ICVI法制备Si_3N_(4P)/Si_3N_4复合材料致密化行为数值模拟  

Numerical simulation for ICVI process of Si_3N_(4P)/Si_3N_4 composites

作　　者：胡卓沛[1] 成来飞[1] 魏玺[1] 赵春年[1] 刘谊[1] 

机构地区：[1]西北工业大学超高温结构复合材料国防科技重点实验室,西安710072

出　　处：《复合材料学报》2006年第5期111-115,共5页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金重大计划重点项目(90405015)

摘　　要：根据Si3N4颗粒增强体的结构特点及等温化学气相法(ICVI)的工艺特点,对Si3N4颗粒增强Si3N4复合材料的致密化过程进行了数值模拟。用球形孔隙模型表征Si3N4颗粒增强体的结构特征,用传质连续方程表征先驱体在预制体中的浓度分布。为了检验模型的准确性和适用性,进行了相应的实验验证。模拟结果与实验结果具有相似的致密化规律,预测的渗透时间和孔隙率与实验结果均十分接近,表明本文中建立的数学模型可以较好地表征Si3N4P/Si3N4复合材料的ICVI过程。A mathematical model according to structural feature of Si3 N4 particle reinforcement and process characteristic of isothermal chemical vapor infiltration （ICVI） was proposed to numerically simulate the densification behaviors of Si3 N4 particle reinforced Si3N4 composites. The ball-like pore model is developed to depict the structure of Si3 N4 particle reinforcement and the mass transfer equation of reagents is used to characterize the concentration profile in the preform. The corresponding experiment was done in order to testify the mathematical model. The calculated results represent the same densification regularity as the experimental data does, and the curves of calculated infiltration time and porosity are in agreement with the experimental ones, which indicates that the model developed here is reasonable to characterize the ICVI process of Si3 N4p/Si3 N4 composites.

关 键 词：Si3N4/Si3N4复合材料 等温化学气相渗透 数值模拟 

分 类 号：TB332[一般工业技术—材料科学与工程]