Boron suboxide (B6O) materials with improved properties

The problem of low fracture toughness and the difficulties to densify has delayed the application of boron suboxide (B6O) materials as superhard materials in the industry. Therefore, in this book, efforts have been directed towards improving the fracture toughness and densification of these materials by incorporating suitable secondary phases. Possible candidates are transition metals, which form under sintering conditions a liquid phase. Therefore different Co containing additives (metal, oxide & boride) were used to densify boron suboxide powder by hot pressing. The resulting materials have a strongly improved fracture toughness (3.9 MPam1/2) and still high hardness (HV5=28.6 GPa.).