The Effects of Electric Pulse Modification on Eutectic Al-12.6%Si alloy

Abstract

Al-Si alloy at eutectic region as the research object, Electric pulse modification (EPM) were used to achieve simultaneous refinement and modification of eutectic silicon phase, in order to analyze the mechanism of electrical pulse modification to the alloy and analyzed how the EPM affects the solidification structure and the corresponding properties. We get the conclusion by observing the microstructure of the sample, measuring the hardness, calculating the volume fraction and the average size of primary silicon at different pulse frequency and voltage. By using this process the particle size of primary silicon was reduced from 50 µm to a range of 5-20µm and the shape changes from acicular to fine fiber when compared with the conventional casting process. Also, the result of mechanical test showed that the hardness increase from 105HV-156HV with the change in pulse voltage at 700V peak value it therefore increased with 49% and at 1000V decline to 144HV with increased by 37% with homogeneous distribution of eutectic silicon.