Fabrication and characterization of Copper/Silicon Nitride composites

Abstract

Copper/silicon nitride (Cu/Si3N4) composites are fabricated by powder technology process. Copper is used as metal matrix and very fine Si3N4 particles (less than 1 micron) as reinforcement material. The investigated powder were used to prepare homogenous (Cu/Si3N4) composite mixtures with different Si3N4 weight percentage (2, 4, 6, 8 and10). The produced mixtures were cold pressed and sintered at different temperatures (850, 950, 1000, 1050 degrees C). The microstructure and the chemical composition of the produced Cu/Si3N4 composites were investigated by (SEM) and XRD. It was observed that the Si3N4 particles were homogeneously distributed in the Cu matrix. The density, electrical conductivity and coefficient of thermal expansion of the produced Cu/Si3N4 composites were measured. The relative green density, sintered density, electrical conductivity as well as coefficient of thermal expansion were decreased by increasing the reinforcement phase (Si3N4) content in the copper matrix. It is also founded that the sintered density and electrical conductivity of the Cu/Si3N4 composites were increased by increase the sintering temperature.