SiO_2表面改性炭纤维的抗氧化性能与微波吸收性能  

Oxidation resistance and microwave absorption properties of SiO_2-modified carbon fiber

作　　者：唐益群[1] 周克省[1] 邓联文[1] 肖鹏[2] 周伟[2] 周亮[1] 罗衡[2] 洪文[2] 

机构地区：[1]中南大学物理与电子学院,长沙410083 [2]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2013年第4期615-620,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点基础研究发展规划(973计划)资助项目(2011CB605804)

摘　　要：通过SiO2溶胶浸渍和热处理,在炭纤维表面制备SiO2涂层。采用扫描电镜、X射线衍射仪观察和分析SiO2改性炭纤维的表面形貌及涂层成分,通过热重分析研究纤维样品的氧化行为,用数字电桥测试样品的电阻并计算电阻率,用微波矢量网络分析仪测试纤维的电磁参数并计算微波反射系数。结果表明：表面涂覆SiO2使炭纤维起始氧化温度提高近200℃,改性炭纤维的复合电阻率为纯炭纤维电阻率的2.6倍。SiO2涂层厚度为3 mm的炭纤维环形试样在7~15 GHz频率范围内的反射系数低于5 dB,反射系数小于10 dB的吸收带宽为5 GHz,在8.7 GHz频率位置具有最大吸收峰,反射率为26.2 dB。表面涂层SiO2有利于增强炭纤维的微波吸收性能。The carbon fiber was coated with SiO2 by the sol-dipping method and heat treatment.The morphology,coating composition,oxidation mass loss behavior and electric property of SiO2 modified carbon fibers were characterized by SEM,XRD,thermogravimetric analyzer,and digital electric bridge.The vector network analyzer was employed to the measurement of the electromagnetic parameters of SiO2 modified carbon fibers,on which the calculation of the microwave reflectivity was conducted.The results indicate that SiO2 modified carbon fibers exhibit better oxidation resistance performance by increasing the initial oxidation temperature from 450 ℃ to 650 ℃.In addition,the compound resistivity of SiO2 modified carbon fiber is 2.6 times as that of pure carbon fiber.The reflectivity factor of a thickness of 3 mm absorber containing SiO2 modified carbon fibers is less than 5 dB at the frequency range of 7~15 GHz,which includes a approximately 5 GHz frequency band below 10 dB with the lowest reflectivity of 26.2 dB at the frequency of 8.7 GHz.It is concluded that SiO2 coating can enhance the microwave absorbing property of carbon fiber.

关 键 词：炭纤维 SiO2涂层 微波吸收 抗氧化 

分 类 号：TM25[一般工业技术—材料科学与工程]