Effect of TiB2 Particles on the Thermal Deformation and Recrystallization Behaviour of Al-Cu-Mg Alloys

• • TiB2 addition at 0.1 wt% reduces grain size from 117 μm to 35 μm (70% refinement), while 1 wt% TiB2 achieves 29 μm (75% refinement), directly enhancing Hall-Petch strengthening and thermal stability for high-temperature aerospace components. • • Flow stress increases with TiB2 content due to grain boundary strengthening and Orowan looping; at 340 °C and 0.01 s−1, the 1 wt% TiB2 alloy exhibits peak stress exceeding that of the base alloy by approximately 20–30 MPa, requiring higher forming loads but enabling better shape retention during hot working. • • Dynamic recrystallization is accelerated by TiB2-induced grain refinement; at 500 °C and 0.01 s−1, the 1 wt% TiB2 alloy shows a DRX fraction of ~85% versus ~60% for the base alloy, promoting microstructural homogeneity and reducing residual stresses in forged components. • • Excess TiB2 (1 wt%) activates particle-stimulated nucleation (PSN), leading to finer recrystallized grains (average size ~10 μm after deformation at 500 °C and 0.01 s−1) and suppressing grain coarsening during post-deformation annealing, which is critical for maintaining fatigue resistance in aircraft skin materials.