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

摘要

High ductility and increased strength of SiC_p/Al composites are highly desirable for their applications in complicated components. However, high ductility and high strength are mutually exclusive in high volume fraction SiC_p/Al composites. Here, we report a novel nanostructuring strategy that achieves SiC_p/ 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 nanostruc-tured SiC_p/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.