Fabrication of electrically conductive Si3N4 ceramics by dispersion of carbon nanotubes

Electrically conductive Si(3)N(4) ceramics were fabricated by dispersion of different characteristics of carbon nanotubes (CNTs). When the sintering aid of Y(2)O(3)-Al(2)O(3)-TiO(2)-AlN was used for lower temperature densification, it was confirmed that CNTs existed in Si(3)N(4) ceramics from SEM observation and SiC was not identified in XRD analysis, which means that CNTs did not react with Si(3)N(4). Relative density and electrical conductivity of the CNT dispersed Si(3)N(4) ceramics depended on the characteristics of CNTs. Aggregation of CNTs, which, is outstanding in much thinner CNTs, should limit densification of Si(3)N(4). CNTs were well-dispersed by beads milling in ethanol. As a result, beads milling process was confirmed to be effective in unraveling and dispersing CNTs. It was shown that better dispersion of CNTs with higher aspect ratio resulted in higher density and electrical conductivity.