Uncovering the role of nanoscale Si particles on  the thermal stability of  a lamellar-nanostructured Al–1%Si alloy

This study investigates particle governed thermal stability in lamellar-nanostructured Al–1.0%Si using in-situ transmission electron microscopy and post-mortem observations. Microstructural coarsening, dominated by Y-junction motion, is correlated with dispersed Si nanoparticles. Si particles within lamellae efficiently hinder dislocation movement during deformation, fostering a configuration with Si particles along incidental dislocation boundaries (IDBs). This particle–IDB configuration significantly impedes Y-junction motion, retarding lamellar coarsening. The enhanced pinning force from particle–IDB synergy, combined with direct pinning by Si particles, contributes to improved thermal stability in lamellar-nanostructured Al–1.0%Si.