Abstract: The characteristics of oil absorption and desorption on carbon-carbon composites is researched using hydraulic fluid (type YH-10).The mechanism of oil absorption is put forward. The relationships between oil amount in the specimens and time are established. The test results show that the oil absorption rate in carbon-carbon composites is rapidly increased in the beginning term of the immersion process and slowed-up subsequently, and ultimately reaches saturation value of about 4%. In the process of desorption, the residual oil amount in carbon-carbon composites is dominated by the temperature, time and heating method. But the temperature is the dominant factor. Higher the temperature is, the better the clearing effect is. The residual oil amount in carbon-carbon composites is much smaller at 200℃ than that at 100℃. However, the residual oil amount in them has little change when the temperature is raised from 100℃ to 150℃, which suggests that there is a limitation temperature to remove the residual oil from the interior of carbon-carbon composites. Over 200℃ is suitable to the oil desorption in the interior of the composites. The effect of removing oil is better using microwave heating than using the oven heating. The microstructures of specimens are analyzed by the polarization microscope and scanning electron microscope.

Key words: absorption oil, desorption oil, carbon-carbon composites, microwave heating