活性填料在先驱体转化法纤维增强陶瓷基复合材料中的应用 II——复合材料的制备及其表征

将活性填料Al应用到吉林碳纤维(JC)和M40JB纤维增强先驱体转化SiC陶瓷基复合材料的制备中。研究表明,经过7个周期的致密化处理,当复合材料素坯中不含活性填料时,JC增强复合材料比M40JB增强复合材料有更高的弯曲强度,因此,JC纤维更适合用作先驱体转化陶瓷基复合材料的增强纤维;当复合材料素坯中含有活性填料Al时,由于Al与碳纤维发生碳化反应,使纤维受损,在纤维与基体之间形成不良的界面结合,导致复合材料的强度发生退化。图象分析表明,M40JB与Al的反应层厚度约为0.94 μm。为了防止碳纤维与Al发生反应,应对碳纤维进行适当的表面处理。

APPLICATION OF ACTIVE FILLER IN PREPARATION OF FIBER REINFORCED CERAMIC MATRIX COMPOSITES BY POLYMER-INFILTRATION-PYROLYSIS Ⅱ--PREPARATION AND PERFORMANCE TEST OF COMPOSITES

Application of active filler aluminium (Al) in preparation of Jilin carbon fiber (JC) and M40JB fiber reinforced ceramic matrix composites (FRCMCs) by polymer-infiltration-pyrolysis (PIP) was investigated, respectively. The results showed that, after 7 cycles of polymer infiltration-pyrolysis, the flexural strength of the as-fabricated composites reinforced by JC was higher than that of those reinforced by M40JB when active filler was not added. Therefore, JC was more suitable for the reinforcement of FRCMCs than M40JB by PIP process. The flexural strength of the composites with active filler Al decreased drastically for the harmful interphase produced by the reaction between Al and carbon fiber, which was accordingly degenerated badly. The image analysis showed that the reaction layer between M40JB and Al was about 0.94μm. Suitable surface treatment of the carbon fiber such as coating was necessary to prevent the fiber from reacting.