Sintered ceramic heater element

Abstract

A sintered ceramic electric heater suitably applicable to a glow plug of a diesel engine has a heater element formed of an electrically conductive sintered ceramic integrally sintered with a support member made of an electrically insulating sintered ceramic material. The heater element is formed as a sintered body of a mixture of MoSi.sub.2 powder having an average diameter not greater than 2 .mu.m and 35 to 75 mol % of Si.sub.3 N.sub.4 powder. The average particle diameter of the Si.sub.3 N.sub.4 powder is at least twice as large as that of the MoSi.sub.2 powder so that electrically interconnecting MoSi.sub.2 particles surround scattered Si.sub.3 N.sub.4 particles whereby the resistance of the heater element becomes equal to that of MoSi.sub.2 and the temperature coefficient of the heater element is increased.

Dependencies are inferred from the claim text.