Microstructure and Mechanical Properties of D-SSF Processed Al-Zn-Mg Alloys with High Fe Content

Abstract:

Microstructures and mechanical properties of the D-SSF (Deformation Semisolid Forming) processed Al-Zn-Mg alloys with high Fe content up to 2 mass% were investigated. A high ductility alloy even containing 1 mass% Fe was successfully produced by applying the D-SSF process. Especially, the D-SSF processed alloy with 1 mass% Fe was superior to the conventionally processed alloy with Fe-free in the properties of the tensile strength and elongation. These results clearly indicate that the harmful influence by the addition of 1 mass% Fe is effectively modified into not harmful one by applying the D-SSF process. Furthermore, the former liquid phase regions (FLP regions) which are finally solidified during the D-SSF process are completely extinguished by the solution treatment and resultantly the mechanical properties are greatly improved. The extinction process of the FLP regions during the solution treatment was examined using an EBSD method in terms of the crystal orientations of the α-Al grains.