Electric properties of monophase polycrystalline sinters SiC, B_4C, TiC and their composites as non-inductive volume resistors

摘要

Monophase polycrystalline SiC, B_4C, TiC and their SiC-TiC, SiC-B_4C composite sinters with a theoretical density of 97% are characterized by good mechanical and thermal durability as well as a wide range of electrical conductivity values. SiC, which has semiconductor conductivity and negative TCR, was combined with TiC, which has metallic conductivity and positive TCR. Produced in this way resistive elements, within a temperature range from 293 K to 348 K, exhibit a TCR close to zero, and an impedance independent of frequency within a range from 100 Hz to 1 MHz. The combination SiC with 40 wt% of B_4C has been produced resistive elements, which are resistive to oxidation. This combination has also completly resistive character, within a range of 100 Hz to 1 MHz. Most of the investigated materials are suitable for high temperature, noninductive volume resistors.