SiC particle reinforced A356 aluminum matrix composites with 15% in mass fraction was prepared by stirring casting

and prepared composites were deformed by hot extrusion process.Microstructure and mechanical properties of the prepared composites were investigated by OM（optical microscope）

SEM（scanning electron microscope）and tensile testing.The results show that

SiC particles are distributed uniformly in the alloy matrix

and there exists the enrichment of Si atoms in the interface of SiC/Al.After hot extrusion deformation

casting defects such as porosity are distinctly decreased

resulting in the great improvement of the composites density

meanwhile

directional distribution of SiC particles along the direction of the metal plastic flowing can be observed with the increase of uniformly dispersed SiC particle.After 535℃/5 h solid solution +180℃ /5 h aging treatment

the mechanical properties of hot extruded composites in which approximately 200 nm precipitates with dispersed distribution are observed can reach 370MPa in tensile strength

225MPa in yield strength and 5.3% in elongation.Fracture mechanism of SiCp/A356 aluminum matrix composites is characterized by plastic fracture of matrix alloy and SiC particle fracture.