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The formation of Fe-rich intermetallics in gravity die cast and squeeze cast Al-5.0 wt-% Cu-0.5 wt-% Fe alloys with different Mn contents was investigated. In gravity die cast alloys, the predominant Fe-rich intermetallics are AlmFe and β-Fe with lower Mn contents, but α-Fe and Al6(FeMn) are predominant when the amount of Mn increases. A lower amount of added Mn is required in the squeeze cast alloys because the applied pressure is favourable for the formation of Chinese script Fe-rich intermetallics and for preventing precipitation of the needle-like intermetallics. The formation temperature increases for α-Fe and AlmFe but decreases for β-Fe with an increase in the applied pressure. [ABSTRACT FROM AUTHOR]

The iron-rich intermetallics are considered to be stable in aluminium alloys and usually hard to dissolve into the matrix during solution heat treatment (SHT). Nevertheless, solid-state transformations between Fe-rich intermetallics may happen and will play a great role in breaking-up of the large Fe-rich intermetallics particle during hot deformation process. In this study, the solid-state phase transformation of the iron-rich intermetallics from AlmFe to β-Fe (Al7Cu2Fe) has been studied using SEM, XRD and deep-etched technique in a 2xxx Al–Cu cast alloy during SHT. The mechanism of solid-state transformation for the Fe-rich intermetallics was discussed, including the solid-state reaction, nucleation and growth of iron-rich intermetallics and Al phases. [ABSTRACT FROM AUTHOR]

Cold rolling and hot rolling of solution treated Al–3·7Cu and Al–3·8Cu–1·8Mg alloys were performed to test the effect of inhomogeneous precipitation in shear bands during following aging of the material. The most effective inhomogeneous distribution of particles was observed for samples hot deformed and aged within the temperature range 473–573 K. It was noted that magnesium addition intensifies coarse shear bands development and following coarsening of particles within sheared area. [ABSTRACT FROM AUTHOR]