Real-time radiographic observation of solidification behavior of AlSiCu casting alloys with the variation of iron content

Abstract

Real-time radiography using synchrotron radiation X-ray was utilized to directly observe and investigate the formation behavior of Fe bearing intermetallic phases in AlSiCu alloys. Solidification sequences of two AlSiCu alloys with different Fe content were examined in a specially designed vacuum furnace and chamber in BL20XU of SPring-8. Detailed solidification sequence and resultant phases forming reactions were confirmed by combined analyses of radiography, thermodynamic calculation and SEM-EDS. The formation behavior of primary, eutectic and peritectic α-Al 5FeSi as well as β-A l8Fe 2Si and β-Al 15(Fe,Mn) 3Si 2 were explained as a function of Fe content. The α-A l5FeSi was found to form as only small eutectic component in the low Fe containing alloy, while that was crystallized as a primary phase as well as β-Al 8Fe 2Si and β-Al 15(Fe,Mn) 3Si 2 in the high Fe containing alloy. © 2012 Japan Foundry Engineering Society.