B4C/A356 and SiCp/A356 composites were prepared by compocasting method

and microstructure and mechanical properties of two composites prepared were investigated by SEM

OM and hardness testing

tensile testing.The results indicate that SiCp/A356 composites with uniformly distributed reinforcements SiCpcan be fabricated successfully at a lower solid fraction（about 26%）

while at a higher value（about 27%）of solid fraction

B4C/A356 composites can be prepared.Additionally

B4 C particles can react with molten Al during the preparation and lots of reaction products can be observed

however

reaction of SiCp with molten aluminum alloy is absent

and the levels of reaction products can be controlled by adding 1.2% Ti.Further more

SiCp/A356 composites have a better tensile properties due to generate a strong bonding interface.