SiC PARTICLE REINFORCED MoSi₂ COMPOSITES

SiC particle reinforced molybdenum disilicide(MoSi₂) matrix composite has been fabricated by wet mixing and hot press sintering successfully.The microstructure and mechanical properties of the composite were determined. The experimental results showed that SiC_P/MoSi₂ composite has a phase constituent with about 20 vol% SiC and less Mo₅Si₃ in MoSi₂ matrix.Compared with unreinforced MoSi₂, the flexural strength of SiC_P/MoSi₂ composite is increased by 33% and the fracture toughness by 52% at room temperature. Compressive yield strength of SiC_P/MoSi₂ composite is increased by 44% at 1200℃ and by 53% at 1400℃. SiC_P/MoSi₂ composite has been improved in its hardness and elastic modulus.The wear resistance of SiC_P/MoSi₂ on Al₂O₃ and SiC grind wheel is very excellent. An additional SiC particle into MoSi2 matrix has reflected improvements in toughness at room temperature and strength at high temperature.