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pp.664-675
Ultra-high temperature ceramics (UHTCs) exhibit extremely high melting points (> 2,500 °C) and maintain structural stability under severe conditions. However, their intrinsic brittleness and oxidation vulnerability limit their direct application in aerospace components exposed to extreme environments. To overcome these limitations, UHTC-based composites reinforced with secondary phases such as ZrO2 are required to improve fracture toughness and oxidation resistance. The polymer infiltration and pyrolysis (PIP) process provides a promising fabrication route for such composites, offering densification of porous matrices with liquid precursors while maintaining uniform microstructures. Here, we report a novel zirconia precursor (PZC-12) synthesized through a sol-gel reaction of zirconium propoxide with acrylic acid (1:2 molar ratio). The liquid precursor exhibited a suitable viscosity (~518 cP) and enabled dual crosslinking via hydroxyl condensation combined with radical polymerization of vinyl groups. Consequently, effective thermal curing was accomplished upon heating at 80 °C for 12 h. This strategy minimized premature decomposition and achieved a high ceramic yield of 52.7 %. Pyrolysis at 600 °C in air produced nanosized t-ZrO2, which transformed into m-ZrO2 with grain growth at higher temperatures. Applied in PIP, a ZrB2-ZrO2 composite was successfully fabricated, demonstrating that dual crosslinking is critical for high-yield, reliable PIP-based UHTC composites.
1. 서 론
2. 실험 방법
2.1. 시료
2.2. PZC 합성
2.3. ZrO2 제조
2.4. PIP 활용한 ZrB2-ZrO2 복합재 제조
2.5. 분석
3. 결과 및 고찰
3.1. ZrO2 전구체 합성 전략 및 특성
3.2. PZC-12의 분자 구조 분석
3.3. 온도에 따른 ZrO2 의 결정 구조 변화
3.4. ZrO2의 미세구조
3.5. PZC-12의 열적 특성 및 세라믹화 거동
3.6. PIP 공정을 이용한 ZrB2 -ZrO2 복합재 제조
4. 결 론
Acknowledgement
References
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