In situ formed core–shell structured particle reinforced aluminum matrix composites

• A new metal matrix composite (MMC) has been developed.
• The developed MMC has a matrix/shell/core structure.
• The developed MMC has both high strength and plasticity.

Particulate reinforced metal matrix composites (PRMMCs) have high strength but their plasticity and toughness are usually low. Here in this paper a new PRMMC with both high strength and plasticity was successfully developed. The composite is composed of three distinct phases, including ductile matrix, ductile core phase and in situ formed hard intermetallic shell. The strength can be substantially improved by transferring the applied stress from the soft matrix to the hard shell. The propagation of the cracks in the shell during deformation can be inhibited since both tips of each crack become blunt due to the high ductility of the matrix and core phases. The designed structure provides guidance for developing new PRMMCs with high strength and plasticity.