Transformation of the Metastable Al6Fe Intermetallic Phase during Homogenization of a Binary Al-Fe Alloy

Abstract

Within the scope of this research the transformation of the Al6Fe metastable phase was analyzed via Differential Scanning Calorimetry (DSC), optical and Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). A binary Al-Fe1.1 low-impurity alloy was produced with refined raw materials in a controlled environment. With a cooling rate of 35 K/s, solidification of the Al6Fe metastable phase was achieved. The samples were homogenized at 600 °C for 2–24 h. Results of a qualitative analysis of metallographic samples show that the transformation began on grain boundaries, forming an Fe-phase free region, but after 2 h began to take place within the eutectic region. The transformation is mostly complete after 12 h, but after 24 h of homogenization it is fully complete as all samples, except the 24 h homogenized one, contain both the metastable Al6Fe and the stable Al13Fe4 phase.

Size‐Dependent Corrosion of Al‐Fe Intermetallic Particles at Al‐Mg Alloy Surfaces Investigated by In‐Liquid Nanoscale Potential Measurement Technique

“…This value well corresponds to the Fe content of the most stable Al‐Fe phase, Al 3 Fe. [ 46 ] Meanwhile, the Al‐rich region showed 13 at.% Fe content ratio, which approximately corresponds to the composition of a major metastable Al‐Fe phase, Al 6 Fe. [ 46 ] Although the existence of the Al‐rich region is a clear difference between the small and large IMPs, this does not explain the difference in their corrosion behaviors.…”

“…[ 46 ] Meanwhile, the Al‐rich region showed 13 at.% Fe content ratio, which approximately corresponds to the composition of a major metastable Al‐Fe phase, Al 6 Fe. [ 46 ] Although the existence of the Al‐rich region is a clear difference between the small and large IMPs, this does not explain the difference in their corrosion behaviors. Thus, the compositional difference is unlikely to induce the different corrosion behaviors.…”