Microstructure and Mechanical Properties of SICP/MoSi2 Composites Manufactured by In Situ Reaction and Hot Pressing

Abstract

Pure MoSi2and MoSi2composites with different volume fraction of SiC particles were prepared by the technology of in situ reaction and hot pressing the pure powder of Mo, Si and C after alcohol mixing. The effects of in situ formed SiC particles on the microstructure, the flexural strength and fracture toughness of SiCP/MoSi2composites were studied. The research shows the relative density, flexural strength and fracture toughness of the composites are increased compared with those of the pure MoSi2material. It is found that the in–situ formed SiC particles refine the MoSi2grains and eliminate the brittle SiO2glass phase. The strengthening mechanism of the composites is of the refinement of MoSi2grains,dispersion strengthening of the in–situ formed SiC particles and elimination of the brittle SiO2glass phase.