Thermal expansion behavior of carbon fiber reinforced chemical-vapor-infiltrated silicon carbide composites from room temperature to 1400 °C

Thermal expansion behavior of C/SiC composites with three different preform architectures from room temperature (RT) to 1400 °C was investigated. It was found that they related to changes of interfacial thermal stress and microstructure due to interaction of fibers and matrix. The longitudinal coefficients of thermal expansion (CTE) of 1D and 3D C/SiC composites and in-plane CTE of 2D C/SiC composites changed in such similar way that increasing linearly with increasing temperature, reaching maximum values at about 900 °C, and fluctuating from 900 to 1400 °C. However, they had different increasing rates below 900 °C. In addition, transverse CTEs of 1D and 3D C/SiC increased linearly and both changed in a similar way as bulk CVD SiC material at low temperature range. And then, they increased rapidly from 1200 to 1400 °C after a decrease at 900 °C.