炭素技术

前驱体浸渍裂解(Precursor Impregnation Pyrolysis, PIP)是C_f/SiC复合材料制备及基体致密化的关键技术，其致密化效果直接决定复合材料的最终力学性能。本研究首先利用气-液两相流模型，在宏观尺度上模拟炭纤维预制体在PIP工艺中的浸渗过程；其次，通过固体传热模型，同样在宏观尺度上模拟预制体的固化和裂解阶段，基于此建立涵盖这3个阶段的密度模型。深入研究纤维预制体的多周期孔隙信息传递机制，以此为基础构建了C_f/SiC陶瓷基复合材料的多周期致密化模型；最终，将模型预测密度与实际PIP工艺产品的密度进行对比。结果显示，模型平均误差为5.90%,最大误差不超过6.76%,充分验证了模型的准确性和可靠性。该模型不仅具有理论意义，更在实际应用中展现出重要价值，为C_f/SiC复合材料的制备和优化提供了有力支持。

Precursor impregnation pyrolysis(PIP) is an important technology to prepare C_f/SiC composites and achieve matrix densification, which is directly related to the mechanical properties of the ultimate product.This study initially employs a gas-liquid two-phase flow model to simulate the impregnation process of carbon fiber preforms during the PIP process on a macroscopic scale.Subsequently, solid heat transfer model is utilized to simulate the curing and pyrolysis phases of the preforms, also on a macroscopic scale.Based on these simulations, the density model that encompasses all three aforementioned phases is established.This study delves into the multi-cycle pore information transfer mechanism of fiber preforms, and based on this, constructs a multi-cycle densification model for C_f/SiC ceramic matrix composites.Ultimately, the predicted density from the model is compared with the actual density of products obtained from the PIP process.The results show that the model exhibits an average error of 5.90%,with the maximum deviation not exceeding 6.76%.This fully corroborates the model's accuracy and reliability.The model is not only theoretically significant but also demonstrates substantial value in practical applications, providing robust support for the fabrication and optimization of C_f/SiC composites.