Recrystallization performance of AA7050 varied with Sc and Zr

The elements Sc and Zr are known to impart increased recrysrallization resistance in aluminum alloys by employing Al3Sc and Al3Zr dispersoids, respectively. Developing elevated recrysrallization temperatures in wrought aluminum alloys is important for the retention of mechanical properties developed during thermo-mechanical processing. The interactions of Sc and Zr additions in precipitation hardenable 7xxx alloys are studied in this work. Of the two dispersoids mentioned, only Al3Zr is used in some 7xxx alloys. We show that the use of both Sc and Zr in 7050 is more effective than Zr acting alone. Emphasis is given to the evolution of microstructure as affected by Sc content, Zr content, homogenization, hoc rolling, and annealing, The results of optical microscopy, TEM, and EDS are included in this work.