The Effect of Iron Content on the Iron-Containing Intermetallic Phases in a Cast 6060 Aluminum Alloy

The effect of iron content, ranging from 0.1 to 0.5 wt pct, on the formation of Fe-containing intermetallic phases in a cast 6060 aluminum alloy was investigated. Various characterization techniques, including optical microscopy, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to examine the identity, morphology, and prevalence of the Fe-Al and Fe-Al-Si intermetallic phases. The predominant phase is found to be beta-Al5FeSi at lower Fe levels, but this is replaced by alpha-AlFeSi (bcc structure) with increasing Fe content. The Fe containing intermetallic phases observed are compared to those predicted using the Scheil module of THERMO-CALC software, and the similarities and discrepancies are discussed.