Electrical resistivity measurement of carbon-fiber-reinforced ceramic matrix composite under thermo-mechanical load

The paper presents the measurement strategy and results of electrical resistivity of carbon-fiber reinforced hybrid carbon and SiC matrix composite commonly used for high heat load applications. Electrical resistance is measured for varying tensile stress up to 120 MPa and temperature in a range from room temperature to 1970 K. At room temperature, the resistivity is 37.4 ± 0.4 μΩ m and increases with tensile load. With each 10 MPa load step, resistivity increases by up to 0.7 μΩ m with residual resistivity increase of up to 0.4 μΩ m. For the elastic regime, the gauge factor is determined to 6.41. Dependence of temperature is even stronger with linear trend. It has negative trend until 1700 K with a resistivity decrease with eα/T with coefficient α = 207 K. An empirical formulation is given to relate resistivity to stress and temperature.