| 摘要 |
A fired, electrically semi-conducting ceramic body is disclosed. The body consists essentially of silicon carbide particles having a median particle size from about 3 to about 25 microns dispersed in a bonding matrix. The silicon carbode particles constitute from about 50 to about 70 percent of the body. The body has an "apparent porosity" as subsequently defined herein from 20 to 40. The production of such a body from a batch composed of silicon carbide, alumina, silica and at least one oxide, carbonate or hydroxide of calcium, magnesium, barium or strontium is also disclosed. The batch is milled and pressed into a shape, and the resulting shape is then fired in an inert gas atmosphere to a temperature from about 2300 to 2800.degree.F for a time sufficiently long to produce a semi-conductor body having the requisite apparent porosity of from 20 to 40 percent. These ceramic bodies find use in high energy igniters, suitable for use in jet engines. |
