Fabrication process and growth mechanism of novel micro‐stack PyC interphase with different textures

Abstract Pyrolytic carbon (PyC) interphase plays a crucial role in the mechanical properties of fiber‐reinforced ceramic matrix composites. In this research, a novel micro‐stack PyC interphase with different PyC textures was designed and fabricated by changing the deposition parameters during the chemical vapor infiltration process. The growth mechanism of the micro‐stack PyC interphase with different texture were also studied by experimental characterizations and kinetic calculations, and the results show that the content ratio of (C 2 H 2 + C 2 H 4 ) to C 6 H 6 gas intermediate is a key parameter to control the texture types of PyC interphase. Furthermore, the value of orientation angle (OA) value, thickness, and modulus of the micro‐stack PyC interphase were further characterized by high resolution TEM (HRTEM), scanning electronic microscopy, and nanoindentation. Finally, the tensile testing of mini‐C f /PyC/SiC composites was conducted, and the results showed that the tensile strength of mini‐C f /PyC/SiC composites with micro‐stack PyC interphase is approximately 40% higher than that containing single high texture PyC interphase. The improvements on the tensile strength of C f /PyC/SiC composites prove the significant advantages of micro‐stack PyC interphase.