DC conductivity of silicon nitride based carbon-ceramic composites

Abstract

The silicon nitride ceramics are usually known as strongly refractory and enduring materials and have typical electrically insulating properties. If the reinforcing phase of ceramic composite (that is mainly put in the material to improve mechanical properties) is a good electrical conductor, it is worth to investigate the composite in electrical aspect. In this work carbon nanotubes, black-carbon and graphite were added to the basic silicon nitride ceramic and the electrical conductivity of the prepared carbon-ceramic composites was determined. The conductivity of the ceramic composites with different type and concentration of the carbon additives was observed by applying four point DC resistance measurements. Insulator and conductor composites in a wide conductivity range can be produced depending on the type and quantity of the additives. The additive types as well as the sintering parameters have influence on the basic electrical properties of the conductor composites.nema