CERAMIC HEATER

摘要

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 MoSi2 powder having an average diameter not greater than 2 mu m and 35 to 75 mol % of Si3 N4 powder. The average particle diameter of the Si3 N4 powder is at least twice as large as that of the MoSi2 powder so that electrically interconnecting MoSi2 particles surround scattered Si3 N4 particles whereby the resistance of the heater element becomes equal to that of MoSi2 and the temperature coefficient of the heater element is increased.