Fig. 5: In-situ observation of aluminum grain growth during isothermal annealing using single-frame projection imaging.

Time evolution of a single grain at t, t + 100 s, t + 300 s, and t + 500 s. The false-color map represents diffracted intensity, where brighter regions correspond to higher intensity. The pink dashed line marks the grain boundary at each time step, providing a reference for changes in grain shape and size. The outer boundary at t is overlaid on all subsequent time steps to highlight grain evolution relative to its initial state. Arrows indicate significant grain boundary motion: pink for growth and light pink for shrinkage. These images are single DFXM projections, acquired at fixed ϕ and χ using a pink beam, with 400 ms exposure at 450 ^∘C. No angular scans were performed; the intensity reflects the integrated diffraction signal from the illuminated volume at the given orientation. The initial time step (t) corresponds to more than 1000 s of annealing, as detailed in the SI. A movie showing the full grain boundary evolution is provided in the Supplementary Video 1. Further details on the annealing history and measurement conditions are given in Supplementary Fig. 7.