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连续旋转化学气相浸渗是在CVI原理基础上发展的一种快速制备C/C复合材料的新工艺。通过底部发热体加热使石墨衬底及缠绕其上的二维C布获得了具有低、中、高三个温度区域的合理温度场 ,使微观孔隙与宏观孔隙分别在不同的温度区进行致密化。在沉积过程中反应物气体渗入的深度仅为一层 (或几层 )C布 ,突破了一般CVI法中“瓶颈”效应对沉积温度的制约 ,使沉积速度显著提高。通过实验研究了沉积温度、反应物气体中C3H6 浓度和衬底旋转线速度等对沉积速度的影响 ,以及反应物气体在反应区的停留时间与沉积温度对C3H6 转化率的影响。
Continuous rotation Chemical vapor infiltration is a new technology for rapid preparation of C / C composites based on the CVI principle. By heating the bottom heating element, the graphite substrate and the two-dimensional C cloth wrapped on it were obtained a reasonable temperature field with low, medium and high temperature regions, so that the microscopic pores and macropores were densified in different temperature regions respectively. During the deposition process, the depth of reactant gas infiltration is only one layer (or several layers) of C cloth, which breaks through the restriction of the “bottleneck” effect in the general CVI method to the deposition temperature and significantly increases the deposition rate. The effects of deposition temperature, concentration of C3H6 in reactant gas and substrate rotational velocity on the deposition rate and the residence time of reactant gas in the reaction zone and the deposition temperature on the conversion of C3H6 were investigated experimentally.