Sintering of boron carbide under high pressures and temperatures

Abstract

Sintered compacts of boron carbide were prepared by subjecting fine powder of boron carbide to high pressures and temperatures (5-6 GPa, 1000-1500°C) in the presence of a suitable binding material, namely TiC (5wt.%) or Co (5wt.%). The composites prepared by this method showed a microhardness of about 2800 kg/mm², which is very close to the microhardness of pure boron carbide. The compacts were characterized using scanning electron microscopy, and X-ray diffraction techniques. SEM study showed that the grains of boron carbide were uniformly distributed throughout the binding material and no grain growth was observed in the composites. Although composites of diameter 6.0 mm and 2-3 mm thickness are synthesized in this method, the process can be up-scaled for producing large size (12 mm diameter) composites required in various cutting tools and other applications.