Resistance material based on silicon carbide

Silicon carbide is used for high-temperature electric heating elements [I]. However, high-density sintered SiC has a relatively low electrical resistivity, on the order of 10 -I ~-cm, and a high negative temperature coefficient of resistivity (TCR) in the temperature range from room to 800-900~ [i], and this makes it unsuitable for the manufacture of fixed network voltage heating elements of small linear dimensions which could replace the shortlived spirals. In this connection, there is interest in possible ways of producing silicon carbide materials of higher resistivity and lower TCR. In the present work the electrical resistivity of silicon carbide was increased by decreasing its density. At the same time, to increase its mechanical strength, decrease its negative TCR, and lower its sintering temperature, silicides of the transition metals Ni, Co, Fe, V, Mn, and Cr were added to it.