Hardening behavior of Al-0.25Sc and Al-0.25Sc-0.12Zr alloys during isothermal annealing

The hardening behavior of Al-0.25Sc and Al-0.25-0.12 (wt.%) alloys during isothermal annealing were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), optical microscopy (OM), and hardness measurements. The results show that Sc-containing aluminum alloy contained fine dispersion of spherical secondary Al3Sc particles, which developed during the annealing process. Al-3(Sc, Zr) precipitates in the Al-0.25Sc-0.12Zr alloys are core-shell structure. Different isothermal annealing temperatures can lead to different strengthening effects on the alloys. Al-0.25Sc and Al-0.25Sc-0.12Zr alloys both exhibit obvious annealing hardening behavior, and the ternary Al-0.25Sc-0.12Zr alloy shows better thermal stability than Al-0.25Sc alloy. (C) 2019 Elsevier B.V. All rights reserved.