Microstructure and thermo-mechanical properties of pressureless infiltrated SiCp/Cu composites

The microstructure, infiltration mechanism and thermo-mechanical properties of high volume fraction (61%) SiCp/Cu composites produced by pressureless infiltration were investigated. It is found that intensive chemical reaction occurred at the interface between metal and SiC preform. Alloying elements accelerated the dissolution of SiC particles. It is the dissolution of Si that facilitates the wetting and infiltration of copper alloy into porous SiC preform. High infiltration temperature and long exposure time enhanced the degree of interfacial reaction. Thermal conductivity of SiCp/Cu composites was relatively low, mainly due to the intrinsically low thermal conductivity of the matrix. Elastic modulus is insensitive to alloying elements, while bending strength depends strongly on microstructural characteristics and matrix alloying. SiCp/Cu composites exhibit brittle failure mode. Severe interfacial reaction impaired the mechanical properties.