A nanostructural design to produce high ductility of high volume fraction SiCp/Al composites with enhanced strength

• Nanostructured matrix in high volume fraction of SiCp/Al composites was achieved.
• Nanostructured matrix was achieved by adding nucleating elements Sc and Zr.
• The formation mechanism of nanostructured matrix was preliminarily indicated.
• The nanostructured composites showed an improvement of 300% in maximum strain.

High ductility and increased strength of SiCp/Al composites are highly desirable for their applications in complicated components. However, high ductility and high strength are mutually exclusive in high volume fraction SiCp/Al composites. Here, we report a novel nanostructuring strategy that achieves SiCp/Al–Sc–Zr composites with superior maximum tensile strain and enhanced tensile strength. The new strategy is based on combination of grain refinement down to ultra-fine scale with nanometric particles inside the grain through adding distinctive elements (Sc, Zr) and refining nucleation centers to nanoscale under the action of high volume fraction reinforcement during the fabrication process. The nanostructured SiCp/Al–Sc–Zr composites had an increase of ∼300% in maximum tensile strain and a 21% increase in tensile strength. This thought provides a new sight into enhancement of both strength and ductility of particle reinforcement metal matrix composites.