Modeling of an improved Chemical Vapor infiltration Process for Ceramic Composites Fabrication
Modeling of an improved Chemical Vapor infiltration Process for Ceramic Composites Fabrication
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DOI：
10.1111/j.1151-2916.1990.tb09785.x
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发表时间：
1990-06
影响因子：
3.9
通讯作者：
N. Tai;T. Chou
中科院分区：
文献类型：
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作者：
N. Tai;T. Chou
采用准稳态方法模拟了压力驱动、温度梯度化学气相渗透（改进的CVI工艺）制备陶瓷基复合材料的过程。在这项研究中的沉积基体是SiC，这是从甲基三氯硅烷气体在过量的氢气下的热分解转化。采用三维单胞模型来模拟非连续纤维毡和三维机织物中增强体的空间排列。本文的目的是预测（1）加工过程中纤维预制件中的温度和密度分布，（2）凝固前沿的推进，（3）总的制造周期，以及（4）保持恒定流速的蒸汽入口压力变化。此外，还研究了边界温度和入口压力变化对总推进时间的影响。本文研究的制备温度范围为873 ~ 1473 K，压力范围为1.0001 ~ 2.0000atm（1.0134 × 10 ~ 5 ~ 2.0265 × 105 Pa）。基于这种分析，可以量化反应器条件对CVI工艺中最终产品密度的影响。
A quasi-steady-state approach is applied to model the pressure-driven, temperature-gradient chemical vapor infiltration (improved CVI process) for ceramic matrix composites fabrication. The deposited matrix in this study is SiC which is converted from the thermal decomposition of methyltrichlorosilane gas under excess hydrogen. A three-dimensional unit cell is adopted to simulate the spatial arrangements of reinforcements in discontinuous fiber mats and three-dimensionally woven fabrics. The objectives of this paper are to predict (1) the temperature and density distributions in a fibrous preform during processing, (2) the advancement of the solidified front, (3) the total fabrication period, and (4) the vapor inlet pressure variation for maintaining a constant flow rate. Furthermore, the effect of boundary temperature and inlet pressure variations on the total proassing period is also studied. The fabrication temperature examined in this paper is in the range between 873 and 1473 K, and the pressure is from 1.0001 to 2.0000 atm (1.0134 × 105 to 2.0265 × 105 Pa). Based upon this analysis, the influence of the reactor condition on the density of the final product in a CVI process can be quantified.