Microstructure and properties of carbon-ceramic composite prepared by hot-pressing sintering

The recrystallized carbon-ceramic composites were prepared from calcined coke, coal-tar pitch and Cr by hot-press to investigate the effects of Cr on the physical properties, mechanical properties and microstructure of recrystallized graphite. Experimental results showed that Cr doped recrystallized graphites exhibited higher bending strength and compressive strength and lower electrical resistivity when the Cr content is10wt% compared with pure graphite. Microstructural analyses revealed that the degree of graphitization of recrystallized graphite increased and the layers spacing of microcrystalline decreased with increasing the Cr concentration. XRD analysis indicated that Cr added to the carbon substrate was in the form of C, Cr₂C₃ and Cr₂O₃. The catalytic mechanism of Cr dopant to accelerate the graphitization of carbon substrates can be explained by the mechanism of decomposition of the carbide.