Dense TiB2/SiC ceramic composites were fabricated by means of in-situ HIP s
ynthesis processing from TiH2, Si, C and B4C powder blends. The microstruct
ure and mechanical properties of the ceramic matrix composites were investi
gated using X-ray diffraction, optical microscopy, scanning electron micros
copy, transmission electron microscopy and microhardness. The grains of TiB
2 and SiC in the ceramic matrix composites are fine, the TiB2 grains being
regular-platelet, and the SiC grains being irregular polygon. The mechanica
l properties of the composite are mainly affected by their densities. As th
e density increases, the properties of the composites improve. The microhar
dness, fracture toughness K-IC and flexural strength are, respectively, 14.
80 GPa, 4.75 MPa m(1/2) and 408.62 MPa in the 96% density. TiB2/SiC composi
tes. The crack propagation path is deflected in these composites. TiB2/SiC
composites also have an excellent oxidation resistance. The average oxidati
on rate of TiB2/SiC is about 10(-10) m s(-1) from 1073 to 1473 K. (C) 1999
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