| 摘要 |
According to the present invention, at least one of a center electrode or a ground electrode is produced by mixing a matrix metal with carbon so that the carbon content of the resultant mixture is adjusted to 80 vol.% or less; subjecting the mixture to powder compacting or sintering, to thereby form a core; placing the core in a cup formed of nickel or a metal containing nickel as a main component; and subjecting the cup to cold working. The thus-produced electrode exhibits favorable thermal conductivity and good heat dissipation, by virtue of the small difference in thermal expansion coefficient between the core and an outer shell. Therefore, a spark plug including the electrode exhibits excellent durability. |
