50%SiCp/Al composites were prepared by powder thixoforming method

and effects of different SiC particle size combinations on microstructure and properties of the composites prepared were expounded.The results show that the SiC particles with different particle size combinations in the composites are distributed uniformly with absence of obvious conglomeration

and the density reaches more than95% with compact structure.The density and bending strength can be improved obviously by the proportioning of different particle sizes

and the main fracture mode is characterized by the brittle fracture.Bending strength of the SiCp/Al composites is in range of 270

3

82 MPa with the thermal conductivity at 111

1

46W·m-1·℃-1.Meanwhile

the mean linear coefficient of thermal expansion of composites from room temperature to 200℃is less than 6×10-6℃-1

meeting the requirement of electronic packaging.