竹炭/SiC复合材料结构及其吸波性能  

Structure and Microwave Absorption Properties of Bamboo Charcoal/SiC Composites

作　　者：武志红[1] 李妤婕 张聪[1] 尚楷 丁冬海[1,2] 薛群虎 

机构地区：[1]西安建筑科技大学材料与矿资学院,西安710055 [2]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

出　　处：《硅酸盐学报》2018年第1期150-155,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金青年基金(51502236);国家自然科学基金(51372193);高温性能陶瓷与超微结构国家重点实验室开放课题资助(KL201403SIC);陕西省教育厅专项科研项目(14JK1393);西安建筑科技大学基础研究基金(JC1496)

摘　　要：以Si粉、竹炭为原料,采用包埋法制备具有类蜂窝结构的竹炭（bamboo carbon,BC）/SiC复合材料。结果表明：BC/SiC复合材料主要由β-SiC相、少量α-SiC相和非晶碳组成。BC/SiC复合材料呈蜂巢状多孔结构,孔内壁分布着直径不同、相互熔结连接的SiC三维聚集体结构层,其断裂韧性为18.8 MPa·m^1/2,弯曲强度为34.5 MPa。BC/SiC复合材料形成的两相界面,提高了BC/SiC复合材料的吸波性能：介电常数实部最大值为9.14,虚部最大值为2.06;样品厚度为2.5 mm时,在10.7 GHz处,最低反射系数为–10.16 dB;反射系数〈–8 dB的有效吸收带宽达2.1 GHz。The bamboo charcoal（BC）/SiC composite with a special honeycomb-like structure was prepared by an embedded sintering method with silicon powder and bamboo charcoal as raw materials.The morphology and phase composition of BC/SiC composite were investigated by scanning electron microscopy and X-ray diffraction.The dielectric properties of BC/SiC composite materials were investigated by a rectangular waveguide method.The results indicate that the main phases of BC/SiC composite material are β-SiC and amorphous carbon,and there is a small amount of α-SiC phase.The BC/SiC composite material has a honeycomb-like porous structure with three-dimensional aggregation structure layers,which have different diameter sizes and consist of interconnected SiC.The fracture toughness and bending strength of BC/SiC composite are 18.8 MPa·m^1/2 and 34.5 MPa,respectively.The interface between the crystal structures of SiC/BC composite material improves the microwave absorbing absorption properties of SiC/BC composite.The maximum real part of dielectric constant of BC/SiC composite is 9.14,and the maximum imaginary part is 2.06.The lowest reflection coefficient is –10.16 dB at 10.7 GHz,and the effective absorption bandwidth is 2.1 GHz with the reflection coefficient of lower than –8 dB when the sample thickness is 2.5 mm,showing the good absorbing absorpation performance of BC/SiC composites.

关 键 词：竹炭 碳化硅 复合材料 包埋烧结 吸波性能 

分 类 号：TB332[一般工业技术—材料科学与工程]