Enhanced Strength–Ductility Synergy of AA5182/Al2O3 Aluminum Matrix Composite Produced by Friction–Stir Processing

The AA5182/Al2O3 aluminum matrix composite with enhanced synergy of strength and ductility was produced by friction–stir processing. This was achieved using a comparatively low fraction (≈1 vol. %) of nanoscale Al2O3 reinforcing particles and applying 12 consecutive passes of friction stir processing. Electron backscatter diffraction was employed for characterization of grain structure, while transmission electron microscopy was applied for examination of dislocation structure and secondary particles. The superior strength of the produced composite was due to the combined influence of the reinforcing particles and grain refinement. On the other hand, the preservation of sufficient ductility was attributed to the relatively low fraction of the reinforcing Al2O3 phase and its uniform distribution within the processed material. Thus, the fabricated composite exhibited an optimized balance of strength and ductility.