Oxidation behavior of 3D SiCf/SiBCN composites at 800–1200 °C

• Published in: Journal of the European Ceramic Society Vol. 41; no. 1; pp. 148 - 157
• Main Authors: Xu, Haiming, Peng, Yuqing, Wei, Zihan, Wang, Mengqian, Li, Aijun, Shuai, Sansan, Luan, Xingang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: Mechanical properties; Oxidation; Self-healing; SiCf/BN–SiC/SiBCN; Mechanical properties; SiCf/BN–SiC/SiBCN; Oxidation; Self-healing
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2020.08.057

•3D4d SiC preform reinforced SiBCN matrix composites was fabricated and their oxidation behavior at 800−1200 ℃ for 50 h was investigated.•The SiC fiber could be protected by SiBCN matrix after oxidation treatment at temperature above.•The fracture mode of 3D SiCf/BN-SiC/SiBCN composites after exposure to air at 800−1200 ℃ for 50 h showed brittle fracture due to strong bonding fiber/matrix after oxidation treatment 3D SiCf/BN–SiC/SiBCN composites were fabricated via precursor impregnation and polymer infiltration pyrolysis (PIP). Oxidation behavior of the composites heated in air at 800 °C, 1000 °C and 1200 °C for 50 h was investigated. Following the oxidation treatment, it was found that the bending strength of the composites at different oxidation temperatures was degraded. The weight loss of the composites decreased gradually over the range of oxidation times of 1–50 h. In order to clarify the oxidation mechanism of the composites, reconstructed images, microstructures, phase compositions, the oxide layer formed on the composites and main chemical reactions were all analyzed. It was revealed that the degradation in the fracture strength of the composites was closely related to the oxidation of SiBCN matrix and BN-SiC interphase, whereas there was no signs of oxidation products about SiC fiber, which indicated that SiC fiber could be protected from oxygen by SiBCN matrix at 800−1200 °C in air.