C/C复合材料TCVI工艺温度控制系统研究

本文简要介绍了C C复合材料TVCI工艺 (热梯度化学气相渗透 )原理 ,分析了其温度控制特点。针对该工艺高精度温度与温度梯度难以控制的不足 ,引入模糊控制理论 ,建立了基于自寻优的TCVI工艺温度模糊控制系统。仿真结果表明 ,该控制系统稳态精度高 ,规则易于调整 。

基于串行通讯的TCVI工艺集散控制研究与应用

TCVI(热梯度CVI)工艺是制备C C复合材料的一种重要工艺。本文在分析TCVI工艺流程的基础上,利用集散控制的思想,设计一种基于串行通讯的TCVI工艺简单集散控制系统,利用VisualBasic的MSComm通讯控件实现上下位机的通信,采用VB和组态王开发TCVI工艺监控系统,实现了该工艺的自动控制,并利用此系统制备出密度大于1.75g cm3、均匀性较好的C C复合材料制件。

Multi-physical field coupling simulation of TCVI process for preparing carbon/carbon composites

To prepare Carbon/Carbon (C/C) composites with advanced performance, the thermal gradient chemical vapor infiltration (TCVI) process has been optimized by simulation. A 2D axisymmetric unstable model was built, which included convection, conduction, diffusion, densification reactions in the pores and the evolution of the porous medium. The multi-physical field coupling model was solved by finite element method (FEM) and iterative calculation. The time evolution of the fluid, temperature and preform density field were obtained by the calculation. It is indicated that convection strongly affects the temperature field. For the preform of carbon/carbon composites infiltrated for 100 h by TCVI, the radial average densities from simulation agrees well with those from experiment. The model is validated to be reliable and the simulation has capability of forecasting the process.

C/C复合材料热梯度CVI工艺监控系统的实现

热梯度CVI工艺(TCVI)是制备C/C复合材料的一种高效工艺。该工艺致密化机理比较复杂,影响控制效果的因素较多,实现自动化监控较为困难。本文在分析TCVI工艺流程的基础上,提出了沉积工艺控制方案,并利用工业控制组态软件K ingview 6.5开发了TCVI工艺监控系统,可以实现对工艺过程的自动控制。

C/C复合材料热梯度CVI工艺的数值模拟研究

TCVI(热梯度 CVI)工艺是一种很有潜力的 C/C复合材料制备工艺 ,它可以在较短的时间内制备出密度均匀性较高的 C/C复合材料制件。本文根据传热、传质理论及 C/C复合材料预制体的结构特点建立了 TCVI过程的动力学模型和几何模型 ,在该模型的基础上利用数值模拟技术对该工艺进行了模拟和分析。模拟结果为 TCVI工艺的开发和应用提供了理论依据。