Reaction-bonded B4C/SiC composites synthesized by microwave heating

The reaction-bonding technique was used to synthesize boron carbide (B4C) - silicon carbide (SiC) composites by microwave heating. Preforms of porous B4C were obtained by compaction followed or not by partial densification. Then, the material was infiltrated by molten silicon under a microwave heating. The influence of the thermal cycles (T: 1400-1500 degrees C, t: 5-120 minutes) is low. The hardness of boron carbide is comparable to that of alumina (15-19 GPa) for a much lower density (approximate to 2.5 g/cm(3) for B4C-based material instead of 3.95 g/cm(3) for alumina). These properties make this composite, obtained by microwave heating, a good candidate for ballistic applications.