The Fabrication of High Silicon-Aluminum Composites and the Thermal Conductivity

Abstract

Silicon-aluminum composites with Si content of 42-70 wt. % were fabricated by an innovative method of liquid-solid separation. The microstructures and thermal conductivity analyzing and predicting by the Maxwell and Hasselman-Johnson models were executed. The results show that silicon particles in composites are near globular with dull angular and surrounded by the continuous Al matrix, and the interface among them is composed of element diffusion zone. The conductivities of four composites are beyond 120 W. m-1 .K-1 at 25°C but reduce with Si content adding. The coarse particle size is beneficial to the higher conductivity. The interface thermal resistance of composites obtained by theoretical calculation is 16.0×107 W.m-2.K-1, and using it the H-J model can be employed to predict the conductivity.