Conventional ways of fabricating C/C composites are unable to achieve wetting in the core of the carbon fiber tow by molten pitch because a single tow has thousands of fibers. Pitch stabilization after infiltration into the carbon fiber preform results in local oozing of the pitch and a non-uniform microstructure due to non-uniform pitch stabilization in the preform. The objective of this research was to devise a method by which complete wetting of fibers in the tow with mesophase pitch is attained by mixing stabilized pitch and chopped and scattered carbon fibers, followed by hot-pressing and carbonization. The influence of process parameters on the carbon yield of the stabilized mesophase pitch is evaluated. The carbon yield divided by processing time and the carbon yield multiplied by the ratio of the apparent density to real density of the C/C composites are used to optimize process parameters. Results show that complete wetting of fibers with mesophase pitch is attained by this method. The carbon yield of the stabilized mesophase pitch decreases with heating rate and the mass ratio of stabilized pitch to carbon fibers, and increases with hot-pressing pressure. At high pressures and high mass ratios, local oozing of the stabilized pitch occurs. The optimum C/C composite was prepared under a hot-pressing pressure of 15 MPa, a heating rate of 0.2 °C/min and a mass ratio of stabilized pitch to carbon fibers of 1:1.

制造C / C复合材料的常规方法无法通过熔融沥青在碳纤维丝束的芯部实现润湿，因为单个丝束具有数千根纤维。渗透到碳纤维预成型坯中后的沥青稳定化会导致沥青的局部渗出和由于预成型坯中不均匀的沥青稳定化而导致的不均匀的微观结构。这项研究的目的是设计一种方法，通过将稳定的沥青与切碎和散布的碳纤维混合，然后进行热压和碳化，从而使纤维在中间相沥青中完全润湿。评估了工艺参数对稳定的中间相沥青的碳收率的影响。碳产率除以加工时间，碳产率乘以C / C复合材料的表观密度与实际密度之比可用于优化工艺参数。结果表明，通过该方法可以完全润湿具有中间相沥青的纤维。稳定的中间相沥青的碳收率随加热速率和稳定沥青与碳纤维的质量比而降低，并随热压压力而增加。在高压和高质量比下，会发生稳定沥青的局部渗出。最佳的C / C复合材料是在15 MPa的热压压力，0.2°C / min的加热速率和稳定沥青与碳纤维的质量比为1：1的条件下制备的。结果表明，通过该方法可以完全润湿具有中间相沥青的纤维。稳定的中间相沥青的碳收率随加热速率和稳定沥青与碳纤维的质量比而降低，并随热压压力而增加。在高压和高质量比下，会发生稳定沥青的局部渗出。最佳的C / C复合材料是在15 MPa的热压压力，0.2°C / min的加热速率和稳定沥青与碳纤维的质量比为1：1的条件下制备的。结果表明，通过该方法可以完全润湿具有中间相沥青的纤维。稳定的中间相沥青的碳收率随加热速率和稳定沥青与碳纤维的质量比而降低，并随热压压力而增加。在高压和高质量比下，会发生稳定沥青的局部渗出。最佳的C / C复合材料是在15 MPa的热压压力，0.2°C / min的加热速率和稳定沥青与碳纤维的质量比为1：1的条件下制备的。