Carbon nanotube buckypaper-reinforced SiCN ceramic matrix composites of superior electrical conductivity

SiCN ceramic matrix composites impregnated with multi-walled carbon nanotubes buckpapers (BP) were prepared by precursor infiltration and pyrolysis (PIP). Microstructure, pore size distribution, density, phase composition and electrical conductivity of buckypaper/SiCN composites were analyzed by means of electron microscopy, mercury intrusion, Archimedes method, X-ray diffraction and four-probe electrical measurements, respectively. Composite density was found to increase with increasing number of PIP cycles and the final value of 2.15 g/cm³ realized, indicated complete and successful impregnation and pyrolysis of the ceramic precursor solution in the nanotube network of the BPs. An impressive increase by 200%, of the electrical conductivity of buckypaper/SiCN composites compared to pristine BPs, from 61.5 S/cm to 185 S/cm, is reported and attributed to the conductivity of the crystal phases comprising the matrix.