预制体结构对SiC_(f)/SiC复合材料力学和热性能的影响  

Effect of preform structure on mechanical and thermal properties of SiC_(f)/SiC composites

作　　者：王徐辉 吴宗绪 陈招科 伍艳 熊翔 WANG Xu-hui;WU Zong-xu;CHEN Zhao-ke;WU Yan;XIONG Xiang(Science and Technology on High Strength Structural Materials Laboratory,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]Science and Technology on High Strength Structural Materials Laboratory,Central South University,Changsha 410083,China [2]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2024年第1期101-113,共13页中南大学学报（英文版）

基　　金：Project(6142907200301) supported by the National Defense Pre-Research Foundation of China;Project supported by the Key Laboratory for Lightweight High Strength Structural Materials,Central South University,China。

摘　　要：本文采用化学气相渗透法制备了具有二维多层、三维角联锁机织和多轴三维编织三种预制体结构的SiC_(f)/SiC复合材料。在综合分析纤维排列、SiC基体和孔隙分布的基础上,详细讨论了预制体结构对SiC_(f)/SiC复合材料力学性能和热性能的影响。结果表明,复合材料的力学性能和热导率受纤维排列方式和复合材料密度的综合影响,而热膨胀系数主要受纤维排列方式的影响。此外,二维多层复合材料、三维角联锁机织复合材料和多轴三维编织复合材料的热导率可以分别用串联模型和平行模型来解释。多轴三维编织复合材料由于内部具有连续的可以作为热流快速通道的三维网状SiC基体层,因此具有较高的室温热导率。而随着温度的升高,SiC声子间的散射逐渐增强,SiC基体层在多轴三维编织复合材料中作为声子传播快速通道的作用逐渐减弱,热导率随温度降低的趋势更明显。In this paper,SiC_(f)/SiC composites with three kinds of preform structures,namely 2D multilayered,3D angleinterlock and multiaxis 3D braided,were prepared by chemical vapor infiltration.The influences of preform structure on mechanical and thermal properties of SiC_(f)/SiC composites were discussed in detail,on the basis of comprehensive analyses of fiber arrangement,SiC matrix and pore distribution,and so on.The results show that the mechanical properties and thermal conductivity are comprehensively affected by the fiber arrangement and the density of composites,while the coefficient of thermal expansion is mainly influenced by the fiber arrangement.In addition,the thermal conductivity of 2D multilayered,3D angle-interlock and multiaxis 3D braided composites could be explained by series model and parallel model,respectively.The continuous three-dimensional network structure of SiC matrix layer inside multiaxis 3D braided composites could be regarded as a fast channel for heat flow,resulting in a higher thermal conductivity.As the temperature increases,the scattering between phonons gradually increases and becomes the main factor affecting the thermal conductivity.In this case,the role of the SiC matrix layer as a fast channel for phonon propagation in multiaxis 3D braided composites gradually weakens.

关 键 词：预制体结构 抗弯强度 热导率 热膨胀系数 SiC_(f)/SiC复合材料 

分 类 号：TU756.4[建筑科学—建筑技术科学]