RESEARCH ON SICP/MOSI2 COMPOSITES PREPARED BY IN - SITU REACTION ATTACHED HOT - PRESSING SYNTHESIS

摘要

MoSi: composites with different volume fraction of SiC particles were prepared by the technology of insitu reaction attached hot-pressing the pure powder of Mo, Si and C in argon atmosphere after alcohol mixing.The effects of in-situ formed SiC particles on the flexural strength,fracture toughness and microstructure of SiCP/MoSi2 composites were studied.The research shows SiCP/MoSi2 composites can be fabricated by in-situ reaction attached hotpressing technology.In addition, the relative density, flexural strength and fracture toughness of the composites are increased compared with those of the pure MoSi2 material.It is found that the in—situ formed SiC particles refine the MoSi2 grains and eliminate the brittle SiO2 glass phase.The increase of the flexural strength and fracture toughness of SiCP/MoSi2 composites is mainly attributed to the refinement of MoSi2 grains,dispersion strengthening of the in-situ formed SiC particles and elimination of the brittle SiO2 glass phase.