Process Control of PyC Interphases Microstructure and Uniformity in Carbon Fiber Cloth

The mechanical properties of ceramic matrix composites are highly dependent on the microstructure and interphase homogeneity.This study examined the influence of process factors, such as temperature, propylene partial pressure, retention time, and hydrogen partial pressure, on the microstructure and homogeneity of PyC interphase deposited on the surface of carbon fiber cloth.Various characterization techniques, including SEM, TEM, and other methods, were used to characterize the microstructure and texture of the PyC interphase.The results show that increasing temperature and propylene partial pressure lead to a more regular texture in the interphase, while decreasing hydrogen partial pressure has the opposite effect, and retention time has little effects.Additionally, an increase in temperature and propylene partial pressure leads to an uneven distribution of interphase thickness, and overhigh propylene partial pressure directly leads to the production of carbon black.Increasing retention time helps to improve interphase homogeneity.The interphase uniformity of medium and high textures firstly drops and then increases when the hydrogen partial pressure increases, but the interphase uniformity of low textures is less impacted.In the end, the development method of PyC interphase was clarified, the influence of process parameters on the growth mechanism of PyC interphase was revealed, and the influence on the formation principle and interphase uniformity was further investigated.