Preparation and anisotropic thermophysical properties of SiC honeycomb/Al-Mg-Si composite via spontaneous infiltration

Abstract The SiC honeycomb/Al-Mg-Si composite with interpenetrated microstructure was prepared by spontaneous infiltration of Al-8wt%Mg-7wt%Si alloy into directional porous SiC honeycomb served as reinforcement. The microstructure and anisotropic thermophysical properties of this composite were also examined. The results showed that the initial microstructure of the SiC honeycomb can be retained and the as-prepared SiC honeycomb/Al-Mg-Si composite exhibited significantly anisotropic characteristics. Meanwhile, the alloying treatment on the Al matrix can avoid the generation of Al 4 C 3 and promote the wettability between Al and SiC. Particularly, the directional porous SiC honeycomb with such a low ceramic content (19 vol.%) made it possible for the composite to have a higher thermal conductivity (138.3 W/(m∙K)) in the axial direction and a lower coefficient of thermal expansion (11.40 × 10 −6 /K) in the radial direction. The influences of the SiC honeycomb reinforcement on the anisotropic thermophysical properties were also studied by the theoretical models in comparing with the experimental results.