In order to accurately predict the variation rule of the effective permittivity and component content of silicon carbide (SiC) composites, the dielectric constants of SiC nano-particulate and its composites have been investigated by experiments and theoretical calculation. Based on the measured relative effective permittivity of samples with different SiC concentration, a calculation method for effective permittivity was established by modifying effective medium formula and Debye model. By the proposed formulas, the intrinsic permittivity of SiC versus frequency was revealed. The effective permittivity of SiC composites as a function of filling content and frequency was also explored. The relative deviation between the theoretical values and the experimental data was less than 5%. The frequency dispersion characteristic of the dielectric parameters of the component as well as the effect of the fillers on the depolarization field of the composite system was fully taken into consideration during the effective permittivity model establishing. Therefore the proposed effective permittivity model should be suitable for both low-filling and high-filling concentration systems.

为了准确预测碳化硅（SiC）复合材料的有效介电常数和组分含量的变化规律，通过实验和理论计算研究了SiC纳米颗粒及其复合材料的介电常数。根据实测不同SiC含量样品的相对有效介电常数，通过修改有效介质公式和Debye模型，建立了有效介电常数的计算方法。通过提出的公式，揭示了SiC的固有介电常数与频率的关系。还研究了SiC复合材料的有效介电常数与填充含量和频率的关系。理论值与实验数据之间的相对偏差小于5％。建立有效介电常数模型时，应充分考虑组分介电参数的频散特性以及填料对复合体系去极化场的影响。因此，建议的有效介电常数模型应适用于低填充和高填充浓度系统。