Silicon carbide particle reinforced aluminum composite SiCP / Al was fabricated by pressureless infil
tration technology. The effects of alloying elements on infiltration process were studied. The influence of SiC volume
fraction on thermo physical properties of composite was investigated as well. It was found that magnesium improved in
terface wettability and silicon depressed the harmful interface reaction. With the increasing of SiC volume fraction, the
values of thermal conductivity and linear expansion coefficient of the composite decreased. When the SiC volume frac tion approached 65 percent, the decrease of thermal conductivity slowed down. When the SiC volume fraction approached 68 percent, linear expansion coefficient rapidly decreased.