| 摘要 |
<p>The sintered ceramic body of this invention is a cylindrical insulator having a through hole used for spark plugs, which is characterized by comprising alumina as a main component and Sn component in an amount of 0.05 - 2 wt% as SnO and can be manufactured by a step of preparing a slurry by mixing a raw material powder comprising alumina as main component and Sn component in an amount of 0.05 - 2 wt% as SnO, water and a binder; a step of preparing a granulated powder from the slurry, a step of packing the granulated powder in a prescribed mold and pressing it to form a compact having the same shape as sintered ceramic body to be prepared and a step of sintering the compact. The spark plug of this invention is characterized by being provided with said sintered ceramic body having a through hole; a center electrode inserted in one end of said through hole; a main metal shell mounted on the outside of said one end of the sintered ceramic body, to which the center electrode is inserted; a ground electrode, which is attached to the main metal shell and has a tip closely confronting the center electrode; and a terminal which is mounted in the end of the through hole. <IMAGE></p> |
