Microstructural characterization on ZrC doped carbon/carbon composites

Zirconium carbide doped carbon/carbon (ZrC-C/C) composites were prepared by the polymer impregnation and pyrolysis process. Carbon fiber preforms were firstly immersed into zirconium acetate solution/phenolic resin impregnant, and then carbonized at 1000 °C. After four cycles of impregnation/carbonization, they were finally graphitized at 2000 °C. The phase composition of the composites was examined by X-ray diffraction. Microstructural characterization of the composites were investigated by scanning electron microscopy and transmission electron microscopy. The results indicated that ZrC particles with sub-micron size were well dispersed in carbon matrix. ZrC particles were encapsulated by highly oriented carbon, and there existed a well bonded interface between ZrC particles and highly oriented carbon. The formation mechanism of the encapsulated structure was proposed.