Grain refinement in extruded A6063 Al alloy using additively manufactured billets

In this study, we developed a new process for grain refinement in the A6063 aluminum alloy using extrusion with aluminum billets fabricated by additive manufacturing. The resultant extruded profile exhibited fine grains with an average diameter of 3 μm and displayed a fibrous structure elongated in the extrusion direction. The internal microstructure exhibited the typical texture of a plate-shaped extruded profile, characterized by < 001 > + β-fiber{110} < 112 > . The results obtained using this method were superior to those obtained using the conventional approach, in which cast billets were used for A6063 extruded profiles. Specifically, the tensile strength and elongation values improved by 10% and 40%, respectively. Additionally, we detected the development of a yield point (which is generally not observed in aluminum alloys). This outcome confirmed that uniform fine grains were successfully obtained using this process. In addition, this method facilitated the production of extruded profiles, with complex cross-sectional shapes and fine grains, in an alloy with a low transition-metal concentration, such as the A6063 alloy (whose manufacturing has hitherto remained challenging).