【摘要】 采用活性碳纤维转换法制备了壳核结构SiC/C纤维,采用拉曼光谱、SEM、XRD以及热重分析等测试方法对比研究了生成SiC的厚度对壳核结构SiC/C纤维样品的热重及吸波性能的影响。结果表明:包裹SiC壳层后样品吸波性能得到提高,样品厚度为3.0 mm时,保温4 h样品的最小反射损耗在8.24 GHz处达到-17.22 dB,低于-10 dB(90%的电磁波被吸收)的频宽在2.0 mm处达到4.8 GHz(11.12～15.92 GHz);保温3 h样品的最小反射损耗在8.23 GHz处达到-14.45 dB,低于-10 dB(90%的电磁波被吸收)的频宽在2.0 mm处达到4.56 GHz(10.88～15.44 GHz);且随着SiC含量的升高,试样微波吸收性能有所增强;制备的壳核结构SiC/C纤维样品起始氧化温度提高了150℃以上,并且最终残余质量在50%左右,即包裹SiC纤维后样品的抗氧化能力大大提高。更多还原

【Abstract】 SiC/C fibers with shell core structure were prepared by activated carbon fiber conversion method. The effects of SiC thickness on thermogravimetry and microwave absorption property of SiC/C fibers with shell core structure were studied by Raman spectroscopy, SEM, XRD and thermogravimetric analysis. The results show that the microwave absorbing property of the samples coated with SiC shell are improved. When the thickness of the sample is 3.0 mm, the minimum reflection loss of the sample after holding for 4 h reaches-17.22 dB at 8.24 GHz, and the frequency bandwidth less than-10 dB(90% of electromagnetic wave is absorbed) reaches 4.8 GHz(11.12 GHz to 15.92 GHz) at 2.0 mm. The minimum reflection loss of the sample kept for 3 h reaches-14.45 dB at 8.23 GHz, which is lower than-10 dB(90% of electromagnetic wave is absorped) bandwidth reaches 4.56 GHz at 2.0 mm(10.88 GHz to 15.44 GHz). With the increase of SiC content, the microwave absorption property of the samples are enhanced. The initial oxidation temperature of SiC/C fiber samples with core-shell structure is increased by more than 150 ℃, and the final residual mass is about 50%. That is to say, the oxidation resistance of the samples coated with SiC fibers is greatly improved.更多还原