MICROSTRUCTURE-PROPERTY RELATIONSHIP IN B4C-BETA-SIC MATERIALS

The microstructure-property relationships have been studied in B4C-bet a SiC materials for boron contents from 0 to 30 wt.% (corresponding to a range from 0 to about 45 vol.% of B4C). The materials were produced by sintering or hot-pressing of composite B-Si-C powders synthesized by solid combustion. In order to characterise the microstructure quant itatively, observations of polished sections of the materials, etched by potassium salts, were made by using the scanning electron microscop y, After binarisation, the data were eventually subjected to image pro cessing. For both coexisting phases (beta SiC and B4C) the distributio n and mean values of the following microstructural parameters were det ermined: grain area, grain aspect ratio and grain dimensions. The elec trical resistivity and bending strength were also determined for the m aterials characterised microstructurally.