Enchanced high-temperature performances of SiC/SiC composites by high densification and crystalline structure

• Published in: Composites science and technology 2011-02, Vol.71 (3), p.326-332
• Main Authors: Shimoda, Kazuya, Hinoki, Tatsuya, Kishimoto, Hirotatsu, Kohyama, Akira
• Format: Article
• Language: English
• Subjects: A. Ceramic–matrix composites (CMCs); B. High-temperature properties; B. Thermal properties; B. Thermo-mechanical properties; Cross-disciplinary physics: materials science; rheology; Crystal structure; D. Scanning/transmission electron microscopy (STEM); Densification; Exact sciences and technology; Heat transfer; Materials science; Microstructure; Other materials; Physics; Silicon carbide; Slurries; Specific materials; Tensile strength; Thermal conductivity
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2010.11.026

We report the enchanced in situ performances of tensile strength and thermal conductivity at elevated temperatures of the PCS-free SiC/SiC composite with a high fiber volume fraction above 50% fabricated by NITE process for nuclear applications. The composite was fabricated by the optimized combination of the fiber coating, the matrix slurry and the pressure-sintering conditions, based on our previous composites’ study history. The composite showed the excellent tensile strength up to 1500 °C, that it retained approximately 88% of the room-temperature strength. Also, the thermal conductivity of the composites represented over 20 W/m K up to 1500 °C, which was enough high to take the advantage of the assumed design value for nuclear applications. Microstructural observation indicated that the excellent high-temperature performances regarding tensile strength and thermal conductivity up to 1500 °C were the contribution to the high densification and crystalline structure in matrix.