| 摘要 |
In a spark plug (1'), a center electrode (17) is fixedly held in an axial bore (3) of an insulator (2). The center electrode (17) terminates in a free end surface (17a) of a smaller diameter. A discharge chip (12) made of a molten alloy has been joined to the free end surface (17a). The molten alloy is composed of 99 to 80 wt.% of Ir and 1 to 20 wt.% of Pt. The center electrode (17), a ground electrode (20) and a discharge chip (13), which is joined to a free end surface (20a) of the ground electrode (20) and is located opposite the discharge chip (12), can all be made of the molten alloy. <IMAGE> |
