Abstract
The electrode shape of the spark plug affects its breakdown voltage, ignitability and spark erosion. A thin electrode (dia = 0.5 mm)improves these characteristics except for spark erosion. This paperpresents a spark erosion mechanism under glow discharge for developing material suitable for the thin electrode. The results suggest that the spark erosion mechanism is related to sputtering under glow discharge and that the spark erosion volume is decreased by dispersing a rare earth metal oxide into iridium (Ir). (A)