Microstructure and properties of Sip/4032Al composite

The environmental-friendly Sip/4032Al composite with high content of silicon particles (65%, mass fraction) was fabricated by squeeze-casting method. The results show that the composite is dense and silicon particles are distributed uniformly. Transmission electron microscope observations show that a high density of stacking faults, twins and dislocations are found in silicon particles. The Si-Al interfaces are well-bonded and no interface reactants are found. The dislocations and eutectic silicon precipitates are observed in 4032A1 matrix. The Sip/4032Al composite has low density (2.4 g/cm3), low coefficient of thermal expansion (8.1 X 10(-6)/ deg C), high thermal conductivity (161.3 W/(m * )), and the annealing treatment can reduce the coefficient of thermal expansion and improve the thermal conductivity. Moreover, the composite has excellent special strength (131.8 MPa * cm3 /g) and special modulus (49.7 GPa * cm3/g).