Investigation of a solid-state transformation of dispersed intermetallic particles in aluminium alloy from an Al6(Fe,Mn) phase to an α-Al(Fe,NIn)Si phase

Homogenisation of direct-chill (DC)-cast aluminium alloy for beverage-can applications results in a partial phase transformation of coarse eutectic intermetallic particles, in which a tetragonal Al-6(Fe,Mn) phase changes to a cubic alpha-AI(Fe,Mn)Si phase. We have used an array of techniques to increase physical understanding of the transformation. Elemental maps, acquired using EFTEM, were used to analyse diffusion of elements involved in the transformation. A FEGSEM was also used to investigate the three-dimensional morphology of deep-etched specimens, whilst convergent-beam electron diffraction was used to study crystallographic orientations of eutectoid aluminium.