Development of Conductive Ceramic Composites by Preceramic Polymer

摘要

The formation, microstructure and electrical property of conductive ceramic composites derived from polymer pyrolysis were investigated. Methylpolysiloxane was mixed with TiH_2 as a filler and pyrolyzed in nitrogen, argon and vacuum atmosphere at a temperature of 1600°C for 1 hour after the preheat treatment at 850°C in N_2 atmosphere. Depending on the atmosphere conditions, TiN and Ti_5Si_3 phases were formed by reaction of TiH_2 as reactive filler and atmospheric gas orpyrolytic product such as SiO_2. Consequently, the microstructures of the ceramic composites with 70 vol.%TiH_2 pyrolyzed at 1600°C for 1 hour in vacuum were composed of TiN and Ti_5Si_3 particles. The density and electrical conductivity of the ceramic composites were 97.3 TD% and 6200 ohm~(-1) cm~(-1) , respectively. These composites pyrolyzed by polymer were considered as superior conductive material with a value of 10~3 ～ 10~4 in log scale at room temperature.