根据热梯度化学气相渗透(CVI)工艺制备C/C复合材料的特点,建立了均相与非均相反应的多场耦合数学模型。以2D炭毡为预制体,天然气为前驱体,炉压为100 kPa的工艺条件下,通过计算获得了预制体致密化过程中密度的演变规律;分析了沉积温度及气体流量对致密化的影响,获得了合理的沉积温度和气体流量范围。致密化100 h后,预制体整体密度的计算值与实验值基本一致,径向密度分布的模拟值与实验值呈相同的变化规律,验证了模型的可靠性和模拟的预测能力。
A homogeneous and heterogeneous reaction mathematical model of multi-field coupling was developed according to the characteristics of thermal gradient chemical vapor infiltration(CVI) fabricating C/C composites,using 2D carbon felt as the preform,natural gas as the carbon source gas,the furnace pressure of 100kPa.The time evolution of the preform density was obtained by calculation,the effects of deposition temperatures and gas flow rates on the densification process were analyzed,and the reasonable range of deposition temperature and gas flow rate were obtained.After the preform being infiltrated for 100h,the overall and radial-direction densities of the preform from simulation agree well with those from experiment.The model is validated to reliable and the simulation has capability of forecasting the process.