Effect of silicon particles on the rapidly resolidified layer of Al-Si alloys in the electro discharge machining process

Abstract

The rapidly resolidified layer is formed by the re-solidification of residual molten materials on the machined surface during the electric discharge machining (EDM) process. This study adopts a range of 4–29 wt% to change the silicon content in Al-Si alloy specimens to clarify the effect of silicon particles including the content, area fraction and intercept length of primary silicon particles on the performance of the rapidly resolidified layer during the EDM process. The layer thickness, surface roughness and ridge density on the rapidly resolidified layer are considered in the performance evaluation and explored by experiment. Experimental results indicate that the EDMed surface has a continuous ridge appearance and the effect of silicon particles including the content, area fraction and intercept length of primary silicon particles has the advantage of more ridge density. The rapidly resolidified layer thickness and surface roughness on the EDMed surface tend to increase with increasing the content and area fraction of the silicon particles.