Reactive Hot Pressing of SiC/MoSi2 Nanocomposites
Abstract:Dense SiC/MoSi2 nanocomposites were fabricated by reactive hot pressing the mixed powders of Mo, Si, and nano-SiC particles coated homogeneously on the surface of Si powder by polymer processing. Phase composition and microstructure were determined by methods of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive spectrometry. The nanocomposites obtained consisted of MoSi2, -SiC, less Mo5Si3, and SiO2. A uniform dispersion of nano-SiC particles was obtained in the MoSi2 matrix. The relative densities of the monolithic material and nanocomposite were above 98%. The room-temperature flexural strength of 15 vol% SiC/MoSi2 nanocomposite was 610 MPa, which increased 141% compared with that of the monolithic MoSi2. The fracture toughness of the nanocomposite exceeded that of pure MoSi2, and the 1200°C yield strength measured for the nanocomposite reached 720 MPa.
Document Type: Research Article
Affiliations: State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
Publication date: November 1, 2007