Effect of Dispersion of ZrB2 on Resistivity of SiC-ZrB2 Electroconductive Ceramic Composites

Relationships between the resistivity and the dispersion state of ZrB2, particles and aggregates, in SiC-ZrB2 electroconductive ceramic composites were investigated by means of image analysis and other measurements. The resistivity decreases with increasing number of longer ZrB2 which has larger aspect ratio, length/average width. The aspect ratio of ZrB2 increases as the length and the content of ZrB2 increase, except for large ZrB2 aggregates which are formed due to insufficient mixing of SiC and ZrB2 powders.