Three-dimensional LEAP tomographic reconstructions of Al–0.06 Sc–0.02 Tb and Al–0.06 Sc–0.02 Tm (at.%) aged for: (a) 10 minutes, and (b) 24 hours at 300 °C. Each reconstruction is divided into three sections, with Sc atoms only displayed in the leftmost section, rare earth (RE) atoms only displayed in the center section, and both Sc and RE atoms displayed in the rightmost section. After 10 minutes aging time, nanometer-sized RE-rich Al3(RE1-xScx) precipitates have formed. With continued aging to 24 hours, a core-shell structure is evident in the precipitates, with a RE-rich core surrounded by a Sc-rich shell.
(Courtesy: Matt Krug)