Catalytic graphitization of carbon/carbon composites by lanthanum oxide

Abstract

Graphitized carbon/carbon composites were prepared by the process of catalytic graphitization with the rare-earth catalyst, lanthanum oxide (La2O3), in order to increase the degree of graphitization and reduce the electrical resistivity. The modified coal tar pitch and coal-based needle coke were used as carbon source, and a small amount of La2O3 was added to catalyze the graphitization of the disordered carbon materials. The effects of La2O3 catalyst on the graphitization degree and microstructure of the carbon/carbon composites were investigated by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The results showed that La2O3 promoted the formation of more perfect and larger crystallites, and improved the electrical/mechanical properties of carbon/carbon composites. Carbon/carbon composites with a lower electrical resistivity (7.0 μΩ·m) could be prepared when adding 5 wt.% La2O3 powder with heating treatment at 2800 °C. The catalytic effect of La2O3 for the graphitization of carbon/carbon composites was analyzed.