Effect of SiC nanowires on the mechanical properties and thermal conductivity of 3D-SiCf/SiC composites prepared via precursor infiltration pyrolysis

• Published in: Journal of the European Ceramic Society Vol. 41; no. 10; pp. 5026 - 5035
• Main Authors: Cui, Guang-Yuan, Luo, Rui-Ying, Wang, Lian-Yi, Huang, Peng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2021
• Subjects: Acoustic emission; Conductivity; Mechanical properties; SiC nanowires; SiCf/SiC composites; Thermal; Mechanical properties; Conductivity; Acoustic emission; SiCf/SiC composites; SiC nanowires; Thermal
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.04.003

•A new interface structure of PyC+SiCNWS was prepared on the surface of SiC fiber.•The damage evolution process of SiCf/SiC was analysed by acoustic emission.•The mechanism of influence of SiCNWS on the thermal conductivity of 3D-SiCf/SiC composites was analysed. In this study, SiC nanowires (SiCNWS) were grown in situ on the surface of PyC interface through chemical vapor infiltration (CVI) to improve the mechanical characteristics and thermal conductivity of three-dimensional SiCf/SiC composites fabricated via precursor infiltration pyrolysis (PIP). The effect of SiCNWS on the properties of the obtained composites was investigated by comparing them with conventional SiCf/PyC/SiC composites. After the deposition of SiCNWS, the flexural strength of the SiCf/SiC composites was found to increase by 46 %, and the thermal conductivity showed an obvious increase at 25−1000 °C. The energy release of the composites in the damage evolution process was analysed by acoustic emission. The results indicated that the damage evolution process was delayed owing to the decrease in porosity, the crack deflection and bridging of the SiCNWS. Furthermore, the excellent thermal conductivity was attributed to the thermally conductive pathways formed by the SiCNWS in the dense structure.