Fuel ignitor comprising a novel silicon carbide composition

Claim 1

An electrical fuel igniter comprising an elongated body having a composition comprising particulate silicon carbide having an average particle size of less than about twenty microns pressed at a temperature of from about 1800° to about 2400° C. at a pressure of from about 70 to about 750 kilograms per square centimeter for a sufficient time to obtain a density above about 2.5 grams per cubic centimeter, said composition further comprising at least 95.0 weight percent silicon carbide containing from about 0.005 to about 0.05 moles per 100 grams of composition of at least one dissolved negative doping element, said at least one negative doping element being in sufficient mole excess of the total moles of all positive doping elements present in said composition to provide sufficient negative doping to said composition to reduce the cold volume resistivity to less than about 1.25 ohm cms and to reduce the ratio of cold volume resistivity at 20° C. to hot volume resistivity at 1200° C. of less than about 12 to 1, wherein the ignitor is a bar having a length of from about 0.1 to about 5 centimeters and a cross sectional area of from about 0.0002 to about 0.004 square centimeters.