SiC_p/2024 and SiC_p/6061 composites were prepared by pressure infiltration method with volume fraction of SiC of 25%,30%,35%,40%,45%and 50%,respectively.The effects of the volume fraction of SiC particles on the microstructure and properties of the composites prepared were investigated by SEM,OM,EDS and tensile testing,and the effects of heat treatment on the mechanical properties of the composites were analyzed.The experimental results show that the hardness,tensile strength and compressive strength of SiC_p/2024 and SiC_p/6061 composites are increased obviously with the increase of SiC volume fraction,while the elongation is obviously declined.The fracture mode of the composites is characterized by brittle fracture.With the volume fraction of SiC of 50%,the hardness,compressive strengths and tensile strengths of SiC_p/2024 and SiC_p/6061 composites reach up to HB243.34 and HB154.97,840.63 MPa and 519.83 MPa,340.2 MPa and 300.5 MPa,respectively.After solid solution and aging treatment,the strength and hardness of the two kinds of composite are increased,while the elongation is decreased.The properties of the composites with higher volume fraction of SiC are improved greatly after heat treatment,and the improvement of properties of SiC_p/6061 composites is more obvious than that of SiC_p/2024 composites.