Abstract
The emission process of hypereutectic Al-Si alloys were investidated by using both high and low voltage spark discharges. The dependency of Si/Al intensity ratio on the primary Si particle size were studied in the samples of various Si contents and primary Si particle sizes. The emission discharge progressed from eutectic Si and progressed through the surface of primary Si particles, and reached the α-phase and the primary Si particles. In the case of high voltage spark discharge, the Si/Al intensity ratio increased exponentially with the decrease in size of Si particles. It was caused that the specific surface area of primary Si particles increased with the decrease in size of primary Si particles. In the case of low voltage spark discharge, however, changes in the primary Si particle size did not have any significant effect on the Si/Al intensity ratio.
