The effect of iron and the precipitation behavior of iron during annealing of a cold deformed commercial purity aluminium alloy

Abstract

Iron is always present in any aluminium alloy and usually as an impurity element. In commercial purity alloys the concentration of iron is typically so large that iron has a strong influence on the material properties, due to its slow diffusivity and low solubility in aluminium. In the present work the effect of iron in solid solution and the precipitation behavior of iron during annealing of a colddeformed commercial purity aluminium alloy have been investigated. Iron in solution is found to have a strong retarding effect on the softening kinetics. The resulting recrystallization texture has a distinct Cube component and some weak deformation texture components. By additional cold rolling and inter-annealing, the solute content is reduced significantly by precipitation of mainly Al3Fe and some α-AlFeSi phases. Doing so speeds up the softening kinetics by a factor of ~1000 and causes a considerable strengthening of the Cube component in the recrystallized texture.