The SiCp/6061 aluminum matrix composites with SiC particles in range of 20 to 50μm were prepared by semi-solid stirring casting.Effects of SiC particle size on the microstructure and properties of SiCp/6061 aluminum matrix composites were investigated.The results indicate that the dispersion uniformity of SiC particles in aluminum matrix composite is improved with increasing in SiC particle size

however

the tensile properties and elongation are decreased.Fracture mechanism of the composites is characterized by co-action of interfacial de-bonding and particle cracking.The particle crack plays a dominant role in crack mechanism with SiC particle size increase.With the increase of SiC particle size

wear resistance of SiCp/6061 aluminum matrix composites is increased.The friction and wear mechanism can be described by adhesive wear and abrasive particles wear

and the abrasive wear will play the dominant role with increasing in SiC particle size.