无机材料学报

• 研究论文 • 上一篇    下一篇

“CVI+压力PIP”混合工艺制备低成本 C/SiC复合材料

闫联生1, 李贺军1, 崔红2, 王涛2   

  1. 1. 西北工业大学材料学院, 西安 710072;
    2. 西安航天复合材料研究所, 西安 710025
  • 收稿日期:2005-05-13 修回日期:2005-07-11 出版日期:2006-05-20 网络出版日期:2006-05-20

Low-cost C/SiC Composites Prepared by CVI+Pressure-PIP Hybrid Process

YAN Lian-Sheng1, LI He-Jun1, CUI Hong2, WANG Tao2   

  1. 1. Material Department, Northwestern Polytechnical University, Xi'an 710072, China;
    2. Xi'an Aerospace Composite Material Institute, Xi'an 710025, China
  • Received:2005-05-13 Revised:2005-07-11 Published:2006-05-20 Online:2006-05-20

摘要: 以低成本填料改性有机硅浸渍剂作为先驱体, 采用“化学气相渗透法+压力先驱体浸渍裂解法”(CVI+ P-PIP)混合工艺制备了低成本C/SiC陶瓷复合材料. 研究了浸渍剂裂解机理, 探讨了界面
涂层对复合材料性能的影响. 结果表明, 填料改性有机硅浸渍剂裂解产物结构致密、陶瓷产率高; 压力可提高填料改性有机硅浸渍剂的致密效率. 混合工艺充分利用沉积SiC基体和裂解SiC基体的致密化特点, 有效缩短了制备周期. C/SiC/C三层界面不仅可降低纤维/基体之间结合强度界面, 提高了复合材料韧性; 而且减缓了氧化性气体扩散到碳纤维表面的速度, 改善了复合材料的抗氧化性能.
复合材料的抗弯强度达到455MPa, 断裂韧性达到15.7MPa·m-1/2. 在1300℃空气中氧化3h, 复合材料失重仅8.5%.

关键词: C/SiC复合材料, 低成本, “CVI+压力PIP”混合工艺

Abstract: Low-cost C/SiC composites were prepared by “CVI+PIP”combined process. A silicone impregnant with fillers was used in the PIP process. The pyrolysis mechanism of the impregnant and the properties of the composites were investigated. The results show that silicone impregnant with fillers has high pyrolysis yield and its pyrolysis product is dense, pressure can enhance the PIP efficiency of the fillered impregnant. “CVI+ P-PIP” hybrid process makes use of the densification advantages of CVI process and PIP process, which can shorten the process cycle. C/SiC/C multilayered coating can decrease the bonding strength of the fiber/matrix interface, and it reduces the diffusing velocity of oxygen to the surface of carbon fibers. Hence the mechanical properties and anti-oxidation properties are improved. The flexural strength and fracture toughness (K IC) of the C/SiC composites are 455MPa and 15.7MPa·m-1/2 respectively. The weight loss of the C/SiC composites is merely 8.5% after heated at 1300℃ in air 3h.

Key words: C/SiC composites, low cost, “CVI+PIP”combined process

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