Improving the mechanical strength of carbon–carbon composites by oxidative stabilization

Carbon/carbon composite has superior properties, so it has been expected to use various industrial fields. However, low mechanical strength (than conventional structural materials) works as a hurdle, so the use of oxidative stabilization to improve the mechanical strength of carbon/carbon composites was studied. The oxidation process was performed at 220–350 °C based on thermogravimetric analysis (TGA). The compressive strength of the oxidized sample at 290 °C was 212 MPa, which is 2.5 times greater than that of the non-oxidized sample (84 MPa). However, the oxidation temperature of more than 290 °C decreased the compressive strength (199 MPa at 350 °C). This tendency was in accordance with the TGA and X-ray photoelectron spectroscopy (XPS) results. The effect of oxidative stabilization can be explained by two factors: the polymerization of the used binder pitch by the crosslinking effect by induced oxygen and improvement of the affinity between the coke and binder pitch.