The effects of the amount of Si added to Al-8Mg alloy on the microstructure and thermal conductivity of pressureless infiltrated SiCp/Al composites were investigated.The results show that Si addition to matrix can reduce the porosity of the infiltrated composites by the improvement of SiC/Al wettability,suppress the SiC/Al interfacial reaction and increase the relative density of the infiltrated composites.Without Si addition to Al-8Mg alloy,the composites exhibited a lower thermal conductivity and relative...