Effect of low-level oxidation on microstructure and sample volume of 2D carbon/carbon composites

The effect of low-level oxidation,defined as a weight loss less than 6 % at 700 ℃-1 300 ℃,on microstructure and volume change of 2D carbon/carbon(C/C) composites was measured by SEM and a micrometer.Results indicated that the oxidation rate of the C/C composites was linear.Higher temperature favored for surface oxidation,which leaded to an increased burn-off but a thinner oxidized layer.Lower temperature,however,favored in-depth oxidation,which led to a decreased burn-off but a thicker oxidized layer.Separation of the carbon fibers from the substrate could be seen,The tips of the fibers were sharpened and the volume of the composites decreased.