三维织造预制体微观结构及致密化  

Microstructure and densification of 3D weaving preform

作　　者：黄成杰 杨敏[1] 李红[1] 任慕苏[1] 孙晋良[1] HUANG Cheng-jie;YANG Min;LI Hong;REN Mu-su;SUN Jin-liang(Composite Research Center of Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学复合材料研究中心,上海200444

出　　处：《材料工程》2021年第1期104-111,共8页Journal of Materials Engineering

基　　金：军委科技委基础加强计划重点基础研究项目(2017-JCJQ-ZQ-035);上海市教育发展基金会和上海市教育委员会“曙光计划”(18SG34)。

摘　　要：碳纤维预制体是碳/碳材料的骨架,致密化过程中,基体碳填充预制体孔隙形成碳/碳复合材料。为探索碳纤维预制体微观结构与致密化的关系,以3种三维织造预制体为研究对象,通过金相显微镜观察预制体微观结构,建立预制体理论结构数字化模型,计算对比孔隙率情况后获得预制体中不同类型孔隙的体积含量,研究孔隙结构对化学气相沉积致密化效率的影响。研究结果表明:三维织造预制体中孔隙呈周期性重复排列,XY向纤维层间距、Z向纤维间距越小,预制体中纤维体积含量越高;预制体中孔隙主要由纤维束内孔隙和X,Y,Z向纤维束包围的束间孔隙构成;预制体中的孔隙大小和分布影响致密化效率,孔隙率高的预制体在致密化前期增密速率快,孔隙结构均匀的预制体在致密化后期增密速率快。The carbon fiber preform is the skeleton of the carbon/carbon material.During the densification process,the pores of the preform is filled by the matrix carbon to form a carbon/carbon composite material.In order to explore the relationship between the microstructure of carbon fiber preform and densification,three kinds of three-dimensional woven preforms were used as the research objects.The microstructure of the preform was observed through a metallurgical microscope,and digital models of the theoretical structure of the preforms were established to calculate the volume content of different types of pores in the body,and to study the effect of pore structure on the densification efficiency of chemical vapor deposition.The results show that the pores in the three-dimensional woven preform are periodically and repeatedly arranged.The fiber volume fraction in the preform is related to the XY fiber layer spacing and the Z direction fiber spacing,the smaller the XY fiber layer spacing and the Z direction fiber spacing are,the higher the fiber volume content of the preform is;the preform is mainly composed of the pores in the fiber bundle and the inter-bundle pores surrounded by the X,Y,Z fiber bundles;the pore size and structure of the preform affect the densification efficiency,and the densification rate of the preform with high porosity is higher in the.early stage of densification,and the preform with uniform pore structure gains weight quickly in the later stage of densification.

关 键 词：碳纤维预制体 孔隙结构 孔隙率 CVI致密化 结构模型 

分 类 号：TB332[一般工业技术—材料科学与工程]