中文摘要：

对炭黑-碳纤维硅橡胶导电复合材料的伏-安特性进行了DC/AC测试.测试结果表明：该种导电复合材料具有非欧姆特性,电压与电流之间具有非线性关系.交流测试情况下,当交流电激励频率变化较小时,输出电流基本不受影响;而当频率变化较大时,输出电流发生了较明显变化,电流随着频率的增大逐渐增大.由此可知试样的电阻抗随着交流频率的增大而不断减小.在炭黑-碳纤维硅橡胶导电复合材料的导电体系中,隧道导电（电容阻抗）与搭接/接触导电（电阻阻抗）同时存在,隧道电流是非欧姆特性及频率增大时阻抗减小的主要原因.结果分析表明：对该类导电复合材料进行电阻（抗）测试时,需了解所使用测试仪器的激励电源模式.

英文摘要：

The voltage-current characteristics of carbon and carbon fiber reinforced silicone rubbermatrix conductive composites were tested under DC or AC voltage.The result shows that the conductive compo-sites have non-ohmic behavior with nonlinear relationship of voltage and current.The current output is not affected for small change of AC excitation frequency,but decreases significantly with the frequency increase for large change.The sample impedance decreases with the increase of frequency in different AC frequency test.Tunnel conductivity（capacitance impedance） exists simultaneously with lap joint/contacts conductivity（resistance impedance） in the conductive composites,and the tunnel current is main factor for above phenomenon.The results show that it is important to know the excitation power model during electric property test of conductive composites.