无机材料学报 ›› 2014, Vol. 29 ›› Issue (9): 1003-1008.DOI: 10.15541/jim20140165 CSTR: 32189.14.10.15541/jim20140165

• • 上一篇    

碳纤维复合Si3N4陶瓷材料的制备及性能研究

王贺云1,2, 刘 茜1, 周 遥1,2, 周真真1,刘光辉1   

  1. (1. 中国科学院 上海硅酸盐研究所, 高性能陶瓷和超微结构国家重点实验室, 上海 200050; 2. 中国科学院大学, 北京100049)
  • 收稿日期:2014-04-02 出版日期:2014-09-17 网络出版日期:2014-08-21

Preparation and Properties of Carbon Fiber/Si3N4 Composites

WANG He-Yun1,2, LIU Qian1, ZHOU Yao1,2, ZHOU Zhen-Zhen1, LIU Guang-Hui1   

  1. (1. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China)
  • Received:2014-04-02 Published:2014-09-17 Online:2014-08-21
  • Supported by:
    Foundation item: Science and Technology Committee of Shanghai Municipal Government (11JC1413600)

摘要:

为研究碳纤维(Cf)加入量对复合材料性能的影响, 本研究以Y2O3为烧结助剂, 采用热压烧结技术制备了Cf/Si3N4复合材料, 其中碳纤维加入量为0、2wt%和5wt%。选用乙醇作分散介质,通过球磨工艺可有效分散短切碳纤维。研究结果表明: 碳纤维在复合材料中分散均匀, 且材料中的晶粒在垂直于热压压力的方向呈现一定取向排列。高温烧结过程中, 碳纤维与Si3N4或其表面的SiO2层发生反应, 生成SiC中间层。适量碳纤维加入有助于提高复合材料的热导性能。当Cf加入量为2wt%时,Cf/Si3N4的热导率较高, 为45.8 W/(m?K);而不添加Cf的样品, 其热导率为37.1 W/(m?K)。加入Cf后, Cf/Si3N4的断裂韧性有小幅提高, 维氏硬度在16.6~16.8 GPa范围内变化。

关键词: Cf/Si3N4复合材料, 热压烧结, 界面反应, 热导, 力学性能

Abstract:

To investigate the effects of carbon fiber (Cf) adding content on the properties of Si3N4, Cf/Si3N4 composites with 0, 2wt% and 5wt% of short carbon fibers were prepared by hot-press sintering method, using Y2O3 as sintering additives. With long-time ball milling process, carbon fibers were well dispersed in mixed powders using ethanol as dispersion medium. Carbon fibers distribute uniformly in the composites and Si3N4 grains grow to a certain degree in the vertical direction to the pressure of hot-press. The interfacial by-product silicon carbide (SiC) phase forms due to the reaction between added Cf and Si3N4 particles or SiO2 layer on surface of Si3N4 particles during high temperature sintering. The sample with 2wt% Cf addition achieves a higher value of thermal conductivity (45.8 W/(m?K)), while the thermal conductivity of Si3N4 without Cf is only 37.1 W/(m?K). Therefore, the addition of Cf can improve the thermal conductivity of the composites. The fracture toughness of the composites has a slight increase with Cf adding. The measured hardness values for all samples are within a range of 16.6-16.8 GPa.

Key words: Cf/Si3N4 composite, hot-press sintering, interfacial reaction, thermal conductivity, mechanical property