US Patent 7799715 Boron carbide ceramic and manufacturing method thereof

Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al2O3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.