Characterization of oxidation behavior of 3D needled C/C composite by Synchrotron radiation X-ray micro-computed tomography

Abstract

C/C composite has been considering to be used as structural components in the field of nuclear energy. However, the material will be subjected to rapid oxidation in the air. This paper presents the microstructure evolutions of a type of high density C/C composites at 550 °C in the air. Synchrotron radiation X-ray micro-computed tomography (SR-µCT, resolution: 0.65 µm) was used to characterize the microstructure in different oxidation stages. The results showed that the material was oxidized nearly homogeneous. The large pores played great rule in the oxidation behavior. The pores in the material started to extend quickly in initial stage and the number of pores and porosity were rapidly increased. Then the oxidation rate decreased as defective graphite in the composition exhausted. In addition, it also can be seen that SR-µCT is a perspective tool for microstructural characterization, especially structure evolution in 3D in the materials.