Data Availability Statement 
Author Information and Contribution 
Acknowledgement
References

• 김경호(한국세라믹기술원 이천분원) | Kyung Ho Kim (Korea Institute of Ceramic Engineering and Technology (Icheon), Gyeonggi-do 17303, Republic of Korea)
• 한윤수(한국세라믹기술원 이천분원) | Yoonsoo Han (Korea Institute of Ceramic Engineering and Technology (Icheon), Gyeonggi-do 17303, Republic of Korea) Corresponding author